Process for preparing a silver nanoparticles containing dispersion and use of silver nanoparticles containing mixture as coating
13 claims: 11 independent, 2 dependent
- 1Patent claims Zastrzeżenia patentowe 1. A method of producing a suspension containing silver nanoparticles, in particular for producing a bone cement or a coating agent for implants or medical instruments or an antibacterial support material, comprising the steps of 1. Sposób wytwarzania zawiesiny zawierającej nanocząstki srebra, w szczególności do wytwarzania cementu kostnego lub środka powlekającego do implantów lub instrumentów medycznych lub antybakteryjnego materiału nośnego, obejmujący etapy - preparation of silver salt, - przygotowania soli srebra, - preparation of at least one stabilizer, - przygotowania przynajmniej jednego stabilizatora, - preparation of the reducing agent, - przygotowania środka redukującego, - preparation of a polymerizable organic solvent, - przygotowania organicznego rozpuszczalnika zdolnego do polimeryzacji, - preparation of a solution of silver salt, stabilizer and reducing agent that contains water, - wytworzenia roztworu soli srebra, stabilizatora i środka redukującego, który zawiera wodę, - adding the base to the solution, - dodania zasady do roztworu, - addition of an inorganic salt, with the addition of a base, silver nanoparticles precipitate and disperse, with the aid of an inorganic salt the water remaining in the solution is hydrated and an aqueous phase is formed, while the silver nanoparticles remain mostly due to the added stabilizer in an organic polymerizable solvent, - dodania soli nieorganicznej, przy czym wraz z dodaniem zasady wytrącają się nanocząstki srebra, które dyspergują, przy czym za pośrednictwem soli nieorganicznej woda pozostająca w roztworze zostaje uwodniona i tworzy się faza wodna, podczas gdy nanocząstki srebra ze względu na dodany stabilizator w przeważającej części pozostają w organicznym rozpuszczalniku zdolnym do polimeryzacji, - oddzielenia fazy wodnej tworzącej się po dodaniu soli nieorganicznej od mieszaniny obejmującej nanocząstki srebra i stabilizatory, co sprawia, że pozostaje organiczny rozpuszczalnik z nanocząstkami srebra. - separation of the aqueous phase formed after the addition of the inorganic salt from the mixture of silver nanoparticles and stabilizers, leaving an organic solvent with the silver nanoparticles.
- 2Method for the production of a suspension containing silver nanoparticles according to the preceding claim, characterized in that at least one wetting and dispersion additive is added to the mixture comprising silver nanoparticles and stabilizers. 2. Sposób wytwarzania zawiesiny zawierającej nanocząstki srebra według wcześniejszego zastrzeżenia znamienny tym, że do mieszaniny obejmującej nanocząstki srebra i stabilizatory dodaje się przynajmniej jeden dodatek zwilżający i dyspersyjny.
- 3A method of producing a suspension containing silver nanoparticles according to one of the preceding claims, characterized in that at least one stabilizer selected from the group consisting of polyoxyethylene monoalkyl acid ester, polyoxypropylene monoalkyl acid ester, polyoxyethylene dialkyl ester and dialkyl acid, polyoxypropylene dialkyl ester and polyoxyethylene ester and trialkyl acid, polyoxypropylene ester and trialkyl acid, and mixtures thereof. 3. Sposób wytwarzania zawiesiny zawierającej nanocząstki srebra według jednego z wcześniejszych zastrzeżeń znamienny tym, że przynajmniej jeden stabilizator wybrany z grupy składającej się z estru polioksyetylenu i kwasu monoalkilowego, estru polioksypropylenu i kwasu monoalkilowego, estru polioksyetylenu i kwasu dialkilowego, estru polioksypropylenu i kwasu dialkilowego, estru polioksyetylenu i kwasu trialkilowego, estru polioksypropylenu i kwasu trialkilowego oraz ich mieszanin.
- 4Method for the production of a suspension containing silver nanoparticles according to one of the preceding claims, characterized in that an acrylate, in particular methyl methacrylate, is used as the polymerizable organic solvent. 4. Sposób wytwarzania zawiesiny zawierającej nanocząstki srebra według jednego z wcześniejszych zastrzeżeń, znamienny tym, że jako organiczny rozpuszczalnik zdolny do polimeryzacji stosowany jest akrylan, w szczególności metakrylan metylu.
- 5Method for the production of a suspension containing silver nanoparticles according to one of the preceding claims, characterized in that the addition of the base takes place continuously, in particular over a period of 5 to 48 h, such that the pH value of the formulation is between 0 and 6. 5. Sposób wytwarzania zawiesiny zawierającej nanocząstki srebra według jednego z wcześniejszych zastrzeżeń, znamienny tym, że dodawanie zasady następuje w sposób ciągły, w szczególności przez okres od 5 do 48 h, w taki sposób, że wartość pH formulacji wynosi między 0 a 6.
- 6Method for the production of a silver nanoparticle suspension according to one of the preceding claims, characterized in that the aqueous phase of the silver nanoparticle mixture containing silver nanoparticles and stabilizers is separated by decanting. 6. Sposób wytwarzania zawiesiny zawierającej nanocząstki srebra według jednego z wcześniejszych zastrzeżeń, znamienny tym, że wodna faza mieszaniny zawierającej nanocząstki srebra, obejmującej nanocząstki srebra i stabilizatory oddzielana jest poprzez zdekantowanie.
- 7Process according to one of the preceding claims, wherein the reducing agent reacts with the silver ions of the silver salt to form elemental silver and moreover, preferably with gaseous reaction products and / or where a hydrazine hydrate is used as reducing agent and / or a base is used as the base having a pKb value in the range from -2 to 10.5, preferably with a pKb value in the range of 1.5 to 9.1, particularly preferably with a pKb value in the range 3.5 to 7.5 and / or where ammonia is used as the base, potassium bicarbonate or sodium hydroxide and / or where the addition of the base takes place continuously over a period of 9 to 30 h and / or wherein the inorganic salt comprises at least one cation of period 3 or period 4 of the periodic table and at least one element of the fifth main group of the periodic table elements as anion component and / or where the inorganic salt as anion component comprises nitrogen and / or the wetting and dispersing additive is alkylphenol ethoxylate, amino functional polyester, phosphorus-containing substance or a mixture of these compounds and / or the wetting and dispersing additive being organically modified phosphate, phosphonate, polyphosphorus compound, alkylphosphonate, phosphorus compound with mixed organic ligands, oligomer or polymer with ligands containing phosphorus. 7. Sposób według jednego z wcześniejszych zastrzeżeń, przy czym środek redukujący reaguje z jonami srebra soli srebra wytwarzając pierwiastkowe srebro i oprócz tego przeważnie z gazowymi produktami reakcji i/lub przy czym jako środek redukujący stosowany jest hydrat hydrazyny i/lub przy czym jako zasada stosowana jest zasada o wartości pKb w zakresie od -2 do 10,5, korzystnie o wartości pKb w zakresie od 1,5 do 9,1, szczególnie korzystnie o wartości pKb w zakresie 3,5 do 7,5 i/lub przy czym jako zasada stosowany jest amoniak, wodorowęglan potasu lub wodorotlenek sodu i/lub przy czym dodawanie zasady następuje w sposób ciągły przez okres od 9 do 30 h i/lub przy czym nieorganiczna sól obejmuje przynajmniej jeden kation 3 okresu lub 4 okresu układu okresowego pierwiastków i przynajmniej jeden pierwiastek piątej grupy głównej układu okresowego pierwiastków jako składnik anionu i/lub przy czym sól nieorganiczna jako składnik anionu obejmuje azot i/lub przy czym w przypadku dodatku zwilżającego i dyspergującego chodzi o alkilofenol oksyetylenowany, poliester aminofunkcyjny, substancję zawierającą fosfor lub mieszaninę tych związków i/lub przy czym w przypadku dodatku zwilżającego i dyspergującego chodzi o organicznie zmodyfikowany fosforan, fosfonian, związek polifosforowy, alkilofosfonian, związek fosforu z mieszanymi organicznymi ligandami, oligomer lub polimer z ligandami zawierającymi fosfor.
- 8A silver nanoparticle-containing slurry obtainable by a method according to any one of the preceding claims, comprising:silver nanoparticles, at least one stabilizer selected from the group consisting of polyoxyethylene monoalkyl acid ester, polyoxypropylene monoalkyl acid ester, polyoxyethylene dialkyl acid ester, polyoxypropylene dialkyl acid ester, polyoxyethylene trialkyl ester and polyoxypropyl acid ester and polyoxypropyl acid ester and their polyoxypropyl acid ester , and at least one nonionic surfactant as wetting and dispersing additive, wherein the silver nanoparticles are dispersed in a liquid monomer, prepolymer or polymer, and wherein the silver nanoparticles are surrounded by at least one stabilizer and by a wetting and dispersing additive. 8. Zawiesina zawierająca nanocząstki srebra możliwa do wytwarzania sposobem według jednego z wcześniejszych zastrzeżeń, obejmująca: nanocząstki srebra, przynajmniej jeden stabilizator wybrany z grupy składającej się z estru polioksyetylenu i kwasu monoalkilowego, estru polioksypropylenu i kwasu monoalkilowego, estru polioksyetylenu i kwasu dialkilowego, estru polioksypropylenu i kwasu dialkilowego, estru polioksyetylenu i kwasu trialkilowego oraz estru polioksypropylenu i kwasu trialkilowego i ich mieszanin, i przynajmniej jednego niejonowego związku powierzchniowo czynnego jako dodatku zwilżającego i dyspergującego, przy czym nanocząstki srebra zdyspergowane są w płynnym monomerze, prepolimerze lub polimerze, i przy czym nanocząstki srebra otoczone są przez przynajmniej jeden stabilizator i przez dodatek zwilżający i dyspergujący.
- 10A suspension containing silver nanoparticles according to one of the preceding claims 8 or 9, characterized in that the average size of the nanoparticles is between 5 and 50, preferably between 10 and 20 nm and / or that at least 90, preferably at least 99% of the silver nanoparticles are smaller than 50 , preferably smaller than 20 nm, and / or that the silver nanoparticles have a substantially spherical shape and / or that the proportion of silver nanoparticles is between 0.5 and 5, preferably between 1 and 3% by weight and / or that the polymer comprises an acrylate or an acrylate procursor, in particular methyl methacrylate. 10. Zawiesina zawierająca nanocząstki srebra według jednego z wcześniejszych zastrzeżeń 8 lub 9, znamienna tym, że średnia wielkość nanocząstek mieści się między 5 a 50, korzystnie między 10 a 20 nm i/lub że przynajmniej 90, korzystnie przynajmniej 99% nanocząstek srebra jest mniejszych niż 50, korzystnie mniejszych niż 20 nm, i/lub że nanocząstki srebra posiadają zasadniczo sferyczny kształt i/lub że udział nanocząstek srebra wynosi między 0,5 a 5, korzystnie między 1 a 3% wagowych i/lub że polimer obejmuje akrylan lub prokursor akrylanu, w szczególności metakrylan metylu.
