摘要 |
<p>Aqueous suspension of mineral materials contains copolymer as dispersion agent and/or to help crush the materials. The copolymer consists of: (a) at least one ethylenically unsaturated monomer with carboxylic group selected from monoacids e.g. (meth)acrylic, (iso)crotonic, and cinnamic; diacids e.g. fumaric and maleic; acid anhydrides such as maleic anhydride; and diacid hemiesters such as 1-4c monesters of maleic acid; (b) optionally at least one unsaturated monomer with a sulphonic group e.g. sodium methallylsulphonate or styrene sulphonic acid; or a phosphoric group e.g. propylene glycol (meth)acrylate phosphate; (c) optionally at least one unsaturated monomer without a carboxylic group e.g. (meth)acrylic esters, (meth)acrylonitrile, styrene, (meth)acrylamide; and (d) at least one unsaturated oxyalkyl monomer with terminal hydrophobic chain of general formula R-Ä-((CH2-CH(R1)-O)m-CH2-CH2-O)n-CH2-CH(R2)pÜq< /SB>-R'. In the formula, m, n, p≤100; q is number such that 0≤q x (n + m + p)≤100; R1, R2 = H, methyl, or ethyl; R = polymerisable unsaturated radical belonging to group of esters including (meth)acrylic, crotonic and vinylphthalic, as well as unsaturated urethanes such as (meth)acrylurethane, or allylurethane; and R' = hydrophobic radical such as tristyrylphenyl,, or 8-30C alkyl, aryl, alkylaryl, arylalkyl, or, when R = urethane, 8C dialkyl, or, better, when R = unsaturated polymerisable radical,≥22C dialkyl amine; total of a + b + c + d = 100 pts. The suspension has specific viscosity no greater than 25. Also claimed are use of the suspension in paper industry, in particular as size for paper.</p> |