Acrylic adhesive sheet, medical adhesive tape, and method for manufacturing the same

1. An acrylic adhesive sheet having a porous structure comprising a plurality of pores and having a water vapor transmission rate of 2,000 g/m 2 ·24 h to 3,500 g/m 2 ·24 h at 24° C. and 25% RH, and a porosity of 30% to 60%,

wherein the water vapor transmission rate is measured in accordance with ASTM E 96 conditions,

wherein the acrylic adhesive sheet is formed to have the porous structure by carrying out foaming and thermal curing on an aqueous acrylic adhesive composition sequentially at a first temperature (T1), a second temperature (T2), a third temperature (T3), and a fourth temperature (T4),

wherein the aqueous acrylic adhesive composition comprises at least one selected from the group consisting of an acrylic resin, a surfactant, a thermal foaming agent, water, and other additives, wherein the other additives are at least one selected from the group consisting of a curing agent, a wetting agent, an antifoaming agent, a neutralizer, a thickener, a molecular weight adjusting agent, an emulsifier, a tackifier, and an aqueous ammonia solution,

wherein the acrylic resin is formed by polymerizing a co-polymerizable monomer component comprising two or more acrylic monomers, and a content of acrylic acid in the total co-polymerizable monomers which form the acrylic resin is 0.7 wt % to 2 wt %, and a content of methyl methacrylate in the total co-polymerizable monomers which form the acrylic resin is more than 0 wt % and 10 wt %.

2. The acrylic adhesive sheet of claim 1 , wherein the pores have an average size of 500 nm to 100 μm.

3. The acrylic adhesive sheet of claim 1 , wherein the acrylic adhesive sheet has a thickness of 10 μm to 100 μm.

4. The acrylic adhesive sheet of claim 1 , wherein the aqueous acrylic adhesive composition comprises the acrylic resin in an amount of 40 wt % to 70 wt %.

5. The acrylic adhesive sheet of claim 1 , wherein the aqueous acrylic adhesive composition comprises a surfactant in an amount of 1 wt % to 10 wt %.

6. The acrylic adhesive sheet of claim 5 , wherein the surfactant comprises at least one selected from the group consisting of a cationic surfactant, an anionic surfactant, an amphoteric surfactant, a non-ionic surfactant, and a combination thereof.

7. The acrylic adhesive sheet of claim 1 , wherein the aqueous acrylic adhesive composition has a viscosity of 1,000 cp to 10,000 cp at 25° C.

8. The acrylic adhesive sheet of claim 1 , wherein the aqueous acrylic adhesive composition further comprises or does not further comprise a separate cross-liking agent.

9. A medical adhesive tape comprising the acrylic adhesive sheet according to claim 1 .

10. A method for manufacturing a medical adhesive tape of claim 9 , the method comprising:

applying an aqueous acrylic adhesive composition onto a release film;

forming an acrylic adhesive sheet on the release film by carrying out foaming and thermal curing on the applied aqueous acrylic adhesive composition sequentially at a first temperature (T 1 ), a second temperature (T 2 ), a third temperature (T 3 ), and a fourth temperature (T 4 ); and

attaching a base material onto one surface of the acrylic adhesive sheet,

wherein the first temperature to the fourth temperature satisfy the relationships of the first temperature (T 1 )<the third temperature (T 3 )<the second temperature (T 2 ) and the third temperature (T 3 ) >the fourth temperature (T 4 ).

11. The method of claim 10 , wherein the first temperature is formed at 0° C. to 80° C.

12. The method of claim 10 , wherein the second temperature is formed at 150° C. to 200° C.

13. The method of claim 10 , wherein the third temperature is formed at 90° C. to 120° C.

14. The method of claim 10 , wherein the fourth temperature is formed at 30° C. to 120° C.

15. The method of claim 10 , wherein foaming and thermal curing are carried out at each of the first temperature, the second temperature, the third temperature, and the fourth temperature for 0.5 minute to 3 minutes.

16. The method of claim 10 , further comprising:

forming an aqueous acrylic adhesive composition by mixing at least two selected from the group consisting of an acrylic resin, a surfactant, a thermal foaming agent, water, other additives, and a combination thereof,

wherein a separate cross-linking agent is or is not further mixed with the aqueous acrylic adhesive composition.