JPH1112910A - Plaster base fabric for medical application and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a plaster base fabric being thin and soft, excellent in wear resistance, slight in oozing of a tacky material, having elasticity, hardly being steamed. SOLUTION: This plaster base fabric for medical application (i) comprises an elastic nonwoven fabric constituted of randomly arranged elastic short fibers having 0.1-20 μm average diameter composed of an elastomer, (ii) the elastic short fibers are mutually fused at least at one position and (iii) the elastic nonwoven fabric has 0.02-1 mm thickness, >=500 g/m<2> .24 hr moisture permeability and <=90 cc/cm<2> /sec air permeability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical patch base fabric, and more particularly, it is composed of an elastic short fiber made of an elastomer and has excellent ease of application, skin-following property, skin-adhesiveness, and peelability. In addition, a base fabric of a medical patch which has a suitable moisture permeability but does not ooze onto the surface of the pressure-sensitive adhesive and is suitably used for, for example, a percutaneous absorption preparation, a pressure-sensitive adhesive bandage, a bandage, and the like, and production thereof About the method.

[0002]

2. Description of the Related Art Conventionally, as a percutaneous absorption preparation or a bandage, there has been known a medical adhesive material in which a pressure-sensitive adhesive or a laminate of a pressure-sensitive adhesive and a drug is applied to a stretchable base cloth. ing.

[0003] These adhesive materials need to be as thin and sufficiently elastic as possible so as to follow the movement of the body without discomfort when applied to the skin. Films and non-woven fabrics have been proposed for base fabrics and sheets as a backing material for adhesives, but they have good breathability and little friction, and have excellent tactile sensation on the back side of the adhesive layer application surface when pasted. Non-woven fabrics are preferred. For example, as disclosed in Japanese Patent Publication No. 1-48019, the fiber sheet is made to have a certain range of elongation and elongation / recovery ratio as compared with a conventional card web, thereby providing a better fit to the skin. Something with enhanced feeling and flexibility has been proposed. However, in order to further reduce discomfort with the skin, it is essential to reduce the thickness of the patch. The disadvantage that the agent oozes out to the back side surface was inevitable.

In order to solve such a disadvantage, Japanese Patent Laid-Open Publication No.
JP-A No. 1126 proposes a sheet material in which the diameter of the fiber constituting the sheet base material is reduced to not only soften the texture but also improve the exudation of the pressure-sensitive adhesive. When the fibers are made extremely fine, the fiber strength is also reduced, which causes a problem that the back surface of the pressure-sensitive adhesive layer-coated surface becomes fuzzy due to friction during sticking and used, which is undesirable in appearance. The above publication also discloses a method of partially bonding the nonwoven sheet, but the unbonded portion is left,
It is difficult to achieve both the exudation of the adhesive and the problem of abrasion.

On the other hand, Japanese Patent Application Laid-Open No. 7-16257 proposes a method of fusing a printing surface to a nonwoven fabric sheet made of ultrafine fibers as a method for improving wear resistance, which is made of ultrafine fibers. There is a problem in that when the sheet is greatly stretched, a feeling of resistance is generated, and a sense of incongruity at the time of mounting is increased, and the thickness of the sheet is increased.

[0006]

The present invention not only reduces exudation of the pressure-sensitive adhesive to the back surface and reduces abrasion resistance, but also gives an uncomfortable feeling when applied to skin that is thin, excellent in flexibility and stretchability. It is an object of the present invention to provide a medical patch base fabric made of ultrafine fibers having a low content and a method for producing the same.

[0007]

Means for Solving the Problems In order to improve the drawbacks of the medical patch base fabric, the present inventors have specified a non-woven fabric made of an elastomer and made of elastic short fibers having a specific fiber diameter. It has been found that a base fabric capable of achieving the above-mentioned object can be obtained by heat-sealing by the method described above.

That is, according to the present invention, (i) an elastic nonwoven fabric in which elastic short fibers composed of an elastomer and having an average diameter of 0.1 to 20 μm are randomly arranged;
(Ii) the elastic short fibers are fused to each other at at least one place; and (iii) the elastic nonwoven fabric has a thickness of 0.02 to 1 mm and a moisture permeability of 500 g / m ² · 24 hr or more. And a medical patch base fabric having a gas permeability of 90 cc / cm ² / sec or less.

According to the present invention, there is also provided a medical patch base fabric as described above, wherein the elastic non-woven fabric is produced by an elastomer melt-blowing method, and the obtained non-woven fabric is thermocompression-bonded with a heating roller. A manufacturing method is provided. Hereinafter, the medical patch base fabric and the method for producing the same according to the present invention will be described in more detail.