- 11Use of a suspension containing silver nanoparticles according to one of the preceding claims 8 to 10 as a monomer, in particular for bone cement, a coating solution or an additive for polymeric materials, in particular for plastic implants. 11. Zastosowanie zawiesiny zawierającej nanocząstki srebra według jednego z wcześniejszych zastrzeżeń 8 do 10 jako monomeru, w szczególności do cementu kostnego, roztworu powlekającego lub dodatku do materiałów polimerycznych, w szczególności na implanty z tworzyw sztucznych.
- 13Use according to the preceding claim 12, wherein the stabilizers are selected from the group consisting of sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan tri-stearate, polyoxyethylene sorbitan trioleate, polyoxyethylene, sorbitan monolaurate, polyoxyethylene monooleate, polyoxyethylene monostearate, polyoxyethylene, polyoxyethylene glycerol monoricinoleate, castor oil, hydrogenated castor oil, soybean oil and mixtures thereof, and / or where the stabilizers are present in a quantity ranging from 1:1 to 2: 1 and / or where the silver nanoparticles are present in particle sizes from 1 to 100 nm, preferably from 1 to 50 nm, particularly preferably from 1 to 20 nm. 13. Zastosowanie według wcześniejszego zastrzeżenia 12, przy czym stabilizatory wybrane są z grupy składającej się z monolaurynianu polioksyetylenosorbitanu, monopalmitynianu polioksyetylenosorbitanu, monostearynianu polioksyetylenosorbitanu, monooleinianu polioksyetylenosorbitanu, tri stearynianu polioksyetylenosorbitanu, trioleinianu polioksyetylenoglicerolu, monolaurynianu polioksyetylenoglicerolu, monooleinianu polioksyetylenoglicerolu, monostearynianu polioksyetylenoglicerolu, monorycynooleinianu polioksyetylenoglicerolu, oleju rycynowego, uwodornionego oleju rycynowego, oleju z nasion soji i ich mieszanin, i/lub przy czym stabilizatory obecne są w stosunku ilościowym w zakresie od 1 : 1 do 2 : 1 i/lub przy czym nanocząstki srebra występują w wielkości cząstek od 1 do 100 nm, korzystnie 1 do 50 nm, szczególnie korzystnie 1 do 20 nm. aap Implantate AG Pełnomocnik: aap Implantate AG Representative: Fig. 1 Fig. 1 300 350 400 450 500 550 600 650 700 750 300 350 400 450 500 550 600 650 700 750 Długość fal [nm] Wavelength [nm] Fig. 2 Fig. 2 Diameter nm Średnica nm Fig. 3 Fig. 3 Fig. 4 Fig. 4 Fig. 5 Fig. 5 Fig. 6 Fig. 6 Fig. 7 Fig. 7 Fig. 9 Fig. 9 Fig. 10 Fig. 10 Washed silver content [ppb] Wymyta zawartość srebra [ppb] 250 250 200 200 150 150 100 100 Fiber number Numer włókna Antimicrobial inhibitory effect [%] Antymikrobiotyczne działanie hamujące [%]
Independent claims11
385 paragraphs, as filed
Description
Technical field
[0001] The invention relates to a coating material with a dispersion formulation containing silver nanoparticles, and to a method of their preparation and their use, in particular as a coating agent.
State of the art
[0002] The biocidal activity of silver is known. Especially in the medical field, in the case of implants, there are more and more attempts to limit the use of antibiotics or to completely abandon the use of antibiotics. Silver is an effective alternative.
[0003] Until now, the problem has been that the added silver particles, in particular in the case of bone cement, do not achieve a sufficient effect. It is presumed that this is due to the usually too small specific surface area of the material used.
[0004] Bone cement is generally a material that hardens as a result of a polymerization reaction. In practice, for example, bone cement based on methyl methacrylate is known. It usually consists of two components, namely a liquid component and a solid component. The solid component may comprise a largely polymerized pearlescent polymer as well as a polymerization initiator and other components by means of which, for example, the reaction rate is controlled. The monomeric component comprises a monomer or prepolymer with which, when a liquid component is mixed with a solid component, a polymerization reaction is triggered which hardens the mass initially pasty to form a solid. Bone cement is used, for example, for use in endoprostheses, for the production of strut elements, for multi-part dentures, and for vertebroplasty and kyphoplasty. Depending on the desired purpose of use, bone cements with different strength and hardening properties can be prepared.
[0005] It is known to add an antibiotic such as gentamicin to ensure an antibiotic effect.
[0006] Also in the case of bone cement and polymerizable coating materials, it would be desirable to add silver in addition or as an alternative to achieve an antimicrobial effect.
[0007] Due to the particular properties, in particular of the larger specific surface area, it would be particularly desirable to add nanoparticle silver. The addition of nanoparticle silver to the solid component generally fails because it would be almost impossible to make nanoparticle silver available in the solid state due to its agglomeration.
The addition of silver in the liquid phase is also difficult because, on the one hand, agglomeration effects occur and, moreover, it has not been possible to date to provide a sufficiently stable suspension with nanoparticle silver, which remains dispersed also in non-polar and low-polar liquids such as methyl methacrylate.
[0009] Following the general definition of "nanoparticles" it is the term for particles that have a size in the range below 100 nm. The use of the prefix "nano" thus represents, according to the official definition of ISO TC 229, a particle demarcation in the sub-micrometer range (> 100 nm). In general, it should be assumed that substances called nanomaterials have altered chemical and physical properties. In the case of nanometals, e.g. gold and silver have different colors to the corresponding metals, namely red or yellow.
Moreover, it has been scientifically proven that nanoparticles of a given substance have an increased surface energy. The smaller the particles are, the higher their surface energy is. As a consequence, nanoparticles should generally be regarded as unstable as, due to their high surface energy, they easily react to new compounds or larger, more stable aggregates. For example, nanometals, this means that even noble metal particles oxidize rapidly with oxygen from the air as soon as the particle size is in the nanometer range.
[0011] Technologically useful nanoparticles are thus obtained only when their surface is chemically or physically protected and thus stabilized. "Technologically useful" can be termed nanoparticles that consistently retain or maintain their original particle size from their production through processing to use.
[0012] The possibility of stabilizing nanoparticles in suspensions is known in the art. There are three important ways to make metallic nanoparticles. In the first method, nanoparticles are supported on solid substances for stabilization. The solids are always in a stable size in the micrometer range. The disadvantage of using the products thus prepared is, on the one hand, the loss of size in the nano-scale range and, on the other hand, the high filler load.
The filler used, which serves as the basis for the formation of the metal nanoparticles, has a grain size in the micrometer range and is e.g. completely unsuitable for the production of thin structures or fibers. In practice, the proportion by weight of the filler is also a multiple of the proportion of nanometal by weight.
[0013] In the fire-chemical vapor deposition processes, a cluster of micro- and nanoparticles is formed as a solid that first requires costly redispersion for further use, which is often no longer entirely possible due to the effects of storage . Moreover, the distribution of nanoparticles can never be optimal, as it can at most be as good as the distribution of the microparticles on which they are deposited.
[0014] The second procedure is the synthesis of metal nanoparticles by stabilization with polymers such as polyvinylpyrrolidone in a polyol process, which has been repeatedly described in the literature as the standard method. However, only low concentrations of metal nanoparticles are obtained (range below 0.1 wt% silver).
[0015] A third variant for producing metal nanoparticles is the PVD (Physical Vapor Deposition) process in which the base metal is vaporized. In order to stabilize the nanoparticles produced in this way, polymers or silicones are again used. Generating metal vapor is a very energy-intensive process that requires vacuum process chambers. Such production methods are therefore wasteful. In addition, the polymers and silicones used during further processing pose significant problems in the process technology, since redispersion is often impossible.
Furthermore, DE 10 2006 056 284 A1 discloses the preparation of an aqueous suspension with an antimicrobial effect by mixing an aqueous suspension of particles of the order of nano size, which contain at least one metal having an antimicrobial effect, with an aqueous suspension of a polymerization, polycondensation or polyaddition product. The production of silver nanoparticles occurs through chemical reduction in water. Sodium chloride is used to stabilize the silver nanoparticles
[0017] A disadvantage, which all production variants show, is the difficult processing of metal nanoparticles in polymer melts, such as, for example, when adding additives to thermoplastic polymers. The solids cannot be incorporated homogeneously without first dispersing them.
[0018] There is therefore still a need for stable suspensions of silver nanoparticles with obesity antimicrobial properties.
[0019] Document US 2008/181931 A1 shows the addition of a stabilizer and the formation of nanoparticles in situ. US 2007/003603 A1 teaches the use of an aqueous or non-aqueous suspension as a coating agent for implants. Document JP 2008231489 A shows the production of nano-sized metal particles in micelles.
Presentation of the invention
[0020] The basis of the invention as it is characterized in the claims is the task of providing a stable suspension of silver nanoparticles which are used, but can also be used in particular in bone cement or as an antibacterial coating for implants and medical devices.
[0021] In particular, the suspension is used in bone cements and polymer-based coating materials.
[0022] The object of the invention is already solved by a method for producing a silver nanoparticle-containing suspension, by a silver nanoparticle-containing suspension, and by using a mixture containing silver nanoparticles according to one of the independent claims. Further advantageous details, aspects and embodiments of the present invention emerge from the dependent claims, description, examples and figures.
[0023] The invention relates, on the one hand, to a method for the preparation of a suspension containing silver nanoparticles. This suspension should be used in particular for the production of bone cement or as a coating agent, in particular for implants and medical instruments. It is also intended to be used as an antibacterial backing material, both in the field of medicine and in clothes and utility items.
[0024] According to the invention, a silver salt and stabilizer are provided.
[0025] Further, a reducing agent and a polymerizable organic solvent are provided. Suitable polymerizable organic solvent are, in particular, polymers or prepolymers which can then be used, for example, as a coating agent or as a component of bone cement.
[0026] A solution is prepared from the silver salt, the stabilizer and the reducing agent.
[0027] After the solution is made, the base is added as well as the inorganic salt.
[0028] With the addition of a base, nanoparticles precipitate and disperse.
[0029] The water remaining in solution is hydrated with the aid of the inorganic salt. The aqueous phase then forms, while the silver nanoparticles, due to the added stabilizer, mostly remain in the polymerizable organic solvent. The aqueous phase can then be separated, for example decanted, with the result that an organic solvent capable of polymerization with the silver nanoparticles remains again.
[0030] By the invention, a substantially water-free monomer or prepolymer containing silver nanoparticles, for example an acrylate, in particular methyl methacrylate or butyl acrylate, can therefore be provided.
[0031] It will be understood that a certain proportion of water may remain in the organic solvent since small amounts of water are soluble in, for example, methyl methacrylate.
[0032] However, an essentially organic polymerizable solution remains, which can, for example, be used as a coating material or as a component of a polymerizable material, in particular bone cement.
The invention further relates to a suspension containing silver nanoparticles, which is in particular used as a bone cement, an antibacterial support material or a coating agent.
[0034] The silver particle-containing solution comprises silver nanoparticles, at least one stabilizer, and at least one wetting and dispersing additive, the silver nanoparticles dispersed in a liquid monomer, prepolymer, or polymer.
The invention is based on the discovery that by means of a stabilizer as well as a further wetting and dispersing additive, it is possible to prepare a suspension in an organic liquid, for example acrylate with silver nanoparticles, which is also stable over a longer period of time.
