Aqueous polychloroprene composition containing zinc oxide nanoparticles is useful for coating, impregnating, laminating, sealing or especially bonding e.g. wood, paper, plastics, textile, leather, rubber or inorganic material or as insulant

The Invention relates to water-containing compositions, especially aqueous Polymer dispersions based on polychloroprene, a process for their preparation and their use, in particular for preparing of coatings in particular for the production of adhesive coatings and a method of bonding substrates using of the compositions.

Contact adhesives based on polychloroprene (CR) are predominantly solvent-containing Adhesives dried applied to be joined substrates and will. subsequent Include the Substrates obtained under pressure you immediately set up a connection with high initial strength after the joining operation. The subsequent leading networking definitively Curing.

For ecological establish is a growing need for suitable aqueous CR adhesive dispersions, the to corresponding aqueous CR adhesive formulations be processed. These are used for example in the "spray mix" process, wherein the aqueous Adhesive formulation and a coagulant separately in a spray gun promoted and finally in spray are mixed, and then the CR-adhesive coagulated on the substrate. An overview to this method, for example in "Handbook of Adhesives", Irving Skeist, Chapman, Hall, New York, 3rd Ed. 1990 Part 15, page 301, R. Musch et al, Adhesives Age, January 2001, page 17, "Spray Mixing adhesives basic Dispercoll®^®C for the foam-bonding ", Technical Information Bayer AG, no. KA-KR-0001d / 01 / 05.96 given.

It However, it is often necessary, the aqueous dispersions or CR Formulations with additives such as stabilizers to enable to make this a need-based storage stability and safety of use are having or the adhesive layers from aging or discoloration protected.

To the latter purpose are aqueous Formulations advantageously mixed with zinc oxide, since this case Formulations based on polychloroprene dispersions a quick Aging of the adhesive seam and discolouration the bonded substrates by elimination of HCl from the CR-polymers counteracts.

The However, previously known zinc oxide types are susceptible to sedimentation or known zinc oxide dispersions in a phase separation (So-called. Phasing). This sedimentation or phase separation is particularly when use of such adhesive formulations in "spray mix" process not acceptable since it leads to clogging of the nozzle. The cleaning of the nozzle is time- and cost-intensive and economically unsatisfactory.

Around To resolve the problem of sedimentation of zinc oxide, are different The method has been described to form stable, non-sedimenting Zinc oxide dispersions produce.

DE-A 19703582 describes the production of a zinc oxide paste by a commercial Zinc oxide processed with a wetting agent to an aqueous zinc oxide paste becomes. This paste has for the application in aqueous Adhesive dispersions a number of disadvantages. Firstly, the paste is highly viscous and thixotropic, indicating poor processability entails. It should also after incorporation in the aqueous Adhesive dispersion restricted sedimentation, because the zinc oxide particles in commercial Zinc oxides present highly agglomerated and described by the Process, the agglomerates are not completely dispersed. Additional property amenities by agglomeration the reactive surface is only partially available, that relatively high amounts of zinc oxide must be used to the desired Effect of HCl-absorption to reach.

WO95 / 24359 describes a colloidal zinc oxide as well as a process for preparing colloidal solutions conventionally by milling, strongly agglomerated zinc oxides in the presence of polyacrylic acid, wherein the colloidal solution Agglomerates of <100 contains nm. This method has the disadvantage that to overcome the strong interaction the agglomerated particles a very intense grinding process required is to obtain stable dispersions having agglomerate sizes of <100 nm. The process requires Thus a very high technical effort, is very energy-intensive, Allowed only small throughputs and is therefore an economic Production of technical product quantities unsuitable. Additional property amenities also due to agglomeration the reactive surface only partially available, are used so that relatively high amounts of zinc oxide have to, to provide the desired to achieve effect of the HCl absorption.

Out the prior art is the use of nano-zinc oxide dispersions for different known applications. By the term "nanoparticles" or "nanoparticles" refers generally Particles having a diameter of less than about 100 nm.

