Dainippon Ink and Chemicals, Incorporated

Kazuo Kuba

Mitsuru Kitada

Yutaka Hashimoto

Toshifumi Tamaki

Disclosed is an aqueous coating agent comprising a water dispersion (C) prepared by dispersing resin particles containing a water-dispersible polyurethane resin (A) and at least one compound selected from a hydrophobic polyester polyol (B-1) and a hydrophobic polyether polyol (B-2) in water, and a crosslinking agent (D) capable of reacting with a hydroxyl group, wherein the water-dispersible polyurethane resin (A) is obtained by reacting a polyester polyol (a-1), which is obtained by condensing a dicarboxylic acid containing an aromatic dicarboxylic acid as a main component with a polyol, with a polyisocyanate, and also contains 15 to 35% by weight of an aromatic cyclic structural unit, and wherein the hydrophobic polyester polyol (B-1) and/or the hydrophobic polyether polyol (B-2) are liquid at normal temperature and contain 20 to 50% by weight of an aromatic cyclic structural unit.

Water-base coating material

An aqueous urethane resin dispersion for bonding can be used in wet lamination and dry lamination and can be reactivated easily at a low temperature of about 50 to 70&#xb0; C. after drying, and is also superior in coatability, adhesive strength, and heat resistance. The aqueous dispersion of a polyurethane resin is superior in contact adhesiveness immediately after lamination and also has good permeability and good coatability not only on bases having smooth surfaces such as plastics and metals, but also on porous bases such as fibers, papers, and buffed leathers; an aqueous adhesive using the aqueous dispersion; and an article to which it is applied. The aqueous polyurethane resin dispersion has at least one of a sulfonate group and a carboxylate group, wherein an average particle diameter of the polyurethane resin is 0.05 to 0.30 &#x3bc;m and a surface tension of the aqueous dispersion (A) is 40 mN/m or less.

Aqueous polyurethane resin dispersion and aqueous adhesive

An aqueous dispersion of a polyurethane resin obtainable from compounds including: (A) an organic polyisocyanate; (B) a polyester polyol containing an aromatic metal sulfonate group; (C) an aliphatic polyol being free from aromatic metal sulfonate and having a hydroxyl value of from 10 to 350; and (D) at least one of a polyamine and a polyol each having a molecular weight of 300 or lower, wherein the content of said aliphatic polyol unit (C) amounts to at least 55% by weight based on the solid content of said polyurethane resin. Also disclosed is an aqueous adhesive comprising the polyurethane resin aqueous dispersion.

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Osaka, Japan

Kazuo Kuba