Kuraray Co., Ltd.

Hitoshi Maruyama

Takuji Okaya

Kazutoshi Terada

Taku Tanaka

Ken Yuki

Naoki Fujiwara

Toshiaki Sato

Masato Nakamae

Junnosuke Yamauchi

Hirotoshi Miyazaki

Koichi Kajitani

Makoto Shiraishi

Shigeki Takada

Tetsuya Katayama

Isao Ono

Akimasa Aoyama

Sadahiko Shiraga

Hiroji Kohno

Koji Onishi

Tatsuaki Hattori

Kazunari Igarashi

Daisuke Miyake

Junichi Uemura

The present invention relates to an aqueous emulsion comprising a dispersant of a modified polyvinyl alcohol with an ethylene unit content of 2 to 9 mol % and a degree of hydrolysis of at least 95 mol %, a dispersoid of a polymer of an ethylenically unsaturated monomer, and a ratio (.eta.2 rpm/.eta.20 rpm) of Brookfield viscosity at 30.degree. C., 2 rpm (.eta.2 rpm) as against Brookfield viscosity at 30.degree. C., 20 rpm (.eta.20 rpm) being 1 to 1.8 when the latter viscosity (.eta.20 rpm) is adjusted to 5,000 to 10,000 mPa.multidot.S. The aqueous emulsion according to the present invention is excellent in structural viscosity (flowability, high speed application performance), provides coated layers with high water resistance and low-temperature stability, and can be suitably used extensively as an adhesive for paper, wood and plastics, as a binder for impregnated paper and non-woven products, as an additive for mortar, as a paint, and in paper and fiber processings.

Aqueous emulsion

A coating agent comprising a particulate PVA having an average particle diameter of 0.01 to 1 .mu.m has excellent applicability through blade coaters or roll coaters.

Paper coating agent

A size for yarn which minimizes thread break is described. The size comprises an aqueous solution of (I) a polyvinyl alcohol resin, (II) a modified starch, and a water-soluble cellulose compound (III), wherein the components are related by the following equations:

Sized yarn and process therefor

There is disclosed an emulsion composition which comprises an aqueous emulsion (A) obtained by emulsion polymerization of 100 parts by weight of an ethylenically unsaturated monomer in the presence of 1 to 15 parts by weight of a carboxyl group-modified polyvinyl alcohol such as itaconic acid-modified polyvinyl alcohol as the dispersant and a polyamide resin (B) such as polyamide epichlorohydrin. The above emulsion composition has a long pot-life and can easily be made into a film having a high wet strength and being excellent in water resistance, hot water resistance and heat resistance. Accordingly, it can effectively be utilized in a variety of applications including paint coating, adhesive, fiber sizing agent and paper coating.

Emulsion composition

Process for suspension polymerization of vinyl compound

There are disclosed a process for producing a vinyl ester polymer having a high degree of polymerization at a high efficiency, which process comprises subjecting a vinyl ester monomer to seed polymerization by the use of a vinyl ester polymer emulsion as a seed emulsion under the conditions in which the charge of a water-soluble initiator per unit volume (1 liter) of reactant liquid charge is 1.times.10.sup.-8 to 2.times.10.sup.-4 mol, and the charge of the water-soluble initiator per one particle of the vinyl ester polymer particles in the seed emulsion is 1.times.10.sup.-28 to 1.times.10.sup.-20 mol, and a process for producing a vinyl alcohol polymer at a high efficiency from the vinyl ester polymer thus obtained. According to these processes of the present invention, both a vinyl ester polymer and vinyl alcohol polymer each having a higher degree of polymerization can be produced with ease on an industrial scale.

