Abstract: Provided are a method for producing a crystalline methacrylic resin, the method comprising a step of bringing a mixture of an isotactic methyl methacrylate-type polymer and a syndiotactic methyl methacrylate-type polymer into contact with high pressure gas and a method for producing a plastic foam of the crystalline methacrylic resin, the method comprising a step of foaming the mixture. According to the method of the present invention, a crystalline methacrylic resin which is not limited in a form applicable to molded articles thereof and has high crystallinity and excellent solvent resistance can be obtained in a simple method and a plastic foam of the crystalline methacrylic resin can be obtained, the plastic foam embracing fine cells having an average cell diameter of about 10 &mgr;m or less and a cell number density of 109 to 1015 cells/cm3. Such a plastic foam is superior in the solvent resistance and in the mechanical properties such as impact resistance and bending strength.

Abstract: Disclosed is a process for producing a methacrylate polymer, wherein a monomer feed composed of methyl methacrylate or a mixture of at least 70 weight % of methyl methacrylate and not more than 30 weight % of one or more vinyl monomers copolymerizable with methyl methacrylate is continuously bulk polymerized in a substantially perfect mixing state to give a polymer composition having a polymer content of 40-70% by weight in a continuous manner, which comprises carrying out the bulk polymerization in the reactor which is filled up with the polymer composition leaving substantially no gas phase therein and which is maintained in a thermally insulated state allowing substantially no exchange of heat with the external environment at a polymerization temperature of 120.degree.-180.degree. C.

Abstract: An optical device comprising a mixture of a polymer constituted mainly of aromatic vinyl monomer units and polyphenylene ether, characterized in that the average molecular weight of the polyphenylene ether is from 0.3 to 0.7 expressed in terms of the intrinsic viscosity measured in chloroform at 25.degree. C.

Abstract: A coating composition is disclosed which includes(A) 15 to 65% by weight (calculated as SiO.sub.2) of colloidal silica,a partially hydrolyzed and partially co-condensed product of the following component (B) and component (C):(B) 10 to 80% by weight (calculated as R.sup.1 Si(OH).sub.3) of a trialkoxysilane of the formula: R.sup.1 Si(OR.sup.2).sub.3 wherein the group R.sup.1 is methyl or vinyl and the group R.sup.2 is alkyl having 1 to 4 carbon atoms,(C) 1 to 50% by weight (calculated as R.sup.3.sub.n Si(OH).sub.4-n) of an acetoxysilane of the formula: R.sup.3.sub.n Si(OCOCH.sub.3).sub.4-n wherein the group R.sup.3 is alkyl having 1 to 3 carbon atoms, vinyl, phenyl, or mercaptoalkyl having 1 to 3 carbon atoms, and n is an integer of 0 to 2, provided that the total amount of the component (B) wherein the group R.sup.1 is methyl and the component (C) wherein the group R.sup.

Abstract: A process for the production of formed articles of aromatic vinyl resin having a small birefringence and a high refractive index by a cast polymerization process rapidly and with high productivity, wherein the formed articles of aromatic vinyl resin are light and useful for the production of various optical elements such as lenses and prisms.

Abstract: An unsaturated compound having a vinyl or vinylidene group is rapidly in-mold polymerized by mixing the unsaturated compound containing a polymerization initiator and the unsaturated compound containing a polymerization accelerator, pouring the mixture into a mold cavity and polymerizing the monomer for not longer than 30 minutes.

Abstract: Improved method for the production of a polymer of a monofunctional (unsaturated) monomer, particularly polymethyl methacrylate, by a rapid crosslinking polymerization, which comprises polymerizing a mixture of a monofunctional (unsaturated) monomers, selected from methyl methacrylate and a monomer mixture comprising predominantly methyl methacrylate which may partially contain a polymer of the monomer (i.e. a syrup of the monomer or monomer mixture), and a polyfunctional (unsaturated) monomer in the presence of (1) a radical polymerization initiator, (2) a reducing compound containing sulfur in the molecule thereof, (3) an amine hydrohalogenate or a quaternary ammonium halide and (4) a copper-containing compound. Said polymer has high mechanical properties and excellent transparency and is useful particularly for the production of optical parts such as conventional lenses, Fresnel's lens, optical recording disc media, prisms, mirrors, etc.

Abstract: Improved method for the production of polymethacrylates by a rapid polymerization, which comprises polymerizing an unsaturated monomer selected from a methacrylate and a monomer mixture comprising predominantly a methacrylate which may partially contain a polymer of the monomer (i.e. a syrup of the monomer or monomer mixture) in the presence of a radical polymerization initiator, a reducing compound containing sulfur in the molecule thereof, a copper-containing compound and a specific tertiary amine hydrohalogenate or a quaternary ammonium halide. Said polymethacrylates can give molded products having excellent mold release characteristics and are useful particularly for the production of optical parts such as conventional lenses, Fresnel's lens, optical recording disc media, prisms, mirrors, etc.

Abstract: A process for the production of a thermoplastic copolymer having excellent heat distortion resistance is disclosed. The process includes heat-treating a raw copolymer comprising a vinyl monomer unit including methacrylic and/or acrylic acid units in the presence of a specific ring-closing promoter selected from basic compounds, whereby the methacrylic and/or acrylic acid unit is converted into six-membered cyclic anhydride unit. The copolymer has excellent heat distortion resistance, transparency, mechanical properties and processability, and can produce a formed product without splash on the surface. The copolymer is useful for the production of various parts, such as automobile parts, electrical parts, industrial parts, and miscellaneous goods.

