Heat-curable resinous coating composition

Claim 1

A heat-curable resinous coating composition comprising as a binder component (A) 5 to 90% by weight of a hydroxyl-containing resin selected from hydroxyl-containing acrylic resins and hydroxyl-containing polyester resins, (B) 5 to 50% by weight of an amino resin which reacts under heat with the hydroxyl groups of the hydroxyl-containing resin (A) to form a crosslinkage, and (C) 1 to 90% by weight of a crosslinkable and polyorganosiloxanes having a number average molecular weight of at least 500 and containing at least two silanol groups on an average per molecule and optionally containing an epoxy group, said polyoragnosiloxanes being obtained by hydrolyzing and co-condensing a silane represented by the following formula (II) R.sub.x.sup.2 Si(OR.sup.3)4-x (II) wherein R 2 and R 3 are same or different and each represents a monovalent hydrocarbon group having 1 to 13 carbon atoms, and x is 1, 2 or 3, optionally together with an epoxy-containing silane represented by the following formula (III) ##STR7## wherein R 4 and R 5 are same or different and each represents a monovalent hydrocarbon group having 1 to 13 carbon atoms, y is 1, 2 or 3, and G represents an epoxy-containing organic group, for example an organic group of formula (IV) or (V) below ##STR8## wherein R 6 represents a divalent hydrocarbon group having 1 to 13 carbon atoms, and two or more R 7 may be identical or different and each represents a hydrogen atom or a methyl group. and the coating composition optionally comprising as paint additives, at least one of organic solvents, pigments, ultraviolet absorbers, paint surface adjusting agents, curing catalysts and pigment dispersants.