PURPOSE: To prevent the occurrence of streaky stain caused by raindrops and maintain a beautiful appearance by compounding a function-contg. fluororesin with a curative and a polymer of a hydrolyzable tetrafunctional silane compd. in a specified wt. ratio.
CONSTITUTION: This compsn. comprises 100 pts.wt. function-contg. fluororesin, 0.1-100 pts.wt. curative, and 0.1-100 pts.wt. polymer of a hydrolyzable tetrafunctional silane compd. The fluororesin has a number-average mol.wt. of 2.000-9,000, a glass transition temperature of 40°C or higher, and a hydroxyl value of 78-250mgKOH/g and is pref. a polymer of at least one fluoroolefin (e.g. tetrafluoroethylene) or a copolymer obtd. by copolymerizing a fluoroolefin and another copolymerizable monomer (e.g. a vinyl ether). The curative, which cross-links the fluororesin, is pref. an isocyanate- or aminoplast-based one. The polymer of the silane compd. has a silica content of 45wt.% or higher and is produced by using, e.g. a tetraalkoxysilane such as tetramethoxysilane.
TAKAYANAGI TAKASHI
KODAMA SHUNICHI
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