DE102004024436A1 - Self-adhesive one-component sealing material based on a polyurethane dispersion used e.g. for sealing polyolefin or polyester film onto wood or fibre cement board - Google Patents

Abstract

One-component sealing material (I) based on a polyurethane dispersion, which is self-adhesive in the dry state. An independent claim is also included for composite material comprising wood and/or fibre cement board, sealing material (I) and a polyolefin and/or polyester film.

Description

The The present invention relates to a one-component self-adhesive Sealant, wherein the sealant in the wet state substantially free from volatile organic compounds and in the dry state is self-adhesive. Furthermore, the invention relates to the preparation and use this sealant and composites made with this sealant.

The Methods of connection technology are generally used in gluing and Divided densities. For Adhesives and sealants are usually used the same raw materials. The specific properties be over the mixing ratios the raw materials set. So it is with adhesives according to DIN 16920 non-metallic, the parts to be joined by surface adhesion and internal strength (adhesion and cohesion) can connect and in the case of sealants according to DIN 52460 plastic or elastic permanent masses for sealing leaks, so-called joints.

The Most known sealants are no longer in the dry state sticky. This property is desirable because it causes sticking is avoided by dirt. Nevertheless, there is a need for sealants, which are self-adhesive even when dry. So describes the patent application DE-A-100 00 940 a self-adhesive in the dry state Sealant based on vinyl polymers.

task The present invention was the provision of sealing compounds, which are self-adhesive in the dry state.

In addition, should the above-mentioned sealants in the wet state free from volatile be organic compounds in the dry state an improved peel adhesion show and achieve an effective seal.

The Task was by a one-component sealant based on Polyurethane dispersions dissolved.

• i. 10 bis 98 Gew.-%, vorzugsweise 25 bis 60 Gew.-%, besonders bevorzugt 35 bis 50 Gew.-%, wenigstens einer Polyurethandispersion, wobei die Polyurethandispersion beispielsweise einen Feststoffanteil von 30 bis 70 Gew.-%, vorzugsweise 35 bis 50 Gew.-%, aufweist,
• ii. 0 bis 35 Gew.-%, vorzugsweise 1 bis 25 Gew.-%, besonders bevorzugt 5 bis 20 Gew.-%, eines oder mehrerer Polyacrylat-Weichharze als organischen Füllstoff,
• iii. 0 bis 50 Gew.-%, vorzugsweise 10 bis 45 Gew.-%, besonders bevorzugt 15 bis 40 Gew.-%, eines oder mehrerer zusätzlicher organischer Füllstoffe,
• iv. 0 bis 60 Gew.-%, vorzugsweise 10 bis 40 Gew.-%, besonders bevorzugt 20 bis 30 Gew.-%, eines oder mehrerer anorganischer Füllstoffe,
• v. 0 bis 10 Gew.-%, vorzugsweise 1 bis 5 Gew.-%, besonders bevorzugt 2 bis 3 Gew.-%, eines oder mehrerer zusätzlicher anorganischer Füllstoffe als Thixotropierungsmittel,
• vi. 0 bis 5 Gew.-%, vorzugsweise 0,01 bis 2,5 Gew.-%, besonders bevorzugt 0,1 bis 1 Gew.-%, eines oder mehrerer Verdicker,
• vii. 0 bis 5 Gew.-%, vorzugsweise 0,1 bis 2,5 Gew.-%, besonders bevorzugt 0 bis 1 Gew.-%, eines oder mehrerer Pigmente und
• viii. 0 bis 20 Gew.-%, vorzugsweise 0 bis 10 Gew.-%, besonders bevorzugt 0 bis 5 Gew.-% weitere Hilfsstoffe,

wobei das Verhältnis von i zu (ii+iii+iv) vorzugsweise von 0,3 bis 2, besonders bevorzugt von 0,6 bis 1, beträgt.The sealant according to the invention contains in the wet state

• i. 10 to 98 wt .-%, preferably 25 to 60 wt .-%, particularly preferably 35 to 50 wt .-%, of at least one polyurethane dispersion, wherein the polyurethane dispersion, for example, a solids content of 30 to 70 wt .-%, preferably 35 to 50 Wt .-%,
• ii. 0 to 35 wt .-%, preferably 1 to 25 wt .-%, particularly preferably 5 to 20 wt .-%, of one or more polyacrylate soft resins as organic filler,
• iii. 0 to 50% by weight, preferably 10 to 45% by weight, particularly preferably 15 to 40% by weight, of one or more additional organic fillers,
• iv. 0 to 60 wt .-%, preferably 10 to 40 wt .-%, particularly preferably 20 to 30 wt .-%, of one or more inorganic fillers,
• v. 0 to 10 wt .-%, preferably 1 to 5 wt .-%, particularly preferably 2 to 3 wt .-%, of one or more additional inorganic fillers as thixotropic agent,
• vi. 0 to 5 wt .-%, preferably 0.01 to 2.5 wt .-%, particularly preferably 0.1 to 1 wt .-%, of one or more thickeners,
• vii. 0 to 5 wt .-%, preferably 0.1 to 2.5 wt .-%, particularly preferably 0 to 1 wt .-%, of one or more pigments and
• viii. 0 to 20 wt .-%, preferably 0 to 10 wt .-%, particularly preferably 0 to 5 wt .-% further auxiliaries,

wherein the ratio of i to (ii + iii + iv) is preferably from 0.3 to 2, more preferably from 0.6 to 1.

The Polyurethane dispersion (i) is preferably aqueous and contains at least a polyurethane. In addition, you can further polymeric binders may be present.

The polyurethanes are predominantly preferably polyisocyanates, in particular diisocyanate on the one hand and, on the other hand, as reactants, polyester diols, polyether diols or mixtures thereof.

Preferably the polyurethane is at least 40 wt .-%, particularly preferred at least 60% by weight, and most preferably at least 80 wt .-% of diisocyanates, polyether diols and / or polyester diols built up.

