WO2002009863A2

WO2002009863A2 - Microcapsule, method for producing the same, and the use thereof in adhesives

Info

Publication number: WO2002009863A2
Application number: PCT/EP2001/008764
Authority: WO
Inventors: Frank Meier; Thomas Huver; Werner Jüttner
Original assignee: Henkel Kommanditgesellschaft Auf Aktien
Priority date: 2000-08-02
Filing date: 2001-07-28
Publication date: 2002-02-07
Also published as: DE10037729A1; AU2001291696A1; WO2002009863A3

Abstract

The invention relates to a microcapsule that consists of a capsule and a capsule content. The capsule coat comprises at least one water-soluble or water-dispersible polymer that has a molecular weight of more than 3000 and the capsule content comprises at least two functional groups X that are reactive to isocyanate groups or epoxy groups or carboxyl groups, or a catalyst that accelerates the reaction between isocyanate groups or epoxy groups or carboxyl groups and a compound with at least two functional groups X that are reactive to isocyanate groups or epoxy groups or carboxyl groups, or both. The invention further relates to a method for producing such microcapsules, to adhesives that contain such microcapsules and to the use of the inventive microcapsules in the production of adhesives.

Description

Microcapsule, process for its preparation and its use in

adhesives

The present invention relates to a microcapsule consisting of a capsule and a capsule content, the capsule shell having at least one water-soluble or water-dispersible polymer with a molecular weight of more than 3000 and the capsule content having at least one compound having at least two functional groups X which are reactive towards isocyanate groups or epoxy groups or carboxyl groups or a catalyst which accelerates the reaction between isocyanate groups or epoxy groups or carboxyl groups and a compound having at least two functional groups X which are reactive towards isocyanate groups or epoxy groups or carboxyl groups. Furthermore, the present invention relates to a method for producing such microcapsules, adhesives containing such microcapsules and the use of the microcapsules according to the invention in the production of adhesives.

Surface coating compositions, in particular adhesives, often contain several components which, after the surface coating composition has been applied, react with one another to form covalent compounds and thus cause the surface coating composition to harden. The various components can be present, for example, in the surface coating composition in such a way that curing takes place only at higher temperatures, while at normal ambient temperatures, such as may prevail when the surface coating composition is applied, there is no reaction of the components with one another. However, surface coating compositions of this type, usually referred to as IC systems, often require very high temperatures in order to cure. However, this limits the use of such IC systems. in that certain, in particular heat-sensitive, substrates cannot be processed with such a surface coating agent.

In contrast, there are surface coating agents which consist of two separate components (so-called 2K systems). These two components are usually mixed shortly before the planned use of the surface coating agent. While such 2K systems allow curing at ambient temperature or only slightly elevated temperatures, they require a mixing process before use, in which defined quantities of the two components must be mixed with one another as precisely as possible. In practice, however, the required mixing ratios are often not exactly adhered to in the case of such mixtures, as a result of which the performance of the surface coating is impaired with regard to optimal curing. In addition, such 2K systems generally have to be processed shortly after mixing, otherwise the progressive hardening of the mixed components makes further processing difficult or impossible. This is particularly disadvantageous when larger amounts of surface coating agent are to be used. In this case, several small portions have to be prepared repeatedly for use, which considerably increases the effort involved in processing such systems.

In order to remedy these disadvantages, systems have been described in the prior art which contain one of the two components of a two-component system in deactivated form.

EP-A 0 193 068 relates to an IC epoxy resin composition which contains an epoxy resin with an average of at least two epoxy groups per molecule and a powdered amino compound. The amino compound was with provide a coating which adheres to the powder particle either by adhesion or by covalent bond between the coating and powder particle. The coating is effected by applying a compound which has at least one isocyanate group, a carboxyl group, an anhydride group or an acid chloride group. However, the components described have the disadvantage that their preparation comprises the processing of toxic compounds and, in addition, part of the coated compound which contributes to curing is no longer available due to reaction with the coating during the curing process.

EP-A 0 547 379 relates to an adhesive which contains a diamine and an isocyanate, with either the diamine or the isocyanate being enclosed in a microcapsule. A disadvantage of the described adhesives is that the predominantly wax-like materials used for the encapsulation can have a negative effect on the adhesive strength of the adhesive. Furthermore, the microcapsules used in the publication are generally very large. This severely limits the use of the microcapsules described for adhesive joints with a gap width below this size value, for example. Furthermore, the described microcapsules sediment slightly, which makes the adhesive contained inhomogeneous. As a result, bonding is not reproducible or even fails.

There was therefore a need for two IC systems containing reactive components which are suitable for surface coating, preferably as an adhesive, one of the reactive components or a catalyst which triggers the reaction at a certain temperature being present in encapsulated form as a microcapsule. There was also a need for microcapsules which can be produced in the encapsulation without the use of toxic compounds, with a reduced use of such compounds, and which do not adversely affect the adhesive force. Accordingly, the object of the present invention was to provide such microcapsules, to provide a method for producing such microcapsules and to provide an adhesive which contains such microcapsules.

The objects on which the invention is based are achieved by microcapsules, processes for their production and by adhesives as described in the text below.

The present invention therefore relates to a microcapsule, consisting of a capsule shell and a capsule content, the capsule shell comprising at least one water-soluble or water-dispersible polymer with a molecular weight of more than 3000 and the capsule content at least one compound having at least two functional groups which are reactive toward isocyanate groups or epoxy groups or carboxyl groups Groups X or a catalyst which accelerates the reaction between isocyanate groups or epoxy groups or carboxyl groups and a compound having at least two functional groups X which are reactive toward isocyanate groups or epoxy groups or carboxyl groups, or both.

In the context of the present invention, a “microcapsule” is understood to mean a structure which has a capsule content and a capsule shell. In the context of the present invention, such a “microcapsule” has a diameter of less than approximately 100 μm, for example less than 50 μm, less than 30 μm or less than 10 μm. In the context of a preferred embodiment of the present invention, at least about 95% of the microcapsules according to the invention have a diameter of less than about 30 μm. The specified diameters refer to measured values for partial diameter as can be obtained by means of customary methods for determining particle diameters. Suitable measuring methods are, for example, sieving methods, light scattering, electron microscopy, light microscopy, scanning electron microscopy or sedimentation methods. This definition does not conflict with the fact that two or more microcapsules have assembled to form an aggregate. The decisive factor in the present case is the particle size of the individual microcapsules participating in the aggregate.