On Due to the large reactive particle surface suitable nanoparticulate located Zinc oxide as a catalyst. Specifically, meaning it as an activator for the Crosslinking of polymers, especially rubbers, such as in WO02 / 083797 describes. In comparison with conventional zinc oxides with a smaller active surface will have lower amounts of nanoparticulate zinc oxide a comparable reached polymer crosslinking.

Zinc oxide nanoparticles with particle sizes below about 30 nm are about addition, for use as UV absorbers in transparent organic-inorganic Hybrid materials, plastics, coatings and non-stick coatings suitable. In addition, is also a use for protecting UV-sensitive organic dyes and pigments possible.

particle or agglomerates greater than about 30 nm, lead to scattered light effects and thus to an undesirable decrease in transparency in the range of visible light.

The Object of the present invention was to provide an aqueous phasingstabilen adhesive composition after application on the substrates to be bonded and joining a high resistance having to elimination of HCl from the polymer and the Application in spray, as the "spray mix" suitable procedure is, without leading to clogging of the nozzles.

It it was found that by a combination of polychloroprene dispersions and certain aqueous Nano-ZnO dispersions adhesive formulations are produced can, which no settling show and from the processing itself in very thin Films show no specks. They have good resistance opposite to HCl elimination.

object of the present invention is a composition comprising: <ul><li>a) polychloroprene particles,</li><li>b) zinc oxide particles whose average particle size less than 150 nm, and</li><li>c) water.</li></ul>

The The composition is in particular in form of an aqueous Dispersion.

Polychloroprene particles in the sense of the invention means particles of polychloroprene (poly (2-chloro-1,3-butadiene)) and of chloroprene-containing copolymers.

The Polychloroprene (poly (2-chloro-1,3-butadiene)) - the particles are composition of the invention useful in the form of aqueous Dispersions supplied. The preparation of such polychloroprene dispersions is in itself known, and they are, for example, by emulsion polymerization of chloroprene and, optionally, a monomer copolymerizable with chloroprene ethylenically unsaturated Monomers prepared in an alkaline medium, such as in WO02 / 24825 (Page 3, lines 26- page 7, line 4), DE-A 3,002,734 (p.8, Z. 23- 12 S., Z. 9) or US Patent 5,773,544 (col. 2, line 9 to col. 4, line 45) described. Particularly preferred are polychloroprene dispersions, the continuous by Polymerization are prepared as described for example in WO02 / 24825, Example 2 and DE-A 3002734 Example 6, wherein the regulator content can be varied between 0.01 and 0.3 wt .-% .-%.

In a preferred embodiment, the invention, the polychloroprene particles have an average primary particle diameter of less than 220 nm.

Of the Term "primary particles or primary particles "refers to analog to DIN 53206; 1992-08 by appropriate physical processes as Individuals recognizable particles. One can in conjunction with the speak Polychloroprenpartikeln of "diameters", since the particles approximately spherical are.

Of the average primary particle diameter the polychloroprene particles according to the invention preferably by ultracentrifugation determined, cf .: HG Müller, Progr. Colloid Polym. Sci. 107, 180-188 (1997). It is the&lt;?page 4?&gt;center of mass indicated.

On average primary particle diameter of more than 220 nm is disadvantageous because it is of the in removing residual monomers of 2-chloro-1,3-butadiene from the polychloroprene unwanted dispersion by steam distillation Precipitations comes.

In a further preferred embodiment the invention, the polychloroprene particles have a mean Primary particle diameter of more than 60 nm.

On average primary particle diameter of less than 60 nm is disadvantageous because the polymer dispersion very difficult to have a solids content of&gt; 55 wt% concentrate. leaves.

Prefers , the polychloroprene particles have an average primary particle diameter from about 60 to about 220 nm, more preferably about 70 to about 160 nm on.

The said average primary particle diameter the polychloroprene particles are present both in the preparation for the compositions of the invention aqueous used Dispersions and also in the resulting compositions according to the invention in front.

