JPH03212473A - Production of air-transmissible tacky tape or sheet - Google Patents

Abstract

PURPOSE:To obtain the title tape or sheet by simple process by applying a solution in which a specific tacky agent is dissolved onto a release sheet to form a tacky agent solution layer, spraying water to the solution layer, drying the solution layer and laminating the resultant layer onto an air-transmissible substrate. CONSTITUTION:An acrylic tacky agent obtained by copolymerizing a macromonomer is dissolved in a solvent and the resultant tacky agent solution is applied on a release sheet to form a tacky agent solution layer. Then water is sprayed on the surface of tacky agent layer by a spray gun, etc., while the tacky agent solution layer is kept in undried state and the solution layer is further dried by heating the solution layer to form a tacky agent layer. Then the dried tacky agent layer is laminated on the surface of air-transmissible substrate such as a nonwoven fabric made of a synthetic resin to provide the objective tape or sheet suitable as a medical tape.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing a breathable adhesive tape or sheet used for example as a therapeutic tape, and more specifically to a method for forming an adhesive layer. Regarding the improved version.

[Conventional technology]

Adhesive tapes used for medical purposes and the like are required to have appropriate breathability. This is because if the material does not have breathability, it may cause skin irritation.

Therefore, various manufacturing methods have been proposed to provide air permeability to adhesive tapes.

For example, in Japanese Patent Publication No. 51-8653, in the adhesive liquid,
A manufacturing method using a dispersion liquid in which a gas or liquid that is incompatible with an adhesive is dispersed in the form of fine bubbles or liquid bubbles is disclosed. In this method, a dispersion liquid is applied to the surface of release paper so that the thickness is less than 1.2 times the diameter of the air bubbles or liquid bubbles, and the air bubbles or liquid bubbles are broken by heating and drying. is formed.

In addition, in Japanese Patent Publication No. 5B-13116, an adhesive composition using an organic solvent that can be extracted at room temperature with an aqueous coagulated extract is coated on a breathable support, and then immersed in the extract to remove the organic solvent. A method of extracting and coagulating an adhesive composition is disclosed.

In this method, a large number of pores are formed in the adhesive layer by replacing the organic solvent with water.

Furthermore, Japanese Patent Publication No. 63-41585 discloses a dispersion liquid in which water or water and a water-absorbing polymer substance are uniformly dispersed in an organic solvent solution of a rubber-based or acrylic-based bad pressure adhesive.
A method is disclosed in which a release sheet is coated, dried, and then a porous substrate is laminated. In this method, by drying the pressure-sensitive adhesive layer in which water is dispersed, the water prevents the adhesive from fusing, and holes are formed in the areas where the water was present.

However, in the method disclosed in Japanese Patent Publication No. 51-8653 and the method disclosed in Japanese Patent Publication No. 63-41585, gases and liquids that are incompatible with the adhesive are distributed uniformly to form pores. A dispersed dispersion liquid or a dispersion liquid made by uniformly dispersing water or water and a water-absorbing polymer substance must be prepared, and in this dispersion liquid, bubbles, liquid bubbles, water, etc. must be uniformly dispersed. If this condition is not maintained, it is not possible to obtain a breathable adhesive tape with uniformly distributed pores.

As described above, in the conventional manufacturing method for breathable adhesive tapes or sheets, the preparation of the dispersion liquid and the control of the dispersion state are complicated. In addition, there is a demand for something even better in terms of air permeability.

[Problem to be solved by the invention]

Accordingly, an object of the present invention is to provide a manufacturing method that allows an adhesive tape or sheet with even better air permeability to be obtained through relatively simple steps.

[Means to solve the problem]

In order to meet the above-mentioned problems, the inventors of the present invention have applied a pressure-sensitive adhesive solution prepared by dissolving a pressure-sensitive adhesive in an organic solvent onto a release sheet, and then, while the pressure-sensitive adhesive solution is in an undried state, water is added to the pressure-sensitive adhesive solution. We devised a method to form pores in the adhesive layer by spraying it on the surface and drying it. According to this method,
Adhesive tapes or sheets with sufficient air permeability can be obtained through relatively simple steps.

The inventors of the present application investigated ways to further increase air permeability using the above-mentioned novel method for producing air-permeable adhesive tapes or sheets, and as a result, they found that an acrylic adhesive obtained by copolymerizing a macromonomer was used as an adhesive. The present inventors have discovered that it is sufficient to use the following, and have accomplished the present invention.

That is, the present invention includes the steps of preparing an adhesive solution in which an acrylic adhesive obtained by copolymerizing a macromonomer is dissolved in an organic solvent, and applying the adhesive solution onto a release sheet. a step of forming a layer, a step of spraying water on the surface of the adhesive solution layer while it is in an undried state, a step of drying the adhesive solution layer on which water has been sprayed, and a step of drying the adhesive solution layer. and a step of laminating the material with a breathable base material.