The term “molecular weight” in the context of the present text, insofar as it is applied to polymeric or oligomeric compounds, refers to the weight average molecular weight (M _w ), as determined by GPC under suitable conditions, for example based on a polystyrene standard , can be determined.

Within the scope of the present invention, a microcapsule as a capsule morphology can have a typical capsule-like structure, in which an essentially closed casing made of casing material encloses an essentially homogeneous core as the capsule content. According to the invention, however, it is also possible for a microcapsule according to the invention to have a shell which encloses an inhomogeneous core. An "inhomogeneous core" is understood to mean the finding that the capsule content is present in several domains inside the capsule, that is to say that several regions with capsule content are spatially separated from one another by shell material within the microcapsule.

The microcapsules according to the invention can essentially have any spatial shape. For example, spherical, square, cuboid, cylindrical or conical spatial shapes are suitable. In the context of a preferred embodiment of the present invention, however, the microcapsules have an essentially spherical three-dimensional shape. In a first embodiment of the present invention, the microcapsules according to the invention have at least one compound with at least two functional groups X which are reactive toward isocyanate groups or epoxy groups or carboxyl groups. Suitable functional groups X are, for example, OH, NH ₂ , NHR ¹ , SH or COOH groups, where R ^{1 is} a linear or branched, saturated or unsaturated alkyl radical having 1 to about 24 carbon atoms. A compound which is suitable as capsule content in the context of the present invention can have only one type of functional group X, ie all functional groups X on a molecule of the corresponding compound are identical. However, it is also possible within the scope of the present invention that the capsule content contains a compound which has two or more functional groups X, at least two of the functional groups X of a compound being different. For example, it is possible within the scope of the present invention to use a compound as capsule content which has, for example, at least one OH group and at least one NH group. A microcapsule according to the invention can have only one compound as a capsule content within the scope of the present invention which carries a functional group X. However, it is also provided according to the invention that a microcapsule according to the invention contains two or more different compounds as capsule content. Such different compounds can differ in the number or type of the functional groups X or in the constitution carrying the functional group X or in both.

In the context of a preferred embodiment of the present invention, a microcapsule according to the invention contains 1, 2 or 3 different compounds as capsule content.

A compound suitable as capsule content can be used in the context of the present Invention only have two functional groups X. However, it is also possible for the capsule content of a microcapsule according to the invention to have a compound which has more than two functional groups X, for example three, four or five functional groups X. The number of functional groups X of such a compound can be an integer, for example if the capsule content contains only one type of compound with a functional group X. However, it is also possible for the number of functional groups X to be a number between two even numbers, for example 2.1, 2.5, 2.8 or the like. This is particularly the case if the capsule content contains a mixture of two or more compounds with a different number of functional groups X. In such a case, the capsule content can contain, for example, compounds which differ only in the number of functional groups X.

Compounds with at least two functional groups X suitable as capsule content can be present in solid or in liquid form. However, it is necessary in the context of the present invention that corresponding compounds have only a low solubility in water or are not water-soluble. In the context of a preferred embodiment of the present invention, suitable capsule contents have a water solubility of less than 2 g / 1, for example less than 1 g / 1 or less than 0.5 g / 1 or less than 0.1 g / 1 on.

In the context of a preferred embodiment of the present invention, a microcapsule according to the invention has at least one compound as capsule content which carries at least one amino group as functional group X. Suitable amines are, for example, ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine or diethylaminopropylamine, aromatic amines such as m-phenylene diamine, diaminodiphenyl methane, diaminodiphenyl sulfone, bisaminomethyl diphenylene methane, o-phenylene diamine, triaminobenzene Aminobenzylamine, 2,4-diaminotoluene, benzidine, 4,4'-diaminodiphenylmethane, p, p-bisaminomethylbiphenyl, p, p-bisaminomethyldiphenylenemethane, m-phenylenediamine, p-phenylenediamine, 4-aminodiphenylamine, hydrazides such as adipate diamine dihydrazide, suazidine dihydrazide , Terephthalaldihydrazide, dicyandiamide, imidazole compounds such as imidazole, 2-methylimidazole, 2-undecylimidazole, 4-methylimidazole, 2-phenylimidazole, 2-heptadecylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoimidazole, 2-ethylimidazole, 2-ethylimidazole, 2-ethylimidazole, 2-ethylimidazole, 2-ethylimidazole, 2-ethylimidazole, 2-ethylimidazole, 2-ethylimidazole, 2-ethylimidazole, 2-ethylimidazole, 2-ethylimidazole, 2-ethylimidazole, 2-ethylimidazole, 2-ethylimidazole, 2-ethylimidazole, 2-ethylimidazole, 2-ethylimidazole, 2-ethylimidazole, 2-ethylimidazole, 2-ethylimidazole, 2-trimimidazole -Isopropylimidazole, 2-dodecylimidazole, 2-ethyl-4-methylimidazole and imidazoline compounds such as 2-methylimidazoline, 2-phenylimidazoline, 2-undecylimidazoline or 2-heptadecylimidazoline or a mixture of two or more of the above-mentioned amino compounds.

The following amines can also be used as amines in the context of the present invention: isophoronediamine, m-xylylenediamine, 2,2,4-trimethylhexamethylenediamine, 4,4'-trimethylene dipiperidine, 1,3-di (4-piperidyl) propane, 1,6 -Diaminohexane, 1,7-diaminoheptane, 1,11-diaminodecane, 1,12-diaminododecane, 4,4-diaminodicyclohexylmethane, 1,4-

Diazabicyclo [2.2.2] octane (DABCO) and polymeric di- or polyamines such as amino groups, polyesters, polyurethanes or polyethers, in particular under the trade name Jeffamine ^® from Huntsman Coorp. available polyalkylene glycols bearing amino groups.

In the context of a preferred embodiment of the present invention, the capsule content contains 4-aminodiphenylamine or 4,4'-diaminodiphenylmethane or a mixture thereof.

