Shin-etsu Chemical Co., Ltd.

Ryuichi Saito

Takeshi Kinsho

Tsutomu Ogihara

Takaaki Shimizu

Tatsushi Kaneko

Hideshi Kurihara

Tadashi Amano

Mutsuo Nakashima

Mikio Aramata

Tetsuya Inukai

Kazuyuki Asakura

Hajime Ishizaka

Takashi Kobayashi

Masahiro Yuyama

Toshiaki Takahashi

Tatsuya Fujimoto

Toshihiko Kawakubo

Yoshinori Nakahara

Ichiro Hara

Method of producing vinyl-based polymer

A production process for a vinyl-based polymer is provided. The production process comprises a step for polymerizing a vinyl-based monomer by a radical reaction within an aqueous medium in a polymerization vessel, and a step for supplying a reaction inhibitor with a melting point of no more than 40&deg; C. from a reaction inhibitor supply tank to the polymerization vessel via a reaction inhibitor supply pipe. The reaction inhibitor supply tank and the reaction inhibitor supply pipe are heated, and the reaction inhibitor is added to the polymerization vessel in a liquid state with a viscosity of no more than 200 mPa&middot;s. The reaction inhibitor can be added to the polymerization mixture without the use of an organic solvent even at low temperatures, and problems such as the solidification of the reaction inhibitor inside the supply tank or piping, and subsequent blocking of the piping do not occur.

Production process for vinyl-based polymer

A process for producing a vinyl chloride polymer, including the steps of (a) subjecting a vinyl chloride monomer alone or a monomer mixture containing a vinyl chloride, to suspension polymerization in water; (b) subjecting the resultant vinyl chloride polymer slurry to stripping to remove an unreacted monomer remaining therein; and (c) dehydrating the polymer slurry having been subjected to stripping. In the polymerization step (a), the ratio of water/monomer is set in a weight ratio of from 0.80 to 1.50, and the viscosity at 20&deg; C. of the polymer slurry to be fed to the stripping step is previously kept adjusted to 0.30 Pa&middot;s or lower. In the stripping step (c), the residual unreacted monomer in the polymer slurry can efficiently be removed using steam in a smaller quantity, thus the vinyl chloride polymer can be produced at a high productivity.

Process for producing vinyl chloride polymer with low residual monomer

When oganohalosilanes are prepared by charging a reactor with a contact mass containing metallic silicon and a copper catalyst and introducing an organohalide-containing gas into the reactor to effect the direct reaction, 50-10,000 ppm of bronze phosphide is added to the contact mass. The invention is successful in efficiently producing organohalosilanes in a high STY and low T/D.

Preparation of organohalosilanes

Suspension polymerization of vinyl chloride in an aqueous medium is carried out in the presence of an oil-soluble polymerization initiator which is a combination of diacylperoxide compound and t-hexylperoxy diglycolate, the former having a half-life period of 10 hours at 30 to 50.degree. C. in benzene (0.05 mol/L). The resulting polymer gives a high-quality molded product which is free of odor and less liable to initial discoloration.

Polymerization of vinyl chloride with peroxide mixtures

In a process for producing a vinylidene fluoride resin by polymerizing vinylidene fluoride or a mixture of vinylidene fluoride and a vinyl monomer copolymerizable with vinylidene fluoride, a portion of an iodide compound represented by the formula: X-R.sub.f -X wherein R.sub.f is a divalent organic group containing at least two divalent fluoroalkyl ether groups: and X's are independently an iodine atom or a fluorine atom, provided that at least one of the X's is an iodine atom; is added to start the polymerization, and the remainder of the iodide compound is further added dividedly at least twice in the course of the polymerization. This process enables to obtain a vinylidene fluoride resin having a viscosity-average molecular weight of 150,000 or more and also having a superior water repellency. This resin has good mechanical strength and release properties and also can be well processed into films.

