摘要:
A glycolic acid ester is produced by hydrogenating an oxalic acid diester of the formula, (COOR).sub.2, wherein R is a C.sub.1-6 alkyl group, with hydrogen in the presence of a solid catalyst comprising, for example, copper and silver metals carried on a solid carrier, and in the additional presence of an aliphatic alcohol, and collecting the resultant glycolic acid ester from the reaction mixture by distillation, preferably in the presence of an ester of a C.sub.3-12 dicarboxylic acid.
摘要:
A process for preparing an .alpha.-keto acid ester (oxo acid) of the formula: ##STR1## wherein R.sup.1 is a hydrogen atom, aliphatic alkyl group of 1-6 carbon atoms, phenyl group or benzyl group, and R.sup.2 is an aliphatic alkyl group of 1-6 carbon atoms, which comprises causing an .alpha.-hydroxycarboxylic acid ester of the formula: ##STR2## to react with molecular oxygen in a gaseous phase in the presence of copper phosphate, possibly, mounted on a solid carrier.
摘要:
The present invention relates to techniques including a phenolic oligomer of general formula (1): wherein n is an integer of 0 to 15, Rs are allyl groups, a1 and a3 are each independently 0, 1, 2 or 3, each a2 is independently 0, 1 or 2, each R′ is independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aryl group, and proviso that at least one of a1, each a2 and a3 represents 2, and a method for producing such phenolic oligomer.
摘要:
The elastic member for an ink jet recording apparatus according to the present invention is formed from: (1) a thermoplastic elastomer composition comprising 100 parts by weight of (a) a hydrogenated block copolymer, 60 to 170 parts by weight of (b) a softening agent for a non-aromatic rubber and 5 to 30 parts by weight of (c) polypropylene, (2) a thermoplastic elastomer composition in which a network structure having a pore diameter of 50 μm or less is formed, comprising 100 parts by weight of (a) a hydrogenated block copolymer, 60 to 170 parts by weight of (b) a softening agent for a non-aromatic rubber and 5 to 30 parts by weight of (c) crystalline polyolefin, or (3) a thermoplastic elastomer composition in which a shear rate dependency of a melt viscosity measured by means of a capillograph is −1.5 to −0.8, comprising 100 parts by weight of (a) a hydrogenated block copolymer, 60 to 170 parts by weight of (b) a softening agent for a non-aromatic rubber and 5 to 30 parts by weight of (c) crystalline polyolefin. The elastic member of the present invention is used as an ink tank valve, a sealing member for an ink tank and a sealing member for preventing an ink from leaking from a recording head.
摘要:
There are disclosed a thermoplastic elastomer composition which comprises (a) a hydrogenated block copolymer obtained by hydrogenating the block copolymer comprising at least one polymer block composed principally of a vinylic aromatic compound and at least one polymer block composed principally of a conjugated diene compound; (b) a non-aromatic base softening agent having a kinematic viscosity at 40° C. of at least 100 mm2/sec; and (c) propylene homopolymer and/or propylene copolymer comprising propylene as a principal component which is obtained through polymerization by using a metallocene catalyst, which is free from a lubricant, which has been heat treated, or which has a MFR (melt flow rate) in a specific range; a gasket material which comprises the above thermoplastic elastomer composition and is particularly suited for use in hard disc units because of its excellent sealing properties and its capability of preventing gas generation; a method for injection molding the above composition; an external anti-sticking agent for a thermoplastic elastomer or rubber which comprises fine particulates of ultrahigh molecular weight polyethylene having an average particle diameter in a specific range, and which is minimized in hygroscopicity, oil absorptivity and volatility, and has high heat resistance and anti-stickiness; and rubber and/or a thermoplastic elastomer which is incorporated with the above external anti-sticking agent and imparted with anti-stickiness.