Patents Assigned to Shinetsu Chemical Company
  • Patent number: 4136242
    Abstract: A polymerization vessel equipped with a condenser is charged with vinyl chloride, a suspending agent or dispersing agent, and water. The mixture is subjected to a preparatory stirring in the absence of a catalyst. The polymerization catalyst is added thereto when bubbling caused by the preparatory stirring subsides and stable suspended oil drops form. Blockage of the condenser by polymer scale deposition is substantially reduced. The addition of an alkaline substance, an oxidizing substance or an azine dye further reduces polymer scale deposition. Preferably the operation of the condenser is initiated only after the conversion rate is higher than 5% or the average value per unit hour.
    Type: Grant
    Filed: April 18, 1977
    Date of Patent: January 23, 1979
    Assignee: Shinetsu Chemical Company
    Inventors: Shunichi Koyanagi, Shigenobu Tajima, Kazuhiko Kurimoto, Yoshitaka Kiri
  • Patent number: 4057596
    Abstract: Anti-sticking silicone compositions comprising (a) a diorganopolysiloxane of substantially straight-chain molecular structure having vinyldimethylsilyl terminal groups at both chain ends, (b) a diorganopolysiloxane of substantially straight-chain molecular structure having hydrogendimethylsilyl terminal groups at both chain ends, (c) a methylvinylpolysiloxane having at least three vinyl groups bonded to the silicon atoms in one molecule, (d) a methylhydrogenpolysiloxane having at least three hydrogen atoms bonded directly to the silicon atoms in one molecule, and (e) a catalyst for the addition reaction between the silicon-bonded vinyl groups and the silicon-bonded hydrogen atoms, the total amount of components (a) and (b) being preferably more than 30% by weight of the composition.
    Type: Grant
    Filed: June 6, 1974
    Date of Patent: November 8, 1977
    Assignee: Shinetsu Chemical Company
    Inventors: Minoru Takamizawa, Humio Okada, Nobuyuki Hasebe, Hiromi Toida
  • Patent number: 4029619
    Abstract: Vinyl chloride monomer is polymerized in aqueous medium under the influence of oil soluble polymerization initiators in the presence of alkali metal salts of higher fatty acid, higher alcohols and/or higher fatty acids, and hydroxides of alkali metals in certain amounts respectively, to produce vinyl chloride resin, stable for making resin/plasticizer pastes, mostly composed of particles having diameters lying between 0.1 and 2 microns. The resins are suitable for making resin/plasticizer pastes that have a low initial viscosity, little change in viscosities during storage, good thermal stability and excellent degassing property. Reduced deposition of polymer scales on the walls of the polymerization vessels was successful.
    Type: Grant
    Filed: December 5, 1972
    Date of Patent: June 14, 1977
    Assignee: Shinetsu Chemical Company
    Inventors: Shigenobu Tajima, Kazuhiko Kurimoto
  • Patent number: 4011247
    Abstract: Starting from an organohydrogenpolysiloxane having at least two hydrogen atoms directly bonded to the silicone atoms, an organohydrogenpolysiloxane is obtained in which part of the silicon-bonded hydrogen atoms have been converted into organic groups and the remaining silicon-bonded hydrogen atoms are left unreacted. The starting organohydrogenpolysiloxane is brought to the partial addition reaction with less than equivalent amount of an organic unsaturated compound having aliphatic double bond in the molecule in the presence of a platinum catalyst, and the reaction mixture is subjected to distillation while the platinum catalyst is deactivated by added benzothiazole or derivatives thereof, thus providing for the production of the organohydrogenpolysiloxane of the invention in reproducibly in high yield. The compounds are useful as crosslinking agents in the manufacture of various silicone products.
    Type: Grant
    Filed: October 4, 1974
    Date of Patent: March 8, 1977
    Assignee: Shinetsu Chemical Company
    Inventors: Yasuhiko Sato, Hiroshi Inomata, Toshio Shiobara
  • Patent number: 4000108
    Abstract: Silicone resin-based molding compositions filled with spherical glass bodies, i.e., void-free glass beads or hollow glass spheres, have the possibility to give molded articles colored in white or light-tone colors different from conventional molding compositions filled with other inorganic fillers which are rather highly abrasive against metal surfaces of the apparatus employed for processing the molding compositions and which causes dark stains to the molding compositions leading to the necessity to color them in black or dark-tone colors in order to mask the stains. The molded articles fabricated with the molding compositions of the present invention colored in white or light-tone colors are very attractive where sanitary cleanliness or fashionableness is important.
