Otsuka Chemical Co., Ltd.

Otsuka Kagaku Kabushiki Kaisha

Meiji Seika Kaisha, Ltd.

Meiji Seika Pharma Co., Ltd.

Yoichi Nishioka

Yuji Tada

Tadao Yabuhara

Shinji Nakano

Takashi Kameshima

Hiroyuki Takase

Yutaka Kameyama

Yoshifumi Nakacho

Masatoshi Taniguchi

Koichi Sorajo

Masahiro Ito

A process for preparing 7-amino-3-[(E/Z)-2-(4-methylthiazol-5-yl)vinyl]-3-cephem-4-carboxylic acid of the formula (1) and an alkali metal salt thereof, said acid and said salt being improved in the content of 7-amino-3-[(Z)-2-(4-methylthiazol-5-yl)vinyl]-3-cephem-4-carboxylic acid of the formula (2) or an alkali metal salt thereof, the process being characterized in that an aqueous solution of an alkali metal salt of 7-amino-3-[(E/Z)-2-(4-methylthiazol-5-yl)vinyl]-3-cephem-4-carboxylic acid of the formula (1) is treated with a high porous polymer and/or active carbon as added thereto. 

Process for production of 3-alkenylcephem compounds

A 3-alkenylcephem compound of the formula (1) wherein Ris benzyl or phenoxymethyl, R, Rand Rare alike or different and are each a hydrogen atom, Calkyl, Ccycloalkyl or aryl Calkyl substituted or unsubstituted with Calkyl, Rand R, when taken together, form a group &#x2014;(CH)X(CH)&#x2014; substituted or unsubstituted with Calkyl at an optional position, X is an oxygen atom or group &#x2014;N(R)&#x2014;, l is 0 to 3, m is 0 or 1, n is an integer of 2 to 4, Ris a hydrogen atom or Calkyl.

3-alkenylcephem compounds and process for production thereof

An improved phenoxyphosphazene compound is produced by treating a phenoxyphosphazene compound with (a) at least one adsorbent selected from activated carbon, silica gel, activated alumina, activated clay, synthetic zeolite and macromolecular adsorbents, (b) at least one reagent selected from metal hydrides, hydrazine, hypochlorites, thiosulfates, dialkyl sulfuric acids, ortho esters, diazoalkanes, lactones, alkanesultones, epoxy compounds and hydrogen peroxide, or (c) both the adsorbent and reagent, thereby reducing the acid value of said phosphazene compound to lower than 0.025 mgKOH/g.

Process for producing phenoxyphosphazene compound, flame-retardant resin composition, and flame-retardant resin molding

The present invention has an object to provide a flame-retardant epoxy resin composition excellent in heat resistance and moisture resistance. A flame-retardant epoxy resin composition relating to the present invention contains an epoxy resin (A), a phosphazene compound (B), an epoxy hardener (C) and an inorganic filler (D), wherein the phosphazene compound (B) and the epoxy hardener (C) are included in the range of 0.01 to 70% by weight and in the range of 0 to 70% by weight, respectively, relative to a total quantity of the epoxy resin (A), the phosphazene compound (B) and the epoxy hardener (C), and the inorganic filler (D) is included in the range of 0 to 95% by weight relative to a total quantity of the epoxy resin (A), the phosphazene compound (B), the epoxy hardener (C) and the inorganic filler (D), wherein the phosphazene compound (B) is at least one selected from the group consisting of (1) a cyclic and/or a chain phosphazene compound with a specific structure, (2) a polymer of the cyclic and/or the chain phosphazene compound; and (3) a reaction product of the cyclic and/or the chain phosphazene compound with one type of a compound selected from the group consisting of an epoxy compound, a phenol compound, an amine compound and an acid anhydride.

Flame-retardant epoxy resin composition, molded article thereof, and electronic part

A flame-retardant resin composition comprising a phosphazene flame retardant and a polyester resin, wherein the flame retardant is bonded to the molecules of the polyester resin via the ester group thereof, can retain a high flame retardance for a prolonged term with little or no vaporization with time and is excellent in flame retardance, impact resistance, properties and processability.

Flame-retardant resin, composition thereof, and process for producing the same

A powdery flame retardant which is obtained by mixing a flame retardant which is liquid or a viscous solid at ordinary temperature with an inorganic fibrous substance to adhere or adsorb the retardant to the fibrous substance, and which comprises 5 to 70 wt. % the flame retardant and 95 to 30 wt. % the fibrous substance. The powdery flame retardant can be easily handled because it is a powder, and is obtained by a simple and industrially advantageous method. It produces a remarkable effect that the performance of the liquid or viscous flame retardant is not impaired.

Powdery flame retardant

This invention has an object of providing a flame retardant which advantageously has a high melting point and a low volatility and is unlikely to depress the inherent properties of resins. The flame retardant of the invention is a phosphazene compound crosslinked with a crosslinking group such as phenylene group, each of the crosslinking groups being interposed between the two oxygen groups left after the elimination of phenyl groups from the phosphazene compound, the amount of the phenyl groups in the crosslinked compound being 50 to 99.9% based on the total number of the phenyl groups in the phosphazene compound. The invention also provides a resin composition containing the flame retardant, and a molded article of the resin.

Crosslinked phenoxyphosphazene compounds, flame retardants, flame-retardant resin compositions, and moldings of flame-retardant resins

This invention provides a halogen-free flame retardant which advantageously has a high melting point and a low volatility and does not impair the inherent properties of resins. The flame retardant of the invention is a phosphazene compound crosslinked with a crosslinking group such as a phenylene group, wherein each of the crosslinking groups is interposed between the two oxygen groups left after the elimination of phenyl groups from the phosphazene compound; the crosslinked phenoxyphosphazene compound does not have any free hydroxyl groups (derived from crosslinking groups); and the amount of the phenyl groups in the crosslinked compound is 50 to 99.9%, based on the total number of the phenyl groups in the phosphazene compound.

Crosslinked phenoxyphosphazene compounds, process for the preparation thereof, flame retardants, flame-retardant resin compositions, and moldings of flame-retardant resins

An object of this invention is to impart excellent flame retardancy to an aromatic polyamide resin without use of a halogen compound which is responsible for generation of gases harmful to the human body and without decreasing preferred properties (e.g. mechanical properties, and molding processability) inherently possessed by aromatic polyamide resins, the flame-retardant aromatic polyamide resin composition of this invention comprising (a) 100 parts by weight of an aromatic polyamide resin, (b) 0.1 to 100 parts by weight of a crosslinked phosphazene compound which is a compound crosslinked with a crosslinking group, such as phenylene groups, the crosslinking group being interposed between the two oxygen atoms left after the elimination of phenyl groups from the phosphazene compound, no free hydroxyl group being present in the molecule, the amount of all phenyl groups in the crosslinked compound being 50 to 99.9% based on the total amount of the phenyl groups in the phosphazene compounds, (c) 1 to 60 parts by weight of an inorganic fibrous substance and (d) 1 to 60 parts by weight of magnesium hydroxide.

Growing community of inventors

Tokushima, Japan

Yoichi Nishioka