Showa Denko K.k.

Ritsuko Azuma

Hiroshi Uchida

Kazuhiko Ooga

Atsushi Umino

Kazuya Kimura

An object of the invention is to provide carboxyl group-containing polyurethanes that have small curing warpage and can give cured products having excellent electrical insulating properties and flexibility, curable compositions that contain the carboxyl group-containing polyurethane and can give cured products having good electrical insulating properties, cured products obtained from the compositions, flexible circuit boards covered with the cured products, and processes for manufacturing flexible circuit boards. The carboxyl group-containing polyurethane is obtainable from materials including a (poly)carbonate polyol (a), a polyisocyanate (b) and a carboxyl group-containing polyol (c). The (poly) carbonate polyol includes an organic residue derived from a dimer diol and an organic residue derived from a polyol having a C10-20 alicyclic structure.

(Poly)carbonate polyol and carboxyl group-containing polyurethane obtained from the (poly)carbonate polyol

It is an object of the present invention to provide a curable composition which provides a cured product excellent in low warpage properties and long-term electrical insulation reliability and causes little bleeding during screen printing. The present invention is a curable composition comprising the following components (a) to (e): a component (a): polyurethane having a functional group capable of curing reaction and a carbonate bond, a component (b): &#x3b3;-butyrolactone, a component (c): diethylene glycol diethyl ether, a component (d): inorganic fine particles and/or organic fine particles, and a component (e): a compound having two or more epoxy groups in one molecule.

Curable composition

Disclosed is a thermosetting resin composition including; (A) a carboxyl group-containing polyurethane prepared by using (a) a polyisocyanate compound (b) polyol compounds (c) a carboxyl group-containing dihydroxy compound as raw materials, (B) a curing agent, wherein the polyol compounds (b) are one or more kinds of polyol compound(s) selected from Group (I) and one or more kinds of polyol compound(s) selected from Group (II); Group I: polycarbonate polyol, polyether polyol, polyester polyol, and polylactone polyol, Group II: polybutadiene polyol, polysilicone having terminal hydroxyl groups, and such a polyol that has 18 to 72 carbon atoms and oxygen atoms present only in hydroxyl groups. The thermosetting resin composition can give a protection film for flexible printed circuits that has excellent long-term reliability of electric insulation, flexibility, and low warpage from curing shrinkage, and particularly low tackiness.

Thermosetting resin composition, thermosetting resin composition solution, film forming material and their cured product

Disclosed is a carboxyl group-containing polyurethane containing a structure derived from a polycarbonate diol (B), the polycarbonate diol (B) having: (i) a number-average molecular weight of 500 to 50,000; (ii) an alkylene group of 8 to 18 carbon atoms in its structure; and (iii) hydroxyl groups at both ends. The carboxyl group-containing polyurethane is suitable as materials of cured products that are excellent in adhesion with substrates, low warpage, flexibility, plating resistance, soldering heat resistance and long-term reliability.

Carboxyl group-containing polyurethane and uses thereof

A carboxyl group-containing polyurethane is capable of giving cured products excellent in adhesion with substrates, low warpage, flexibility, plating resistance, soldering heat resistance and long-term reliability. The carboxyl group-containing polyurethane includes a structure derived from a polyol compound having 1 to 10 hydroxyl groups and 18 to 72 carbon atoms per molecule. The carboxyl group-containing polyurethane is produced by reacting: (A) a polyisocyanate compound; (B) a polyol compound having 1 to 10 hydroxyl groups and 18 to 72 carbon atoms per molecule; and (C) a carboxyl group-containing dihydroxy compound (other than the compound (B)).

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Kawasaki, Japan

Ritsuko Azuma