DE102007018661A1 - Use of nano-urea particle as stabilizers and additives for aqueous polychloroprene-dispersions, -coating and -adhesives - Google Patents

Abstract

The The invention relates to the use of nanoureas for stabilization of polychloroprene dispersions.

Description

The The invention relates to the use of nanoureas as additives to increase the stability of polychloroprene dispersions, Coatings and adhesive compounds.

Contact adhesives based on polychloroprene (CR) are predominantly solvent-based Adhesives applied to substrates to be bonded and dried become. By subsequent joining of the substrates Under pressure you get a connection with high Initial strength immediately after the joining process. The subsequent crystallization leads to the final Curing.

For ecological reasons, there is an increasing demand for suitable aqueous CR adhesive dispersions which can be processed to corresponding aqueous CR adhesive formulations. These are used, for example, in the "spray-mix" process, in which the aqueous adhesive formulation and a coagulant are conveyed separately in a spray gun and finally mixed in a spray jet, whereupon the CR adhesive coagulates on the substrate eg 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 Based on Dispercoll® C for Foam Bonding" . Technical Information of Bayer AG, No. KA-KR-0001d / 01 / 05.96 given.

It however, the aqueous CR dispersions are often required or formulations with additives such as stabilizers to give them a needs-based storage stability and safety of use or even the adhesive layers and adjacent components from aging or discoloration are protected.

To the latter purpose, aqueous formulations are advantageous added with zinc oxide, since this in formulations based on Polychloroprene dispersions of a rapid aging of the bond line and discoloration of the bonded substrates by cleavage of hydrogen chloride (HCl) from the CR polymer counteracts.

The However, previously known zinc oxide types tend to sedimentation or the known zinc oxide dispersions for a phase separation (so-called phasing). This sedimentation or phase separation is particular when using such adhesive formulations in the "spray-mix" Procedure unacceptable as it causes blockage of the nozzle leads. The cleaning of the nozzle is time consuming and costly and unsatisfactory from an economic point of view.

WO2004 / 106422 describes the use of nano-scale (<100 nm) zinc oxide particles which, due to their small particle size, are not prone to sedimentation. However, the preparation of the zinc oxide particles is associated with a complicated synthesis procedure. In addition, in their use, which is preferably carried out in combination with silica particles or aqueous silica sols to increase the initial strength, it is disadvantageous that, when larger amounts of silicon dioxide particles are metered in, a very strong viscosity build-up occurs up to a pasty viscosity. This prevents the use of such formulations in applications in which a low viscosity is absolutely necessary, for example in applications in which the adhesive is sprayed.

Generally disadvantageous is the use of zinc oxide in adhesive formulations, because in the course of processing the adhesives or cleaning the tools used during processing impure contamination of the product Sewage can not be excluded. This should be avoided because zinc oxide is very toxic to aquatic organisms and this a handling according to the hazardous substance labeling N = "Dangerous for the environment" necessary.

Of the Use of nanoscale urea particles in polychloroprene dispersions is known per se, the previous investigations in terms have gone on an adhesive reinforcement. In how far down by Nanoharnstoff particles further properties of polychloroprene dispersions can be influenced favorably, has not been studied or described.

It it has now been found that nano-urea particles are beneficial in polychloroprene dispersions for stabilization against phase separation as well as for better protection against aging of the adhesive seam and discoloration of the bonded substrates by HCl action can be inserted.

The present invention is therefore the use of nanourea particles as Stabilizers for aqueous polychloroprene dispersions.

Prefers The nanourea particles provide improved stability against phase separation of the dispersions and better protection against aging phenomena produced from these dispersions Adhesive seams and discoloration of the bonded substrates by HCl action.

The Nanourea particles can be discrete next to the polychloroprene particles or else by interactions and agglomeration completely or partially associated with the polychloroprene particles in the Be contained dispersion.

Such dispersions of the invention are by mixing of aqueous polychloroprene dispersions with nanourea particles available, wherein the nanourea particles preferably also be introduced as an aqueous dispersion.

The preparation of the underlying polychloroprene dispersions is known per se. They are prepared for example by emulsion polymerization of chloroprene and optionally a copolymerizable with chloroprene ethylenically unsaturated monomers in an alkaline medium, such as. In WO02 / 24825 3, Z. 26-S.7, Z.4), DE-A 3 002 734 8, Z. 23-S.12, Z. 9) or US Pat. No. 5,773,544 (Sp. 2, No. 9 to Sp. 4, No. 45).

