Kureha Kagaku Kogyo Kabushiki Kaisha

Kureha Kagaku Kogyo K.k.

Kureha Corporation

Kureha Chemical Industry Company, Limited

Kureha Kagaku Kagyo K.k.

Kureha Kagaku Kogho K.k.

Toshiya Mizuno

Takayuki Katto

Ken Kashiwadate

Yoshikichi Teramoto

Yoshikatsu Satake

Zenya Shiiki

Shinji Yamamoto

Takashi Kaneko

Masahito Tada

Hiroyuki Endo

Juichi Wakabayashi

Takeshi Saito

Yo Iizuka

Naohiro Murayama

Yasuhiro Tada

Seiichi Ohira

Takeo Takahashi

Toshio Hosokawa

Shunzo Endo

Kazuyuki Munakata

Masayuki Hino

Hideyuki Yasumi

Kenichi Katase

Kenichi Suzuki

Toshitaka Kouyama

Satoru Matsunaga

Satoshi Hashimoto

Shingo Taniguchi

Takao Ichii

Nobuyuki Masumura

Hiroshi Sato

Yoshikiti Teramoto

Kazuhiro Meguro

Eishou Nakano

Satoshi Hirose

Kenichi Nakamura

Shigeru Saitoh

Nobuhiro Moriyama

Tomoo Susa

Masamichi Akatsu

Hiromitsu Makita

Masahiro Segawa

Haruko Kakutani

Mitsuru Ohta

Masaru Satou

Hirokazu Matsui

Takeo Higashi

Mitsuru Itoh

Takuo Sekita

Hiroshi Ochiai

Sueo Watanabe

Kosuke Abe

Syuji Terasaki

A composition is formed by blending a vinylidene fluoride resin having a relatively high molecular weight and an improved crystallinity represented by a difference Tm&#x2212;Tc of at most 32&#xb0; C. between an inherent melting point Tmand a crystallization temperature Tc of the resin with a plasticizer and a good solvent for vinylidene fluoride resin, and the composition is melt-extruded into a hollow fiber-form. The hollow fiber-form extrudate is then cooled to be solidified from an outside thereof by introduction into cooling medium and subjected to extraction of the plasticizer and stretching, thereby forming a hollow fiber porous membrane of vinylidene fluoride resin characterized by co-presence of crystal oriented portion and crystal non-oriented portion recognizable by X-ray diffraction method. The resultant hollow fiber porous membrane of vinylidene fluoride resin has micro-pores of appropriate size and distribution, is excellent in mechanical strength represented by tensile strength and elongation at break and is useful as a water microfiltration membrane.

Porous water filtration membrane of vinylidene fluoride resin hollow fiber and process for production thereof

[Object] In a fishing line for capturing large fishes made by a polyvinylidenefluoride resin filament, a polyvinylidenefluoride resin filament wherein even by enhancing the tensile strength at break by enlarging the filament diameter than that of usual fishing line, an appropriate tensile elongation at break can be obtained, so that the rapid and enormous impact generated when large fishes have taken the bait can be reduced, and that has a homogenous fiber structure which generates almost no inner cavity when forming a filament with a large diameter, is developed.

Modified polyvinylidenefluoride resin monofilament and method for manufacturing thereof

There is provided a porous hollow fiber of vinylidene fluoride resin which has a water permeation rate that is large per fiber and little dependent on the length, has a large treatment capacity per volume of a filtering module, and is therefore suitable as a microfilter element. That is, a porous hollow fiber, comprising a vinylidene fluoride resin having a weight-average molecular weight of at least 3&#xd7;10, having a water permeation rate F (m/m&#xb7;day) measured at a pressure difference of 100 kPa and at a water temperature of 25&#xb0; C. in a range of test length L=0.2-0.8 (m) and expressed in a linear relationship with the test length L of: F=C&#xb7;L+F(formula 1) and satisfying requirements (a)-(d) shown below: (a) a average slope C (/day) of: &#x2212;20&#x2266;C&#x2266;0, (b) an intercept (basic permeability) F(m/m&#xb7;day) of: F&#x2267;30, (c) a relation between F(m/m&#xb7;day) and an average pore diameter P (&#x3bc;m) according to half-dry method of F/P&#x2267;300, and (d) an outer diameter of at most 3 mm.

Vinylidene fluoride based resin porous hollow yarn and method for production thereof

A vinylidene fluoride resin having a weight-average molecular weight as relatively high as 300,000 or higher is mixed with a plasticizer and good solvent for the vinylidene fluoride resin to obtain a composition. A molten extrudate of the composition in a hollow-fiber membrane state is contacted, on its outer side, with a cooling liquid inert to the vinylidene fluoride resin to thereby cool the extrudate. During the solidification, the vinylidene fluoride resin is moderately and mildly crystallized. Thus, a hollow-fiber porous vinylidene fluoride resin membrane is produced which has a high crystallinity represented by an enthalpy of crystal melting 58 J/g or higher. The hollow-fiber porous membrane obtained is excellent in mechanical strength represented by tensile strength and elongation at break and in chemical resistance. It is effectively used as a water microfiltration membrane.

Hollow-fiber porous water filtration membrane of vinylidene fluoride resin and process for producing the same

There is provided a porous membrane of vinylidene fluoride resin which has pores of appropriate size and distribution and also excellent mechanical strength represented by tensile strength and elongation at break and is useful as a microfiltration membrane or a separator for batteries. The porous membrane of vinylidene fluoride resin is characterized by the presence in mixture of a crystalline oriented portion and a crystalline non-oriented portion as confirmed by X-ray diffraction, and is produced by subjecting a melt-extruded composition obtained by mixing a vinylidene fluoride resin having a molecular weight distribution which is appropriately broad and high as a whole with a plasticizer and a good solvent for vinylidene fluoride resin, to cooling for solidification from one surface, extraction of the plasticizer and stretching.