The elastic fibers constituting the elastic nonwoven fabric used in the present invention are composed of an elastomer, and the elastomer has rubber elasticity such as a polyester elastomer, a polyurethane elastomer, a polyolefin elastomer, a polyamide elastomer, and a polystyrene elastomer. Any type of thermoplastic elastomer can be used, but polyester elastomers are preferred from the viewpoint of thermal stability during melt molding of elastic fibers and heat treatment of the fabric.

As the polyester-based elastomer, a block copolymer comprising a polyester hard segment having crystallinity and a flexible soft segment comprising at least one selected from polyether or polyester is generally used. In the polyester constituting the hard segment, 50 mol% or more, preferably 70 mol% or more of the acid component is terephthalic acid or an ester-forming derivative thereof, or 2,6-naphthalenedicarboxylic acid or an ester-forming derivative thereof, and a diol component. 50 mol% or more, preferably 70 mol% or more of 1,4-
Polybutylene terephthalate-based polyester or polybutylene naphthalate-based polyester obtained by polycondensation of a component unit that is butanediol or an ester-forming derivative thereof is preferably used because of its high crystallization rate. That is, the hard segment is preferably a crystalline aromatic polyester segment.

The dicarboxylic acids other than terephthalic acid or 2,6-naphthalenedicarboxylic acid include isophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, and 4,4'-diphenyldicarboxylic acid. Aromatic dicarboxylic acids such as diphenylsulfone dicarboxylic acid, diphenoxyethane dicarboxylic acid, diphenyl ether dicarboxylic acid, methyl terephthalic acid and methyl isophthalic acid; aliphatics such as succinic acid, adipic acid, sebacic acid, decane dicarboxylic acid and dodecane dicarboxylic acid Examples thereof include alicyclic dicarboxylic acids such as dicarboxylic acid and cyclohexanedicarboxylic acid, and these may be used alone or in combination of two or more.

Examples of the diol other than 1,4-butanediol include ethylene glycol, trimethylene glycol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, and 1,4-cyclohexanedimethanol. These may be used alone or in combination of two or more. Further, the crystalline polyester is in a range that does not impair the crystallinity of the polymer (for example, 20 mol% or less, preferably 10 mol% or less).
In the following, some of these may be replaced with polyesters composed of other carboxylic acids such as oxycarboxylic acids such as ε-oxycaproic acid, oxybenzoic acid and hydroxyethoxybenzoic acid.

Such an acid component and a diol component include:
Each of these may be used alone or in combination, but the crystalline polyester constituting the hard segment has an intrinsic viscosity of 0.6 to 2.0 and a melting point of 120 ° C or more (preferably 150 ° C or more). The temperature is desirably 280 ° C or lower (preferably 220 ° C or lower). When the intrinsic viscosity is less than 0.6, the melt-moldability of the obtained copolyester is greatly reduced, and the performance as a nonwoven fabric is also poor. Conversely, if the intrinsic viscosity exceeds 2.0, the melt-kneading temperature must be set high during the production of the copolymerized polyester, which is not preferable from the viewpoint of thermal degradation of the polyester.

On the other hand, the soft segment is preferably a polyether ester in which the diol component is composed of polyalkylene glycol or a polyester composed of a polyester described later. Examples of the polyalkylene glycol include polyoxyethylene glycol, polyoxypropylene glycol, polyoxytrimethylene glycol, polyoxytetramethylene glycol and copolymers thereof, and among them, polyoxytetramethylene glycol is particularly preferred. The molecular weight (number average) of these polyalkylene glycols may be in the range of 300 to 10,000, but preferably 500 to 5,000 in terms of fiber elasticity and heat resistance during molding. preferable.

As the acid component of the polyetherester, the dicarboxylic acid used for forming the above-mentioned hard segment may be used. At that time, the ratio of the polyalkylene glycol in the finally obtained polyetherester type block copolymer elastomer is 30 to 30%.
When it is in the range of 90% by weight, preferably in the range of 40 to 80% by weight, more preferably in the range of 50 to 70% by weight, the balance between the elongation, the elastic recovery and the 50% elongation stress of the nonwoven fabric and the moldability are compatible. Is done.

The above polyetherester type block copolymer elastomer can be obtained by a method well known per se, that is, by subjecting a dicarboxylic acid derivative, an alkylene diol, or a polyalkylene diol to interesterification, followed by a polymerization reaction. Can be.

