摘要 |
Aqueous suspensions of purified minerals (A) contain a milling aid comprising a copolymer (B), having intrinsic viscosity 100 ml/g or less, obtained from: (a) ethylenically unsaturated anionic monomer(s) with an acid function; (b) non-ionic ethylenic monomer(s) (I) on which at least one alkoxy- or hydroxy-polyalkylene glycol function is grafted; (c) organosilicon or organofluorine monomer(s); and (d) optionally (meth)acrylamide type, water-insoluble, cationic or quaternary ammonium and/or crosslinking monomer(s). Aqueous suspensions of purified minerals (A) contain a milling aid comprising a copolymer (B), having an intrinsic viscosity of 100 ml/g or less, obtained from: (1) at least one ethylenically unsaturated anionic monomer with a monocarboxylic acid function (e.g. (meth)acrylic acid or a diacid monoester such as a mono-(1-4C) ester of maleic or itaconic acid), dicarboxylic acid function (e.g. crotonic, isocrotonic, cinnamic, itaconic or maleic acid, or a corresponding anhydride such as maleic anhydride), a sulfonic acid function (e.g. acrylamido-methyl-propane-sulfonic acid, sodium methallylsulfonate, vinyl-sulfonic acid or styrene-sulfonic acid), a phosphoric acid function (e.g. vinylphosphoric acid, ethylene glycol methacrylate phosphate, propylene glycol acrylate phosphate or their ethoxylates) or a phosphonic acid function (e.g. vinylphosphonic acid); (2) at least one non-ionic unsaturated monomer of formula (I); (3) at least one organosilicon or organofluorine monomer, preferably a silicon-containing monomer of formula (IIa), R-A-Si(OB)3 (IIb) or (IIc); (4) optionally one or more of (a) monomers of the (meth)acrylamide (or derivative) type, (e.g. N-(3-(dimethylamino)-propyl)-(meth)acrylamide), (b) water-insoluble monomers such as alkyl (meth)acrylates, unsaturated esters (e.g. N-(2-dimethylamino)-ethyl)-(meth)acrylate) or vinyl compounds (e.g. vinyl acetate, vinyl pyrrolidone, styrene, alpha-methyl-styrene or their derivatives) or (c) cationic or quaternary ammonium monomers such as (2-((meth)acryloyloxy)-ethyl)-trimethylammonium, (3-((meth)acrylamido)-propyl)-trimethylammonium or dimethyl diallylammonium chloride or sulfate; and (5) optionally one or more crosslinking monomer selected from ethylene glycol dimethacrylate, trimethylol propane triacrylate, allyl acrylate, allyl maleate, methylene-bis-(meth)acrylamide, tetraallyloxy-ethane or allyl ethers of polyols (e.g. pentaerythritol, sorbitol or sucrose). (Structures (I), page 85, (IIa), page 87, and (IIc), page 88) m, p, n, = up to 150; q = integer such that (m + n + p)/q = 5-150 (preferably 15-120); R1, R2 = H, Me or Et; R = radical containing a polymerizable unsaturated selected from vinyl, (meth)acrylic, maleic, itaconic, crotonic or vinylphthalic acid ester, unsaturated urethane (e.g. (meth)acrylurethane, alpha,alpha'-dimethyl-isopropenyl-benzyl urethane or allyl urethane), optionally substituted allyl or vinyl ether or ethylenically unsaturated amide or imide; R' = H or 1-40C hydrocarbyl (preferably 1-12C (especially 1-4C) hydrocarbyl); m1 - m4, p1 - p4, n1 - n4 = up to 150; q1 - q4 = integers such that (m1 + n1 + p1)/q1, (m2 + n2 + p2)/q2, (m3 + n3 + p3)/q3 and (m4 + n4 + p4)/q4 = 0-150; r, r' = 1-200; R3, R13 = as for R; R4, R5, R10, R11, R14, R15, R20, R21 = H, Me or Et; R6 - R9, R16 - R19 = alkyl, aryl, aralkyl or alkaryl of 1-20C; R12 = 1-40C hydrocarbyl; A, B, D, E = direct bond or 1-4C, hydrocarbyl, provided that B is not a direct bond in (IIb). Independent claims are included for: (a) agents for aiding the milling of (A) in aqueous suspension, comprising the copolymers (B); and (b) a milling process for obtaining suspensions of very fine particles of (A), including the addition of 0.05-10 wt. % (as solids based on (A)) of (B) before and/or during the miling stage, optionally in combination with other dispersants or milling aids. |