Allied Corporation

Alliedsignal Inc.

Tse C Wu

Dusan C Prevorsek

David H Wertz

Leon Segal

James C West

This invention relates to a process for the production of poly(vinyl alcohol) having a weight average molecular weight of at least about 0.4.times.10.sup.6 by polymerizing vinyl acetate at a temperature of from about 0.degree. C. to about 40.degree. C. in the presence of an azo free radical polymerization initiator essentially in the absence of ultraviolet radiation to form an essentially linear poly(vinyl acetate) having a weight average molecular weight of at least about 1.0.times.10.sup.6 and thereafter hydrolyzing the poly(vinyl acetate) to form the desired poly(vinyl alcohol).

Process for the production of poly(vinyl acetate) and poly(vinyl alcohol)

An improved poly(vinyl acetate) which on hydrolysis and reacetylation has an intrinsic viscosity of at least about 5 dL/g and an improved poly(vinyl alcohol) which on acetylation yields poly(vinyl acetate) having an intrinsic viscosity of at least about 5 dL/g. Such poly(vinyl acetate) can be prepared by photo-initiated free radical bulk polymerization of vinyl acetate with controlled low initiator concentration, polymerization temperature and reaction time. Such poly(vinyl alcohol) can be prepared by conventional alcoholysis of the poly(vinyl acetate).

High molecular weight poly(vinyl acetate) and poly(vinyl alcohol) and

Purified aromatic dicyanates are cured with a catalyst which is an Mn(II), Ag(II), Fe(III), Bi(III), In(III) or Hf(IV) salt at 150.degree.-200.degree. C. and then at 200.degree.-300.degree. C. for a time sufficient to cure the dicyanate without causing color formations to the extent of a Yellowness Index over 30. In some forms the dicyanate is combined with the catalyst and a thermoplastic.

Low color compositions comprising a cross-linked polycyanurate polymer

An interfacial process for producing a poly(ester-carbonate) containing aromatic dihydroxy moieties derived from phenolphthalein. In the process, phenolphthalein polyester oligomers are formed first, and then the oligomers are reacted with phosgene and with additional aromatic or cycloaliphatic diacyl halide and with an aqueous solution of bisphenol-derived salt to form the poly(ester-carbonate).

Interfacial process for producing poly(ester-carbonate) containing

A monomeric aromatic dicyanate is purified to remove color forming impurities, combined with a zinc salt catalyst and cured first below 200.degree. C. and then for a limited time at or above 200.degree. C., either alone or in admixture with or on a thermoplastic polymer. For example, purified 2,2-bis(4-cyanatophenyl)propane is purified, combined with a poly(ester carbonate) and zinc chloride, and then cured at increasing temperatures from 150.degree. C. to 250.degree. C.

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Morristown, NJ, United States of America

Tse C Wu