PROCESS OF PRODUCING POLYMERIC BINDER FOR TONER Russian patent published in 2007 - IPC C08F212/08 C09D11/02 C08J3/16 

FIELD: polymer production.

SUBSTANCE: invention relates to production of polymeric binders for toner and can be used for copying appliances and printers. Process comprises separate preparation via emulsion polymerization of (i) low-molecule weight copolymer of styrene (α-methylstyrene), 2-ethylhexyl acrylate (or butyl acrylate) and methacrylic acid at monomer weight ratio (88-91.5):(8-11):(0.5-1.0) with intrinsic viscosity in toluene 0.08-1.2 dL/g and (ii) high-molecule weight copolymer of styrene (α-methylstyrene) and 2-ethylhexyl acrylate (or butyl acrylate) at monomer weight ratio (88-92):(8-12) with intrinsic viscosity in toluene 1.0-1.28 dL/g. In both cases, polymerization is carried out at 60-70% to monomer conversion close to 100%. Resulting latexes of low- and high-molecule weight copolymers are supplemented by stopper and antioxidant and then mixed with each other at "dry" weight ratio between 70:30 and 75:25 and coagulated intrinsic viscosity in toluene 1.0-1.28 dL/g. with electrolyte solutions to form polymer characterized by intrinsic viscosity in toluene 0.4-0.45 dL/g and polydispersity M_w/M_n, which ensures bimodal molecular weight distribution of copolymer. The latter has melting (spreading) point 125-137^°C and softening temperature 70-75^°C.

EFFECT: improved quality of electrographic printing.

2 cl, 1 tbl, 4 ex