摘要:
A process for making an aqueous vinyl acetate/ethylene/N-methylolacrylamide copolymer emulsion comprising:(a) adding an initial charge containing all the vinyl acetate monomer to be polymerized and an effective amount of an emulsifying system consisting essentially of an anionic surfactant, especially a salt of an alkylphenoxy poly(ethyleneoxy) sulfate containing about 3-5 ethyleneoxy units,(b) pressurizing the reactor with sufficient ethylene to yield a copolymer having the desired Tg,(c) initiating polymerization at a temperature from 45.degree. to 85.degree. C., and(d) continuing polymerization at a temperature from 45.degree. to 85.degree. C., while continuously adding N-methylolacrylamide over a period of time such that the free vinyl acetate monomer content of the reaction medium is about 2-4% upon completion of the N-methylolacrylamide addition.
摘要:
An emulsion composition is disclosed which provides a binder having good wet tensile strength and low heat seal temperature for nonwoven products which comprises an aqueous dispersion of a mixture consisting essentially of 50 to 95 wt % of a vinyl acetate-ethylene copolymer and 5 to 50 wt % of a vinyl acetate-ethylene-crosslinking monomer copolymer.
摘要:
Vinyl chloride-propylene copolymer resin having improved porosity as shown by an increased irreversible plasticizer take-up is produced by the suspension polymerization of vinyl chloride and propylene in the presence of a binary suspension system of a hydroxypropylmethyl cellulose having 19-30% methoxyl and 4-12% hydroxypropoxyl substitution and a 30-50 mole % hydrolyzed polyvinyl alcohol.