On the other hand, when a polyester ester block copolymer using a soft polyester as a soft segment is used as the nonwoven fabric raw material polymer, the polyester constituting the soft component is a polycaprolactone-based aliphatic polyester or the following (I) Polyesters that simultaneously satisfy the requirements of (1) to (III) are preferably used. (I) The aliphatic dicarboxylic acid component having 4 to 20 carbon atoms occupies 0 to 50 mol% based on the total acid component of the polyester constituting the soft segment. (II) The aromatic dicarboxylic acid component having 8 to 16 carbon atoms occupies 50 to 100 mol% based on the total acid component of the polyester constituting the soft segment. (III) The aliphatic diol compound having 3 to 20 carbon atoms occupies 50 to 100 mol% based on all diol components of the polyester constituting the soft segment. Here, the aliphatic dicarboxylic acid component (I) has 4 carbon atoms.
If it is less than 1, the number of carbon atoms existing between carboxyl groups is small, so that the obtained block copolymerized polyester is susceptible to hydrolysis and has poor thermal stability during melt spinning. Conversely, if the number of carbon atoms exceeds 20, the aliphatic dicarboxylic acid is not preferable because it has problems such as high cost and difficulty in obtaining it.
The preferred number of carbon atoms is 7 to 15. Aliphatic dicarboxylic acids that can be preferably used include, for example, succinic acid, adipic acid, speric acid, sebacic acid, decanedicarboxylic acid, dodecanedicarboxylic acid, dimer acid, cyclohexanedicarboxylic acid, isophthalic acid, ester-forming derivatives thereof, and the like. These may be used alone or in combination of two or more.

The copolymerization ratio of the aliphatic dicarboxylic acid (I) is from 0 to 50 mol% based on the total acid components of the polyester constituting the soft segment. From the viewpoint, the copolymerization ratio is preferably 5 to 30 mol%.

Next, the aromatic dicarboxylic acid component having 8 to 16 carbon atoms (II) accounts for 50 to 100 mol%, preferably 70 to 95 mol%, based on the total acid component of the polyester constituting the soft segment. Is preferred. This aromatic dicarboxylic acid component, without reducing the hydrolysis resistance of the soft segment polyester, heat resistance, in order to function as a soft segment in the obtained block copolymerized polyester, for the purpose of reducing the crystallinity described above. It must occupy a percentage. As this kind of aromatic dicarboxylic acid component, terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyldicarboxylic acid and the like are preferable.

The aliphatic diol compound (III) having 3 to 20 carbon atoms preferably occupies 50 to 100 mol% based on all diol components of the polyester constituting the soft segment. If the number of carbon atoms is less than 3, the number of repeating structural units per unit weight increases, and the hydrolysis resistance is poor. Conversely, when the carbon number exceeds 20, the reactivity is lacking. When the amount of the aliphatic diol component is less than 50 mol%, the flexibility of the copolymerized polyester is insufficient.

Such diol compounds include propylene glycol, tetramethylene glycol, 1,5
-Pentanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, trimethylpentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, 1,9-nonanediol, 3,3-
Examples thereof include dimethyl-1,5-pentanediol, octamethylene glycol, decamethylene glycol, dodecamethylene glycol, and ester-forming derivatives thereof. Among them, those having an alkyl group in a side chain are particularly preferable in order to reduce the crystallinity of the soft segment. Of course, the above diol compounds may be used alone or in combination of two or more. Further, in order to increase flexibility, the above-mentioned polyalkylene glycol may be mixed as needed.

Further, the intrinsic viscosity of the polyester alone constituting the soft segment is preferably in the range of 0.6 to 1.0. If this intrinsic viscosity is less than 0.6,
The melt-moldability of the obtained block copolymerized polyester is greatly reduced, and the performance as a nonwoven fabric is further deteriorated. Conversely, if the intrinsic viscosity exceeds 1.0, the melt-kneading temperature must be set high during the production of the block copolymerized polyester, which is not preferable from the viewpoint of thermal degradation of the polymer.

