Abstract: Provided is a rear projection screen of a certain configuration having an entrance surface receiving red, blue and green rays from projectors on a projecting side and formed therein entrance lenses and an exit surface allowing images synthesized or merged with the red, blue and green light rays to be observed on a viewing side and formed therein exit lenses corresponding respectively to the incident lenses, each of the entrance lenses are each of the exit lenses having optical axes and lens surfaces around the optical axes, respectively, with theoretical curvatures so that each entrance lens transmits red, blue and green light rays to the corresponding exit lens while the entrance lens converges the light rays into a certain converging area around the cross point between the lens surface of the corresponding exit lens and the optical axis if the configuration of the screen is theoretical, and each associated exit lens emits the converged light rays from the exit surface toward the viewing side over a predeter

Abstract: Disclosed is a porous membrane consisting of a film-forming polymer characterized in that:(a) in at least one surface thereof, pores extending in a direction substantially perpendicular to the membrane surface are present at a surface pore density of 20 to 80%, said pores having an average pore diameter within the range of 0.01 to 100 .mu.m, a ratio of major to minor axis within the range of 1.0 to 2.0, and a coefficient of variation of pore diameter within the range of 0 to 50%; and(b) the overall porosity of said porous membrane is within the range of 20 to 90%.

Abstract: An automatic gain control circuit comprising an input terminal means for receiving first and second signals, an amplifier for receiving and amplifying first and second signals and outputting a first output signal when receives the first signal and outputting a second output signal when receives the second signals, input means for receiving an operation control signal and responsive to the operation control signal for separately inputting the first and second signals to the amplifier with a predetermined interval of time, control signal generating means responsive to the second output signal of the amplifier for generating a control signal, selection means connected to the input means for supplying the second output signal of the amplifier to the control signal generating means when the second signal is fed to the amplifier and sending out the first output signals to an external circuit when the first signal is fed to the amplifier and gain control means connected to the amplifier and the control signal genera

Abstract: Disclosed is a graft copolymer resin prepared by graft polymerizing a vinyl compound onto a composite-structured acrylic rubber whose particles are composed of a core consisting of a diene rubber enlarged by treatment with an acid group-containing copolymer latex, and an outer layer consisting of an acrylate polymer having a crosslinked structure formed by the combined use of a graft-linking agent and a cross-linking agent. This graft copolymer resin may be blended with a rigid thermoplastic resin in a specific proportion. This resin composition imparts a good gloss to the molded articles formed therefrom, while retaining excellent impact resistance and weather resistance.

Abstract: A method for preparing a polymeric composition in which an inorganic compound is firmly consolidated in an organic polymer, which comprises polymerizing at least one radical polymerizable vinyl monomer in an aqueous medium polymerization system comprising an inorganic compound dispersed in the presence of an organic acid monomer or organic acid salt monomer, by using a radical polymerization initiator.

Abstract: A reinforced resin composition which comprises 50-95% by weight of polyglutarimide resin and 5-50% by weight of carbon fibers.The polyglutarimide resin is one containing imide units of 2% by weight or more, represented by the formula, ##STR1## wherein R stands for hydrogen atom or an aliphatic, aromatic or alicyclic hydrocarbon group having 1 to 20 carbon atom(s).

Abstract: A resin composition suitable for various optical uses, which comprises a base resin and 0.1 to 60% based on the weight of said resin composition, of fine silica or glass particles, said fine silica or glass particles having an average particle diameter of 0.05 to 50 .mu.m and having their surface treated with at least one silane compound selected from those represented by the following general formulae (I) to (IV): ##STR1## wherein n is an integer of from 1 to 3, R.sup.1 is an alkyl group having 1 to 3 carbon atoms, and R is a saturated or unsaturated hydrocarbon group having 1 to 22 carbon atoms or a halogen-substituted, saturated or unsaturated hydrocarbon group having 1 to 22 carbon atoms, wherien the silane does not couple the particle and the resin.

Abstract: N-substituted maleimides are prepared by reacting maleic anhydride with an amine in the presence of Cu or a copper compound and purifying the maleimide produced in the absence of presence of said Cu or copper compound. N-substituted maleimides are widely useful or starting materials or intermediates for medicines, agricultural chemicals, dyes, macromolecular compounds, and the like.

Abstract: An active-energy-ray curable coating composition comprising 99 to 50 parts by weight of an acrylic copolymer (A) having (meth)acryloyloxy groups linked to functional groups of side chains and 1 to 50 parts by weight of an unsaturated compound (B) having two or more crosslinkable bonds.

Abstract: A polymethacrylimide resin composition having an improved impact resistance and thermal resistance is prepared by blending a polymethacrylimide resin with a polyorganosiloxane type graft copolymer formed by graft-polymerizing at least one ethylenically unsaturated monomer onto a polyorganosiloxane rubber copolymerized with a graft-crosslinking agent.

Abstract: A process for producing an acrylic fiber comprising the steps of:(a) dissolving a polymer having a weight-average molecular weight of at least 5.times.10.sup.5 and containing at least 80 wt. % acrylonitrile in a solvent comprising dimethylformamide or dimethylacetamide at a polymer concentration of 5-15 wt. % to provide a spinning solution having a viscosity of 500-1,500 poises at 45.degree. C.;(b) extruding the solution into a gaseous medium to form filaments;(c) introducing the filaments into a coagulation bath comprising water and at least one of dimethylformamide and dimethylacetamide at 0.degree. C. or below; and(d) stretching the coagulated filaments to a draw ratio of at least 3 to provide an acrylic fiber having at least 90% X-ray orientation and an X-ray crystallinity parameter of up to 1 degree. The resulting acrylic fiber has high strength and high modulus.

