Electrophotographic process uses toner comprising vinyl copolymer
AssigneeMitsui Toatsu Chemicals, Inc.
InventorsMasaaki Shin, Akio Fujiwara, Hiroshi Taniwaki
Life of this patent
Estimating the term…
Abstract
An electrophotographic toner, which can exhibit good fixation in high-speed copying and is not affected by an environment such as high humidity, is provided by containing, as a principal component thereof, a resin blend composed of (a) 40-90 wt. % of a vinyl copolymer (I) formed of 70-97 wt. % of an aromatic vinyl monomer, 3-30 wt. % of an alkyl fumarate which is a C.sub.1-8 monoalkyl or dialkyl ester and 0-5 wt. % of an acid monomer and having a number average molecular weight of 2,000-15,000 and (b) 10-60 wt. % of a vinyl polymer (II) having a number average molecular weight of 20,000-500,000.
Claims9
In a process of developing latent electrostatic images in a high speed electrophotographic copying machine operating at a copying speed of about 50 copies per minute, the improvement comprising:
- contacting the latent electrostatic images with a toner material comprising a coloringly effective amount of a colorant in combination with a resin blend composed of:
- (A) 40-90 wt. % of a vinyl copolymer (I) formed of 70-97 wt. % of an aromatic vinyl monomer, 3-30 wt. % of an alkyl fumarate which is a C.sub.1-8 monoalkyl or dialkyl ester and 0-5 wt. % of an acid monomer and having a number average molecular weight of 2,000-15,000;
- and (B) 10-60 wt. % of a vinyl polymer (II) having a number average molecular weight of 20,000-500,000.
Dependencies are inferred from the claim text.