Abstract: A process for isolating or recovering a polymer in the form of particles or powder from a solution thereof which comprises admixing a solution of the polymer in a substantially water-immiscible organic solvent with an aqueous solution of a water-soluble polymeric dispersing agent, and distilling away the organic solvent from the mixture in the form of a dispersion.

Abstract: An aromatic polyester having improved heat resistance, hydrolysis resistance and alkali resistance which comprises recurring units of the general formula: ##STR1## and recurring units of the general formula: ##STR2## wherein R.sup.1 and R.sup.2 are an alkyl or alkoxyl group having 1 to 4 carbon atoms, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are the same or different and each is an alkyl or alkoxyl group having 1 to 4 carbon atoms, Cl or Br, x and y are an integer of 1 to 4, z, x', y' and z' are 0 or an integer of 1 to 4, and X is an alkylidene or cycloalkylidene group having 1 to 8 carbon atoms, --O--, --S--, --SO.sub.2 -- or --CO--.

Abstract: A polyesteramide having structural units of the general formula: ##STR1## wherein Ar is a bivalent aromatic group comprising at least 10% by mole of a group having the following formula: ##STR2## in which R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are the same or different and each is methyl group or ethyl group, and structural units of the general formula: ##STR3## wherein R is a bivalent organic group. At least 10% by mole of a bifunctional phenol compound to be used is a tetraalkylbisphenol-F, and whereby the obtained polyesteramide has improved hydrolysis resistance and electric characteristic with an excellent heat resistance.

Abstract: A heat resisting aromatic polyester resin comprising (a) recurring units of the formula (I): ##STR1## wherein X is a bivalent group selected from the group consisting of an unsubstituted or substituted bivalent hydrocarbon group having 1 to 10 carbon atoms,--O--, --S--, --SO.sub.2 --and--CO--, and (b) recurring units of the formula (II): ##STR2## wherein X is as defined above, R and R' are a group selected from the group consisting of alkyl, aryl, aralkyl, alkoxyl, aryloxyl and phenylalkoxyl groups having 1 to 20 carbon atoms, their substituted groups, a halogen atom and a mixture thereof, p+q=1 to 8, and m and n are 0 or 1, but n is not 0 when m is 1, provided that up to 10% by mole of the total of the units: ##STR3## in the formulas (I) and (II) may be replaced with units: ##STR4## the ratio of (a)/[(a)+(b)]being from 0.05 to 0.95 by mole. The polyester resin is substantially amorphous and soluble in some organic solvents, and has an excellent heat resistance.

Abstract: A process for manufacturing an aromatic polyester by reacting an aromatic dicarboxylic acid dichloride with an alkali metal salt of a bisphenol comprises adding 0.01 to 100 mol %, based on the total monomer quantity, of an acid halide into the reaction system.

Abstract: A polyether of the general formula: ##STR1## in which Ar stands for a divalent organic group of the aromatic series, R stands for CH.sub.3, CH.sub.3 CH.sub.2, Cl or Br, and n is an integer of 0 to 4. It contains at least 1 mol % of unit `B`. A method of manufacturing such a polyether is also disclosed.