[0036] The stabilizer is preferably selected from the group consisting of polyoxyethylene monoalkyl acid ester, polyoxypropylene monoalkyl acid ester, polyoxyethylene dialkyl acid ester, polyoxypropylene dialkyl acid ester, polyoxyethylene trialkyl ester, polyoxypropylene and trialoxypropylene acid ester and trialkylic acid. their mixtures.
[0037] As wetting and dispersing additive, a nonionic surfactant, in particular an organosilicon surfactant, is preferably used.
[0038] The inventors presume that the nanoparticles are surrounded by a stabilizer and then a wetting and dispersing agent as a second layer.
While the stabilizer serves, in particular in the first production step, for the nanoparticles to precipitate in the aqueous solution and not to agglomerate, the wetting and dispersing additive ensures that the nanoparticles also remain dispersed in a low-polar organic liquid. The suspension containing silver nanoparticles can be used, for example, as a monomer, in particular for the production of bone cement, for a coating solution or as an additive to polymeric materials.
The polymer used is in particular an acrylate or an acrylate precursor, in particular methyl methacrylate. In one embodiment, a mixture comprising silver nanoparticles is used, including silver nanoparticles and at least one stabilizer selected from the group consisting of polyoxyethylene monoalkyl acid ester, polyoxypropylene monoalkyl ester, polyoxyethylene dialkyl ester and dialkyl acid, polyoxypropylene ester and dialkyl ester, polyoxyethylene ester and dialkyl ester. and trialkyl acid and polyoxypropylene ester and trialkyl acid. [0041] Such a mixture which is used for the bone cement according to the invention or the coating agent will be described in detail below.
[0042] Herein, all data on percentages in wt. relate to the weight of the entire formulation as 100% base.
[0043] The mixture used comprises at least one stabilizer selected from the group consisting of polyoxyethylene monoalkyl acid ester, polyoxypropylene monoalkyl acid ester, polyoxyethylene dialkyl acid ester, polyoxypropylene dialkyl acid ester, polyoxyethylene trialkyl ester and polyoxypropylene acid ester and trialkylic acid ester . The pr perature and flow rate of these stabilizers are compounds having surface-active agents from the group of nonionic surfactants, which at room temperature are in liquid form. Non-ionic surfactants within the meaning of the invention are chemical interfacial surfactants which have uncharged polar and non-polar regions in one molecule. In addition, nonionic surfactants do not have dissociable functional groups.
[0044] The mixture containing silver nanoparticles according to the invention contains dispersion stabilized silver nanoparticles which cannot aggregate to larger agglomerates because the used stabilizers are fluid in the temperature range from 0-240 ° C. In contrast, the prior art has, for example, many products with silver nanoparticles in stock, which are offered as dry powders, which, however, due to their tendency to agglomerate during transport and storage for dispersion in organic solvents such as methyl methacrylate, can be redispersed only with a high input of mechanical energy, and then also only incompletely.
[0045] Combinations of interfacial surfactant components from the abovementioned chemical classes are particularly preferred for use in the present invention. According to a particularly preferred embodiment, at least two stabilizers are therefore present in the mixture.
When more than one stabilizer is present, they can be different stabilizers of one of the classes of chemical compounds mentioned or they can be stabilizers of different classes of compounds. In the case of a combination of three different stabilizers, for example, three different polyoxyethylene monoalkyl acid esters can be used, but, for example, also two different polyoxyethylene monoalkyl acid esters and one polyoxypropylene monoalkyl ester or, for example, one polyoxypropylene dialkyl ester, one polyoxyethylene ester and trialkylic acid and one polyoxypropylene trialkyl ester. Any combination of such nonionic surfactants is possible.
[0047] It is particularly preferred that the stabilizer mixture consists of a combination of nonionic surfactants from the two different classes of compounds mentioned above.
[0048] According to a particularly preferred embodiment, the selected stabilizer or stabilizers (s) is / are from the group consisting of polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan tri-stearate, polyoxyethylene glycerol trioleate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monooleate, polyoxyethylene glycerol monostearate, polyoxyethylene glycerol monoricinoleate, castor oil, hydrogenated castor oil and soybean oil.
[0049] In many cases the stabilizers are not known under their chemical name, but under their respective trade names. Preferred stabilizers within the scope of the present invention are Tween20 ™, Tween40 ™, TweenoO ™, Tween80 ™, Polysorbat ™, Tagat TO ™, Tagat TO V ™, Tagat L2 ™, Tagat S2 ™, Tagat R40 ™, Triton X 100 ™, Hydrogenated Castoroil ™, PEG 20 Glycerylstearat ™, PEG 20 Glyceryllaurat ™, PEG 40 Castoroil ™, PEG 25 Glyceryltrioleat ™, Newcol ™, Montana ™, Lonzest ™, Liposorb ™, Nonion ™, Kuplur ™, lonet ™, Kemotan ™, Grillosan ™, Ethylan ™, Glycomul ™, Emsorb ™, Disponil ™, Amisol ™, Armotan ™, Sorbax ™, Sorbitan ™, Span ™ and the Tego
Pearl ™
[0050] The above list of stabilizers is not exhaustive as different manufacturers market the same or similar products under different names or new nonionic surfactants of the above-mentioned classes of compounds will be synthesized in the future and may also be used in the mixture according to the invention.
[0051] If at least two stabilizers are present in the mixture, they are present in the mixture preferably in an amount ratio ranging from 1: 1 to 2: 1.
[0052] Since the nonionic surfactants contained in the mixture act as stabilizers for the formed nanometal, there is a quantitative relationship between the concentrations of the stabilizer and the metal. According to a further preferred embodiment, the quantitative ratio of the silver nanoparticles to the stabilizer is in the range from 10: 2 to 10:50, particularly preferably in the range from 10: 5 to 10: 10. If more stabilizers are present, then by "metal to stabilizer ratio" it is meant "metal ratio to the sum of stabilizers present". With the use of advantageous quantitative ratios, mixtures are obtained from which particularly stable metal nanoparticle suspensions can be produced, which can be used universally. Preferably the metal nanoparticles have a particle size of 1 to 100 nm, more preferably 1 to 50 nm, particularly preferably 1 to 20 nm.
[0053] The present invention also relates to a silver nanoparticle containing formulation comprising a suspension of one of the above-described mixtures containing metal nanoparticles. The formulation according to the invention is fluid and, moreover, does not contain any solid by-components that would limit the possibilities for further use.
[0054] In the mixture according to the invention, as well as in the formulation according to the invention, one or more surface-active components are included as stabilizers, which, in addition to stabilizing the silver nanoparticles, also enable further processing (by redispersion, emulsification) to all other substrates. The most technologically advanced further processing is processing in thermoplastics. The temperatures used are up to 300 ° C. Up to such a temperature, it is desirable that the formulation used to introduce the performance additives is flowable, which is satisfied by the use of one or more interface surfactants which are flowable up to a temperature of 300 ° C for a short time. At least two stabilizers are particularly preferably present in the formulation. If a greater number of stabilizers are present, they can be different stabilizers of one of the classes of chemical compounds mentioned or stabilizers of different classes of compounds. In the case of a combination of three different stabilizers, for example, three different polyoxyethylene monoalkyl acid esters can be used, but also, for example, also two different polyoxyethylene monoalkyl acid esters and one polyoxypropylene monoalkyl acid ester or, for example, one polyoxypropylene dialkyl ester, one ester polyoxyethylene trialkylic acid and one polyoxypropylene trialkyl ester. Any combination of such nonionic surfactants is possible.
[0055] It is particularly preferred that the stabilizer mixture consists of a combination of non-ionic surfactants from the two different classes of compounds mentioned above.
[0056] Since at least one nonionic surfactant is used as a stabilizer for the formed nanometal, there is a quantitative relationship between the concentrations of the stabilizer and the silver. The formulation according to the invention for use in, for example, methyl methacrylate has an amount ratio of silver to the stabilizer in the range 10: 2 to 10:50. Preferably the ratio of metal to stabilizer is 10: 5 to 10:20, particularly preferably 10: 6 to 10. : 10. If several stabilizers are present, then by "metal to stabilizer ratio" is meant "metal ratio to the sum of stabilizers present". Using advantageous quantitative ratios, particularly stable silver nanoparticle suspensions are obtained. Preferably more than two stabilizers are present in the formulation of the invention. In this case, the content of the first stabilizer is in the range from 30 to 90% by weight, preferably between 40 to 60% by weight, particularly preferably between 45 to 55% by weight. The proportion by weight remaining up to 100% is divided between the other stabilizers according to the invention used in the combination, which for their part can be divided into proportions of 0 to 100% by weight. The data mentioned here in wt.%. therefore, unlike the rest of the data, they refer to the total weight of the stabilizers as the basis of 100%.
[0057] It is particularly preferred that one or more stabilizers are present in the formulation, selected from the group consisting of Tagat TO V ™, Tween20 ™, Tween80 ™ and Tagat L2 ™. With the use of such stabilizers, particularly stable suspensions for universal use are obtained.
[0058] According to one particularly preferred embodiment of the present invention, a mixture of Tagat TO V ™ and Tween20 ™ is present in the formulation as stabilizer. Formulations in which the ratio of Tagat TO V ™ to Tween20 ™ is in the range 1: 2 to 2: 1 are particularly preferred, and formulations in which the ratio of Tagat TO V ™ to Tween20 ™ is approximately 1: 1 are particularly preferred. .
[0059] With regard to particle size, reference should be made once again to the definition made at the beginning, according to which the silver nanoparticles have a particle size below 100 nm. In the formulation according to the invention, the silver nanoparticles are present in a particle size of 1 to 100 nm, preferably 1 to 50 nm, particularly preferably 1 to 20 nm. The structure of silver nanoparticles can have the shape of triangles, cubes, spheres, bars or plates.
[0060] Preferably the formulation comprises nano-sized stable metal particles in a concentration of 0.5 to 60 wt%, the quantity ratio of the silver nanoparticles to the stabilizer being in the range of 10: 2 to 10:50, preferably in the range of 10: 5 to 10:10. In the preferred ranges, particularly stable suspensions of silver nanoparticles are obtained which can be used universally.
Silver nanoparticles in a proportion of 1 to 40% by weight, preferably in a proportion of 5 to 30% by weight, are particularly preferably present in the formulation. An organic solvent is used to prepare the slurry. It is then a suspension of one of the above-described mixtures containing silver nanoparticles in an organic solvent. The organic solvent is particularly preferably methyl methacrylate.
[0062] The present invention also includes a process for the preparation of the above-described metal nanoparticle-containing dispersion formulations comprising the steps of preparing a metal salt, preparing at least one stabilizer selected from the group consisting of polyoxyethylene monoalkyl acid esters, polyoxypropylene monoalkyl acid esters, polyoxyethylene dialkyl esters and , polyoxypropylene dialkylic acid esters, polyoxyethylene trialkyl esters, esters of polyoxypropylene and trialkylic acid, preparation of the reducing agent, preparation of the solvent, preparation of the solution of the metal salt, stabilizer and reducing agent, addition of the base to the solution, with the addition of the base in a continuous manner over a period of 5 to 48 h, so that the pH of the formulation is between 0 and 6.
