Gun Ei Chemical Industry Co., Ltd.

Kurita Water Industries Ltd.

Shin-etsu Chemical Co., Ltd.

Nippon Kayaku Kabushiki Kaisha

Gun Ei Cheical Industry Co., Ltd.

Meinan Machinery Works, Inc.

Yukio Abe

Yoshiaki Kurimoto

Akiyuki Kojima

Satoru Kitano

Tsuyoshi Fukuda

Kaori Hasegawa

Tsutomu Ogihara

Seiichiro Tachibana

Daisuke Kori

Satoshi Wada

Noriyuki Honda

Makoto Isobe

Ryoichi Hasegawa

Kenichi Kuboki

Hiroshige Oda

Akihito Hamaguchi

Issaku Okamura

Yoshio Shimamura

Michiyasu Yamazaki

Chigusa Taguchi

Keijirou Tada

Taiki Kobayashi

Yuko Okusa

Youhei Umino

Fumihiro Hatakeyama

Yasuhiro Ooi

Takeshi Iizuka

The invention provides: a dihydroxynaphthalene condensate which suppresses soft particle generation and is suitably usable for a composition excellent in filterability; and a method for producing the dihydroxynaphthalene condensate. In the method for producing a dihydroxynaphthalene condensate, dihydroxynaphthalene to be used has a sulfur element content of 100 ppm or less in terms of mass among constituent elements. The dihydroxynaphthalene and a condensation agent are condensed in presence of an acid or a base to produce the dihydroxynaphthalene condensate.

Method for producing dihydroxynaphthalene condensate and dihydroxynaphthalene condensate

Provided are a pitch-formation suppressor and the like which can be widely applied independently of the substance that causes a pitch and of the situation to generate a pitch in a paper manufacturing process, and which can effectively suppress and prevent the troubles due to the pitch, such as foreign spots and defects in a paper, breakage of a paper, and lowering of workability. This pitch-formation suppressor comprises an alkaline solution in which a phenol resin and/or a modified phenol resin is dissolved, or an acid solution in which a phenol resin and/or a modified phenol resin is dissolved.

Method for suppressing pitch formation

A curable resin including a repeating unit of hydroxystyrene substituted with an alkoxymethyl group, the repeating unit represented by the following general formula (1): where Ra represents a hydrogen atom or a methyl group; Rb represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; m is 1 to 3; and n is 1 to 3.

Curable resin, method of producing the same, and cured product

There is provided a water treatment method using a water treatment flocculant that suffers from minimal secondary contamination with flocculation residues and contains an alkaline solution of a phenolic resin. A water treatment method involving the addition of a flocculant to water to be treated and subsequent membrane separation treatment. The flocculant contains an alkaline solution of a phenolic resin having a melting point in the range of 130&#xb0; C. to 220&#xb0; C. The water treatment flocculant is produced by a resole-type second-order reaction in the presence of an alkaline catalyst in which an aldehyde is added to an alkali solution of a novolak phenolic resin. The novolak phenolic resin is produced by a reaction between a phenol and an aldehyde in the presence of an acid catalyst.

Water treatment method and water treatment flocculant

Epoxy resin, epoxy resin composition and hardened product thereof

One of the objects of the present invention is to offer novolak type phenolic resins which use phenols and aldehydes as raw materials and give narrow molecular weight distributions. The novolak type phenolic resins of the present invention are those obtained by condensation reaction of phenols with aldehydes in the presence of an oxycarboxylic acid having carboxyl groups, --COOH, and alcoholic hydroxyl groups, --OH, in one molecule. Thus obtained novolak type phenolic resins show narrow molecular weight distributions, lower viscosity in molten state and, as a consequence, uniformity in curing time.

Novolak type phenolic resins and methods of manufacturing thereof

One of the objects of the present invention is to offer novolak type phenolic resins which use phenols and aldehydes as raw materials and give narrow molecular weight distributions. The novolak type phenolic resins of the present invention are those obtained by condensation reaction of phenols with aldehydes in the presence of an oxycarboxylic acid having carboxyl groups, --COOH, and alcoholic hydroxyl groups, --OH, in one molecule. Thus, obtained novolak type phenolic resins show narrow molecular weight distributions, lower viscosity in molten state and, as a consequence, uniformity in curing time.

Growing community of inventors

Takasaki, Japan

Yukio Abe