Preferably the polyurethane has a softening point or melting point in the Range from -50 to 150 ° C, especially preferably from 0 to 100 ° C, and most preferably from 10 to 90 ° C.

Especially Preferably, the polyurethane has a melting point in the above Temperature range.

Prefers contains the polyurethane in addition to polyester diols in an amount of more than 10 wt .-%, based on the polyurethane.

• a) Diisocyanaten,
• b) Diolen, von denen b₁) 10 bis 100 mol-%, bezogen auf die Gesamtmenge der Diole (b), ein Molekulargewicht von 500 bis 5000 g/mol aufweisen, b₂) 0 bis 90 mol-%, bezogen auf die Gesamtmenge der Diole (b), ein Molekulargewicht von 60 bis 500 g/mol aufweisen,
• c) von den Monomeren (a) und (b) verschiedene Monomere mit wenigstens einer Isocyanatgruppe oder wenigstens einer gegenüber Isocyanatgruppen reaktiven Gruppe, die darüber hinaus wenigstens eine hydrophile Gruppe oder eine potentiell hydrophile Gruppe tragen, wodurch die Wasserdispergierbarkeit der Polyurethane bewirkt wird,
• d) gegebenenfalls weiteren von den Monomeren (a) bis (c) verschiedenen mehrwertigen Verbindungen mit reaktiven Gruppen, bei denen es sich um alkoholische Hydroxylgruppen, primäre oder sekundäre Aminogruppen oder Isocyanatgruppen handelt und
• e) gegebenenfalls von den Monomeren (a) bis (d) verschiedenen einwertigen Verbindungen mit einer reaktiven Gruppe, bei der es sich um eine alkoholische Hydroxylgruppe, eine primäre oder sekundäre Aminogruppe oder eine Isocyanatgruppe handelt.

Overall, the polyurethane is preferably composed of:

• a) diisocyanates,
• b) diols, of which b ₁ ) have 10 to 100 mol%, based on the total amount of diols (b), of a molecular weight of 500 to 5000 g / mol, b ₂ ) 0 to 90 mol%, based on the Total amount of diols (b), have a molecular weight of 60 to 500 g / mol,
• c) monomers other than monomers (a) and (b) having at least one isocyanate group or at least one isocyanate group-reactive group further having at least one hydrophilic group or a potentially hydrophilic group, thereby causing the water dispersibility of the polyurethanes;
• d) optionally other polyfunctional compounds other than the monomers (a) to (c), having reactive groups which are alcoholic hydroxyl groups, primary or secondary amino groups or isocyanate groups, and
• e) optionally monovalent compounds other than the monomers (a) to (d), having a reactive group which is an alcoholic hydroxyl group, a primary or secondary amino group or an isocyanate group.

Particular mention may be made as monomers (a) diisocyanates X (NCO) ₂ , wherein X is an aliphatic hydrocarbon radical having 4 to 15 carbon atoms, a cycloaliphatic or aromatic hydrocarbon radical having 6 to 15 carbon atoms or an araliphatic hydrocarbon radical having 7 to 15 carbon atoms. Examples of such diisocyanates are tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 1,4-diisocyanatocyclohexane, 1-isocyanato-3,5,5-trimethyl-5-isocyanatomethylcyclohexane (IPDI), 2,2-bis (4-isocyanatocyclohexyl) -propane, trimethylhexane diisocyanate , 1,4-diisocyanatobenzene, 2,4-diisocyanatotoluene, 2,6-diisocyanatotoluene, 4,4'-diisocyanato-diphenylmethane, 2,4'-diisocyanatodiphenylmethane, p-xylylene diisocyanate, tetramethylxylylene diisocyanate (TMXDI), the isomers of bis ( 4-isocyanatocyclohexyl) methane (HMDI) such as the trans / trans, the cis / cis and the cis / trans isomers and mixtures consisting of these compounds.

such Diisocyanates are commercially available.

When Mixtures of these isocyanates are especially the mixtures of the respective Structured isomers of diisocyanatotoluene and diisocyanato-diphenylmethane significant.

Especially is the mixture of 80 mol% 2,4-diisocyanatotoluene and 20 mol% 2,6-diisocyanatotoluene suitable. Furthermore, the mixtures of aromatic isocyanates such as 2,4-diisocyanatotoluene and / or 2,6-diisocyanatotoluene with aliphatic or cycloaliphatic isocyanates such as hexamethylene diisocyanate or IPDI particularly advantageous, wherein the preferred mixing ratio of the aliphatic to aromatic isocyanates 4: 1 to 1: 4.

To the Construction of the polyurethanes can be considered as compounds except the The above also use isocyanates, in addition to the free isocyanate groups other capped isocyanate groups, for example uretdione groups wear.

With regard to good film formation and elasticity, suitable diols (b) are primarily relatively high molecular weight diols (b ₁ ) which have a molecular weight of about 500 to 5,000, preferably about 1,000 to 3,000 g / mol. This is the number average molecular weight M _n . M _n is determined by determining the number of end groups (OH number).

The diols (b ₁ ) may be polyester polyols, which are known, for example, from Ullmanns Encyklopadie der technischen Chemie, 4th edition, volume 19, pages 62 to 65. Preference is given to using polyesterpolyols which are obtained by reacting dihydric alcohols with dibasic carboxylic acids. Instead of the free polycarboxylic acids, it is also possible to use the corresponding polycarboxylic acid anhydrides or corresponding polycarboxylic acid esters of lower alcohols or mixtures thereof to prepare the polyesterpolyols. The polycarboxylic acids may be aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic and optionally substituted, for example by halogen atoms, and / or unsaturated. Examples of these are: suberic acid, azelaic acid, phthalic acid, isophthalic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, endomethylenetetrahydrophthalic anhydride, glutaric anhydride, maleic acid, maleic anhydride, fumaric acid, dimer fatty acids. Preference is given to dicarboxylic acids of the general formula HOOC- (CH ₂ ) _y -COOH, where y is a number from 1 to 20, preferably an even number from 2 to 20, for example succinic acid, adipic acid, sebacic acid and dodecanedicarboxylic acid.

