JPS6122855A - Medical pressure-sensitive adhesive sheet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a medical pressure-sensitive adhesive sheet that is made of polyurethane nonwoven fabric and has excellent elasticity, air permeability, and flexibility. Here, the medical pressure-sensitive sheet is, for example, a sheet or tape used for adhesive bandages, bandages, surgical skin dressings, skin adhesives, and the like.

(Prior Art) A conventional technique for imparting elasticity and breathability to a medical pressure-sensitive adhesive sheet based on a nonwoven fabric includes, for example, creating an emulsion of a pressure-sensitive adhesive elastomer on one side of a porous nonwoven fabric having elasticity. A method of foaming and then coating is described in, for example, Japanese Patent Publication No. 50-4993. Furthermore, a method is described, for example, in JP-A-49-97848, etc., in which a material is impregnated with a liquid that does not dissolve the breathable adhesive component and then laminated with a release paper coated with an adhesive solution. Furthermore, there is also a method of dispersing a non-compatible gas or liquid in the form of fine bubbles in an adhesive liquid, applying it onto a release paper, heating and drying it, and then bonding it to a porous substrate, for example, as described in Japanese Patent Publication No. 51'.
It has been proposed in Publication No.-33811.

(Point Q while the invention is trying to solve the problem) However, the stretchable or porous nonwoven fabric base materials used in these methods are all nonwoven fabrics made of non-elastic materials, so even if they are said to have stretchability, Breaking elongation is at most 10
0%, and once elongated, permanent deformation occurs and it cannot return to its original length, which is an unavoidable drawback. For this reason, when used in areas with strong elasticity, such as in places with strong elasticity, there were problems in that it hindered human movement, or it would lift up from the body as it would be stretched. The object of the present invention is to solve the above-mentioned problems and to provide a medical pressure-sensitive sheet with sufficient elasticity and air permeability, and excellent flexibility.

(Means for Solving the Problems) It is an object of the present invention that melt-spun polyurethane elastic filaments are stacked without being substantially focused, and that the contact points of the stacked filaments are joined by the filaments themselves. This is achieved by using an adhesive sheet made by applying a non-irritating pressure-sensitive adhesive to the skin and having a large number of pores on one side of a polyurethane elastic nonwoven fabric.

As the polyurethane elastomer constituting the nonwoven fabric used in the present invention, known melt-spun thermoplastic polyurethane elastomers are usually low melting point polyols with a molecular weight of 500 to 6,000, such as dihydroxy polyether, dihydroxy polyester, dihydroxy polycarbonate, and dihydroxy polyester. amides, etc., and organic diisocyanates with a molecular weight of 500 or less, such as diphenylmethane diisocyanate, tolylene diisocyanate, inphorone diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate.

2.6-Diycyanate methyl caproate, hexamethylene. It is a polymer obtained by reacting a isocyanate or the like with a chain extender having a molecular ji of 500 or less, such as a glycol, an amino alcohol, or a triol.

Among these polymers, particularly good ones include polytetramethylene glycol or polyε-
It is a polyurethane using caprolactone or polybutylene adipate. When polyethylene glycol is used as a polyol, it improves hydrophilicity and is therefore used for special purposes. In addition, organic diisocyanates include P, P'
-diphenylmethane diisocyanate is preferred. Further, as the chain extender, P,P'-bishydroxyethoxybenzene and 1,4-butanediol are suitable.

The polyurethane elastomer is synthesized from a polyol, an organic diisocyanate, and a chain extender as described above, but in the present invention, polyurethane elastomers are preferably used in which the polyol component accounts for 65% by weight or more of the total weight. Preferably it is 68% by weight or more. When the content of the polyol component is low, the elongation and elongation recovery properties of the resulting nonwoven fabric will be low.

These polyurethane elastomers may contain plasticizers, pigments, stabilizers, and the like.

The nonwoven fabric of the present invention is one in which the constituting polyurethane elastic filaments are spread and laminated over substantially the entire length of the yarn without joining.

If the monofilaments are joined in a bundled state without being opened, the flexibility of the nonwoven fabric will be significantly impaired. The monofilament usually has an average diameter of 30 microns or less, preferably 20 microns or less. The diameter of the monofilament may vary, but it is preferably 50 microns or less at most. When the fiber diameter of the monofilament increases, the nonwoven fabric becomes rough.

The cross-sectional shape of the polyurethane elastic fibers constituting the nonwoven fabric of the present invention can take various shapes such as circular, irregularly shaped, and hollow.
A nonwoven fabric having a circular cross section is preferred from the viewpoint of post-processability, sheet formability, and stretchability.

