摘要:
An essentially linear polyester oligomer having hydroxyl and carboxyl terminal groups for subsequent cure and its production are disclosed. This polyester oligomer is produced by first adducting approximately equimolar amounts of diol carrying two primary hydroxyl groups and a dicarboxylic acid anhydride to form an hydroxy acid. The carboxyl groups of this hydroxy acid are then esterified by reaction with an approximately stoichiometric proportion of diol carrying one primary hydroxyl group and one secondary hydroxyl group, the stoichiometry being based on the total hydroxyl content of the diol and the carboxyl content of the hydroxy acid, to form an hydroxyl-terminated oligomer. This hydroxyl-terminated oligomer is then adducted with a polycarboxylic acid monoanhydride having a carboxyl functionality of at least 3, this monoanhydride being used in an amount of 0.01 to 0.15 equivalents of anhydride per hydroxyl equivalent in the hydroxyl-terminated oligomer. The resulting polyester oligomer is essentially linear and possesses low solution viscosity at high resin solids content combined with high reactivity enabling low temperature cure with aminoplast resins.
摘要:
High solids thermosetting organic solvent solution coating compositions are disclosed which are particularly useful for sealing the pores in fiber reinforced plastics. These compositions contain a mixture of resins comprising (1) from 30% to 70% of one or more hydroxy functional resins having a number average molecular weight of at least about 700, a Gardner bubble viscosity less than about Z.sub.4 measured in methyl ethyl ketone at 90% solids at 25.degree. C., and at least 5% of the hydroxy groups thereof being primary hydroxy groups, (2) from 10% to 70% of low molecular weight epoxy ester made by esterifying one or more resinous polyepoxides having a 1,2-epoxy equivalency of at least 1.2 with an approximately stoichiometric proportion of monocarboxylic fatty acid to provide an essentially epoxy-free ester having a Gardner bubble viscosity less than Z.sub.4 at 75% solids in xylol at 25.degree. C., and (3) the balance of the mixture, but not less than 15% thereof, being a curing agent having a plurality of groups reactive with the hydroxy groups in the hydroxy resin and in the epoxy ester.
摘要:
Aqueous dispersions having low VOCs are dispersions or solutions of polyesters. The polyesters useful are formed from A) between about 30 and about 60 mole percent polycarboxylic acids, of which at least about 80 mole percent comprises cyclohexanedicarboxylic acids, B) between about 35 and about 70 mole percent polyols of which at least about 95 mole percent comprises diols, and between about 40 and about 100 mole percent of the polyol content comprising cycloaliphatic diols, and C) between about 5 and about 25 mole percent of a monomer having dihydroxy, monocarboxylic acid functionality. The molar ratio of (B+C)/A is between about 1.01 and about 1.30, whereby the polyester is hydroxyl-terminated having hydroxyl numbers of between about 20 and about 150 and acid numbers between about 30 and about 100. The weight average molecular weight of the polyester is between about 1000 and about 20,000. In aqueous dispersions or solutions, the acid functionality of the polyester is neutralized with base to at least about 40%.
摘要:
A low cost, high performance coating for sheet metal which is to be formed into siding for houses and automobile panels is made from a polyester prepared by the condensation of hexahydrophthalic acid and a mixture of 1,4-cyclohexanedimethanol and an acyclic polyol wherein the mole percent of acyclic polyol is from 50 to 60; and a crosslinking agent containing the --N--CH.sub.2 --OR moiety wherein R is hydrogen or an alkyl group having from 1 to 4 carbon atoms and the unsatisfied valence is attached to an organic group capable of incorporation into a film.
摘要:
A coating composition adapted to adhere to a chrome surface is disclosed in which a solvent soluble hydroxy-functional acrylic copolymer, including a copolymerized tertiary amine monomer in an amount of from 5% to 40% of the weight of the copolymer, is combined with an organic polyisocyanate curing agent for the soluble copolymer, this composition containing the copolymer and the polyisocyanate curing agent in amounts to provide an equivalent ratio of NCO:OH of from 1.2:1 to 0.5:1. The two components are provided as a two package system which is mixed prior to application.