This type of polyester ester type block copolymer elastomer can be obtained by melt-kneading the above-mentioned polyester constituting the hard segment and the polyester constituting the soft segment and causing a block reaction. At this time, the respective copolymerization ratios (weight ratios) in the blocking reaction were defined as (polyester constituting the hard segment) :( polyester constituting the soft segment) = (10-70) :( 9
It is advantageously in the range of 0 to 30). The copolymerization ratio of the polyester constituting the hard segment is 10% by weight.
If it is less than the above, the number of hard segments in the obtained block copolymerized polyester is too small, so that not only heat resistance, molding workability, workability in the production of the nonwoven fabric, etc. are lowered, but also the elongation stress of the nonwoven fabric becomes insufficient. On the other hand, if it exceeds 70% by weight, the elongation elastic recovery of the block copolymerized polyester becomes insufficient. The blocking reaction may be performed by any of a batch method and a continuous method. For example, a method in which each polyester component is individually subjected to a polycondensation reaction to a desired intrinsic viscosity, and then mixed to perform a blocking reaction. Can be mentioned.

The elastomer of the present invention has a glass transition point (Tg) of -70 ° C to 10 ° C, preferably -20 ° C to 10 ° C.
Desirably, it is 10 ° C. The value of Tg is less than -70 ° C,
In particular, when the temperature is lower than -20 ° C, the rubber elasticity of the polymer is developed at a low temperature, so that the stress when the base fabric is stretched is increased and the feeling of tightening, the feeling of discomfort is increased, and when applied to the skin,
It is not preferable because the end of the base fabric is easily rounded. on the other hand,
If the Tg exceeds 10 ° C., the rubber elasticity may be insufficient, and the base fabric may become hard or may not exhibit sufficient elasticity. Of course, the elastomer may contain a flame retardant and, if desired, additives such as a chain extender, a filler, an antioxidant, and a lubricant.

The average diameter of the elastic fibers constituting the elastic nonwoven fabric of the present invention must be 0.1 to 20 μm. Fiber diameters less than 0.1 μm are difficult to obtain,
Process stability during fiber formation is also low. If it exceeds 20 μm, the voids between the fibers become too wide, which may cause bleeding after application of the pressure-sensitive adhesive even by the heat-sealing treatment of the fabric of the present invention described later. In addition, the diameter mentioned here means that when the cross section of the elastic fiber is irregular (for example, elliptical, multi-lobal, polygonal, etc.),
It means the diameter when they are regarded as a round section having a corresponding thickness (denier).

Elastic fibers having a fiber diameter within this range can be obtained by a melt blow method. Melt blow method
Usually, a molten polymer is discharged from a large number of spinning holes arranged side by side in the width direction of a die such as a T-die, and at the same time, a high-temperature and high-speed gas flow is discharged from slits provided on both sides of the die. This is a method of obtaining a sheet-like material by depositing a group of ultrafine fibers formed by thinning the obtained polymer on a moving air-permeable collecting surface. According to this method, fine fibers can be easily obtained, and the molten polymer can be directly formed into a sheet. Therefore, the nonwoven fabric of the thermoplastic elastomer can be most preferably obtained.

The yarn forming conditions will be described in more detail. The polymer has a melt viscosity of 100 poise to 3000 poise, and more preferably 500 poise to 20 poise.
It is less than 00 poise. If the melt viscosity is too low, thread breakage is likely to occur, and at the same time, polymer balls are likely to be generated, and the uniformity of the fiber diameter is also deteriorated. On the other hand, if the melt viscosity is too high, it is difficult to reduce the fiber diameter.

[0029] The spinning temperature of the polymer is the melting point of the polymer +
[10 ° C. or higher and 100 ° C. or lower] is preferable, and it is preferable to lower the viscosity at a temperature as high as possible within a range where the polymer is not thermally decomposed and a process condition is stable. If the temperature is too high, the melt viscosity increases, which is not preferable. If the temperature is too high, thermal decomposition is liable to occur, and the long-term operation stability decreases.

The high-temperature and high-pressure gas for drawing and thinning the discharged polymer is preferably air or water vapor. If the temperature of the traction gas is too far from the spinning temperature of the polymer, the temperature of the discharged polymer will be affected.
0 ° C.] or less, more preferably [Polymer spinning temperature +
(10 to 50 ° C)]. Further, the gas flow rate may be appropriately determined depending on the target fiber diameter, the discharge amount, and the bonding state. At this time, although it depends on the width of the jet slit of the gas flow, a preferable flow rate is 0.01 to 0.2 Nm ³ per 1 cm of the base width.
/ Min. 0.01 nm ³ / min smaller than thinning does not proceed sufficiently, also increases plaques of the resulting nonwoven fabric, 0.2 Nm ³
If it exceeds / min, the fiber breakage will be excessively large depending on the slit width and the discharge amount, which is not preferable.

