Nippon Shokubai Co., Ltd.

Other

Yamagata University

Yoshitomo Nakata

Akio Naka

Norihiro Wakao

Tomiyasu Ueta

Hideyuki Nishibayashi

Toshiaki Kuriyama

Daijo Tomihisa

Masaru Tanaka

Takashi Tomita

Kazumi Fujioka

Keiko Izumi

Daisuke Imai

Naoki Kobayashi

Asuka Sugawara

To Provide is a polymer having high antithrombogenicity compared to a conventional polymer having a glycerol group and suitable as a medical device material. It is the polymer having a structural unit derived from a glycerol group-containing monomer, and a structural unit derived from an unsaturated monomer having a structure in which an organic group having a structure site having 4 or more carbon atoms continuously bound is bound to an ethylenically unsaturated group; and satisfying a glass-transition temperature of 10&#xb0; C. or less and/or a glass-transition temperature of &#x2212;25&#xb0; C. or less at a saturated water content.

Polymer for medical device, medical device material and medical device prepared from the material, and monomer composition for polymer for use in production of medical device

There is provided a vinylpyrrolidone-based copolymer having as essential components N-vinylpyrrolidone and hydroxyl group-containing (meth)acrylate, which gives a favorable crosslinked coating film, and a method for production by which the copolymer is easily obtained. A vinylpyrrolidone-based copolymer of the present invention contains a constitutional unit derived from N-vinylpyrrolidone and a constitutional unit derived from hydroxyl group-containing (meth)acrylate at a specific ratio, in which a K value according to Fikentscher is 12 or more, water insoluble matter is 0.5% by mass (on the basis of solid content) or less, and each content of iron, nickel, chromium, sodium and calcium is 500 ppb (on the basis of mass: the same hereinafter) or less, or electrical conductivity of a 10% by mass-aqueous solution of the vinylpyrrolidone-based copolymer is 35 &#x3bc;S/cm or less.

Vinylpyrrolidone-based copolymer and a method for production thereof

It is an object of the present invention to provide a hydraulic composition which enables both of high fluidity and material separation reducing and can eliminate the delay of setting. The present invention is directed to a hydraulic composition comprising cement (A), a copolymer (B), a high-performance water reducing agent (C) and a powdery cement admixture (D), wherein the copolymer (B) comprises a repeating unit (I) represented by the following formula (1); (wherein Rrepresents a hydrogen atom or a methyl group. n is an integer of 2 to 4.), and a repeating unit (II) represented by the following general formula (2); (wherein R, Rand Rare same or different and each represents a hydrogen atom, a methyl group or a (CH)COOMgroup, and may form a structure of an anhydride when the total number of COOMgroups and COOMgroups are 2. Mand Mare same or different and each represents a hydrogen atom, a monovalent metal, a divalent metal, an ammonium group or an organic ammonium group, and p is an integer of 0 to 2).

Hydraulic composition

The present invention provides an innovative N-vinylamide polymer with decreased contents of impurities and suppressed coloration, a higher K-value, and preferably usable in a variety of fields such as cosmetic and pharmaceutical products, and to provide a production method of the polymer. An N-vinylamide polymer comprising an N-vinylamide monomer unit, wherein the N-vinylamide polymer has K-value of 60 or higher, a content of hydrolysis products of N-vinylamide monomer of 0.02% by weight or less, a content of ashes of 0.1% by weight or less, and hue of 10% aqueous solution of 10 or less measured according to JIS K0071.

N-vinyl amide polymer and production method thereof

The present invention provides a vinylpyrrolidone (co)polymer excellent in the color tone and the thermal yellowing resistance despite its low molecular weight. The vinylpyrrolidone (co)polymer, according to the present invention, is a vinylpyrrolidone (co)polymer which has a Hazen value of not more than 30 in the form of 5% aqueous solution and a K value of not more than 60 and is obtained by a process including the step of polymerizing a polymerizable monomer component with an azo compound initiator and/or an organic peroxide initiator, wherein the polymerizable monomer component includes N-vinylpyrrolidone, and wherein the azo compound initiator has a chemical structure as shown by &mdash;C(CH ) &mdash;N&boxH;N&mdash;C(CH ) &mdash;, and wherein the organic peroxide initiator is soluble in water or ethyl alcohol of 25&deg; C. in an amount of not smaller than 3 weight %.

Vinylpyrrolidone (co)polymer

The present invention provides: a vinylpyrrolidone polymer which exhibits good heat resistance and storage stability; a composition containing the vinylpyrrolidone polymer; a stabilization process for the vinylpyrrolidone polymer, and a preservation process for a vinylpyrrolidone polymer by which: even when the vinylpyrrolidone polymer is preserved for a long time or at high temperature, the physical properties such as molecular weight (K value) of the vinylpyrrolidone polymer can be prevented from changing, therefore the vinylpyrrolidone polymer can stably be preserved. To enhance the heat resistance and the storage stability, a vinylpyrrolidone polymer is mixed with a certain amount of antioxidant, and the oxygen concentration is suppressed to not higher than 50,000 ppm in a gas phase that contacts with the vinylpyrrolidone polymer when preserving.

Vinylpyrrolidone polymer and its stabilization and preservation processes

The present invention provides: a cyclic imino ether group containing polymer with an extremely reduced amount of residual cyclic imino ether group containing monomer; and a production process therefor. The cyclic imino ether group containing polymer is obtained by a process including the step of polymerizing a monomer component including a cyclic imino ether group containing monomer, and contains a cyclic imino ether group containing monomer unit in the ratio of not less than 0.1 mol %, wherein the amount of the cyclic imino ether group containing monomer remaining in the polymer is not more than 15 ppm. The production process for a cyclic imino ether group containing polymer comprises the steps of: radical-polymerizing a monomer component including a cyclic imino ether group containing monomer to obtain a cyclic imino ether group containing polymer; devolatilizing the resultant polymer by vacuum heating treatment to remove volatile components from the polymer; and adding a compound, reactable with the cyclic imino ether group, to the polymer in the devolatilizing step.

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Nishinomiya, Japan

Yoshitomo Nakata