Electrophotographic developer comprising polyester resin of specified acid and hydroxyl valves

Claim 2

An electrophotographic developing toner composition which comprises a colorant and a polyester, said polyester having an acid value of 5 KOH mg/g or less and a hydroxyl value of 50 KOH mg/g or less, a softening point of 80° to 140° C. and a flow starting point with a difference of 10° to 40° C. between said softening point and said flow starting point; said polyester being linear and noncrosslinked.

Claim 3

A composition as claimed in claim 1, which further comprises an electric charge-controlling agent.

Claim 4

A composition as claimed in claim 2, in which said agent is for positive charging.

Claim 5

The composition as claimed in claim 1, in which said polyester has and a diol component which is an alkylene oxide adduct of bis-phenol A.

Claim 6

A composition as claimed in claim 3, in which said agent is a vinyl polymer having a monomer unit of an amine.

Claim 7

A composition as claimed in claim 2, in which said agent is for negative charging.

Claim 8

The composition as claimed in claim 6, wherein the negative charge controller is selected from the group consisting of a metal complex salt of monoazo dye, nitrohumic acid and salt thereof, materials having a nitro group, materials having a halogen element, sulfonated copper phthalocyanine, and maleic acid anhydride copolymer.

Claim 9

The composition as claimed in claim 1, wherein the polyester comprises an alcohol monomer selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, bisphenol A, hydrogenated bisphenol A, polyoxyethylene bisphenol A, polyoxypropylene bisphenol A, dihydric alcohol, sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitane, pentaerythrytol, dipentaerythrytol, tripenterythrytol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycelol, diglycelol, 2-methylpropane-triol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane and 1,3,5-trihydroxybenzene.

Claim 10

The composition as claimed in claim 1, wherein the polyester comprises an acid monomer selected from the group consisting of maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexane dicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, alkenyl succinic acids, alkyl esters of alkenyl succinic acid, dibasic carboxylic acid, 1,2,4-benzene tricarboxylic acid, 2,5,7-naphthalene tricarboxylic acid, 1,2,4-naphthalene tricarboxylic acid, 1,2,4-butane tricarboxylic acid, 1,2,5-hexane tricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylene carboxypropane, tetra(methylenecarboxyl)methane, 1,2,7,8-octane tetra-carboxylic acid, trimer acid anhydride, and alkyl esters thereof, alkenylesters thereof and aryl esters thereof.

Claim 11

The composition as claimed in claim 1, wherein the polyester comprises at least one member selected from the group consisting of 1,2,4-benzene tricarboxylic acid, trimethyl 1,2,4-benzene tricarboxylate, triethyl 1,2,4-benzene tricarboxylate and tri-n-butyl 1,2,4-benzene tricarboxylate, tri-iso-butyl 1,2,4-benzene tricarboxylate, tri-n-octyl 1,2,4-benzene tricarboxylate, tri-2-ethylhexyl 1,2,4-benzene tricarboxylate, tribenzyl 1,2,4-benzene tricarboxylate and tris(4-isopropylbenzyl) 1,2,4-benzene tricarobxylate.

Claim 12

The composition as claimed in claim 1, wherein the colorant is selected from the group consisting of carbon black, copper phthalocyanine, monoazo type pigment, disazo type pigment anthraquinone type pigment, and rohdamine type dye.

Claim 13

An electrostatic developing carrier which comprises core particles and a coating on said core particles, said coating comprising the composition of claim 1.

Claim 14

In a heat roller fixing electrophotographic process for developing a latent image using a toner composition comprising the steps of developing, transferring the heat roller fixing, the improvement comprising using as said toner composition the composition of claim 1.

Claim 15

An electrophotographic developing toner composition which comprises a colorant and a polyester, said polyester having an acid value of 5 KOH mg/g or less and a hydroxyl value of 50 KOH mg/g or less, a softening point of 90° to 150° C. and a flow starting point with a difference of 15° to 50° C. between said softening point and said flow starting point.

Claim 16

An electrophotographic developing toner composition which comprises a colorant and a polyester, said polyester having an acid value of 5 KOH mg/g or less and a hydroxyl value of 50 KOH mg/g or less, a softening point of 90° to 150° C. and a flow starting point with a difference of 15° to 50° C. between said softening point and said flow starting point.

Claim 17

The composition as claimed in claim 14, in which said polyester has been produced by using a monomer having three or more reactive groups.

Claim 18

The composition as claimed in claim 15, which further comprises an electric charge-controlling agent for positive charging.

Claim 19

The composition as claimed in claim 16, wherein the positive charge controller is present in an amount of from 0.1 to 8.0 parts by weight based on 100 parts by weight of a thermoplastic resin.

Claim 20

The composition as claimed in claim 14, in which said polyester has a and a diol monomer for the polyester which is an alkylene oxide adduct of bisphenol A.

Claim 21

A composition as claimed in claim 18, in which said polyester has a polybasic acid component of the polyester has the formula (I): ##STR2## in which n is 3 or 4 and R is an alkyl group, an alkenyl group or an aryl group, having 1 to 18 carbon atoms.

Claim 22

A composition as claimed in claim 19, in which the polyester contains 2 to 50 mole percent, based on the entire acid component, of the polybasic acid component having the formula (I).

Claim 23

A composition as claimed in claim 19, in which the polybasic acid monomer having the formula (I) is selected from a triester of an alcohol having 8 carbon atoms and 1,2,4-benzene tricarboxylic acid, trimethyl 1,2,4-benzenetricarboxylate and triethyl 1,2,4-benzene-tricarboxylate.

Claim 24

The composition of claim 14, which further comprises an electric charge-controlling agent.

Claim 25

An electrostatic developing carrier which comprises core particles and a coating on said core particles, said coating comprising the composition of claim 14.

Claim 26

In a heat roller fixing electrophotographic process for developing a latent image using a toner composition comprising the steps of developing, transferring the heat roller fixing, the improvement comprising using as said toner composition the composition of claim 14.