Alkoxymethyl melamine crosslinkers
OwnerGeorge T. Spitz, George D. Vaughn +1inventors
InventorsGeorge T. Spitz, George D. Vaughn, Patricia A. Ball
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Abstract
Crosslinker compositions consisting essentially of 50 to 95 weight percent monomeric C1 to C8 alkoxymethyl melamine derivatives containing not more than about 0.20 wt. % of imino (>N—H) groups. Such compositions further comprise 5 to 50 weight percent oligomeric C1 to C8 alkoxymethyl melamine derivatives and are useful for low temperature curing of functional resins, e.g. with active hydroxyl groups, for wood, automotive, appliance, coil and other coatings.
Claims16
A crosslinker composition consisting essentially of
- (a) 50 to 95 weight percent monomeric C1 to C8 alkoxymethyl melamine derivatives containing not more than about 0.20 wt. % of imino (>N—H) groups;
- and
- (b) 5 to 50 weight percent oligomeric C1 to C8 alkoxymethyl melamine derivatives, wherein
- (i) when said composition comprises from 5 to 20 wt. % oligomer, said composition has an imino content of less than 0.20 wt. %;
- (ii) when said composition comprises from 20 to 30 wt. % oligomer, said composition has an imino content, I, defined by the algorithm, I<0.02X-0.2, where X is the weight percent oligomer in the composition and I is expressed in weight percent imino;
- (iii) when said composition comprises from 30 to 50 wt. % oligomer, said composition has an imino content of less than 0.7 wt. %
A crosslinker composition comprising monomeric and oligomeric alkoxymethylated melamine, wherein monomeric alkoxymethylated melamine molecules have 6 moles of substituent groups attached to pendant nitrogen atoms per mole of monomeric melamine, wherein said substituent groups are selected from the group consisting of imino [>N—H], methylol [>N—CH2OH], alkoxymethyl [>N—CH2OR] and acetal [>N—CH2OCH2OR];
- and wherein difunctional bridging groups between melamine units in oligomeric alkoxymethylated melamine are selected from the group consisting of methylene groups [>N—CH2—N<] and methylene ether [>N—CH2OCH2—N<] groups;
- wherein:
- (a) monomeric alkoxymethylated melamine units comprise at least 50 and up to 95 percent by weight of the monomeric and oligomeric alkoxymethylated melamine units in the composition as determined by size exclusion chromatography,
- (b) alkoxymethyl groups comprise at least 5.0 moles of substituent groups attached to pendant nitrogen atoms per mole of monomeric melamine,
- (c) said alkoxymethyl groups on each melamine unit are methoxymethyl or mixtures of methyoxymethyl and higher alkoxymethyl groups;
- (d) when said composition comprises from 5 to 20 wt. % oligomer, said composition has an imino content of less than 0.20 wt. %;
- (e) when said composition comprises from 20 to 30 wt. % oligomer, said composition has an imino content, I, defined by the algorithm, I<0.02X-0.2, where X is the weight percent oligomer in the composition and I is expressed in weight percent imino;
- (f) when said composition comprises from 30 to 50 wt. % oligomer, said composition has an imino content of less than 0.7 wt. %.
Dependencies are inferred from the claim text.