Aqueous resin composition and method of producing the same
An aqueous resin composition that can provide excellent properties using a high molecular weight resin and less amount of surfactant, and also that does not require a complicated production procedure, is provided. The aqueous resin composition is obtained by heating and dissolving 100 parts by mass of acid-modified chlorinated polyolefin with an average molecular weight of 37,000 to 150,000 in the presence of 2 to 30 parts by weight of a surfactant, 10 to 50 parts by mass of a glycol ether-based compound that satisfies general formula (1) shown below, and 150 to 425 parts by mass of water, and then dispersing this with a basic compound that has been added at a ratio of 1 to 4 chemical equivalents per carboxyl group of the acid-modified chlorinated polyolefin. General Formula (1) C 4 H 9 —(OCH 2 CH 2 ) n —OH n: an integer from 1 to 4.
1. A method of producing an aqueous resin composition, comprising:
a first step of mixing
(a) 100 parts by mass of acid-modified chlorinated polyolefin with a weight-average molecular weight of 37,000 to 150,000,
(b) 2 to 30 parts by mass of a surfactant,
(c) 10 to 50 parts by mass of a glycol ether-based compound that satisfies C 4 H 9 —(OCH 2 CH 2 ) n —OH (Formula (1)) wherein n is an integer from 1 to 4, and
(d) 150 to 425 parts by mass of water
to obtain a mixture;
a second step of heating the mixture;
a third step of adding (e) a basic compound to the mixture obtained by the second step at a ratio of 1 to 4 chemical equivalents per carboxyl group of the acid-modified chlorinated polyolefin;
and a fourth step of mixing the mixture obtained by the third step;
wherein (e) the basic compound is at least one member selected from the group consisting of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, ammonium carbonate, triethylamine, N,N-dimethylethanolamine, aminoethanolamine, N-methyl-N,N-diethanolamine, isopropylamine, iminobispropylamine, ethylamine, diethylamine, 3-ethoxypropylamine, 3-diethylaminopropylamine, sec-butylamine, propylamine, methylaminopropylamine, methyliminobispropylamine, 3-methoxypropylamine, monoethanolamine, diethanolamine, triethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine, 2-amino-2-methyl-1-propanol, 2-dimethylamino-2-methyl-1-propanol, and ammonia.
2. The method of claim 1 , wherein the acid-modified chlorinated polyolefin is produced by
(i) obtaining an acid-modified polyolefin by graft-copolymerizing at least one species selected from the group consisting of α,β-unsaturated carboxylic acids and anhydrides thereof in an amount of 0.6 to 10 mass % with at least one species selected from the group consisting of polypropylene and a propylene-α-olefin copolymer, and
(ii) chlorinating the acid-modified polyolefin.
3. The method of claim 1 , wherein the chlorine content of the acid-modified chlorinated polyolefin is 10 to 35 mass %.