Process for encapsulating particles and the encapsulated product of that process
10 claims: 7 independent, 3 dependent
- 1Patentkrav 1. Innkapslet, aktivt halogenblekemlddel, karakterisert ved at det omfatter:(i) 30 til 95 vekt-$ aktiv halogenblekemiddelkjerne;(ii) 2 til 40 vekt-$ av et første beleggsmateriale;og (ill) 2 til 30 vekt-$ av et andre beleggsmateriale med et smeltepunkt høyere enn det til det første beleggsmaterlalet.
- 2Fremgangsmåte for fremstilling av et innkapslet, aktivt halogenblekemlddel ifølge krav 1, ved innkapsling av en reaktlv kjernepartikkel for å beskytte partikkelen fra nedbrytende interaksjon ved kontakt med reaktive forbindelser, ved å forbedre lnnkapslingseffektivlteten, karakterisert ved at den omfatter:a) å bringe kjernepartlkkelen i kontakt med en tilstrekkelig mengde av et første beleggsmateriale for å danne et enkelt belegg for kjernepartlkkelen;b) å bringe den enkeltbelagte partikkel i kontakt med et andre beleggsmateriale der dette har et smeltepunkt over det til det første, for derved å danne en belagt partikkel med minst to beleggssjikt;c) oppvarming av den belagte partikkel til en temperatur over smeltepunktet for det første belegg men under smeltepunktet til det andre for å danne et flytende første beleggssjikt;og d) å la det flytende første belegg størkne.
- 3Fremgangsmåte ifølge krav 2 for innkapsling av en reaktlv kjernepartikkel i et hvirvelsjikt for å beskytte partikkelen fra nedbrytende interaksjon ved kontakt med reaktive forbindelser ved forbedring av lnnkapslingseffektivlteten, karakt er lsert ved at den omfatter:a) å fluidlsere et antall av partiklene i et hvlrvelsjikt;b) å bringe partiklene i kontakt med et vanligvis fast belegningsmateriale ved en effektiv temperatur for å bevirke et smeltet, flytende belegg for derved å tildanne partikler med et første belegg;c) å bringe partiklene med et første belegg 1 kontakt med et vanligvis fast beleggsmaterlale ved en effektiv temperatur for å bevirke et smeltet, flytende belegg for derved å danne partikler med minst et første og et andre belegg idet det andre belegg har et smeltepunkt over det til det første beleggsmaterlale ;d) å oppvarme partiklene med minst ett første og andre belegg til en temperatur over smeltepunktet for det første belegg, men under smeltepunktet til det andre for derved å danne et generelt sfærisk, flytende sjikt mellom kjernen og det andre belegg;og e) å la det sfæriske, flytende belegg størkne.
- 4Fremgangsmåte Ifølge krav 2 og 3, karakterisert ved at man benytter partikler med en partikkelstørrelse på 2 til 250 mm.
- 5Fremgangsmåte ifølge kravene 2-4, karakterisert ved at man som første beleggsmaterlale benytter en i det vesentlige vannuoppløselig forbindelse.
- 6Fremgangsmåte ifølge kravene 2-5, karakterisert ved at man som første beleggsmaterlale velger et fra gruppen Ci’2-20“^ e ^1 ;s y rer eller mikrokrystallinsk voks og blandinger derav.
- 7Fremgangsmåte ifølge kravene 2-6, karakterisert ved at partiklene før kontakt med det første beleggs166290 materiale bringes 1 kontakt med et forbeleggsmateriale med et smeltepunkt over den temperatur som oppnås 1 trinn (c) (krav 2) henholdsvis (d) (krav J) for å forhindre kjemisk Interaksjon mellom partiklene og det første beleggsmateriale.
- 8Fremgangsmåte ifølge kravene 2-7, karakterisert ved at forbeleggs-materialet velges blant alkalimetallsulfater, alkalimetallfosfater og blandinger derav.
- 9Fremgangsmåte ifølge kravene 2-8, karakterisert ved at minst ett av beleggene bringes i kontakt i en vandig oppløsning og tørkes før kontakt med et efterfølgende belegg.
