Liquid resin composition for abrasive articles

Abstract

The invention relates to a thermally curable liquid resin composition intended for manufacturing abrasives that comprises at least one epoxy resin comprising at least two epoxy groups and at least one reactive diluent, said composition having a viscosity, at 25° C., less than or equal to 7000 mPa.s. Application of the resin composition for producing abrasive articles, especially bonded abrasives and coated abrasives. It also relates to the abrasive articles comprising abrasive grains connected by such a liquid resin composition.

1 . A thermally curable liquid resin composition intended for manufacturing abrasives, comprising at least one resin comprising at least two epoxy groups and at least one reactive diluent, wherein said composition has a viscosity, at 25° C., less than or equal to 7000 mPa.s. 
     
     
         2 . The composition according to  claim 1 , wherein the resin has a viscosity less than or equal to 6000 mPa.s. 
     
     
         3 . The composition according to  claim 1 , wherein the epoxy resin has an epoxide equivalent weight that varies from 160 to 700. 
     
     
         4 . The composition according to  claim 1 , wherein the epoxy resin is chosen from the epoxy resins of which the main chain is aliphatic, cycloaliphatic or aromatic. 
     
     
         5 . The composition according to  claim 4 , wherein the resin is an aromatic resin. 
     
     
         6 . The composition according to  claim 5 , wherein the resin is a bisphenol A or F diglycidyl ether of formula: 
       
         
           
           
               
               
           
         
         in which n=0-10, and R═H or CH 3 . 
       
     
     
         7 . The composition according to  claim 1 , wherein the epoxy resin is chosen from epoxidized novolac resins. 
     
     
         8 . The composition according to  claim 7 , wherein the novolac is obtained by the reaction of a phenolic compound and an aldehyde in an aldehyde/phenol molar ratio which varies from 0.2 to less than 1. 
     
     
         9 . The composition according to  claim 7 , wherein the epoxy resin corresponds to the formula: 
       
         
           
           
               
               
           
         
       
       with R′═H or 
       
         
           
           
               
               
           
         
       
       in which R═H or CH 3 , and n′=0. 
     
     
         10 . The composition according to  claim 1 , wherein the epoxy resin represents at least 30% by weight of the resin composition, and does not exceed 90%. 
     
     
         11 . The composition according to  claim 1 , wherein the reactive diluent has a viscosity, measured at 25° C., of less than or equal to 1000 mPa.s. 
     
     
         12 . The composition according to  claim 1 , wherein the reactive diluent contains at least one hydroxy, aldehyde, epoxy, oxazolidine or lactone functional group. 
     
     
         13 . The composition according to  claim 12 , wherein the reactive diluent is chosen from saturated or unsaturated alicyclic alcohols, saturated or unsaturated cyclic alcohols, mononuclear or polynuclear aromatic alcohols, glyoxal, glycidyl ethers of saturated or unsaturated alcohols, epoxidized fatty acids, oxazolidines and lactones. 
     
     
         14 . The composition according to  claim 1 , wherein the reactive diluent is chosen from furfuryl alcohol, cardols and derivatives thereof (CNSL), glyoxal, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, epoxidized cardanols, bisoxazolidines and gamma-butyrolactone. 
     
     
         15 . The composition according to  claim 1 , wherein the reactive diluent represents at least 10% by weight of the resin composition, and does not exceed 70%. 
     
     
         16 . The composition according to  claim 1 , wherein it also incorporates at least one crosslinking agent and/or one crosslinking catalyst. 
     
     
         17 . The composition according to  claim 16 , wherein the crosslinking agent is chosen from compounds incorporating at least one amine, hydroxy, aldehyde or carboxylic functional group, and heterocyclic compounds that have a structure incorporating a nitrogen atom and an oxygen atom separated by a carbon atom. 
     
     
         18 . The composition according to  claim 17 , wherein the crosslinking agent is chosen from aliphatic amines, polyamidoamines, aromatic amines, tris(hydroxymethyl)nitromethane, resins containing condensates obtained by Mannich reaction of a phenolic compound, an aldehyde and an amino alcohol, glyoxal and derivatives thereof, 2,2-dimethoxyethanal, acrylic acid homopolymers and copolymers, 1,3-phenylenebisoxazoline, 3-ethyl-2-methyl-2-(3-methylbutyl)-1,3-oxazolidine and 1-aza-3,7-dioxa(5-ethyl)bicyclo[3.3.0]octane. 
     
     
         19 . The composition according to  claim 16 , wherein the crosslinking agent does not exceed 50% of the weight of the liquid resin composition. 
     
     
         20 . The composition according to  claim 16 , wherein the crosslinking catalyst is chosen from the Lewis bases selected from the group consisting of O-(dimethylaminoethyl)phenol, tris(dimethylaminoethyl)phenol, 2,4,6-tri(dimethylaminomethy)phenol, 2-methylimidazole, 2-ethyl-4-methylimidazole and 1-benzyl-2-methylimidazole, and a Lewis acid selected from a boron trifluoride-monoethylamine complex. 
     
     
         21 . The composition according to  claim 16 , wherein the amount of crosslinking catalyst in the liquid resin composition is less than or equal to 10 parts by weight per 100 parts by weight of epoxy resin, reactive diluent and, optionally, crosslinking agent. 
     
     
         22 . An abrasive article comprising abrasive grains connected by a binder based on a thermosetting resin, wherein the binder is the product of the crosslinking of the liquid resin composition according to  claim 1 . 
     
     
         23 . The article according to  claim 22 , wherein the abrasive grains are grains made of alumina, including therein fused aluminas and sintered aluminas obtained by the sol-gel process, which may or may not be seeded by a material of the same crystalline nature, and which may or may not be chemically modified, of iron oxide, molybdenum oxide, vanadium oxide, alumina-zirconia, boron-alumina, silicon carbide, aluminium oxynitride, diamond or cubic boron nitride, and mixtures of such grains. 
     
     
         24 . The article according to  claim 23 , wherein the abrasive grains are treated with an organic compound that contains silicon, selected from the group consisting of silanes functionalized by organic groups. 
     
     
         25 . The article according to  claim 24 , wherein the silane is a vinylsilane, an aminosilane, or an epoxysilane. 
     
     
         26 . The article according to  claim 22 , wherein it is a bonded abrasive. 
     
     
         27 . The article according to  claim 22 , wherein it is a coated abrasive.