Next The polychloroprene particles can be further polymer particles such as polyacrylate, styrene-butadiene, acrylonitrile-butadiene, polyurethane and / or polyvinyl acetate particles.

The Nanourea dispersions preferably used according to the invention contain intramolecular organic crosslinked by urea groups Particles, typically one size from 5 to 800 nm, preferably 20 to 500 nm, particularly preferably 50 up to 150 nm, determined by means of laser correlation spectroscopy (LKS) measurements (Measurement of a 1: 100 sample diluted with water at 23 ° C) exhibit.

Such Nanourea dispersions are available by hydrophilized Polyisocyanates are introduced into water and then the present free isocyanate groups by an isocyanate-water reaction degraded to primary or secondary amine. These Amino groups then form by reaction with further isocyanate groups Urea groups and thereby crosslinked to nanourea particles, in the form of aqueous dispersions. In principle, it is possible that NCO groups of the hydrophilicized polyisocyanates before or during the reaction with water with other isocyanate-reactive compounds such as primary or secondary amines and / or alcohols be implemented.

When Hydrophilized polyisocyanates can all themselves be known to those skilled in the art known NCO-containing compounds are used, the nonionic or potentially ionic hydrophilic. Become Mixtures of different polyisocyanates of the above Art used, it is preferred that at least one polyisocyanate having a nonionic hydrophilic moiety. Especially Preference is given exclusively to polyisocyanates with nonionic used hydrophilicizing groups.

By ionic or potentially ionic hydrophilizing compounds are meant all compounds containing at least one isocyanate-reactive group and at least one functionality, such as. B. -COOY, -SO ₃ Y, -PO (OY) ₂ (Y, for example = H, NH ₄ ⁺ , metal cation), -NR ₂ , -NR ₃ ⁺ (R = H, alkyl, aryl), having when interacting with aqueous media enters a pH-dependent dissociation equilibrium and can be charged in this way negative, positive or neutral. Preferred isocyanate-reactive groups are hydroxyl or amino groups.

Such Polyisocyanates are obtainable by methods known to the person skilled in the art, in the polyisocyanates with nonionic and / or ionic or nonionic or potentially ionic hydrophilizing compounds, respectively have at least one isocyanate-reactive group, are reacted.

Suitable ionically or potentially ionically hydrophilic compounds are, for. As mono- and dihydroxycarboxylic, mono- and diaminocarboxylic, mono- and Dihydroxysulfonsäuren, mono- and diaminosulfonic and mono- and Dihydroxyphosphonsäuren or mono- and Diaminophosphonsäuren and their salts such as dimethylolpropionic, dimethylolbutyric, hydroxypivalic, N- (2-aminoethyl) -β alanine, 2- (2-amino-ethylamino) -ethanesulfonic acid, ethylenediamine-propyl- or -butylsulfonic acid, 1,2- or 1,3-propylenediamine-β-ethylsulfonic acid, malic acid, citric acid, glycolic acid, lactic acid, glycine, alanine, Taurine, lysine, 3,5-diaminobenzoic acid, an addition product of IPDI and acrylic acid ( EP-A 0 916 647 , At game 1) and its alkali metal and / or ammonium salts; the adduct of sodium bisulfite with butene-2-diol-1,4, polyethersulfonate, the propoxylated adduct of 2-butenediol and NaHSO ₃ , e.g. B. described in the DE-A 2 446 440 (Pages 5-9, formula I-III) and compounds which can be converted into cationic groups, for. As amine-based, building blocks such as N-methyl-diethanolamine as hydrophilic structural components. Furthermore, cyclohexylaminopropanesulfonic acid (CAPS) such as. B. in the WO-A 01/88006 used as a compound.

Preferred ionic or potential ionic compounds are those which have carboxy or carboxylate and / or sulfonate groups and / or ammonium groups. Particularly preferred ionic compounds are those which contain carboxyl and / or sulfonate groups as ionic or potentially ionic groups, such as the salts of N- (2-aminoethyl) -β-alanine, of 2- (2-aminoethylamino) ethanesulfonic acid or the addition product of IPDI and acrylic acid ( EP-A 0 916 647 Example 1) and the dimethylolpropionic acid.

suitable nonionic hydrophilic compounds are z. B. polyoxyalkylene ethers, containing at least one hydroxy or amino group. These polyethers contain preferably a proportion of 30 wt .-% to 100 wt .-% relative on the total content of alkylene oxide units of ethylene oxide units.