- 10Fremgangsmåte ifølge krav 2 for innkapsling av partikler i et hvirvelsjikt, karakterisert ved at den omfatter:a) fluldiserlng av ca. 2 til 250 mm faste aktive halogenblekemiddelpartikler i et hvirvelsjikt;b) å justere temperaturen 1 hvirvelsjiktet til fluidiseringstemperaturen for et forbeleggsmateriale;c) å bringe partiklene 1 kontakt med en oppslemmlng eller en oppløsning av et vanligvis fast forbeleggsmateriale inntil 1 det vesentlige alle partikler er belagt med forbeleggsmaterialer for å danne partikler med et forbelegg, idet forbeleggsmaterialet er valgt blant alkalimetallsulfater, alkalimetallfosfater og blandinger derav;d) å bringe forbelegget til størkning;e) å besprøyte partiklene med et forbelegg, med en smelte, oppslemmlng eller oppløsning av et vanligvis fast første beleggsmateriale inn til i det vesentlige alle partikler med forbelegg er belagt med et første beleggsmateriale for å danne partikler med et forbelegg og et første belegg, idet det første beleggsmateriale er valgt blant Cig-20 fettsyrer, mikrokrystallinsk voks og blandinger derav;f) å bringe det første indre belegg til størkning;g) å besprøyte partiklene med et forbelegg og et første belegg med en oppslemming eller oppløsning av et vanligvis fast andre beleggsmateriale inntil i det vesentlige alle partikler med disse belegg er belagt med et andre beleggsmateriale, for derved å oppnå varmebehandllngsbare partikler, idet det andre beleggsmateriale har et smeltepunkt over smeltepunktet for det første beleggsmateriale og er valgt blant alkallmetallsulfater, alkallmetallfosfater og blandinger derav;h) å bringe det andre ytre belegg til størkning;i) å oppvarme de varmebehandllngsbare partikler til en temperatur mellom smeltepunktene for det første og andre belegg for å omgjøre det første beleggsmaterialet til et flytende sjikt;og j) å bringe det flytende sjikt til størkning for å danne en fast tetning.
Independent claims10
135 paragraphs in 3 sections, as filed
(74) Prosecutor Civil Service. Jan E. Helgerud, Bryns Patentkontor A / S, Oslo.
(30) Priority Requested 10.03.86, IJS, No. 838276.
(54) Designation of the Invention Encapsulated, Active Halogen Bleach1 ODEL AND MANUFACTURING THEREOF.
(57) Summary Effective encapsulation of core particles, especially halogen bleaches, is achieved by (1) Encapsulation of the particle 1 at least two separate coatings where the melting point of the inner or first coating material is below the melting point of the outer or second coating material, (11) heating it thus Encapsulated particle to a temperature between the melting points of the Inner and Outer Coatings to make the inner coating fluid, and (ill) allowing the liquid inner coating to solidify, thereby forming a continuous, non-porous lining coating.
(56) Published publications None.
The present invention relates to an encapsulated active halogen bleach component.
The invention also relates to a process for preparing such an Encapsulated Bleach by encapsulating a reactive core particle to protect the particle from degrading interaction upon contact with reactive compounds.
Encapsulation as used herein is a process in which a small, discrete unit of particulate material, usually called the core, is coated with one or more layers of a coating material to prevent premature contact between the core and the environment. The coating, or coatings, isolates the core particle for later release under controlled conditions.
Virtually any substance that can be converted into discrete particles can be encapsulated. The core material may consist of a single substance or mixture of several such, and may be solid, liquid or gaseous in nature. Core materials are typically those substances or mixtures which, if used unencapsulated, will be consumed or deactivated before they are used.
