摘要:
Acrylic multilayer polymer powders containing coagulated powders of emulsified latexes of acrylic multilayer polymers, which are suitable for drying methods using pressure dehydration extruders, etc, comprises not more than 40 wt % of a fine powder of a particle size of 212 .mu.m or less after drying, and have a volume of gaps of a pore size of 5 .mu.m or less after drying of not more than 0.7 cc per unit weight as measured by a mercurial pressure method. A desired monomer is subjected to emulsion polymerization to produce an emulsified latex of an acrylic multilayer polymer, which is then poured into a coagulating solution for coagulation.
摘要:
A multilayered acrylic polymer comprising an innermost layer polymer (A) formed from a C1-4 alkyl methacrylate, a C1-8 alkyl acrylate, etc., an intermediate layer polymer (B) formed from a C1-8 alkyl acrylate, an aromatic vinyl monomer, etc., and an outermost layer polymer (C) formed from a C1-4 alkyl methacrylate, a C1-8 alkyl acrylate, etc., and wherein the average value of the coating ratio, i.e. [(minimum thickness of the intermediate layer)÷(maximum thickness of the intermediate layer)]×100, is not less than 30%; and a methacrylic resin composition containing the same. This multilayered acrylic polymer can improve the falling-ball or falling-weight impact strength, resistance to impact whitening, transparency and other properties of the methacrylic resin composition.
摘要:
Disclosed are polyacrylonitrile carbon fibers excellent in substrate strength and adhesion to matrix resin wherein average nitrogen content in the whole carbon fibers which is measured by elementary analysis is 0.5-4.5% by weight and average nitrogen concentration (N/C atom number ratio) in the whole carbon fibers which is measured by elementary analysis and surface silicon concentration (Si.sub.2p /C.sub.1s atom number ratio), surface nitrogen concentration (N.sub.1s /C.sub.1s atom number ratio) and surface oxygen concentration (O.sub.1s /C.sub.1s atom number ratio) which are measured by X-ray photoelectron spectroscopy satisfy the following formulas:0.ltoreq.Si.sub.2p /C.sub.1s .ltoreq.0.020.67 N/C+0.08.ltoreq.O.sub.1s /C.sub.1s -2 Si.sub.2p /C.sub.1s .ltoreq.0.40.ltoreq.N.sub.1s /C.sub.1s -N/C.ltoreq.0.04and method for producing the carbon fibers.
摘要:
A process for surface treatment of carbon fiber of which modulus is not lower than 30 ton/mm.sup.2, in two steps, which comprises the steps of subjecting a carbon fiber as an anode to a first electrolytic treatment in an aqueous solution of inorganic acidic electrolyte or of neutral salt electrolyte, and then subjecting the treated fiber to a second electrolytic treatment in an aqueous solution of ammonium salt of carbonic acid or of inorganic alkaline electrolyte.