However, the microcapsules according to the invention can also be used in adhesive systems which already contain a reactive binder system, reactive compounds which are present next to one another. Such binding Agent systems can contain, for example, at least two compounds which are fundamentally reactive with one another with an increase in molecular weight, for example epoxy compounds and polyols. However, the reactivity of the binder system is severely restricted at the processing temperature of the adhesive system, so that essentially no reaction takes place. The reaction of such binder systems can, however, be started or accelerated by suitable catalysts. In the context of such an embodiment of the present invention, the capsule content of the microcapsules according to the invention contains a catalyst or a mixture of two or more catalysts which enable the reaction of the binder system and thus the adhesive to set.

Suitable catalysts are, for example, tertiary amines, e.g. Triethylamine, 1,4-diazabicyclo [2,2,2] octane (= DABCO), dimethylbenzylamine, bis-dimethylaminoethyl ether and bis-memylaminomethylphenol. Particularly suitable are 1-methyl-imidazole, 2-methyl-1-vinylimidazole, 1-allylimidazole, 1-phenylimidazole, 1,2,4,5-tetramethylimidazole, 1- (3-aminopropyl) imidazole, pyrimidazole, 4- Dimemylamino-pyridine, 4-pyrrolidinopyridine, 4-morpholino-pyridine, 4-methylpyridine and dimorpholinodiethyl ether.

Organotin compounds can also be used as catalysts. These are understood to mean compounds which contain both tin and an organic radical, in particular compounds which contain one or more Sn — C bonds. Organotin compounds in the broader sense include, for example, salts such as tin octoate and tin stearate. The tin compounds in the narrower sense include above all compounds of tetravalent tin of the general formula R _{n +} ιSnZ _3-n , where n stands for a number from 0 to 2, R stands for an alkyl group or an aryl group or both and Z finally for oxygen -, sulfur or nitrogen compound or a mixture of two or more thereof. R expediently contains at least 4 carbon atoms, in particular at least 8. The upper limit is usually 12 C atoms. Z is preferably an oxygen compound, ie an organotin oxide, hydroxide, carboxylate or an ester of an inorganic acid. However, Z can also be a sulfur compound, that is to say an organotin sulfide, thiolate or a thiosate. In the case of the Sn-S compounds, thioglycolic acid esters are particularly suitable, for example compounds with the following radicals:

-S-CH ₂ -CH ₂ -CO-O- (CH ₂ ) ₁₀ -CH ₃ or

-S-CH ₂ -CH ₂ -CO-O-CH ₂ -CH (C ₂ H ₅ ) -CH ₂ -CH ₂ -CH ₂ -CH ₃ .

Another preferred class of compounds are the dialkyltin (IN) carboxylates (Z = O-CO-R ^I ). The carboxylic acids have 2, preferably at least 10, in particular 14 to 32, carbon atoms. Dicarboxylic acids can also be used. Suitable acids are, for example, adipic acid, maleic acid, fumaric acid, terephthalic acid, phenylacetic acid, benzoic acid, acetic acid, propionic acid and in particular caprylic, capric, lauric, myristic, palmitic and stearic acid. For example, dibutyltin diacetate and dilaurate and dioctyltin diacetate and dilaurate are particularly suitable.

Tin oxides and sulfides and thiolates are also suitable in the context of the present invention. Specific compounds are: bis (tributyltin) oxide, dibutyltin didodecylthiolate, dioctyltin dioctylhiolate, dibutyltin bis (2-ethyl-hexyl thioglycolate), 2-ethyl-octyltin (2-ethyl-hexyl-ethyl-2-ethylhexyl) -glycol-ethyl-2-ethylhexyl ester -ethylhexoate), dibutyltin bis (tnioethylene-glycolaurate), dibutyltin sulfide, dioctyltin sulfide, bis (tributyltin) sulfide, dibutyltin bis (thioglycolic acid-2-ethylhexyl ester), dioct ltin-glycol-bis (thioethylene glycol) -thioethylene glycol-bis (thioethylene glycol) 2-ethylhexoate and di-tin-bis (2-ethyl-thiolatoacetic acid), bis (S, S-methoxycarbonyl-etiιyl) tin-bis (2-ethylhexyl-thiolatoacetate), bis (S, S-acetyl-ethyl) tin- bis (2-ethylhexyl thiolatoacetic acid), tin (II) octyl_hiolate and tin (II) thioethylene glycol 2-ethylhexoate.

The following may also be mentioned: dibutyltin diethylate, dihexyltin dihexylate, dibutyltin diacetylacetonate, dibutyltin diethylacetylacetate, bis (butyldichlorotin) oxide, bis (dibutylchlorotin) sulfide, tin (II) phenolate, tin (II) and diacetyl acetylene dibenzyl acyl dicyl acyl acyl acetylate Benzoylacetone, ethyl acetoacetate, n-propyl acetoacetate, α, α '- diphenylacetoacetic acid ethyl ester and dehydroacetoacetic acid.

In the context of a further embodiment of the invention, the capsule content can contain, for example, a compound having functional groups X, as described above, or a mixture of two or more such compounds and a catalyst, as described above, or a mixture of two or more such catalysts.

In addition to the above-mentioned compounds with functional groups X or a catalyst or a mixture of a compound with functional groups X and a catalyst or a mixture of two or more compounds with functional groups X and a catalyst or a mixture of two or more compounds with Functional groups X and a mixture of two or more catalysts, the capsule content can have further additives. These include plasticizers, antioxidants, stabilizers, UV protection, dyes, fragrances, pigments and the like.

For example, plasticizers based on phthalic acid are used as Weimacher, in particular dialkyl phthalates, phthalic acid esters containing about 6 to about 12 carbon atoms being preferred as plasticizers. pointing, linear alkanol were esterified. Dioctyl phthalate is particularly preferred.

Also suitable as plasticizers are benzoate plasticizers, for example sucrose benzoate, diethylene glycol dibenzoate and / or diethylene glycol benzoate, in which about 50 to about 95% of all hydroxyl groups have been esterified, phosphate plasticizers, for example t-butylphenyldiphenylphosphate, polyethylene glycols and their derivatives of, for example, diphenene ly (ethylene glycol), liquid resin derivatives, for example the methyl ester of hydrogenated resin, vegetable and animal oils, for example glycerol esters of fatty acids and their polymerization products.