[0063] With the production method according to the invention, a formulation with a very narrow nanoparticle size distribution is obtained. An organic solvent is used as the solvent.
[0064] Preferably the addition of the base takes place continuously over a period of 9 to 30 hours. In this way, a formulation with a particularly narrow nanoparticle size distribution is obtained.
[0065] The production method according to the invention is a chemical deoxidation process. Accordingly, the silver nanoparticles are produced by chemical reduction from their salts. In principle, any chemical or physical reducing agent can be used to produce the silver nanoparticles of the invention. By physical reducing agents, it is meant increasing the temperature or irradiation with light. The use of a chemical reducing agent is advantageous, since here 100 percent material transformations and very high reaction rates can be achieved.
It has surprisingly been found that in the presence of at least one stabilizer from the group of polyoxyethylene monoalkyl esters, polyoxypropylene monoalkyl acid esters, polyoxyethylene dialkyl acid esters, polyoxypropylene dialkyl acid esters, polyoxyethylene trialkyl esters and polyoxypropylene esters, in trialkylic acid, very strong reducing agents can be used, leading to an increased reaction rate, without the simultaneous danger of forming a greater proportion of large, undesirable silver particles.
[0067] Of the chemical reducing agents, preferred are those that do not generate reaction by-products remaining in the reaction mixture, such as the corresponding oxidized form of the reducing agent in question, which would degrade the quality of the silver nanoparticle-containing aqueous dispersion formulation. According to a preferred embodiment, a reducing agent is thus used which reacts with the metal ions of the metal salt to form elemental metal and, moreover, predominantly gaseous reaction products.
[0068] Reducing agents which, in their oxidized form, can leave the reaction solution as gaseous substance, such as, for example, hydrazine hydrate, are particularly preferred. Of course, the silver nanoparticles according to the invention can also be obtained with any other reducing agent.
[0069] Reducing metal production can be formulated as a pair of redox equations. The first half equation is the reduction equation whereby the metal ion of the metal salt is reduced to elemental metal. The second half equation describes the corresponding oxidation transition - the oxidation of the reducing agent to the corresponding oxidized product which ideally leaves the gaseous reaction solution. Common to all reducing agents is that for each electron transferred, one proton is formed. Such a proton contributes to the fact that the pH value of the entire reaction solution drops very sharply. Lowering the pH value causes the reaction to stop undesirably. Therefore, lye has to be added to capture the protons that are formed, which inhibit the summation reaction.
[0070] It has been surprisingly found that the type of lye, the concentration of the lye and the rate at which the lye is added are decisive for the nanoparticle size distribution in the resulting formulation.
[0071] Preferably, ammonia, potassium hydrogen carbonate or sodium hydroxide is used as the base. Using such bases, particularly stable suspensions with a narrow nanoparticle size distribution are obtained.
The amount of lye added must be calculated so that the pH of the suspension is neutral after the reaction has ended. The pH value is then between pH 5 and pH9.
[0073] Liquids or proton acceptors are defined by their pKb values. The pKb value is the negative decimal logarithm of the equilibrium concentration of the protons and thus a measure for base strength.
[0074] Bases which have a pKb value in the range -2 to 10.5, preferably 1.5 to 9.1, particularly preferably in the range 3.5 to 7.5 are suitable for the preparation of the formulations according to the invention.
In addition to the strength of the base, the rate of addition to the reaction solution for the preparation of the formulations according to the invention is decisive here. If the addition is too fast then the particle size spectrum shifts towards the larger particles, which are in the extreme case in the micrometer range. If, on the other hand, the addition is too slow, then no material yields above 90% are obtained, since the nanometal already formed causes catalytically decomposition of the reducing agents and thus there is no longer a reagent for the production of silver nanoparticles.
[0076] Experiments have shown that the lye rate for a 50 kg batch size should be in the range of 9 to 30 hours to achieve the inventive high quality of silver nanoparticles. With correspondingly smaller batch sizes, the lye addition time is likewise reduced. The upper limit of the addition time cannot be extended arbitrarily, because the catalytic decomposition of the reducing agent through the already formed nanometal after 48 h at the latest has a significant negative effect on the overall reaction yield.
[0077] The rate of the alkali addition is such that the pH of the slurry is constantly between 0 and 6. A higher pH leads to a reaction that is too fast and thus to uncontrolled particle growth. Too low a pH value causes the reaction to stop and thus no more nanometal is formed.
[0078] The formulation according to the invention can be used in many applications, with clearly advantageous properties being achieved in the most diverse applications. The metal nanoparticles of the formulation according to the invention or the metal nanoparticles of the formulation according to the invention can be incorporated into various substrates, in particular in order to obtain antimicrobial activity.
The present invention further relates to a method of preparing a bone cement or coating agent for implants or medical instruments with one of the mixtures containing silver nanoparticles more closely described above, wherein an inorganic salt is added to one of the above-described silver nanoparticle formulations, or after carrying out one of the methods of preparation of the formulation described above, an inorganic salt is added, wherein the inorganic salt comprises at least one element of a fourth or fifth main group of the Periodic Table of the Elements as an anion component.
[0080] The present invention includes
- a method of producing a mixture containing silver nanoparticles, including silver nanoparticles and at least one stabilizer selected from the group consisting of polyoxyethylene monoalkyl acid ester, polyoxypropylene monoalkyl acid ester, polyoxyethylene dialkyl acid ester, polyoxypropylene dialkyl acid ester and polyoxyethylene trial acid ester and polyoxypropylene trialkyl ester, including the steps
- preparation of silver salt,
- preparation of at least one stabilizer selected from the group consisting of polyoxyethylene monoalkyl acid ester, polyoxypropylene monoalkyl acid ester, polyoxyethylene dialkyl acid ester, polyoxypropylene dialkyl acid ester, polyoxyethylene trialkyl ester and polyoxypropylene ester and trialinkyl acid thereof,
- preparation of the reducing agent,
- preparation of the solvent,
- preparation of silver salt solution, stabilizer and reducing agent,
- adding a base to the solution, wherein the addition of the base takes place continuously over a period of 5 to 48 hours such that the pH of the formulation is 0 to 6.
- adding an inorganic salt, the inorganic salt comprising at least one element of the fourth or fifth main group of the Periodic Table of the Elements as an anion component.
[0081] The mixture according to the invention containing nanoparticles can thus be obtained by adding an inorganic salt from a suitable formulation containing nanoparticles.
[0082] Particularly when preparing a mixture containing nanoparticles from a formulation containing nanoparticles that was obtained by reducing the silver salt in solution, the addition of an inorganic salt has unique advantages. It has surprisingly been found that the addition of inorganic salts divides the suspension obtained by adding the base to the solution of the silver salt, the stabilizer and the reducing agent into two chemical phases 1 and 2. Phase 1 contains the silver nanoparticles in the used liquid stabilizer mixture. The solvent, the inorganic salts and the ammonium nitrate by-product are in phase 2 above phase 1. The two phases can now be separated from each other simply by pouring off the upper phase 2. Phase 1 remains, which now consists of silver nanoparticles and liquid stabilizers.
[0083] Suspended silver nanoparticles, which as a rule have a particle size of 1-20 nm and are chemically stabilized, are thus separated from the ammonium nitrate by-product and the solvent used in the suspension. The silver nanoparticle formulations according to the invention can be made available through additional fields of application.
[0084] In order to characterize the respective salts in more detail, their cationic and anionic components should be analyzed separately. Salts generally consist of at least one cation and at least one anion. Undesirable interaction of the cations with the stabilized formulation containing metal nanoparticles is not to be expected as the silver used exists either as an uncharged metal or as a positively charged cation.
The choice of anions is here limited by the fact that undesired interactions with the silver cations present must be avoided. In this way, all anions that form sparingly soluble compounds with the silver used, e.g. halides, chalcogenides and their oxygen compounds, fall off.
[0086] It is therefore particularly preferred that the inorganic salt comprises at least one element of the fifth main group of the Periodic Table of the Elements as an anion component, the inorganic salt particularly preferably comprising nitrogen as an anion component.
[0087] It is particularly advantageous to then decant the phase formed after the addition of the inorganic salt from the mixture containing silver nanoparticles, consisting essentially of silver nanoparticles and stabilizers.
[0088] The present invention further relates to a method for preparing one of the silver nanoparticle containing formulations described above, comprising the steps of preparing one of the silver nanoparticle containing mixtures described above, preparing a solvent, adding a mixture containing silver nanoparticles to a solvent. The present invention thus includes a method for making a silver nanoparticle containing formulation comprising a suspension of a silver nanoparticle containing mixture comprising silver nanoparticles and at least one stabilizer selected from the group consisting of polyoxyethylene monoalkyl ester, polyoxypropylene ester and monoalkyl acid, polyoxyethylene ester and dialkyl acid ester, polyoxypropylene and dialkylic acid, polyoxyethylene trialkylic acid ester and polyoxypropylene trialkylic acid ester, comprising the steps of preparing a mixture containing silver nanoparticles, including silver nanoparticles and at least one stabilizer selected from the group consisting of polyoxyethylene ester and monoalkyl acid, polyoxypropylene ester and monoalkylene acid, and polyoxyalkylene ester dialkylic acid, polyoxypropylene ester and dialkylic acid, polyoxyethylene ester and trialkylic acid and polyoxypropylene ester and trialkylic acid, preparing the solvent, adding the mixture containing silver nanoparticles to the solvent.
[0089] The chemically stabilized silver nanoparticles according to the invention can be wetted or dissolved by a solvent without losing the stabilizer coating necessary for stabilization. The solvent is an organic solvent. All organic, protic, aprotic, polar and non-polar compounds or mixtures thereof can be used.
[0090] According to a particularly preferred embodiment of the present invention, at least one wetting and dispersing additive is additionally added. Wetting and dispersing aids ensure that the silver nanoparticles are wetted or dissolved by the solvent used.
[0091] Suitable chemicals that can be used as wetting and dispersing additives are alkylphenol ethoxylates, amino-functional polyesters, phosphorus-containing substances, such as, for example, organically modified phosphates, phosphonates, polyphosphoric compounds and alkylphosphonates, or a mixture of these compounds.
The wetting and dispersing additive is particularly preferably an organically modified phosphate, a phosphonate, a polyphosphorus compound, an alkylphosphonate, a phosphorus compound with mixed organic ligands, an oligomer or a polymer with phosphate-containing ligands.
[0093] Such wetting and dispersing additives are available from Evonic, BYK Chemie and Ciba Geigy.
[0094] Chemically stabilized silver nanoparticles with a preferred particle size of 1-20 nm can therefore be introduced with the aid of wetting and dispersing additives, e.g. in organic solvents, in particular methyl methacrylate. Such incorporation can occur by the simplest mixing or mixing techniques since it is not necessary to redisperse the metal nanoparticles by the use of the stabilizers of the invention. In this way, stable suspensions of, for example, silver nanoparticles with a particle size preferably below 20 nm in organic solvents, preferably methyl methacrylate, at a concentration of 5,000 mg / kg to 50,000 mg / kg of silver content are obtained.
[0095] The invention relates in particular to a bone cement, an antibacterial support material or a coating agent, in particular an acrylate-based coating agent which can be produced by the method described above.