Abstract: A polymerization can be carried out rapidly by polymerizing a methacrylate ester or a mixture of unsaturated monomers comprising the methacrylate ester as a main component in the presence of (1) a hydroperoxide polymerization initiator, (2) a reductant containing sulfur in a molecule, (3) a hydrogen halogenide salt of amine or a quarternary halogenide and (4) a copper-containing compound.

Abstract: An acrylic resin composition having excellent permanent antistatic properties, which comprises a copolymer of an acrylic monomer comprising predominantly methyl methacrylate with a specific sulfonate and optionally a specific alkylene oxide and/or acidic phosphate, and a method for the production thereof. The acrylic resin composition of the invention shows excellent antistatic properties without losing the excellent properties of methacrylic resin, such as excellent transparency, mechanical properties, heat resistance, etc., and is useful for various utilities, such as preparation of advertising display, lighting fixtures, covers, nameplate, and various decoratings.

Abstract: An improved process for the production of a methacrylic polymer having excellent heat resistance, which comprises radical-polymerizing a monomer or monomer mixture consisting of 80 to 100% by weight of methyl methacrylate and 0 to 20% by weight of a copolymerizable vinyl monomer in the presence of a polymerization initiator and one or more of specific chain transfer agents selected from the group consisting of(A) 2-mercaptoethyl alkanecarboxylate of the formula: ##STR1## wherein R is an alkyl having 4 to 12 carbon atoms,(B) alkyl 3-mercaptopropionate of the formula: ##STR2## wherein R is an alkyl having 4 to 18 atoms. The methacrylic resin prepared by this invention has excellent heat resistance and can give formed products having excellent heat resistance (high heat distortion temperature) without increase of monomer content processing thereof.

Abstract: An acrylic resin composition having excellent permanent antistatic properties, which comprises a copolymer of an acrylic monomer comprising predominantly methyl methacrylate with a specific sulfonate and optionally a specific alkylene oxide and/or acidic phosphate, and a method for the production thereof. The acrylic resin composition of the invention shows excellent antistatic properties without losing the excellent properties of methacrylic resin, such as excellent transparency, mechanical properties, heat resistance, etc., and is useful for various utilities, such as preparation of advertising displays, lighting fixtures, covers, nameplates, and various decorations.

Abstract: A process for producing glass fiber-reinforced, transparent cast sheets comprising impregnating glass fibers with a resin syrup comprising 10 to 50 parts by weight of a copolymer (A) consisting essentially of 20 to 95% by weight of an aromatic vinyl compound and 5 to 80% by weight of other polymerizable monomer, 1 to 40 parts by weight of an aromatic vinyl compound (B), 50 to 90 parts by weight of other polymerizable monomer (C) and optionally 0.5 to 10 parts by weight of maleic anhydride, and casting the resulting mixture.

Abstract: A continuous process for producing rubber-modified methyl methacrylate syrups which comprises continuously supplying a material liquor comprising 1 to 20 parts by weight of a rubbery polymer dissolved in 100 parts by weight of a monomer comprising 60 to 100% by weight of methyl methacrylate, and a radical-polymerization initiator to the first reaction zone, continuously polymerizing at such a stationary conversion that the rubber polymer is dispersed in the form of particles form while maintaining the temperature and residence time in the zone so that a steady state is achieved in the zone and the steady-state concentration of the initiator in the zone is 1/2 to 1/1,000 time as much as the concentration of initiator supplied, continuously taking out the resulting reaction mixture from the zone, and passing it through the second reaction zone having a volume of 0 to 5 times as much as that of the first reaction zone, to obtain a stable syrup comprising a disperse phase and a continuous phase, the former phase

Abstract: A continuous process for producing plate-like polymer articles which comprises subjecting a liquid polymerizable composition comprising a syrup of methyl methacrylate and a specified amount of a polymerization initiator of the formula: ##STR1## (in which R is a C.sub.4 -C.sub.10 alkyl or alkoxyalkyl group), to a casting polymerization at a specified temperature. By this process, plate-like polymer articles having a high quality can be obtained in a very short polymerization time.

Abstract: A process and apparatus for the continuous casting of a liquid polymerizable composition comprising feeding the liquid polymerizable composition together with a pair of continuous gaskets into a spacing between a pair of moving endless belts arranged such that the lower run of the upper belt is disposed above the upper run of the lower belt and said runs are driven concurrently in the same direction at substantially the same speed, said gaskets being fed such that they circumscribe both side end portions of the spacing to form a cavity, while moving together with the moving belts and keeping in contact with the opposing surfaces of the belts.

Abstract: A continuous casting process and apparatus for a liquid polymerizable composition comprising a pair of endless belts which are arranged such that the lower run of the upper belt is disposed above the upper run of the lower belt and said runs are caused to move in the same direction at substantially the same speed; feeding a liquid polymerizable composition into a space defined between said runs; feeding at least one continuous gasket into said space, together with said composition, in such a manner that said gasket is passed between and in contact with the opposing surfaces of each of the opposite edges of said belts to provide a pair of seals which circumscribe said edges of the moving belts; subjecting said composition to partial polymerization to such an extent that the viscosity of said composition in terms of poise is within the range of 2 to 5 determined by a common logarithm of said viscosity at the temperature of polymerization; leading said partially polymerized composition in a path which is arrange