Resin compostions for electrophotographic toner
AssigneeSanyo Chemical Industries, Ltd.
InventorMasaharu Nishida
Life of this patent
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Abstract
Resin compositions, comprising a high molecular weight copolymer having a molecular weight of at least 300,000, obtained by copolymerizing a styrenic monomer and an acrylic or methacrylic monomer, with or without another monomer, in the presence of a polyfunctional polymerization initiator, have wide molecular weight distribution and are suitable as binders for electrophotographic toners.
Claims25
A resin composition suitable for electrophotographic toner, which comprises 10-50% by weight of a high molecular weight copolymer having a molecular weight of at least 300,000, obtained by copolymerizing (a) at least one aromatic vinyl monomer and (b) at least one alpha-methylene aliphatic monocarboxylic ester monomer, with or without (c) at least one other monomer, in the presence of at least one polyfunctional polymerization initiator, selected from the group consisting of a polymerization initiator having at least two peroxide groups and a polymerization initiator having at least one peroxide group and at least one polymerizable unsaturated group, and 50-90% by weight of at least one styrene-acrylic ester copolymer of lower molecular weight;
- said composition having a molecular weight distribution of at least about 20 and a glass transition temperature of about 40.degree. C.-about 80.degree. C.
Dependencies are inferred from the claim text.