Abstract: Matte vinyl chloride polymers are prepared by suspension polymerizing a vinyl chloride monomer or a vinyl monomer mixture mainly comprising vinyl chloride in an aqueous medium in the presence of (A) a polyfunctional monomer having at least two ethylenic double bonds in a molecule and (B) a polymeric matting agent containing 3 to 25% by weight of a tetrahydrofuran-insoluble gel fraction. The polymers are effectively moldable and present uniform matte effect.

Abstract: The present invention relates to a coating solution for preventing adhesion of polymer scale and a method for preventing scale adhesion during preparation of polymers which can provide polymers having high quality without coloring thereof while preventing adhesion of polymer scale to a polymerizer when a monomer having an ethylenically unsaturated double bond is polymerized. A coating solution for preventing adhesion of polymer scale which comprises anaphthoquinone natural dyestuffs, anthraquinone natural dyestuffs, tannin natural dyestuffs, xanthone natural dyestuffs, flavonoid natural dyestuffs, or/and benzoquinone natural dyestuffs and a polyvinyl alcohol having a degree of saponification of not less than 70 mole % was applied on at least a part of a polymerizer which comes in contact with a monomer having an ethylenically unsaturated double bond and was dried to give a coating film during polymerization thereof.

Abstract: An edged medical tool, such as scalpels and injection needles, is imparted with unexpectedly improved incisiveness by first providing a carbonaceous coating layer of 1 to 20 nm thickness having a crystalline structure of diamond by a method of plasma-induced vapor-phase deposition in an atmosphere of a mixture of hydrogen gas and a hydrocarbon gas at a microwave frequency of 1 to 10 GHz and then etching the thus formed diamond-like coating layer in a plasma of hydrogen gas to such an extent that the thus etched surface has a roughness of 0.5 to 5 nm.

Abstract: An efficient and reliable method and a system are proposed for detecting colored foreign particles in a white or light-colored powdery product such as a polyvinyl chloride resin with an object of product inspection and quality control. The method comprises the steps of eliminating static electricity from the powder, e.g., by spraying ethyl alcohol, continuously feeding the powder at a controlled rate on to a belt conveyor to form a uniform powder layer having a flat and even surface thereon, bringing the powder layer below a reflection-type laser-beam scanning detector projecting a laser beam with scanning and receiving the reflected beam and monitoring the output signals coming out of the detector.

Abstract: The polyvinyl chloride (PVC) resin-based composition of the invention gives a molded article which suffers little from the disadvantageous phenomenon of surface whitening as is sometimes unavoidable when a conventional PVC resin-made article is prolongedly kept under adverse conditions as in hot water or in a high-temperature, high-humidity atmosphere. The composition characteristically comprises a limited amount of a partially saponified polyvinyl alcohol having an average degree of polymerization of 150 to 600 and a degree of saponification of 20 to 55% as a special additive in an amount of 0.8 to 5.0% by weight based on the PVC resin. The resin composition is also less subject to the disadvantage of a decrease in the transparency of the resin articles even when the resin composition is compounded with a metal-containing heat stabilizer such as organotin mercaptides.

Abstract: In a metal mold exchanging apparatus for use in an injection molding machine of the type wherein a metal mold is exchanged, there are provided a metal mold loading and unloading unit including a pair of metal mold supporting plates which are vertically spaced with a predetermined distance therebetween and an elevator for simultaneously raising and lowering the metal mold supporting plates for rendering the height of each one of the metal mold supporting plates to be equal to the height of position at which the metal mold is exchanged.

Abstract: A process for preparing a vinyl chloride polymer by suspension polymerization with use of (A) a particular partially saponified polyvinyl alcohol having a high polymerization degree and a high saponification degree, (B) a particular hydoxypropyl methyl cellulose and (C) a particular partially saponified polyvinyl alcohol having a low polymerization degree and a low saponification degree as dispersion stabilizers, in a polymerization vessel coated with a scale preventive on its inner wall etc., wherein an (A)Agent/(B)agent ratio is 4/6 to 24/1 in weight ratio; Agent (C) is used in an amount of 0.001 to 0.1% by weight based on the charged monomers; Agent (C) is charged with or after the charging of Agent (A) and (B), and, the particle diameter of Agent (C) in the suspension mixture is controlled to not higher than 100 .mu.m. A vinyl chloride polymer having a high bulk density and high porosity can be produced without formation of polymer scale.

