Low bake melamine cured coating compositions
US7619019B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 2006 |
| Grant date | Nov 17, 2009 |
| Priority date | — |
| Expiry date | Sep 20, 2027 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L67/00
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention provides reactive aqueous or solvent borne compositions comprising one or more low-temperature curing alkylether functional aminoplast resins having an average degree of polymerization of from 1.0 to 2.0, preferably alkylether group containing melamines, one or more hydroxyl group containing resins or polymers, such as acrylics and polyesters, one or more unblocked acid catalysts each having a pKa of 0.25 to 1.0, such as organic sulfonic acids, and one or more volatile amines, e.g. N-dipropylamine, that have a relative evaporation rate (RER) of 50-500, wherein, RER equals (p)(M)/11.6, with p being the vapor pressure of the amine in mm Hg and M being the molecular weight of the amine. The compositions cure at from 60° C. to 135° C., e.g. below 105° C., to form durable coatings suitable for plastic substrates, such as automotive plastics. The present invention also provides methods of forming the compositions comprising mixing the said aminoplast resins, hydroxyl group containing resins or polymers, unblocked acids and volatile amines to form a mixture, wherein the acids and the amines are added separately into the mixture.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.