The fiber group discharged and drawn down by the high-temperature and high-pressure gas is deposited on a collecting surface such as a net having a suction, and is obtained as a sheet-like material, that is, a nonwoven fabric. In this case, it is preferable that the distance between the lower surface of the base and the collecting surface is lower than the position where the fibers are solidified, so that the fibers do not adhere to each other more than necessary and the texture of the nonwoven fabric does not become coarse and hard. If the collecting surface is located too low, the fiber flow is disturbed by the jet gas flow and the accompanying flow, and the fibers are entangled in a bundle and cause unevenness of the nonwoven fabric. The preferable distance between the lower surface of the base and the collection surface is suitably 10 to 80 cm.

Further, in the medical patch base fabric of the present invention, it is necessary that the fibers are fused to each other at at least one place, and that the thickness of the elastic nonwoven fabric is 0.02 to 1 mm. That is, the elastic nonwoven fabric obtained by the melt blow method has low abrasion resistance as it is, and after application of the adhesive,
It is conceivable that the adhesive oozes out to the back surface. In addition, the thickness of the base fabric must be reduced in order to reduce the feeling of discomfort when applied to the skin. When the thickness is less than 0.02 mm, it becomes difficult to sufficiently prevent the bleeding of the pressure-sensitive adhesive, and the handleability as a patch becomes poor. On the other hand, if the thickness is more than 1 mm, the elastic fibers are sufficiently compressed by a normal thermocompression bonding method using a heating roller, and it is easy to prevent the exudation of the pressure-sensitive adhesive. It is unavoidable that an uncomfortable feeling at the time of pasting increases, and the end of the pasting material is easily caught during attachment, for example, being caught. A preferable thickness range is 0.05 to 0.5 mm.

In the present invention, in order to obtain an elastic nonwoven fabric which is excellent in abrasion resistance, does not exude to the back side of the pressure-sensitive adhesive, and has the performance of being thin, the elastic nonwoven fabric comprising the elastic nonwoven fabric is formed by the following method. The step of thermocompression bonding the fibers is essential. That is, in order to fuse the fibers over the entire surface of the elastic non-woven fabric obtained by the melt blowing method, one of the pressure rollers is heated to a metal roller having a flat or embossed pattern, and the roller forming the pair is paper or rubber. For example, a roller made of a material having elasticity is used. Alternatively, a metal or elastic roller having a heated metal emboss roller and a concave portion corresponding to the convex portion of the emboss pattern is used. When both use a metal roller, both may be heated or only one may be heated. The method of thermocompression bonding using a combination of a heated metal roller having an embossed pattern and an elastic roller is preferably used because unevenness is attached to the fabric and friction resistance at the time of mounting is reduced. It is important to leave the fiber form to some extent without completely turning it into a film. When the film is completely formed, the abrasion resistance is improved. However, depending on the basis weight of the fabric, the strength is increased, the followability is deteriorated, and the moisture permeability is also lost.

In order to maintain the performance of preventing the pressure-sensitive adhesive from oozing to the back side of the thermocompressed fabric, the air permeability is 90 cc / cm.
cm ² / sec or less (JIS L1096). On the other hand, in order to ensure moisture permeability, the moisture permeability is 500 g / m ² · 24 hr (JIS Z0208).
It is necessary to be above. Air permeability is 90cc / cm ² / s
If the temperature exceeds ec, the drug oozes out and the moisture permeability becomes 50
If it is less than 0 g / m ² · 24 hr, it may cause stuffiness when applied to the skin. The air permeability is 1 to 50 cc / cm ² /
sec, moisture permeability is 1000-2000 g / m ² ·
It is preferably in the range of 24 hours. The embossed pattern may be any of dots, streaks, short rectangles, etc., but a dot-shaped pattern is preferred since frictional resistance is easily reduced.

Although the temperature of the heating roller depends on the linear pressure between the rollers, it is lower than the melting point of the thermoplastic elastomer constituting the elastic fiber, preferably from [melting point-120] ° C. to [melting point-
30 ° C]. If the temperature is too low, the fibers do not fuse together sufficiently, and if the temperature is too high, the fabric is fused or shrunk to the rollers, resulting in poor process stability and undesired discoloration. The linear pressure is preferably 2 to 15 N / cm. In processing, it is preferable from the viewpoint of thermal stability of the fabric that the temperature be as low as possible and the linear pressure be as high as possible within a range where the elastic short fibers are fused together.