The compositions of the invention further contain zinc oxide particles whose average particle size less than 150 nm, preferably less than 100 nm more preferably less is 50 nm. There the zinc oxide particles are not spherical, is called the average particle size in difference the average particle diameter.

The Zinc oxide can in the compositions of the invention both as a so-called primary particles as present in the form of agglomerates. The term "average Particle size of the ZnO particles "is intended to mean the means Ultracentrifugation certain average particle size and includes the size of primary particles and optionally present agglomerates thereof (cf. .: HG Müller, Progr. Colloid Polym. Sci. 107, 180-188 (1997)). It is the center of mass indicated).

The measured by ultracentrifugation, weight average mean Particle size is a maximum of 150 nm, preferably max. 100 nm and more preferably max 50 nm, wherein preferably at least 90 wt% of all particles smaller than 200 nm, preferably less than 150 nm and particularly preferably less than 100 nm.

A average particle size of more than 150 nm is disadvantageous because the risk of sedimentation is and the product is less reactive.

by means of TEM photographs (transmission electron micrographs) let yourself by counting and statistical analysis analogous to WO 00/50503, the number average Particle size of the ZnO primary particles determine. As already mentioned above, the term "primary particle or primary "analogous to DIN 53206; 1992-08 recognizable by appropriate physical processes as individuals particles.

The average particle size of the primary particles is maximum 100 nm, preferably at most 50 nm, preferably a maximum of 30 nm, more preferably at most 15 nm.

The compositions of the invention the zinc oxide particles are suitably in the form of aqueous ZnO dispersions supplied with a mean particle size of &lt;150 nm. This aqueous dispersions can additionally organic solvents and / or surface modifying Compounds. The ZnO particles can either from non-agglomerated ZnO primary particles or ZnO agglomerates or mixtures of the dispersed primary particles and ZnO ZnO agglomerates consist whose dimensions can be as described above.

In a further preferred embodiment the invention, in the aqueous dispersion to a ZnO- Zinc oxide sol having an average primary particle size of less than 30 nm, preferably less contains than 15 nm. The sol Water optionally mixed with high-boiling solvents, such as Triethanolamine or ethylene glycol. The particle sizes of the aqueous employed agree ZnO dispersions with particle sizes in the inventive compositions agree ie they change their Particle surface Incorporation into the compositions of the invention not substantially.

In a preferred embodiment, the invention includes compositions of the invention further Additives, such as in particular silica particles. The silica particles to lead in combination with zinc oxide in an increase in the viscosity of the adhesive dispersion.

Prefers , the average silica particle size or the average diameter the silica particles (the particles are approximately spherical) determined, by ultracentrifugation (as indicated above), in the range of 1 to 400 nm, more preferably in the range of 5 to 100 nm, particularly preferably in the range of 8 to 50 nm. The average silica particle diameter closes the particle diameter of the primary particles and optionally present agglomerates. The compositions of the invention are the silica particles preferably in the form of aqueous Silica dispersions having an average particle diameter the SiO₂Particles of 1 to 400 nm, preferably 5 to 100 nm, particularly preferably 8 to 50 nm, respectively.

Especially said aqueous are preferred Silica dispersions in the form of water-containing silica sols the compositions of the invention supplied. The particle sizes of the Silica sols used are when incorporated into the compositions of the invention substantially no change.

In a further preferred embodiment the invention includes compositions of the invention at least an antioxidant agent, that different from the above-described ZnO-particles is. Preference is given to anti-aging agent to the Based on oligofunctional secondary aromatic amines and / or oligo-substituted phenols.