<td>has fulfilled one</td><td>intended function.</td><td>The following list</td>
<td>behave generically</td><td colspan="2">classes of substances encapsulated:</td>
<td>adhesives</td><td>bacteria</td><td>drlvmidler</td>
<td>catalysts</td><td>herdemldler</td><td>detergents</td>
<td>drugs</td><td>dyestuffs</td><td>flavorings</td>
<td>foodstuffs</td><td>fuels</td><td>printing ink</td>
<td>lnsektlcider</td><td>avspaltingsmidler</td><td>metals</td>
<td>monomers</td><td>coils</td><td>paints</td>
<td>perfumes</td><td>photographic means</td><td>pigments</td>
<td>plasticizers</td><td>drlvmidler</td><td>solvents</td>
<td>stabilizers</td><td>viruses</td><td>vitamins</td>
A wide range of coating materials have been used to encapsulate core particles. The most commonly used coating agents are natural or synthetic polymers, including, for example, gelatin, ethyl cellulose or poly (methyl
<td>methacrylate).</td><td>Typical coating agents</td><td>is:</td>
<td>gelatin</td><td>rubber</td><td>gum arabic</td>
<td>starches</td><td>sugars</td><td>ethylcellulose</td>
<td>carboxymethyl</td><td>shellac</td><td>kolofonlum</td>
<td>cellulose</td><td>paraffin</td><td>tristearln</td>
<td>polyethers</td><td>polyethylene</td><td>polypropylene</td>
<td>polybutadlen</td><td>polystyrene</td><td>polyakrylamlder</td>
<td>epoxides</td><td>polyesters</td><td>polyamides</td>
<td>aluminum</td><td>polyisoprene</td><td>slllkoner</td>
<td>copper</td><td>polyurethanes</td><td>silicates</td>
<td></td><td></td><td>silver.</td>
Great attention has been paid to coating compositions used in 1 mixed cleansers to protect each component from harmful degradation of other components. Characteristic bleaches can react with organic cleansers during manufacture and storage. Such reactions can reduce the active concentration of both bleach and detergent. In the formulation of detergents, it is also difficult to maintain an effective concentration of the bleach in the detergent mixture. Typical bleaching preparations are relatively unstable in the presence of alkaline compounds and free moisture. Known coating compositions simply do not segregate reactive compositions to prevent significant loss of bleaching and cleaning activity.
The numerous substances used as constituents of the detergent formulation can be divided into the following groups:
a) surfactants; the main detergent in detergents; b) diluents or fillers; inorganic salts, acids and bases which do not contribute to the washing process;
c) builders; additives which enhance the wash sensation, foaming, emulsifying or dirt suspending effect of the composition; and d) special purpose additives such as (1) bleaching agents, (11) brighteners, (lii) bactericides, and (lv) plasticizers.
Many attempts have been made to produce a detergent composition containing a stable bleaching component, including encapsulation of the bleaching agent. Many different coating methods and coating agents have been used in an attempt to obtain a reasonably efficiently encapsulated bleaching agent. Examples of such are disclosed in U.S. Patent No. 4,279,764, (Chemical Encapsulation of a chlorine bleach with a silicate-bonded, hydrated soluble salt containing an NH chlorine acceptor component), U.S. Pat. PS 3 908 044 and 3 908 045 (double coating vertebrate layer encapsulation of a chlorine releasing agent with a first coating of a C2-2-22 fatty acid and a second coating of a fixed alkali hydroxide).
Today's interest in the encapsulation technique is focused on the encapsulation efficiency of the process. The encapsulation efficiency is characteristically determined by measuring the percentage of nuclear material released into solution after a specified period of time when placed in a dissolving environment. Several of the proposed encapsulation processes have been able to increase encapsulation efficiency beyond what is characteristically achieved, but achieve such results only at high cost and / or a difficult process.
It is generally believed that the low encapsulation efficiency is at least mainly due to the lack of (i) complete coating of the core particle, (ii) uniform coating, and / or (iii) preventing the development of cracks, pores and scratches in the coating.
One of the main difficulties to be considered when reasonably seeking to achieve high encapsulation efficiency is that the coating must be applied in molten form. Ideally, the coating should be applied as a flowing liquid to allow it to flow around the core, sealing to the core without cracks or openings. However, if the coating is added as a flowing liquid, the coating may often fail to adhere to the core and thus leave an insufficiently coated core.
The process temperature at which the coating agent is added has been found to be critical. If the temperature is too low, the coating may contain numerous cracks and cracks which may be due to poor wetting of the core surface or an inability to coat the core and if it is too high (above the melting point of the coating agent) the coating system may cause agglomeration of the particles or cause a total collapse of fluidized particles. The encapsulation efficiency is improved when the process temperature is kept just below the melting point of the coating agent. Such critical process temperatures result in long batch cycle times and the need for critical temperature control.
