Abstract: An acrylate is polymerized by the photo-decomposition of ##STR1## to make a polymeric intermediate containing dithiocarbamate groups at both its ends, and a hard polymer-forming monomer is polymerized by the photo-decomposition of this dithiocarbamate group-containing polymeric intermediate to form blocks of a polymer of said hard polymer-forming monomer on both sides of said polymeric intermediate, thereby forming an ABA type block copolymer.

Abstract: An ultrathin polymeric membrane has a membrane thickness of 10 to 1,000 .ANG.. The membrane is constituted of polycarboxylate and obtained by the spin coating method or by the Langmuir-Blodgett method. The polycarboxylate contains recurrent units represented by the formula (I) ##STR1## wherein R.sub.1 and R.sub.2 represent different groups and each stands for a methyl group or a hydrogen atom, and R represents a hydrocarbon group selected from the group consisting of a branched alkyl group having 3 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, a substituted alkyl group having 2 to 6 carbon atoms, a substituted cycloalkyl group having 3 to 10 carbon atoms and a siloxanic hydrocarbon group.

Abstract: A separation membrane comprising a resin being constituted of the repeating unit represented by the general formula (I) and having a number average molecular weight of not less than 1.times.10.sup.3 in polystyrene equivalent: ##STR1## wherein R.sub.1 denotes an alkyl group of 1-20 carbons, a fluoroalkyl group of 1-20 carbons, or a group represented by the general formula: --(--X--).sub.m --(SiR.sub.2 R.sub.3 --).sub.n --R.sub.4, or --(--X--).sub.m --(--SiR.sub.2 R.sub.3 O--).sub.n --SiR.sub.4 R.sub.5 R.sub.6 (wherein X is an alkylene group of 1-8 carbons or a phenylene group of 6-12 carbons; m is 0 or 1; n is an integer of 1-20; R.sub.2, R.sub.3, R.sub.4, R.sub.5, and R.sub.6 are respectively a group, having 1-8 carbons, selected from an alkyl group, a cycloalkyl group, a phenyl group, an alkoxyl group, and a fluoroalkyl group, and may be the same with or different from each other).

Abstract: A novel method is proposed for the preparation of a block copolymer of styrene and ethylene having a very narrow molecular weight distribution and controlled molar ratio of the styrene moiety to ethylene moiety in a high efficiency. The method comprises the steps of: (a) living-polymerizing styrene by using an organic lithium compound as a polymerization initiator; (b) admixing the polymerization mixture containing the living polymer of styrene with a tertiary diamine compound, such as N,N,N',N'-tetramethyl ethylene diamine; and (c) introducing ethylene monomer into the polymerization mixture to effect polymerization of ethylene on to the living polymer molecules of polystyrene.

Abstract: A contact lens article comprises a resin obtained by copolymerizing starting monomer components containing a silicon-containing compound (A) represented by the formula ##STR1## wherein R.sub.1 represents a hydrogen atom or a methyl group, X.sub.1 and X.sub.2 each represent a methyl group or ##STR2## l represents 0 or 1, m represents an integer of 1 to 3 and n and p each represent an integer of 0 to 3; a fluorine-containing compound (B) represented by the formula (II) of: ##STR3## wherein at least one of R.sub.2 and R.sub.3 represents a straight chain or branched chain fluoroalkyl group represented by --C.sub.h H.sub.k F.sub.2h+l-k in which h represents an integer of 2 to 18, k represents an integer of 1 to 2 multiplied by h and when one of R.sub.2 and R.sub.3 is --C.sub.h H.sub.k F.sub.2h+l-k, the other of R.sub.2 and R.sub.

Abstract: According to the invention, there are provided an optical resin and a process for preparing such a resin. The optical resin is obtained by polymerizing a feed monomer comprising at least a diester of dicarboxylic acid represented by the general formula (1) of: ##STR1## wherein R.sub.1 and R.sub.2 each represent the same or different groups and stand for an alkyl or alkenyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms or an ester residue having at least one aromatic ring.

Abstract: According to the invention, a method for modifying a polyfumaric acid diester is provided. The method comprises subjecting the polyfumaric acid diester to thermal treatment to thereby obtain a polyfumarate having carboxyl groups. The polyfumaric acid diester is obtained by polymerizing a fumaric acid diester represented by the following general formula of: ##STR1## wherein R represents an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms or an organic residue having at least one aromatic ring.

Abstract: A method of preparing a foamable polyvinyl system resin composition which renders a non-flammable, high strength to weight ratio foam product comprises, reacting at least 0.05 parts by weight of an organic radical initiator per 1 part by weight of polyvinyl system resin with the components consisting essentially of (a) at least one polyvinyl system resin (b) 2-100 parts by weight of at least one inorganic filler per 1 part by weight of polyvinyl system resin (c) an effective amount of at least one blowing agent.