Suitable polyhydric alcohols are, for example, ethylene glycol, propane-1,2-diol, propane-1,3-diol, butane-1,3-diol, butene-1,4-diol, butyne-1,4-diol, pentane-1 , 5-diol, neopentyl glycol, bis (hydroxymethyl) cyclohexanes such as 1,4-bis (hydroxymethyl) cyclohexane, 2-methylpropane-1,3-diol, methylpentanediols, furthermore diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol , Polypropylene glycol, dibutylene glycol and polybutylene glycols into consideration. Alcohols of the general formula HO- (CH ₂ ) _x -OH, where x is a number from 1 to 20, preferably an even number from 2 to 20, are preferred. Examples of these are ethylene glycol, butane-1,4-diol, hexane-1,6-diol, octane-1,8-diol and dodecane-1,12-diol. Further preferred is neopentyl glycol.

Further optionally also polycarbonate diols, as for example by reaction of phosgene with an excess of the as constituent components for the Polyesterpolyole called low molecular weight alcohols are obtained can, into consideration.

Optionally, it is also possible to use polyester-based lactone-based sols, which are homopolymers or copolymers of lactones, preferably hydroxyl-terminated addition products of lactones to suitable difunctional starter molecules. Suitable lactones are preferably those which are derived from compounds of the general formula HO- (CH ₂ ) _z -COOH, where z is a number from 1 to 20 and an H atom of a methylene unit is also denoted by a C ₁ - to C _4- alkyl radical may be substituted. Examples are c-caprolactone, β-propiolactone, γ-butyrolactone and / or methyl-ε-caprolactone and mixtures thereof. Suitable starter components are, for example, the low molecular weight dihydric alcohols mentioned above as a builder component for the polyesterpolyols. The corresponding polymers of ε-caprolactone are particularly preferred. Lower polyester diols or polyether diols can also be used as starters for the preparation of the lactone polymers. Instead of the polymers of lactones, it is also possible to use the corresponding, chemically equivalent polycondensates of the hydroxycarboxylic acids corresponding to the lactones.

Polyetherdiols are in particular by polymerization of ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide or epichlorohydrin with itself, for example in the presence of BF ₃ or by addition of these compounds, optionally in admixture or sequentially, to starting components with reactive hydrogen atoms, such as alcohols or amines, for example Water, ethylene glycol, propane-1,2-diol, propane-1,3-diol, 2,2-bis (4-hydroxyphenyl) -propane or aniline available. Particularly preferred are polypropylene oxide, polytetrahydrofuran having a molecular weight (M _n ) of 240 to 5000, and especially 500 to 4500.

Diols (b ₁ ) include only polyether diols which consist of less than 20% by weight of ethylene oxide. Polyether diols containing at least 20% by weight are hydrophilic polyether diols which belong to monomers (c).

Optionally, it is also possible to use polyhydroxyolefins, preferably those having 2 terminal hydroxyl groups, for example α, -ω-dihydroxypolybutadiene, α, -ω-dihydroxypolymethacrylic esters or α, -ω-dihydroxypolyacrylic esters as monomers (c ₁ ). Such compounds are known, for example, from EP-A-0 622 378. Further suitable polyols are polyacetals, polysiloxanes and alkyd resins.

Preferably, at least 95 mol% of the diols (b ₁ ) are polyether diols. Especially be As diols (b ₁ ) it is preferred to use exclusively polyether diols.

The hardness and the modulus of elasticity of the polyurethanes can be increased if, as diols (b), in addition to the diols (b ₁ ), low molecular weight diols (b ₂ ) having a molecular weight (M _n ) of about 60 to 500, preferably 62 to 200 g / mol, are used.

As diols (b ₂ ), especially the structural components of the mentioned for the production of polyester polyols short-chain alkanediols are used, wherein the unbranched diols having 2 to 12 carbon atoms and an even number of carbon atoms and pentane-1,5-diol and Neopentyl glycol are preferred.

Examples of suitable diols b ₂ ) are ethylene glycol, propane-1,2-diol, propane-1,3-diol, butane-1,3-diol, butene-1,4-diol, butyne-1,4-diol, pentane -1,5-diol, neopentyl glycol, bis (hydroxymethyl) cyclohexanes such as 1,4-bis (hydroxymethyl) cyclohexane, 2-methyl-propane-l, 3-diol, methylpentanediols, furthermore diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol , Dipropylene glycol, polypropylene glycol, dibutylene glycol and polybutylene glycols into consideration. Alcohols of the general formula HO- (CH ₂ ) _x -OH, where x is a number from 1 to 20, preferably an even number from 2 to 20, are preferred. Examples of these are ethylene glycol, butane-1,4-diol, hexane-1,6-diol, octane-1,8-diol and dodecane-1,12-diol. Further preferred is neopentyl glycol.

The proportion of the diols (b ₁ ), based on the total amount of the diols (b), is preferably 10 to 100 mol% and the proportion of the monomers (b ₂ ), based on the total amount of the diols (b), is 0 to 90 mol%. %. The ratio of the diols (b ₁ ) to the diols (b ₂ ) is particularly preferably 0.1: 1 to 5: 1, particularly preferably 0.2: 1 to 2: 1.

Around to achieve the water dispersibility of the polyurethanes containing the polyurethanes are different from components (a), (b) and (d) Monomers (c) containing at least one isocyanate group or at least one opposite Isocyanate groups reactive group and moreover at least one hydrophilic Carry a group or a group which can be converted into a hydrophilic group, as a building component. In the following text, the term "hydrophilic groups or potentially hydrophilic groups "with" (potentially) hydrophilic groups " (potentially) hydrophilic groups react significantly with isocyanates slower than the functional groups of the monomers used to build serve the polymer main chain.

Of the Proportion of components with (potentially) hydrophilic groups on the Total amount of components (a), (b), (c), (d) and (e) is generally such that the molar amount of the (potentially) hydrophilic groups, based on the amount by weight of all monomers (a) to (e), 30 to 1000, preferably 50 to 500 and particularly preferably 80 to 300 mmol / kg is.

at the (potentially) hydrophilic groups may be nonionic or preferably (ionic) hydrophilic groups.