    Type: Grant
    Filed: September 30, 1974
    Date of Patent: December 28, 1976
    Assignee: Shinetsu Chemical Company
    Inventors: Kiyoshi Yokokawa, Yasuhisa Tanaka, Jun Koizumi, Noboru Shimamoto, Tokio Sekiya
  • Patent number: 3996195
    Abstract: An improved curable organosilicon composition is formulated by blending a resin-type organopolysiloxane containing vinyl groups equivalent to 2.0 to 40 mole % of the organic groups with an organohydrogenpolysiloxane containing at least 2 hydrogen atoms directly bonded to the silicon atoms and epoxy and/or ester groups bonded to the silicon atoms through carbon atoms in the presence of a platinum catalyst, in which hydrosilation reaction takes place between the vinyl groups and the silicon-bonded hydrogen atoms to give crosslinked structure to volume cured. The compositions have a sufficiently long pot life and on curing create strong adhesion to metal, glass and ceramic and the like surfaces. The cured compositions have very high transparency and good thermal stability, and they are useful for various applications such as the manufacture of electronic parts.
    Type: Grant
    Filed: November 15, 1974
    Date of Patent: December 7, 1976
    Assignee: Shinetsu Chemical Company
    Inventors: Yasuhiko Sato, Hiroshi Inomata
  • Patent number: 3993839
    Abstract: Printability improving agents for molded synthetic resin products comprising organosiloxy titanic acid esters prepared by co-condensation of a titanic acid ester having the formula Ti(OR.sup.1).sub.4 where R.sup.1 is a monovalent hydrocarbon with a silane or siloxane compound having hydroxy or acetoxy radicals bonded to silicon atoms. Their solutions in an organic solvent are applied to surfaces of molded silicone rubber, polyester or other synthetic resin products in order to make the treated surfaces far more printable with or acceptable to various inks and, as a result, the printed ink will be safe from abrasion.
    Type: Grant
    Filed: January 15, 1975
    Date of Patent: November 23, 1976
    Assignee: Shinetsu Chemical Company
    Inventors: Yasuhiko Sato, Akitoshi Komiya
  • Patent number: 3992355
    Abstract: Heat-curable organopolysiloxane compositions comprising a diorganopolysiloxane having at least two vinyl groups per molecule and a viscosity exceeding 100 centistokes at 25.degree. C, an inorganic filler, an organohydrogenpolysiloxane containing at least two Si--H linkages per molecule, a platinum catalyst, a hydrazine compound and optionally, an organic peroxide, which have an improved storage stability and allow for imparting an excellent flame retardancy and mechanical strength to the cured material.
    Type: Grant
    Filed: January 21, 1975
    Date of Patent: November 16, 1976
    Assignee: Shinetsu Chemical Company
    Inventors: Kunio Itoh, Takeo Yoshida, Hironao Fujiki
  • Patent number: 3989733
    Abstract: Cyclic polydiorganosiloxanes, in particular, cyclic trisiloxanes are continuously prepared from mixed polydiorganosiloxane, the starting material, by subjecting them to thermal cracking and rectification in a reactor composed of a column, vertically held, comprising a catalyst zone at the lower part in which the thermal cracking takes place to produce cyclic polydiorganosiloxanes and a rectification zone at the upper part in which the cyclic polydiorganosiloxanes are rectified into several fractions and a still positioned below the column. The cyclic polydiorganosiloxanes have structures different from the starting polydiorganosiloxanes.
    Type: Grant
    Filed: December 28, 1973
    Date of Patent: November 2, 1976
    Assignee: Shinetsu Chemical Company
    Inventors: Haruo Okamoto, Isao Yanagisawa
  • Patent number: 3983180
    Abstract: A process for preparing methyl chloride by reacting hydrogen chloride with methanol in the liquid-phase non-catalytic reaction, employing a reaction system comprising a reactor and two distillation columns, each being operated under a different pressure, to greatly increase the space time yield and the conversion of hydrogen chloride and methanol, and at the same time to reduce the production of dimethyl ether as a byproduct. The raw materials used may be either gaseous or liquid; they may contain a large amount of water or gases insoluble in water. By this process, hydrogen chloride gas and diluted hydrochloric acid that are produced as a byproduct or waste in various chemical processes can be effectively utilized.
