JP2696543B2 - External material - Google Patents

Description

The present invention relates to an external material used for wound dressing and the like, which requires air permeability and moisture permeability in the field of medical hygiene, and particularly relates to a porous plastic. Emergency bandage, large bandage, formed by providing a pressure-sensitive adhesive layer on one side of the base material
The present invention relates to an external material suitably used for a dressing material, a drape material, and the like.

(B) Conventional technology Conventionally, pressure-sensitive adhesive sheets used for medical applications such as adhesive plasters cause rash and stuffiness when applied to the outer skin for a long period of time, so that air permeability and moisture permeability are required to prevent this. In addition, flexibility is required to smoothly follow the movement of the application site such as a joint.

By the way, a plastic film such as polyurethane or polyvinyl chloride has been mainly used as a plastic substrate used for this kind of external material.

(C) Problems to be Solved by the Invention However, polyurethane films are expensive, and when the thickness is large, moisture permeability and air permeability are significantly reduced, and as a result, rash and stuffiness occur. For this reason, when a polyurethane film is used as a plastics base material for external materials, it is necessary to reduce the thickness to 40 μm or less, but this significantly reduces the strength, loses self-supporting properties, and poses a problem in handling. Occurred.

In addition, since polyvinyl chloride itself does not have air permeability, it is usually provided with air permeability or moisture permeability by providing a large number of small holes using a punch. In the obtained product, the gap between the holes is large, and air permeability and moisture permeability are performed only in the perforated part of the small hole, and most of the other parts are not air permeable. It has the drawback that it is difficult to apply.

In addition, when a large number of small holes are formed by using a drilling machine in this way, the diameter of each small hole is large, and water permeates from the small hole portion, and the periphery of the small hole is easily peeled, and bacteria enter. It also had drawbacks such as ease.

The present invention has breathability and moisture permeability throughout,
In addition, the present invention provides an external material that is excellent in followability to the skin and has little unpleasant sensation such as a tight feeling even when attached to the skin.

(D) Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the problems of the above plastics base material, and as a result, formed a porous plastic base material with a polyolefin resin. using specific porous plastic substrate, moreover the moisture permeability used more than 300g / m ² · 24hr when provided with a pressure-sensitive adhesive layer on one side of the particular porous plastic substrate, Completed the present invention by finding that it has good air permeability and moisture permeability, has no problems such as rash and stuffiness, has excellent followability to the skin, and has no discomfort such as stickiness when attached to the skin. That is what led to it.

That is, the external use material of the present invention has a porous plastic base material made of a polyolefin resin having a tensile strength of 100 to 500 kg / c.
m ² , elongation percentage is 50% or more, 20% modulus is in the range of 25 to 100 kg / cm ² , and the moisture permeability when a pressure-sensitive adhesive layer is provided on one surface of the porous plastic base material is 300 g / m ² -It is characterized by being longer than 24 hours.

 Hereinafter, the present invention will be described in detail.

Examples of the polyolefin resin used in the present invention include polyethylene resin, polypropylene resin, ethylene-vinyl acetate copolymer resin and the like.
In particular, the production and use of linear low-density polyethylene resin
It is desirable because of its excellent workability and low production cost.

The polyolefin resin may be used alone, but may be used in combination of two or more, such as a combination of a polyethylene resin and an ethylene-vinyl acetate copolymer resin. The substrate may be composed of one layer, or may be composed of two or more layers of the same type or different types.

Among the above-mentioned polyolefin-based resins, a linear low-density polyethylene resin is particularly preferred because it is excellent in production and processability of the porous plastic base material and its production cost is low.

The linear low-density polyethylene resin is a copolymer of ethylene and an α-olefin, and examples of the α-olefin include butene, hexene, and octene.

The above-mentioned polyolefin-based resin includes a resin blended with a filler, if desired. Examples of the filler include calcium carbonate, talc, clay, kaolin, silica, barium sulfate, kaolin sulfate, aluminum hydroxide, and zinc oxide. , Calcium oxide, titanium oxide, alumina, mica, bentonite and the like.

The filler has an average particle size of 30 μm or less, preferably in the range of 0.1 to 10 μm.