摘要:
A thermosetting, organic solvent-based, primer coating composition for protecting metal surfaces which includes a solvent solution of: (a) a hydroxy-functional polyester resin; (b) a thermosetting acrylic resin; (c) a hydroxy-terminal polybutadiene resin, a hydroxy-terminal epoxidized polybutadiene resin, or mixtures thereof; (d) a blocked isocyanate crosslinker including at least one dimethyl pyrazole blocked isocyanate; (e) an aminoplast crosslinker including at least one melamine-formaldehyde condensate; (f) a catalyst; and, (g) a pigment. The primer exhibits excellent flexibility after curing to allow the primer to be coil coated onto metals as a thicker film and to have the metal subsequently formed without film fracture or loss of adhesion. The primer also has improved solvent release properties during curing to allow volatiles to readily escape therefrom, which facilitates coil coating of the primer onto metals as thicker films that, when cured into thick film hardened surface finishes, do not exhibit the typical blisters, craters, pops, voids and other surface defects. The primer can be cured as well at reduced temperatures which contributes to the reduction in surface defects. A fluorocarbon topcoat is usually coil coated and cured over the non-blistering primer coating, to yield a composite coated metal substrate having a surface finish that is free of blisters, craters, pops, and voids, and other surface defects.
摘要:
A silicone/polyester adduct comprises between about 5 and about 30 wt % of silicone adducted to between about 70 and about 95% polyester chains formed from polyfunctional acids plus polyfunctional acids and/or anhydrides. At least about 50 mole percent of the polyfunctional acids and/or anhydrides are cycloaliphatic.
摘要:
An hydroxy-functional polyurethane reaction product is disclosed which enables the provision of thermosetting solution coating compositions which cure at low temperature to form flexible coatings. These polyurethanes are provided by the reaction of an organic diisocyanate with a stoichiometric excess of an essentially linear hydroxy-functional polyester which is the polyesterification reaction product of C.sub.4 -C.sub.10 aliphatic dicarboxylic acid or anhydride thereof with a stoichiometric excess of C.sub.3 -C.sub.8 aliphatic diol providing an alcohol/acid molar ratio of 3/2 to 6/5. The reaction is substantially complete as indicated by an acid number less than 10, and the diisocyanate is used in an amount providing an NCO/OH ratio of from 2/3 to 12/13. The thermosetting solution coating composition is provided by an organic solvent having dissolved therein from 5-50% of total resin solids of a curing agent reactive with hydroxy groups together with the polyurethane which has been described. The preferred curing agent is a partially methylolated melamine which contains from about 5 mol percent to about 40 mol percent of the methylol group.
摘要:
A method of providing a stone chip-resistant finish to the undersurface of an automobile is disclosed in which the undersurface is coated with a cationically initiated liquid mixture of cationically curable polyepoxide, polyhydric alcohol, and a photoinitiator for an ultraviolet-activated cationic cure. The liquid mixture is applied at a resin solids content of at least about 50% and in a thickness to provide a cured coating of at least 2 mils thick, and the wet coating is cured by exposing it to ultraviolet light. The automobile undersurface is desirably primed with a cross-linked amine-functional polymer primer, and the coating includes from 1% to 8% of a finely divided silica which prevents running but does not interfere with the ultraviolet cure.
摘要:
An ultraviolet light-curable liquid coating composition for molded plastic objects is disclosed. The composition is a liquid mixture of a polyurethane oligomer polyacrylate and an hydroxy-functional polyacrylate ester. The polyacrylate ester is present in an amount of 5% to 95% of total polyacrylate. The composition is preferably in solution in alcoholic solvent having a solids content of from 40% to 90%. A photoinitiator is included to render the composition curable upon exposure to ultraviolet light.