NEW SYSTEMS FOR PRIMING AND ADHESION OF FLOORING

1 . A layer structure comprising

at least one primer layer (G) obtained from a polyacrylate primer (AG), wherein the polyacrylate primer (AG) is in the form of an aqueous polymer dispersion, wherein the aqueous polymer dispersion contains water-dispersed polymer particles and is produced by free-radical polymerization of monomers comprising

a) at least 50 percent by weight, based on a total amount of monomers a) to d), of at least one monomer comprising C 1 - to C 20 -alkyl acrylates, C 1 - to C 20 -alkyl methacrylates, vinyl esters of carboxylic acids containing up to 20 carbon atoms, vinylaromatics having up to 20 carbon atoms, vinyl halides, vinyl ethers of alcohols containing 1 to 10 carbon atoms, aliphatic hydrocarbons having 2 to 8 carbon atoms and one or two double bonds, or mixtures of these monomers, and

b) at least 0.1 percent by weight, based on the total amount of monomers a) to d), of at least one monomer having at least one acid group or mixtures of these monomers, and

c) at least 0.1 to 5 percent by weight, based on the total amount of monomers a) to d), of at least one ethylenically unsaturated compound having at least one functional group comprising a keto group or an aldehyde groups

wherein the aqueous polymer dispersion, in addition to the water-dispersed polymer particles, contains at least one compound AH having at least two functional groups that can enter into a crosslinking reaction with the keto groups or with the aldehyde groups,

wherein the molar ratio of the functional groups in compound AH that are reactive with keto groups or with aldehyde groups to the keto and aldehyde groups in monomer b) is 1:10 to 2:1;

d) optionally further monomers and

at least one curable composition based on silane-modified polymers (KS) applied to the primer layer (G), wherein the silane-modified polymers have at least one end group of the general formula (I)

-A n -R—SiVYZ   (I)

in which

A is a divalent binding group containing at least one heteroatom,

R is a divalent hydrocarbyl radical having 1-12 carbon atoms,

V, Y, Z are substituents on the silicon atom that are independently C 1 -C 8 -alkoxy or C 1 -C 8 -acyloxy groups, where

at least one of the V, Y, or Z radicals is a C 1 -C 8 -alkoxy or C 1 -C 8 -acyloxy group, and

n is 0 or 1.

2 . The layer structure as claimed in claim 1 , comprising

at least one primer layer (G) obtained from a polyacrylate primer (AG), wherein the polyacrylate primer (AG) is in the form of an aqueous polymer dispersion, wherein the aqueous polymer dispersion contains water-dispersed polymer particles and is produced by free-radical polymerization of monomers comprising

a) 50 to 90 percent by weight, based on the total amount of monomers a) to d), of at least one monomer comprising methyl methacrylate, methyl acrylate, butyl acrylate, n-butyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, 2-propylheptyl acrylate, n-hexyl acrylate, n-octyl acrylate, hexyl acrylate, octyl acrylate, benzyl (meth)acrylate, isobutyl acrylate, tert-butyl (meth)acrylate, cyclohexyl (meth)acrylate, vinyl laurate, vinyl stearate, vinyl propionate, vinyl versatate, vinyl acetate, vinyltoluene, alpha- and para-methylstyrene, styrene, alpha-butylstyrene, 4-n-butylstyrene, 4-n-decylstyrene, vinyl chloride, vinylidene chloride, vinyl methyl ether, vinyl isobutyl ether or mixtures of these monomers, and

b) 0.5 to 5 percent by weight, based on the total amount of monomers a) to d), of at least one monomer having at least one acid group comprising alpha,beta-monoethylenically unsaturated mono- and dicarboxylic acids, monoesters of alpha,beta-monoethylenically unsaturated dicarboxylic acids, the anhydrides of the aforementioned alpha,beta-monoethylenically unsaturated carboxylic acids or ethylenically unsaturated sulfonic acids, phosphonic acids or dihydrogenphosphates, water-soluble salts thereof, or mixtures of these monomers, and

c) 0.2 to 5 percent by weight, based on the total amount of monomers a) to d), of at least one ethylenically unsaturated compound having at least one functional group comprising a keto group or an aldehyde group, comprising acrolein, methacrolein, vinyl alkyl ketones having 1 to 20 carbon atoms, formylstyrene, alkyl (meth)acrylates having one or two keto or aldehyde groups, or one aldehyde and one keto group, in the alkyl radical, where the alkyl radical preferably comprises 3 to 10 carbon atoms in total, or N-oxoalkyl(meth)acrylam ides of the formula R 6 —C(═O)—R 7 —NH—C(═O)—CR 8 ═CH 2 where R 6 and R 8 are independently hydrogen or a hydrocarbyl group having 1 to 10 carbon atoms, and R7 is a hydrocarbyl group having 2 to 15 carbon atoms,

wherein the aqueous polymer dispersion, in addition to the water-dispersed polymer particles, contains at least one compound AH having at least two functional groups that can enter into a crosslinking reaction with the keto groups or with the aldehyde groups, comprising oxalic dihydrazide, malonic dihydrazide, succinic dihydrazide, carbodihydrazide, glutaric dihydrazide, adipic dihydrazide, sebacic dihydrazide, maleic dihydrazide, fumaric dihydrazide, itaconic dihydrazide, isophthalic dihydrazide, ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, polyethyleneimines, partly hydrolyzed polyvinylformamides, ethylene oxide and propylene oxide adducts of amines, cyclohexanediamine, or xylylenediamine,

where the molar ratio of the functional groups in compound AH that are reactive with keto groups or with aldehyde groups to the keto and aldehyde groups in monomer b) is 1:10 to 2:1,

d) optionally further monomers d) having a proportion of 5 to 15 percent by weight, based on the total amount of monomers a) to d), comprising acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, phenyloxyethylglycol mono(meth)acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 2-am inoethyl (meth)acrylate, tert-butylaminoethyl methacrylate, acrylonitrile, methacrylonitrile, vinyl, allyl or methallyl glycidyl ethers or glycidyl (meth)acrylate, butanediol di(meth)acrylate, allyl methacrylate or hydroxyalkyl (meth)acrylates having 1 to 10 carbon atoms in the alkyl group, and

at least one curable composition based on silane-modified polymers (KS) applied to the primer layer (G), wherein the silane-modified polymers have at least one end group of the general formula (I) in which