The in the present invention preferably for the preparation of the compositions according to the invention aqueous used Dispersions of zinc oxide with an average particle size &lt;150 nm can on different ways to be prepared. Particularly suitable However, such methods in which the zinc oxide particles by precipitation from a zinc salt solution be prepared with an alkali and further processed at closing to a dispersion will. Examples are:<ul><li>I) A Zinc oxide sol such as described in WO 00/50503, produced by Redispersing zinc oxide gels having an average primary particle size of ≤ 15 nm. solvent are water or water-ethylene glycol mixtures in question, where appropriate additional surface modifying Compounds. or</li><li>II) Zinc oxide sols, such as described in WO02 / 083797 having average Primary particle size of &lt;30 nm and average Agglomerate size of &lt;100 nm, for example, prepared by the process described in WO02 / 083797 process.</li></ul>

As well suitable for preparing the compositions of the invention are ZnO dispersions with surface-modified Zinc oxides as described for example in DE-A 10163256, for example, be prepared by any of the methods described there.

Aqueous dispersions of silica used to prepare compositions of the invention may be used have long been known. Depending on the manufacturing process, they are in different structure before.

Suitable according to invention Silica dispersions can on the basis of silica, silica gel, pyrogenic silicas or Precipitated silicas or Mixtures of the above, obtained and are in <patcit><text>DE 10224898.2</text></patcit> been described.

Will for the preparation of the compositions according to the invention as isolated Solids present SiO₂Raw materials with as For example, fumed or precipitated silica used, they will be in an aqueous SiO₂Dispersion transferred by dispersing.

to Preparation of silicon dioxide dispersions dispersants of the prior art used, preferably those used to generate high shear rates are suitable, such as Ultratorrax or dissolver discs.

Prefers are those aqueous Silica dispersions used, the SiO₂particles a mean particle diameter of 1 to 400 nm, preferably from 5 to 100 nm and particularly preferably 8 to 50 nm. In the case, that precipitated silicas are used, this order will Teilchenver&lt;?page 6?&gt;kleinerung ground.

Preferred inventive polymer dispersions are those in which the SiO₂Particles of silica dispersion d1) are present as discrete non-crosslinked primary particles.

It is also preferred that the SiO₂Particles with hydroxyl feature on the particle surface.

Especially preferably as an aqueous Silica dispersions aqueous silica sols used.

at the anti-aging agents d2) does not constitute the zinc oxide particles b) but preferably those based on oligofunctional secondary aromatic amines or oligofunctional substituted phenols as products of type 6 PPD, DTPD, DDA, BPH, BHT etc. such as described in manual the rubber industry, 1992 edition, Bayer AG, Leverkusen chapter. 4 Vulkanox.RTM^®. 423. It is particularly effective Vulkanox.RTM^® DDA a diphenylamine derivative.

to Preparation of the compositions according to the invention mixing appropriate aqueous dispersions of components a), b) and d1) in proportions of: <tables><table><tgroup cols="2"><colspec colname="1" colwidth="1*" /><tbody><row><entry colname="1">Polychloroprene dispersion (A)</entry><entry colname="2">from From 50 to 99.99 wt .-%,</entry></row><row><entry colname="1">Zinc oxide dispersion (B)</entry><entry colname="2">from 0.01 to 10 wt .-%,</entry></row><row><entry colname="1">Silica dispersion (D1)</entry><entry colname="2">from 0 to 40 wt .-%.</entry></row></tbody></tgroup></table></tables>wherein the weight .-% - details in each case on the solids content the composition relate, which adds up to 100% (The following weight data relate to the solids content is indicated unless otherwise.). The solids content or Solids content referred to here is the weight of the non volatile components, such as in particular the polychloroprene, the ZnOS and the SiO₂, Volatile shares include especially the high-boiling solvent, which at up to 250 ° / 15 torr can distill. The solids content is added to 100 wt .-% on. additionally , the anti-aging agent (d2) in amounts of preferably 0 to 10 wt .-%, preferably 0 to 3 wt .-% based on the solids content the composition may be added.

For the production phasingstabiler mixtures containing polymer dispersions of the invention preferred an amount of 90 wt .-% to 99.9 wt .-% of a polychloroprene dispersion (A) and a share of 10 percent .-% to 0.1 wt .-% of a zinc oxide dispersion (B), said percentages being based on the solids content of the composition relate.