[0096] The invention further relates to a bone cement, an antibacterial support material or a coating agent for implants or medical devices, including silver nanoparticles.
[0097] The coating agent is in particular a liquid coating agent, for example an acrylate or a silicone. The coating agent can, for example, be applied by dipping (dip coating).
[0098] According to the invention, the nanoparticles are surrounded by at least a first and a second stabilizer and dispersed in the polymer.
[0099] By polymer is to be understood any form of prepolymer as well as also a substantially unreacted monomeric solution which, for example, predominantly comprises methyl methacrylate.
[0100] The inventors have found that by using two different stabilizers, in particular by using two emulsifiers, it is possible to prepare a stable suspension which is retained also in non-polar liquids.
[0101] A suitable starting material in particular is the formulation as described above, in which it can be imagined that it already comprises silver nanoparticles with a shell of at least one stabilizer.
[0102] But also during such a formulation it is not always certain that no symptoms of precipitation and agglomeration will occur.
[0103] The inventors have, however, discovered that by selecting a second stabilizer, believed to form a second shell around the first stabilizer, a stable suspension can be prepared in a non-oily liquid.
[0104] For this purpose, in particular a nonionic surfactant is used, in particular an organosilicon surfactant. A surfactant of this type is available, for example, under the trade name Tego DISPERS 655.
In particular, at least 0.1, preferably at least 0.2% of the second stabilizer is added to the mix, i.e., for example, the monomer component of the bone cement or the coating solution. The aim is to keep the amount of additional chemicals as low as possible.
[0106] The inventors have found that an amount of less than 1, preferably less than 0.2% is sufficient to stabilize nanoparticles with an average particle size between 5 and 50, preferably between 10 and 20 nm.
[0107] In this way a suspension can be prepared in which at least 90, preferably at least 99% of the silver nanoparticles are less than 50, preferably less than 20 nm.
Preferably, the nanoparticles have a substantially spherical shape, a spherical shape within the meaning of the invention as meaning a form in which the length, width and height of the particles differ by less than 20%, thus not e.g. needle-shaped particles .
In particular, with a proportion of silver nanoparticles between 0.5 and 5, preferably between 1 and 3, percent by weight in the polymer, polymer-based bone cements or cements can be prepared which have an antimicrobial effect and in which the use of antibiotics can be at least reduced or can be even completely abandon the use of antibiotics.
[0110] The present invention also includes the use of the formulations of the invention for surface treatment of implants and medical devices. The particular advantages achieved by this type of use are explained in more detail in the following examples.
[0111] The present invention in particular covers the use of the formulations according to the invention for the production of antimicrobial surfaces. The particular advantages achieved by this type of use are explained in more detail in the following examples.
[0112] The present invention also includes the use of the formulations according to the invention in silicones as coating material. The particular advantages achieved by this type of use are explained in more detail in the following examples.
[0113] The present invention also includes the use of the formulations according to the invention in thermoplastics, preferably polypropylene. The particular advantages achieved by this type of use are explained in more detail in the following examples.
[0114] The present invention also covers the use of the formulations according to the invention in thermosets, preferably the use for the production of PMMA bone cement. The particular advantages achieved by this type of use are explained in more detail in the following examples.
[0115] The present invention also includes the use of the formulations according to the invention for the production of PMMA coatings. The particular advantages of this type of use will be explained in more detail in the following examples.
Brief description of the drawings
[0116] Examples are given below to illustrate the invention and to emphasize its advantages.
[0117] Such embodiments are to be explained in more detail with reference to the drawings. It is clear that such information should not limit the invention. The drawings show
Fig. 1 UV-Vis spectrum of the aqueous solution with a 5000-fold dilution of the formulation according to the invention;
Fig. 2 measured particle sizes and calculated scanning electron microscope (SEM) record curve.
Fig. 3 transmission electron microscope (TEM) analysis of silver nanoparticles.
Fig. 4 a transmission electron microscope (TEM) photograph of an aqueous solution of a 5000-fold dilution of the formulation according to the invention;
Fig. 6 a transmission electron microscope (TEM) photograph of the coated non-woven / film laminate;
Fig. 7 the kinetics of the destruction of bacteria applied to the coated non-woven fabric, Fig. 6 (E. coli},
Fig. 8 a Transmission Electron Microscope (TEM) photograph of a polyester masterbatch with 6500 mg / kg of silver;
Fig. 9 PET / PA microfiber bands at 200 mg / kg
Fig. 10 leaching behavior and antimicrobial activity of various polyester microfibers.
[0118] The following examples are not of the invention.
Example 1:
Formulation of nanosilver with hydrazine hydrate, ammonia, Tagat TO F ™ and Tween20
[0119] 7.000 g of silver nitrate, 1.760 g of Tagat TO V ™, 1.760 Tween20 ™ and 512 g of hydrazine hydrate are prepared in 28,439 g of deionized water. The solution is stirred for 3 hours. Then 5,000 g of ammonia solution (14%) are continuously added dropwise over a 24 hour period. The reaction is complete when the addition is complete and provides a 10 wt% slurry. silver content. Particle size and distribution are determined by the UV-Vis spectrum (Figure 1). The result is a 10% nanosilver suspension with a nanosilver particle size of 1-30 nm.
[0120] The absorption spectrum is run on a 5,000-fold dilution aqueous solution that contains 20 ppm nanosilver, is clear and colored with an intense yellow color. The UV-Vis spectrum is recorded in the wavelength range from 750 to 350 nm. The measured absorption values provide a peak with a maximum at 410-420 nm and a peak half-width of about 80 nm.
[0121] The dispersing properties of the obtained 10% suspension are excellent in both polar and non-polar solvents, i.e. without further chemical (dispersing aids) or mechanical (ultrasound, Ultraturax etc.) expenditure an absolutely clear solution is obtained which has the coloration caused solely by the silver plasmon effect.
[0122] Figure 4 shows a Transmission Electron Microscope (TEM) photo of the diluted suspension of Example 1. The dark areas in Figure 4 represent nanosilver particles having a particle size of 1-30 nm.
Example 2:
Formulation of nanosilver with hydrazine hydrate, ammonia, Tagat TO P ™
[0123] 7.000 g of silver nitrate, 3.520 g of Tagat TO V ™ and 1.331 g of hydrazine sulfate are prepared in 27.620 g of deionized water. The solution is stirred for 3 hours. Then 5,000 g of ammonia solution (14%) are continuously added dropwise over a 24 hour period. The reaction is complete when the addition is complete and yields a 10 wt% slurry. silver content. Particle size and distribution are determined using the UV-Vis spectrum. The result is a 10% nanosilver suspension with a nanosilver particle size of 1-30 nm.
Example 3:
Nanosilver formulation with hydrazine sulfate, potassium bicarbonate, Tagat TO P ™ and Tween80 ™
[0124] 7.000 g of silver nitrate, 2.360 g of Tagat TO V ™, 1.160 g of Tween80 ™ and 1.331 g of hydrazine sulfate are prepared in 27.620 g of deionized water. The solution is stirred for 3 hours. Subsequently, 5,000 g of a potassium hydrogen carbonate solution (1,900 g KHCO3) are continuously added dropwise over a period of 30 hours. The reaction is complete when the addition is complete and yields a 10 wt% slurry. silver content. Particle size and distribution are determined by the UV-Vis spectrum (Figure 1). As a result, a 10% nanosilver suspension with a nanosilver particle size of 1-30 nm is obtained.
Example 4:
Formulation of nanosilver with glucose, sodium hydroxide, Tagat L2 ™ and Tween20 ™
[0125] 7.000 g of silver nitrate, 2.360 g of Tagat L2 ™, 1.160 g of Tween20 ™ and 3.708 g of glucose are prepared in 25.243 g of deionized water. The solution is stirred for 3 hours. Then 5,000 g of sodium hydroxide solution (760 g of NaOH) are continuously added dropwise over a period of 30 hours. The reaction is complete when the addition is complete and provides a 10 wt% slurry. silver content. Particle size and distribution are determined using the UV-Vis spectrum. The result is a 10% nanosilver suspension with a nanosilver particle size of 1-30 nm.
Example 5:
Nano copper formulation with hydrazine hydrate, ammonia, Tagat TO V ™ and Tween20 ™
[0126] 10.000 g copper (II) nitrate, 1.760 g Tagat TO V ™, 1.760 g Tween20 ™ and 1.090 g hydrazine hydrate are prepared in 14.260 g deionized water. The solution is stirred for 3 hours. Subsequently, 5,000 g of ammonia solution (14%) are continuously added dropwise over the course of 24 hours. The reaction is complete when the addition is complete and yields a 10 wt% slurry. copper content.
Example 6:
Further processing of the suspension of example 1 to prepare a liquid, anhydrous and salt-free formulation with silver nanoparticles
[0127] The aqueous slurry containing nanoparticles of silver obtained in Example 1 is contaminated with the by-product of ammonium nitrate. Silver nanoparticles have a particle size of 1-20 nm and are chemically stabilized. The silver content is 25% by weight. The water content is 366 g and the ammonium nitrate content is 185 g. From this suspension, 1,000 g are transferred to a beaker and heated to 45 ° C with stirring. The splitting of the slurry into two phases initiates the addition of 78 g of potassium nitrate. After the addition is complete and the potassium nitrate has completely dissolved, the heat is removed and the stirrer is turned off. The phase division can be observed after cooling. The upper, clear aqueous phase 1 is completely decanted. The remaining phase 2 has a dark brown color with a syrup-like flow and a weight of 449 g. The stable suspension is then ready to be incorporated into any organic solvent, in particular methyl methacrylate.
[0128] Analysis of the aqueous phase 1 gives a salt content of 263 g and a water content of 366 g.
[0129] Analysis of the phase 2 containing silver gives the following data:
a) analysis of the total silver content by ashing at 800 ° C yields 250 g of silver. With regard to the total formulation, this corresponds to a silver content of 56% by weight.
b) the analysis of the particle size distribution of the obtained silver is shown in figure 1. The determination is made by measuring the UV-Vis absorption spectrum in the wavelength range from 700 nm - 350 nm. The peak maximum at 415 nm corresponds to a particle size of 10 nm. The peak half width of 80 nm maximum is a measure for the narrow particle size distribution. Correlation with the SEM (Scanning Electron Microscope) and TEM (Transmission Electron Microscope) analyzes, as shown in Figure 2 and Figure 3, gives a particle size distribution of D 100 <20 nm (100% of the particle diameters are less than 20 nm).
Example 7:
Further processing of the suspension of example 1 to prepare a liquid, anhydrous and salt-free formulation with silver nanoparticles
[0130] The aqueous suspension containing nanoparticles of silver obtained in Example 1 is contaminated with the by-product of ammonium nitrate. Silver nanoparticles have a particle size of 1-20 nm and are chemically stabilized. The silver content is 10% by weight. The water content is 746 g and the ammonium nitrate content is 74 g. The division of the slurry into two phases is initiated by the addition of 202 g of potassium nitrate. After the addition is complete and the potassium nitrate has completely dissolved, the heat is removed and the stirrer is turned off. The phase division can be observed after cooling. The upper, clear aqueous phase 1 is completely decanted. The remaining phase 2 has a dark brown color with a syrup-like flow and a weight of 180 g. The stable suspension is then ready for incorporation into any organic solvent, in particular methyl methacrylate.