The medical patch base fabric of the present invention also comprises
The stress at 0% elongation is preferably from 10 to 500 g / cm. If the stress at 50% elongation is less than 10 g / cm, the handling at the time of mounting becomes inferior, and 500 g / cm
cm, the stress at the time of elongation is too large, and the feeling of discomfort at the time of wearing becomes large. Preferably it is 20 to 200 cm.
Further, the 50% elastic recovery is 80% or more, preferably 90%.
% Is desirable in order to ensure the ability to follow the skin. It is preferable that the elongation of the base fabric is at least 200% or more from the viewpoints of handleability and skin followability when applied. A practical elongation of 220 to 600% is practical.

The basis weight (nonwoven fabric) of the present invention is 5 to 20.
It is preferably in the range of 0 g / m ² . 5g / weight
When it is less than m ² , it is too thin and handling becomes difficult. On the other hand, when it exceeds 200 g / m ² , it becomes too thick and the elongation stress becomes too high, so that discomfort may be increased.
Further, the progress of the nonwoven fabric is preferably 100 to 600%. If the elongation is less than 100%, the release paper may be broken when peeling off at the time of sticking, while if it exceeds 600%, it may be unnecessarily elongated and difficult to peel off from the release paper. .

The medical patch base fabric of the present invention is used as a medical patch by applying an adhesive layer on at least one surface. The pressure-sensitive adhesive layer is preferably a coating layer having excellent gas permeability. Preferred pressure-sensitive adhesives constituting the pressure-sensitive adhesive layer include acrylic pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives,
A silicone-based pressure-sensitive adhesive, a gel-type pressure-sensitive adhesive, or the like is used, and is appropriately selected depending on the purpose of use. That is, when using this patch as a transdermal absorption preparation, an adhesive may be selected so that the drug is most effectively absorbed from the skin and the skin is less irritating. Further, the pressure-sensitive adhesive layer may contain a transdermally absorbable drug depending on the application.

As a method for providing the above-mentioned pressure-sensitive adhesive layer on the adhesive base fabric, the pressure-sensitive adhesive is applied directly to the base material, or the pressure-sensitive adhesive layer is formed on release paper, and the release paper is used as a base. Conventional methods such as a method of transferring the pressure-sensitive adhesive layer onto a material can be appropriately selected and employed. In the application method, the pressure-sensitive adhesive layer is applied on the entire surface of one side of the patch base fabric or partially, for example, in a streak-like, mesh-like, or dotted pattern. Usually, a knife over roll coater is used for applying the pressure-sensitive adhesive to the substrate, but other methods may be adopted. The thickness of the pressure-sensitive adhesive layer is 0.01 to 2 mm, preferably 0.015 to 1 mm.

When the adhesive-coated base fabric is used as a medical patch, a separator is usually provided on the adhesive surface to protect the surface of the pressure-sensitive adhesive layer until use.
As the separator, a polyethylene terephthalate film obtained by siliconizing is often used,
The separator is not limited to this. The thickness of the separator is 0.1 mm or less, preferably 0.005 to 0.05 mm.

[0041]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto. In the examples, "parts" indicates parts by weight, and each physical property value was measured by the following method.

(1) Average Short Fiber Diameter The diameter of 100 short fibers was calculated from the cross section of the nonwoven fabric from an electron micrograph of × 500 and calculated by averaging. (2) Thickness The thickness was measured with a Peacock type thickness gauge at a load of 0.012 N / cm ² . (3) 50% elongation stress and elongation The 50% elongation stress and elongation of the nonwoven fabric in the longitudinal direction (the flow direction of the collection net) and the lateral direction (the width direction of the collection net) were measured as follows. After making a rectangular sample piece of 8 cm length and 2.5 cm width from the non-woven fabric, the short pieces of the two opposing sides are respectively gripped with chucks, the distance between the chucks is set to 5 cm, and the stretching speed is 200% / min. The stress (g / cm) at the time of elongation by 50% based on the chuck interval was determined, and the elongation (%) at the time of elongation and breakage of the sample piece was determined. (4) 50% elastic recovery rate With a chuck interval of 5 cm, an elongation speed of 20 in the long side direction.
After extending the sample length by 50% with respect to the sample length at 0% / min, and setting the interval to the sample length L (7.5 cm), the same chuck speed as the stretching speed is maintained without maintaining the state. I put it back. Immediately after that, the nonwoven fabric is stretched again, and the sample length when the stress starts to become larger than 0 is L'cm.
Was calculated by the following equation. 50% elongation elastic recovery (%) = (LL ′) / (L−
5) × 100 (5) Air permeability Measured at 124 Pa using a method according to JIS L1096. (6) Moisture Permeability Using a method according to JIS Z0208, the moisture permeability was measured according to 40 ° C. and 90% relative humidity. (7) Abrasion resistance After two days had passed with the affixed to the wrist, the appearance of fluff was visually determined and evaluated as follows. ○ indicates no fluffing △ indicates slight fluffing X indicates fluffing (8) Method for measuring Tg A polymer is heated and melt-pressed to a width of 5 mm and a thickness of 0.5.
mm film, and the Tg of the film was measured at a frequency of 10 Hz using a Leo Vibron (model DDV-01125FP manufactured by Orientec Co., Ltd.). )