The macromonomer used in the present invention has a molecular weight of 1000 to 2000 and has at least one vinyl group.
0 macromonomers are used.

Such macromonomers include polystyrene,
Examples include polymethyl methacrylate-based or polystyrene/acrylonitrile-based macromonomers. More specifically, the product name AS manufactured by Toagosei Chemical Industry Co., Ltd.
-6 (polystyrene macromonomer), trade name AA-6
(polymethyl methacrylate macromonomer) and product name AN6 (polystyrene/acrylonitrile macromonomer), which have a methacryloyl group at the end, are preferably used.

Examples of organic solvents for dissolving the acrylic adhesive obtained by copolymerizing the above macromonomers include toluene, cyclohexane, n-hexani', n-heptane, benzene, iodobenzene, hexadecane, nonylbenzene, nonane, and disulfide. carbon, dodecane, carbon tetrachloride, o, p, m
- Solvents such as xylene, octane or ethylbenzene can be used. In addition, as the organic solvent, not only the pure solvent as mentioned above but also any at least two kinds of organic solvents can be used.
! ! A mixed solvent obtained by mixing solvents may also be used.

As the release sheet, any suitable release sheet that has been conventionally used in the production of adhesive tapes or sheets can be used. Typical examples include release paper or film whose surface has been treated with silicone.

Moreover, when spraying water onto the pressure-sensitive adhesive solution layer on the release sheet, an appropriate spraying device such as a spray gun may be used. When spraying, water droplets having a particle size of about 10 to 1000 μm may be sprayed at a rate of about 5 to 200 g/n.

Drying after spraying is carried out by maintaining the temperature at around 110°C for several minutes. By this drying, water that has entered the adhesive solution layer is dried, and pores are formed in the areas where water was present.

As the breathable base material to be laminated with the dried pressure-sensitive adhesive layer, suitable materials conventionally used in the production of breathable pressure-sensitive adhesive tapes or sheets, such as synthetic resin nonwoven fabrics, etc. can be used.

[Action and effect of invention]

In the present invention, pores are formed in areas where water was present by a simple process of spraying water on the adhesive solution layer and drying it. In other words, preparing a dispersion liquid as in the conventional method,
There is no need for complicated operations such as maintaining a uniform degree of dispersion.

Furthermore, since an acrylic adhesive obtained by copolymerizing a macromonomer is used as the adhesive, pores can be effectively formed. In other words, in the method of creating pores by sprinkling water on an adhesive solution using an organic solvent as a solvent, not only the organic solvent but also the water must be dried, and high temperatures are required for drying.Generally, Synthetic resin adhesives require crosslinking, but crosslinking has not yet occurred sufficiently during the drying process, and the adhesive flows at high temperatures.As a result, the pores formed by the fluidized adhesive become clogged. There is a risk of being exposed.

On the other hand, in the present invention using a macromonomer, the adhesive does not flow even if exposed to a certain high temperature and does not block the pores. Therefore, in the method of forming pores through a relatively simple process as described above, it becomes possible to improve air permeability even more effectively.

The present invention can be applied generally to the production of adhesive tapes or sheets that require air permeability, and is particularly suitable for the production of medical adhesive tapes or sheets.

〔Example〕

Hereinafter, non-limiting examples of the present invention will be described.

Example 1 88 parts by weight of 2-ethyl hequinyl acrylate, 1 part by weight of acrylic acid, 1 part by weight of 2-hydroxyethyl methacrylate, and styrene macromonomer AS-6 (trade name; manufactured by Toagosei Chemical Industry Co., Ltd.) ; 10 parts by weight of a polystyrene macromonomer with a number average molecular weight of 6000 having a methacryloyl group at the end;
An adhesive solution was prepared by polymerizing with cyclohexane and adjusting the solid content to 40%. The viscosity of this solution is 7
000 cps.

Next, the above-mentioned adhesive solution is applied onto release paper at a rate of 100 g/bottom to form an adhesive solution layer, and while the adhesive solution layer is in an undried state, a particle size of 100 g/bottom is applied to the surface of the adhesive solution layer. ~20
Water particles of 0 tIm were sprayed at a rate of 100 g/po, and dried by holding at a temperature of 110° C. for 5 minutes to form an adhesive layer.

Next, this adhesive layer was transferred to a breathable base material (Tetron nonwoven fabric; manufactured by DuPont) to obtain a breathable pressure sensitive adhesive tape.

When the air permeability of the obtained air permeable adhesive tape was measured using a densometer, it took 1.0 seconds for 300 cc of air to pass through.

