JPH07133469A - Production of air-permeable adhesive product - Google Patents

Abstract

PURPOSE:To simply produce the product excellent in air permeability and adhesion and suitable for medical treating materials such as adhesive plasters by coating the surface of an air-permeable substrate with a specific adhesive dispersion and subsequently drying the coated dispersion to dispose an adhesive layer having many opened holes on the substrate. CONSTITUTION:(A) The side or both the sides of a substrate having air permeability, such as a (non)woven fabric or knitted fabric, is coated with (B) an acrylic adhesive dispersion, and subsequently dried to obtain the product in which an adhesive layer having many opened holes has been disposed. The acrylic adhesive dispersion is obtained by homogeneously dispersing a solvent type acrylic adhesive containing a hydrophobic solvent such as toluene and a non-hydrophobic organic solvent such as ethyl acetate in a weight of 100-85:0-15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a breathable adhesive product which is preferably used mainly for medical purposes.

[0002]

2. Description of the Related Art Medical adhesive products such as adhesive bandages, bandages, and surgical cloths are often used by directly sticking them to the human body, but if they are stuck for a long time, water vaporization from the skin surface may occur. It may cause itching and rashes.
Heretofore, as a countermeasure against this, it has been carried out to make the adhesive product for medical use breathable. For example, in a rubber-based or acrylic solvent-based adhesive, water or water and a water-absorbing polymer substance are uniformly dispersed. A method has been proposed in which a coating film of this dispersion liquid is provided on a porous substrate to provide air permeability (Japanese Patent Publication No. Sho 6).
However, in the case of this method, a high level of breathability is not always obtained and the method is not sufficiently practical.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a simple method for producing a breathable adhesive product having a high level of breathability in order to solve the above-mentioned conventional problems.

[0004]

The method for producing a breathable pressure-sensitive adhesive product of the present invention is a method for producing a pressure-sensitive adhesive product in which a pressure-sensitive adhesive layer is provided on one side or both sides of a breathable substrate. Acrylic solvent obtained by uniformly dispersing water in an acrylic solvent-based pressure-sensitive adhesive containing a hydrophobic organic solvent and a non-hydrophobic organic solvent in a weight ratio of 100 to 85: 0 to 15 as an agent It is characterized in that a pressure-sensitive adhesive dispersion is used, and the dispersion is applied and dried to form a large number of openings in the pressure-sensitive adhesive layer, whereby the above object is achieved.

The type of breathable base material used in the breathable adhesive product according to the production method of the present invention is not particularly limited, but may be woven fabric, non-woven fabric, knit, open-cell plastic foam or the like. Various breathable materials are preferably used.

The acrylic solvent-based pressure-sensitive adhesive used in the breathable pressure-sensitive adhesive product according to the production method of the present invention comprises a hydrophobic organic solvent and a non-hydrophobic organic solvent in a weight ratio of 100 to 85: 0 to 1.
Various (meth) acrylic acid alkyl esters such as (meth) acrylic acid ethyl ester, (meth) acrylic acid propyl ester, (meth) acrylic acid butyl ester, and (meth) acrylic acid 2-ethylhexyl ester using a solvent of No. 5 A monomer as a main component, and these monomers and (meth) acrylic acid, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl acrylate, N-methylol (meth) acrylamide, glycidyl methacrylate, vinyl acetate, A monomer such as styrene or acrylonitrile is used as a polymerization catalyst using a peroxide such as benzoyl peroxide or lauroyl peroxide under a nitrogen reflux at 60 to 8%.
It is obtained by a copolymerization reaction at a temperature of about 0 ° C. for about 6 to 10 hours.

The hydrophobic organic solvent used as the main solvent of the acrylic solvent-based pressure-sensitive adhesive means an organic solvent having a solubility in water at 25 ° C. of 1% by weight or less, and specifically, toluene and normal hexane. , Cyclohexane, etc., but toluene is more preferably used considering the boiling point, vapor pressure and the like.

In the present invention, it is necessary to use a hydrophobic organic solvent as the main solvent of the acrylic solvent type adhesive,
It is not always necessary to use only the hydrophobic organic solvent. A non-hydrophobic organic solvent such as ethyl acetate or butyl acetate may be used in an appropriate amount within a range that does not hinder the dispersion of water.
However, the ratio is limited to 15% by weight or less.

The breathable pressure-sensitive adhesive product according to the production method of the present invention uses an acrylic pressure-sensitive adhesive dispersion obtained by adding and dispersing water to an acrylic solvent-type pressure-sensitive adhesive, and the dispersion is used as a breathable base material surface. Or apply it to a release material surface such as release paper,
After drying to form a pressure-sensitive adhesive layer having a large number of pores, it can be obtained by laminating it with a release material when applied to the base material surface, or with a breathable base material when applied to the release material surface. However, generally, a method is preferred in which it is applied to the surface of the release material, dried, and then laminated with a breathable substrate to transfer the pressure-sensitive adhesive layer having pores to the substrate.