The nonwoven fabric of the present invention has polyurethane elastic filaments laminated, and the contact points of the fibers constituting the layered body are joined by the fibers themselves.

Such a bonded state can be achieved by thermally fusing the polyurethane elastic fibers together.

The important features of the nonwoven fabric of the present invention are that the nonwoven fabric has extremely high breaking strength and elongation, and has excellent elastic performance. This is because the performance directly reflects the performance of the polyurethane elastic fibers that make up the non-woven fabric, and cannot be obtained with conventional non-woven fabrics made of non-elastic polymers or non-woven fabrics made of polymers with poor elastic performance such as polyester ether elastomers. It has poor performance. The nonwoven fabric of the present invention usually has a breaking elongation of 300.
% or more, preferably 500% or more. The breaking strength is
Although it varies depending on the thickness of the nonwoven fabric, it is usually 0.4 to 9/on, preferably 1.0 to 9/on.

Further, the recovery rate at 100% elongation is usually 85% or more, preferably 90% or more. The strength, elongation, and elongation recovery rate of a nonwoven fabric vary depending on the adhesive strength of the contact points between the fibers that make up the nonwoven fabric, but the nonwoven fabric of the present invention
The above-mentioned strength, elongation and elongation recovery rate indicate that the contact points are sufficiently bonded.

Another feature of the nonwoven fabric of the present invention is that it is extremely flexible. The bending resistance (JISL-1096 45 degree cantilever method) of a nonwoven fabric increases as the basis weight of the nonwoven fabric increases, but the nonwoven fabric of the present invention has a basis weight of X (
! '/m'), and when bending resistance is Y, Y'<0.2X +20, and a preferable range is Y<0.2X+1O. This feature is obtained by combining the physical properties of the polyurethane elastic body with the above-mentioned structure of the nonwoven fabric of the present invention and the small diameter of the constituent fibers. This was something that could not be achieved.

As described above, the nonwoven fabric used in the present invention has sufficiently high elongation and air permeability compared to base materials used for conventional pressure-sensitive adhesive sheets, and has good flexibility and has a right It has the excellent feature of achieving a recovery rate of up to 90%.

These properties allow the adhesive sheet obtained by applying the pressure-sensitive adhesive described below to maintain high air permeability, do not cause rashes or inflammation, and provide sufficient elongation compared to the elongation of the skin. It also helps provide a soft feel.

The basis weight of the nonwoven fabric used in the present invention is 30 to 250 y.
/lri, preferably 50~2゜oy7r
rz is preferred.

This means that when the viscosity of the pressure sensitive adhesive is low, the basis weight of the non-woven fabric is 309/rr? If the basis weight is smaller than 2, it may bleed onto the surface of the base material or the texture may be impaired.
This is because if it is larger than 50 f/lri, the resulting adhesive sheet may lack flexibility and air permeability, or may interfere with body movement.

On the other hand, the pressure-sensitive adhesive used in the present invention may be any pressure-sensitive adhesive as long as it is non-irritating to the skin and non-toxic. Polyisobutylene-based materials can be used as appropriate.

The adhesive liquid containing these adhesive compositions may be either an emulsion type or a solution type, but especially for emulsion type adhesives, a large number of 1411 air bubbles can be removed from the liquid using an appropriate stirrer, such as a Pomo mixer or a lab stirrer. This is preferable because it can be produced in the inside.

As a method for applying these pressure-sensitive adhesives, known techniques such as a knife coating method, a roll coating method, or a roll printing method can be used. It can be printed in a pattern.

Also, by taking advantage of the property of the nonwoven fabric to be easily shaped by heat, the nonwoven fabric is embossed under heat to form a concave and convex pattern on one side of the nonwoven fabric, and only on the top of the convex part. A method of applying adhesive may also be adopted.

Next, the present invention will be explained by examples.

The various physical property values were measured using the following methods.

Breaking strength and elongation: JIS 109 for a 2G width sample
6, the gripping interval was set to 5-1 and the tensile rate was set to 10 times/min, and the strength and elongation per unit at break were measured.

100% elongation turnover rate: A sample with a width of 2σ is elongated to 100% with a gripping interval of 5 and a tensile speed of 10 am/*n, and immediately recovered to the original length at the same speed. The residual elongation rate l (%) was determined from the recorded load-elongation curve and calculated as 100 using the following formula.
Calculate the % elongation recovery rate.

Bending resistance: Based on the 45° cantilever method of JIS L-1096.

Air permeability: JIS L-1096 Frazier type tester was used.