[0131] Analysis of the aqueous phase 1 gives a salt content of 276 g and a water content of 746 g. Analysis of the silver-containing phase 2 gives the following data:
a) analysis of the total silver content by ashing at 800 ° C yields 100 g of silver. For the entire formulation, this corresponds to a silver content of 55% by weight. b) the analysis of the particle size distribution of the obtained silver is shown in figure 1. The determination is made by measuring the UV-Vis absorption spectrum in the wavelength range from 700 nm - 350 nm. The peak maximum at 415 nm corresponds to a particle size of 10 nm. The peak half width of 80 nm maximum is a measure for the narrow particle size distribution. Correlation with the SEM (Scanning Electron Microscope) and TEM (Transmission Electron Microscope) analyzes, as shown in Figure 2 and Figure 3, gives a particle size distribution of D 100 <20 nm (100% of the particle diameters are less than 20 nm).
Example 8:
Use of the formulations according to the invention for the surface treatment of wood
[0132] The inventive suspension of Example 1 at a concentration of 100 mg / kg (with respect to the silver content of the finished product) is introduced, as is known in the art, into commercial linseed oil. A stable nanoparticle suspension is obtained which is suitable for the surface treatment of wood.
[0133] Wood coated with enriched wood oil is resistant to many chemicals and water. In addition, the wood surfaces are protected against colonization by microorganisms, i.e. microbes deposited on the described surfaces die faster compared to surfaces with unenriched wood oil.
Example 9:
Use of the formulations according to the invention for the acceleration of plant growth
[0134] The suspension of example 1 at a concentration of preferably 1-100 pg / kg (based on the silver content of the finished product) is dispersed in water. A stable suspension of nanoparticles is obtained which can be applied to plants to accelerate growth.
[0135] The effect of the aqueous nanosilver suspension on plant growth was tested with the Scenedesmus sp algae multiplication test. The test results are shown in Figure 5. In Figure 5, the test time after the addition of nanosilver is plotted on the x-axis. The optical density (OD) of the culture at 510 nm wavelength is plotted on the ordinate axis. Cultures without the addition of nanosilver (□: 0 ppb nAg) and cultures with different nanosilver contents (0: 1 ppb, ·: 10 ppb, A: 100 ppb and: 1000 ppb) were tested for algae growth.
[0136] As can be seen from figure 5, algae without addition of silver grow exponentially in the first 42 hours of multiplication to an OD of about 2.5. Then growth stops. The OD of unenriched cultures stops at about 3. The growth curve of 1 pg / kg nanosilver enriched cultures for the first 42 hours of the test is analogous to that of the unenriched culture. While growth of the unenriched cultures between 42 hours and the end of the test at 75 hours almost stops, cultures enriched with 1 pg / g nanosilver continued their growth unhindered during this period and reached the final OD value of 4.7.
[0137] The algal cultures enriched with 10 pg / kg or 100 pg / kg show a markedly increased growth of algae compared to the unenriched cultures after 25 hours. Algae grow best with the addition of 10 ppb nanosilver. The resulting final OD value after the 75 hour trial period was 5.4. This allows to prove in this experiment that the addition of 10 pg / kg of nanosilver to Scenedesmus sp. Increases the growth by 80% compared to the unenriched algae culture after 75 hours of multiplication time. When 1000 pg / kg nanosilver is added to the culture, the silver is toxic to algae. Algae added at the beginning of the experiment die quickly.
Example 10:
Use of the formulations according to the invention for the production of antimicrobial surfaces
[0138] The suspension of example 1 in a concentration of preferably 5-50 g / kg of silver is applied by plasma electrolytic oxidation to metal surfaces, such as e.g. titanium. The surfaces of strong antimicrobial activity (R value> 3) are obtained.
Example 11:
Use of the formulation according to the invention for the production of coatings for nonwoven / film laminates
[0139] The nanosilver suspension of the example is introduced at a concentration of 150 mg / kg (based on the silver content of the coating) as is known in the art to a commercially available fluoropolymer suspension for film coating. A stable, slightly yellow-colored suspension of nanosilver particles and fluoropolymer particles is obtained. Such a coating is applied with a rake to a polypropylene webbing / film laminate and thermally dried / set / cross-linked.
[0140] Figure 6 is a TEM photo of a nanosilver coating. Silver nanoparticles with a typical size of 20 nm (black points in the TEM photo) are disaggregated and very evenly distributed in the polymer coating.
[0141] Figure 7 shows the lethality kinetics (E. coli) that were applied to a coated nonwoven / film laminate. After 3.5 hours, 90% of the applied microorganisms were destroyed.
[0142] Table 1 shows the JIS 2801 microbiological test result for the described nonwoven / film laminate. During the test, 2 * 10 are placed each time<sup>5 </sup>bacteria on a nanosilver coated nonwoven / film laminate, on an uncoated nonwoven / film laminate and on a standard polystyrene surface. After 18 hours of multiplication, the number of living microorganisms is determined. In summary, it can be stated that the number of microorganisms on the nanosilver coated nonwoven / film laminate compared to standard polystyrene is reduced by 99.8%, while the uncoated nonwoven / film laminate within the biological fluctuation range does not show any reduction of microorganisms. Thus, the nanosilver coated nonwoven / film laminate 5 is considered to be highly antimicrobial effective.
[0143] Table 2 shows the result of the determination of the antifungal activity of the nanosilver coated nonwoven / film laminate. In summary, it can be stated that the nanosilver coated nonwoven / film laminate shows significant activity against the tested fungi.
Table 1: JIS 2801 microbial test for 150ppm nanosilver coated nonwoven / film laminate
1. Result of the test
Number of bacteria
After 0 h the mean value [cfu]
Inoculum 2.1 χ 10<sup>5</sup>
Number of bacteria
After 18 h the mean value [cfu] F value internal standard (polystyrene) 2.1 χ 10<sup>6</sup> 1,12
2-fold determination of independent samples
<td>After 18 h</td><td>Number of bacteria % reduction R value</td>
<td>non-woven / foil laminate with nanosilver coating</td><td>mean value [cfu]<sub>Q</sub> 99.8% 2.74 5.1 χ 10<sup>3</sup></td>
<td>non-woven / film laminate without nanosilver coating</td><td>1.8 χ 10<sup>6</sup> 35,6% 0,19</td>
<td>2. Method:</td><td>JIS Japanese Industrial Standard JIS Z 2801: 2000 Antimicrobial products - Test for antimicrobial activity and efficacy. - Plata Count Method -</td>
<td>Test bacteria:</td><td>Escherichia Coli K12</td>
<td>Modification:</td><td>Sample size: 25mm χ 25mm Calculation: R value only Pre-incubation C: LB Broth Pre-incubation D: LB Broth Inoculation medium: 1/500 dil. LB Broth (+ 0.13% Tween 80)</td>
Incubation: 37 ° C. Preparation of samples: sterilized by UVC <sup>υ</sup> % reduction and R-value against internal standard
Silver in the shell.
Table 2: Determination of the antifungal activity of a nanosilver coated nonwoven / film laminate with 150ppm silver in the coating.
<td colspan="3">1. Test result</td>
<td>Control</td><td>Mushroom growth</td><td>Corner.</td>
<td>Growth control</td><td>powerful</td><td> 6</td>
<td>Control, sterility</td><td>no</td><td></td>
<td>Samples</td><td>Antifungal activity</td><td>Corner.</td>
<td>Cotton (internal standard)</td><td>no</td><td> 6</td>
<td>Non-woven-foil laminate with coating</td><td>nanosilver - significant</td><td> 3</td>
SN 195921 - Textile Fabric - Determination of the
<td>2. Test method</td><td>Antimycotic Activity - modified</td>
<td>Test strains:</td><td>DSM 40464 - Streptomyces abikoensis DSM 9122 - Scopulariopsis brevicaulis DSM 62413 - Fusarium solani DSM 10640 - Penicillium funiculosum DSM 2404 -Aureobasidium pullulans</td>
<td>Modification:</td><td>Sample Size: 30mm 0 Pre-incubation: Potato Dextrose Agar Suspension medium: Potato Dextrose Bouillon Sample inoculation: spraying Incubation: 25 ° C, humid chamber Incubation time: 40 days Sample sterilization: UVC</td>
<td>Example 12:</td><td></td>
Use of the formulation according to the invention for the production of laminate coatings for textile decorative materials
[0144] The nanosilver suspension of example 1 is introduced at concentrations of 100 mg / kg and 200 mg / kg (based on the silver content of the coating) with prior art agents into a commercially available fluoro polymer suspension for textile coating. A stable, slightly yellow-colored suspension of nanosilver particles and fluoropolymer particles is obtained. Such a coating is applied to a decorative textile and thermally dried / set / cross-linked.
[0145] Table 3 shows the results of microbiological tests on decorative wiper textiles with 2 different hydrophobic water-based coatings and two dosages of nanosilver each in accordance with JIS 1902. Hydrophobic water-based coatings AG4 and AG8 are commercially available fluoropolymer coatings. With the coating AG4, a strong reduction of the microorganisms in each case is observed with the addition of nanosilver 100 mg / kg or 200 mg / kg in relation to the untreated textile material. With the AG8 coating, the addition of 100 mg / kg nanosilver is not sufficient to hinder the growth of microorganisms. On the other hand, the addition of 200 mg / kg causes a strong reduction of microorganisms in relation to the untreated fabric.
Table 3: Microbiological tests according to JIS 1902 on decorative wiper textiles with 2 different hydrophobic water-repellent coatings and two doses of nanosilver each time.
1. Result of the test
Number of bacteria
After Oh, mean value [cfu]
<td>Inoculum</td><td colspan="3">1.8 χ 10<sup>5</sup></td>
<td>After 18 h A0 fibers (uncoated)</td><td colspan="2">Number of bacteria, mean value [cfu] 1.5 χ 10<sup>7</sup></td><td>Value F. 1.92</td>
<td colspan="2">2-fold determination of independent samples</td><td></td><td></td>
<td>After 18 h</td><td>Number of bacteria</td><td>% reduction<sup>1</sup></td><td>Value</td>
<td></td><td>mean value [cfu]</td><td></td><td>R</td>
<td>Control: 080116-xhf01 Mesh fabric</td><td>160 / 200F <1.0 χ 10<sup>2</sup></td><td> 99,9993%</td><td> 5,18</td>
<td>(Rita), DTY Decorative doormat material AG4 100 ppm coating</td><td>1.4 χ 10<sup>4</sup></td><td> 99,9%</td><td> 3,03</td>
<td>Decorative doormat material AG4 coating 200 ppm</td><td>2.4 χ 10<sup>5</sup></td><td> 98,4%</td><td> 1,79</td>
<td>Decorative doormat material</td><td>4.6 χ 10<sup>7</sup></td><td>Well</td><td> -0,49</td>
AG8 coating 100 ppm
Decorative doormat 7.8 <sup>χ</sup> 10<sup>3</sup> 99,9% 3,29
AG8 coating 200 ppm
<td>2. Test method:</td><td>JIS Japanese Industrial Standard JIS L 1902: 2002 "Testing for antibacterial activity and efficacy on textile products". - Plata Count Method -</td>
<td>Test strain:</td><td>Escherichia Coli K12</td>
<td>Modification:</td><td>Weight: 0.4 g Calculation: R value only Pre-incubation C: LB Broth Pre-incubation D: LB Broth Inoculation medium: Phosphate Buffered Saline with 0.05% Tween 80 Incubation: 37 ° C</td>
<sup>υ</sup> % reduction and R value based on the uncovered
Example 13:
Use of the formulations according to the invention in varnishes and adhesives
[0146] The nanosilver suspension of example 1 is introduced at a concentration of 270 mg / kg (based on the silver content of the finished product) as is known in the art for commercially available lacquers suitable for lacquering wood (in particular for finishing stairs and parquet) . Stable suspensions with free nanosilver particles are obtained.
