The invention relates to an adhesive. Provision is made for the adhesive to comprise (a) 50 to 95% by weight of a heat-activable or pressure-sensitively adhesive polymer formed from a comonomer mixture comprising, based on the polymer, (a1) 40 to 95% by weight of acrylic and/or methacrylic esters of the formula CH 2 ═CH(R 1 )(COOR 2 ), where R 1 is H and/or CH 3 and R 2 is H and/or alkyl chains having 1 to 30 carbon atoms; (a2) 5 to 30% by weight of a first copolymerizable vinyl monomer containing at least one carboxylic and/or sulphonic and/or phosphonic acid group; (a3) 1 to 10% by weight of a second copolymerizable vinyl monomer containing at least one epoxy group or one acid anhydride function; and (a4) 0 to 20% by weight of a third copolymerizable vinyl monomer containing at least one functional group which differs from the functional group of the first copolymerizable vinyl monomer and from the functional group of the second copolymerizable vinyl monomer; and also (b) 5 to 50% by weight of an epoxy resin or a mixture of two or more epoxy resins.
1. Adhesive comprising, based on the adhesive,
(a) 50 to 95% by weight of a heat-activable or pressure-sensitively adhesive polymer formed from a comonomer mixture consisting essentially of, based on the polymer,
(a1) 40 to 94% by weight of acrylic and/or methacrylic esters of the formula CH 2 ═CH(R 1 )(COOR 2 ), where R 1 is H or CH 3 and R 2 is H or alkyl chains having 1 to 30 carbon atoms;
(a2) 5 to 30% by weight of a first copolymerizable vinyl monomer containing at least one carboxylic and/or sulphonic and/or phosphonic acid group;
(a3) 1 to 10% by weight of a second copolymerizable vinyl monomer containing at least one epoxy group or one acid anhydride function; and
(a4) 0 to 20% by weight of a third copolymerizable vinyl monomer containing at least one functional group which differs from the functional group of the first copolymerizable vinyl monomer and from the functional group of the second copolymerizable vinyl monomer; and also
(b) 5 to 50% by weight of an epoxy resin or a mixture of two or more epoxy resins.
2. Adhesive according to claim 1 , wherein component (a1) is an acrylic or methacrylic ester with an alkyl group containing 4 to 9 carbon atoms.
3. Adhesive according to claim 1 wherein component (a1) is selected from the group consisting of n-butyl acrylate, n-pentyl acrylate, n-hexyl acrylate, n-heptyl acrylate, n-octyl acrylate, n-nonyl acrylate, lauryl acrylate, stearyl acrylate and behenyl acrylate.
4. Adhesive according to claim 1 , wherein the component (a2) is selected from the group consisting of itaconic acid, acrylic acid, methacrylic acid, vinylacetic acid, fumaric acid, crotonic acid, aconitic acid, dimethylacrylic acid, β-acryloyloxypropionic acid, trichioroacrylic acid, vinyiphosphonic acid and vinylsuiphonic acid.
5. Adhesive according to claim 1 , wherein component (a3) is selected from the group consisting of glycidyl methacrylate, maleic an hydride and itaconic an hydride.
6. Adhesive according to claim 1 , wherein component (a4) is selected from the group consisting of vinyl esters, vinyl ethers, vinyl halides, vinylidene halides and vinyl compounds containing aromatic rings and heterocycles in αposition.
7. Adhesive according to claim 1 , wherein component (a4) is selected from the group consisting of vinyl acetate, vinylformamide, vinylpyridine, ethyl vinyl ether, vinyl chloride, vinylidene chloride and acrylonitrile.
8. Adhesive according to claim 1 , wherein component (b) is an epoxy resin containing at least two epoxy groups.
9. Adhesive according to claim 1 , wherein component (b) is an epoxy resin having a molecular weight of 100 g/mol to 25 000 g/mol.
10. Adhesive tape comprising the adhesive of claim 1 .
11. Adhesive tape according to claim 10 , where the adhesive tape is coated on one or both sides with the adhesive.
12. Adhesive tape according to claim 11 , where the adhesive is crosslinked by means of UV radiation or electron beams.