Abstract: A microtome blade made of, for example, sapphire is imparted with greatly improved cutting power as well as durability and anti-corrosion resistance by providing a coating layer of diamond thereon. Such a coating layer can be formed by subjecting a base blade to a treatment of plasma-induced chemical vapor deposition of diamond in an atmosphere of a gaseous mixture of a hydrocarbon compound and hydrogen followed by a heat treatment at 700.degree.-1300.degree. C. to expel any adsorbed impurities in the diamond layer.

Abstract: The invention provides a method for the preparation of a flexible base for printed circuit board of the type formed of lamination of a flexible sheet-like polymeric base and a metal, e.g. copper, foil adhesively bonded to the surface thereof by use of an adhesive, in which the surface of the polymeric base prior to bonding of the metal foil is subjected to exposure to low temperature plasma so that the adhesive bonding strength between the polymeric base and the metal foil can be greatly improved.

Abstract: This process is a process for production of a vinyl chloride polymer by suspension polymerization or emulsion polymerization of vinyl chloride monomer or a mixture of vinyl chloride monomer with a vinyl monomer copolymerizable with said vinyl chloride monomer in an aqueous medium, characterized in that the polymerization is carried out in a polymerizer, the inner wall surface and portions of the auxiliary equipment thereof which may come into contact with the monomer during polymerization being previously coated with a scaling preventive comprising at least one selected from dyes, pigments and aromatic or heterocyclic compounds having at least 5 conjugated .pi. bonds, while controlling the chloride ion concentration in the reaction mixture to not higher than 100 ppm. According to said process, scaling onto the inner wall surface of a polymerizer, etc. during polymerization can be prevented effectively and surely.

Abstract: A composite polymeric material having a high permeability to oxygen is proposed comprising a vinyl chloride moiety, an organosilicon moiety and, optionally, a third polymeric moiety. Such a composite polymeric material can be prepared in several ways including copolymerization of vinyl chloride monomer, a polymerizable organosilicon compound and, optionally, a third monomer, graft-polymerization of a polymerizable organosilicon compound on to a polyvinyl chloride resin, graft-polymerization of vinyl chloride on to an organopolysiloxane, graft-copolymerization of vinyl chloride and a polymerizable organosilicon compound on to a third polymer and blending of the respective polymeric components.

Abstract: The invention provides a formulation of a vinyl chloride resin-based composition suitable for preparing floppy disc jackets having high heat resistance with a Clash-Berg temperature of 75.degree. C. or higher comprising, as the essential components, (A) a copolymer of viny chloride with a N-substituted maleimide as the comonomer, optionally in combination with a homopolymeric polyvinyl chloride resin, (B) an impact-strength improving agent which is preferably a vulcanizable synthetic rubber and (C) carbon black.

Abstract: The inventive shaped body for gas separation is prepared on the base of a film shaped of a poly(silyl acetylene) such as poly(1-methyl-2-trimethylsilyl acetylene) by subjecting the base film to a treatment of exposure to an atmosphere of low temperature plasma of an inorganic gas, e.g. nitrogen, hydrogen, argon, etc. Contrary to expectation, the base film is stable against the plasma treatment without decrease in the mechanical strengths and imparted with high performance for gas separation, especially, for the enrichment of oxygen in air with a separation factor between oxygen and nitrogen of 2.5 to 3.5.

Abstract: The invention provides a very efficient method with highly durable effect for preventing polymer scale deposition on the reactor walls and other surfaces coming into contact with the monomer during polymerization of an ethylenically unsaturated polymerizable monomer in an aqueous medium such as in the suspension polymerization of vinyl chloride. The method comprises coating the reactor walls, prior to polymerization, with a novel coating material which is a condensation product obtained by the condensation reaction of an aromatic amine compound such as aniline and an aromatic nitro compound such as nitrobenzene in the presence of a mineral acid and a specified condensation catalyst. It is sometimes preferable that the condensation product is basified or treated with an alkali or ammonium compound to be imparted with a modified solubility behavior.

