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US 5,057,392 AGranted
Low fusing temperature toner powder of cross-linked crystalline and amorphous polyester blends
AssigneeEastman Kodak Company
InventorsJohn M. McCabe, John C. Wilson
Life of this patent
Estimating the term…
Abstract
A low fusing temperature toner powder with excellent keep and grindability characteristics is provided which employs a polyblend of a crystalline polyester and an amorphous polyester that has been cross-linked with an epoxy novolac resin in the presence of a crosslinking catalyst.
Claims13
A process for preparing a polyblend for a low fusing temperature toner powder comprising the steps of:
- (a) admixing together:
- (1) a crystalline polyester having a glass transition temperature in the range of about -5.degree. to about 10.degree. C., a melting temperature in the range of about 90.degree. to about 110.degree. C.;
- a number average molecular weight in the range of about 1000 to about 3000 and a weight average molecular weight in the range of about 2000 to about 6000;
- (2) an amorphous polyester having a glass transition temperature in the range of about 55.degree. to about 75.degree. C., a number average molecular weight in the range of about 1000 to about 3000 and a weight average molecular weight in the range of about 2000 to about 9000 and containing an average of about 0.1 to about 1.0 reactable carboxyl groups per molecule;
- (3) a low molecular weight epoxy novolac resin having an epoxy functionality in the range of about 2.5 to about 6;
- and
- (4) a crosslinking catalyst;
- (b) melt blending the mixture at a temperature in the range of about 150.degree. to about 240.degree. C.;
- and
- (c) annealing the melt blended mixture at a temperature above the glass transition temperature of said amorphous polyester and below the melting temperature of said crystalline polyester for a time sufficient for said crystalline polyester to recrystallize as dispersed small particles within a matrix phase comprised of a cross-linked polymeric reaction product of said amorphous polyester and said epoxy novolac resin.
7 more elements
A polyblend of:
- (a) a crystalline polyester that comprises the reaction product of:
- about 50 to about 100 mole percent 1,6-hexanediol;
- about 0 to about 50 moles 1,4-butanediol;
- about 70 to about 100 mole percent terephthalic acid;
- about 0 to about 30 mole percent isophthalic acid;
- (b) an amorphous polyester that comprises the reaction product of:
- about 50 to about 99 mole percent terephthalic acid;
- about 0 to about 49 mole percent additional diacid(s);
- about 1 to about 15 mole percent trimellitic anhydride;
- about 50 to about 100 mole percent neopentyl glycol;
- and
- 0 to about 50 mole percent 1,4-cyclohexanedimethanol;
- and
- (c) an epoxy novolac resin that is a condensate of o-cresol and formaldehyde that has been reacted with epchlorohydrin and has an epoxy functionality in the range of about 4 to about 6.
11 more elements
Dependencies are inferred from the claim text.