Preferred nonionically hydrophilicizing compounds are compounds of the formula (I) H-Y'-XYR (I) in which
R is a monovalent hydrocarbon radical having 1 to 12 carbon atoms, preferably an unsubstituted alkyl radical having 1 to 4 carbon atoms,
X for a polyalkylene oxide chain having 5 to 90, preferably 20 to 70 chain members which at least 40 wt .-%, preferably at least 65 wt .-%, particularly preferably from 55 to 89 wt .-% based on the total content of alkylene oxide Units consist of ethylene oxide units and in addition to ethylene oxide units propylene oxide, butylene oxide or styrene oxide units may have, wherein propylene oxide units are preferred, and
Y ', Y is oxygen or also -NR'-, where R' = R or H.

Prefers The nonionic hydrophilicizing compounds correspond to the above mentioned type, wherein they have a number average molecular weight of at least 400 g / mol, preferably of at least 500 g / mol and especially preferably from 1200 to 4500 g / mol.

to Preparation of the invention essential hydrophilicized polyisocyanates can be known to those skilled in the aliphatic aliphatic, cycloaliphatic, araliphatic and aromatic polyisocyanates with more than one NCO group per molecule and one isocyanate content from 0.5 to 50 wt .-%, preferably 3 to 30 wt .-%, particularly preferably 5 to 25 wt .-% or mixtures thereof are used.

Examples suitable polyisocyanates are butylene diisocyanate, tetramethylene diisocyanate, Cyclohexane-1,3- and 1,4-diisocyanate, hexamethylene diisocyanate (HDI), 1-isocanato-3,3,5-trimethyl-5-isocyanato-methylcyclohexane (isophorone diisocyanate, IPDI), 2,4,4-trimethylhexamethylene diisocyanate, isocyanatomethyl-1,8-octane diisocyanate, Methylene bis (4-isocyanatocyclohexane), tetramethylxylylene diisocyanate (TMXDI) or triisocyanatononane (TIN, 4-isocyanatomethyl-1,8-octane diisocyanate) as well as their mixtures. In principle, aromatic are also suitable Polyisocyanates such as 1,4-phenylene diisocyanate, 2,4- and / or 2,6-toluene diisocyanate (TDI), diphenylmethane-2,4'- and / or 4,4'-diisocyanate (MDI), triphenylmethane-4,4'-diisocyanate or naphthylene-1,5-diisocyanate.

Next The above-mentioned polyisocyanates can also be higher molecular weight Derived products with uretdione, isocyanurate, urethane, allophanate, Biuret, Iminooxadiazindion- and / or Oxadiazintrionstruktur used become. Such secondary products are in a conventional manner the monomeric diisocyanates by those described in the prior art Modification reactions known.

Prefers are hydrophilized polyisocyanates or their mixtures with exclusively aliphatically or cycloaliphatically bonded isocyanate groups.

The hydrophilized polyisocyanates are particularly preferably based on hexamethylene diisocyanate, isophorone diisocyanate, the isomeric bis (4,4'-isocyanatocyclohexyl) methanes and also mixtures of the precursors called diisocyanates, wherein in the case of mixtures are those with at least 50 parts by weight of polyisocyanates based on hexamethylene diisocyanate are preferred.

incorporation the hydrophilized polyisocyanates in water and the subsequent Reaction with water to produce the nanourea dispersions is preferably carried out with mixing by an agitator or other types of mixing such as pumping, static mixers, spiked mixers, Jet disperser, rotor and stator or under influence from ultrasound.

in principle may during or after the dispersion nor a modification of NCO groups with isocyanate-reactive compounds such as primary or secondary amines or (poly) alcohols. Examples are ethylenediamine, 1,3-propylenediamine, 1,6-hexamethylenediamine, Isophoronediamine, 4,4'-diaminodicyclohexylmethane, hydrazine, 1,4-butanediol, 1,4-cyclohexanedimethanol, 1,6-hexanediol, trimethylolethane, trimethylolpropane, Glycerol, N-methylethanol and N-methylisopropanolamine, 1-amino-propanol or diethanolamine.

