Patent ID: 7288301

Claim:
A thermal recording medium comprising a base sheet, a thermal recording layer provided on one side of the base sheet, and a back layer arranged on the opposite side of the base sheet, wherein the back layer comprises as a coating film-forming component a polyurethane resin which is obtained by reacting at least one kind of low-molecular weight polymer (hereinafter referred to as “compound 1”) having at least one active-hydrogen-containing group at one end of the molecule, and at least one kind of compound (hereinafter referred to as “compound 2”) having at least one active-hydrogen-containing group and at least one hydrophilic group except a hydroxyl group, with at least one kind of polyisocyanate (hereinafter referred to as “compound 3”); wherein at least one segment (hereinafter referred to as “segment 1”) is derived from at least one kind of compound 1, at least one another segment (hereinafter referred to as “segment 2”) derived from at least one kind of compound 2, and at least one further another segment (hereinafter referred to as “segment 3”) derived from at least one kind of compound 3; and wherein at least one kind of polysiloxane compound (hereinafter referred to as “compound 5”) having at least one active-hydrogen-containing group is further used as a reacting-component in addition to at least one kind of compound 1, at least one kind of compound 2 and at least one kind of compound 3; and the polyurethane resin comprises at least one segment (hereinafter referred to as “segment 5”) derived from at least one kind of compound 5.