For the production adhesives with an excellent resistance to the elimination of HCl can still preferred 0.1 to 10 Wt .-%, more preferably from 0.2 to 3 Wt .-% of another anti-aging agent (d2) preferably on based on oligofunctional secondary aromatic amines or oligo-substituted phenols (d2) alone or in combination are added with 2 wt .-% to 30 wt .-% of a silica sol dispersion (d1).

furthermore The inventive composition may 0 to 79.99 wt .-% further customary for adhesives and admixtures contained.

among them mean, for example, other polymers, such as polyacrylates, Polyvinylidene chloride, polybutadiene, polyvinyl acetate and / or styrene-butadiene rubbers, the preferred aqueous form Dispersions in an amount of up to 30 wt .-%, based on the may be added to solid content of the composition. Such polymers can are used to the property profile of the adhesive compositions to modify.

More Examples of the adhesive auxiliaries and additives are for example fillers, such as quartz powder, quartz sand, barite, calcium carbonate, chalk, dolomite or talcum, optionally together with wetting agents, for example, Polyphosphates such as sodium hexametaphosphate, naphthalenesulfonic acid, ammonium or Sodium polyacrylic acid salts are added, the fillers in amounts of preferably up to 75 wt .-%, more preferably 10 to 60 Wt .-%, more preferably from 20 to 50 wt .-%, and the wetting agent in amounts of 0.2 to 0.6 wt .-%, all statements relate to the amounts of solids of the composition are added.

The Amount of the fillers added depends, among alia, on whether the compositions of the invention as an adhesive or used as a sealant. When used as adhesive are maximum levels of fillers Wt .-% preferably from about 30 to 40, based on the solids content of the composition. It is a content of polychloroprene particles preferably of more than 40 wt .-%.

at the application as a sealant are maximum levels of fillers Wt .-% preferably from about 60 to 75, based on the solids content of the composition. It is a content of polychloroprene particles preferably less than 40 wt .-%.

More suitable auxiliaries are, for example, in amounts of about 0.01 to 1 wt .-%, based on the solids content, to be used organic Thickeners such as cellulose derivatives, alginates, starch, starch derivatives, Polyurethane thickeners or polyacrylic acid, or in quantities of 0.05 to 5 wt .-%, based on the solids content, to be used inorganic thickeners, such as Bentonite.

to preservative can the adhesive composition of the invention also fungicides are added. These are, for example Amounts of 0.02 to 1 wt .-%, based on nonvolatile fractions, for use. Suitable fungicides are, for example, phenol and Cresol or organotin compounds.

Possibly can tackifying resins such as unmodified or modified Natural resins such as rosin esters, hydrocarbon resins or synthetic Resins such as phthalate polymer dispersion of the invention in dispersed Form may be added (see example in "adhesive resins" R. Jordan, R. Hinterwaldner, pp 75-115, Hinterwaldner Verlag München 1994). Preferably Alkylphenolharz- and terpene phenol resin dispersions with softening points above 70 ° C, particularly preferably greater than 110 ° C.

furthermore can Plasticizers, such as those based on adipate, phthalate or phosphate, for example, in amounts of from 0.5 to 10 wt .-%, based on the solids content be added.

Of the Solids content of the composition according to the invention is based on the total weight of the composition preferably at least about 50 wt .-%, more preferably at least about 60 wt .-%, more preferably more than 70 wt .-%, corresponding to a proportion of the volatile Components of the inventive composition of preferably less than about 50 wt .-%, more preferably less than about 40 wt .-%, more preferably less than about 30 wt .-%.

Of the Water content relative to the total weight of the volatile Components of the composition according to the invention is preferably to 50 to 100 wt .-%.

