Hydrogel
AssigneeSekisui Kasei Co., Ltd.
InventorsEisaku Sato, Takahiko Fujita
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Abstract
The hydrogel of the present invention is a hydrogel comprising a polymer matrix, water and a plasticizer, wherein the hydrogel is characterized in that the plasticizer loss ratio is less than 2, the swelling rate is 115% or less when the hydrogel is exposed to the environment of 40° C. and 90% RH for 1 hour, and the initial adhesive force to a Bakelite plate is 100 gf/20 mm or more in the environment of 23° C. and 55% RH. The plasticizer is preferably polyoxyalkylene alkyl ether and/or sugar. The initial high adhesive force is retained by suppressing the swelling of the gel due to invasion of water from the outside and reducing the loss of a plasticizer.
Claims3
A hydrogel comprising:
- a polymer matrix formed from a copolymer of
- a monofunctional monomer having one ethylenically unsaturated group, the monofunctional monomer comprising acrylamide and diacetoneacrylamide, the monofunctional monomer being present at 25-40% by weight with respect to 100% by weight of the hydrogel and
- a crosslinkable monomer, the crosslinkable monomer comprised of N,N′-methylenebisacrylamide and being present at 0.03 to 0.2% by weight with respect to 100% by weight of the hydrogel,
- water, and
- a plasticizer consisting of polyoxyethylene methyl glucoside having 10 to 20 oxyethylene units,
- in which the plasticizer is present at 21.12% to 54.23% by weight, with respect to 100% by weight of the hydrogel,
- wherein:
- the plasticizer loss ratio is less than 2,
- the swelling rate is 115% or less when the hydrogel is exposed to the environment of 40° C. and 90% RH for 1 hour, and
- the initial adhesive force to a Bakelite plate is 100 gf/20 mm or more in an environment of 23° C. and 55% RH.
Dependencies are inferred from the claim text.