Asahi Kasei Kogyo Kabushiki Kaisha

Asahi Kasei Kabushiki Kaisha

Asahi Kasei Chemicals Corporation

Tsutomu Katsumata

Tetsuro Dozono

Makoto Honda

Kunitoshi Aoki

Hitoshi Nakajima

Akinori Yokoyama

Nobuhisa Miyake

Hiroshi Yokoyama

Katsuhiro Fujimoto

Hideo Kasahara

Setsuo Yamamatsu

Tamotsu Kodama

Masahisa Yokota

Kiyoshi Kawakami

Muneaki Aminaka

Hiroyuki Ohashi

Eiji Ueda

Haruyuki Minoura

Kazuhiro Matsubara

Junichi Sugimoto

The present invention provides a method of producing polyalkylene terephthalate, which comprises: introducing a prepolymer of polyalkylene terephthalate that is in a molten state comprising 70 mol % or more of ethylene terephthalate or 1,4-butylene terephthalate repeating units and having an intrinsic viscosity [&#x3b7;] between 0.2 and 2 dl/g through a feed opening to a polymerization reactor; discharging the introduced prepolymer from holes of a perforated plate; and polymerizing the prepolymer under reduced pressure, while allowing the prepolymer to fall along the surface of a support that is open towards the outside at a temperature between the [crystalline melting point&#x2212;10&#xb0; C.] of the prepolymer or higher and the [crystalline melting point+30&#xb0; C.] of the prepolymer or lower under the conditions represented by a formula S/S&#x3e;1, wherein Sis the surface area of falling polyalkylene terephthalate, and Sis the area where the support is in contact with polyalkylene terephthalate.

Process for producing polyalkylene terephthalate, process for producing polyalkylene terephthalate molding and polyalkylene terephthalate molding

Process for the preparation of acylated hexaazaisowurtzitane derivatives

Flame-retardant resin composition

Copper alloy compositions

High temperature baking paste

Methacrylonitrile higher in purity than that obtained by the conventional process is efficiently produced by the present improved process for producing purified methacrylonitrile in which the reaction mixture formed by the ammoxidation of isobutylene or tert-butyl alcohol is distilled using water as solvent to obtain a crude methacrylonitrile solution which contains methacrylonitrile as major constituent, methacrolein, hydrogen cyanide, and isobutyronitrile, and the crude methacrylonitrile solution is then purified in a product column, wherein the improvement comprises first removing isobutyronitrile from said crude solution, then feeding the remaining solution to the product column, withdrawing from the top a vapor containing methacrolein, condensing the vapor, returning a greater part of the condensate to the product column while removing the remainder from the distillation system, and withdrawing purified methacrylonitrile from the middle or lower section, preferably from a point lower than the feeding stage.

Recovery process for producing purified methacrylonitrile

In the preparation of methacrylonitrile by gas-phase ammoxidation of isobutylene or tertiary butanol, the reaction is carried out (A) (i) using a catalyst system consisting essentially of (1) 30-70% by weight of a silica catalyst carrier and (2) a catalyst material having a composition represented by the formula:

Production of methacrylonitrile

By flowing a gaseous stream containing methanol and a phenol through a fluidized bed of particles of a highly attrition resistant catalyst comprising 10 to 80% by weight of silica and 90 to 20% by weight of a metal oxide supported on the silica and have been calcined at 500.degree. to 900.degree. C., the ortho position of the phenol is methylated with high selectivity, whereby various useful ortho-methylated phenol derivatives can be advantageously obtained.

Process for methylating the ortho position of a phenol

Malononitrile is prepared in a high yield by catalytic oxidative dehydrogenation of .beta.-aminopropionitrile in a gaseous phase with molecular oxygen in the presence of a catalyst, comprising a oxide composition of, preferably, Mo and at least one other catalytic element, more preferably, of the empirical formula (I):

Process for producing malononitrile

A catalyst composition having a composition represented by the formula:

Catalyst composition

A process for the preparation of acrylonitrile by the ammoxidation reaction of propylene, characterized by using an oxide type catalyst which contains, as active ingredients, molybdenum, bismuth, iron and at least one element selected from potassium, rubidium and cesium in specifically limited proportions and which may further contain sodium and/or phosphorus. By the use of such a specific catalyst, the selectivity for the desired acrylonitrile is remarkably improved, and there can be attained high yield of the product. In the process of the present invention, the catalyst can maintain a high activity and a high selectivity for a long time, without undergoing attrition. The catalyst is well prevented from sublimation-escaping of the ingredient molybdenum therefrom.

Process for the preparation of acrylonitrile

Growing community of inventors

Yokohama, Japan

Tsutomu Katsumata