Organic Solvent, such as toluene, xylene, butyl acetate, methyl ethyl ketone, Ethyl acetate, dioxane, triethanolamine, ethylene glycol or mixtures thereof can According to the invention in the Composition may be contained. The organic solvent can the water-containing compositions of the invention in small quantities of a maximum of about 50 wt .-%, based on the total amount the volatile Ingredients are added. They serve, for example, the to improve adhesion to difficult to bond substrates.

On Another object of the invention is a process for preparing the compositions of the invention, characterized in that an aqueous polychloroprene dispersion (A) with an aqueous zinc oxide dispersion (b) and optionally with a Silica dispersion (d2) and / or an aging agent (c1) and optionally adding the usual For adhesives and additives are added.

On preferred method for preparing the compositions according to the invention is characterized in that first an aqueous polychloroprene dispersion (a) with an aqueous zinc oxide dispersion (b) and the anti-aging agent d1) and mixed with the adhesive auxiliaries and additives and agents the silica sols (d2) while or be added after mixing.

Of the Application of the adhesive formulation may in known ways, for example, by brushing, pouring, Knife coating, spraying, rolling or dipping performed. The drying of the Adhesive film can be carried out at room temperature or elevated temperature up to 220 ° C.

Prefers done the job by spraying such. B described in <patcit><text>EP 624 634 B1 0</text></patcit>,

The compositions of the invention can are used as adhesives or as sealants. Prefers is the application as an adhesive.

On Adhesive is according to DIN 16920, a non-metallic material, the joining members by surface adhesion (Adhesion) and internal strength (cohesion) can connect.

The adhesives of the invention used for example for bonding any desired substrates of the same or various kinds, such as wood, paper, plastics, textiles, Leather, rubber or inorganic materials such as ceramics, stoneware, Glass fibers or cement, but also for impregnations, coatings and lamination of fabric and paper, as binders for fibers or to enhance of toecaps and as insulation material.

A. Substances Used

table 1: polychloroprene <img img-content="tb" img-format="tif" he="30" wi="140" file="00160001.tif" />

Of the average particle diameter of Polychloroprenpartikel was 95 nm. Table 2: silica dispersion <img img-content="tb" img-format="tif" he="38" wi="142" file="00160002.tif" /> table 3: used in the invention ZnO dispersion <img img-content="tb" img-format="tif" he="38" wi="143" file="00170001.tif" />&lt;?page 9?&gt; table 4: Additives, Auxiliary <img img-content="tb" img-format="tif" he="106" wi="144" file="00170002.tif" />Bayoxide^®Z VP 9802 aqueous zinc oxide dispersion with a particle size of 50 000-150 000 nm.

Manufacture of inventively used Nano zinc oxide - dispersion A

The Production of nano-zinc oxide dispersion A is granted according to WO00 / 50503 Described Example 1 (Preparation of Zinkoxidgels in methanol of zinc acetate dihydrate). The preparation of the zinc oxide sol comprising the zinc oxide gel success similar to Example 7 in this document, which the zinc oxide gel is mixed with water and triethanolamine and the proportion of methanol is stripped off in vacuum, so that a nano zinc oxide dispersion in triethanol / water is formed. The average primary particle size is 10.5 nm (number average) the zinc oxide at 20%.

C. measuring methods

C1 Determination of spray behavior

inserted Device: Spray-Mix unit from. Krautzberger GmbH, 65333 Eltville. 2 pressure vessel a volume of: <ul><li>1. 1,85 liter TUEB No .: 22 A0 012 967;</li><li>2. 10 liters TUEB No .: 22 A0 012 968</li></ul>and a spray gun and a vent system. Of the 1.85 liter pressure vessel is to operate at a maximum pressure of 2.5 bar, the 10 liter Pressure vessel with a maximum pressure of 6 bar. The spray mix gun has three Leads to dispense the adhesive formulation of the coagulant and the atomizing air.

implementation of Measurement: In the larger container the dispersion in the smaller container is filled, the coagulating solution. spray jet and adhesive application is by the amount of atomizing air regulated.

at the experiments is used as the coagulant a 2.5% aqueous calcium chloride solution. During spray application is the volume-ratio between adhesive formulation and Koagulationsmit&lt;?page 10?&gt;tel 10: 1.

