Toner binder and toner

Abstract

There is provided a toner binder containing a polyester resin (P) composed of two or more polyester resins that are each obtained by polycondensation of a carboxylic acid component (x) and an alcohol component (y). The alcohol component (y) of at least one polyester resin (P1) constituting the polyester resin (P) comprises 30 to 100 molar % of an adduct (y1) of bisphenol A with 2 to 4 ethylene oxide molecules. The alcohol component (y) of at least one other polyester resin (P2) constituting the polyester resin (P) comprises 50 to 95 molar % of an aliphatic diol (y2) having 2 to 4 carbon atoms. The (P2) is other than the (P1), and the polyester resin (P) satisfies relationships as follows. 11.5≦SP value [(cal/cm 3 ) 1/2 ] of (P)≦13.0; and 5.2≦HLB value (according to the Oda method) of (P)≦7.1.

1 . A toner binder which contains a polyester resin (P) composed of two or more polyester resins which are each obtained by polycondensation of a carboxylic acid component (x) and an alcohol component (y), wherein the alcohol component (y) of at least one (P1) constituting the (P) contains 30 to 100 molar % of an adduct (y1) of bisphenol A with 2 to 4 ethylene oxide molecules, the alcohol component (y) of at least one (P2) constituting the (P) contains 50 to 95 molar % of an aliphatic diol (y2) having 2 to 4 carbon atoms, the (P2) is other than the (P1), and the (P) satisfies relationships (1) and (2),
   11.5 ≦SP  value [(cal/cm 3 ) 1/2 ] of ( P )≦13.0  (1)
     5.2≦HLB value [according to the Oda method] of ( P )≦7.1  (2).
   
     
     
         2 . The toner binder according to  claim 1 , wherein the polyester resin (P1) and/or (P2) is one in which 5 molar % or more of terminal hydroxyl groups are esterified with a monocarboxylic acid (x1), one in which 5 molar % or more of terminal carboxyl groups are esterified with a monool, or one in which 5 molar % or more of terminal hydroxyl groups are modified to vinyl groups. 
     
     
         3 . The toner binder according to  claim 1 , wherein the carboxylic acid component (x) of the polyester resin (P1) and/or (P2) includes a monocarboxylic acid (x1) and a polycarboxylic acid (x2), and 80 to 100 molar % of the (x) is an aromatic carboxylic acid. 
     
     
         4 . The toner binder according to  claim 1 , wherein the adduct (y1) of bisphenol A with 2 to 4 ethylene oxide molecules in the alcohol component (y) of the polyester resin (P1) is an 85% or more adduct (y11) of bisphenol A with 2 ethylene oxide molecules. 
     
     
         5 . The toner binder according to  claim 1 , wherein the content of an adduct of bisphenol A with one ethylene oxide molecule in the adduct (y1) of bisphenol A with 2 to 4 ethylene oxide molecules is 1.5% or less. 
     
     
         6 . The toner binder according to  claim 1 , wherein the alcohol component (y2) that constitutes the polyester resin (P2) is ethylene glycol. 
     
     
         7 . The toner binder according to  claim 1 , wherein the polyester resins (P1) and (P2) satisfy relationship (3) and the (P2) satisfies relationship (4),
   100≧( P 2)[ G″ 120]/( P 1)[ G″ 120]≧1  (3)
     ( P 2)[ G′ 180]≧2000  (4)
   [wherein (P2)[G″120] means a loss elastic modulus (dyn/cm 2 ) of the polyester resin (P2) at 120° C., (P1)[G″120] means a loss elastic modulus (dyn/cm 2 ) of the polyester resin (P1) at 120° C., and (P2)[G′180] means a storage elastic modulus (dyn/cm 2 ) of the polyester resin (P2) at 180° C.]   
     
     
         8 . The toner binder according to  claim 1 , wherein the (P1) is a linear polyester resin [P1(A)], the (P2) is a nonlinear polyester resin [P2(B)], and the weight ratio of the [P1(A)] to the [P2(B)], [P1(A)]/[P2(B)], is 10/90 to 90/10. 
     
     
         9 . A toner which contains the toner binder according to  claim 1 , a colorant and, as necessary, one or more additives selected from a release agent, a charge controlling agent and a fluidizer.