When Nonionic hydrophilic groups are especially polyethylene glycol ethers preferably from 5 to 100, preferably from 10 to 80 ethylene oxide repeating units, into consideration. The content of polyethylene oxide units is generally 0 to 10, preferably 0 to 6 wt .-%, based on the amount by weight of all Monomers (a) to (e).

preferred Monomers having nonionic hydrophilic groups are polyethylene oxide diols with at least 20 wt .-% ethylene oxide, polyethylene oxide monools and the reaction products of a polyethylene glycol and a diisocyanate, the one terminal carry etherified polyethylene glycol. Such diisocyanates and processes for their preparation are in the patents US-3,905,929 and US-3,920,598.

Ionian hydrophilic groups are especially anionic groups such as the sulfonate, the carboxylate and phosphate groups in the form of their alkali metal or ammonium salts and cationic groups such as ammonium groups, in particular protonated tertiary Amino groups or quaternary Ammonium groups.

Potentially ionic hydrophilic groups are especially those that are characterized by simple neutralization, hydrolysis or quaternization reactions can be converted into the abovementioned ionic hydrophilic groups, for example, carboxylic acid groups or tertiary Amino groups.

(Potentially) ionic monomers (c) are described, for example, in Ullmanns Encyklopadie Technical Chemistry, 4th Edition, Volume 19, S.311-313 and for example in DE-A 1 495 745 in detail described.

As (potentially) cationic monomers (c), especially monomers having tertiary amino groups are of particular practical importance, for example: tris- (hydroxyalkyl) -amines, N, N'-bis (hydroxyalkyl) -alkylamines, N-hydroxyalkyl-dialkylamines, tris - (aminoalkyl) -amines, N, N'-bis (aminoalkyl) -alkylamines, N-aminoalkyl-dialkylamines, wherein the alkyl radicals and alkanediyl moieties of these tertiary amines independently of one another consist of 1 to 6 carbon atoms. Furthermore, tertiary nitrogen atoms containing polyether having preferably two terminal hydroxyl groups, such as, for example, by alkoxylation of two bonded to amine nitrogen hydrogen atoms containing amines, such as methylamine, aniline or N, N'-dimethylhydrazine, are accessible in per se conventional manner into consideration. Such polyethers generally have a molecular weight between 500 and 6000 g / mol (M _n ).

These tertiary amines are converted into the ammonium salts either with acids, preferably strong mineral acids such as phosphoric acid, sulfuric acid, hydrohalic acids or strong organic acids or by reaction with suitable quaternizing agents such as C ₁ - to C ₆ -alkyl halides or benzyl halides, for example bromides or chlorides.

in welcher R¹ und R² für eine C₁- bis C₄-Alkandiyl-(Einheit) und R³ für eine C₁- bis C₄-Alkyl-(Einheit) steht und vor allem Dimethylolpropionsäure (DMPA) bevorzugt.Suitable monomers with (potentially) anionic groups are usually aliphatic, cycloaliphatic, araliphatic or aromatic carboxylic acids and sulfonic acids which carry at least one alcoholic hydroxyl group or at least one primary or secondary amino group. Preference is given to dihydroxyalkylcarboxylic acids, especially having 3 to 10 carbon atoms, as also described in US Pat. No. 3,412,054. In particular, compounds of the general formula (c ₁ )

in which R ¹ and R ^{2 is} a C ₁ - to C ₄ -alkanediyl (unit) and R ^{3 is} a C ₁ - to C ₄ -alkyl- (unit) and, in particular, dimethylolpropionic acid (DMPA) is preferred.

Farther Suitable dihydroxysulfonic acids and dihydroxyphosphonic acids such as 2,3-dihydroxypropanephosphonic acid are suitable.

Otherwise suitable are dihydroxyl compounds having a molecular weight above 500 to 10,000 g / mol with at least 2 carboxylate groups, which are known from DE-A 3,911,827. They are obtainable by reacting dihydroxyl compounds with tetracarboxylic dianhydrides such as pyromellitic dianhydride or cyclopentanetetracarboxylic dianhydride in a molar ratio of 2: 1 to 1.05: 1 in a polyaddition reaction. As dihydroxy compounds, in particular the diols as chain extenders are listed (b ₂₎ and the diols (b ₁₎ is suitable.

When Monomers (c) with opposite Isocyanate-reactive amino groups come aminocarboxylic acids such as Lysine, β-alanine or the adducts of aliphatic compounds mentioned in DE-A 2 034 479 diprimary Diamines to α, β-unsaturated carboxylic or sulfonic acids into consideration.

• – R⁴ und R⁵ unabhängig voneinander für eine C₁- bis C₆-Alkandiyl-Einheit, bevorzugt Ethylen

und X für COOH oder SO₃H stehen.Such compounds obey, for example, the formula (c ₂ ) H ₂ NR ⁴ -NH-R ⁵ -X (c ₂ ) in the

• - R ⁴ and R ^{5 are} independently a C ₁ - to C ₆ alkanediyl moiety, preferably ethylene

and X is COOH or SO ₃ H.

Particularly preferred compounds of the formula (c ₂ ) are N- (2-aminoethyl) -2-aminoethanecarboxylic acid and N- (2-aminoethyl) -2-aminoethanesulfonic acid or the corresponding alkali metal salts, Na being particularly preferred as the counterion.

Farther particularly preferred are the adducts of the abovementioned aliphatic diprimary Diamines of 2-acrylamido-2-methylpropanesulfonic acid, as for example in DE-B 1 954 090 are described.

If monomers with potentially ionic groups are used, their conversion into the ionic form before, but preferably after the isocyanate polyaddition, since the ionic monomers are often difficult to dissolve in the reaction mixture. The sulfonate or carboxylate groups are particularly preferably in the form of their salts with an alkali ion or an ammonium ion as the counterion.