A is an oxygen atom or an —NR′— group in which R′ is a hydrogen atom or

an alkyl or aryl radical having 1 to 12 carbon atoms, amide, carbamate, urea, imino, carboxylate, carbamoyl, amidino, carbonate, sulfonate or sulfinate group,

R is a divalent hydrocarbyl radical having 1-6 carbon atoms,

V, Y, Z are substituents on the silicon atom and are each independently a methyl, ethyl, methoxy or ethoxy group, where at least one of the V, Y or Z radicals is a methoxy or ethoxy group,

n is 0 or 1.

3 . The layer structure as claimed in claim 1 , comprising at least one primer layer (G) obtained from a polyacrylate primer (AG), wherein the polyacrylate primer (AG) has a proportion of solvents within the scope of TRGS 610, January 2011 edition, section 2.5, of less than 1%.

4 . The layer structure as claimed in claim 1 , comprising at least one primer layer (G) obtained from a polyacrylate primer (AG), wherein the polyacrylate primer (AG) comprises a polyurethane dispersion having a minimum film formation temperature (measured on a film-forming bench with a temperature gradient, DIN ISO 2115:2001-04) of less than 5° C.

5 . The layer structure as claimed in claim 1 , comprising at least one primer layer (G) obtained from a polyacrylate primer (AG), wherein the polyacrylate primer (AG) comprises further compounds X3Y3 that can react with reactive groups present in the aqueous polymer dispersion, comprising compounds containing carbodiimide groups (carbodiimide crosslinkers) that can react with carboxylic acid groups present in the polymer dispersion.

6 . The layer structure as claimed in claim 1 , wherein the primer layer (G) is obtained by storage of the aqueous layer produced using the polyacrylate primer (AG) for 1 to 72 hours.

7 . A layer system comprising the layer structure of claim 1 , comprising at least one primer layer (G) obtained from a polyacrylate primer (AG) and at least one curable composition based on silane-modified polymers (KS) applied thereto.

8 . A layer system comprising the layer structure of claim 1 , comprising at least one primer layer (G) obtained from a polyacrylate primer (AG) and at least one curable composition based on silane-modified polymers (KS) applied thereto, and substrate bonded thereto, for example floor covering.

9 . A method of bonding floor coverings to pretreated bases using the layer structure of claim 1 , comprising at least one primer layer (G) obtained from a polyacrylate primer (AG) as pretreatment and at least one curable composition based on silane-modified polymers (KS) as adhesive.

10 . The method as claimed in claim 9 , wherein the polyacrylate primer (AG) is applied in one layer.

11 . The method as claimed in claim 9 , wherein a polyacrylate primer (AG) is first applied to a base and a floor covering is subsequently bonded to the base thus pretreated with at least one curable composition based on silane-modified polymers (KS), wherein the curable composition based on silane-modified polymers (KS) is applied between 1-72 h after the application of the polyacrylate primer.

12 . A layer system comprising a base, at least one primer layer (G) obtained from a polyacrylate primer (AG), at least one curable composition based on silane-modified polymers (KS) applied thereto and floor covering bonded thereto, wherein the polyacrylate primer (AG) corresponds to one of the polyacrylate primers (AG) of claim 1 , and the curable composition based on silane-modified polymers (KS) corresponds to the compositions based on silane-modified polymers (KS) of claim 1 .

13 . A method of sealing joins between 2 substrates using the layer structures specified in claim 1 , comprising at least one primer layer (G) obtained from a polyacrylate primer (AG) as pretreatment and at least one curable composition based on silane-modified polymers (KS) as sealing compound.

14 . The method as claimed in claim 13 , wherein a polyacrylate primer (AG) is first applied to at least one of the two surfaces of a join formed by 2 substrates and at least one curable composition based on silane-modified polymers (KS) as sealing compound is subsequently introduced into the join, wherein the curable composition based on silane-modified polymers (KS) is introduced between 1-72 h after the application of the polyacrylate primer to the surface(s) of the join.

15 . A layer system comprising 2 substrates, at least one primer layer (G 1 ) obtained from a polyacrylate primer (AG) on a side of a first substrate that faces the a second substrate and optionally at least one primer layer (G 2 ) obtained from a polyacrylate primer (AG) on a side of the second substrate that faces the first substrate, and at least one curable composition based on silane-modified polymers (KS) disposed between the primer layer G 1 and the second substrate or primer layer G 2 , wherein the polyacrylate primer (AG) corresponds to one of the polyacrylate primers (AG) described in claim 1 and the curable composition based on silane-modified polymers (KS) corresponds to one of the compositions based on silane-modified polymers (KS) described in claim 1 .

16 . A kit of parts comprising the polyacrylate primers (AG) or primer layers (G) and the curable compositions based on silane-modified polymers (KS) specified in claim 1 .