Stabilizers or antioxidants which can be used as additives in the context of the invention include hindered phenols of high molecular weight (M _n ), polyfunctional phenols and sulfur- and phosphorus-containing phenols. Phenols which can be used as additives in the context of the invention are, for example, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene; Pentaerythritol tetra-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate; n-octa-decyl-3,5-di-tert-butyl-4-hydroxyphenyl) propionate; 4,4-methylenebis (2,6-di-tert-butyl-phenol); 4,4-thiobis (6-tert-butyl-o-cresol); 2,6-di-tert-butylphenol; 6- (4-hydroxyphenoxy) -2,4-bis (n-octylthio) -l, 3,5-triazine; Di-n-octadecyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate; 2- (n-octylthio) ethyl 3,5-di-tert-butyl 4-hydroxybenzoate; and Sorbithexa [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] as a photo-stabilizers are for example those suitable under the name ^® Thinuvin: are commercially available (manufactured by Ciba Geigy).

Further additives can be included in the microcapsules according to the invention in order to vary certain properties. These include, for example, dyes such as titanium dioxide, fillers such as talc, clay and the like. be.

In addition to the capsule content described above, a microcapsule according to the invention also has a capsule shell. The capsule shell contains at least one water-soluble or at least water-dispersible polymer which has a molecular weight of more than 3,000.

In the context of the present invention, a water-soluble polymer is understood to mean a polymer which forms an essentially molecularly disperse solution in water. In the context of the present invention, a water-dispersible polymer is understood to mean a polymer which forms a stable dispersion in water, if appropriate in the presence of a suitable emulsifier. In the context of a preferred embodiment of the present invention, the capsule shell contains a polymer which is either water-soluble or self-dispersible in water. In the context of the present invention, a polymer which is self-dispersible in water is understood as a polymer which forms a dispersion in water essentially without the addition of an emulsifier.

Polymers suitable as part of the capsule shell in the context of the present invention preferably have one or more OH groups or one or more COOH groups or sulfonic acid groups or both. Suitable polymers are, for example, cellulose or cellulose ethers such as carboxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxyalkyl cellulose, in particular hydroxyethyl cellulose or their mixed ethers, such as methyl hydroxyethyl or hydroxypropyl cellulose, carboxymethyl hydroxyethyl cellulose or ethyl hydroxyethyl cellulose or a mixture of two or more of the polymers mentioned. Also suitable are, for example, polymers which are formed by polymerizations of vinyl acetate and subsequent partial or complete saponification Let some or all of the acetate groups be preserved. These include in particular polyvinyl alcohols which still have about 1 to about 70% acetate groups. Copolymers are also suitable, in the production of which at least one further monomer was used in addition to vinyl acetate and whose vinyl acetate portion was wholly or partially saponified. Corresponding copolymers can be used as statistical copolymers or as block copolymers. Suitable comonomers are, for example, acrylic acid, methacrylic acid, ethylene, styrene or α-methylstyrene, where appropriate block copolymers can be based on two or more of the monomers mentioned. In a further preferred embodiment of the present invention, a styrene / vinyl acetate copolymer is used as part of the capsule shell, the vinyl acetate units of which are saponified to at least 60%, preferably to at least 80% or 90%. If polyvinyl alcohols are used as a component of the capsule shell, polyvinyl alcohol with a degree of saponification of about 70 to about 90% is particularly suitable.

Also suitable are the sulfonic acid derivatives of the abovementioned compounds, for example α-polystyrene sulfonate with a molecular weight (M _w ) of about 50,000 to about 100,000. Also suitable are those in “Advances in Polymer Science, 136, A. Prokop, D. Hunkeler et al., Watersoluble Polymers for Imunoisolation, p. 5, Table 2 ff, Springer-Verlag, Berlin / Heidelberg / Νew York, 1998 "described, water-soluble polymers, to which express reference is made here and which are regarded as part of the present disclosure.

Mixtures of two or more polymers are also suitable, at least one of the polymers present in the mixture having OH groups. In a preferred embodiment of the present invention, for example, mixtures of hydrophobic and hydrophilic polymers are used, in particular mixtures containing styrene and at least one hydrophilic Polymer, for example cellulose or a cellulose derivative or polyvinyl alcohol. In a further preferred embodiment, polymer mixtures are used as material for the capsule shell, which were produced by polymerizing styrene in the presence of a hydrophilic polymer, for example in the presence of cellulose or in the presence of a cellulose ether or in the presence of polyvinyl alcohol.

The polymers contained in the capsule shell have a molecular weight of at least about 3000. In the context of a preferred embodiment of the present invention, the molecular weight of the polymers contained in the capsule shell is at least about 5000, for example at least about 10,000. The upper limit for the molecular weight of the polymers contained in the capsule shell is about 1,000,000, but preferably less. Suitable upper limits for corresponding molecular weights are, for example, 200,000, 100,000 or approximately 50,000. If, for example, a cellulose ether is used as a component of the capsule shell, a molecular weight of about 15,000 to about 40,000 has proven successful. If, for example, a polyvinyl alcohol is used as a component of the capsule shell, the molecular weight should be about 10,000 to about 35,000.

The capsule shell can contain, for example, one of the abovementioned polymers, but it is also possible within the scope of the present invention that the capsule shell contains two or more of the abovementioned polymers. The proportion of water-soluble or water-dispersible polymers in the capsule shell is at least about 30% by weight or at least about 40% by weight. In the context of a preferred embodiment of the present invention, the proportion of water-soluble or water-dispersible polymers in the capsule shell is at least about 50% by weight or 60% by weight, for example at least about 70% by weight, 80% by weight, 90% by weight .-% or even 100 wt .-%. The microcapsules according to the invention can be obtained by spray drying an aqueous solution or dispersion of the constituents forming the capsule.

The present invention therefore also relates to a process for the preparation of a microcapsule according to the invention, in which an aqueous solution or dispersion of at least one water-soluble or water-dispersible polymer with a molecular weight of more than 3000, in which at least one compound having at least two isocyanate groups or epoxy groups or Carboxyl group-reactive functional groups X or at least one catalyst or a mixture of two or more of them, dispersed, is subjected to spray drying, a microcapsule consisting of a capsule shell and a capsule content being formed.

