Binder resin for toner, toner, and manufacturing method therefor

A binder resin, comprising:

• a polyester resin (A) which contains a constitutional unit derived from a polyhydric alcohol and a polycarboxylic acid, and has a softening temperature of 120° C. or lower;
• and
• a polyester resin (B) different from the polyester resin (A),
• wherein
• the polycarboxvlic acid is selected from the group consisting of aromatic dicarboxylic acid, aliphatic dicarboxylic acid and tri- or higher polycarboxylic acid;
• the aliphatic dicarboxylic acid is selected from the group consisting of sebacic acid, isodecylsuccinic acid, dodecenylsuccinic acid, maleic acid, fumaric acid, adipic acid, succinic acid;
• and esters and acid anhydrides thereof,
• the constitutional unit derived from a polyhydric alcohol contains a constitutional unit derived from isosorbide,
• the binder resin has a hygroscopicity index of 2 or less and
• the binder resin comprises a tetrahydrofuran-insoluble matter at 5% by mass or less.