Japan Exlan Company Limited

Sumitomo Chemical Company, Limited

Toyo Boseki Kabushiki Kaisha

Toshiyuki Kobashi

Hideo Naka

Seiji Takao

Masahiko Ozaki

Hiroaki Sugimoto

Noboru Abe

Shoyo Takagi

Kazuo Hayatsu

Hirotaka Shiota

Masaaki Fujimatsu

Kenichi Ono

Jinya Takeuchi

Kenichi Masuhara

Shojiro Ito

Haruki Umetani

Jun Takagi

Yasuhiro Kitagawa

Katsumi Kunikata

A stannic acid anhydride represented by the structural formula shown below. When said compound as it is, or the same coated on a substrate or impregnated into it, is baked, it is possible to finally form tin oxide which has excellent transparency and conductivity, ##STR1## wherein X represents ##STR2##

Stannic acid anhydride

By reacting a tin carboxylate with hydrogen peroxide at a particular ratio in an aqueous medium, this invention provides a transparent aqueous tin compound solution which can finally form, in an industrially advantageous manner, tin oxide having excellent transparency, uniformity, compactness, conductivity, etc.

Transparent aqueous tin compound solution

Aromatic polyester fibers having high strength and high modulus of elasticity can be obtained stably for a long period of time by melt spinning by using a screw type extruder having a screw which has a compression ratio of 2.5 to 4.0 and thereby inhibiting entrapment in the resultant molten polyester of gases present in or on prowders, granules or pellets being melted, and by back pressure of the molten polyester sending gas generated by decomposition of the molten polyester to a back portion of the extruder, and then extruding and melt spinning the molten polyester at a temperature of 280.degree. C. to 420.degree. C.

Process for melt spinning aromatic polyester

In a process for producing an aromatic polyester fiber by heat-treating a fiber obtained by melt-spinning an aromatic polyester exhibiting anisotropy in its molten state, an aromatic polyester fiber having high strength and high modulus of elasticity can be produced with suppressed fusion between single filaments during the heat treatment by (a) subjecting the fiber obtained by melt spinning to heat treatment in an organic liquid heating medium or (b) adhering to the fiber obtained by melt spinning at least one member selected from the group consisting of suspensions having a concentration of 0.05 to 20% by weight of organic polymer powders having a melting point or a softening temperature higher than the heat treatment temperature, and suspensions having a concentration of 0.1 to 20% by weight of barium sulfate powder or barium titanate powder, and then subjecting the resulting fiber to heat treatment.

Process for producing aromatic polyester fiber

A bead-like glycidyl (meth)acrylate polymer is produced by aqueous suspension polymerization of glycidyl (meth)acrylate alone or a monomer mixture composed of more than 50 weight % of said monomer and at least one other monomer which forms the remainder, in the presence of a specific aqueous polymer, at a pH of from 2 to 9 and at a stirring speed of from 50 to 500 r.p.m. By heat treating said bead-like polymer at a pH below 3 and at a temperature above 70.degree. C., hydroxyl groups resulting from the ring opening of the epoxy groups are introduced, whereby a solvent-insoluble bead-like polymer having a gel water content not less than 30% is produced.

Bead-like polymer and production thereof

This invention provides an aqueous antimony oxide sol composed of Sb.sub.6 O.sub.13, 1 to 100 m.mu. in particle diameter, dispersed in an aqueous medium or composed of said Sb.sub.6 O.sub.13 treated with a particular quantity of a particular organic silicon compound and regulated to within a prescribed pH range, which has a high concentration and a small quantity of impurities, and moreover has excellent thermal stability and chemical stability.

Chemically stable aqueous antimony oxide sol

An aromatic polyester showing anisotropy in the molten state is melt spun stably for a long period of time by controlling an extrusion pressure at a nozzle portion to 3 kg/cm.sup.2 G or higher and an atmospheric temperature T.sub.N at a nozzle outlet to a degree satisfying the following formula: (T.sub.F -100).ltoreq.T.sub.N .ltoreq.T.sub.F, wherein T.sub.F is a flowing temperature of the aromatic polyester, and preferably controlling the pressure of a polymer melt at a tip outlet of an extruder to 15 kg/cm.sup.2 G or higher, whereby a highly orientated fiber of fine denier is obtained.

Melt spinning process of aromatic polyester

The present invention provides a gel having excellent separation ability, operability and a long life, for separating useful components from a rhodanate-containing detoxication treated liquid. The gel consists of a cross-linked polymer with more than 50 weight % of repeating units which are composed of 2,3-dioxypropyl (meth)acrylate or 2,3-dioxypropyl (meth)allyl ether, and whose average particle diameter is more than 10.mu. and gel water content is from 30 to 150%. The present invention also provides a method of separation using said gel.

Gel for the separation of useful components contained in

Hard polyvinyl alcohol gel is produced by copolymerizing a carboxylic acid vinyl ester monomer with a particular cross-linking agent and then saponifying the copolymer. This hard polyvinyl alcohol gel has excellent mechanical strength and separation ability and has no problem in copolymerizability and polymerization speed. Moreover, it shows no change in cross-linked structure before and after saponification.

Method of producing hard polyvinyl alcohol gel

This invention relates to a method of producing a flame-retardant acrylic polymer by polymerizing, in the presence of a radical polymerization initiator, a vinyl monomer containing acrylonitrile in an amount of more than 75 weight %, in an aqueous medium in which is present a halogen-containing polymer latex substantially free from an emulsifier. The acrylic polymer can provide flame-retardant shaped products, especially fibers, which have no problems in the operation of spinning, transparency, gloss, dyed color clearness, etc.

Method of producing a flame-retardant acrylic copolymer

The present invention provides chemically stable colloidal antimony oxide which has been treated with a particular organosilicon compound in the ratio of from 0.5 to 25 weight % based on the antimony and whose pH has been regulated to within the range of from 2 to 12.

Chemically stable colloidal antimony oxide

Polyacrylonitrile (PAN) fiber of high strength (tensile strength.gtoreq.20 g/d) produced from a polymer composed mainly of acrylonitrile (AN) and having a weight average molecular weight not less than 400,000, and a method of producing said fiber characterized by a multistage stretching step and a drying step under particular conditions.

Method for the production of high strength polyacrylonitrile fiber

The invention provides a polyacrylonitrile fiber having a tensile strength above 13 g/d and a modulus of elasticity above 2.4.times.10.sup.11 dyne/cm.sup.2, which is useful for tire cords, fiber-reinforced composite materials, precursors for producing carbon fiber, etc. The fiber is produced by integrally combining technical means which comprise using a polymer composed mainly of acrylonitrile whose weight average molecular weight is more than 400,000 and Mw/Mn ratio is less than 7.0; preparing a spinning solution from the polymer; spinning the solution into filaments; subjecting the resulting filaments to multistage stretching; and drying the filaments, all these steps being conducted under particular conditions.

Polyacrylonitrile fiber with high strength and high modulus of elasticity

Method of producing a flame-retardant acrylic polymer

The present invention relates to a process for producing a packing material for use in liquid chromatography which comprises aqueous suspension polymerizing vinyl acetate, a (meth)acrylic acid ester or a glycidyl monovinyl ester or ether with a monomer mixture composed mainly of a cross-linking monomer in the presence of a diluent selected from among epichlorohydrin and glycidyl ethers and thereafter removing it from the resulting polymer particles by ring-opening the epoxy groups in said diluent. This process provides a packing material for use in liquid chromatography which is uniform and porous and moreover is excellent in mechanical strength.

Growing community of inventors

Okayama, Japan

Toshiyuki Kobashi