In principle, all spray drying processes known to the person skilled in the art are suitable for producing the microcapsules according to the invention. In a spray drying process, the aqueous solution or dispersion which contains the components of the microcapsule according to the invention is sprayed together with a hot air stream, the aqueous phase or all components which are volatile in the air stream evaporating. This produces microcapsules in which the compound having at least two functional groups X which are reactive toward isocyanate groups or epoxy groups or carboxyl groups, or a mixture of two or more such compounds, or a catalyst or a mixture of two or more catalysts, or a mixture of a compound with at least two functional groups X reactive to isocyanate groups or epoxy groups or carboxyl groups and a catalyst or a mixture of two or more compounds having at least two functional groups X reactive to isocyanate groups or epoxy groups or carboxyl groups and a catalyst or a mixture of two or more compounds having at least two functional groups X reactive towards isocyanate groups or epoxy groups or carboxyl groups and a mixture consisting of two or more catalysts as capsule content is essentially completely enveloped by the capsule shell, which contains at least one water-soluble or water-dispersible polymer with a molecular weight of more than 3000.

In order to achieve the most complete possible encapsulation of the capsule contents, it is advantageous if the capsule contents are present in the finest possible distribution in the dispersion used for spray drying. In the context of a preferred embodiment of the present invention, the capsule content should be distributed in such a way that the average maximum particle size of the compounds provided as capsule content is at most about 10 to 15 μm, but preferably less. In the context of the present invention, the average maximum particle size for solids is understood to mean the average particle size of the solid particles. If the capsule content or at least parts of the capsule content is present as a liquid, the maximum particle size is understood to mean the average drop size of the liquid in the dispersion.

The average maximum particle size is preferably approximately 0.1 to approximately 15 μm, in particular approximately 0.5 to approximately 12 μm or to approximately 13 μm, for example approximately 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 μm.

If the polymer forming the shell or a component of the shell is in the form of a dispersion, the average particle size of the polymer particles in the dispersion is at most about 50 μm, but is preferably less.

In a preferred embodiment of the present invention, the spray drying is carried out in such a way that the temperature of the aqueous dispersion or solution is about 5 to about 70 ° C., for example about 10 to about 50 ° C. or about 15 to about 30 ° C. The temperature of the air stream is preferably adjusted such that it is about 100 to about 200, for example about 120 to about 160 ° C.

It may be advantageous if the dispersion intended for spray drying is subjected to a treatment prior to spray drying which reduces the particle size or, where appropriate, disaggregates aggregates of two or more particles present in the dispersion. A suitable pretreatment process is, for example, ultrasound treatment. For this purpose, the dispersion intended for spray drying is treated for a period of about 0.5 to about 200, for example about 1 to about 50 minutes in an ultrasonic bath at a temperature of about 10 to about 50 ° C., for example at about 15 to about 25 ° C. , Further suitable pretreatment processes are, for example, the treatment of the dispersion intended for spray drying in the Ultra Turrax in the colloid mill, in the homogenizer, in a mixing turbine or in a static mixer.

The dispersion subjected to spray drying contains about 0.1 to about 40% by weight, in particular about 0.5 to about 30% by weight, of a water-soluble or water-dispersible polymer or a mixture of two or more such polymers. If, for example, a cellulose ether or a mixture of two or more cellulose ethers is used as the filler, the proportion of cellulose ether or cellulose ethers in the dispersion used for spray drying is about 0.5 to about 5, in particular about 1, in the context of a preferred embodiment of the present invention up to about 4% by weight. If the dispersion used for spray drying contains polyvinyl alcohol or a copolymer containing polyvinyl alcohol or a mixture of two or more such polymers, the proportion of these polymers in the total dispersion used for spray drying is about 5 to about 40, in particular about 10 to about 30,% by weight. -%. The proportion of the later capsule content in the dispersion used for spray drying is about 0.5 to about 40% by weight, for example about 1 to about 30% by weight. The lower limit of the proportion of the later capsule content in the dispersion used for spray drying can be, for example, 1.5, 2, 3, 4, 5, 6, 7, 8, 9 or 10% by weight. The upper limit for the proportion of the later capsule content in the dispersion used for spray drying is, for example, about 25% by weight, but in particular less than about 20% by weight, for example less than about 15% by weight.

The microcapsules according to the invention can be used in particular in the production of adhesives. For this purpose, the microcapsules according to the invention are surrounded with a matrix of a compound or a mixture of two or more compounds which can harden with the capsule content to form a covalent bond. In the context of the present invention, the term “curing” refers to a chemical curing reaction which takes place with an increase in molecular weight or crosslinking or both.

The present invention therefore also relates to an adhesive comprising at least one component A and one component B, wherein

Component A contains at least one microcapsule according to the invention according to one of claims 1 to 5 and

Component B contains at least one compound with at least two functional groups Y or at least one compound with at least two functional groups Y and at least one compound with at least two functional groups X and wherein the functional groups Y can react with the functional groups X to form a covalent bond.

In the context of the present invention, component A of the adhesive according to the invention can have, in addition to the microcapsules according to the invention, another component or two or more further components. In the context of the present invention, further constituents are also constituents which consist exclusively of the compounds contained in the microcapsules, but which have a different morphology. A different type of morphology can consist, for example, in that the constituent referred to as the capsule content is not enclosed by the capsule shell but only adheres to the capsule shell at one or more points and thus forms an aggregate of the capsule contents and capsule shell material. Likewise, the term “different morphology” relates to aggregates which consist exclusively of the compounds contained in the microcapsules, but in which several of the constituents forming the capsule content adhere to a structure made of capsule shell material, for example spherical.

Component B of the adhesive according to the invention contains, for example, at least one compound with at least two functional groups Y. A compound contained in component B of the adhesive according to the invention can carry two or more identical functional groups Y. However, it is also possible for a compound contained in component of each adhesive according to the invention to carry two or more different functional groups Y.

In the context of a further embodiment of the invention, component B of the adhesive according to the invention contains at least one compound with min. at least two functional groups Y and at least one compound with at least two functional groups X.

Suitable functional groups Y are basically all functional groups which can react with the functional groups X to form a covalent bond. In particular, the functional group Y represents a functional group selected from the group consisting of isocyanates, epoxides, carboxylic acids, carboxylic esters, carboxylic acid chlorides or carboxylic acid anhydrides.

In a preferred embodiment of the present invention, the functional group Y represents an epoxy group or an isocyanate group.

