To provide a highly heat resistant flame retardant. A polymer having repeating units represented by the following formula (1), which has a weight average molecular weight as calculated as standard polystyrene of at least 6,000: ##STR00001##
wherein R is a C.sub.1-6 alkylene group, —S— or —SO.sub.2—.

To provide a highly heat resistant flame retardant. A polymer having repeating units represented by the following formula (1), which has a weight average molecular weight as calculated as standard polystyrene of at least 6,000: ##STR00001##
wherein R is a C.sub.1-6 alkylene group, —S— or —SO.sub.2—.

Provided is an epoxy resin composition including an epoxy resin, an epoxy resin curing agent containing an amine-based curing agent, and an acidic compound, wherein a ratio (basic nitrogen/acid groups) of a molar equivalent of basic nitrogen in the epoxy resin composition to a molar equivalent of acid groups derived from the acidic compound is from 0.10 to 3.0. Also provided are a gas barrier film and a laminate in which the epoxy resin composition is used.

Copolymer C comprising polyarylene ether blocks A and polyalkylene oxide blocks PAO, wherein said polyarylene ether blocks A are blocks of at least one partially sulfonated polyarylene ether.

Copolymer C comprising polyarylene ether blocks A and polyalkylene oxide blocks PAO, wherein said polyarylene ether blocks A are blocks of at least one partially sulfonated polyarylene ether.

A polyarylene ether comprising in polymerized form A) at least one tri- or higher functional compound and B) isosorbide, isomannide, isoidide or a mixture thereof, wherein the polyarylene ether is a polyarylene ether sulfone or a polyarylene ether ketone, a process for its preparation and its use in the preparation of a coating, film, fiber, foam, membrane or molded article.

A polyarylene ether comprising in polymerized form A) at least one tri- or higher functional compound and B) isosorbide, isomannide, isoidide or a mixture thereof, wherein the polyarylene ether is a polyarylene ether sulfone or a polyarylene ether ketone, a process for its preparation and its use in the preparation of a coating, film, fiber, foam, membrane or molded article.

A compound having end groups each having a reactive group that are disposed at both ends respectively, and between the end groups, either or both of a first structure in which an aromatic cyclic group, an ether oxygen, a methylene group, an aromatic cyclic group, a methylene group, an ether oxygen and an aromatic cyclic group are bonded together in this order and a second structure in which an aromatic cyclic group, a methylene group, an ether oxygen, an aromatic cyclic group, an ether oxygen, a methylene group and an aromatic cyclic group are bonded together in this order.

A compound having end groups each having a reactive group that are disposed at both ends respectively, and between the end groups, either or both of a first structure in which an aromatic cyclic group, an ether oxygen, a methylene group, an aromatic cyclic group, a methylene group, an ether oxygen and an aromatic cyclic group are bonded together in this order and a second structure in which an aromatic cyclic group, a methylene group, an ether oxygen, an aromatic cyclic group, an ether oxygen, a methylene group and an aromatic cyclic group are bonded together in this order.

An aromatic polysulfone resin produced by the polycondensation of 4,4′-dihydroxydiphenylsulfone represented by chemical formula (S1) shown below and 2-(4-(4-hydroxyphenylsuIfonyl)phenoxy)-5-(4-hydroxyphenylsulfonyl)phenol represented by chemical formula (S2) shown below with 4,4′-dichlorodiphenylsulfone represented by chemical formula (S3) shown below.

##STR00001##

wherein hydrogen atoms in phenylene groups in formula (S1), formula (S2) and formula (S3) may be each independently substituted with an alkyl group, an aryl group or a halogen atom.