A monomer composition consisting of 93 parts by weight of 2-ethylhexyl acrylate, 1 part by weight of acrylic acid, 1 part by weight of 2-hydroxyethyl methacrylate, and 5 parts by weight of methyl methacrylate is polymerized with cyclohexane, The solid content was adjusted to 40%. The viscosity of this solution is 70
It was 00cps. To the obtained solution, 0.5 parts by weight of Coronate (manufactured by Nippon Polyurethane Co., Ltd.) was added based on 100 parts by weight of the solid content of the adhesive, and the mixture was sufficiently stirred to prepare an adhesive solution.

Apply the obtained adhesive solution to release paper at 100g/rr? After coating the adhesive solution layer at a ratio of
(spray to a ratio of 11%, then
It was dried for 5 minutes at a temperature of 0°C.

Next, the formed adhesive layer was transferred to a breathable base material (Tetron nonwoven fabric; manufactured by DuPont) to obtain a breathable pressure sensitive adhesive tape.

When the air permeability of the obtained air permeable adhesive tape was measured using a densometer, it took 8.0 seconds for 300 cc of air to pass through.

88 parts by weight of 2-ethylhexyl acrylate, 3 parts by weight of acrylic acid, 0.5 parts by weight of 2-hydroxyethyl methacrylate, 1.5 parts by weight of vinylpyrrolidone, and a macromonomer of polymethyl methacrylate, AA-6(
Product name: Manufactured by Toagosei Chemical Industry Co., Ltd. A monomer composition consisting of 7 parts by weight of polymethyl methacrylate macromonomer (polymethyl methacrylate macromonomer with a number average molecular weight of 6000 having a methacryloyl group at the end) was polymerized with toluene to obtain a solid content of 40%. An adhesive solution was obtained. The viscosity of this adhesive solution was 6000 cps.

After applying the obtained adhesive solution onto a release paper at a rate of 100 g/bottom, while the adhesive solution layer is not dry, water particles having a particle size of 100 to 200 μm are applied to the surface of the adhesive solution layer at a rate of 100 g/r.
It was applied by spraying at a ratio of rr, and then dried at 110°C for 5 minutes.

Furthermore, the formed adhesive layer was transferred to an air-permeable base material (Tetron nonwoven fabric; manufactured by DuPont) to obtain an air-permeable adhesive tape.

When the air permeability of the obtained air permeable adhesive tape was measured using a densometer, it took 1.2 seconds for 300 cc of air to pass through.

Example 3 85 parts by weight of 2-ethylhexyl acrylate, 3 parts by weight of acrylic acid, 0.5 parts by weight of 2-hydroxyethyl methacrylate, 4.5 parts by weight of vinylpyrrolidone, polystyrene/acrylonitrile macromonomer, AN
-6 (trade name manufactured by Nitoa Gosei Kagaku Kogyo Co., Ltd.; a polymethyl/acrylonitrile macromonomer having a methacryloyl group at the end and a number average molecular weight of 6000) 7 parts by weight of a monomer composition consisting of A is polymerized with cyclohexane,
The solid content was adjusted to 30% to obtain an adhesive solution. The viscosity of this adhesive solution was 30QOcps.

Apply 8 liquids of the obtained adhesive onto release paper at 150 g/rr (
Then, while the adhesive solution layer is in an undried state, 1 water particle with a particle size of 100 to 200 μm is added to the surface of the adhesive solution layer in an undried state.
It was sprayed at a rate of 50 g/r+ and dried at 110"C for 5 minutes.

The adhesive layer obtained by drying was transferred to a breathable base material (Tetron nonwoven fabric; manufactured by DuPont) to obtain a breathable pressure sensitive adhesive tape.

When the air permeability of the obtained air-permeable adhesive tape was measured using a densometer, it took 0.5 seconds for 300 cc of air to pass through.

Claims (2)

[Claims] (1) A step of preparing an adhesive solution in which an acrylic adhesive obtained by copolymerizing a macromonomer is dissolved in an organic solvent, and applying the adhesive solution onto a release sheet to form an adhesive solution layer. a step of spraying water on the surface of the pressure-sensitive adhesive solution layer while the pressure-sensitive adhesive solution layer is in an undried state; and a step of drying the pressure-sensitive adhesive solution layer on which the water has been sprayed to form a pressure-sensitive adhesive. A method for producing a breathable adhesive tape or sheet, comprising the steps of: obtaining a layer; and laminating the dried adhesive layer on a breathable base material. (2) As the macromonomer, at least one selected from the group consisting of polystyrene macromonomers, polymethyl methacrylate macromonomers, and polystyrene/acrylonitrile macromonomers having a molecular weight of 1,000 to 20,000 and having at least one vinyl group is used. A method for producing a breathable adhesive tape or sheet as described in .