Nippon Oil Fats Co., Ltd.

Other

Seiko Epson Corporation

Idemitsu Kosan Company, Limited

Tosoh Corporation

Mitsubishi Petrochemical Company Limited

Hirosuke Kojima

Takayuki Otsu

Yoshishige Murata

Naoyuki Amaya

Toru Doi

Satoshi Kubota

Mikio Takagi

Yasumi Koinuma

Shunichi Himori

Takashi Kiriyama

Tomohiro Ishikawa

Hiroshi Kawashima

Keizo Anan

Akira Yamada

Masaru Egawa

Kiyotaka Shigehara

Kiyoshi Endo

Kazuichi Tsuda

Norihiro Kaiya

Masafumi Nisimura

Akikazu Matsumoto

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.

ABA type block copolymers

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.

Ultrathin membrane of polymethacrylate or polycrotonate and device

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).

Separation membrane

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.

Novel block copolymer of styrene and ethylene

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.3 represents an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms or a cycloalkyl group having 3 to 12 carbon atoms; and a radical polymerizable vinyl monomer.

Contact lens article made of silicon- and fluorine-containing resin

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.

Optical resin from diallyl esters

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.

Method for modifying polyfumaric acid diester

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.

Method of preparing a low density, nonflammable polyvinyl foam

Growing community of inventors

Nara, Japan

Takayuki Otsu