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:
Dec. 25, 1990
Filed:
Nov. 14, 1989
Mitsuo Aoki, Numazu, JP;
Nobuhiro Nakayama, Susono, JP;
Yasuo Asahina, Numazu, JP;
Hiroyuki Fushimi, Numazu, JP;
Kayo Makita, Numazu, JP;
Yasuaki Iwamoto, Numazu, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
The present invention relates to the positively chargeable black toner particles which comprise binder resins, carbonblack as a main colorant, quaternary anmonium salt of the following formula (I) as a charge control agent and .beta.-form Cu-phthalocyanine as a stabilizing agent for chargeability of toner particles without being affected by the change of environmental conditions. ##STR1## Wherein R.sub.1 is C.sub.1 -C.sub.8 alkyl or benzyl, R.sub.2 and R.sub.3 are each C.sub.1 -C.sub.18 alkyl, R is C.sub.1 -C.sub.118 alkyl or benzyl, X is hydroxy or amino, and Y is hydoroxy or hydrogen; (c) .beta.-form Cu-phthalocyanine; and (d) carbonblack. The present invention further relates to the two component dry-type developer composed by the improved above said positively chargeable toner particles and the carrier particles coated with silicone polylmers which have the strong durability without being changed to a supent carrier particles for a use of long time period.