Preparation of particles by hydrolysis of a metal cation in the presence of a polymer

Abstract

A subject matter of the invention is a process for the preparation of particles comprising at least one metal ion, which comprises the stage of bringing into contact a precursor a metal cation, optionally partially hydrolyzed, with at least one water-soluble comb copolymer. The invention also relates to the use of such particles in the mechanical polishing of hard objects, in the preparation of pigments or mixed ceramics for the electronic industry, in the reinforcing of polymeric matrices, in fungicidal or biocidal dispersions, in the scavenging of sulfur derivatives or the scavenging of unpleasant smells and to the use of such particles in the mechanical polishing of hard objects, in the preparation of pigments or mixed ceramics for the electronics industry.

1 - 28 . (canceled)  
     
     
         29 . A process for the preparation of particles comprising at least one copper ion which comprises the following stages: 
 a) at least one precursor comprising a copper cation is dissolved or dispersed in an aqueous medium, wherein said precursor is in the form of an aqueous solution of a water-soluble salt of copper;    b) a partial hydrolysis of said precursor is optionally carried out,    c) the precursor resulting from stage a) or the partially hydrolyzed precursor resulting from stage b) is brought into contact with at least one water-soluble comb copolymer comprising either a complexing anionic backbone and stabilizing hydrophilic side chains or a stabilizing hydrophilic neutral backbone and complexing anionic side chains or at least one of the two abovementioned copolymers in combination with at least one complexing anionic hydrophilic polymer; and    d) a partial or complete hydrolysis of the product obtained during stage c) is carried out.    
     
     
         30 . A process according to  claim 29 , wherein the salt of copper is selected from the group consisting of nitrates, sulfates, chlorides, and phosphates.  
     
     
         31 . A process according to  claim 29 , wherein the precursor is in the form of an aqueous dispersion of particles or of aggregates of particles comprising a hydroxide, a hydroxide oxide or a partially hydrolyzed water-soluble salt of a copper cation, optionally combined with an oxide of a metal copper.  
     
     
         32 . A process according to the  claim 31 , wherein the particles or the aggregates have a mean size of less than or equal to  100  nm.  
     
     
         33 . A process according to the  claim 32 , wherein the particles or the aggregates have a mean size of between 2 and 100 nm.  
     
     
         34 . A process according to  claim 29 , wherein the hydrolyses of stage b) and that of stage d) are carried out in the presence of a base which is an alkali metal hydroxide, an alkaline earth metal hydroxide, or aqueous ammonia.  
     
     
         35 . A process according to  claim 34 , wherein the base is chosen from sodium hydroxide, potassium hydroxide, calcium hydroxide or aqueous ammonia, alone or as mixtures.  
     
     
         36 . A process according to  claim 29 , wherein the base employed during optional stage b), and during stage d) corresponds to 50 to 130% of a stoichiometric amount needed to completely hydrolyze the precursor.  
     
     
         37 . A process according to  claim 36 , wherein, n 1  moles of base are being employed during stage b), n 2  moles of base are being employed during stage d) and n represents the sum of n 1  and n 2 , n 1  being non zero, then n 1  and n 2  conform to the following inequalities 0<n 1 ≦0.8 n and 0.2 n≦n 2 <n.  
     
     
         38 . A process according to  claim 29 , wherein the water-soluble comb copolymer, optionally combined with the water-soluble polymer, is chosen so that the comb copolymer, optionally combined with the hydrophilic polymer, forms a transparent solution at 10% by weight in water at a temperature which is the lowest temperature to which said comb copolymer, optionally combined with the hydrophilic polymer, is subjected in the process.  
     
     
         39 . A process according to  claim 38 , wherein the weight-average molecular mass (Mw) of the comb copolymer is between 2 000 and 5×10 5  g/mol.  
     
     
         40 . A process according to  claim 39 , wherein the water-soluble comb copolymer comprises a complexing anionic hydrophilic backbone and nonionic stabilizing hydrophilic side chains, said backbone being obtained from monomers chosen from unsaturated monocarboxylic acids, unsaturated polycarboxylic acids or their anhydride form, or unsaturated sulfonic acids, optionally in combination with one or more water-insoluble monomers.  
     
     
         41 . A process according to  claim 40 , wherein the monomers forming the nonionic side chains are macromonomer entities selected from the group consisting of macromonomers of poly(ethylene glycol)(meth)acrylate, poly(vinyl alcohol)(meth)acrylate, poly(hydroxy(C 1 -C 4 )alkyl(meth)acrylate)(meth)acrylate, poly(N-methylolacrylamide)(meth)acrylate and poly((meth)acrylamide)(meth)acrylate).  
     
     
         42 . A process according to  claim 41 , wherein the nonionic side chains exhibit a poly(ethylene glycol) number-average molar mass of between 200 and 10 000 g/mol.  
     
     
         43 . A process according to  claim 41 , wherein the copolymer comprises a stabilizing hydrophilic neutral backbone and complexing anionic hydrophilic side chains, said neutral backbone being obtained from ethylene oxide in the form of an oligomer or of a polymer.  
     
     
         44 . A process according to  claim 43 , wherein the side chains are obtained from monomers selected from the group consisting of unsaturated carboxylic acids, polycarboxylic acids, anhydride form of polycarboxylic acids, unsaturated amino acids and unsaturated sulfonic acids.  
     
     
         45 . A process according to  claim 43 , wherein the monomers forming the complexing anionic backbone or the complexing anionic side chains are combined with, or partially substituted by, esters of unsaturated carboxylic acids, optionally carrying a sulfonated group or a hydroxyl group; esters of unsaturated carboxylic acid; linear or branched hydrocarbonaceous monomers comprising at least one carbon-carbon double bond which comprise 2 to 10 carbon atoms in the longest chain; vinylaromatic monomers; α,β-ethylenically unsaturated nitrites; α,β-ethylenically unsaturated amides; vinyl ether; or N-vinylpyrrolidone.  
     
     
         46 . A process according to  claim 29 , wherein the polymer has a weight-average molar mass of between 2 000 and 5×10 5  g/mol.  
     
     
         47 . A process according to  claim 29 , wherein the level of copolymer employed during stage c), which is the molar ratio of the complexing group of the copolymer of the anionic hydrophilic part or parts to the number of mole of the copper cation present in the precursor, is between 0.05 and 2.  
     
     
         48 . A process according to  claim 29 , wherein of at least 80% of the particles obtained at the end of stage d) have a mean size between 2 and 500 nm.  
     
     
         49 . A process according to  claim 29 , wherein, after stage d), a stage e) of maturing is further carried out at a temperature of between 10° C. and a temperature of less than or equal to the boiling point of said dispersion.  
     
     
         50 . A process according to  claim 49 , wherein, after stage d) or after stage e), a stage f) a concentration of the dispersion is carried out.  
     
     
         51 . A process according to  claim 50 , wherein the concentration is carried out by partially or completely separating the particles from the medium of the dispersion and then optionally by redispersing the particles thus obtained in an appropriate amount of aqueous medium.  
     
     
         52 . A process according to  claim 51 , wherein the separation stage is carried out is by ultrafiltration, dialysis, precipitation, centrifugation, ultracentrifligation, complete or partial evaporation, with or without heating, of the aqueous medium of the dispersion.