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US 6,783,910 B2Granted
Toner for developing electrostatic image
AssigneeCanon Kabushiki Kaisha
InventorsTakaaki Kohtaki, Makoto Unno, Yushi Mikuriya, Tadashi Doujo
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Abstract
A toner for electrostatic imaging has a vinyl resin binder with an acid value of 2.5-70 mgKOH/g and (i) a long-chain alcohol with an OH value of 10-120 mg/KOH/g or (ii) a long-chain alkyl carboxylic acid with an acid value of 5-120 mg/KOH/g, wherein the acid value of the resin binder+either (i) OH value of the alcohol or (ii) acid value of the acid>(¼)×OH value of the binder.
Claims11
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 3.5×103-2×104 and a molecular weight region of 1×105-1×106, 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 4.5×104 and a region of a larger molecular weight than 4.5×104 provide an areal ratio of 3:7-8.5:1.5, wherein the vinyl resin has a number-average molecular weight (Mn) of 2.5×103-5×104 and a weight-average molecular weight (Mw) of 1×104-1.5×106
- 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 91° 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>(¼)×OH value of binder resin, Formula (1)
- fr×(acid value of binder resin)+fa×(OH value of long-chain alkyl alcohol)−(¼)×fr×(OH value of binder resin)>10 Formula 5
- wherein fr and fa denote content factors of the binder resin and long-chain alkyl alcohol, respectively, wherein fr=(R/(a+α+R) and fa=(a/(a+α+R) and R is the content of the binder resin, a is the content of the long-chain alkyl alcohol, and α is the content of THF-insoluble resinous matter other than the long-chain alkyl alcohol.
5 more elements
Dependencies are inferred from the claim text.