Binder for electrostatic image developing toner
Provided is a binder for an electrostatic image developing toner using a polyester resin in which at least a part of a carboxylic acid component (a) and/or an alcohol component (b) comprises a carboxy-modified polyolefin or a hydroxyl-terminated polyalkadiene that may be hydrogenated containing an aliphatic hydrocarbon group (x) having a carbon number of 100 to 1,000. The binder is excellent in environmental stability and does not generate a peculiar odor around a copier or a printer when the binder is used in a toner, and a toner using the binder.
1. A binder for use in an electrostatic image developing toner, comprising: a polyester resin (A) comprised of constituents of a carboxylic acid component (a) and an alcohol component (b), at least a part of the carboxylic acid component (a) is selected from (Xa1) and (or at least a part of the alcohol component (b) is selected from (Xb), wherein (Xa1) and (Xb) comprise an aliphatic hydrocarbon group (x) having a carbon number of 100 to 1000, the average functional group number of (Xa1) and (Xb) being 1.6 or more, wherein:
(Xa1) is a carboxy-modified unsaturated bond-containing polyolefin in which the number of unsaturated bonds is 0.4 to 10 per 1000 carbon atoms in the unmodified polyolefin and has at least one functional group selected from the group consisting of a carboxyl group, an ester group and an acid anhydride group; and
(Xb) is an alcohol containing the aliphatic hydrocarbon group (x) and has a hydroxyl group, and
wherein the component (a) comprises other polycarboxylic acid and/or the component (b) comprises other polyol, whereby, in a molecular chain of the (A), a portion between the (Xa1)'s, (Xb)'s, or (Xa1) and (Xb) adjacent to each other in the molecular chain and a portion between the molecular terminal and the nearest of (Xa1) and (Xb) to the molecular terminal comprise said other polyol, said other carboxylic acid, or a polycondensale of said other polyol and said other polycalboxylic acid.
2. The binder according to claim 1 , wherein
the polyester resin (A) contains in the constituents thereof 0.1 to 20% by weight of the aliphatic hydrocarbon group (x).
3. The binder according to claim 1 , wherein
the carboxy-modified unsaturated bond-containing polyolefin (Xa1) comprises maleic acid (anhydride)-modified polyolefin.
4. The binder according to claim 1 , wherein
the alcohol (Xb) containing the aliphatic hydrocarbon group (x) comprises a hydroxyl-terminated polyalkadiene (Xb1) that may be hydrogenated.
5. The binder according to claim 1 , wherein
the average functional group number of (Xa1) and (Xb) is between 1.6 and 6.
6. The binder according to claim 1 , wherein
the carboxy-modified unsaturated bond-containing polyolefin (Xa1) is obtainable by thermally adding an unsaturated dicarboxylic acid or an ester forming derivative thereof to an unsaturated bond-containing polyolefin using the ene reaction.
7. The binder according to claim 1 , wherein
the number average molecular weight of the carboxy-modified unsaturated bond-containing polyolefin (Xa1) is from 1,500 to 14,000.
8. The binder according to claim 1 , wherein
the carboxy-modified unsaturated bond-containing polyolefin (Xa1) comprises a carboxy-modified thermal depolymerization type polyolefin.
9. An electrostatic image developing toner, comprising:
the binder according to claim 1 and a colorant.