Table 4 shows the results of the microbiological tests for water-based and solvent-based varnishes with 270 ppm of nanosilver in each case. In the case of both varnishes, the addition of 270 mg / kg of nano-silver as a refining additive results in a strong reduction of microorganisms compared to the standard surface.
Table 4: Microbiological tests according to JIS 2801 for water and solvent based varnishes with 270 ppm nanosilver each (for finishing stairs and parquet).
1. Result of the test
Number of bacteria Po Oh mean value [cfu]
Inoculum 2.1 <sup>χ</sup> 10<sup>5</sup>
Pol8h Number of bacteria F value mean value [cfu] internal standard (polystyrene) 2.2 <sup>χ</sup> 10<sup>5</sup>0,02
2-fold determination of independent samples
Pol8h Number of bacteria% reduction<sup>1</sup> R value mean value [cfu]
Varnish, water-based with 270 ppm Ag 1.0 <sup>χ</sup> 10<sup>2</sup> 99,95%3,35
Varnish, solvent-based with 270 1.0 <sup>χ</sup> 10<sup>2</sup> 99.95% 3.35 ppm Ag
<td>2. Test method:</td><td>JIS Japanese Industrial Standard JIS Z 2801: 2000 Antimicrobial products - Test for antimicrobial activity and efficacy. - Plata Count Method -</td>
<td>Test strain:</td><td>Escherichia Coli K12</td>
<td>Modification:</td><td>Sample size: 25 mm <sup>x</sup> 25 mm Calculation: R value only Pre-incubation C: LB Broth Pre-incubation D: LB Broth</td>
<td colspan="2">Inoculation medium: 1/500 dil. LB Broth (+ 0.13% Tween 80) Incubation: 37 ° C</td>
Preparation of samples: sterilized by UVC
1)% reduction and R-value against internal standard
Example 14:
Use of the formulations according to the invention in silicones
[0148] The nanosilver slurry of example 1 is incorporated at typical concentrations of 100 mg / kg to 1000 mg / kg (based on the silver content of the finished product) as is known in the art to commercially available silicones. Stable suspensions with free nanosilver particles are obtained.
[0149] Table 5 shows the results of microbiological tests on 2-component silicones with different nanosilver contents according to JIS 2802. The addition of 200 mg / kg nanosilver as a performance additive results in a strong microbial reduction of 97.5% compared to the standard surface. From 500 mg / kg of nanosilver, a strong microbial reduction of 99.9% is achieved.
Table 5: JIS 2801 microbiological testing on 2-component silicones with 10 different nanosilver contents
1. Result of the test
Bacterial count average value
After 0 h [cfu]
Inoculum 1.0 χ 10<sup>5</sup>
Bacterial count average value
After 18 h [cfu] F value internal standard (polystyrene) 1.4 χ 10<sup>5</sup> 0,02
2-fold determination of independent samples
Bacterial count average value
<td>After 18 h</td><td>[chi]</td><td>% reduction <sup>1</sup></td><td>The value of R.</td>
<td>Silicone with 200 ppm Ag</td><td>3.5 χ 10<sup>3</sup></td><td> 97,5%</td><td> 1,6</td>
<td>Silicone with 500 ppm Ag</td><td><1.0 χ 10<sup>2</sup></td><td> 99,9</td><td> 3,1</td>
<td>Silicone with 1000 ppm Ag</td><td><1.0 χ 10<sup>2</sup></td><td> 99,9%</td><td> 3,1</td>
<td>2. Test method:</td><td>JIS Japanese Industrial Standard JIS Z 2801: 2000 Antimicrobial products - Test for antimicrobial activity and efficacy. - Plata Count Method -</td>
<td>Test strain:</td><td>Escherichia Coli K12</td>
<td>Modification:</td><td>Sample size: 25mm χ 25mm Calculation: R value only Pre-incubation C: LB Broth Pre-incubation D: LB Broth Inoculation medium: 1/500 dil. LB Broth (+ 0.13% Tween 80) Incubation: 37 ° C Preparation of samples: sterilized by UVC</td>
1)% reduction and R-value against internal standard
Example 15:
Use of the formulations according to the invention in polypropylene films
[0150] The nanosilver slurry of example 1 is introduced at typical concentrations from 100 mg / kg to 5000 mg / kg (based on the silver content of the finished layer) by extrusion into the layer of the multilayer propylene film. Films are obtained with a layer thickness of approximately 5 [mu] m of homogeneously distributed, predominantly isolated nanosilver particles.
[0151] Table 6 shows the results of microbiological tests on a multilayer polypropylene film with different nanosilver contents according to JIS 2801. The addition of 2100 mg / kg or 3200 mg / kg nanosilver as an additive results in a strong reduction of microorganisms of approximately 99% compared to the standard surface .
Table 6: Microbiological tests on a multilayer polypropylene film.
<td>1. Test result</td>
<td>After 0 h Number of bacteria</td>
<td>mean value [cfu]</td>
<td>1.7 χ inoculum 10<sup>5</sup></td>
<td>After 18 h Number of bacteria F value</td>
<td>mean value [cfu]</td>
<td>internal standard (polystyrene) 5.1 χ 10<sup>5</sup> 0,5</td>
<td>2-fold determination of independent samples</td>
<td>After 18 h Number of bacteria% reduction<sup>1</sup> The value of R.</td>
<td>mean value [cfu]</td>
<td>Control, antibacterial <1.0 χ 10<sup>2</sup> >99,98% >3,7</td>
<td>Film with 2100 ppm Ag on page 5.8 χ 10<sup>3</sup> 98,87% 1,9</td>
<td>internal</td>
<td>Film with 3200 ppm Ag on page 6.9 χ 10<sup>3</sup> 98,66% 1,9</td>
<td>internal</td>
<td><sup>υ</sup> % reduction and R-value against internal standard</td>
<td>2. Test method: JIS Japanese Industrial Standard JIS Z 2801: 2000</td>
<td>Antimicrobial products - Test for antimicrobial activity and</td>
<td>efficacy.</td>
- Platy Count Method Test strain:
Escherichia Coli K12
<td>Modification:</td><td>Sample size: 30mm χ 40mm Calculation: R value only Pre-incubation: Medium LB Inoculation medium: 1/500 dil. LB Broth (+ 0.13% Tween 80) Incubation: 37 ° C Preparation of samples: no</td>
Example 16:
Use of the formulation according to the invention in polypropylene wash tubs
[0152] The nanosilver suspension of example 1 is introduced at a concentration of 6500 mg / (based on the silver content) by extrusion into polypropylene. A masterbatch is thus obtained with nanosilver particles which are predominantly present in the isolation from one another. The nanosilver masterbatch is introduced at typical concentrations from 100 mg / kg to 5000 mg / kg (based on the silver content of the finished polymer) into a polypropylene wash bath container. Washing bath containers are intended for placing and temporary storage of used washing bath or rinsing solutions from dishwashing processes or washing textiles. The addition of nanosilver as an enriching additive is to prevent the colonization of the polymer by microorganisms.
[0153] Table 7 shows the results of microbiological tests on JIS 2801 polypropylene wash tubs with different nanosilver contents. The addition of 520 mg / kg or 1000 mg / kg or 2000 mg / kg of nanosilver as an enriching additive each time causes a strong reduction of microorganisms over 99.99% compared to the standard surface.
Table 7: Microbiological Tests on Polypropylene Wash Tubs in accordance with JIS 2801
1. Result of the test
<td>After Oh Inoculum</td><td colspan="3">Number of bacteria mean value [cfu] 3.6 χ 10<sup>5</sup></td>
<td>After 18 h</td><td colspan="2">Number of bacteria mean value [cfu]</td><td>The value of F</td>
<td>internal standard (polystyrene)</td><td>1.1 χ 10<sup>6</sup></td><td></td><td> 0,5</td>
<td>2-fold determination of independent samples After 18 h Control, antibacterial</td><td>Number of bacteria mean value [cfu] <1.0 χ 10<sup>2</sup></td><td>% reduction<sup>1</sup> >99,99%</td><td>The value of R. > 4.0</td>
<td>3-fold determination of independent samples Container for washing bath with 520 ppm Ag</td><td><1.0 χ 10<sup>2</sup></td><td> >99,99%</td><td> >4,0</td>
<td>Washing bath container with 1000 ppm</td><td><1.0 χ 10<sup>2</sup></td><td> >99,99%</td><td> >4,0</td>
<td>Ag Washing bath container with 2000 ppm</td><td><1.0 χ 10<sup>2</sup></td><td> >99,99%</td><td> >4,0</td>
Ag
<td>2. Test method:</td><td>JIS Japanese Industrial Standard JIS Z 2801: 2000 Antimicrobial products - Test for antimicrobial activity and efficacy. - Plata Count Method -</td>
<td>Test strain:</td><td>Escherichia Coli K12</td>
<td>Modification:</td><td>Sample size: 30mm χ 40mm Calculation: R value only Pre-incubation: Medium LB Inoculation medium: 1/500 dil. LB Broth (+ 0.13% Tween 80) Incubation: 37 ° C Preparation of samples: no</td>
1)% reduction and R-value against internal standard
Example 17:
Application of the formulation according to the invention in Wood Plastic Composites (WPC)
[0154] The nanosilver suspension of example 1 is admixed during the extrusion of PVC and wood flour at a concentration of 50 mg / kg to 1000 mg / kg. WPC materials resistant to weather conditions and rot are obtained.
Example 18:
Use of the formulations according to the invention in polyolefin elements
[0155] The nanosilver suspension of example 1 is mixed with white oil with polyolefin polymer beads (PE or PP), resulting in a silver concentration of 50 mg / kg to 500 mg / kg in the finished mixture. The mixture is pressed into molded elements (e.g. cutting boards, filters, cosmetics applicators) and mechanically processed. The resulting cutting boards have an antimicrobial activity with an R value between 1 and 4, depending on the silver content.
Example 19:
The use of the formulation according to the invention for the production of PVC plastisol coated textiles
[0156] The nanosilver suspension of example 1 is introduced at typical concentrations of 400 mg / kg (based on the silver content of the finished polymer) into the PVC plastisol. Plastisol is used to coat textile knitted fabrics. The result is mats which, for example, can be used as a floor covering in wet rooms, as a gymnastic mat, as a carpet stopper or also as a dish dryer. The addition of nanosilver as an enriching additive is to prevent the colonization of the polymer by microorganisms.