Abstract: A continuous vacuum treating apparatus for subjecting a workpiece of soft material, such as a plastic molding to continuous surface treatment by an air-to-air system in vacuum, including a vacuum treating chamber and a plurality of auxiliary vacuum chambers located anterior and posterior to the vacuum treating chamber. The diameter of each of an upper seal roll and a lower seal roll of each of the auxiliary vacuum chambers located on the vacuum treating chamber side is smaller than the diameter of each of an upper seal roll and a lower seal roll of the auxiliary vacuum chamber located closest to the atmosphere.

Abstract: The plastic magnet composition provided by the invention comprises a thermoplastic resin as a binder and a powder of a metallic or alloy-type magnet which is coated on the particle surface with a phosphorus-containing compound having at least one phosphorus-to-oxygen linkage in a molecule such as phosphoric acid and related compounds. By virtue of the surface coating, the magnet powder is freed from the degradation by air oxidation and the danger of ignition in the molding process so that plastic magnets of high performance can be readily manufactured with safety. The advantages of the coating layer are further increased when the coating layer is formed of a combination of the phosphorus-containing compound and an organic dye compound. An overcoating on the thus coated magnet powder with an organopolysiloxane has an effect of increased lubricity.

Abstract: The invention provides a novel and improved method for the preparation of a cellular foamed body of a vinyl chloride-based resin having a very fine and uniform cellular structure with high productivity in a continuous process. According to the inventive method, a vinyl chloride-based resin is admixed with a nucleating agent and a foam conditioning resin which is a specified acrylic resin or a styrene-based resin into a resin composition and the resin composition is first heated under pressure to be converted into an at least partly gelled mass, into which a volatilizable foaming agent which is an organic solvent having a boiling point not exceeding 90.degree. C. is injected under pressure so as that the resin composition is uniformly impregnated with the foaming agent. The foaming agent-impregnated and completely gelled resin composition is then brought under a reduced pressure to be expanded into foams with simultaneous cooling.

Abstract: A novel process is proposed for the preparation of vinyl chloride based resins modified with a polymer latex, according to which the latex polymer is absorbed so completely and uniformly on the polyvinyl chloride resin that the effect of the modification of the resin properties is remarkably enhanced along with no adverse effects on the particle size distribution of the resin product and no effluence of the latex into the waste water discharged in the dehydration of the aqueous polymerizate slurry after completion of the polymerization. The process of the invention comprises introducing the modifier polymer latex into the polymerization mixture only when the monomer conversion is in the range from 30 to 95% and introducing an inorganic fine powder such as fume silica, bentonite and diatomaceous earth into the polymerization mixture at the same time as or before the introduction of the modifier polymer latex.

Abstract: The invention provides a novel method for preventing polymer scale deposition on the reactor walls in the polymerization of vinyl chloride, vinylidene chloride, styrene and other ethylenically unsaturated monomers in an aqueous medium. The inventive method comprises coating the reactor walls, piror to polymerization, with an aqueous coating solution containing a water-soluble ionic polymer and a water-soluble ionic dye having counteractive polarity to the polarity of the water-soluble ionic polymer compound. In other words, a water-soluble anionic dye is used as combined with a water-soluble cationic polymer and a water-soluble cationic dye is used as combined with a water-soluble anionic polymer compound.

Abstract: An improved method for the polymerization of vinyl chloride or a monomer mixture mainly composed of vinyl chloride in an aqueous polymerization medium is proposed in which a water-insoluble polymerization initiator, being solid at room temperature as dispersed in the aqueous medium and having a particle size distribution of 50 .mu.m or finer, is added to the polymerization mixture which is maintained at a temperature where the half-life period of the initiator is 120 minutes or longer or, alternatively, over a duration equal to or shorter than one-tenth of the half-life period of the initiator at the temperature of the polymerization mixture. By this method the polymerization can be homogeneously proceeded to produce vinyl chloride polymers having a uniform particle size distribution, excellent heat stability and much less fish-eyes when fabricated into sheets.