摘要:
Episulfide compounds useful as starting materials of optical materials are stably stored for a long period of time at a temperature ranging from their solidifying points to 20° C., preventing the production or precipitation of polymers and the yellowing.
摘要:
A method for producing a cyclic carbamate ester produces the cyclic carbamate ester by reacting an organic compound having at least two halogen atoms per molecule, an amine having at least two hydrogen atoms on a nitrogen atom, and carbon dioxide.
摘要:
Disclosed is an acrylic syrup containing a vinyl monomer (A) of methyl methacrylate and a polymerized solid component (B) which is a high polymer of said vinyl monomer and has a weight average molecular weight of from 30,000 to 2,000,000 as measured by the GPC and a viscosity at 25° C. of from 0.1 to 50 Pa·s, wherein at least part of said polymerized solid component (B) is a grafted rubber obtained by graft-polymerizing said vinyl monomer with a rubbery polymer, and said grafted rubber has a large branching coefficient. The acrylic resin molded articles obtained from the acrylic syrup exhibit excellent impact resistance.
摘要:
There is disclosed a process for producing highly pure terephthalic acid by converting a slurry of terephthalic acid crystals in acetic acid solvent which crystals are obtained by liquid-phase oxidation of p-alkylbenzene, into a slurry thereof in water solvent by mother liquor replacement and then subjecting the latter slurry to a catalytic hydrogenation treatment which process comprises the steps of introducing the slurry of terephthalic acid crystals in acetic acid into a mother liquor replacement column at the top portion; forming an accumulation layer of the terephthalic acid crystals at the bottom portion by the sedimentation of the crystals; feeding replacing water sufficient for the formation of upward rising stream of water to the inside of the column at the bottom portion; and withdrawing the accumulation layer of the crystals from the bottom portion of the column. The accumulation layer is kept at a slightly fluidized stable state and is smoothly withdrawn from the bottom of the column by slowly rotating an arm-type agitation blade placed in the layer or by feeding the replacing water dividedly into two trains.
摘要:
A process for producing 3-methyltetrahydrofuran, wherein in a first step, prussic acid is reacted with methyl methacrylate to produce methyl 3-cyanoisobutyrate. The methyl 3-cyanoisobutyrate is then reacted with water and sulfuric acid to produce a resultant product which is reacted with a C.sub.1 -C.sub.8 aliphatic alcohol to produce a methylsuccinic acid ester. The methylsuccinic acid ester is catalytically hydrogenated to prepare the 3-methyltetrahydrofuran. Alternatively, the methyl 3-cyanoisobutyrate is hydrated to produce methyl 3-carbamoylisobutyrate, which is then reacted with a formic acid ester to form a methylsuccinic acid ester and formamide and the resultant methylsuccinic acid ester is catalytically hydrogenated. The 3-methyltetrahydrofuran is produced in high selectivity and in a commercially advantageous manner from inexpensive reactants. The 3-methyltetrahydrofuran is useful as a commoner for producing polyether glycol, which is utilized as starting raw material for preparing spandex fiber.
摘要:
Proposed is an improvement in a method for the preparation of an enriched and purified aqueous hydrogen peroxide solution from a crude aqueous hydrogen peroxide solution comprising the steps of evaporating the crude aqueous hydrogen peroxide solution in an evaporator into vapor with accompanying liquid in the form of a mist, separating the vapor from the mist of liquid in a gas-liquid separator and subjecting the vapor to fractionating distillation in a fractionating distillation column in order to greatly upgrade the product solution relative to the impurity content. The improvement is achieved by subjecting the crude aqueous hydrogen peroxide solution, prior to introduction into the evaporator, to a contacting treatment with a porous synthetic adsorbent resin to remove organic impurities from the crude aqueous hydrogen peroxide solution to such an extent that the crude aqueous hydrogen peroxide solution after the contacting treatment contains organic impurities in an amount not exceeding 50 ppm by weight calculated as organic carbon. Although the mechanism is not well understood, the preliminary removal of organic impurities from the crude aqueous hydrogen peroxide solution has an effect of greatly increasing the efficiency of gas-liquid separation of the vapor accompanied by a mist of liquid in the gas-liquid separator to decrease the amount of contaminant impurities introduced into the distillation column as carried by the mist.
摘要:
A process for producing a resin molded article having a diminished residual stress, which includes heating an injection-molded article of a thermoplastic resin by means of a combination of far infrared radiation with far infrared ray having a frequency of from 10.sup.11 to 10.sup.14 Hz and hot-air flow, thereby to diminish a residual stress in the molded article in a short period of time.
摘要:
A process for producing a multilayered printed circuit board which comprises using, as an intermediate layer, an inner-layer board obtained by chemically oxidizing the surface of a copper foil constituting an outermost layer of an inner-layer board having a printed circuit formed in the copper foil, thereby to form on the surface a finely roughened layer constituted by a copper oxide of a brown to black color, and then reducing the copper oxide constituting the finely roughened layer in an atmosphere in which a reducing gas is present.
摘要:
A fiber-reinforced resin composition having surface smoothness, which comprises(1) 100 parts by weight of a thermoplastic resin composition comprising an aromatic polycarbonate resin and a thermoplastic polyester resin in a weight ratio of from 10/90 to 90/10,(2) from 50 to 100 parts by weight of glass fiber sheet chips having an almost rectangular shape, each side having a length of from 1 to 30 mm, the glass fiber sheet chips being obtained by forming E-glass fibers having an average fiber diameter of 2 .mu.m or less which have been surface-treated with a silane coupling agent, into a sheet by a paper making process and then cutting the resulting sheet, and(3) from 0 to 40 parts by weight of a thermoplastic elastomeric polymer,and an exterior automotive part showing excellent image clarity, obtained by shaping the fiber-reinforced resin composition.
摘要:
A method and an apparatus for applying a freshness keeping agent to a food packaging body arranged to comprise: a step in which a hot-melt adhesive agent is, at a predetermined interval, dripped on to the inner surface of a wrapping film which is being continuously supplied; a step in which an elongated train consisting of a plurality of freshness keeping agent bags successively connected in a direction and continuously supplied is cut into individual freshness keeping agent bags; a step in which each freshness keeping agent bag is conveyed to the wrapping film through a chute; and a step in which either side of each freshness keeping agent bag and the inner surface of the wrapping film are joined to each other under pressure at a portion to which the hot-melt adhesive agent is applied.