Prefers is the molecular ratio of NCO groups the hydrophilized polyisocyanates to water 1 to 100 to 1 to 5, more preferably 1 to 30 to 1 to 10.

in principle it is possible the hydrophilated polyisocyanates in one Portion into the water. Also is a continuous one Addition of the hydrophilicized polyisocyanate, for example via a period of 30 minutes to 20 hours possible.

Prefers is a portionwise addition, the number of portions being 2 to 50, preferably 3 to 20, particularly preferably 4 to 10, and the portions are the same or different in size can.

The Waiting time between the individual portions is typically 5 minutes to 12 hours, preferably 10 minutes to 8 hours, especially preferably 30 minutes to 5 hours.

Also possible is one over a period of 1 hour up to 24 hours, preferably 2 hours to 15 hours distributed continuous Addition of the hydrophilized polyisocyanate.

at the urea particle production is the boiler temperature 10 to 80 ° C, preferably 20 to 70 ° C and especially preferably 25 to 50 ° C.

Prefers is following the reaction of the hydrophilized polyisocyanate with water the reactor at internal temperatures of 0 ° C to 80 ° C, preferably 20 ° C to 60 ° C and especially preferably evacuated 25 ° C to 50 ° C. The evacuation takes place up to an internal pressure of 1 to 900 mbar, preferably 10 to 800 mbar, more preferably 100 to 400 mbar. The duration of this degassing following the actual reaction is 1 minute to 24 hours, preferably 10 minutes to 8 hours. A degassing is also due to temperature increase possible without evacuation.

Prefers simultaneously with the evacuation, the nanourea dispersion mixed, z. B. by stirring.

The Preparation of the aqueous nanourea dispersion can in the presence of catalysts.

suitable Catalysts are z. Ammonia, ferrous chloride, Zinc chloride, tin salts, tetraalkylammonium hydroxides, alkali hydroxides, Alkali alcoholates, alkali salts of long-chain fatty acids with 10 to 20 carbon atoms and optionally pendant OH groups, lead octoate or tertiary amines such as triethylamine, Tributylamine, dimethylbenzylamine, dicyclohexylmethylamine, dimethylcyclohexylamine, N, N, N ', N'-tetramethyl-diamino-diethyl ether, Bis (dimethylaminopropyl) urea, N-methyl- or N-ethylmorpholine, N, N'-dimorpholinodiethyl ether (DMDEE), N-cyclohexylmorpholine, N, N, N ', N'-tetramethylethylenediamine, N, N, N ', N'-tetramethylbutanediamine, N, N, N', N'-tetramethylhexanediamine-1,6, Pentamethyldiethylenetriamine, dimethylpiperazine, N-dimethylaminoethylpiperidine, 1,2-dimethylimidazole, N-hydroxypropylimidazole, 1-azabicyclo- (2,2,0) -octane, 1,4-diazabicyclo- (2,2,2) -octane (Dabco) or alkanolamine compounds, such as triethanolamine, triisopropanolamine, N-methyl- and N-ethyl-diethanolamine, Dimethylaminoethanol, 2- (N, N-dimethylaminoethoxy) ethanol or N-tris (dialkylaminoalkyl) hexahydrotriazine, z. N, N ', N-tris- (dimethylaminopropyl) -s-hexahydrotriazine. at Use of tert. Amines it is possible to use the catalyst after the production of the nanourea dispersion again separate, for example by distillation.

Prefers are Zinndioctoat, Zinndiethylhexoat, Dibuthylzinndilaurat or Dibutyldilauryltin mercaptide, 3-dimethyl-3,4,5,6-tetrahydropyrimidine, Tetramethylammonium hydroxide, triethylamine, sodium hydroxide, sodium methylate or potassium isopropylate. Particularly preferred catalyst is ammonia.

The Catalysts are in amounts of 0.01 to 8 wt .-%, preferably from 0.05 to 5 wt .-%, particularly preferably from 0.1 to 3 wt .-%, based on the total solids content of the resulting Dispersion used.

Of the Catalyst can with the hydrophilated polyisocyanates prior to introduction be mixed in the water or with the dispersing water or also only after the dispersion of the hydrophilized polyisocyanates be added in water. It is preferred that the catalyst the dispersing water before adding the hydrophilicized polyisocyanates to mix. It is also possible the catalyst in portions split up and at different times of the course of the reaction add.

at The preparation of nanourea dispersions can also Defoamers, surface-active detergents and other aids and additives are used. Also other additives from areas such as paint, sealant or adhesive formulation such as pigments or fillers be added.

