JPH0722593B2 - Method for manufacturing breathable adhesive tape or sheet - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a breathable pressure-sensitive adhesive tape or sheet used for medical purposes and other purposes.

(Prior Art) Conventionally, medical adhesive products such as adhesive bandages are used by directly adhering to the human body, but if left in the state for a long time, evaporation of water from the surface of the skin is blocked, Itching and rash occur. Therefore, this can be prevented by providing the pasted product with air permeability. Therefore, many attempts have been made in the past for this purpose.

Among them, for example, there is a method of giving bubbles to the pressure-sensitive adhesive by removing the solvent when the pressure-sensitive adhesive applied to the substrate is dried, to give the pressure-sensitive adhesive microporosity. Kosho
In 63-41585, water or water and a water-absorbing polymer substance are uniformly dispersed in an organic solvent solution of a pressure-sensitive adhesive, and this is coated and dried on the surface of a peelable sheet, and then the coated surface is aerated. A method of stacking base materials made of a flexible material has been proposed.

This method attracts attention as a relatively simple method.

(Problems to be Solved by the Invention) The above method is performed in the adhesive layer applied to the peelable sheet,
When a discontinuous coating film in which water is dispersed is formed and the organic solvent is removed in the next drying step to finally form the adhesive layer, water prevents adhesion of the adhesive and It utilizes the phenomenon that small holes are formed in the portion where water intervenes after evaporation, but when applying the adhesive, for example, if a roll coater method is adopted, the pressure-sensitive adhesive There is a problem that the water dispersed in the organic solvent solution is squeezed out by a roll, and the one containing the necessary water is not applied, and even if such a system that does not cause dehydration occurs, the solvent and water are Is relatively microscopically and uniformly dispersed, there is no difference in evaporation time between the two during coating and drying, and water is likely to evaporate at the same time as the solvent evaporates. There was a problem that it was difficult to do.

The present invention provides a manufacturing method that can easily impart air permeability to a pressure-sensitive adhesive layer regardless of which coating method is used, using water as the above-mentioned conventional technique as a means for imparting air permeability. It was done for the purpose.

(Means for Solving the Problems) 1 of the present invention is an “adhesive layer formed by applying an organic solvent solution of a rubber-based or synthetic resin-based adhesive to the surface of a releasable sheet whose surface has been subjected to a release treatment. Then, while the pressure-sensitive adhesive layer is in the undried state, the particle size of 10 ~
After spraying 5 to 100 g / m ^{2 of} 1000 micron water droplets and drying,
A method for producing a breathable pressure-sensitive adhesive tape or sheet, which comprises transferring the obtained product onto one surface of a breathable substrate "
The second aspect of the present invention is to form a pressure-sensitive adhesive layer by applying an organic solvent solution of a rubber-based or synthetic resin-based pressure-sensitive adhesive to one surface of an air-permeable substrate, and then forming the pressure-sensitive adhesive layer. While the layer is undried, the particle size of 10 ~
The gist is "a method for producing an air-permeable pressure-sensitive adhesive tape or sheet, which comprises spraying 5 to 100 g / m ² of water droplets of 1000 microns and then drying.

Examples of the rubber-based pressure-sensitive adhesive used in the present invention include natural rubber or synthetic rubber, tackifying resins such as rosin-based, terpene-based, and petroleum-based, and softening agents such as various oils dissolved in a solvent such as n-hexane. Examples of the synthetic resin-based pressure-sensitive adhesive used in the present invention include butyl acrylate, 2-ethylhexyl acrylate, and acrylic acid ester such as isononyl acrylate as a main monomer,
This and acrylic acid, acrylamide, N-vinyl-2
An acrylic pressure-sensitive adhesive obtained by copolymerizing a polar monomer such as pyrrolidone or another monomer such as an acrylic acid ester, a methacrylic acid ester, styrene or vinyl acetate is preferably used. Other polyvinyl ether adhesives, polyisobutyl adhesives, etc. can also be used.

And the organic solvent solution of these pressure-sensitive adhesives in the present invention, these pressure-sensitive adhesive components organic solvent, for example, ethyl acetate,
Toluene, Shikurokisan, n- hexane, there is dissolved in the alkane mixture such as the C ₅ -C _7, both known, refers to those already used in the cellophane tape or kraft tape.

Further, the release sheet used in 1 of the present invention may be any material as long as it has a function of releasing the pressure-sensitive adhesive, but the most typical one is so-called release paper treated with silicone. Other examples include steel belts and rotating drums.