In an attempt to achieve the desirable viscosity, the coating compounds are often mixed with a volatile solvent. While this often increases the coating efficiency, the use of volatile solvents is dangerous, then
1) many solvents are flammable and explosive, and
2) Many solvents are toxic by inhalation. In addition, the use of solvents is costly, since (i) the expensive solvent is typically used in large quantities and must be recovered, and (11) expensive explosion proof equipment must be used such as static electricity control systems, explosion valves, amplified equipment, solvent recovery systems and the like.
Accordingly, there is a substantial need for a simple, affordable solvent-free encapsulation process that works with a wide combination of core and coating compounds and results in a very effective encapsulation product.
According to this invention, the present invention relates to an encapsulated active halogen bleach and is characterized in that it comprises:
(I) 30 to 95 weight-56 active halogen bleach core;
(II) 2 to 40% by weight of a first coating material; and (III) 2 to 30% by weight of a second coating material having a melting point above that of the first coating material.
The invention further relates to a process for the manufacture of this product and of the kind mentioned in the introduction, and this process is characterized in that it comprises:
a) contacting the core particle with a sufficient amount of a first coating material to form a single coating for the core particle;
b) contacting the single-coated particle with a second coating material where it has a melting point above it to the first, thereby forming a coated particle having at least two coating layers;
c) heating the coated particle to a temperature above the melting point of the first coating but below the melting point of the second to form a liquid first coating layer; and
d) to solidify the liquid first coating.
Thus, it has been discovered that high-efficiency encapsulation of a number of core materials can be achieved by using a wide spectrum of coating materials by (i) surrounding the core material with a coating layer comprising at least two separate coatings with different melting temperatures, a first inner coating and a second or outer coating. , and (11) heating the coatings to a temperature and the melting temperature of the first or inner coating but below the melting temperature of the second or outer coating and the core material, for a sufficient duration to liquefy the first or inner coating.
Upon melting, the first coating (i) moistens the core and the second coating and (11) uniformly flows into the space formed between the core and the second coating. Upon cooling, the uniform, liquidized first coating will solidify to form a substantially continuous, smooth, non-porous and even coating on the core particle. The second or outer coating is used to hold the liquefied first coating in place and prevent agglomeration of the particles during the heat treatment process.
It has been found that this process works particularly well in a fluidized bed and is particularly useful for encapsulating bleach to be used in detergent compositions. Encapsulation of the bleaching agent allows it to be added to the detergent mixture without substantial loss of bleaching activity during preparation and storage of the detergent as the bleaching agent is isolated from incompatible or reactive detergent components. Therefore, the invention will be further described with reference to encapsulation of a halogen bleach component 1 a fluidized bed, but the invention is not intended to be unduly limited to this.
The number of mating coatings applied and heat treated according to the process is potentially infinite. For example, a core compound may be sequentially coated with coatings A, B, C and D where the melting point of the coatings is from, lowest to highest, A, C, B and D. After all four coatings are applied and solidified, the temperature of the quadruple coated capsule increased to above the melting points of the coatings A and C but below the melting points of the coatings B and D. The coatings A and B will become liquid and form substantially continuous, smooth, non-porous uniform coatings while coatings B and D will remain firm and retain liquid coatings A and C.
For purposes of the invention, fluidization temperature should be the temperature range within which a liquid coating sprayed onto fluidized particles adheres to and substantially surrounds the particles without the Fluidization temperature dependent upon significant agglomeration. among other factors of the core material being coated and used coating material.
Figure 1 is a schematic diagram of a fluidized bed apparatus used to encapsulate a core material according to the invention, and Figure 2 shows graphically the release rate of core material for various coated and treated encapsulated fabrics.
It has been found that very effectively encapsulated capsules, that is 90-99%, of a number of core materials by the use of a number of coating material can be easily and reasonably obtained. The capsule is formed by encapsulating the core particle with at least two coating layers which are then heat treated so that at least the inner coating is liquefied to form a substantially continuous, smooth, porous and uniform coating upon melting.
