The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 09, 1996
Filed:
May. 20, 1994
Mitsuo Aoki, Numazu, JP;
Takahisa Kato, Numazu, JP;
Masanori Suzuki, Shizuoka, JP;
Tomoe Hagiwara, Fuji, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A positively-chargeable toner includes a binder resin, a coloring agent, and a quaternary-ammonium-base containing copolymer with a weight-average molecular weight of 5,000 to 25,000, which included a repeat unit of formula (I), and a repeat unit of formula (II): ##STR1## wherein R.sup.1 is a hydrogen atom or a methyl group; R.sup.2 is a hydrogen atom or a methyl group; R.sup.3 is an alkylene group, and R.sup.4, R.sup.5 and R.sup.6 are an alkyl group. The quaternary-ammonium-base containing copolymer may further include a repeat unit of formula (III): ##STR2## wherein R.sup.7 is a hydrogen atom or a methyl group; and R.sup.8 is an alkyl group.