Process for producing vinylidene fluoride resin

A silacyclohexane compound represented by the following general formula (I). ##STR1## In this formula, R denotes a linear-chain alkyl group with 1-10 carbon atoms, a branched-chain alkyl group with 3-8 carbon atoms, a mono- or di-fluoroalkyl group with 1-10 carbon atoms, an alkoxyalkyl group with 2-7 carbon atoms, or an alkenyl group with 2-8 carbon atoms. ##STR2## is trans-1-silacyclohexylene or trans-4-silacyclohexylene group whose silicon at position 1 or position 4 has a substitutional group(s) of H, F, Cl or CH.sub.3. X denotes a R, OR, CN, F, Cl, CF.sub.3, CF.sub.2 Cl, CHFCl, OCF.sub.3, OCHF.sub.2, OCF.sub.2 Cl, OCHFCl, --(O).sub.m --CY.sub.1 .dbd.CX.sub.1 X.sub.2 (m denotes 0 or 1, Y.sub.1 and X.sub.1 respectively denote H, F or Cl, and X.sub.2 denotes F or Cl) or --O--C.sub.r F.sub.s H.sub.2r+1-s is (r denotes an integral of 2 to 4 and s denotes an integral of 1 to 7) group. Y denotes H or F. Z denotes H or F.

Silacyclohexane compound, a method of preparing it and a liquid crystal

Liquid crystal compositions which can improve the low .DELTA.n (refractive index anisotropy) of conventional liquid crystal compositions containing a silacyclohexane compound and which retain a low viscosity and hence show no decrease in response speed. Liquid crystal compositions having a high .DELTA.n of 0.13 to 0.25, a low viscosity of 30 cp or less, a low threshold voltage and a high voltage holding ratio can be obtained by adding thereto, as a required component, a compound having both a silacyclohexane ring and a tolan structure, or a miture of a compound having a silacyclohexane ring and a compound having a tolan structure.

Liquid crystal compositions and liquid crystal display elements

A silacyclohexane compound represented by the following general formula (I). ##STR1## In this formula, R denotes a linear-chain alkyl group with a carbon number of 1-10, a mono- or di- fluoro-alkyl group with a carbon number of 1-10, a branched-chain alkyl group with a carbon number of 3-8, an alkoxyalkyl group with a carbon number of 2-7, or an alkenyl group with a carbon number of 2-8. ##STR2## denotes trans-1-sila-1,4-cyclohexylene or trans-4-sila-1,4-cyclohexylene group whose silicon at position 1 or position 4 has a substitutional group(s) of H, F, Cl or CH.sub.3. X denotes a CN, F, Cl, CF.sub.3, CF.sub.2 Cl, CHFCl, OCF.sub.3, OCHF.sub.2, OCF.sub.2 Cl, OCHFCl, R or OR group (R is the same as defined in the general formula (I)). Y.sub.2 and Z denote H or F, independently to each other. Y.sub.1 denotes H, F or Cl.

A silacyclohexanone compound represented by the following general formula (I). ##STR1## wherein Ar denotes a phenyl group or a tolyl group. R denotes a tolyl group, a linear-chain alkyl group with a carbon number of 2-10, a mono- or di-fluoroalkyl group with a carbon number of 1-10, a branched-chain alkyl group with a carbon number of 3-8 or an alkoxyalkyl group with a carbon number of 2-7. Also, a method of manufacturing silacyclohexane-type liquid crystal compounds represented by the general formula (II) ##STR2## and the general formula (III) ##STR3## which are derived from this compound.

Silacyclohexanone compound and a method of preparing a

A liquid crystal composition comprising a silacyclohexane compound represented by the following formula (I): ##STR1## wherein R and R' denote an alkyl group, a mono- or di-fluoroalkyl group, an alkoxyalkyl group or an alkenyl group; at least one of ##STR2## denotes a silacyclohexylene group whose silicon at positions 1 or 4 has a substitutional group of H, F, Cl of CH.sub.3, and the other denotes a silacyclohexylene group whose silicon at positions 1 or 4 has a substitutional group of H, F, Cl or CH.sub.3 or a cyclohexylene group; and 0-2 of the substitutional groups X on the aromatic rings denote F and the remaining X's denote H.

