Acid-curable cellulose esters containing melamine pendent groups
AssigneeEastman Kodak Company
InventorsPhillip M. Cook, David S. Kashdan
Life of this patent
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Abstract
Modified cellulose esters are described that are prepared by grafting melamine moieties onto the backbone of cellulose esters. The resulting materials are useful in coating applications for wood, leather, and metal substrates and yield highly solvent-resistant coatings with enhanced properties when heated in the presence of an acid catalyst.
Claims26
A substantially non-crosslinked modified cellulose ester comprising a cellulose ester having a melamine moiety grafted thereto.
A grafted cellulose ester of the formula:
- ##STR9## wherein R.sup.1 may be monomeric or oligomeric such that the average degree of polymerization is about 1 to about 3, and each R.sup.1 is, independently, of the structure:
- ##STR10## wherein q is 0 or a positive integer, each R.sup.3 is, independently, --H, --CH.sub.2 OH, --CH.sub.2 OCH.sub.3, --CH.sub.2 OC.sub.2 H.sub.5, --CH.sub.2 OC.sub.3 H.sub.7, or --CH.sub.2 OC.sub.4 H.sub.9,
- each R.sup.4, independently, has the same meaning as R.sup.3, provided that when R.sup.3 is --H, R.sup.4 must be other than --H,
- each R.sup.2 is independently, --H, ##STR11## x is 0 to 2.95, y is 0.05 to 0.5, provided that x+y is in the range of 0.05 to 3.0, and
- n is at least 30.
A coating composition comprising
- (A) a substantially modified cellulose ester comprising a non-crosslinked cellulose ester having a melamine moiety grafted thereto,
- (B) about 25 to about 95 weight %, relative to component (A), of a solvent, and
- (C) 0 to about 5 weight %, relative to component (A), of an acid catalyst.
An article comprising
- (A) a substrate, and
- (B) a cured coating composition comprising a substantially crosslinked modified cellulose ester comprising a cellulose ester having a melamine moiety grafted thereto.
A process for preparing a modified cellulose ester of the formula:
- ##STR19## wherein R.sup.1 may be monomeric or oligomeric such that the average degree of polymerization is about 1 to about 3, and each R.sup.1 is, independently, of the structure:
- ##STR20## wherein q is 0 or a positive integer, each R.sup.3 is, independently, --H, --CH.sub.2 OH, --CH.sub.2 OCH.sub.3, --CH.sub.2 OC.sub.2 H.sub.5, --CH.sub.2 OC.sub.3 H.sub.7, or --CH.sub.2 OC.sub.4 H.sub.9,
- each R.sup.4, independently, has the same meaning as R.sup.3, provided that when R.sup.3 is --H, R.sup.4 must be other than --H,
- each R.sup.2 is, independently, --H, ##STR21## x is 0 to 2.95, y is 0.05 to 0.5, provided that x+y is in the range of 0.05 to 3.0, and
- n is at least 30;
- comprising contacting
- (a) an ester of cellulose and at least one saturated monocarboxylic acid having 2 to 4 carbon atoms, wherein said cellulose ester has a degree of substitution per anhydroglucose unit of residual hydroxyl groups of about 0.1 to 2.0, and
- (b) a melamine compound which may be monomeric or oligomeric such that the average degree of polymerization is about 1 to about 3, and is of the formula ##STR22## wherein q is 0 or a positive integer in the presence of a solvent and a catalytic amount of an acid catalyst and under conditions such that the desired product is formed.
A process for curing a coating composition comprising:
- (A) a substantially non-crosslinked modified cellulose ester comprising a cellulose ester having a melamine moiety grafted thereto,
- (B) about 25 to about 95 weight %, relative to component (A), of a solvent, and
- (C) 0 to about 5 weight %, relative to component (A), of an acid catalyst,
- said process comprising subjecting said coating composition to heat under conditions such that the modified cellulose ester of component (A) becomes substantially crosslinked.
Dependencies are inferred from the claim text.