The Monomers (d) other than the monomers (a) to (c) and which are optionally also constituents of the polyurethane, generally serve for crosslinking or chain extension. It are generally more than dihydric non-phenolic alcohols, Amines with 2 or more primary and / or secondary Amino groups and compounds in addition to one or more alcoholic Hydroxyl groups one or more primary and / or secondary amino groups wear.

alcohols with a higher one Valence being 2, which is used to set a certain branching or degree of crosslinking, are for example trimethylolpropane, glycerol or sugar.

Further Monoalcohols come into consideration, in addition to the hydroxyl group a further towards isocyanates reactive group such as monoalcohols with one or more primary and / or secondary Amino groups, for example monoethanolamine.

polyamines with 2 or more primary and / or secondary Amino groups are used especially when the chain extension or crosslinking in the presence of water, since amines usually faster than alcohols or water with isocyanates react. That's common then required if watery Dispersions of crosslinked polyurethanes or polyurethanes with high molecular weight desired become. In such cases The procedure is to prepare prepolymers with isocyanate groups, these rapidly dispersed in water and then by addition of compounds with several isocyanates chain-extended or crosslinked reactive amino groups.

For this Suitable amines are generally polyfunctional amines of the molecular weight range from 32 to 500 g / mol, preferably from 60 to 300 g / mol, which at least two amino groups selected from the group of primary and secondary Amino groups, contained. Examples include diamines such as diaminoethane, Diaminopropane, diaminobutane, diaminohexane, piperazine, 2,5-dimethylpiperazine, Amino-3-aminomethyl-3,5,5-trimethylcyclohexane (Isophorone diamine, IPDA), 4,4'-diaminodicyclohexylmethane, 1,4-diaminocyclohexane, aminoethylethanolamine, hydrazine, hydrazine hydrate or triamines such as diethylenetriamine or 1,8-diamino-4-aminomethyloctane.

The Amines can also in blocked form, e.g. in the form of the corresponding ketimines (see, for example, CA-A 1 129 128), ketazines (see, for example U.S. 4,269,748) or amine salts (see, for example, U.S. 4,292,226) be used. Oxazolidines, as used for example in the US 4,192,937 represent capped polyamines, the for the preparation of the polyurethanes of the invention for chain extension the prepolymers can be used. When using such capped polyamines they are generally with the prepolymers mixed in the absence of water and then this mixture with the dispersion water or a part of the dispersion water, so that the corresponding polyamines are released hydrolytically.

Prefers For example, mixtures of di- and triamines are used, more preferred Mixtures of isophorone diamine (IPDA) and diethylenetriamine (DETA).

The Polyurethanes preferably contain 1 to 30, more preferably 4 to 25 mol%, based on the total amount of components (b) and (d) a polyamine having at least 2 isocyanate-reactive amino groups as monomers (d).

For the same Purpose also higher as monomers (d) be used as divalent isocyanates. Commercially available compounds are, for example, the isocyanurate or the biuret of hexamethylene diisocyanate.

Monomers (e), which are optionally used, are monoisocyanates, monoalcohols and monoprimers and -secondary amines. In general, their proportion is at most 10 mol%, based on the total molar amount of the monomers. These monofunctional compounds usually carry further functional groups such as olefinic groups or carbonyl groups and serve to introduce functional groups into the polyurethane, which enable the dispersion or the crosslinking or further polymer-analogous reaction of the polyurethane. For this come into consideration monomers such as isopropenyl-α, α-dime ethylbenzyl isocyanate (TMI) and esters of acrylic or methacrylic acid such as hydroxyethyl acrylate or hydroxyethyl methacrylate.

These Monomer combination is excellently supplemented as Component (c) by diaminosulfonic acid-alkali salts; most notably by the N- (2-aminoethyl) -2-aminoethanesulfonic acid or their corresponding alkali salts, with the Na salt being most suitable and a mixture of DETA / IPDA as component (d).

On The field of polyurethane chemistry is well known as the Molecular weight of the polyurethanes by choosing the proportions of each other reactive monomers and the arithmetic mean of the number of reactive functional groups per molecule can be adjusted.

• A Molmenge an Isocyanatgruppen un der d
• B der Summe aus der Molmenge der Hydroxylgruppen und der Molmenge der funktionellen Gruppen, die mit Isocyanaten in einer Additionsreaktion reagieren können

0,5 : 1 bis 2 : 1, bevorzugt 0,8 : 1 bis 1,5, besonders bevorzugt 0,9 : 1 bis 1,2 : 1 beträgt. Ganz besonders bevorzugt liegt das Verhältnis A : B möglichst nahe an 1 : 1.Normally, the components (a) to (e) and their respective molar amounts are chosen so that the ratio A: B with

• A molar amount of isocyanate groups and the d
• B is the sum of the molar amount of the hydroxyl groups and the molar amount of the functional groups which can react with isocyanates in an addition reaction

0.5: 1 to 2: 1, preferably 0.8: 1 to 1.5, more preferably 0.9: 1 to 1.2: 1. Most preferably, the ratio A: B is as close as possible to 1: 1.

The used monomers (a) to (e) usually carry on average 1.5 to 2.5, preferably 1.9 to 2.1, more preferably 2.0 isocyanate groups or functional groups that react with isocyanates in an addition reaction can react.

The Polyaddition of components (a) to (e) for the preparation of the polyurethane is preferably at reaction temperatures of up to 180 ° C, preferably up to 150 ° C under normal pressure or under autogenous pressure.

The Production of polyurethanes, or of aqueous polyurethane dispersions is known in the art.

Particularly preferred aqueous dispersions of polyether polyurethane elastomers, such as Luphen D ^® 259 U (BASF Aktiengesellschaft, Germany), respectively.

When further polymeric binder, optionally in admixture with Polyurethanes used come through radical polymerization of ethylenically unsaturated Compounds (monomers) available Polymers into consideration.

such Polymers are preferably at least 40 wt .-%, preferably at least 60% by weight, more preferably at least 80% by weight from so-called main monomers.