Abstract: There is disclosed a thermoplastic resin composition comprising a polyether imide resin (A) and an aromatic polyester-polyorganosiloxane block copolymer (B), the weight ratio of A to B (A/B) being 1/9 to 9/1.

Abstract: An aromatic polyester-polyorganosiloxane block copolymer comprising a polyester segment consisting essentially of:(a) an aromatic polyester of an aromatic dicarboxylic acid, or mixtures thereof, and a dihydric phenol, a lower aliphatic diol, an alicyclic diol, or mixtures thereof,(b) an aromatic polyester of an aromatic hydroxycarboxylic acid or mixtures thereof, or(c) a copolymer of (a) and (b),and a polyorganosiloxane segment having a recurring unit represented by the formula: ##STR1## in which R.sub.1 represents a lower alkylene group or a lower alkylene ether group; R.sub.2 and R.sub.3 independently represent a methyl group or a phenyl group; and n represents an integer not smaller than 10, in which bonding between the polyester segment and the polyorganosiloxane segment is an ester linkage formed by a condensation reaction between the terminal carboxyl group of the polyester segment and the terminal hydroxyl group of the polyorganosiloxane segment.

Abstract: A polyphenylene ether resin composition comprising(A) a polyphenylene ether resin,(B) a polystyrene resin, and(C) a graft copolymerprepared by graft-polymerizing one or more vinyl monomers onto a compound rubber having an average particle diameter of 0.08 to 0.6 .mu.m and a structure wherein 10 to 90% by weight of a polyorganosiloxane rubber component and 90 to 10% by weight of a polyalkyl (meth)acrylate rubber component are tangled with each other so as not to separate, the total amount of the polyorganosiloxane rubber component and the polyalkyl (meth)acrylate rubber component being 100% by weight of the compound rubber. This resin composition provides molded products superior in impact resistance, heat resistance, mechanical strength, and surface appearance and is superior in moldability and flow properties.

Abstract: A polyphenylene ether resin composition superior in impact resistance, heat resistance, mechanical strength, moldability, and flow properties, comprising a polyphenylene ether resin (A), a polystyrene resin (B), and a polyorganosiloxane-based graft copolymer (C) produced by graft polymerizing one or more vinyl monomers onto a polyorganosiloxane rubber which contains a graft-linking agent copolymerized and exhibits a degree of swelling of 3 to 15 measured in toluene.

Abstract: The present invention provides a process for the preparation of a catalyst used in the production of unsaturated carboxylic acids such as methacrylic acid by the gas phase catalytic oxidation of the corresponding unsaturated aldehydes such as methacrolein. Said catalyst is composed of a multi-component composition containing at least phosphorus, molybdenum and antimony. The present invention has attained an improved in its catalytic performance such as conversion rate, selectivity, single-pass yield etc. by using antimony trioxide with average particle size of no more than 0.2 micron as a starting material upon preparing said catalyst.

Abstract: A process for producing a cellulose acetate molding material which comprises dissolving cellulose diacetate in a mixed solvent of acetone and water to prepare a dope and then spinning or film forming the dope, wherein at least one compound selected from the group consisting of water-soluble salts and bases is added to the water to be used in preparation of the dope.

Abstract: High molecular weight hyaluronic acid can be efficiently produced by incorporating one or more compounds having at least one aromatic ring to which one or more hydroxyl groups are attached into a medium for producing hyaluronic acid by a bacterium capable of producing hyaluronic acid. By using this method, a sufficient amount of hyaluronic acid can be easily obtained without decomposing the high molecular structure of hyaluronic acid so that the process for isolating and purifying hyaluronic acid from the medium can be simplified.

Abstract: Disclosed is a method for producing a rubber modified thermoplastic resin which comprises carrying out all or a part of the following steps (I)-(VI):(I) a setp of mixing the following (A), (B), (C) and thermoplastic resin (2):(A) a latex of gfart rubber polymer (1),(B) an organic agent which is capable of dissolving thermoplastic resin (2) and has a solubility in water of 5% by weight or less t a temperature at which (A), (B), (C) and thermoplastic resin (2) are mixed, amount of the organic agent being 10-600% by weight of polymer (4) which is the sum of graft rubber polymer (1) and thermoplastic resin (2) and(C) a warer soluble agent capable of coagulating latex (A), amount of this agent being 10% by weight or less of graft rubber polymer (1),(II) a step of separating and removing aqueous phase from a two-phase mixture obtained in the mixing step (I),(III) a step of mixing the mixture from which the aqueous phase hsa been removed at step (II) and the whole or a part of thermoplastic resin (3),(IV) a step of

Abstract: A polycarbonate resin composition excellent in chemical resistance, weather resistance, heat resistance, and low-temperature impact resistance, which comprises,either a polycarbonate resin (A) or a mixture (A') of the polycarbonate resin and a saturated polyester and/or a polyester elastomer andeither a siloxane based graft copolymer (B) obtained by graft polymerization of 95 to 10% by weight of at least one vinyl monomer onto 5 to 90% by weight of a polyorganosiloxane rubber which exhibits a degree of swelling of 3 to 30 as measured to toluene at 25.degree. C., contains constitutional units derived from a graft-linking agent, and has an average particle size of 0.08 to 0.8 .mu.m or a mixture (B) of the siloxane-based graft copolymer and a vinyl polymer,wherein the component (B) is blended so that the content of the polyorganosiloxane rubber may be from 0.5 to 60% by weight based on the whole resin composition.