| 摘要 |
1433348 Polymer blend; toner particles RICOH KK 27 July 1973 [17 Aug 1972] 35804/73 Heading C3P [Also in Division G2] A negatively charged developer comprises an electrically insulating carrier liquid and a toner dispersed therein, the toner comprising pigment or dye particles coated with a synthetic resin, the resin being either (A) a mixture of copolymer (a) which is a product of reacting a styrenebutadiene copolymer or a vinyltoluene-butadiene copolymer with an alkyl methacrylate or an alkyl acrylate having 6-18 carbon atoms in the respective alkyl groups, with copolymer (b) which is a copolymer of acrylic acid or methacrylic acid with an alkyl acrylate or alkyl methacrylate having 6-18 carbon atoms in the respective alkyl groups, or (B) a mixture of mixture (A) with a copolymer (C) which is a product of reacting a styrene-butadiene copolymer or a vinyltoluene-butadiene copolymer, with acrylic acid and an alkyl methacrylate having 6-18 carbon atoms in the alkyl groups or with methacrylic acid, and an alkyl methacrylate having 6-18 carbon atoms in the alkyl groups. The alkyl acrylate may be hexyl, decyl, lauryl or stearyl and the alkyl methacrylate may be either as detailed above for the alkyl acrylate or may be 2-ethylhexyl methacrylate. Examples of suitable dyes, pigments and insulating liquids are given. Copolymer (a) is prepared by dissolving the styrene-butadiene or vinyltoluene-butadiene copolymer, molecular weight 50,000-300,000, in toluene, adding an alkyl acrylate or alkyl methacrylate and reacting for 5 hours at 80-90‹ C. in the presence of an initiator such as lauroyl peroxide or benzoyl peroxide. Copolymer (b) is prepared by mixing acrylic or methacrylic acid with an alkyl acrylate or methacrylate, dissolving the mixture in toluene and reacting in the presence of azobisisobutyronitrile. Copolymer (c) is prepared by dissolving a styrene-butadiene or vinyltoluene-butadiene copolymer in toluene, adding an alkyl methacrylate and acrylic or methacrylic acid and reacting in the presence of a polymerization initiator.
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