The main monomers are selected from C ₁ -C ₂₀ -alkyl (meth) acrylates, vinyl esters of carboxylic acids containing up to 20 carbon atoms, vinylaromatics having up to 20 carbon atoms, ethylenically unsaturated nitriles, vinyl halides, vinyl ethers of from 1 to 10 carbon atoms. Atoms containing alcohols, aliphatic hydrocarbons having 2 to 8 carbon atoms and one or two double bonds or mixtures of these monomers.

Examples include (meth) acrylic acid alkyl esters having a C ₁ -C ₁₀ alkyl radical, such as methyl methacrylate, methyl acrylate, n-butyl acrylate, ethyl acrylate and 2-ethylhexyl acrylate.

Especially also mixtures of (meth) acrylic acid alkyl esters are suitable.

Vinylester of carboxylic acids with 1 to 20 carbon atoms are, for example, vinyl laurate, stearate, Vinyl propionate, Versatic acid vinyl ester and vinyl acetate.

When vinylaromatic compounds include vinyltoluene, α- and p-methylstyrene, α-butylstyrene, 4-n-butylstyrene, 4-n-decylstyrene and preferably styrene. examples for Nitriles are acrylonitrile and methacrylonitrile.

The vinyl halides are chloro, fluoro or bromo substituted ethylenically unsaturated compounds gen, preferably vinyl chloride and vinylidene chloride.

When Vinyl ethers are mentioned e.g. Vinyl methyl ether or vinyl isobutyl ether. Vinyl ether is preferably from 1 to 4 C-containing alcohols.

When Hydrocarbons having 2 to 8 carbon atoms and one or two olefinic Double bonds are ethylene, propylene, butadiene, isoprene and chloroprene called.

Preferred main monomers are the C ₁ - to C ₁₀ -alkyl acrylates and -methacrylates, in particular C ₁ - to C ₈ -alkyl acrylates and -methacrylates and vinylaromatics, in particular styrene and mixtures thereof.

All particularly preferred are methyl acrylate, methyl methacrylate, ethyl acrylate, n-butyl acrylate, n-hexyl acrylate, octyl acrylate and 2-ethylhexyl acrylate, Styrene and mixtures of these monomers.

Next the main monomer, the polymer may contain other monomers, For example, monomers with carboxylic acid, sulfonic acid or Phosphonic. Preferred are carboxylic acid groups. Examples which may be mentioned are acrylic acid, methacrylic acid, itaconic acid, maleic acid or Fumaric acid.

Further monomers are, for example, hydroxyl-containing monomers, in particular C ₁ -C ₁₀ -hydroxyalkyl (meth) acrylates, (meth) acrylamide.

When more monomers are above it phenyloxyethyl glycol mono (meth) acrylate, glycidyl acrylate, Glycidyl methacrylate, amino (meth) acrylates such as 2-aminoethyl- (meth-) called acrylate.

When other monomers may also be mentioned as crosslinking monomers.

The polymer is particularly preferably at least 40% by weight, in particular at least 60% by weight and very particularly preferably at least 80% by weight, of C ₁ -C ₂₀ -alkyl, in particular C ₁ -C ₁₀ -alkyl (meth) acrylates.

The Preparation of the polymers takes place in a preferred embodiment by emulsion polymerization, it is therefore an emulsion polymer.

The However, production can also be carried out, for example, by solution polymerization and subsequent dispersion done in water.

Polyacrylate soft resins (ii) are, for example, synthetic resins based on polyacrylates with a polyacrylate content of at least 60% by weight, preferably at least 80% by weight, more preferably 100% by weight.

The Polyacrylate soft resins can by solvent polymerization to be obtained. As monomers for the Lösemittelpolymerisaton are acrylic acid, methacrylic acid, acrylate and methacrylic acid esters suitable, preferred are acrylic acid and n-butyl acrylate, particularly preferred is n-butyl acrylate. Of course you can too Mixtures of the above monomers are used, for example from acrylic acid and n-butyl acrylate.

The acid number of the polyacrylate soft resin, measured according to DIN 53213, is preferably below 200 mg KOH / g, more preferably below 100 mg KOH / g.

The Polyacrylate soft resin (ii) preferably has a K value of 1 to 40, in particular from 5 to 30, particularly preferably from 10 to 20, measured according to DIN ISO 1628-1. The K value is a measure of the molecular weight and the viscosity of the polyacrylate soft resin.

The Glass transition temperature (Tg) of the polyacrylate soft resin (ii) is preferably -60 to + 10 ° C, especially preferably -55 to 0 ° C, most preferably -55 to -10 ° C. The glass transition temperature can be after the usual Determine methods, for example according to ASTM 3418/82.

Particularly preferred polyacrylate soft resins (ii) are polyacrylates based on n-butyl acrylate, such as acResin ^® DS 3500 or Acronal 4F ^® (BASF Aktiengesellschaft, Germany).

additional organic fillers (iii) are, for example, resins based on hydrocarbons or rosin, Tallharz, gum rosin, terpenes, oligomers of vinylic monomers, oligomeric Urethanes or esters, polyester-based polymeric softening agents as well Resin dispersions. Further suitable organic fillers (iii) are impact modifiers, Plastic fibers or plastic powder of, for example, polyacrylate, Polystyrene, polyester, polyamide, polyurethane, polyvinyl chloride, Polyolefins, polyvinyl acetate, polyisoprene, polyisobutylene or Block polymers thereof. The polymeric plasticizers are according to DIN 55945 around liquid or solid indifferent organic substances with low vapor pressure. Due to their release and swelling power reduce the hardness of the vinyl polymer and change his adhesion.

Also suitable for use are organic filler particles that are not readily to the water-soluble or water-dispersible polymers. These include in particular finely ground plastic flours, as in the recycling of plastics may be incurred. In particular, this includes Plastic flours, such as those from fine grinding of highly cross-linked elastomeric or thermosetting polymers are available. An example of this is rubber powder, as it arises, for example, by fine grinding of car tires. Plastic fibers, impact modifiers, Cellulose fibers, glass fibers (for example wollastonite brands).