Example 1 167 parts by weight of dimethyl terephthalate, 105 parts by weight of tetramethylene glycol, and 325 parts by weight of polytetramethylene glycol having a number average molecular weight of 2,000 were subjected to transesterification in a reactor, and the internal temperature was raised to 245 ° C. Warm, 20m
The reaction was carried out under a weak vacuum of maq for 60 minutes, followed by 0.4
The reaction was performed under high vacuum of mmaq for 200 minutes. The obtained block copolymer of polyester and polyetherester had a melting point of 190 ° C. and an intrinsic viscosity of 1.52. The glass transition point (Tg) of this elastomer is -6
It was 0 ° C.

The copolymer was heated at 115 ° C. under a reduced pressure of 1 mmHg.
And melted at 260 ° C. by a melt blow method, and then heated to 280 ° C. after discharging by using a die having a round cross-section with a single row of discharge holes arranged at 1 mm intervals in the width direction of the die. The compressed air thus obtained was stretched and thinned at a flow rate of 0.06 Nm ³ / min per 1 cm width of the die, and then collected on a collection net provided 25 cm below the die. The average short fiber diameter of the obtained nonwoven fabric is 7 μm
Met. Furthermore, this nonwoven fabric is subjected to a depth of 1 at 40 mesh.
An elastic nonwoven fabric having a basis weight of 20 g / m ² was obtained by pressing a metal roller with a 150 mmφ metal roller having a 20 μm square dot pattern and an NBR roller having a hardness of A75 at 150 ° C. and a linear pressure of 5 N / cm. Table 1 shows the physical properties of the obtained nonwoven fabric.

Examples 2 to 4 and Comparative Examples 1 to 3 Non-woven fabrics of various fibers were obtained from the same polymer as in Example 1 by melt-blowing in the same manner as above with different discharge rates.
The speed of the collecting net was changed with the same fiber diameter as in Example 1 to obtain nonwoven fabrics having various basis weights. These nonwoven fabrics were subjected to pressure bonding under the same conditions as in Example 1 to obtain an elastic nonwoven fabric. Table 1 shows the physical properties.

Example 5 Melt blowing was performed under the same conditions as in Example 1, and the obtained nonwoven fabric was rolled with a metal roller 8 using a flat metal roller having a diameter of 150 mmφ and a paper roller having a hardness of D73 degrees.
Table 1 shows the physical properties of the elastic nonwoven fabric obtained by pressure bonding at 0 ° C. and a linear pressure of 12 N / cm.

Comparative Example 4 Melt blowing was performed under the same conditions as in Example 1, and the obtained nonwoven fabric was flat-rolled with a 200 mmφ upper and lower diameter metal roller at a roller temperature of 160 ° C. and a linear pressure of 3N.
Table 1 shows the physical properties of the elastic nonwoven fabric obtained by pressure bonding at a pressure of / cm.

Example 6 194 parts by weight of dimethyl terephthalate, 162 parts by weight of tetramethylene glycol and 0.15 part by weight of titanium tetrabutoxide were charged into a transesterification reactor, and heated to 190 ° C. in a nitrogen gas atmosphere to produce The transesterification reaction was carried out while flowing out methanol to the outside of the system.
After the transesterification, polycondensation was carried out at 230 ° C. under reduced pressure to obtain a polybutylene terephthalate-based polyester polymer having an intrinsic viscosity of 1.07 and a melting point of 223 ° C.

On the other hand, 136 parts by weight of dimethyl isophthalate, 62 parts by weight of dimethyl sebacate and 180 parts by weight of 1,6-hexanediol were added to 0.1 part of dibutyltin acetate.
The mixture was heated together with 3 parts by weight to remove by-product methanol from the reaction system. The reaction product is transferred to a reaction vessel capable of
The reaction was carried out at 55 ° C. under reduced pressure to obtain an amorphous polyester having an intrinsic viscosity of 0.80.