Of the Proportion of nanourea particles relative to the polychloroprene dispersions is 0.1 to 50% by weight, preferably 0.5 to 20% by weight, Particularly advantageous is the stabilizing effect of nanourea particles, when combined with silica particles and / or zinc oxide particles be used. Silica particles and / or zinc oxide particles are preferably added as aqueous dispersions.

preferred Solid contents of the silica dispersions or zinc oxide dispersions are in each case 20 to 65 wt .-%, particularly preferably 45 to 60% by weight.

The average particle sizes of the silica dispersions are typically at 5 to 500 nm, preferably 8 to 100 nm, 9 to 50 nm is particularly preferably determined by means of laser correlation spectroscopy.

there already at zinc oxide concentrations of less than 2.5% by weight, preferably 0.25 wt .-% achieved excellent stabilization, which otherwise only by means of significantly higher amounts of zinc oxide would have been possible.

The preferred Siuliciumdioxidkonzentrationen the formulation is at 0 to 25 wt .-%, particularly preferably 0 to 15 wt .-% and completely particularly preferably 0 to 5 wt .-%.

In addition to nanourea particles and optionally ZnO and / or SiO ₂ particles, polychloroprene dispersions may also contain further additives such as emulsifiers, biocides, rheology additives, pigments, solvents, plasticizers, fillers, stabilizers, surfactants, metal oxides such as magnesium oxide, crosslinkers such as melamine resins, Be contained flow control agents, defoamers, dispersants and catalysts.

Especially For example, the polychloroprene dispersions contain at least one anti-aging agent based on oligofunctional secondary aromatic Amines and / or oligofunctional substituted phenols.

Examples

Provided Unless otherwise stated, all percentages are based on the weight. Unless otherwise noted, all analytical ones apply Measurements at temperatures of 23 ° C.

The indicated viscosities were determined by rotational viscometry according to DIN 53019 at 23 ° C with a rotational viscometer of the company Anton Paar Germany GmbH, Ostfildern, DE.

NCO contents were mentioned, unless explicitly stated otherwise, determined volumetrically according to DIN-EN ISO 11909.

The reported particle sizes were determined by laser correlation spectroscopy (Device: Malvern Zetasizer 1000, Malver Inst. Limited).

The Solid content was determined by heating a balanced sample to 120 ° C. At constant weight was by re-weighing the sample solids content is calculated.

Control for free NCO groups was performed by IR spectroscopy (band at 2260 cm ^-1 ).

The stability with respect to the elimination of HCl from the adhesive or coating film was determined in accordance with DIN 53381, method B, using a 763-PVC Thermomat (from Metrohm, Herisau, CH). In this case, 0.2 g of the cured adhesive film are weighed and heated in the thermomat at an air flow of 7 l / h to 180 ° C. As a measuring point for the determination of the HCl stability, the time of reaching 50 μS cm ^-1 conductivity was selected. The longer the time to reach the conductivity, the more stable the sample is against HCl elimination.

• Bayhydur^® VP LS 2336: Hydrophiliertes Polyisocyanat auf Basis von Hexamethylendiisocyanat, lösemittelfrei, Viskosität bei 23°C ca. 6800 mPas, Isocyanat-Gehalt ca. 16,2%, Bayer MaterialScience AG, Leverkusen, DE.
• Isofoam^® 16: Entschäumer, Petrofer-Chemie, Hildesheim, DE
• Dispercoll C 84: wässrig-kolloidale Dispersion eines Polymerisates des 2-Chlorbutadiens mit einem Polymeranteil von 55 Gew.-%, einer Viskosität von ca. 100 mPas und einem pH-Wert von ca. 13, Bayer MaterialScience AG, Lev, DE
• Dispercoll C VP LS 2325: wässrig-kolloidale Dispersion eines Polymerisates des 2-Chlorbutadiens mit einem Polymeranteil von 55 Gew.-%, einer Viskosität von ca. 100 mPas und einem pH-Wert von ca. 12, Bayer MaterialScience AG, Lev., DE
• Dispercoll S 3030: wässrige-kolloidale anionische Lösung von amorphen Siliziumdioxid einem Feststoffanteil von 30 Gew.-% und einem pH-Wert von ca. 10, Bayer MaterialScience AG, Lev., DE
• Borchers VP 9802: wässrige Zinkoxid-Dispersion (Feststoffgehalt 50%, mit entionisiertem Wasser auf 25% verdünnt), Borchers AG, Langenfeld, DE
• Rhenofit DDA 50-EM: wässrige Emulsion eines Alterungsschutzmittels (Antioxidanz) auf Basis eines Diphenylamin-Derivates, Festgehalt 50 Gew.-%, Rheinchemie, Mannheim, DE Die anderen Chemikalien wurden im Feinchemikalienhandel bei Sigma-Aldrich GmbH, Taufkirchen, DE bezogen.