Then any substance or mixture of substances can be encapsulated as long as an individual particle of the substance can be maintained in discrete individual non-agglomerated state during the coating process. The fluidized bed, the preferred coating apparatus, is generally limited to solid core material. Therefore, the encapsulation process should be described with reference to a solid core material without wishing to be limited thereto. Of particular interest is the encapsulation of a solid halogen bleach, especially chlorine-releasing bleaching agent for use in detergent compositions.
Among the chlorine-releasing substances suitable as a core material are potassium dichloroisocyanurate, sodium dichloroisocyanurate, chlorinated trisodium phosphate, potassium hypochlorite, potassium hypochlorite, potassium hypochlorite, [(mono-trichloro) dimethylhydantoin, paratoluenesulfondichloramide, N-chloroammelin, N-chlorosuccinimide, Ν, Ν'-dichlorazodicarbonamide, chlorinated dicyandiamide, trichloro cyanuric acid, monotrichlorotetra (monocalcium dichloro-s-triazine trione), trichloro-s-triazinetrione. To achieve superior performance, the preferred chloroblock core material is sodium dichloroisocyanurate dihydrate, which is commercially available under the trademark CLEARON CDB-56.
For ease of processing and formulation, the particle size of the core material is preferably approx. 10-60 mesh US standard.
Virtually any substance which can be used as an inner coating as long as it is fixed at the usual storage temperature which is typically between -1 and + 38T and a melting point which is within the temperatures obtained in 1 coating apparatus, typically 40 to 94 ° C. The inner coating material is preferably inert with respect to the core material. If the inner coating material is potentially reactive with the core material, the core material may initially be coated with an inert material to prevent or delay any reaction between the core and the inner coating, the coating acting as a chemical barrier between the core and the other layers. This coating should have a melting temperature above the heat treatment temperature applied to the finished encapsulated product so that the coating does not become liquid and mix with the inner coating during the heat treatment. A useful precoating compound for a halogen bleach core to be used in a detergent composition will be a mixture of sodium sulfate and sodium tripolyphosphate having a melting point of approx. 590 to 870 ° C, at which temperature it tends to decompose. Sodium sulfate and sodium tripolyphosphate are relatively lean for halogen bleaches, have a very high melting point, and are components usually blended into detergent mixtures.
The inner coating material is preferably a substantially water-insoluble material for preventing passage of deactivating moisture to the bleach core and, if water-insoluble, preferably has a melting point below the bath temperature wherein the encapsulated material is used to support release of the core compound when it is released to the core compound. . A non-exhaustive list of substantially water-insoluble materials which can be used as inner coating material includes Ci<sub>2</sub>_<sub>2</sub>Qf<sup>e</sup>ttsyr<sup>e</sup>r such as sodium sulfate hydrate, stearic acid, palmitic acid and n-alkanoic acids; paraffin waxes; microcrystalline wax; C ^<sub>2</sub> ° £ higher primary and secondary solid alcohols; pluron surfactants with molecular weights between ca. 8000 and approx. 16500; primary and secondary alkyl sulfates; and alkali metal sulfonates. A useful inner coating material for a halogen bleach core material is a mixture of (i) C<sub>2</sub>o-fatty acids and (li) microcrystalline wax; the mixture having a melting point of approx. 43 to 60 ° C.