    Type: Grant
    Filed: October 2, 1974
    Date of Patent: September 28, 1976
    Assignee: Shinetsu Chemical Company
    Inventors: Kiichi Habata, Shozo Tanaka, Hitoyuki Araki
  • Patent number: 3979482
    Abstract: The oxidation of a high polymer such as polyvinyl chloride or polyolefin, which oxidation causes cleavages of carbon-carbon bonds in the main chains thereof to degrade the high polymer into lower molecular weight compounds, is remarkably accelerated when the high polymer is impregnated with a halogenated compound having a carbonyl group or carbonyl groups and exposed to sunlight or is irradiated with ultraviolet radiation in an ambient atmosphere of oxygen or a gas containing oxygen. This acceleration of the oxidation makes possible easy destruction of a shaped article made of such a high polymer.
    Type: Grant
    Filed: November 29, 1974
    Date of Patent: September 7, 1976
    Assignees: Tsutomu Kagiya, Shinetsu Chemical Company, Tekkosha Co., Ltd.
    Inventors: Tsutomu Kagiya, Kunihiko Miyoshi, Katsuo Takemoto
  • Patent number: 3975446
    Abstract: Unsaturated ketones represented by the general formula ##EQU1## are successfully synthesized with very good yield from corresponding unsaturated alcohols and diketene in a single-step process in which the esterification reaction and the decarboxylation reaction take place concurrently by the synergistic action of the catalyst system composed of a high-boiling amine and an aluminum trialkoxide.
    Type: Grant
    Filed: June 25, 1974
    Date of Patent: August 17, 1976
    Assignee: Shinetsu Chemical Company
    Inventors: Tetsuro Kitagaki, Akira Yamamoto, Toshinobu Ishihara
  • Patent number: 3957523
    Abstract: When a mixture comprising 30 to 70% by weight of an enterosoluble cellulose derivative containing a monoester linkage with a polybasic acid, such as, hydroxypropyl methylcellulose phthalate, and 70 to 30% by weight of a digestive fluid-insoluble cellulose derivative, such as, ethylcellulose is used as a coating material for solid medicines, the rate of gradual release of active ingredients of the medicine in the intestinal tracts can be appropriately controlled.
    Type: Grant
    Filed: March 28, 1974
    Date of Patent: May 18, 1976
    Assignee: Shinetsu Chemical Company
    Inventors: Shigeru Ohno, Noboru Hoshi, Fujio Sekigawa
  • Patent number: 3945958
    Abstract: When vinyl chloride or a mixture of monomers containing vinyl chloride as its main component is subjected to suspension-polymerization, in the presence of a polymerization initiator, employing as a suspending agent an aqueous medium consisting of two kinds of water-soluble cellulose ethers, the 2% aqueous solution of one of which has a viscosity of at most 100 cps at 20.degree.C, and that of the other has a viscosity of at least 400 cps at 20.degree.C, the product obtained will be a porous polymer superior not only in uniformity of particle size, and absorptivity of plasticizers and liquid heat-stabilizers but also in processability.
    Type: Grant
    Filed: May 31, 1974
    Date of Patent: March 23, 1976
    Assignee: Shinetsu Chemical Company
    Inventors: Shunichi Koyanagi, Hajime Kitamura, Toshihide Shimizu
  • Patent number: 3936476
    Abstract: Silicone compositions consisting essentially of 100 parts by weight organopolysiloxane, 20-200 parts by weight finely divided silica filler, 5-100 parts by weight finely divided manganese carbonate, and 5-1,000 ppm platinum alone or in a platinum containing material, based on the weight of the organopolysiloxane. Finished products prepared by molding the compositions exhibit particularly excellent flame-proofing and improved degrees of permanent strain caused by stress. Particularly preferred are silicone compositions with 5-100 parts by weight of finely divided manganese carbonate having a particle size from about 1.mu. to about 50.mu..
    Type: Grant
    Filed: January 8, 1975
    Date of Patent: February 3, 1976
    Assignee: Shinetsu Chemical Company
    Inventors: Kunio Itoh, Takeo Yoshida