A silacyclohexane compound of formula (I): ##STR1## wherein R denotes a linear-chain alkyl group, a mono- or di-fluoroalkyl group, a branched-chain alkyl group, an alkoxyalkyl group, or an alkenyl group: at least one of ##STR2## denotes a 1-sila-1,4-cyclohexylene or a 4-sila-1,4-cyclohexylene group whose silicon at position 1 or 4 is H, F, Cl or CH.sub.3, and the other denotes a 1,4-cyclohexylene group, a 1-sila-1,4-cyclohexylene or a 4-sila-1,4-cyclohexylene group whose silicon at position 1 or 4 is H F, Cl or CH.sub.3 ; X denotes a substitutional group at an equatorial position, specifically CN, an alkyl group with its end group replaced by a trifluoromethyl group, an alkoxy group, an alkanoyloxy group, an alkoxycarbonyl group, a linear-chain alkyl group, or an alkoxyalkyl group; Y denotes a group at an axial position, specifically H or CN when Y is connected to a carbon atom in said (B) group or H, F, Cl or CH.sub.3 when Y is connected to a silicon atom in said (B) group.

Silacyclohexane compound, a method of preparing it and a liquid cyrstal

A silacyclohexane compound represented by the following general formula (I). ##STR1## In this formula, R denotes hydrogen, a linear-chain alkyl group with a carbon number of 1-10, a branched-chain alkyl group with a carbon number of 3-8, an alkoxyalkyl group with a carbon number of 2-7, a fluoroalkyl group with a carbon number of 1-10 in which one or two hydrogen atoms are substituted by florine atom(s), or an alkenyl group with a carbon number of 2-8. For the groups ##STR2## at least one of these is a trans-1-sila-1,4-cyclohexylene or trans-4-sila-1,4-cyclohexylene group whose silicon at position 1 or position 4 has a substitutional group(s) of H, F, Cl or CH.sub.3, and the other denotes a trans-1,4-cyclohexylene group. X denotes a CN, F, Cl, CF.sub.3, CF.sub.2 Cl, CHFCl, OCF.sub.3, OCHF.sub.2, OCF.sub.2 Cl, OCHFCl, R or OR group (R is the same as defined earlier). Y denotes H or F. Z denotes H or F.

There is provided a silacyclohexane compound and method of making same. The silacyclohexane compound has the following formula (1): ##STR1## wherein R denotes a linear-chain alkyl group with a carbon number of 1-10, a mono- or di-fluoroalkyl group with a carbon number of 1-10, a branched-chain alkyl group with a carbon number of 3-8, an alkoxyalkyl group with a carbon number of 2-7, or an alkenyl group with a carbon number of 2-8, ##STR2## denotes a trans-1-sila-1,4-cyclohexylene or a trans-4-sila-1,4-cyclohexylene group having silicon at positions 1 or 4 with substitutional group(s) of H, F, C1 or CH.sub.3 ; n denotes 0 or 1; L.sub.1 and L.sub.2 independently denote H.F, C1, CN or CH.sub.3 ; L.sub.3 denotes F; m denotes O, 1 or 2; and X denotes H, CN, F, C1, CF.sub.3, CC1F.sub.2, CHFC1, OCC1F.sub.2, OCHFC1, OCHF.sub.2, OCF.sub.3, R or OR group.

A silacyclohexane compound represented by the following general formula (1): ##STR1## wherein R denotes a linear-chain alkyl group with a carbon number of 1-10, a mono- or di-fluoroalkyl group with a carbon number of 1-10, a branched-chain alkyl group with a carbon number of 3-8, an alkoxyalkyl group with a carbon number of 2-7, or an alkenyl group with a carbon number of 2-8, and at least one of ##STR2## denotes a trans-1-sila-1,4-cyclohexylene or a trans-4-sila-1,4-cyclohexylene group whose silicon at position 1 or position 4 has a substitutional group(s) of H, F, Cl or CH.sub.3 and the other is a trans-1,4-cyclohexylene group, X denotes a CN, F, F, Cl, CF.sub.3, OCF.sub.3, OCHF.sub.2, OCHFCl, CF.sub.2 Cl, OCF.sub.2 Cl, R or OR group, Z.sub.1 denotes H, F or Cl, and Z.sub.2 denotes H or F.

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Niigata-ken, Japan

Ryuichi Saito