Virtually any substance can be used as an outer coating material as long as it is fixed at ordinary storage temperatures, typically between -1 and + 38 ° C. However, the melting point of the outer coating material must be greater than the melting point of the inner coating material below. Therefore, the choice of materials available for use as outer coating material depends on the inner coating material used. A non-exhaustive list of compounds useful as the second coat includes alkalies such as sodium carbonate, bicarbonate, -sequikarbonat and borate, phosphates dlammoniumfosfat, monocalcium phosphate, trikalslumfosfat, magnesium phosphate, calcium pyrophosphate, monokaliumortofosfat, ferric pyrophosphate, potassium pyrophosphate, dinatriumortofosfat, trlnatrlumortofosfat, tetrasodium pyrophosphate , sodium tripolyphosphate, sodium phosphate glass; neutral salts such as zeolites, sodium sulfate and chloride, and talc;
silicates and sillcate hydrates such as sodium luminescent leachate,
-secisilicate, dry sodium / potassium silicate water glass, sodium orthosilicate; organic sequestering agents such as copolymers of vinyl acetate and maleic anhydride, copolymers of acrylic acid and maleic anhydride, copolymers of maleic anhydride and ltaconic acid, polyacrylic acid; and N-alkylsulfonates; such as octyl sulfonate, sodium carboxymethyl cellulose, hydroxypropyl cellulose, hydroxyethyl ether of cellulose, hydroxypropyl methyl cellulose and known stable hydrates of these compounds. A useful outer coating material for a halogen bleach core when used throughout is a detergent composition, is a mixture of anhydrous sodium sulfate and sodium dipolyphosphate. 590 to approx. 870 ° C at which temperature the compound tends to decompose as sodium sulfonate and sodium tripolyphosphate fillers commonly used in detergent compositions.
In carrying out the method of the invention, the encapsulation is conveniently effected using the apparatus schematically shown in Fig. 1. Referring thereto, a coating chamber or a cylindrical or conical tower 10 is shown in which the coating or encapsulation of the core particles is carried out. At the bottom of the chamber 10 is a distributor plate 11. A supply of core particles 50 is placed in the chamber 10 carried by the distribution plate 11. A downwardly facing nozzle 12 constitutes a spray device which is adjustably arranged in the chamber 10, in a position 1 chamber so that liquid droplets of the coating material 15, discharged into a downwardly divergent three-dimensional spray pattern through the nozzle 12, precisely cover the upper surface area of an expanded web. the core particles 50. The nozzle 12 may also be positioned to spray upwardly on the vertebrate particles 50.
Coating solution 15 Is contained in a container 14 and fed to a nozzle 12 with a pump 16. Spraying the coating solution 15 through the nozzle 12 can be supported by compressed air via the nozzle 12 at the inlet 17.
A fluidizing gas stream obtained by a fan 19 (!) Passes through the duct 18 and (il) passes through perforations in the distribution plate 11. Before passing through the distribution plate 11, the gas is either cooled by the cooling system 20 or heated through the heat exchanger 21 to keeping the flue gas within the required fluidization temperature range. A persistent liquid coating material 15 contained in the container 14 is pumped by means of a pump 16 to the nozzle 12 where the coating 15 is sprayed onto the upper surface area 52 of the fluidized bed 51 until all particles 50 of the layer 51 are completely coated. Particles coated by the above procedure are encapsulated by a relatively continuous coating, substantially free-flowing and generally not agglomerated.
Subsequent coatings are applied in 1 sequence in the same manner, allowing sufficient time between the coatings to allow the previous coating to solidify and / or dry.
Multiple coatings can be applied in a single swirl layer 10 either by (i) applying a first coating, emptying the coating tank 14, filling the tank 14 with a second coating solution and applying the second coating; or (11) using separate solution tanks 14 and 14A for each coating solution 15 and 15A, each tank being in flow communication with the spray nozzle 12.
The multilayer coating may also be applied using separate fluidized layers for each coating.
In general, capsules having a core of active halogen bleaching agent, an inner and outer coating, will generally comprise ca. 30 to 95 weight- $ core, approx. 2 to 40 inner coatings and approx. 2 to 30% by weight of outer coatings, and for caps, for core, pre-coat, inner and outer coatings, the corresponding figures will be 3 to 95; 1 to 20; 2 to 40 and 2 to 30% by weight, respectively.
Example I
All percentages and ratios used in this example are by weight unless otherwise stated.
For the core material, approx. 11.7 kg commercial CLEATON CDB-56 granular dichloroisocyanurate dihydrate is a halogen bleach, with particle sizes of approx. 10 to 60 US mesh, arranged on a fluidized bed distribution plate substantially as in FIG. 1. The particles were fluidized by an upward flow of air which formed a fluidized bed having a height of ca. 15 to 30 cm. The temperature of the fluidized bed was maintained at ca. 43 tll approx. 54 ° C, i.e., the fluidization temperature of the first coating material to be applied.
