Shin-etsu Chemical Co., Ltd.

Toshihide Shimizu

Mikio Watanabe

Ichiro Kaneko

Minoru Shigemitsu

Shunichi Koyanagi

Hajime Kitamura

Yoshiteru Shimakura

Susumu Ueno

Genji Noguki

Tamaki Iida

Toshihiko Nakano

Tatsuya Fujimoto

Seiji Fukuda

Kenji Fushimi

Niichiro Hasegawa

Takanori Sato

Takeo Yoshida

Masahiro Usuki

Osamu Hayashida

Takeo Inoue

Tokuji Abe

Michinori Tsuchida

Yoshio Inouye

Sensaku Katsushima

Sensaku Katusima

Yasuo Furukawa

Hajime Kutamura

A process for producing a polymer by polymerizing in a polymerization vessel a monomer having an ethylenic double bond is provided. In this process, the polymerization vessel has a polymer scale preventive coating film on its inner wall surfaces and other surfaces with which the monomer comes into contact during polymerization. The coating film is formed by coating a coating liquid containing (A) a compound selected from the group consisting of an aromatic compound having 5 or more conjugated &pgr; bonds and a heterocyclic compound having 5 or more conjugated &pgr; bonds, and (B) a compound selected from the group consisting of an inorganic colloid, a chelate reagent, a metal compound that produces a metal ion capable of forming a complex having at least two coordination numbers, and an acid; the coating liquid being coated by means of steam as a carrier. This process can shorten the time for forming coating films of scale preventive agents to improve productivity, can improve the effect of preventing polymer scales, can make colored particles less which mix into polymer products, can lessen fish eyes and initial discoloring of formed products and can improve the quality of polymeric products and their formed or molded products.

Process for producing a polymer by polymerization of a monomer having an ethylenic double bond

A process for producing a polymer by polymerizing in a polymerization vessel a monomer having an ethylenic double bond is provided. In this process, the polymerization vessel has a polymer scale preventive coating film on its inner wall surfaces and other surfaces with which the monomer comes into contact during polymerization. The coating film is formed by coating a first coating liquid containing a compound selected from the group consisting of an aromatic compound having 5 or more conjugatedbonds and a heterocyclic compound having 5 or more conjugatedbonds and a second coating liquid containing at least one hydrophilic compound selected from the group consisting of a water-soluble polymeric compound, an inorganic colloid, an inorganic salt and an acid; the first coating liquid and the second coating liquid being simultaneously coated by means of steam as a carrier. This process can shorten the time for forming coating films of scale preventive agents to improve productivity, can improve the effect of preventing scales, can make colored particles less mix into polymer products obtained by this process, can lessen fish eyes and initial discoloring of formed products and can improve the quality of polymeric products and their formed or molded products.

There is provided a polymer scale deposition preventive agent, comprising an alkaline solution of a condensation product having a molecular weight of 500 to 1,000,000 obtained by condensing a dimer compound of 2,3-dihydroxynaphthalene with formaldehyde. By polymerizing vinyl chloride or a monomer mixture containing vinyl chloride in a polymerization vessel wherein a coating film made of said polymer scale deposition preventive agent has been formed on the inner wall surface and the like, polymer scale is effectively prevented from depositing not only on an agitation apparatus but also on areas near the interface between a gas phase and a liquid phase, which prevention of the polymer scale deposition is conventionally difficult. Thus, a vinyl chloride polymer can be obtained which contains colored foreign matters, fish eyes, etc. in small amounts and is small in initial discoloration and is good in quality.

Composition comprising condensation product of dimer of 2,3-dihydroxynaphthalene and formaldehyde for polymerization

An improved process for producing a polymer by polymerizing a monomer having an ethylenic double bond in a polymerization vessel having a polymer scale preventive coating film on its inner wall surfaces, etc. is provided. The coating film is formed by coating a first coating liquid containing a compound selected from the group consisting of an aromatic compound having 5 or more conjugated &pgr; bonds and a heterocyclic compound having 5 or more conjugated &pgr;bonds, and then coating a second coating liquid a dye and/or pigment on the first layer. The first and second coating liquids are applied by means of steam as a carrier. The second layer has a surface having a contact angle to water of less than 60&deg; after its surface has been kept in contact with a solution of mixture of water and a vinyl chloride monomer in a weight ratio of 1:1 at 50&deg; C. for 1 hour. This process can shorten the time for forming the coating film to improve productivity, can improve the effect of preventing adhesion of polymer scale, can make colored particles less mix into polymer products obtained by this process, can lessen fish eyes and initial discoloring of formed products and can improve the quality of polymeric products and their formed or molded products.

A rust preventive composition including (a) a silicic acid compound and (b) an aromatic amine-based condensation product is provided, which is effective in preventing a Zn-based metallic coating from rusting. Rusting is prevented by forming a coating film contaning the components (a) and (b) on the surface of the Zn-based metallic coating formed on a base such as a metal plate. The resulting coating film exhibits an excellent corrosion resistance, gives no fear of a health problem such as carcinogensis and provides a desirable black or blackish appearance to a metal surface. In an embodiment wherein a second coating film containing a silicic acid compound is formed on the first coating film, the corrosion resistance is further improved.