Porous membrane of vinylidene fluoride resin and process for producing the same

A vinylidene fluoride resin composition which is stable to heat at molding temperatures and is free from foaming and coloration, and molded products made by forming the vinylidene fluoride resin composition are provided. The vinylidene fluoride resin composition may comprise 100 parts by weight of a vinylidene fluoride homopolymer; 2-20 parts by weight of a polyester plasticizer; 0.01-0.5 parts by weight of a phosphite compound; and a phenol compound.

Vinylidene fluoride resin compositions and articles molded therefrom

A vinylidene fluoride resin composition which is stable to heat at molding temperatures and is free from foaming and coloration, and molded products made by forming the vinylidene fluoride resin composition are provided. The vinylidene fluoride resin composition of the present invention comprises 100 parts by weight of a vinylidene fluoride resin, 2-20 parts by weight of a polyester plasticizer, 0.01-0.5 parts by weight of a phosphite compound. The vinylidene fluoride resin composition may further comprises a phenol compound.

A leader for fly fishing which has a high knot strength and a high tensile tenacity, is free from the formation of a shape-unstable portion (constriction) having a smaller diameter than an average thread diameter of the tippet section and the occurrence of melt fracture at a connecting portion between the tapered section and the tippet section, and shows an excellent natural drift property, can be produced by using a vinylidene fluoride-based resin having an inherent viscosity of 1.0 to 1.7 dl/g.

Leader for fly fishing

Provided in the present invention are a leader for fly fishing comprising a monofilament of a vinylidene fluoride resin, said leader consisting of a butt section, a taper section and a tippet section, a diametral unevenness of the tippet section being less than 10%, and a process for producing such a leader for fly fishing. The leader for fly fishing according to the present invention has pliability to allow unrestricted movement of the fly and enough strength to withstand the impact of striking, and is also small in diametral unevenness and capable of having its curling disposition or kink easily straightened out.

Leader for fly fishing and process for producing the same

A stretched PCTFE (polychlorotrifluoroethylene) film is provided with a good moisture-proofness (low moisture permeability) even at a relatively small thickness and at a small crystallinity The film is characterized by a crystallinity A (%) of 15-75% and a moisture permeability B (mg/m.sup.2.day) at a film thickness of 20 .mu.m, satisfying a relationship of B/(100-A).ltoreq.3.0. The film may suitably be produced through a process characterized by a sequence of a relatively low-temperature melt-extrusion and a low temperature stretching. The film is suitably used for constituting moisture-proof packaged products, such as an EL device or a packaged drug product.

Stretched polychlorotrifluoroethylene film, process for the production

A vinylidene fluoride resin fiber have a diameter of not less than 0.5 mm, and satisfy the formulae (1) and (2):

Vinylidene fluoride resin fiber and process for producing the same

A method of making a polyvinylidene fluoride porous membrane having an asymmetric structure, excellent mechanical strength and a narrow range of pore diameter distribution comprises: blending (i) 100 parts by weight of a vinylidene fluoride resin having an inherent viscosity, measured in dimethylformamide at a concentration of 0.4 g/dl and a temperature of 30.degree. C., of 1.4 to 15.0, (ii) 30 to 250 parts by weight of an aliphatic polyester plasticizer and, optionally and preferably, (iii) 1 to 50 parts by weight of a good solvent for vinylidene fluoride resin, to form a composition; extruding the so-formed composition to form a molten film; cooling one surface of the molten film by contact with a chill roll having a temperature of not more than 150.degree. C. and air-cooling the other surface to make a solid film; and extracting the plasticizer from the solid film.

Process of making vinylidene fluoride porous membrane

A laminated sheet suitable for high-frequency welding comprises a vinylidene fluoride resin layer (A), a bonding layer (B) consisting of a blend of vinylidene fluoride resin and a copolymer resin consisting of methyl methacrylate and alkyl ester of acrylate, whose alkyl group has 3-5 carbon atoms, a base-material layer (C) of vinyl chloride resin bonded to the bonding layer (B), and a base-cloth layer (D) bonded to the base-material layer (C). A bonded laminated sheet obtained by bonding two laminated sheets with high-frequency welding and the application of the bonded laminated sheet to tents are also disclosed.

Laminated sheet and a bonded laminated sheet

A polyvinylidene fluoride porous membrane has an asymmetrical structure, excellent mechanical strength such as tensile strength at break and elongation at break, and a desirable narrow range of pore diameter distribution. A method of preparing the porous membrane is also disclosed. The membrane comprises a vinylidene fluoride resin having an inherent viscosity from 1.3 to 15.0 (dl/g), and the membrane comprises pores which satisfy the following numerical expression (A):

Vinylidene fluoride porous membrane and method of preparing the same

A heat-resistant stretched film is obtained by stretching a resin composition comprising 100 parts by weight of a poly(arylene sulfide) of a substantially linear structure and 5 to less than 100 parts by weight of a melt-stable poly(arylene thioether-ketone). The poly(arylene sulfide) has a melt viscosity of at least 1,000 poises as measured at 310.degree. C. and a shear rate of 200 sec.sup.-1. The poly(arylene thioether-ketone) has predominant recurring units of the formula ##STR1## wherein the --CO-- and --S-- groups are bonded in the para position to each other through the benzene ring, and has the following physical properties (a)-(c):

Heat-resistant stretched film and production process thereof

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Tsuchiura, Japan

Toshiya Mizuno