The amount of water added to the acrylic solvent-based pressure-sensitive adhesive is not particularly limited, but is preferably about 5 to 80 parts by weight of water with respect to 100 parts by weight of the acrylic solvent-based pressure-sensitive adhesive solution, and among them, 20 It is more preferably about 40 parts by weight.

If the amount of water added is less than about 5 parts by weight relative to 100 parts by weight of the acrylic solvent-based adhesive solution, the pressure-sensitive adhesive layer will have insufficient openings and sufficient air permeability cannot be obtained.
On the contrary, if the amount of water added is more than 80 parts by weight based on 100 parts by weight of the acrylic solvent-based adhesive solution, water will be excessively present, and the resulting adhesive layer will lack continuity or be non-uniform. Therefore, good adhesive performance cannot be obtained.

The coating amount of the above acrylic pressure-sensitive adhesive dispersion on the air-permeable substrate varies depending on the application and is not particularly limited, but a film thickness after drying is preferably about 10 to 100 μm.

If the coating amount of the acrylic pressure-sensitive adhesive dispersion on the air-permeable substrate is less than about 10 μm in the film thickness after drying, it becomes difficult to obtain the desired adhesive performance, and conversely, the acrylic pressure-sensitive adhesive is difficult to obtain. The coating amount of the dispersion is 100μ in terms of the film thickness after drying.
If it exceeds about m, excessive coating may result in the openings of the pressure-sensitive adhesive layer being crushed, resulting in poor air permeability and high cost.

The drying conditions for coating and drying the above acrylic pressure-sensitive adhesive dispersion on the surface of the substrate or the release material are not particularly limited, but ordinary drying equipment such as a multi-stage zone dryer is used. Drying may be performed under the conditions of 50 to 150 ° C. for 3 to 10 minutes.

When the drying is carried out under the above-mentioned conditions, especially at the initial stage of the drying, it is desirable to keep the drying air velocity of the drying equipment at about 5 m / sec or less. By suppressing the drying air velocity, the hydrophobic organic solvent is preferentially evaporated, and the viscosity of the acrylic pressure-sensitive adhesive dispersion on the coated surface increases. As a result, the water particles dry without being crushed, so that sufficient openings are formed in the pressure-sensitive adhesive layer, and a breathable pressure-sensitive adhesive product having excellent air permeability can be obtained. More desirably, the drying air velocity in the initial stage of drying is suppressed to about 5 m / sec or less, and the drying air velocity in the middle drying period and the latter period of drying is increased to about 10 m / sec, so that the drying time can be shortened without crushing the openings of the adhesive layer Can be done.

[0016]

The breathable adhesive product produced by the method of the present invention is an acrylic solvent containing a hydrophobic organic solvent and a non-hydrophobic organic solvent as an adhesive in a weight ratio of 100-85: 0-15. An acrylic pressure-sensitive adhesive dispersion obtained by dispersing water is used as the die-type pressure-sensitive adhesive, and a pressure-sensitive adhesive layer having a large number of openings obtained by coating and drying the dispersion is provided on a breathable substrate. Since it is provided, it exhibits a high level of breathability.
In addition, this manufacturing method does not require special raw materials or equipment,
This is an extremely simple method.

[0017]

EXAMPLES In order to explain the present invention in more detail, examples will be given below. In addition, "part" in an Example means a "weight part."

(Example 1)

(A ) In a reaction vessel equipped with a polymerization thermometer for an acrylic solvent-based pressure-sensitive adhesive , a stirrer and a nitrogen inlet tube, as shown in Example 1 in Table 1, 150 parts of toluene and 2-acrylic acid were added. Ethylhexyl ester 95 parts, acrylic acid 3 parts and polymer monomer "Chemlink C-4500"
2 parts (manufactured by US Sartomer Co., Ltd.) were charged, 0.06 part of benzoyl peroxide was further added, and the polymerization reaction was carried out at 80 ° C. for 8 hours while stirring under nitrogen reflux to obtain an acrylic solvent-based pressure-sensitive adhesive.

( B) Preparation of Acrylic Pressure-Sensitive Adhesive Dispersion To 250 parts of the obtained acrylic solvent-based pressure-sensitive adhesive, 5 parts of water was added.
0 part was added and stirred to obtain an acrylic pressure-sensitive adhesive dispersion.