Rust prevention

Disclosed is a rust-preventive composition comprising (A) an aromatic compound i) containing a group selected from the group consisting of an &mdash;N&boxH;N&mdash; group, a >C&boxH;N&mdash; group, a >C&boxH;O group and an &mdash;N&boxH;O group and ii) having an absorption band in a visible region of from 530 nm to 750 nm; (B) a colloidal silica; (C) a film-forming polymeric compound containing in one molecule a group selected from the group consisting of an &mdash;OH group and a &mdash;COOH group; and (D) an organic solvent. This composition, having been coated on metal surfaces, provides a sufficient corrosion resistance without making any chromating treatment.

Rust preventive composition

An aluminum nitride composition including an aluminum nitride powder and an aromatic amine-based condensate is provided. In the composition, the aluminum nitride may hardly undergo decomposition even under severe conditions of high temperature and high humidity, and the electrical insulating properties and high thermal conductivity inherent in aluminum nitride powder can be maintained under such severe conditions. Accordingly, this composition is useful as a durable heat-dissipating composition, in particular, as a heat-dissipating coating material, grease or sheet.

Aluminum nitride composition

A conductive organopolysiloxane composition is provided which includes (A) 100 parts by weight of an organopolysiloxane; and (B) 0.1 to 800 parts by weight of a conductive material obtained by subjecting a member selected from the group consisting of a conductive metal, a conductive metal compound, a filler surface-treated with a conductive metal and a filler surface-treated with a conductive metal compound, to surface treatment with a compound selected from the group consisting of a compound represented by the formula (1) and a compound represented by the formula (2). ##STR1## wherein R.sup.1 represents --O-- or --NH--, and R.sup.2 represents a hydrogen atom or a phenyl group. This composition is useful for the formation of a silicone rubber having a sufficient electrical conductivity and also stably retainable of electrical conductivity almost without undergoing a change in electrical conductivity even in a high-temperature environment.

Conductive organopolysiloxane composition

Process of producing vinyl chloride polymer by using condensation

An improved process for producing a polymer by polymerizing a monomer having an ethylenic double bond in a polymerization vessel having a polymer scale preventive coating film on its inner wall surfaces, etc. is provided. The coating film is formed by coating a first coating liquid containing a compound selected from the group consisting of an aromatic compound having 5 or more conjugated .pi. bonds and a heterocyclic compound having 5 or more conjugated .pi. bonds, and then coating a second coating liquid on the first layer. The first and second coating liquids are applied by means of steam as a carrier. The second layer has a surface having a contact angle to water of less than 60.degree. after its surface has been brought into contact with a solution of mixture of water and a vinyl chloride monomer in a weight ratio of 1:1, at 50.degree. C. for 1 hour. This process can shorten the time for forming the coating film to improve productivity, can improve the effect of preventing adhesion of polymer scale, can make colored particles less mix into polymer products obtained by this process, can lessen fish eyes and initial discoloring of formed products and can improve the quality of polymeric products and their formed or molded products.

Process for producing a polymer by polymerization of a monomer having an

A polymer scale preventive agent for use in polymerization of a monomer having an ethylenically unsaturated double bond, comprising an alkaline solution containing (A) a condensation product having a molecular weight of 400 to 50,000 obtained by condensing a quinone compound. This agent is applied to the inner wall surfaces of a polymerization vessel, and dried to form a coating. Such a vessel is effective in preventing polymer scale deposition, not only on the areas located in the liquid-phase region but also on the areas around the interface between the gas and liquid phases in the vessel, and is useful in producing a polymer that shows few fish eyes and good whiteness when formed into sheets or the like.

Polymer scale preventive agent comprising a condensation product of a

A polymer scale deposition preventive agent comprising (a) an aromatic compound having at least eight conjugated .pi. bonds and having a molecular weight of 1,000 or more, and (b) a polyalkylene oxide having a weight-average molecular weight of 2,000 or more, wherein the weight ratio of the component (a) to the component (b) is 100/500 to 100/1, can prevent surely the deposition of polymer scale even in a polymerization system containing a monomer, such as styrene, acrylic acid esters or acrylonitrile, which has a high solvency for a coating film consisting of the conventional polymer scale deposition preventive agent.

Polymer scale depostion preventive agent and a process for producing

A polymer scale preventive agent for use in polymerization of a monomer having an ethylenically unsaturated double bond, comprising an alkaline liquid containing a condensation product of: (A) at least one compound selected from the group consisting of azo compounds having at least two amino groups and azoxy compounds having at least two amino groups, and (B) a quirtone compound, is disclosed. Also disclosed is a process for producing a polymer, which comprises polymerizing the monomer in a polymerization vessel having a coating on its inner wall, whereby deposition of polymer scale is prevented, the coating having been formed by applying the scale preventive agent and drying the applied agent. According to the process, polymer scale deposition can be effectively prevented, not only on the areas located in the liquid-phase region but also on the areas around the gas-liquid interface in the vessel, so that the need to remove polymer scale every run of polymerization is eliminated and productivity is thereby enhanced. Besides, the process yields a polymer that shows few fish eyes and good whiteness when formed into sheets or the like.

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Urayasu, Japan

Toshihide Shimizu