The breathable substrate used in the present invention, woven fabric, non-woven fabric,
Examples thereof include paper, cloth, an open-cell foam sheet, or a non-breathable substrate such as a synthetic resin sheet having a large number of fine holes.

In the present invention, as a method of applying the organic solvent solution of the above-mentioned pressure-sensitive adhesive to a peelable sheet or a breathable substrate, various known methods are adopted, for example, a roll coater method, a knife coater method, an extrusion lip. Law etc. are mentioned.

If the breathable substrate used in 2 of the present invention is a woven fabric or the like and has large eyes and the applied adhesive solution easily leaches to the other side, one side of the breathable substrate is previously prepared. A sealing agent such as rubber latex may be appropriately applied to the.

In the present invention, the reason why water droplets are sprayed on the surface of the pressure-sensitive adhesive layer while it is in an undried state is that when the pressure-sensitive adhesive layer is subsequently dried, the portion where the water droplet was present is opened to form a vent hole. The particle size of the water droplets scattered at that time is 10
It should be within the range of up to 1000 microns, and if it is less than 10 microns, it is difficult to form air holes, and even if some holes are formed, the hole diameter is too small and it was laminated on the air permeable base material in a later step. It will be crushed in some cases. If it exceeds 1000 microns, water droplets do not penetrate into the pressure-sensitive adhesive layer, and it is impossible to form a ventilation hole.

Also, application rates of water droplets, must be within the range of 5 to 100 g / m ^2, when the diverging laundry amount is less than 5 g / m ² is insufficient amount of vents, conversely 100 g / If it exceeds m ² , it will take time and energy to dry the sprayed water, and the processing cost will increase.

In the present invention, a spray method is suitable as a method for spraying water droplets on the surface of the pressure-sensitive adhesive layer while the pressure-sensitive adhesive layer is in an undried state, but the means is not particularly limited.

A large number of vent holes are formed in the pressure-sensitive adhesive layer by spraying water droplets and then drying to vaporize the water droplets and the organic solvent.

In the first aspect of the present invention, a breathable pressure-sensitive adhesive tape or sheet is obtained by transferring the above-mentioned pressure-sensitive adhesive layer onto one surface of a breathable substrate by a conventional method. Further, in the second aspect of the present invention, since the above steps are performed on a breathable substrate, a breathable pressure-sensitive adhesive tape or sheet can be obtained by drying.

The breathable pressure-sensitive adhesive tape or sheet produced by the present invention is usually stored and transported as a stack of rolls or cut lengths, but in any case, the pressure-sensitive adhesive does not adhere to the back surface of the substrate. In order to prevent this, the back surface of the base material is used after being subjected to a release treatment, or a release material is interposed between the back surface of the base material and the pressure-sensitive adhesive layer in the state of a roll or a stack.

(Operation) The present invention provides a means for opening a vent hole in the pressure-sensitive adhesive layer by spraying water droplets by spraying water droplets into the pressure-sensitive adhesive layer when the coated surface of the pressure-sensitive adhesive solution is undried. , A relatively macro non-uniform part (a part without a pressure sensitive adhesive) is formed in the pressure sensitive adhesive layer, and after drying, a vent hole is surely formed in a portion where water exists.

(Example) Below, the Example of this invention is demonstrated in detail with a comparative example.

Example 1 100 parts by weight of natural rubber (made in Malaysia; SMR5L) and zinc oxide 5
0 parts by weight and 75 parts by weight of hydrogenated rosin glycerin ester (Hercules Co .; trade name Foral 85) and lanolin 5
Parts by weight and 2 parts by weight of phenyl beta-naphthylamine as an anti-aging agent are added to n-hexane.
It was dissolved in 700 parts by weight to obtain an adhesive solution.

Next, after applying this on a release paper at a rate of 200 g / m ² , while the adhesive solution is undried, water particles with a particle size of 300 to 500 microns become 50 g / m ^{2 on} its surface. It was sprayed and dried.

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

Comparative Example 1 The same adhesive solution as that used in Example 1 was coated on a release paper at a rate of 200 g / m ² , and while the adhesive solution was undried, its surface had a particle size of 300. Water particles of ˜500 μm were sprayed and dried at a rate of 3 g / m ² .

Next, this pressure-sensitive adhesive was transferred to the same breathable base material as used in Example 1 to obtain a breathable pressure-sensitive adhesive tape.

