Curable aminoplast acrylic polyol compositions, process for their preparation and methods of use

A curable aminoplast acrylic polyol composition containing, calculated as solids on all the solids of the composition,

• (a) 50 to 85% by weight of at least one type of an acrylic polyol having a glass transition temperature Tg of from 15 to <50° C., an equivalent weight of hydroxyl groups on solids of from 330 to 420, a hydroxyl number on solids of from 120 to 180 mg KOH/g, and a number average of the molecular weight (Mn) of 1,000 to 3,000 Dalton,
• (b) 15 to 50% by weight of at least one type of an alkylated amino formaldehyde resin
• having a formaldehyde content in accordance with DIN EN ISO 11402 4.3 of less than 0.10%,
• an amino compound on which the at least one type of the alkylated amino formaldehyde resin is based being selected from the group consisting of melamine, guanamine, benzoguanamine, urea, toluenesulfonamide and glycoluril, and the alkylated amino formaldehyde resin containing at least one type of alkyl groups having 1 to 12 carbon atoms, and the alkylated melamine formaldehyde resin having a ratio of the sum of hexa-alkoxy methyl melamine to the sum of penta-methoxy methyl melamine as determined by HPLC from 20 to 50, and
• (c) 0.5 to 5.0% by weight of at least one type of an acidic catalyst.