C2 determine the sedimentation

manufacturing an adhesive based on polychloroprene dispersion invention

For the production of the formulation is the polychloroprene dispersion in a beaker presented. With stirring are the stabilizer, the anti-aging agent, the resin and to stain the dispersion Levanyl^® blue added. Thereby can make deposits of zinc more visible.

evaluation

Of the Adhesive approach is daily examined for phase separation and judged according to the following legend:

<dl><dt>0</dt><dd>= No change</dd><dt>1</dt><dd>= Slight sediment formation on the ground</dd><dt>2</dt><dd>= Strong sedimentation on the ground</dd><dt>3</dt><dd>= Solid precipitation on the ground</dd></dl>

C3. Determination of the Thermal Stability (HCl stability)

The exam the dried adhesive samples is carried out in conformity with DIN 53381, method B

Performing the measurement:

<ul><li>meter: 763 PVC - Thermomat Metrohm, CH-9101 Herisau, Switzerland</li></ul>

The Samples (thickness 0.1-1 mm) are cut to an edge length of about 2-3 mm, weighed 0.2 g in a test tube and the measurement at 180 ° C and air as carrier gas performed. is measured the electrical resistance of water, in which the formed HCl gas dissolves again. As the HCl stability shall indicate the date at which the electrical resistance the value of 50 ĩS / cm has reached. The higher the Value is, the more stable the measured sample to HCl elimination.

D results:

D1: Determination of spray behavior

table 5: preparation of the formulation of the comparative studies (data in parts by weight dispersion) <img img-content="tb" img-format="tif" he="67" wi="127" file="00200001.tif" />

&lt;?page 11?&gt;

spray behavior <img img-content="tb" img-format="tif" he="97" wi="145" file="00210001.tif" />

As the experiment 1 shows, continues during the standstill phase Zinc oxide in the vessel and in the Hose, giving easy start on day 2 and 3 not longer possible is. When used according to the invention of Nano-zinc oxide is a perfect spraying of the dispersion after a longer Life in the apparatus possible.

D2: Determination of sedimentation

table 6 Preparation of the formulation for comparative studies (data in parts by weight dispersion) <img img-content="tb" img-format="tif" he="82" wi="127" file="00220001.tif" />

&lt;?page 12?&gt;

sedimentation of the final formulation <img img-content="tb" img-format="tif" he="74" wi="102" file="00220002.tif" />

During the inventive use of nano-zinc oxide (approach 4) phase separation does not occur is done, in the standard formulation 3 after one day precipitation of zinc oxide, which after a few days to a solid deposit compacted.

D3: Determination of thermal stability

D3.1 thermostability a polychloroprene formulation in the presence of nano-silica <img img-content="tb" img-format="tif" he="122" wi="150" file="00230001.tif" />

&lt;?page 13?&gt;

<img img-content="tb" img-format="tif" he="198" wi="136" file="00240001.tif" /> Fig. 1 Stability polychloroprene against HCl elimination

As the graphics can be seen, leads the Nano invention Zinc oxide dispersion (attempt 5-14) to a significantly better resistance polychloroprene over Elimination of HCl as a standard for conformity with ZnO dispersion.

&lt;?page 14?&gt;

D3.1: thermostability a polychloroprene formulation without nano silica dispersion information in parts by weight Dispersion (in grams) <img img-content="tb" img-format="tif" he="90" wi="145" file="00250001.tif" />

The Table shows that the ZnO-free formulation No. 20, only a small resistance has against HCl elimination, a market ZnO dispersion (no. 21, 22) the resistance opposite to improved HCl elimination, equal amounts of zinc oxide according to the invention (Nos. 23, 24), the resistance but significantly increase.

As A comparison of runs 6, 7 and 25 show, the addition nano silica at low zinc oxide dispersion, an additional Stabilization against HCl elimination.