Particularly preferred additional organic fillers (iii) are for example Aquatac ^® 6085 B 1 (Arizona Chemical, SE) and Bremasin ^® 1205 (Robert Kramer works paint resin, DE).

Suitable inorganic fillers (iv) are, for example, filler particles of andalusite, silimanite, kyanite, mullite, pyrophylite, omogolite or allophane. Also suitable are compounds based on sodium aluminates, silicates, such as, for example, aluminum silicates, calcium silicates or silicic acids (Aerosil) as thixotropic agents (v). Also suitable are minerals such as silica, calcium sulfate (gypsum), which does not originate from flue gas desulphurisation systems in the form of anhydrite, hemihydrate or dihydrate, quartz powder, silica gel, precipitated or natural barium sulfate, titanium dioxide, zeolites, leucite, potassium feldspar, biotite, the group of , Cyclo, ino, phyllo and tectosilicates, the group of sparingly soluble sulfates, such as gypsum, anhydrite or barite, and calcium minerals, such as calcite or chalk (CaCO ₃ ).

The mentioned inorganic materials can individually but also in a mixture be used. Other suitable materials are precipitated or natural Kaolin, talc, magnesium or aluminum hydroxide (for adjustment the fire class), zinc oxide and zirconium salts. By adding of light fillers - ceramic Hollow microspheres, hollow glass spheres, foam glass spheres or other Lightweight fillers, as produced, for example, by Omega-Minerals, parameters such as dimensional stability and density can be influenced.

A particularly preferred inorganic filler (iv) is for example silica sand mm with a particle size distribution of 0.001 to 0.5, most preferably 0.08 to 0.4 mm, and a particularly preferred thixotropic agent (v) is, for example, Aerosil ^® 200 (Degussa, DE).

at the thickening agents (vi) are usually high molecular weight Substances that either absorb water and thereby swell or form intermolecular lattice structures. The organic thickener finally go in a viscous real or colloidal solution over.

The organic thickener contains an aqueous system of a copolymer based on at least acrylic acid and acrylamide, preferably emulsified in an oil fraction, in particular in a petroleum fraction. The solids content of the system is 20 to 40, in particular 24 to 28% in accordance with DIN 53189 or ISO 1625. Especially preferably used is Collacral ^® C (BASF Aktiengesellschaft, Germany). The thickening effect of Collacral ^® C is achieved above all in the alkaline range, at a pH of 7 to 10.

But can also be used other thickeners based on acrylic acid and acrylamide (e.g. Collacral ^® HP) carboxlygruppenhaltige acrylate copolymers such as Latekoll ^® D, PU thickener (e.g. Collacral ^® PU 75), celluloses and their derivatives, and natural thickeners such as bentonites , Alginates or starch.

Low-emission to manufacture products that are often required in indoor applications, including powdered thickener, for example, (Collacral® ^® DS 6254, for example) are used based on acrylate.

The Thickeners (vi) are used in amounts of from 0 to 5% by weight, preferably 0.1 used to 1 wt .-%.

A particularly preferred thickener (vi), for example Collacral ^® C (BASF Aktiengesellschaft, Germany).

The pigments (vii) serve to color the sealant. Preference is given to organic pigments and iron oxides. Examples are the Luconyl ^® grades from BASF Aktiengesellschaft. The pigments are used in amounts of 0 to 5 wt .-%, preferably 0 to 1 wt .-%.

An especially preferred pigment (vii) is, for example Luconylblau ^® 6900 (BASF Aktiengesellschaft, Germany).

In summary it is in the one-component sealant substantially around a watery Polyurethane dispersion. Other excipients (viii) can be found in easy way of aqueous Dispersion can be added.

The further auxiliaries (viii) include, for example, preservatives for preventing fungal and bacterial attack, solvents for influencing the open time and the mechanical properties, for example butylglycol, dispersing aids for improving the wetting behavior, for example Pigment Distributor NL (BASF Aktiengesellschaft, DE), emulsifiers ( Emulphor ^® OPS 25, Lutensol ^® TO 89), antifreeze (ethylene glycol, propylene glycol). As a tackifier, rosin or hydrocarbon based resins can be used. Other excipients may be, crosslinkers, adhesion promoters (acrylic acid, silanes, aziridines) or defoamers (Lumiten® ^® brands).

The one-component according to the invention Sealant is generally prepared as follows. The dispersion will be presented. The pH of the dispersion should be in one range from 5 to 9, preferably in the range of 7.5 to 8.5, and is optionally adjusted with sodium hydroxide or ammonia.

The further components (ii) to (viii) can be added in this order be added. Subsequently, will the mixture about 10 minutes in the planetary mixer, horizontal turbulent Mixer (Drais), planetary dissolver or dissolver (PC Laboratory Systems) mixed, preferably at reduced pressure, more preferably at 80 to 200 mbar.

The Application of one-component sealant is without special equipment for everyone easily possible.

The one-component according to the invention Sealant can in cartridges, foil bags, buckets, tubes or pressure vessels according to TRG 300 be packed.

The Applied one-component sealant can be because of its creamy Easily equalize consistency.

she can be used for sealing, gluing, coating, and filling, in particular for gluing constructions made of wood, ceramics, glass, cement, Metal, plastics and plastic films. The layer thickness can up to 30 mm, in particular 1 to 20 mm.

The peel adhesion the one-component according to the invention Sealants is in the dry state, preferably greater than 0.2 N / mm, more preferably greater than 0.5 N / mm. The peel adhesion can be measured according to DIN EN 1939, for example.

The one-component according to the invention Sealants are resistant to aging when dry, The peel adhesion is preferred after storage for at least two weeks greater than 0.2 N / mm, more preferably greater than 0.5 N / mm.

Of the Proportion of volatile organic contaminants in the sealant of the invention is in wet condition below 200 ppm by weight, preferably below 100 ppm by weight, more preferably below 50 ppm by weight. Volatile organic compounds are organic compounds with a vapor pressure of at least 0.1 mbar at 20 ° C. The content can be determined by gas chromatography.