If the particle size is too large, the through-holes will be large, and if too small, aggregation will occur and the dispersibility will be poor, which is not preferable.

The mixing ratio of the polyolefin resin (A) and the filler (B) is such that (B) is 50 to 4 with respect to 100 parts by weight of (A).
Desirably, the amount is 00 parts by weight.

If the above (B) is too small, less than 50 parts by weight, the air permeability and the moisture permeability will be reduced, and when it is applied to the skin, it will become stuffy, causing whitening of the skin and problems of skin irritation. On the other hand, if the above (B) exceeds 400 parts by weight, kneadability and moldability deteriorate, and the film strength also decreases. Therefore, it is particularly desirable that the blending ratio of (B) is in the range of 100 to 300 parts by weight based on 100 parts by weight of (A).

A porous plastic substrate is formed using the above-mentioned polyolefin-based resin, and examples of the production method include the following.

A sheet formed of a polyolefin resin is directly formed by uniaxial stretching or biaxial stretching or a porous substrate is obtained by stretching, and then a filler or an organic substance soluble in an acid, alkali or water is eluted. Formed
Further, a sheet obtained by forming a mixed composition of a polyolefin-based resin and a solvent into a sheet and then evaporating the solvent (solvent method) may be used.

In this case, the polyolefin-based resin sheet may be formed by using a usual molding apparatus and molding method. In particular, an inflation molding machine, a T-die molding machine, and the like are suitably used. Or, it is biaxially stretched to form a porous plastics substrate, and this stretching method may be performed by a usual method using a usual stretching apparatus, for example, roll stretching, simultaneous biaxial stretching, sequential biaxial stretching. Stretching or the like is employed.

Among the above-mentioned porous plastic substrates, the porous plastic substrate formed by the solvent method is desirably prepared by a stretching method because the influence of the residual solvent on the skin can be considered.

The sheet may be formed in a thickness of usually 50 to 1000 μm in accordance with the method considered to be the best in extrusion molding or inflation molding.
To be in the range of ~500kg / cm ^2, the uniaxially or biaxially, and the following polyolefin resins melting point, preferably in the range of 15 to 30 ° C. below the melting point, 5 times or less, preferably 1.
It is important that the film be stretched in a range of 1 to 3.5 times and be porous.

If the stretching ratio is less than 1.1, the stretched portion and the unstretched portion coexist, and the stretching becomes uneven.
If it exceeds twice, it is not preferable because it may break during stretching.

In the present specification, the stretching ratio refers to the width or length after stretching with respect to the width or length of the sheet before stretching.

After the porous plastic substrate is stretched in the uniaxial or biaxial direction, heat treatment may be performed to stabilize the sheet dimensions or to obtain a uniform substrate having no variation in air permeability and moisture permeability. For example, if a polyolefin-based resin sheet is stretched four times and then heat-treated to reduce the stretching ratio to two times, a more uniform base material can be obtained than the one stretched twice from the beginning.

In addition, the porous plastic substrate may be subjected to a surface corona treatment in order to enhance anchoring with a pressure-sensitive adhesive layer described later.

Further, a heat stabilizer, an ultraviolet stabilizer, a pigment, and the like can be added to these porous plastic substrates as required.

By the way, the porous plastic substrate used in the present invention has flexibility to follow the skin, has little discomfort such as a feeling of tightness when applied to the skin, and smoothly moves the attached site such as a joint. It is necessary to design so that it can follow.

In other words, the required properties of the external material are that it be sufficiently adhered to the skin, but also flexible enough to follow the movement of the skin when applied to the joints and bent parts of the human body. You. For this reason, the external material adhered to the human body cannot follow the deformation due to the expansion and contraction of the skin if the elastic modulus of the porous plastic base material is too low, and gives a mechanical stimulus such as a sense of tension to the skin, or It is easy to peel off from the skin.

Therefore, it is desirable to impart a suitable elasticity to the porous plastics substrate, a low-melting polymer,
Although a method of adding a rubber-like substance and a plasticizer has been proposed, in the present invention, EPR, EPT, etc. are used as means for providing an external material having excellent followability to the skin and less discomfort such as tension. It is desirable to add the ethylene-propylene rubber-like elastic composition to the polyolefin resin.