In a further preferred embodiment, component B contains at least one epoxy resin, as is the case, for example, by reacting polyhydric phenols such as bisphenol-A, bisphenol-F, catechol or resorcinol or polyhydric alcohols such as glycerol, trimethylolpropane, pentaerythritol, sugars such as glucose , Fructose, mannose, galactose, dextrose, sorbitol or mannitol and their reaction products with ethylene oxide or propylene oxide or a mixture thereof, or of hydroxycarboxylic acids such as p-hydroxybenzoic acid or 2-hydroxynaphthenic acid with epichlorohydrin. Also suitable are, for example, polyglycidyl esters as can be obtained by reacting polycarboxylic acids such as phthalic acid, isophthalic acid or terephthalic acid with epichlorohydrin. Also suitable as epoxy resins are the reaction products of amines such as 4,4'-diaminodiphenylmethane, m-aminophenol and the like, for example the reaction products of the amines already mentioned above as capsule content with epichlorohydrin. Also suitable are polymeric epoxy resins, such as those obtained by reacting appropriate prepolymers, for example prepolymers carrying OH groups or NH groups. are available with epichlorohydrin. Such polymeric epoxy resins can have, for example, two or more epoxy groups. The epoxy groups can, for example, be arranged at the chain end of the polymers, but they can also be arranged within the polymer chain.

Suitable prepolymers are, for example, polymeric polyol components such as the reaction products of low molecular weight polyfunctional alcohols with alkyl oxides, so-called polyethers. The alkylene oxides preferably have 2 to 4 carbon atoms. For example, the reaction products of ethylene glycol, propylene glycol, the isomeric butanediols or hexanediols with ethylene oxide, propylene oxide or butylene oxide, or mixtures of two or more thereof, are suitable. Furthermore, the reaction products of polyfunctional alcohols, such as glycerol, trimethylolethane or trimethylolpropane, pentaerythritol or sugar alcohols, or mixtures of two or more thereof, with the alkylene oxides mentioned to form polyether polyols are also suitable. Particularly suitable are polyether polyols with a molecular weight of about 100 to about 10,000, preferably from about 200 to about 5,000. Within the scope of the present invention, polypropylene glycol with a molecular weight of approximately 300 to approximately 2500 is very particularly preferred. Also suitable as a polyol component for the production of the epoxides are polyether polyols, such as those obtained from the polymerization of tetrahydrofuran.

The polyethers are reacted in a manner known to those skilled in the art by reacting the starting compound with a reactive hydrogen atom with alkylene oxides, for example ethylene oxide, propylene oxide, butylene oxide, styrene oxide, tetrahydrofuran or epichlorohydrin or mixtures of two or more thereof.

Suitable starting compounds are, for example, water, ethylene glycol, propylene glycol 1,2 or 1,3, butylene glycol 1,4 or 1,3 hexanediol 1,6, octanediol 1,8, neopentyl glycol, 1,4-hydroxymethylcyclohexane, 2-methyl-l, 3-propanediol, glycerol, trimethylolpropane, hexanetriol-1,2,6, butanetriol-1,2,4 trimethylolethane, pentaerythritol, mannitol, sorbitol, methylglycosides , Sugar, phenol, isononylphenol, resorcinol, hydroquinone, 1,2,2- or l, l, 2-tris (hydroxyphenyl) -ethane, ammonia, methylamine, ethylenediamine, tetra- or hexamethyleneamine, triethanolamin , Aniline, phenylenediamine, 2,4- and 2,6-diaminotoluene and polyphenylpolymethylene polyamines, as can be obtained by aniline-formaldehyde condensation, or mixtures of two or more thereof.

Also suitable for use as a polyol component in the production of corresponding epoxides are polyethers which have been modified by vinyl polymers. Such products can be obtained, for example, by polymerizing styrene or acrylonitrile, or a mixture thereof, in the presence of polyethers.

Also suitable as a polyol component for the production of corresponding epoxides are polyester polyols with a molecular weight of approximately 200 to approximately 10,000. For example, polyester polyols can be used which are formed by reacting low molecular weight alcohols, in particular ethylene glycol, diethylene glycol, neopentyl glycol, hexanediol, butanediol, propylene glycol, glycerol or trimethylolpropane with caprolactone. Also suitable as polyfunctional alcohols for the production of polyester polyols are 1,4-hydroxymethylcyclohexane, 2-methyl-l, 3-propanediol, butanetriol-1,2,4, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, dibutylene glycol and polybutylene glycol.

Other suitable polyester polyols can be produced by polycondensation. So difunctional and / or trifunctional alcohols with a deficit of dicarboxylic acids and / or tricarboxylic acids, or their reactive derivatives Polyester polyols are condensed. Suitable dicarboxylic acids are, for example, succinic acid and its higher homologues with up to 16 carbon atoms, furthermore unsaturated dicarboxylic acids such as maleic acid or fumaric acid and aromatic dicarboxylic acids, in particular the isomeric phthalic acids such as phthalic acid, isophthalic acid or terephthalic acid. Citric acid or trimellitic acid, for example, are suitable as tricarboxylic acids. Within the scope of the invention, polyester polyols from at least one of the dicarboxylic acids and glycerol mentioned, which have a residual OH group content, are particularly suitable. Particularly suitable alcohols are hexanediol, ethylene glycol, diethylene glycol or neopentyl glycol or mixtures of two or more thereof. Particularly suitable acids are isophthalic acid or adipic acid or a mixture thereof.

In the context of the present invention, for example, polyols used as polyol components for the production of the epoxides are dipropylene glycol and polyester polyols, preferably polyester polyols obtainable by polycondensation of hexanediol, ethylene glycol, diethylene glycol or neopentyl glycol or mixtures of two or more thereof and isophthalic acid or adipic acid, or mixtures thereof.

High molecular weight polyester polyols include, for example, the reaction products of polyfunctional, preferably difunctional alcohols (optionally together with small amounts of frifunctional alcohols) and polyfunctional, preferably difunctional carboxylic acids. Instead of free polycarboxylic acids, the corresponding polycarbonic acid anhydrides or corresponding polycarboxylic acid esters with alcohols with preferably 1 to 3 carbon atoms can also be used (if possible). The polycarboxylic acids can be aliphatic, cycloaliphatic, aromatic or heterocyclic, or both. They can optionally be substituted, for example by alkyl groups, alkenyl groups, ether groups or halogens. Examples of polycarboxylic acids are succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, Phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, endomethylene tetrahydrophthalic anhydride, glutaric anhydride or maleic acid, dimeric acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid. If necessary, minor amounts of monofunctional fatty acids can be present in the reaction mixture.