The sedimentation behavior of the formulations was determined on the basis of DIN 38409 part 9. For this purpose, a volume of 1 L of the formulations was stored for 72 hours at room temperature in a sedimentation glass (according to DIN 12672 Part 2). Subsequently, the settling volume was determined.

• Bayhydur ^® VP LS 2336: Hydrophilized polyisocyanate based on hexamethylene diisocyanate, solvent-free, viscosity at 23 ° C ca. 6800 mPas, isocyanate content approx 16.2%, Bayer MaterialScience AG, Leverkusen, DE.
• Isofoam ^® 16: defoamers, Petrofer chemistry, Hildesheim, DE
• Dispercoll C 84: aqueous-colloidal dispersion of a polymer of 2-chlorobutadiene with a polymer content of 55% by weight, a viscosity of about 100 mPas and a pH of about 13, Bayer MaterialScience AG, Lev, DE
• Dispercoll C VP LS 2325: aqueous-colloidal dispersion of a polymer of 2-chlorobutadiene with a polymer content of 55% by weight, a viscosity of about 100 mPas and a pH of about 12, Bayer MaterialScience AG, Lev., DE
• Dispercoll S 3030: aqueous colloidal anionic solution of amorphous silica having a solids content of 30% by weight and a pH of about 10, Bayer MaterialScience AG, Lev., DE
• Borchers VP 9802: aqueous zinc oxide dispersion (solids content 50%, diluted to 25% with deionized water), Borchers AG, Langenfeld, DE
• Rhenofit DDA 50-EM: aqueous emulsion of an anti-aging agent (antioxidant) based on a diphenylamine derivative, solids content 50% by weight, Rheinchemie, Mannheim, DE The other chemicals were obtained from the fine chemicals trade at Sigma-Aldrich GmbH, Taufkirchen, DE.

The Specification phr denotes that used on 100 parts of binder solid Dosing. Only the solids content is used of the starting materials.

Example 1 Preparation of an aqueous Nanourea dispersion

To a solution of 2.23 g of ammonia water (containing 25 wt .-% of ammonia) in deionized water 812 g were added at 30 ° C with vigorous stirring 136 g Bayhydur ^® VP LS 2336, and then 0.02 g Isofoam ^® 16 and further stirred. After 2, 4 and 6 hours, a further 136 g each Bayhydur ^® VP LS 2336, and then 0.02 g per Isofoam ^® 16 were added and then stirred for a further 4 hours at 30 ° C. Thereafter, stirring was continued at 200 mbar vacuum and 30 ° C for 3 hours and bottled the resulting dispersion.

The resulting white aqueous dispersion had the following properties: Particle size (LKS): 77 nm Viscosity (viscometer, 23 ° C): <50 mPas pH (23 ° C): 6.9

Example 2 Preparation of the samples and Results of HCl Stability Determination

to Preparation of the adhesive or coating agent were the starting materials according to Table 1 in a beaker with the help a paddle stirrer mixed together.

All prepared formulations contained 2 phr of the anti-aging agent Rhenofit DDA 50 EM.

To complete mixing, the formulations were still 12 hours left.

After that were cast in a suitable form films, which after complete Drying to have a thickness of about 1 mm. The film drying was at 23 ° C / 50% RH.

