The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 29, 1984
Filed:
Jul. 06, 1982
Dale S Gibbs, Midland, MI (US);
Warren L Treptow, Midland, MI (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
A process for preparing, in aqueous emulsion, controlled interpolymer compositions. The interpolymer compositions have polymerized therein from about 86 to 92 mole percent, vinylidene chloride, from about 14 to 8 mole percent of a comonomer mixture of methyl methacrylate and a comonomer selected from the group consisting of acrylonitrile, methacrylic acid and methacrylonitrile in a ratio of the comonomer to methyl methacrylate of from about 0.5:1 to 2:1, and from about 0.5 to 1.0 weight percent itaconic acid, based on weight of vinylidene chloride plus comonomer mixture. The interpolymers are prepared in a three step process. The third step, or Step III, wherein monomer feeding is step-wise reduced for a portion of the step and a polymerization initiator is added at generally the same constant rate as the rate of addition in Steps I and II, generally reduces the amount of unreacted mixed monomers remaining after monomer addition is completed. As such, the detrimental results produced when a large amount of polymer composition variation in the direction of high vinylidene chloride fractions are markedly reduced.