The use of cyclamic acid as a catalyst for the curing of hydroxyl-functional resins having a functionality greater than 2 provides a wrinkle finish. The hydroxy-function may be present in polyesters, epoxies, and acrylate or methacrylate resins, among others. The polyester resins which are able to provide such a finish have a hot plate melt flow of from about 20 mm to about 150 mm.
An epoxy coating powder composition and a method for controlling the denseness of cured wrinkle finish patterns are provided by the use of a curing agent mixture comprising a blocked Lewis acid, methylenedisalicylic acid and a ring-substituted homolog thereof having the formula ##STR1## wherein x and y are from 1 to 3, and R.sup.1 and R.sup.2 are, independently, hydrogen, alkyl groups having from 1 to 20 carbon atoms, aryl groups having from 6 to 10 carbon atoms, or aryl-substituted methylene groups; with the proviso that when x=y=3, R.sup.1 and R.sup.2 .noteq.hydrogen; wherein the ratio of methylene disalicylic acid and the ring-substituted homolog is from about 50:50 to about 2:98 by weight.
An epoxy coating powder composition and a method for controlling the denseness of cured wrinkle finish patterns are provided by the use of a curing agent mixture comprising a blocked Lewis acid, methylenedisalicylic acid and a ring-substituted homolog thereof having the formula ##STR1## wherein x and y are from 1 to 3, and R.sup.1 and R.sup.2 are, independently, hydrogen, alkyl groups having from 1 to 20 carbon atoms, aryl groups having from 6 to 10 carbon atoms, or aryl-substituted methylene groups; with the proviso that when x=y=3, R.sup.1 and R.sup.2 .noteq.hydrogen; wherein the ratio of methylene disalicylic acid and the ring-substituted homolog is from about 50:50 to about 2:98 by weight.
Powdered coating compositions and methods for obtaining improved wrinkled finishes with epoxy powder coatings are provided which utilize curing agents other than commercially available methylenedisalicylic acid.
The present invention provides a powder composition for forming a heat stable wrinkle finish coating and the wrinkle finish coatings formed there from. The composition of the present invention comprises a resin consisting essentially of one or more than one silicone resin having a condensable hydroxyl content of from 2% by weight to 7% by weight, a curing agent, preferably an aminoplast, and a wrinkle finish forming catalyst, preferably an amine salt of triflic acid. In another embodiment, the powder composition of the present invention may comprise a hydroxyl functional resin, preferably a polyester, mixed with the said silicone resin to aid in the adhesion of the coating to a substrate. The composition of the present invention may further comprise up to 60 phr of a filler, such as wollastonite, to aid in heat stability. The coatings of the sent invention provide outstanding heat stability at temperatures greater than 350.degree. F. and up to 550.degree. F., preferably up to 650.degree. F., for use on automobile or motorcycle exhaust systems, engine covers, manifolds, mufflers and engine parts, moves, fireplaces, stovepipes, grilles, ovens, and barbecue equipment, boilers, kettles, furnaces, steam lines, heat exchangers and any surface routinely exposed to high heat for an extended time.
Powdered coating compositions and methods for obtaining improved wrinkled finishes with epoxy powder coatings are provided which utilize curing agents other than commercially available methylenedisalicylic acid.