The viscosity the sealant of the invention is preferably 50 to 5000 Pas, more preferably 200 to 1000 Pas. The viscosity can be measured according to DIN EN ISO 3219, for example.

Of the Wet state of the sealant is the condition immediately after Production or immediately before use. Usually sealants are dehydrated between manufacture and use protected.

Of the Dry state of the sealant is the condition that the sealant when stored at 23 ° C and a relative humidity of 50% after at least one week, preferably reached after two weeks, at least on their surface. The stickiness the dry sealant can be easily sensed by touch, for example with a finger. Of course, in the Patent Application DE-A-100 00 940 described the test with the current Ball be applied. In this case, the path of the ball is on the dry sealant according to the invention preferably at most 30 cm, more preferably at most 20 cm.

The one-component sealants of the invention are particularly suitable for sealing and / or connecting materials, such as beech wood, polyolefins such as polyethylene, polypropylene and polyisoprene, polyesters such as polycondensates of bisphenol A and phthalic acid, polyethylene terephthalate and polyhydroxybenzoate and fiber cement boards such as Fulguplan ^® 160, (available on Rocholl GmbH, DE) Internit ^® Eternit ^® Glasal and Eterplan ^® N, more preferably of polyolefin films, polyester films, and fiber cement slabs, are very particularly preferably polyethylene films and fiber cement slabs.

The Composites consisting of a fiber cement board, a polyolefin and / or polyester film and the single-component sealing compound according to the invention stand out after drying by a high firmness and aging resistance out.

The one-component according to the invention Sealants have improved peel adhesion, in particular Fiber cement boards, are resistant to aging, in the dry state self-adhesive as well as in the wet state largely free from volatile organic compounds.

The Examples below are intended to illustrate the invention in more detail, but without it to restrict.

Example 1:

48 parts by weight Luphen D ^® 259 U (polyurethane dispersion) was mixed with 24 parts by weight DRT ^® P 0210 (resin), 0.05 parts by weight Luconylblau ^® 6900 (Pigment) 24.45 parts by weight of quartz sand of grain size from 0.08 to 0.4 mm (filler ), 2.9 parts by weight of Aerosil ^® 200 (thixotropic agent) and 0.6 parts by weight Collacral ^® C (thickener) at 25 ° and 100 mbar mixed.

On a fiber cement board Fulguplan ^® 160 (available from Rocholl GmbH, DE) an area of 10 × 5 cm is drawn. The sealant to be tested is applied with a toothed blade (2 mm) and covered with the polyester or polyethylene film. Then the foil is rolled up with a weight of 2.5 kg. After two weeks storage at 23 ° C and a relative humidity of 50% is tested at a test speed of 100 mm / min (roller peeling device).
Luphen ^® D 259 U is an aqueous dispersion of a polyether polyurethane elastomer from BASF Aktiengesellschaft
Luconylblau® 6900 is a pigment of BASF Aktiengesellschaft
Aerosil ^® 200 is a Degussa silica powder
Collacral ^® C is an emulsified in an aliphatic petroleum fraction acrylic acid-acrylamide copolymer of BASF Aktiengesellschaft

Example 2:

40 parts by weight Luphen ^® D 259 U (polyurethane dispersion) was mixed with 20 parts by weight Aquatac ^® 6085 B 1 (resin), 15.35 parts by weight Bremasin ^® 1205 (resin), 0.65 parts by weight Luconylblau ^® 6900 (Pigment) 20.65 parts by weight of silica sand the grain size of 0.08 to 0.4 mm is mixed mbar (filler), 2.65 parts by weight of Aerosil ^® 200 (thixotropic agent) and 0.7 parts by weight Collacral ^® C (thickener) at 25 ° to 100.

The peel adhesion was tested analogously to Example 1.
Aquatac ^® 6085 B 1 is a resin dispersion Arizona Chemical
Bremasin ^® 1205 is a liquid resin from Lackharzwerke Robert Krämer

Example 3:

40 parts by weight Luphen ^® D 259 U (polyurethane dispersion) was mixed with 20 parts by weight Aquatac ^® 6085 B 1 (resin), 15.35 parts by weight acResin ^® DS 3500 (acrylic soft resin), 0.05 parts by weight Luconylblau ^® 6900 (pigment), 21, 25 parts by weight of quartz sand of grain size 0.08 to 0.4 mm is mixed mbar (filler), 2.65 parts by weight of Aerosil ^® 200 (thixotropic agent) and 0.7 parts by weight Collacral ^® C (thickener) at 25 ° to 100.

The peel adhesion was tested analogously to Example 1.
acResin ^® DS 3500 is a carboxyl group-containing polybutyl acrylate from BASF Aktiengesell- schaft

Example 4 (comparative example)

Analogously to Example 1, the peel adhesion of Siga Primur ^® (Sigu Cover AG, CH), a sealing compound based on a polyacrylate dispersion according to DE-A-100 00 940, tested.

Table 1:

Claims (10)

One-component sealant based on a polyurethane dispersion which is self-adhesive in the dry state. Sealant according to claim 1, the content of volatile organic compounds in the wet state less than 100 ppm by weight is. Sealant according to a the claims 1 and 2, which in the dry state a peel adhesion of more than 0.2 N / mm having. Sealant according to a the claims 1 to 3, wherein the polyurethane dispersion has a solids content of 30 to 70 wt .-% has. Sealant according to a the claims 1 to 4, which has a pH of 5 to 9. Sealant according to a the claims 1 to 5, which in the wet state at 23 ° C has a viscosity of at least 50 Pas. Composite of wood and / or a fiber cement board, a sealant according to a the claims 1 to 6 and a polyolefin and / or polyester film. Use of the one-component sealant according to one the claims 1 to 6 for sealing and / or connecting materials. Use according to claim 8, wherein one of the materials is a polyolefin, a polyester, a Polyolefin film or polyester film. Use according to any one of claims 8 and 9, wherein one of the materials is wood or fiber cement is.