( C) Preparation of Breathable Adhesive Product The resulting acrylic pressure-sensitive adhesive dispersion is dried on the release-treated surface of a release paper that has been subjected to a release treatment with a silicone-based release agent to give a film thickness after drying. The adhesive layer having a large number of openings was provided by coating and drying so as to have a thickness of 35 μm. The drying conditions at this time were 100 m C for 5 minutes at a wind speed of 2.5 m / sec. Then
A rayon-based non-woven fabric DM-3882 (basis weight: 32 g / m ² , manufactured by Dexter Miki Co., Ltd.) is used as a breathable base material, and a breathable pressure-sensitive adhesive product is laminated with a pressure-sensitive adhesive layer having a large number of openings provided on the release paper. Got

( D) Evaluation Table 1 shows the results of evaluation of the adhesive strength and air permeability of the obtained breathable adhesive product by the following methods.

Adhesive strength : According to JIS Z-0237 "Adhesive tape / adhesive sheet test method", a breathable adhesive product cut into a width of 20 mm and a length of 150 mm has a thickness of 1.5 m.
m, width 20 mm, length 150 mm, bonded to a cold-rolled stainless steel plate with an adhesion length of 100 mm, 23 ° C.-65
After being left in an atmosphere of% RH for 20 minutes, a 180 ° angle peel strength (g / 20 mm) was measured at a tensile speed of 300 mm / min using a Tensilon tester. In addition, the acceptance standard of the adhesive strength was a peel strength of 800 g / 20 mm or more.

Air permeability : In accordance with JIS P-8117 "Paper and board air permeability test method", the time required for 300 ml of air to pass through a breathable adhesive product having an area of 645 mm ² (second / 300 ml). Was measured. In addition, the acceptance standard of air permeability was 10 seconds / 300 ml or less.

(Comparative Example 1)

In the polymerization of acrylic solvent-based adhesive,
As shown in Comparative Example 1 in Table 1, an acrylic pressure-sensitive adhesive dispersion was obtained in the same manner as in Example 1 except that the solvent composition was a mixed solvent of 100 parts of toluene and 50 parts of ethyl acetate. Using the obtained acrylic pressure-sensitive adhesive dispersion, a breathable pressure-sensitive adhesive product was obtained in the same manner as in Example 1 at a drying air velocity of 2.5 m / sec.

The adhesive strength and air permeability of the obtained breathable adhesive product were evaluated in the same manner as in Example 1 and the results are shown in Table 1.

(Comparative Example 2)

The same acrylic adhesive dispersion as used in Comparative Example 1 was used to prepare a breathable adhesive product in the same manner as in Comparative Example 1 except that the air velocity during drying was 10 m / sec. To obtain a breathable adhesive product.

The adhesive strength and air permeability of the obtained breathable adhesive product were evaluated in the same manner as in Example 1 and the results are shown in Table 1.

(Examples 2-3, Comparative Examples 3-4)

As shown in Example 2, Example 3, Comparative Example 3 and Comparative Example 4 in Table 1, four kinds of acrylic adhesive dispersions having different solvent compositions were obtained. Four kinds of breathable adhesive products were obtained in the same manner as in Example 1 by using the obtained four kinds of acrylic adhesive dispersions and drying at a wind speed of 2.5 m / sec.

The results of evaluating the adhesive strength and air permeability of the four types of breathable adhesive products obtained in the same manner as in Example 1 are shown in Table 1.
It was as shown in.

(Comparative Example 5)

The same acrylic adhesive dispersion as used in Comparative Example 3 was used to prepare a breathable adhesive product in the same manner as in Comparative Example 3 except that the air velocity during drying was 10 m / sec. To obtain a breathable adhesive product.

The adhesive strength and air permeability of the obtained breathable adhesive product were evaluated in the same manner as in Example 1 and the results are shown in Table 1.

[0037]

[Table 1]

[0038]

As described above, the breathable pressure-sensitive adhesive product produced by the method of the present invention has excellent breathability and pressure-sensitive adhesive performance, and is mainly suitable for medical use. Further, the production method of the present invention does not require special raw materials or equipment and provides the above-mentioned breathable adhesive product very simply.

Claims (1)

[Claims] 1. A method for producing an adhesive product comprising an air-permeable base material and an adhesive layer provided on one or both sides thereof, wherein a hydrophobic organic solvent and a non-hydrophobic organic solvent are used as the adhesive. Acrylic pressure sensitive adhesive dispersion obtained by uniformly dispersing water in acrylic solvent type pressure sensitive adhesive which is contained so as to have a ratio of 100-85: 0-15 is applied and dried. A method for producing a breathable pressure-sensitive adhesive product, which comprises providing a large number of openings in the pressure-sensitive adhesive layer.