Use in a hydraulic binder composition of a dry-ground calcium carbonate with a copolymer of (meth) acrylic acid and an alkoxy or hydroxy polyalkyleneglycol group

Abstract

The invention resides in the use in a composition with a hydraulic binder base, of a calcium carbonate characterised in that it is obtained by dry-grinding, firstly, and in that it is dry-ground in the presence of a grinding aid agent which is a copolymer of (meth)acrylic acid with a monomer containing an alcoxy or hydroxy polyalkyleneglycol group, secondly. The invention also concerns the compositions with a hydraulic binder base thus obtained.

1 . A dry-ground calcium carbonate for use in a hydraulic binder composition, wherein said carbonate is dry-ground in the presence of a copolymer as a grinding aid agent, and said copolymer comprises:
 a) at least one anionic monomer chosen from among acrylic acid, methacrylic acid and their blends,   b) at least one non-ionic monomer, of formula (I):   
       
         
           
           
               
               
           
         
         where:
 m, n, p and q are integers such that: m, n, p≦150, q≧1, and 5≦(m+n+p)q≦150, 
 R 1  represents hydrogen or a methyl or ethyl radical, 
 R 2  represents hydrogen or a methyl or ethyl radical, 
 R represents a radical containing an unsaturated polymerisable function selected from the group of vinylics, the group of acrylic, methacrylic, and maleic esters, the group of unsaturated acrylurethane, methacrylurethane, α-α′ dimethyl-isopropenyl-benzylurethane, and allylurethane, the group of allylic or vinylic ethers, whether or not substituted, the group of ethylenically unsaturated amides and imides, and the group constituted by acrylamide and methacrylamide, and 
 R′ represents hydrogen or a hydrocarbonated radical with 1 to 40 carbon atoms, 
 
         or a blend of several monomers of formula (I), 
         (c) and optionally at least one other monomer selected from among (meth)acrylic anhydride, (meth)acrylamide, the (meth)acrylic esters, with 1 to 20 carbon atoms in their ester radical, the methyl or ethyl methacrylates, the hydroxylated methacrylates, the aromatic vinylic monomers, the organophosphate monomers, and their blends. 
       
     
     
         2 . The dry-ground calcium carbonate according to  claim 1 , wherein said copolymer comprises, expressed as a percentage by weight of the monomers and the sum of the percentages by weight of all the monomers equals 100%:
 a) 0.5% to 50% of at least one anionic monomer selected from acrylic acid, methacrylic acid and their blends,   b) 50% to 99.5% of at least one non-ionic monomer, of formula (I):   
       
         
           
           
               
               
           
         
         where:
 m, n, p and q are integers such that: m, n, p≦150, q≧1, and 5≦(m+n+p)q≦150, 
 R 1  represents hydrogen or a methyl or ethyl radical, 
 R 2  represents hydrogen or a methyl or ethyl radical, 
 R represents a radical containing an unsaturated polymerisable function selected from the group of vinylics, the group of acrylic, methacrylic, and maleic esters, the group of unsaturated acrylurethane, methacrylurethane, α-α′ dimethyl-isopropenyl-benzylurethane, and allylurethane, the group of allylic or vinylic ethers, whether or not substituted, the group of ethylenically unsaturated amides and imides, and the group constituted by acrylamide and methacrylamide, and 
 R′ represents hydrogen or a hydrocarbonated radical with 1 to 40 carbon atoms, 
 
         or a blend of several monomers of formula (I), and 
         (c) 0% to 50% of at least one other monomer selected from among (meth)acrylic anhydride, (meth)acrylamide, the (meth)acrylic esters with 1 to 20 carbon atoms in their ester radical, the methyl or ethyl methacrylates, the hydroxylated methacrylates, the aromatic vinylic monomers, the organophosphate monomers, and their blends. 
       
     
     
         3 . The dry-ground calcium carbonate according to  claim 1 , wherein said copolymer is in the acidic form and optionally distilled, and is partially or totally neutralised by one or more neutralisation agents having a monovalent or polyvalent cation, where the said agents are selected from ammonia, calcium and magnesium hydroxides and/or oxides, sodium, potassium and lithium hydroxides, and the aliphatic and/or cyclic primary, secondary or tertiary amines. 
     
     
         4 . The dry-ground calcium carbonate according to  claim 1 , wherein said copolymer is obtained by processes of radical polymerisation in solution, in a direct or reverse emulsion, in suspension or precipitation in solvents, in the presence of catalytic systems and chain transfer agents, or by processes of controlled radical polymerisation by nitroxide mediated polymerisation (NMP) or by cobaloximes, by atom transfer radical polymerisation (ATRP), and by controlled radical polymerisation by sulphurated derivatives, chosen from carbamates, dithioesters or trithiocarbonates (RAFT) or xanthates. 
     
     
         5 . The dry-ground calcium carbonate according to  claim 3 , wherein said copolymer may be, before or after the total or partial neutralisation reaction, treated and separated into several phases, according to static or dynamic processes by one or more polar solvents belonging to the group consisting of water, methanol, ethanol, propanol, isopropanol, the butanols, acetone, tetrahydrofuran and their blends. 
     
     
         6 . The dry-ground calcium carbonate according to  claim 1 , wherein 0.05% to 5% by dry weight of the said copolymer relative to the dry weight of calcium carbonate is used during a dry grinding of the said carbonate. 
     
     
         7 . The dry-ground calcium carbonate according to  claim 1 , wherein the hydraulic binder is a cement, a concrete or a mortar. 
     
     
         8 . A hydraulic binder composition comprising the dry-ground calcium carbonate according to  claim 1 .