An object is to provide an aqueous coating material composition having high viscosity expression property as well as a viscosity property of decreasing viscosity with increase in shear velocity; in particular, to provide an aqueous coating material composition that can form a multilayer coating film having excellent smoothness, clarity, flip-flop property, adhesion, and water resistance; in addition, to provide a method for forming a multilayer coating film using such aqueous coating material composition, as well as a coated article that has been coated with such aqueous coating material composition. As a solution, an aqueous coating material composition is provided that contains a polyester resin (A), acrylic resin particles (B), a curing agent (C), and a coloring pigment (D), wherein the polyester resin (A) is a resin containing a trifunctional or higher polyfunctional polycarboxylic acid (a1) and a polyol (a2) as monomer components.

The present invention relates to: a polyester resin having excellent heat resistance and solubility in solvents; and a coating composition which contains the same, and is thus capable of forming a coating film having excellent heat resistance, hardness, chemical resistance, pollution resistance, and hydrolysis resistance.

A process of forming a lactide copolymer includes forming a dimethylidene lactide molecule from an L-lactide molecule. The process also includes forming a functionalized lactide monomer from the dimethylidene lactide molecule. The process includes forming a mixture that includes the functionalized lactide monomer and a bisphenol A (BPA) monomer or a BPA-derived monomer. The process further includes polymerizing the mixture to form a lactide copolymer.

A transparent, heat-sealable coating for transparent PET packaging foils can be provided by using a heat-sealable lacquer based on styrene-containing copolymers, on poly(meth)acrylates, on at least one polyester and optionally on a tackifier, and also the process for the sealing of a foil coated with this lacquer. It is surprising here that, despite the use of a rubber based on styrene-containing polymers that is not optically compatible with polyesters and polymethacrylate, the transparency of the heat-sealable coatings is still very high.

A pigmented aqueous basecoat material is disclosed. The pigmented aqueous basecoat material includes a polyether-based reaction product which is preparable by a reaction of trimesic acid with at least one polyether of the general structural formula (I)

##STR00001##

R is a C.sub.3 to C.sub.6 alkylene radical and n is selected accordingly such that the at least one polyether possesses a number-average molecular weight of 500 to 5000 g/mol. The trimesic acid and the at least one polyether are used in the reaction in a molar ratio of 0.7/2.3 to 1.6/1.7 and the resulting reaction product possesses an acid number of 10 to 50 mg KOH/g.

A coating composition includes (a) a melamine resin having imino and methylol functional groups that together comprise 30 mole % or greater of the total functionality of the melamine resin; and (b) at least one polymer reactive with (a) that is obtained from components including polytetrahydrofuran and a carboxylic acid or anhydride thereof. The polytetrahydrofuran includes greater than 20 weight % of the components that form the polymer (b) and the carboxylic acid or anhydride thereof includes greater than 5 weight % of the components that form the polymer (b). The polymer (b) has an acid value of at least 15 based on the total resin solids of the polymer (b).

The present invention relates to a pigmented aqueous basecoat material including a polyether-based reaction product which is preparable by reaction of (a) at least one carboxy-functional component which is preparable by esterification reaction of at least one dihydroxycarboxylic acid (a1) with at least one dicarboxylic acid (a2) and/or the anhydride of a dicarboxylic acid (a2), the components (a1) and (a2) being used in a molar ratio of 0.5/3.0 to 1.7/1.8, with (b) at least one polyether of a general structural formula (I)

##STR00001##

in which R is a C.sub.3 to C.sub.6 alkylene radical and n is selected accordingly such that the polyether (b) possesses a number-average molecular weight of 500 to 5000 g/mol, the components (a) and (b) being used in the reaction in a molar ratio of 0.7/2.3 to 1.6/1.7, and the resulting reaction product possessing an acid number of 10 to 50 mg KOH/g.

The present invention relates to a pigmented aqueous basecoat material comprising a polyether-based reaction product which is preparable by reaction of (a) at least one dicarboxylic acid of the formula (I)
HOOCYCOOH(I)
in which Y is a divalent aliphatic, aromatic or araliphatic hydrocarbon radical having from 4 to 11 carbon atoms, with (b) at least one polyether of the general structural formula (II) ##STR00001##
in which R is a C.sub.4 to C.sub.6 alkylene radical and n is selected accordingly such that the polyether (b) possesses a number-average molecular weight of 200 to 4000 g/mol, where components (a) and (b) are used in the reaction in a molar ratio of 0.7/2.3 to 1.6/1.7 and the resulting reaction product possesses a number-average molecular weight of 500 to 15 000 g/mol and an acid number of less than 10 mg KOH/g.

The present invention relates to a pigmented aqueous basecoat material comprising a polyether-based reaction product which is preparable by reaction of (a) at least one dicarboxylic acid of the formula (I)
HOOCYCOOH(I)
in which Y is a divalent aliphatic, aromatic or araliphatic hydrocarbon radical having from 4 to 11 carbon atoms, with (b) at least one polyether of the general structural formula (II) ##STR00001##
in which R is a C.sub.4 to C.sub.6 alkylene radical and n is selected accordingly such that the polyether (b) possesses a number-average molecular weight of 200 to 4000 g/mol, where components (a) and (b) are used in the reaction in a molar ratio of 0.7/2.3 to 1.6/1.7 and the resulting reaction product possesses a number-average molecular weight of 500 to 15 000 g/mol and an acid number of less than 10 mg KOH/g.

The present invention relates to a polyester resin with excellent solubility in generic solvents, especially with excellent solubility at a temperature of 0 C. or lower. According to the present invention, by using the polyester resin with excellent solubility in generic solvents, solubility at a lower temperature, especially the solubility at a temperature of 0 C. or lower, is enhanced, making it easier to prepare paints, coatings and the like. The polyester resin related to the present invention contains 0.05 to 0.5 mol of an isosorbide-derived structural unit and 0.015 to 0.4 mol of a trihydric or higher alcohol-derived structural unit relative to 1 mol of a polycarboxylic acid-derived structural unit.