Thermally removable pressure-sensitive adhesive sheet
AssigneeNitto Denko Corporation
InventorsHitoshi Takahira, Satomi Yoshie
Life of this patent
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Abstract
A thermally removable pressure-sensitive adhesive sheet includes a substrate and a pressure-sensitive adhesive layer that is provided on at least one side of the substrate and made from a polyester-based pressure-sensitive adhesive composition containing a polyester including at least a lactic acid unit, a dibasic acid unit, and a glycol unit, a foaming agent, and a crosslinking agent. The dibasic acid unit includes a dimer acid, the polyester has a weight average molecular weight of 20,000 to 200,000 and a glass transition temperature of −70 to −20° C. as measured using a differential scanning calorimeter at a temperature rise rate of 20° C./minute, and the polyester has a hydroxyl value of 1 to 60 mgKOH/g.
Claims9
A thermally removable pressure-sensitive adhesive sheet, comprising:
- a substrate;
- and
- a pressure-sensitive adhesive layer that is provided on at least one side of the substrate and made from a polyester-based pressure-sensitive adhesive composition comprising a polyester comprising at least a lactic acid unit, a dibasic acid unit, and a glycol unit, a foaming agent in an amount of from 5 to 60 parts by weight relative to 100 parts by weight of the polyester, and a crosslinking agent, wherein
- the dibasic acid unit comprises a dimer acid,
- the polyester has a weight average molecular weight of 20,000 to 200,000 and a glass transition temperature of −70 to −20° C. as measured using a differential scanning calorimeter at a temperature rise rate of 20° C./minute,
- the polyester has a hydroxyl value of 1 to 60 mgKOH/g, and
- the pressure-sensitive adhesive layer has a gel fraction of 40 to 85% by weight.
Dependencies are inferred from the claim text.