Method for the controlled radical polymerisation of acrylic acid and the salts thereof, polymers thus obtained and applications thereof

Abstract

The present invention concerns a process for controlled radical polymerisation of acrylic acid and its salts in a reactive medium constituted solely of water The invention also concerns homopolymers and copolymers of acrylic acid obtained by the polymerisation process. Finally, the invention concerns the use of the said homopolymers and copolymers of acrylic acid in fields of industry such as the paper field and in particular the coating of paper and the mass-filling of paper, the oil field, or the fields of paint, water treatment, detergency, ceramics, cements or hydraulic binders, public works, inks and varnishes, sizing of textiles or the finishing of leather.

1 - 8 . (canceled)  
   
   
       9 . A hydrosoluble transfer agent, which is obtained in a polymerization reactive medium, of a process for controlled radical homopolymerization of acrylic acid and its salts, or for copolymerization of acrylic acid with one or more hydrosoluble monomers, 
 said process being performed in an aqueous solution as said polymerization reactive medium,    wherein said process is in batch or semi-batch mode, and    wherein said process comprises two stages, the first of which is synthesizing “in situ” said hydrosoluble transfer agent used in second stage of polymerization.    
   
   
       10 . The hydrosoluble transfer agent according to  claim 9 , wherein said agent is selected from the group consisting of α-substitute β-carboxylate xanthate salts.  
   
   
       11 . A polymer of acrylic acid or of its salts, obtained by a process for controlled radical homopolymerization of acrylic acid and its salts, or for copolymerization of acrylic acid with one or more hydrosoluble monomers, 
 said process being performed in an aqueous solution,    wherein said process is in batch or semi-batch mode, and    wherein said process comprises two stages, the first of which is synthesizing “in situ” a hydrosoluble transfer agent used in the second stage of polymerization.    and wherein said polymer has an average molecular mass by weight (M w ) between 1000 g/mole and 60,000 m/mole, measured by the GPC method, using as a standard, 5 standards of sodium polyacrylate, and wherein said polymer has a polymolecularity index of less than, or equal to, 2, for a conversion rate, relative to acrylic acids higher than 90%, determined according to an HPLC method.    
   
   
       12 . The polymer of acrylic acid or of its salts, according to  claim 11 , wherein said polymer has an average molecular mass by weight (M w ) between 4500 g/mole and 8000 g/mole, measured by the GPC method, using as a standard, 5 standards of sodium polyacrylate, and wherein said polymer has a polymolecularity index of less than, or equal to, 2, for a conversion rate, relative to acrylic acids higher than 90%, determined according to an HPLC method.  
   
   
       13 . The polymer of acrylic acid or of its salts, according to  claim 11 , wherein said polymer is a homopolymer of acrylic acid.  
   
   
       14 . The polymer of acrylic acid or of its salts, according to  claim 11 , wherein said polymer comprises monomeric units derived from at least one hydrosoluble copolymerized monomer selected from the group consisting of methacrylic acid, itaconic acid, maleic acid, 2-acrylamido-2-methyl-1-propane sulphonic acid in acid form or partially neutralized, 2-methacrylamido-2-methyl-1-propane sulphonic acid in acid form or partially neutralized, 3-methacrylamido-2-hydroxy-1-propane sulphonic acid in acid form or partially neutralized, allylsulphonic acid, methallylsulphonic acid, allyloxybenzene sulphonic acid, methallyloxybenzene sulphonic acid, 2-hydroxy-3-(2-propenyloxy)propane sulphonic acid, 2-methyl-2-propene-1-sulphonic acid, ethylene sulphonic acid, propene sulphonic acid, 2-methyl sulphonic acid, styrene sulphonic acid, as well as all their salts, vinyl sulphonic acid, sodium methallylsulfonate, sulfopropyl acrylate or methacrylate, sulfomethylacrylamide, sulfomethylmethacrylamide acrylamide, methylacrylamide, n-methylolacrylamide, n-acryloylmorpholine, ethylene glycol methacrylate, ethylene glycol acrylate, propylene glycol methacrylate, propylene glycol acrylate, propene phosphonic acid, ethylene or propylene glycol acrylate or methacrylate phosphate, vinylpyrrolidone, methacrylamido propyl trimethyl ammonium chloride or sulphate, trimethyl ammonium ethyl chloride or sulphate methacrylate, as well as their acrylate or acrylamide counterparts, whether quaternised or not, ammonium dimethyldiallylchloride, and mixtures thereof.  
   
   
       15 . The polymer of acrylic acid or its salts, according to  claim 11 , wherein said polymer is in its acid form, or is totally or partially neutralized by one or more monovalent, divalent, trivalent neutralization agents, neutralization agents of higher valency, or mixtures thereof.  
   
   
       16 . The polymer of acrylic acid or its salts, according to  claim 15 , wherein said polymer is partially or totally neutralized, and wherein the monovalent agents are selected from the group consisting of compounds containing alkaline cations, and compounds containing ammonium, or primary or secondary aliphatic and/or cyclic amines, neutralization agents, or agents of higher valency, are selected from the group consisting of compounds containing divalent cations belonging to the alkaline earths, compounds containing trivalent cations, and compounds containing cations of higher valency.  
   
   
       17 . The polymer of acrylic acid and of its salts, according to  claim 16 , wherein said polymer is a homopolymer of acrylic acid, which is totally neutralized by soda, or totally neutralized by a soda-lime mixture in a 50/50 molar ratio, or partially neutralized by a soda-lime mixture in a 50/40 molar ratio.  
   
   
       18 . A composition, comprising the polymer according to  claim 11 , and one or more additives, and 
 wherein the composition is selected from the group consisting of a composition for paper coating and mass-filling of paper, a composition for oil, a composition for paint, a composition for water treatment, a composition for detergency, a composition for ceramics, a composition for cements and/or hydraulic binders, a composition for public works, a composition for inks and/or varnishes, a composition for sizing of textiles and/or finishing of leather, and a composition for a dispersant and/or grinding aid agent of mineral materials.    
   
   
       19 . An aqueous suspension, comprising the polymer according to  claim 11  and one or more mineral fillers, and wherein the polymer is present in an amount from 0.05% to 5% by dry weight, relative to the total dry weight of the one or more mineral fillers.  
   
   
       20 . The aqueous suspension according to  claim 19 , wherein the one or more mineral fillers are selected from the group consisting of natural calcium carbonate, synthetic calcium carbonate, dolomites, magnesium hydroxide, kaolin, talc, gypsum, titanium oxide, and aluminum hydroxide.  
   
   
       21 . A manufactured and/or coated paper, comprising the aqueous suspension according to  claim 19 , and one or more paper additives.  
   
   
       22 . A paint formulation, comprising the aqueous suspension according to  claim 19 , and one or more paint additives.  
   
   
       23 . A method of coating or filling paper, comprising, contacting a composition, comprising the polymer of  claim 11 , with a paper substrate or one or more paper additives.  
   
   
       24 . A method of treating mineral materials, comprising contacting a composition, comprising the polymer of  claim 11 , with one or more mineral materials.