Toner for dry developing
AssigneeRicoh Company, Ltd.
InventorsHiroyuki Fushimi, Kohki Katoh, Masami Tomita, Yasuo Asahina, Tomomi Suzuki
Life of this patent
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Abstract
A toner for dry developing, containing a colorant and a binder and giving such a toner image on a transfer sheet upon fixation that has an image density I and a gross of G % when the toner deposits on the transfer sheet in an amount of M mg/cm.sup.2, wherein I, G and M have the following relationship: I=a.multidot.M+b where 0<a.ltoreq.3 and 0.ltoreq.b, G=.alpha..multidot.M+.beta. where 0<.alpha.<15 and 0.ltoreq..beta., and G.sub.AV .gtoreq.10 where G.sub.AV is an average of G when M=0.2, 0.4, 0.6, 0.8 and 1 mg/cm.sup.2.
Claims15
A toner for dry developing, comprising a colorant and a binder and giving a toner image on a transfer sheet upon fixation, said toner image having a density I and a gloss of G % when said toner deposits on said transfer sheet in an amount of M mg/cm.sup.2, said I, G and M having the following relationship:
- I=a.multidot.M+b
- where 0<a.ltoreq.3 and 0.ltoreq.b
- G=.alpha..multidot.M+.beta.
- where 0<.alpha.<15 and0.ltoreq..beta., and
- G.sub.AV .gtoreq.10
- where G.sub.AV is an average of G when M=0.2, 0.4, 0.6, 0.8 and 1,
- wherein said binder comprises a first resin and a second resin having a glass transition point different from that of said first resin and greater by no more than 5.degree. C. than that of said first resin,
- wherein said second resin is a styrene-acrylate copolymer having a number average molecular weight Mn of 3,000-30,000, a weight average molecular weight Mw of 9,000-50,000 and a ratio of Mw/Mn of no more than 3, and
- wherein the weight ratio of said first resin to said second resin is in the range of 95:5 to 60:40.
A toner for dry developing, comprising a colorant, and a binder including a first resin and a second resin having a glass transition point different from that of said first resin and greater by no more than 5.degree. C. than that of said first resin, wherein said first resin has a glass transition point of at least 55.degree. C. and a softening point of 100-120.degree. C., wherein said second resin has a number average molecular weight Mn of 3,000-30,000, a weight average molecular weight Mw of 9,000-50,000 and a ratio of Mw/Mn of no more than 3, and wherein the weight ratio of said first resin to said second resin is in the range of 95:5 to 60:40.
Dependencies are inferred from the claim text.