In use, a known weight amount of a number of core particles 50 is applied to the distribution plate 11. Air is made to flow through the duct 18 and upwardly of the distribution plate 11 by the fan 19, to expand the fluidic layer of core particles, thereby keeping the particles 1 continuously moving 1 volume. 51 defined by the fluidized bed.
The precoat solution was prepared by dissolving part of a mixture of ca. $ 75 sodium sulfate and approx. $ 25 sodium trio polyphosphate 1 3 parts soft water. The pre-coating solution was sprayed onto the fluidized dichlorosocyananurate dihydrate particles until all particles were completely bleached. The ratio of core to pre-evaporation was approx. 3: 1.
The pre-coated capsules were heated to ca. 82 ° C and maintained in a fluidized state up to about $ 98 of the water in the pre-coating material was evaporated.
The inner coating material was prepared by melting a mixture of 85 $ stearic acid EMERSOL 153 and 15 $ ml microcrystalline wax WITCO Multivox 110-X. The mixture was melted by heating to ca. 64 to 93 ° C. The fluidized bed temperature was reduced to approx. 35 C and the inner coating material sprayed onto the pre-coated particles. The inner coating was sprayed onto the particles until all the particles were completely coated, after which the inner coating was allowed to solidify. The ratio between the core without the coating and the inner coating was approx. 3: 1.
The outer coating material was prepared by dissolving part of a mixture of ca. $ 75 sodium sulfate and approx. $ 25 sodium tripolyphosphate 1 approx. 3 parts of soft water. The outer coating was sprayed onto the capsules and dried in the same manner as described for the coating. During this step, however, the temperature of the fluidized bed was not allowed to exceed the melting point of the inner coating material of approx. 60 ° C, otherwise the inner coating would have become liquid and not encapsulated in the core particles. Therefore, the temperature of the fluidized bed was maintained at ca. 50 ° C while applying the outer coating. The ratio of core without front and bottom coatings to the outer coat before evaporation was approx. 2: 1.
After the addition and solidification of the outer coating, the vortex temperature was increased to approx. 60 to 65 ° C, above the melting point of the inner coating but below the melting point of the coating and outer coating. This made the inner coating material flow while allowing the core, the coating and the outer coating to remain firm. After liquefaction, the inner coating flowed freely around the core material, eliminating cracks, pores and other gaps in the coating and therefore increased the encapsulation efficiency. The liquid inner coating was held in place around the core particles at the solid outer core.
The finished encapsulated product was then cooled to below ca. 43C and removed from the fluldization chamber.
The finished dried encapsulated product had the following approximate composition based on the assumption that below <sup>14</sup> formulation of the product lost the core particles of sodium chlorochlorosocyanurate dihydrate a molecule of hydrated water.
Table I
Weight- $ based Sheet Material on finished product
<td>Core</td><td>Sodium dichlorosocyanurate (monohydrate)</td><td> 59,96</td>
<td>For-</td><td>sodium sulfate</td><td> 3,57</td>
<td>coating</td><td>Natrlumtripolyfosfat</td><td> 1,20</td>
<td></td><td>soft Water</td><td> 0,27</td>
<td>Inside-</td><td>Stearic acid (EMERSOL ”153)</td><td> 16,79</td>
<td>coating</td><td>Paraffin Wax (WITCO11OX)</td><td> 3,20</td>
<td>outer</td><td>sodium sulfate</td><td> 10,67</td>
<td>coating</td><td>Natrlumtripolyfosfat</td><td> 3,57</td>
<td></td><td>soft Water</td><td>Q., 77 100.00</td>
<td>Thus</td><td>Encapsulated bleach product can</td><td>released</td>
wash the water slowly by allowing the coatings to dissolve and / or the bleach to leak through the coatings, or faster melting or crushing of the coatings.