The polyesters can optionally have a small proportion of carboxyl end groups. Polyesters obtainable from lactones, for example ε-caprolactone or hydroxycarboxylic acids, for example ω-hydroxycaproic acid, can also be used.

Polyacetals are also suitable as the polyol component. Polyacetals are understood to mean compounds such as are obtainable from glycols, for example diethylene glycol or hexanediol, or a mixture thereof with formaldehyde. Polyacetals which can be used in the context of the invention can likewise be obtained by the polymerization of cyclic acetals.

Polycarbonates are also suitable as the polyol component. Polycarbonates can be obtained, for example, by the reaction of diols, such as propylene glycol, 1,4-butanediol or 1,6-hexanediol, diethylene glycol, triethylene glycol or tetraethylene glycol, or mixtures of two or more thereof with diaryl carbonates, for example diphenyl carbonate, or phosgene become.

Particularly suitable epoxides are, for example, epoxy DER-331 (manufacturer: Dow Chemicals) or the epoxides of the Epikote series, for example Epikote 828 (manufacturer: Shell AG). The reaction product of bisphenol-A and epichlorohydrin is particularly suitable in the context of the present invention. In the context of a further preferred embodiment of the present invention, component B contains one, two or more compounds which carry isocyanate groups as functional group Y. Such a compound bearing isocyanate groups can, for example, be of low molecular weight, ie, for example, have a molecular weight of less than about 250. However, it is also possible that the isocyanate group-bearing compound has a molecular weight higher than 250. In this case, polyurethane prepolymers, for example, can be used as compounds bearing isocyanate groups.

Compounds which carry isocyanate groups are, for example, compounds such as ethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), cyclobutane-l, 3-diisocyanate, cyclohexane-1,3- and -1,4-diisocyanate and mixtures two or more of them, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 2,4- and 2,6-hexahydrotoluenediisocyanate, tetramethylxylylene diisocyanate (TMXDI), 1,3- and 1,4 Phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate, diphenyl methane-2,4'-diisocyanate, diphenyl methane-2,2'-diisocyanate or diphenyl methane-4,4'-diisocyanate or mixtures of two or more of the above diisocyanates.

Also suitable as isocyanates for the purposes of the present invention are trivalent or higher-valent isocyanates, such as are obtainable, for example, by oligomerization of diisocyanates. Examples of such trivalent and higher polyisocyanates are the triisocyanurates from HDI or IPDI or their mixtures or their mixed triisocyanurates.

Also suitable are polyurethane prepolymers, such as those obtained by the reaction of polyfunctional isocyanates with a low molecular weight or polymeric polyol component are available. Examples of suitable polyfunctional isocyanates are the isocyanates described above.

A large number of polyols can be used as the low molecular weight polyol component. For example, these are aliphatic alcohols with 2 to 4 OH groups per molecule. The OH groups can be either primary or secondary. Suitable aliphatic alcohols include, for example, ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 7, 1,8-octanediol and their higher homologs or isomers , as they result for the person skilled in the art from a stepwise extension of the hydrocarbon chain by one CH2 group in each case or by introducing branches into the carbon chain. Highly functional alcohols such as, for example, glycerol, trimethylolpropane, pentaerythritol and oligomeric ethers of the substances mentioned with themselves or in a mixture of two or more of the ethers mentioned are also suitable.

Suitable polymeric polyol components are the polymeric polyol components already described above as being suitable for producing the epoxides.

Polyurethane prepolymers suitable for the purposes of the present invention preferably have a molecular weight of more than about 350, for example more than about 500 or more than about 1000. The upper limit of the molecular weight is generally limited by the application viscosity of a corresponding adhesive containing such a polyurethane prepolymer. If, for example, an adhesive of this kind is to be dispensed with, the molecular weight of such a polyurethane prepolymer is generally selected such that the adhesive has a suitable application viscosity. In this case, corresponding polyurethane prepolymers should have a molecular Have a specific weight that is, for example, less than about 50,000, in particular less than about 10,000. However, if the adhesive according to the invention can contain solvents, then polyurethane prepolymers with corresponding higher molecular weights can be used.

In principle, all solvents commonly used in polyurethane chemistry can be used as solvents, in particular esters, ketones, halogenated hydrocarbons, alkanes, alkenes and aromatic hydrocarbons. Examples of such solvents are methylene chloride, trichlorethylene, toluene, xylene, butyl acetate, amyl acetate, isobutyl acetate, methyl isobutyl ketone, methoxybutyl acetate, cyclohexane, cyclohexanone, dichlorobenzene, diethyl ketone, di-isobutyl ketone, dioxane, ethyl ethyl acetate, ethylene glycol ethyl acetate, ethylene glycol ethyl acetate, ethylene glycol ethyl acetate, ethylene glycol ethyl acetate, ethylene glycol ethyl acetate, ethylene glycol ethyl acetate, ethyl acetate, ethyl acetate, ethyl acetate, ethyl acetate, -Ethylhexylacetat, glycol diacetate, heptane, hexane, isobutyl acetate, iso-octane, isopropyl acetate, methyl ethyl ketone, tetrahydrofuran or tetrachlorethylene or mixtures of two or more of the solvents mentioned.

If, in addition to the compounds with functional groups Y described above, component B also has compounds with functional groups X, all compounds with functional groups X already described above are suitable for this.

In the adhesive according to the invention, the equivalent ratio of reactive functional groups X in component A to functional groups Y in component B or the ratio of functional groups X to functional groups Y in component B or, if components A and B have at least one compound with functional groups X. , the ratio of functional groups X in component A and B to functional groups Y in component B about 1: 100 to about 1: 1. In the context of the present invention, the term “equivalent ratio” means the ratio of functional understood new groups X to functional groups Y.

