Adhesive and its use

Abstract

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 . An adhesive composition dissoluble in aqueous alkali, comprising ing 
 a two-phase polymer combination being capable to form an adhesive bond to substrates in moist state whereas being non-tacky in dry state and    said 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,    wherein the adhesive composition can be made tacky by addition of aqueous moisture.    
     
     
         2 . Adhesive composition according to  claim 1  wherein the aqueous moisture is provided in form of an aqueous liquid.  
     
     
         3 . Adhesive composition according to  claim 1  wherein the polymer combination is in the form of a film.  
     
     
         4 . Adhesive composition according to  claim 3  wherein the film is provided for bonding on at least one side.  
     
     
         5 . Adhesive composition according to  claim 3  wherein the film is provided for bonding over its entire area.  
     
     
         6 . Adhesive composition according to  claim 3  wherein the film is provided for bonding only in part.  
     
     
         7 . Adhesive composition according to  claim 3  wherein the film is transparent to milky.  
     
     
         8 . Adhesive composition according to  claim 3  wherein the film is comprising pigments.  
     
     
         9 . Adhesive composition according to  claim 3  wherein the film is printed.  
     
     
         10 . Adhesive composition according to  claim 3  wherein the film is a detachable label.  
     
     
         11 . Adhesive composition according to  claim 3  wherein the film is a protective film for smooth surfaces such as glass, metal, plastic and also coated surfaces.  
     
     
         12 . Adhesive composition according to  claim 3  wherein the film is a coating.  
     
     
         13 . Adhesive composition according to  claim 12  wherein the film is a protective coating against graffitiy.  
     
     
         14 . Adhesive composition according to  claim 1  wherein the adhesive composition bonded to substrates is removable without residue from the substrates by sufficient addition of water.  
     
     
         15 . Adhesive composition according to  claim 1  wherein the polymer combination is in the form of particles.  
     
     
         16 . Adhesive composition according to  claim 15  wherein the polymer combination is in the form of an aqueous dispersion.  
     
     
         17 . Adhesive composition according to  claim 1  wherein it is processable as a hot-melt adhesive.  
     
     
         18 . Adhesive composition according to  claim 1  wherein it is processable in a multi-stage adhesion process in which the polymer combination is bonded moist and in a further step bonded hot.  
     
     
         19 . Adhesive composition according to  claim 1  wherein it is processable as an adhesive in laminating operations.  
     
     
         20 . Adhesive composition according to  claim 1  wherein it is an interlayer between at least two layers of a composite.  
     
     
         21 . 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.    
     
     
         22 . Method according to  claim 21  wherein the aqueous moisture is provided in form of an aqueous liquid.  
     
     
         23 . Method according to  claim 21  wherein the application of the moist polymer combination is followed by a drying phase.  
     
     
         24 . Method according to  claim 21  wherein the polymer combination is applied in the form of a film.  
     
     
         25 . Method according to  claim 24  wherein aqueous moisture is supplied to one side of the film to provide it for bonding on said side.  
     
     
         26 . Method according to  claim 24  wherein aqueous moisture is supplied to both sides of the film to provide it for both-side bonding.  
     
     
         27 . Method according to  claim 24  wherein aqueous moisture is supplied to the entire area of the film providing it for bonding over its entire area.  
     
     
         28 . Method according to  claim 24  wherein aqueous moisture is supplied to certain places of the film providing it for bonding only in said places.  
     
     
         29 . Method according to  claim 21  wherein the polymer combination is provided in the form of particles.  
     
     
         30 . Method according to  claim 29  wherein the polymer combination is applied in the form of an aqueous dispersion.  
     
     
         31 . Method according to  claim 21 , comprising a further step in which the polymer combination is bonded as a hot melt under heat subsequent to the application of the moist polymer combination.  
     
     
         32 . A method to remove a two-phase polymer combination bonded to a substrate from said substrate without residue, 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 step of:    supplying aqueous moisture to said bonded polymer combination.