Example II
Five Single and Double Coat Samples Encapsulated tripolyphosphate (which is not a bleaching agent but used as a model core compound because phosphate analysis is light and accurate) particles, was generally prepared according to what is described in Example 1. core material to facilitate the measurement of the release of the core material. Coating materials, number of coatings, weight of coating and whether or not the capsule was heat treated 1 according to the invention is indicated in Table II.
it core- St inner coating- St outer coatingIdenti material in material 1 Inner coating material 1 Outer coating- Heat treatment fleering finished product finished product material finished product material (Yes / No)
<td>P</td><td>p</td><td>p</td>
<td>a</td><td>d</td><td>ten</td>
<td>TM</td><td>uh</td><td></td>
<td>rh</td><td>rh</td><td>rh</td>
<td> 3</td><td> 9</td><td></td>
<td>n</td><td>ω</td><td></td>
Β I • H * 4
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minutes 99.57 41.56 5.20 61.31 72.98 8.72 minutes 100.00 65.40 14.76 74.37 88.42 17.50 minutes 100.00 84.66 64.68 86, 48 98.32 78.86
The decay rates of the five samples and a sixth sample of Unencapsulated tripolyphosphate for reference were determined by placing part of the sample in a liter of water heated to 23.3 ° C and mixed with a leaf stirrer at a constant rate of 460 rpm. / mln. The size of the sample portion was chosen so that about 200 ppm phosphate from the core material would be present in the water when the core was completely dissolved. The timing began when the sample was added to the water. A MODEL 254-PLASMA 100 spectrometer was used to monitor the release of phosphate to the solution. This sample preparation was extracted continuously in 1 ml of water per ml. my. and tested the concentration of tripolyphosphate 1 this. The results are tabulated in Table III and graphically shown in FIG. 2.
As can be readily seen from Fig. 2, the encapsulation process of the invention reduced by samples 3 and 6 quite significantly the decay rate of the core material as compared to encapsulation without the use of the heat treatment step, indicating an increase in coating efficiency.
The foregoing should not limit the invention because many variations and embodiments are conceivable without departing from the spirit and scope of the invention.
Contents3
9 sheets
Sheet 1 Sheet 2 Sheet 3 Sheet 4 Sheet 5 Sheet 6 Sheet 7 Sheet 8 Sheet 9
22 members in 10 offices
Priority claims4
| Document | Office | Kind | Date |
|---|---|---|---|
| 83827686 | United States of America | A | |
| 83827686 | United States of America | A | |
| 838276 | – | – | – |
| US19860838276 | – | – | – |
Members22
| Document | Office | Kind | |
|---|---|---|---|
| NO863665D0 | Norway | D0 | |
| FI865349A0 | Finland | A0 | |
| US4657784A | United States of America | A | |
| FI865349A | Finland | A | |
| FI865349A7 | Finland | A7 | |
| FI865349L | Finland | L | |
| NO863665L | Norway | L | |
| AU6163086A | Australia | A | |
| JPS62227440A | Japan | A | |
| EP0244550A2 | European Patent Office (EPO) | A2 | |
| US4731195A | United States of America | A | |
| EP0244550A3 | European Patent Office (EPO) | A3 | |
| NZ217225A | New Zealand | A | |
| AU582265B2 | Australia | B2 | |
| NO166290BThis record | Norway | B | |
| NO166290C | Norway | C | |
| EP0244550B1 | European Patent Office (EPO) | B1 | |
| AT72522T | Austria | T | |
| ATE72522T1 | Austria | T1 | |
| DE3683905D1 | Germany | D1 | |
| ES2038126T3 | Spain | T3 | |
| JP2625113B2 | Japan | B2 |
Numbers
- Publication, DOCDB
- 166290
- Publication, EPODOC
- NO166290B
- Application
- 863665
- Application, DOCDB
- 863665
- Application, EPODOC
- NO19860003665
Titles2
- English
- WRAPPED, ACTIVE HALOGEN Bleach, AND MANUFACTURING THEREOF.
- Norwegian
- INNKAPSLET, AKTIVT HALOGENBLEKEMIDDEL SAMT FREMSTILLING DERAV.
Classification
- CPC, 5
- B01J2/006
- C11D3/395
- C11D17/0039
- Y10T428/2991
- Y10T428/2998
- IPC, 8
- B05D1 22
- B01J2 00
- B01J13 02
- B01J13 04
- C01B11 06
- C11D3 395
- C11D17 00
- C11D17 08
