Patent ID: 6783910
Filing Date: 2004-08-31
Classification: G03G

Abstract:
A toner for developing an electrostatic image, comprising:toner particles, which are comprised of 100 parts by weight of a binder resin, and 0.5 to 20 parts by weight of a long-chain compound, wherein the binder resin comprises a vinyl resin having (i) an acid value of 10-50 mgKOH/g, (ii) an OH value of at most 20, (iii) peaks at least in a molecular weight region of 3.5Ã—103-2Ã—104 and a molecular weight region of 1Ã—105-1Ã—106, respectively, in a molecular weight distribution according to GPC, (iv) a molecular weight distribution according to GPC such that a molecular weight region of at most 4.5Ã—104 and a region of a larger molecular weight than 4.5Ã—104 provide an areal ratio of 3:7-8.5:1.5, wherein the vinyl resin has a number-average molecular weight (Mn) of 2.5Ã—103-5Ã—104 and a weight-average molecular weight (Mw) of 1Ã—104-1.5Ã—106 the long-chain compound comprises a long-chain alkyl alcohol having (a) an OH value of 20-100 mgKOH/g, (b) a melting point of at least 91Â° C., (c) Mw/Mn of at most 3 and the long-chain alkyl alcohol is represented by the following formula (3): CH3(CH2)xCH2OH wherein X is 35-200, and is contained so as to satisfy conditions of the following formulas (1) and (5): acid value of binder resin+OH value of long-chain alkyl alcohol>(Â¼)Ã—OH value of binder resin,â€ƒâ€ƒFormula (1) frÃ—(acid value of binder resin)+faÃ—(OH value of long-chain alkyl alcohol)âˆ’(Â¼)Ã—frÃ—(OH value of binder resin)>10â€ƒâ€ƒFormula 5 wherein fr and fa denote content factors of the binder resin and long-chain alkyl alcohol, respectively, wherein fr=(R/(a+&agr;+R) and fa=(a/(a+&agr;+R) and R is the content of the binder resin, a is the content of the long-chain alkyl alcohol, and &agr; is the content of THF-insoluble resinous matter other than the long-chain alkyl alcohol.