Example 1 554B parts of dehydrated polytetramethylene glycol having a hydroxyl value of 102 (all parts hereinafter refer to parts by weight) and 49B parts of 1,4-bis(β-hydroxyethoxy)benzene
Pour 9 parts into a jacketed kneader and thoroughly dissolve while stirring, then keep at a temperature of 85°C and apply P to the lumps.
, P'-diphenylmethane diisocyanate) 1953N
was added and reacted.

If hV1 stirring is continued, powdered polyurethane is obtained in about 30 minutes, which is formed into pellets using an extruder and has a concentration IP'/10 measured at 25°C in dimethylformamide.
A polyurethane elastomer having a relative viscosity of 250 at 0 cc was obtained.

Using the polyurethane elastomer pellets obtained in this way as a raw material, the nozzles were heated at a melting temperature of 245°C using a melt blow spinning machine having slits for spraying heated gas on both sides of nozzles with diameters of o and sm arranged in a row. Hit 0.1 per minute!
The polymer was discharged at a rate of M, and air heated at 200° C. was injected from the slit at a pressure of 3.5 Kp/ci to atomize it. The thinned filament was collected on a conveyor consisting of a 30-mesh wire mesh installed at 251M below the nozzle, and taken off with a roller to obtain a nonwoven fabric. In this nonwoven fabric, the intertwining points between monofilaments of polyurethane elastic fibers were joined together by fusion. The physical properties of this nonwoven fabric were as follows.

Number of eyes: 50
f/-d tensile strength 0.3
h/am breaking elongation 540%1
00% elongation recovery rate 92% bending resistance
On the other hand, a dispersion system containing a poly(2-ethylhexyl acrylate) emulsion, polyvinyl methyl ether, and a nonionic activator was foamed using a homomixer, and the solid content was 2 (1/2). It was coated on one side of the non-mineralized fabric using a knife coater so that the coating amount was m'.

Thereafter, the adhesive sheet-like product obtained by bag drying at 130°C had the following physical properties.

Tensile strength o, 28 vertical false breaking elongation
510%100% elongation recovery rate
92% bending resistance 52 Chest air permeability 350α Sakaki There was no decrease in air permeability due to expansion and contraction, and there were no symptoms such as rash even after long-term use, and the feel was very good and the feeling of wearing was good. .

Example 2 A polyurethane elastic fiber nonwoven fabric with a date of 1002/G obtained by the same method as in Example 1 was embossed at 130° C. and 10 y/crl using an embossing machine with a dot-shaped roll. Poly(
2-ethylhexyl acrylate) emulsion, 1,5'U Ocp consisting of polyvinyl methyl ether
s adhesive was applied by kiss roll. The printing pressure during application was 10g1rd. The obtained adhesive sheet showed no decrease in air permeability due to expansion and contraction, had the ability to stretch in close contact with the skin, and felt very little resistance at this time. It felt good.

(Effect of the invention) One of the important properties of the adhesive sheet obtained in this way is breathability. In this case, the air permeability is 350cc/cf6ec, and one of the other important properties is that the adhesive sheet according to the present invention uses polyurethane elastic fine leather woven fabric as the base material. Stretchable.

There is something about being flexible.

That is, compared to conventional products, it has sufficient margin for stretching in various parts of the body, such as joints, has less stress during stretching, and can stretch in close contact with the skin. This is a property that cannot be obtained by

In the adhesive sheet according to the present invention, if the basis weight of the polyurethane elastic fiber nonwoven fabric is kept at 250 V/d or less and the thickness of the adhesive layer is kept appropriate, the adhesive can be applied uniformly to one side of the nonwoven fabric. There was no problem of loss of breathability due to expansion and contraction.

As described above, the adhesive sheet according to the present invention has sufficient elasticity and
Since it has a 1 m temperament, it can be applied to various uses such as adhesive bandages, bandages, surgical cloths, etc.

Rikifubo Gosen Co., Ltd.

Claims (3)

[Claims] (1) A large number of pores are formed on one side of a polyurethane elastic fiber nonwoven fabric in which melt-spun polyurethane elastic filaments are laminated without being substantially bundled, and the contact points of the laminated filaments are joined by the filaments themselves. A pressure-sensitive adhesive sheet for medical use is provided with a pressure-sensitive adhesive that is non-irritating to the skin. (2) The bending resistance (Y) of the polyurethane elastic fiber nonwoven fabric is within the range expressed by the general formula Y < 0.2 A sheet according to claim 1. (3) The sheet according to claim 1, wherein the polyurethane elastic fiber nonwoven fabric has a recovery rate of 90% or more at 100% elongation.