Example 2 Synthetic rubber (manufactured by Zeon Corporation; trade name Quintac) 100
750 parts by weight of an adhesive component consisting of 100 parts by weight of hydrogenated rosin ester (Arakawa Chemical Co., Ltd .; trade name: Ester gum H), 20 parts by weight of process oil, and 5 parts by weight of mercaptobenzimidazole as an anti-aging agent. It melt | dissolved in the part and it was set as the adhesive solution.

Then, this was coated on the air-permeable base material used in Example 1 at a rate of 200 g / m ² , and while the pressure-sensitive adhesive solution was not dried, water particles having a particle size of 500 to 800 microns were formed on the surface thereof. Was sprayed at a rate of 25 g / m ² and dried to obtain a breathable pressure-sensitive adhesive tape.

Comparative Example 2 After the pressure-sensitive adhesive solution used in Example 2 was coated on a breathable substrate at a rate of 200 g / m ^{2 in} the same manner as in Example 2,
While the adhesive solution is undried, the particle size is 500-800 on its surface.
Micron water particles were sprayed and dried at a rate of 150 g / m ² . However, it was observed that still undried water remained on the surface of the pressure-sensitive adhesive layer even after the toluene was dried.

Further, residual water was dried to obtain a breathable pressure-sensitive adhesive tape.

Example 3 A monomer composition consisting of 80 parts by weight of 2-ethylhexyl acrylate, 8 parts by weight of ethyl acrylate, 7 parts by weight of N-vinyl-2pyrrolidone, 4.8 parts by weight of acrylic acid and 0.2 parts by weight of 2-hydroxyethyl acrylate was used as ethyl acetate. Polymerization was carried out and the solid content was adjusted to 30 parts by weight.

Then, this was coated on a release paper at a rate of 150 g / m ² , and while the pressure-sensitive adhesive solution was not dried, a particle size of 100 to 200 was applied to its surface.
Micron water particles were sprayed and dried at a rate of 75 g / m ² .

Next, this pressure sensitive adhesive was transferred to the same breathable base material as used in Example 1 to obtain a breathable pressure sensitive adhesive tape.

Comparative Example 3 The pressure-sensitive adhesive solution used in Example 3 was coated on a release paper at a rate of 150 g / m ² , and while the pressure-sensitive adhesive solution was not dried, water having a particle size of 3 to 8 μm was applied to the surface thereof. The particles were sprayed at a rate of 75 g / m ² and dried.

Next, this pressure sensitive adhesive was transferred to the same breathable base material as used in Example 1 to obtain a breathable pressure sensitive adhesive tape.

The following table shows the observation results (the number of ventilation holes) of the ventilation holes of the breathable adhesive tapes of the above Examples and Comparative Examples by a scanning electron microscope and the results of the ventilation test.

The breathability test is based on the denso meter air permeability (300c
The time required for the air in c to pass through the hole of 6.45 cm ² ) is shown.

(Effect) The present invention provides a means for opening a ventilation hole in the pressure-sensitive adhesive layer as a water drop when the coated surface of the organic solvent solution of the pressure-sensitive adhesive coated on the peelable sheet or the breathable substrate is undried. By adopting a means of spraying, water droplets penetrate into the pressure-sensitive adhesive layer to form a non-uniform portion in the pressure-sensitive adhesive layer, and after drying, a vent hole is surely formed in a portion where water exists. Therefore, there is no restriction on the means for applying the pressure-sensitive adhesive solution to the base material, and the water does not evaporate together with the evaporation of the organic solvent, and the formation of the vent hole using water droplets is easy and reliable. Therefore, a product of excellent quality can be manufactured on an industrial scale.

Claims (2)

[Claims] 1. A pressure-sensitive adhesive sheet is formed by applying an organic solvent solution of a rubber-based or synthetic resin-based pressure-sensitive adhesive to the surface of a release sheet having a release treatment applied thereto, and then the pressure-sensitive adhesive layer is not dried. While in the state, the surface of the pressure-sensitive adhesive layer has a particle size of 10 to 10
A method for producing a breathable pressure-sensitive adhesive tape or sheet, which comprises spraying water droplets of 00 micron in an amount of 5 to 100 g / m ² and then drying, and transferring the obtained product onto one surface of a breathable substrate. 2. A pressure-sensitive adhesive layer is formed by applying an organic solvent solution of a rubber-based or synthetic resin-based pressure-sensitive adhesive to one surface of a breathable substrate, and then while the pressure-sensitive adhesive layer is in an undried state, 5-100g of water droplets with a particle size of 10-1000 microns on the surface of the adhesive layer
/ m ^{2 A} method for producing a breathable pressure-sensitive adhesive tape or sheet, which comprises spraying and then drying.