Process for the preparation of latices based on polychloroprene and use thereof as adhesives

Abstract

A process is described for the preparation of latices based on polychloroprene, comprising the polymerization of chloroprene in the presence of a first latex essentially consisting of polymeric particles produced in a first polymerization of a composition of monomers comprising (a) alpha-, beta-unsaturated carboxylic acids and/or derivatives thereof, (b) vinyl aromatic compounds, (c) conjugated dienes; said first latex having a content of alpha-, beta-unsaturated carboxylic acids, expressed as parts of alpha-, beta-unsaturated carboxylic acids per 100 grams of polymeric particles, ranging from 1 to 15%, thus obtaining a final latex, the solid particles of said final latex having an quantity of chloroprene ranging from 50 to 95% by weight, preferably from 80 to 95% by weight.

1 . A process for the preparation of latices based on polychloroprene; comprising the polymerization of chloroprene in the presence of a first latex essentially consisting of polymeric particles produced in a first polymerization of a composition of monomers comprising (a) α,β-unsaturated carboxylic acids and/or derivatives thereof, (b) vinyl aromatic compounds, (c) conjugated dienes; said first latex having a content of α,β-unsaturated carboxylic acids, expressed as parts of α,β-unsaturated carboxylic acids per 100 grams of polymeric particles, ranging from 1 to 15%; thus obtaining a final latex, the solid particles of said final latex having an quantity of chloroprene ranging from 50 to 95% by weight.  
     
     
         2 . The process according to  claim 1 , wherein the first latex has a content of α,β-unsaturated carboxylic acids ranging from 2% to 8%.  
     
     
         3 . The process according to  claim 1 , wherein the first latex essentially consists of polymeric particles deriving from a first polymerization of a composition of monomers comprising (a) α,β-unsaturated carboxylic acids and/or derivatives thereof, in a quantity ranging from 2% to 25% by weight, (b) vinyl aromatic compounds in a quantity ranging from 40 to 60% by weight, (c) conjugated dienes in a quantity ranging from 20% to 55%, the sum of components (a)+(b)+(c) being equal to 100, on the condition that the amount of α,β-unsaturated carboxylic groups is that defined above.  
     
     
         4 . The process according to  claim 3 , wherein the composition of monomers comprises (a) α,β-unsaturated carboxylic acids and/or derivatives thereof, in a quantity ranging from 5% to 22% by weight, (b) vinyl aromatic compounds in a quantity ranging from 42 to 48% by weight, (c) conjugated dienes in a quantity ranging from 30% to 40% by weight.  
     
     
         5 . The process according to  claim 1 , wherein the vinyl-aromatic compound is styrene.  
     
     
         6 . The process according to  claim 1 , wherein the diene is 1,3-butadiene.  
     
     
         7 . The process according to  claim 1 , wherein the α,β-unsaturated carboxylic acids and their derivatives are selected from (i) salts of alkaline metals of (meth)acrylic acid and (ii) acrylonitrile.  
     
     
         8 . The process according to  claim 1 , wherein the first latex can also contain chloroprene, in a quantity however not exceeding 15%.  
     
     
         9 . The process according to  claim 8 , wherein the first latex can also contain chloroprene, in a quantity however not exceeding 10%.  
     
     
         10 . The process according to  claim 1 , wherein the solid particles of the final latex have a chloroprene content ranging from 80 to 95% by weight.  
     
     
         11 . Use of the latices prepared according to  claim 1  in the preparation of adhesives.  
     
     
         12 . Use of the latices according to  claim 10 , in the preparation of cotton/cotton, wood/wood and wood/formica adhesives.