Abstract: Sizes for paper are based on finely divided aqueous dispersions of copolymers which are obtainable by copolymerization of from 10 to 56 parts by weight of a monomer mixture of(a) from 20 to 65% by weight of (meth)acrylonitrile,(b) from 35 to 80% by weight of one or more acrylates of monohydric, saturated C.sub.3 -C.sub.8 -alcohols and(c) from 0 to 10% by weight of other ethylenically unsaturated copolymerizable monomers by an emulsion polymerization method in 100 parts by weight of an aqueous solution of from 1.7 to 25% by weight of a degraded starch having a viscosity .eta..sub.i of from 0.12 to 0.50 dl/g, at from 40.degree. to 100.degree. C. in the presence of a peroxide-containing initiator.

Abstract: Sizing agents for paper are based on finely divided aqueous dispersions of copolymers obtainable by copolymerizing from 40 to 140 parts by weight of a monomer mixture of(a) from 20 to 65% by weight of (meth)acrylonitrile,(b) from 35 to 80% by weight of one or more acrylates of monohydric saturated C.sub.3 -C.sub.8 -alcohols and(c) from 0 to 10% by weight of other ethylenically unsaturated copolymerizable monomers,the weight percentages (a), (b) and (c) always adding up to 100, in the manner of an emulsion polymerization in 100 parts by weight of an aqueous solution containing in solution from 2.7 to 15% by weight of a degraded starch having a viscosity n.sub.i from 0.04 to less than 0.12 dl/g at from 40.degree. to 100.degree. C. in the presence of a peroxide initiator.

Abstract: A paper size comprising a water-soluble salt of a copolymer of from 30 to 85% by weight of olefins of 2 to 12 carbon atoms, having a terminal double bond, and/or vinyl ethers, and from 15 to 70% by weight of basic acrylic and/or methacrylic compounds, which copolymer has a molecular weight of from 600 to 4,500 and is manufactured by continuous copolymerization at from 130.degree. to 320.degree. C.

Abstract: Shear-resistant aqueous copolymer emulsions which can be used for sizing paper are manufactured by first copolymerizing, in the aqueous phase of an aqueous emulsion, using conventional polymerization initiators which form free radicals, (A) from 0.5 to 15 per cent by weight of monomers containing a polymerizable C.dbd.C bond and at least one carboxyl and/or sulfonic acid or phosphate or phosphite group with (B) from 5 to 30 per cent by weight of monomers containing a C.dbd.C bond and a tertiary or quaternary amino group, or a nitrogen-containing heterocyclic group, and then adding, while continuing the copolymerization, (C) from 0 to 94.5 per cent by weight of styrene and/or acrylonitrile and (D) from 0 to 94.

Abstract: Process for the manufacture of surface-sized papers by impregnating a paper with a solution containing a water-soluble salt of a random polymer based on .alpha.-olefins and ethylenically unsaturated acids and a compound of the formula: ##EQU1## wherein R is alkyl, aryl or a radical of the formula: ##EQU2## and R.sup.1 and R.sup.2 each independently denotes H, R or a radical of the formula:R -- O-- CH.sub.2 --and drying the impregnated paper. Very well sized papers are obtained which show alkali resistance and filler compatibility.