Process for producing vinyl ester polymer and process for producing

There is disclosed a composition which comprises an aqueous emulsion selected from (A-1) aqueous emulsion comprising a dispersoid which comprises a vinyl ester polymer (1) and a copolymer a (meth)acrylic ester and a primary hydroxyl group-containing ethylenically unsaturated monomer (2), the polymer (1) being present principally in the central part of the dispersoid, the copolymer (2) having a glass transition temperature of lower than 50.degree. C. an being present principally in the peripheral part thereof; and a dispersant comprising a vinyl alcohol polymer and (A-2) aqueous emulsion comprising a dispersoid which comprises a copolymer of a hydrophobic unsaturated monomer such as (meth)acrylic ester and a primary hydroxyl group-containing ethylenically unsaturated monomer; and a dispersant comprising a vinyl alcohol polymer having a mercapto group at an end thereof and a (B) polyvalent isocyanate compound. Disclosed also are an adhesive comprising the aforementioned composition and a wooden product which is joined by the use of the adhesive. The above-disclosed adhesive is excellent in initial adhesivity, adhesive strength, water resistance and so forth.

Composition, adhesive and aqueous emulsion

There are disclosed a secondary suspending agent for suspension polymerization of a vinyl compound (vinyl chloride, etc.) which comprises an aqueous dispersion comprising as the dispersoid, a polyvinyl ester having a degree of hydrolysis of 60 mol% or less, an average degree of polymerization of 4000 or more and an average particle diameter of 100 .mu.m or less; a suspension stabilizing agent comprising 5 to 70% by weight of the secondary suspending agent (PVA, etc.) and 30 to 95% by weight of a water-soluble high molecular compound having a degree of polymerization of 500 or more, the agent being used for suspension polymerization of a vinyl compound; and a process for producing a vinyl polymer (PVC, etc.) comprising suspension polymerizing a vinyl compound by the use of the above suspension stabilizing agent. Both the agents are well suited for producing vinyl polymer granules enhanced in absorption rate of plasticizer, bulk density, removality of residual monomer and porosity.

Secondary suspending agent for suspension polymerization of vinyl

Ethylene-vinyl alcohol copolymers wherein ethylene content is 10-70 mol % diad syndiotacticity is not less than 55 mol %, and intrinsic viscosity [.eta.] is not less than 0.05 l/g when measured with a mixed solvent of 85 weight % of phenol and 15 weight % of water at 30 20 C., which show less decrease of resistance to gas permeation under high temperature and high humidity, while retaining resistance to get permeation under low humidity, transparency and melt moldability, and moldings and laminates formed thereof.

Ethylene-vinyl alcohol copolymers, moldings and laminates

The present invention relates to a method of aqueous printing on a recording medium for ink, the recording medium having an excellent ink absorbing property and a markedly excellent waterproof property, the method characterized in that the recording medium comprises a substrate containing a composition which comprises polyvinyl alcohol, chitosan and an aldehyde compound.

Method of aqueous ink printing on an ink absorbing layer being coated on

Provided are water soluble films comprising a modified polyvinyl alcohol containing 2-pyrrolidone ring. The films have excellent water solubility, which can be maintained over a long period of time and under the condition of being contacted with an alkaline or acid substance, and at the same time have an appropriate touch and flexibility.

Water soluble film

This invention provides a water-soluble binder and a hot-melt binder for ceramics molding, said binder being composed of a polyvinyl alcohol-based copolymer containing (meth)allyl group-containing nonionic monomer units or nitrogeneous group-containing nonionic monomer units.

Water-soluble binder and hot-melt binder for ceramics molding

This invention relates to a water resistant composition which comprises (A) polyvinyl alcohol, (B) a chitosan of which aqueous 1% solution has a viscosity not greater than 70 centipoise at 20.degree. C. and (C) an aldehyde compound, as well as a heat-sensitive recording sheet which comprises said composition. The composition has excellent water resistant properties and the heat-sensitive recording sheet has improved color forming properties and excellent resistance to water and solvents.

Water resistant composition and heat-sensitive recording sheet

This invention relates to a method of coating paper to improve the surface strength and printability thereof comprising applying to the paper a silicon-containing modified polyvinyl alcohol agent or its saponification product. This method gives outstanding results for printing purposes when coated onto paper objects. This invention also relates to a paper having a silicon-containing polyvinyl alcohol agents coated thereon.

Water-resistant compositions which comprise a modified polyvinyl alcohol having a silyl group in the molecule and an organic substance, useful as compositions for treating inorganic materials and defogging compositions.

Growing community of inventors

Kurashiki, Japan

Hitoshi Maruyama