The Dow Chemical Company

James L Brewbaker

William B Marshall

Michael N Mang

Rodrique L Marzett

William A Sprenger

Ray E Drumright

Daniel J Murray

Muthiah N Inbasekaran

Mark S Delaney

James R Pribish

A process for preparing a polyester which includes the step of heating a reaction mixture comprising (i) diesters of dihydric phenols and C.sub.1-10 aliphatic monoacids, (ii) aromatic dicarboxylic acids, and (iii) a catalytic amount of an organic cation-containing salt at a temperature above the melt temperature of the diesters, under reaction conditions sufficient to form the corresponding polyester. Use of this process subjects the polymers prepared thereby to a thermal history which causes relatively little deterioration of the polymer's properties.

Melt polymerization process for preparing aromatic polyesters

Polyetherimides, polyesterimides, poly(ester etherimides) and poly(carbonate imides) which are thermoplastic, polymeric materials contain divalent bisimides of formula ##STR1## wherein R is independently in each occurrence hydrogen, alkyl of from 1 to 20 carbons, aryl or aralkyl of from 1 to 20 carbons, halogen or NO.sub.2. Novel monomeric bisimides corresponding to the above formula are also disclosed.

Fluorene based bisimides and thermoplastic polymers thereof

The invention relates to a class of copolymers capable of forming an optically anisotropic melt comprising recurring structural units (a) independently each occurrence selected from the group consisting of Formula I; recurring structural units (b) independently each occurrence selected from the group consisting of Formulas II and III; and optionally recurring structural units (c) independently each occurrence selected from the group consisting of Formula IV: ##STR1## wherein R independently each occurrence is a chemically inert substituent.

Liquid crystalline copolyesters of 4-hydroxybenzoic acid and substituted

Aliphatic polyesters of 3,4'-biphenyldicarboxylic acid and optionally 4,4'-biphenyldicarboxylic acid are prepared by contacting at least one aliphatic diol having from 2 to 12 carbon atoms with a lower alkyl diester or phenolic diester of 3,4'-biphenyldicarboxylic acid and, optionally, a lower alkyl diester or phenolic diester of 4,4'-biphenyldicarboxylic acid, in the presence of a catalyst at about 180.degree. to about 300.degree. C. These polyesters are suitable for use in making fibers, films, three dimensional molded articles, barrier containers and coatings.

Thermoplastic polyesters containing biphenylene linkages

The invention relates to a class of copolymers capable of forming an optically anisotropic melt comprising recurring structural units (a) independently each occurrence selected from the group consisting of Formula I; recurring structural units (b) independently each occurrence selected from the group consisting of Formulas II and III; recurring structural units (c) independently each occurrence selected from the group consisting of Formula IV and optionally recurring structural units (d) independently each occurrence selected from the group consisting of Formula V: ##STR1## wherein R independently each occurrence is a chemically inert substituent.

Melt processable thermotropic aromatic copolyesters

The invention relates to a class of polyesters and copolyesters which display optical anisotropy in the molten state and to the shaped articles, fibers and films obtained from the optically anisotropic melts. The copolyesters consisting essentially of recurring structural units (a) independently each occurrence selected from the group consisting essentially of Formula I; recurring structural units (b) independently each occurrence selected from the group consisting of Formulas II and III; recurring structural units (c) independently each occurrence selected from the group consisting of Formula IV and optionally recurring structural units (d) independently each occurrence selected from the group consisting of Formula V: ##STR1## wherein R independently each occurrence is selected from the group consisting of hydrogen, halo, lower alkyl, methoxy and phenyl; R' independently each occurrence is selected from the group consisting of hydrogen, halo, methoxy and phenyl; and R' comprises lower alkyl.

Thermotropic copolymers of 4,4'-biphenyldicarboxylic acid

The invention relates to a class of copolyesters which display optical anisotropy in the molten state and to the shaped articles, fibers and films obtained from the optically anisotropic melts. The copolyesters comprise recurring structural units (a) independently each occurrence selected from the group consisting of Formulas I and II; recurring structural units (b) independently each occurrence selected from the group consisting of Formulas III and V; recurring structural units (c) independently each occurrence selected from the group consisting of Formula IV; and optionally recurring structural units (d) independently each occurrence selected from the group consisting of Formula VI: ##STR1## wherein R independently each occurrence is a chemically inert substituent.

The invention relates to a class of copolyesters which display optical anisotropy in the molten state and to the shaped articles, fibers and films obtained from the optically anisotropic melts. the copolyesters comprise recurring structural units (a) independently each occurrence selected from the group consisting of Formulas I and II; and recurring structural units (b) independently each occurrence selected from the group consisting of Formula III; ##STR1## wherein R independently each occurrence is a chemically inert substituent.

Melt processable thermotropic aromatic copolyester derived from hydroxy

A complex of an alkyllithium compound and 1,2-dipyrrolidinoethane is useful as an initiator for the polymerization of ethylene and ethylene block copolymers.

Initiator and method for polymerizing ethylene and preparing block

Curable vinyl ester resin compositions, that can be B-staged with magnesium oxide, comprise a vinyl ester resin having no free carboxyl groups, a reactive diluent, and a thickening agent which is the reaction product of a polyethylene glycol having a molecular weight greater than 2,000 and an anhydride of a polycarboxylic acid with the thickening agent having more than two carboxyl groups per molecule.

Thickened vinyl ester resin compositions

The shrinkage of a thermosettable composition comprising an unsaturated polyester and a vinyl monomer capable of cross-linking the polyester is reduced during cure by the addition to the composition of an alkylene oxide polymer which is soluble in the thermosettable composition but which is substantially less soluble in the cured thermoset composition.

Low profile additives for unsaturated polyester resins

Halopolymers, such as chlorinated polyethylene, are uniquely vulcanized by heating a curable mixture including the halopolymer and a 1,3-diaminopropane or salt thereof. A preferred mixture further includes an acid acceptor, such as calcium oxide or calcium hydroxide, and sulfur or a sulfur-containing compound.

Halopolymers crosslinked with a 1,3-diaminopropane

Low shrink and low profile reinforced plastic systems are prepared from vinyl ester resins by incorporating therein an additive having the formula: ##STR1## WHEREIN R.sub.1 and R.sub.2 are hydrogen, methyl or ethyl with the provision that, if either R.sub.1 or R.sub.2 is hydrogen, the other is methyl or ethyl, n and m are whole numbers such that said additive is soluble in said resin when uncured and insoluble in said resin when cured; and B is the residue of a hydroxyl containing initiating compound. Typical of such compounds are water, ethylene glycol, glycerine and phenol. The value of p is equal to or less than the number of hydroxyls in the initiating compound.

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Midland, MI, United States of America

James L Brewbaker