Adhesive and its use
The invention relates to the use of a two-phase polymer combination which is dissoluble in aqueous alkali and comprises a. an alkali-soluble copolymer or terpolymer of an α,β-unsaturated monocarboxylic acid which possesses carboxyl groups distributed essentially uniformly over the chain of the molecule, as a continuous phase, and b. a copolymer or terpolymer which is insoluble in aqueous alkali and contains epoxy groups along its polymer chain, as a discontinuous finely disperse phase, c. free epoxy groups on the surface of the polymer particles of the discontinuous phase being linked to one another by esterification with some of the carboxyl groups of the polymer of the continuous phase, and the remaining carboxyl groups being present in unchanged form, as an adhesive. The polymer combination, which is not tacky in the dry state, can be made tacky by supplying aqueous moisture to it.
1. A method for bonding a two-phase polymer combination dissoluble in aqueous alkali to a surface of at least one substrate, said two-phase polymer combination consisting essentially of
a. an alkali-soluble copolymer or terpolymer of an α, β-unsaturated monocarboxylic acid which possesses carboxyl groups distributed essentially uniformly over the chain of the molecule, as a continuous phase, and
b. a copolymer or terpolymer which is insoluble in aqueous alkali and contains epoxy groups along its polymer chain, as a discontinuous finely disperse phase,
wherein free epoxy groups on the surface of the polymer particles of the discontinuous phase are linked by esterification with some of the carboxyl groups of the polymer of the continuous phase, and the remaining carboxyl groups are present in unchanged form, comprising the steps of:
providing said two-phase polymer combination, supplying aqueous moisture to said polymer combination, and
applying the moist polymer combination to said surface of said at least one substrate; and
wherein the polymer combination is applied in the form of a film.
2. Method according to claim 1 wherein aqueous moisture is supplied to one side of the film to provide it for bonding on said side.
3. Method according to claim 1 wherein aqueous moisture is supplied to both sides of the film to provide it for both-side bonding.
4. Method according to claim 1 wherein aqueous moisture is supplied to the entire area of the film providing it for bonding over its entire area.
5. Method according to claim 1 wherein aqueous moisture is supplied to certain places of the film providing it for bonding only in said places.