The above-mentioned polybutylene terephthalate-based polyester and this amorphous polyester were mixed in a weight ratio of 35:65.
At an internal temperature of 240 under reduced pressure of 1 mmHg.
After reacting at 50 ° C. for 50 minutes, 0.2 parts by weight of phenylphosphonic acid was added as a catalyst deactivator, and the mixture was further stirred for 10 minutes to completely stop the blocking reaction. The intrinsic viscosity of the obtained polyester ester block copolymer was 1.15 and the melting point was 205 ° C. The glass transition point (Tg) of this elastomer was −10 ° C.

The copolymer was heated at 120 ° C. under a reduced pressure of 1 mmHg.
And melted at 270 ° C. by a melt blow method, and after discharging under the same conditions as in Example 1, the polyester is stretched and thinned by pressurized air heated to 300 ° C., and then a nonwoven fabric is formed on a collection net. As a supplement. The average fiber diameter of the obtained nonwoven fabric was 8 μm. The obtained nonwoven fabric was subjected to pressure bonding under the same conditions as in Example 1 except that the temperature of the metal roller was set to 155 ° C., to obtain an elastic nonwoven fabric.
Table 1 shows the physical properties of the obtained elastic nonwoven fabric.

[0052]

[Table 1]

The thickness of the pressure-sensitive adhesive layer after drying a 10 wt% ethyl acetate solution of a copolymer of 2-ethylhexyl acrylate, butyl methacrylate and acrylic acid (weight ratio 90 / 7.5 / 2.5) on release paper Was 50 μm, and the pressure-sensitive adhesive layer was dried.

As shown in Table 1, fibers having a fiber diameter within the range of the present invention and pressed by a predetermined method have low air permeability and excellent abrasion resistance. I have. Those having a thickness outside the range of the present invention as in Comparative Examples 2 and 3 have the abrasion resistance, and the elastic nonwoven fabric having the thickness was obtained by transferring the adhesive layer thus obtained to the elastic nonwoven fabric shown in Table 1. Then, it was cut into a width of 1 cm and a length of 4 cm, attached to the second joint of the index finger for 16 hours, and tested for seepage of the adhesive. As Comparative Examples 1 and 2 shown in Table 1, those having high air permeability and high moisture permeability confirmed the exudation of the pressure-sensitive adhesive. In Comparative Example 3, neither exudation nor fluffing of the pressure-sensitive adhesive was observed, but since the stress at the time of elongation was high and the thickness as the adhesive material was large, the feeling of discomfort when attached was large. In Comparative Example 4, since the metal rollers were used on both the upper and lower sides when the elastic nonwoven fabric was pressed, fusion between the fibers became insufficient, and oozing of the adhesive and fuzzing were observed. No oozing of the pressure-sensitive adhesive was observed in any of the examples, and the product was easily produced on the skin and could be suitably used as a patch.

[0055]

The medical patch base fabric of the present invention has elasticity exhibited by the elastic short fibers constituting the base fabric, and softness exhibited by the small diameter and the thinness of the fabric, and Because the elastic short fibers are fused to some extent over the entire surface of the fabric, they have excellent abrasion resistance, and when an adhesive layer is applied,
Bleeding of the pressure-sensitive adhesive to the backside of the pressure-sensitive adhesive layer is also prevented while ensuring moisture permeability. Therefore, when applied to the skin as a medical patch, there is no discomfort, it does not easily fall off during wearing, it has excellent appearance, it has various characteristics that it is not stuffy, transdermal absorption preparations, adhesive bandages, It is suitably used for bandages and the like.

Claims (4)

[Claims] 1. An elastic nonwoven fabric comprising (i) an elastic short fiber composed of an elastomer and having an average diameter of 0.1 to 20 μm, which is randomly arranged, and (ii) the elastic short fibers are mutually fused in at least one place. And (iii) the elastic non-woven fabric has a thickness of 0.02 to 1 mm and has a thickness of 500 g /
m ² · 24 hr or more, and 90 cc /
A medical patch base fabric having an air permeability of not more than cm ² / sec. 2. The medical patch base fabric according to claim 1, wherein the elastomer is a polyester elastomer. 3. The medical patch base fabric according to claim 1, wherein the elastomer has a glass transition point of -70 to 10 ° C. 4. The method according to claim 1, wherein the elastic nonwoven fabric is produced by an elastomer meltblowing method, and the obtained nonwoven fabric is thermocompression-bonded by a heating roller.
The manufacturing method of the medical patch base fabric according to the above.