Another object of the present invention is a method for producing an adhesive according to the invention, in which a component A and a component B, wherein

Component A contains at least one microcapsule according to one of claims 1 to 5 and

Component B contains at least one compound with at least two functional groups Y or at least one compound with at least two functional groups Y and at least one compound with at least two functional groups X and wherein the functional groups Y can react with the functional groups X to form a covalent bond .

be mixed.

Another object of the invention is the use of a microcapsule according to the invention or a microcapsule produced by a method according to the invention for the production of adhesives.

The invention is explained in more detail below by examples

Examples:

example 1 Production of cellulose ether-encapsulated 4-aminodiphenylamine

1% by weight of 4-aminodiphenylamine with a particle size of less than 10 μm was dispersed in 180 ml of a 2% strength solution of methylhydroxypropyl cellulose (culminal MHPC 400). The dispersion was then treated in an ultrasonic bath at about 23 ° C. for 3 minutes. The dispersion thus obtained was then spray-dried in a laboratory spray drying apparatus (Büchi company, Büchi model 190). Here, a nozzle cap with a diameter of 0.7 mm was used. The conditions prevailing during spray drying are shown in Table 1 below.

Table 1: Processing conditions for spray drying the MHPC dispersion

Example 2

Production of styrene / polyvinyl alcohol-encapsulated 4-aminodiphenylamine

To produce a styrene / polyvinyl alcohol dispersion, 560 g of demineralized water were preheated to 75 ° C. in a round-bottom flask equipped with a stirrer, cooler and heating. 100 g of polyvinyl alcohol (Polyviol V 03/140) were dissolved in this. Then 10 g of styrene were added to the solution and emulsified for about 2 minutes. After adding 40 g of a 2.5% strength potassium persulfate solution, 90 g of styrene were added dropwise to the solution over a further 30 minutes. The mixture was then stirred for a further 30 minutes. After the reaction had ended, the emulsion was cooled to room temperature. A styrene / polyvinyl alcohol dispersion with a solids content of 25.2% was formed. 6% by weight of 4-aminodiphenylamine were dispersed in this dispersion and then treated in an ultrasound bath for 3 minutes. The dispersion thus obtained was then processed in the spray drying apparatus described above. The conditions prevailing during processing can be found in Table 2 below.

Table 2: Processing conditions for spray drying the styrene / polyvinyl alcohol

dispersion

Example 3:

Manufacture of adhesives

To produce the adhesives according to the invention, the components listed in Table 3 below were stirred together. Table 3: Mixing ratios of adhesive components A and B

Epoxy A: reaction product of bisphenol-A with 2 mol epichlorohydrin

The compounds listed in Table 3 were then stored in a wide-mouth screw cap bottle. The result of the storage is shown in Table 4 below

Table 4: Storage characteristics

Claims

claims

1. Microcapsule, consisting of a capsule shell and a capsule content, the capsule shell at least one water-soluble or water-dispersible polymer with a molecular weight of more than 3000 and the capsule content at least one compound with at least two functional groups reactive towards isocyanate groups or epoxy groups or carboxyl groups X or a catalyst which accelerates the reaction between isocyanate groups or epoxy groups or carboxyl groups and a compound having at least two functional groups X which are reactive toward isocyanate groups or epoxy groups or carboxyl groups, or both.

Microcapsule according to Claim 1, characterized in that the capsule shell contains at least 30% by weight of a water-soluble polymer.

3. Microcapsule according to claim 1 or 2, characterized in that the capsule shell cellulose or a cellulose derivative, polyvinyl alcohol or a partially or completely saponified block copolymer of vinyl acetate and at least one further polymerizable monomer, or a

Mixture of two or more of them contains.

4. Microcapsule according to one of claims 1 to 3, characterized in that the capsule shell has a wall thickness of at least 100 nm.

5. Microcapsule according to one of claims 1 to 4, characterized in that the functional groups X independently of one another represent an amino group or an OH group.

6. adhesive, at least containing a component A and a component B, wherein

Component A contains at least one microcapsule according to one of claims 1 to 5 and - component B contains at least one compound with at least two functional groups Y or at least one compound with at least two functional groups Y and at least one compound with at least two functional groups X and

wherein the functional groups Y can react with the functional groups X to form a covalent bond.

7. Adhesive according to claim 6, characterized in that the functional groups Y independently of one another represent a functional group selected from the group consisting of isocyanates, epoxides, carboxylic acids, carboxylic esters, carboxylic acid chlorides or carboxylic acid anhydrides.

8. Adhesive according to claim 6 or 7, characterized in that the equivalent ratio of reactive functional groups X in component A to functional groups Y in component B or the ratio of functional groups X to functional groups Y in component B. or, if components A and B have at least one compound with functional groups X, the ratio of functional groups X in components A and B to functional groups Y in component B is about 1: 100 to about 1: 1.

9. A method for producing a microcapsule according to any one of claims 1 to 5, in which an aqueous solution or dispersion of at least one water-soluble or water-dispersible polymer having a molecular weight of more than 3000, wherein a compound having at least two functional isocyanate groups or epoxy groups or carboxyl groups reactive Groups X or a catalyst which accelerates the reaction between isocyanate groups or epoxy groups or carboxyl groups and functional groups X reactive to isocyanate groups or epoxy groups or carboxyl groups or a mixture of two or more of which is dispersed is subjected to spray drying, a microcapsule consisting of forms a capsule shell and a capsule content.

10. The method according to claim 9, characterized in that the weight ratio of water-soluble or water-dispersible polymer to the functional groups X-carrying compounds or to the catalyst or to the mixture of two or more thereof in the aqueous solution or dispersion about 1:10 to about 20 : 1 is.

11. The method according to any one of claims 9 or 10, characterized in that the weight ratio of water-soluble or water-dispersible polymer to the functional group X-carrying compounds to the catalyst or to the mixture of two or more thereof in the aqueous solution or dispersion 2: 1 to 7 : 1 is.

12. The method according to claim 9 to 11, characterized in that the aqueous solution or dispersion contains 0.1 to 40 wt .-% of the water-soluble or water-dispersible polymer.

13. A method for producing an adhesive according to any one of claims 6 to 8, characterized in that a component A and a component B, wherein

- Component A contains at least one microcapsule according to one of claims 1 to 5 and

be mixed.

14. Use of a microcapsule according to one of claims 1 to 5 or produced according to one of claims 9 to 12 for the production of adhesives.