The fluorine-containing copolymer water dispersion liquid constituent null which possesses normal temperature building a bridge

摘要

PROBLEM TO BE SOLVED: To obtain a cold crosslinkable fluorocopolymer aq, dispersion compsn. which has excellent low-temp. film formability, coating strength, weather resistance and other properties by incorporating a predetermined amt. of a hydrazine deriv. contg. a plurality of hydrazine residues into a particular fluorocopolymer aq. dispersion. ;SOLUTION: A monomer mixture (B), in an amt. of 20 to 99 pts.wt., comprising an alkyl ester of an (meth)acrylic acid having a 1-18C alkyl group and an ethylenically unsatd. monomer copolymerizable with the above ester and, in addition, contg. 0.1 to 20wt.% ethylenically unsatd. monomer having an active carbonyl group is emulsion polymerized in an aq. medium in the presence of 100 pts.wt. fluoropolymer particle (A) to prepare a fluorocopolymer aq. dispersion having an average particle diameter of 0.05 to 3μm. A hydrazine deriv. contg. a plurality of hydrazine groups (e.g. phthalic dihydrazide) is added, to the aq. dispersion, in such an amount that the amt. of the hydrazine residue based on the active carbonyl group is 0.02 to 1mol equivalent to obtain a cold crosslinkable copolymer aq. dispersion compsn.;COPYRIGHT: (C)1997,JPO