Table 8 shows the results of microbiological tests on polypropylene containers for washing baths with the addition of 400 mg / kg of nanosilver as an enriching additive. The addition of 400 mg / kg of nanosilver as an enriching additive results in a significant antifungal activity against the 5 tested fungi.
Table 8: Test for antifungal activity of PVC plastisol with silver content
400 ppm.
<td>1. Test result</td><td></td><td></td>
<td>Control</td><td>Mushroom growth</td><td>Corner.</td>
<td>Cotton (internal standard)</td><td>powerful</td><td> 6</td>
<td>Growth control</td><td>strong</td><td> 6</td>
<td>Control, sterility</td><td>no</td><td></td>
<td>A sample</td><td>Antifungal activity</td><td>Corner.</td>
<td>PVC plastisol was washed</td><td>significant</td><td> 5</td>
<td>Plastisol PVC untreated, 15 χ with 400 ppm Ag, 15 <sup>x</sup> washed</td><td>no</td><td> 3</td>
<td>2. Test method</td><td>SN 195921 - Textile Fabric - Determination of the Antimycotic Activity - modified</td>
<td>Test strains:</td><td>DSM 40464 - Streptomyces abikoensis DSM 9122 - Scopulariopsis brevicaulis DSM 62413 - Fusarium solani DSM 10640 - Penicillium funiculosum DSM 2404 - Aureobasidium pullulans</td>
<td>Modification:</td><td>Sample Size: 30mm 0 Pre-incubation: Potato Dextrose Agar Suspension medium: Potato Dextrose Bouillon Sample inoculation: spraying Incubation: 25 ° C Incubation time: 41 days Sample sterilization: UVC</td>
Example 20:
Use of the formulation according to the invention in PMMA bone cement
[0157] The nanosilver suspension of Example 1 is introduced at typical concentrations from
100 mg / kg to 5000 mg / kg (based on the silver content of the finished product) with prior art agents for commercially available PMMA bone cements. The incorporation may be either in dry PMMA powder or in liquid MMA monomer. After hardening, bone cements are obtained with homogeneously separated, mostly isolated nanosilver particles. [0158] Table 9 shows the results of the various leaching tests.
Thus, Table 9 shows that a sample equipped with 2149 mg / kg bone cement when eluted with 10 ml SimulatedBodyFluid (SBF) at the elution temperature of 37 ° C within 12 days will lose 4 ng of silver per mm of surface into the solution. The row below in Table 9 shows that a slight increase in the nanosilver content in the sample to 2500 mg / kg and the reduction of the elution time to 5 days does not cause a major change in the eluted amount of silver. During the aging test, an amount of 13 ng / mm was eluted by boiling the sample in SBF. With a daily replacement of the leaching fluid, an equilibrium of 1.2 ng / mm and day is established.
Table 9: Acrylate bone cement (PMMA) with 2500 ppm Ag.
<td></td><td>nAg content in the sample</td><td>Leaching volume</td><td>Temp. leaching</td><td>Washout time</td><td>Washed amount of silver</td>
<td>Release kinetics</td><td>2149 ppm</td><td>10 mL SBFm</td><td>37 ° C</td><td>12 d</td><td>4 ng / mm<sup>2</sup> (0.4 ng / g-mm<sup>2</sup>)</td>
<td>Variation in silver content</td><td>2500 ppm</td><td>10 mL SBFm</td><td>37 ° C</td><td>5d</td><td>4 ng / mm<sup>2</sup> (0.4 ng / g-mm<sup>2</sup>)</td>
Example 21:
Use of the formulations according to the invention for the production of PMMA coatings
[0159] The nanosilver slurry of example 1 is incorporated at typical concentrations of 100 mg / kg to 5000 mg / kg (based on the silver content of the finished product) as is known in the art for commercially available PMMA formulations. The incorporation may be either in dry PMMA powder or in liquid MMA monomer. Mixed formulations are mainly used to coat medical products. After hardening, PMMA coatings with homogeneously separated, mostly isolated nanosilver particles are obtained.
Example 22:
Use of the formulations according to the invention for the production of synthetic fibers
[0160] The nanosilver suspension of example 1 is introduced in typical concentrations from 1000 mg / kg to 20,000 mg / kg (based on the silver content) by extrusion into commercially available thermoplastics such as e.g. polypropylene, polyester, polyamide. In this process, masterbatches with predominantly nanosilver particles are isolated from each other.
[0161] Figure 8 shows an example of a Transmission Electron Microscope (TEM) photograph of a polyester masterbatch with 6500 mg / kg of silver. The dark spots in figure 8 show the uniform distribution and poor agglomeration of the nanosilver particles in the polyester.
[0162] Prior art masterbatches are used diluted in the production of synthetic fibers, e.g. from polypropylene, polyester or polyamide.
[0163] Figure 9 shows more PET / PA microfiber bands with 200 mg / kg nanosilver. In figure 9, individual nanosilver particles (bright spots) can be clearly identified in the segmented yarns. Typical silver contents for antimicrobial effects are in the range from 100 mg / kg to 300 mg / kg.
[0164] In addition to microfibers, monofilaments and bicomponent fibers for clothing, bed fillings, drapes and technical textiles as well as non-woven materials are also produced. Silver-containing synthetic fibers can also be used in the form of staple fibers to reinforce other fibers (including natural fibers such as cotton). The silver content used in accordance with the dilution by other fibers is at a high level compared to the direct equipment of synthetic fibers.
[0165] Figure 10 shows the leaching behavior (A) and the antimicrobial activity () of various polyester microfibers. The silver content of the various fibers ranges from 150 mg / kg to up to 195 mg / kg. The fibers were washed in water for 3 hours each time. The eluted silver content is in the range of 120 pg / kg to 200 pg / kg water, the antimicrobial inhibitory effect is in each case above 96%. Table 10 shows the results of the JIS 1902 antimicrobial tests of such microfibers.
Example 23:
Preparation of a stable suspension of silver nanoparticles in methyl methacrylate
[0166] The product of Example 6 or Example 7 is used to prepare the silver nanoparticle formulation in methyl methacrylate. For this purpose, 990 g of methyl methacrylate (Merck, for synthesis) are prepared in a 2 L beaker and stirred with a magnetic stirrer at room temperature. 1 g of a crosslinker (Evonic, Tego dispers 655) is added via a pipette. After adding 9.3 g of the product of Example 6, the color of the solution turned to orange-brown. By turning the beaker you can create a thin coating on the glass wall, which is light yellow in color, is clear and does not contain visible particles. 1,000 g of a suspension are obtained with a silver content of 5.115 mg / kg. The size and size distribution of the particles correspond to the representation in Figures 2 and 3.
Example 24:
Preparation of a stable suspension of silver nanoparticles in methyl methacrylate
[0167] For the preparation of silver nanoparticles in methyl methacrylate, the product of example 6 or example 7 is used. For this, 980 g of methyl methacrylate (Merck, for synthesis) is prepared in a 2 L beaker and stirred with a magnetic stirrer at room temperature. 2 g of a crosslinking agent (Evonic, Tego dispers 655) is added via a pipette. After 18.2 g of the product of Example 6 had been added, the color of the solution turned to orange-brown. By turning the beaker you can create a thin coating on the glass wall, which is light yellow in color, is clear and does not contain visible particles. 1,000 g of a suspension are obtained with a silver content of 10,010 mg / kg. The size and size distribution of the particles correspond to the representation in Figures 2 and 3.
Example 25:
Preparation of a stable suspension of silver nanoparticles in methyl methacrylate
[0168] The product of Example 6 or Example 7 is used to prepare the silver nanoparticle formulation in methyl methacrylate. For this purpose, 897 g of methyl methacrylate (Merck, for synthesis) are prepared in a 2 L beaker and stirred with a magnetic stirrer at room temperature. 10 g of crosslinker (Evonic, Tego dispers 655) are added via a pipette. After adding 92.7 g of the product of Example 6, the color of the solution turned to orange-brown. By turning the beaker you can create a thin coating on the glass wall, which is light yellow in color, is clear and does not contain visible particles. 1,000 g of a suspension are obtained with a silver content of 50,985 mg / kg. The size and size distribution of the particles correspond to the representation in Figures 2 and 3.
Example 26:
Production of an antibacterial carrier material based on PMMA
[0169] The product of example 1 is incorporated in a concentration of 100 mg / kg to 10,000 mg / kg, each time based on the finished product, into the pearlescent PMMA polymer. Preferably, the incorporation is into dry PMMA powder. Furthermore, substances having a pharmaceutical effect, such as gentamicin, as well as other additives, such as, for example, zirconium oxide as X-ray contrast agents, can also be added to the PMMA powder.
[0170] The PMMA powder is produced by injection molding into spheres having an antimicrobial effect, for example with a diameter between 5 and 10 mm and a weight of between 100 and 300 mg. Due to the resistance of the nanosilver suspension to high temperatures, up to 240 ° C, it is easily possible. A 200 mg bead may, for example, contain 4.5 g gentamicin and 20 mg zirconium oxide.
[0171] The beads can also be anchored to a multifilament surgical wire.
20 sheets
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12 members in 6 offices
Priority claims8
| Document | Office | Kind | Date |
|---|---|---|---|
| 2010075165 | Germany | W | |
| 11758380 | European Patent Office (EPO) | A | |
| 2011004211 | European Patent Office (EPO) | W | |
| 117583807 | – | – | – |
| EP20110758380 | – | – | – |
| PCTDE2010075165 | – | – | – |
| WO2010DE75165 | – | – | – |
| WO2011EP04211 | – | – | – |
Members12
| Document | Office | Kind | |
|---|---|---|---|
| DE102009059276A1 | Germany | A1 | |
| WO2011076203A1 | World Intellectual Property Organization (WIPO) | A1 | |
| WO2012084072A1 | World Intellectual Property Organization (WIPO) | A1 | |
| EP2515660A1 | European Patent Office (EPO) | A1 | |
| EP2654429A1 | European Patent Office (EPO) | A1 | |
| EP2515660B1 | European Patent Office (EPO) | B1 | |
| US2015190550A1 | United States of America | A1 | |
| US2018055975A1 | United States of America | A1 | |
| EP2654429B1 | European Patent Office (EPO) | B1 | |
| TR2018015494T4 | Türkiye | T4 | |
| TR201815494T4 | Türkiye | T4 | |
| PL2654429T3This record | Poland | T3 |
Numbers
- Publication
- 2654429
- Publication, DOCDB
- 2654429
- Publication, EPODOC
- PL2654429T
- Application
- 11758380
- Application, DOCDB
- 11758380
- Application, EPODOC
- PL19800117583T
Titles2
- English
- PROCESS FOR PREPARING A SILVER NANOPARTICLES CONTAINING DISPERSION AND USE OF SILVER NANOPARTICLES CONTAINING MIXTURE AS COATING
- Polish
- Sposób wytwarzania zawiesiny zawierającej nanocząstki srebra oraz zastosowanie mieszaniny zawierającej nanocząstki srebra jako środka powlekającego
Classification
- CPC, 7
- A61L24/0015
- A01N59/16
- A61L24/0089
- A61L27/34
- A61L27/54
- A61L2300/104
- A61L2300/606