The HCl stability was determined for the following adhesives or coating compositions: TABLE 1 Comparative example A B C composition Dispercoll C 84 + 1 phr ZnO Dispercoll C 84 + 2 phr ZnO Dispercoll C 84 + 3 phr ZnO HCl stability 278 min 337 min 340 min Table 2: Inventive example D e F composition Dispercoll C 84 + 1 phr nanourea Dispercoll C 84 + 5 phr nanourea Dispercoll C 84 + 20 phr nanourea HCl stability 218 min 307 min 365 min

Tables 1 and 2 show that even small dosages of the nanourea have a stabilizing effect on the binder and adhesive films. A replacement of zinc oxide by nano-urea is possible. Table 3: Comparative example A G composition Dispercoll C 84 + 1 phr ZnO Dispercoll C VP LS 2325 + 1 phr ZnO HCl stability 278 min 415 min Table 4: Inventive example H I composition Dispercoll C 84 + 1 phr ZnO + 5 phr nanourea Dispercoll C VP LS 2325 + 1 phr ZnO + phr nanourea HCl stability 416 min 546 min

• a) Vergleichsbeispiel b) erfindungsgemäßes Beispiel

Tables 3 and 4 show that very strong increases in HCl stability are achieved by combining small amounts of zinc oxide with nanourea. Thus, formulation H according to the invention achieves an HCl stability increased by 50% compared to comparative example A, formulation I according to the invention in comparison with comparative formulation G at least an increase of 31%. Table 5: example Yes) Kb) lb) composition Dispercoll C 84 + 0.24% ZnO Dispercoll C 84 + 0.24% ZnO + 4.7% nanourea Dispercoll C 84 + 0.24% ZnO + 8.4% nanourea HCl stability 239 min 416 min 467 min

• a) Comparative Example b) Example according to the invention

• a) Vergleichsbeispiel b) erfindungsgemäßes Beispiel

In Table 5, the content of zinc oxide in terms of the total formulation was reported to show that even dosages of less than 0.25% by weight of zinc oxide based on the total formulation, in combination with small amounts of nano-urea, achieve excellent HCl stability. Thus, the addition of nanourea allows the formulation of label-free adhesives and coating materials with sufficiently high HCl stability. Table 6: example Ma) Nb) Oa) Pb) composition Dispercoll C84 + 3.5 phr ZnO Dispercoll C84 + 20 phr nanourea Dispercoll VPLS 2325 + 3.5 phr ZnO Dispercoll VPLS 2325 + 20 phr nanourea amount of sediment 17.5 mL - 24.0 mL -

• a) Comparative Example b) Example according to the invention

table Figure 6 shows the excellent storage stability of formulations with nanourea. Even at high doses of nanourea and in combination with sedimentation-sensitive dispersions (Ex. P) shows up in the nanourea-containing formulations no settled material. In contrast, those in the comparative examples formed sediments not only because of their amount disturbing, they are also very difficult to even redispersible.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• WO 2004/106422 [0007]
• WO 02/24825 [0015]
• - DE 3002734 A [0015]
• - US 5773544 A [0015]
• - EP 0916647 A [0022, 0023]
• - DE 2446440 A [0022]
• WO 01/88006 A [0022]

Cited non-patent literature

• - "Handbook of Adhesives", Irving Skeist, Chapman, Hall, New York, 3rd Ed. 1990, Part 15, Page 301 [0003]
• - R. Musch et al., Adhesives Age, January 2001, page 17, "Dispercoll® C Spray-Mixing Adhesives for Foam Bonding" [0003]
• - Technical Information of Bayer AG, No. KA-KR-0001d / 01 / 05.96 [0003]

Claims (7)

Use of nanourea particles as stabilizers for aqueous polychloroprene dispersions. Use according to claim 1, characterized characterized in that improved stability against Phase separation of the dispersions and better protection against Aging phenomena from these dispersions produced adhesive seams and discoloration of the bonded substrates by HCl action is reached. Use according to claim 1 or 2, characterized in that the nanourea particles intramolecularly urea groups cross-linked organic particles with a middle Particle size determined by means of laser correlation spectroscopy (LKS) measurements from 20 to 500 nm. Use according to one of the claims 1 to 3, characterized in that the nanourea particles by dispersing hydrophilized polyisocyanates in water and subsequent reaction of thereby formed amino groups with free NCO groups of the polyisocyanates are formed. Use according to claim 4, characterized characterized in that the hydrophilized polyisocyanates are nonionic are hydrophilic and exclusively aliphatic or having cycloaliphatic bound isocyanate groups. Use according to one of the claims 1 to 5, characterized in that the proportion of nanourea particles based on the polychloroprene dispersions 0.5 to 20 wt .-% is. Use according to one of the claims 1 to 6, characterized in that the nanourea particles in combination with silica particles and / or zinc oxide particles be used.