Latex, fluid treatments for bonding, fibrous members, and composite member consisting of fiber member and vulcanized rubber members

Abstract

A latex of a cyano-bearing copolymer rubber which contains units derived from an α,β-ethylenically unsaturated nitrile monomer in an amount of 10 to 30% by mass and has an iodine number of 250 or below, a Mooney viscosity (ML 1+4 , 100° C.) of 10 to 120, and a difference (ΔTg) between extrapolated glass transition initiation temperature (Tig) and extrapolated glass transition ending temperature (Teg) of 15° C. or below as determined by differential scanning calorimetry; and fluid treatments for bonding and adhesive compositions, containing the latex. The adhesive compositions are excellent in heat resistance, oil resistance, and adhesion to vulcanized rubbers, and exhibit tackiness.

1 . A latex of nitrile group-containing copolymer rubber containing 10 to 30 mass % α,β-ethylenically unsaturated nitrile monomer unit, having an iodine value of 250 or less and a Mooney viscosity (ML 1+4 , 100° C.) of 10 to 120, and showing a temperature difference (ΔTg) of 15° C. or less between extrapolated glass transition initiation temperature (Tig) and extrapolated glass transition end temperature (Teg) measured by differential scanning calorimetry.  
     
     
         2 . The latex according to  claim 1 , wherein the temperature difference (ΔTg) is 14° C. or less.  
     
     
         3 . The latex according to  claim 1  or  2 , wherein the compositional distribution breadth of each monomer unit in the nitrile group-containing copolymer rubber is 80 mass % or less wherein the compositional distribution breadth of each monomer is the ratio of a difference between the maximum and minimum contents of each monomer in a minute part of the polymer to the content of each monomer in the whole polymer.  
     
     
         4 . The latex according to  claim 1 , wherein the compositional distribution breadth of a monomer unit copolymerizable with the α,β-ethylenically unsaturated nitrile monomer is 80 mass % or less wherein the compositional distribution breadth of each monomer is the ratio of a difference between the maximum and minimum contents of each monomer in a minute part of the polymer to the content of each monomer in the whole polymer.  
     
     
         5 . The latex according to  claim 1 , wherein the content of the α,β-ethylenically unsaturated nitrile monomer unit in the nitrile group-containing copolymer rubber is 12 to 25 mass %.  
     
     
         6 . The latex according to  claim 1 , wherein the iodine value of the nitrile group-containing copolymer rubber is 200 or less.  
     
     
         7 . The latex according to  claim 1 , wherein the average particle diameter of the nitrile group-containing copolymer rubber is 50 to 150 μm.  
     
     
         8 . An adhesive treatment solution comprising the latex according to  claim 1  and a resorcinol/formaldehyde resin.  
     
     
         9 . The treatment solution according to  claim 8 , wherein the amount of the resorcinol/formaldehyde resin incorporated into 100 parts by weight of the nitrile group-containing copolymer rubber dispersed in the latex is 3 to 60 parts by weight.  
     
     
         10 . An adhesive composition comprising a resorcinol/formaldehyde resin and nitrile group-containing copolymer rubber particles containing 10 to 30 mass % α,β-ethylenically unsaturated nitrile monomer unit, having an iodine value of 250 or less and a Mooney viscosity (ML 1+4 , 100° C.) of 10 to 120, and showing a temperature difference (ΔTg) of 15° C. or less between extrapolated glass transition initiation temperature (Tig) and extrapolated glass transition end temperature (Teg) measured by differential scanning calorimetry.  
     
     
         11 . The adhesive composition according to  claim 10 , wherein the amount of the resorcinol/formaldehyde resin incorporated into 100 parts by weight of the nitrile group-containing copolymer rubber particles is 3 to 60 parts by weight.  
     
     
         12 . The adhesive composition according to  claim 10  or  11 , wherein the water content in the composition is 1 mass % or less.  
     
     
         13 . A fiber member comprising a layer of the adhesive composition according to  claim 10  formed on at least a part of the surface of a fiber member.  
     
     
         14 . The fiber member according to  claim 13 , wherein the thickness of the adhesive composition layer after drying is 0.1 to 10 μm.  
     
     
         15 . The fiber member according to  claim 13 , wherein the fiber constituting the fiber substrate is selected from the group consisting of glass fiber, polyester fiber, polyamide fiber and polybenzobisoxazole.  
     
     
         16 . A method of producing a fiber member, which comprises applying and drying the adhesive treatment solution according to  claim 8  on at least a part of the surface of a fiber substrate.  
     
     
         17 . A composite member comprising the fiber member according to  claim 13  adhesive-bonded to a vulcanized rubber member.  
     
     
         18 . A method of producing a fiber member/vulcanized rubber composite member, which comprises bringing a vulcanizable rubber composition into contact with an adhesive composition layer formed on the surface of the fiber member according to  claim 13  and then vulcanizing it.