The ethylene-propylene rubber-like elastic composition is not particularly limited as long as the rubber-like substance has a number average molecular weight of 5,000 to 800,000, and specific representative examples include ethylene and α-. Olefin and a cyclic or non-cyclic copolymer having a non-conjugated double bond (hereinafter referred to as EP
DM).

EPDM is ethylene, propylene or butene-1
And terpolymers comprising the polyene monomers listed below, wherein the polyene monomers include dicyclopentadiene, 1,5-cyclooctanediene, 1,1-cyclooctadiene, 1,6-cyclododecadiene, 7-cyclododecadiene, 1,5,9-cyclododecatriene, 1,4-cycloheptadiene, 1,4-cyclohexadiene, 1,6-heptadiene, norbornadiene, methylene norbornene, ethylidene norbornene, 2-methylpentadiene- 1,4,1,5-hexadiene, methyl-tetrahydroindene, 1,4-hexadiene and the like.

The copolymerization ratio of each monomer is preferably
Mooney viscosity ML with a terpolymer of ~ 80 mol%, polyene 0.1 ~ 20 mol%, and the remainder being α-olefin
_{1 + 4} (temperature 100 ℃) 1 ~ 60 is good.

The ratio of the ethylene-propylene-based rubbery composition (C) to the polyolefin-based resin (A) is as follows.
(C) is 5 to 150 parts by weight with respect to parts by weight, and particularly preferably the mixing ratio of (C) is 10 to 80 parts by weight.

In the above mixing ratio, if (C) is too small, less than 5 parts by weight, it does not have sufficient elasticity to follow the expansion and contraction of the skin, and if it exceeds 150 parts by weight, the kneading property deteriorates and surface unevenness occurs. Therefore, neither is preferable.

In the porous plastics base material, an ethylene-propylene rubber-like elastic composition 10 to 80 parts by weight with respect to 100 parts by weight of a polyolefin resin, and a sheet-like molded product comprising 100 to 300 parts by weight of a filler are stretched. It is desirable that the formed article has more excellent air permeability and moisture permeability, and that an external material having excellent resilience to the skin can be obtained.

The porous plastic substrate has a tensile strength of 100-500 kg
/ cm ² , elongation 50% or more, 20% modulus 25-100kg / c
m ² , it is easy to follow the movement of the skin, but the tensile strength exceeds 500 kg / cm ² and the elongation percentage is 50% or less.
If the 0% modulus exceeds 100 kg / cm ² , the strength of the sheet-like base material is too strong to follow the movement of the skin, giving an uncomfortable feeling or mechanical irritation, which is not preferable. On the other hand, tensile strength is 100k
If the g / cm ^{2 is} less than 20% and the modulus is less than 25 kg / cm ^{2, the} substrate becomes too flexible and handling becomes inconvenient.

In the present invention, as the pressure-sensitive adhesive layer applied to one surface of the porous plastic substrate, various pressure-sensitive adhesives such as natural rubber, polyisoprene, polyvinyl ether, and polyacrylate are used. The formed layer can be used.

As the pressure-sensitive adhesive layer used in the present invention, a material that is less irritating to the skin of the pressure-sensitive adhesive itself, has excellent adhesiveness, is highly breathable, and is preferably a material having high moisture permeability.From these viewpoints,
In particular, a copolymer of an acrylic acid or methacrylic acid alkyl ester monomer and a carboxyl group-containing copolymerizable monomer is preferred.

As described above, the reason for using the acrylic acid or methacrylic acid alkyl ester monomer (D) is that this material has no strong irritation to the skin, has excellent moisture permeability even when used for a long time, and has a reduced adhesiveness. Is unlikely to occur.

It is particularly preferable to use a material obtained by copolymerizing a carboxyl group-containing copolymerizable monomer (E) with an alkyl ester monomer (D) of acrylic acid or methacrylic acid because the former (D) alone has a cohesive strength. In contrast, when the latter (E) can be copolymerized, a suitable cohesive force can be obtained, the skin adhesion is excellent, and the problem of so-called "residual residue" does not occur.

It is desirable that such a copolymer has a glass transition point of 250 ° K or lower, preferably 180 to 250 ° K, and a weight average molecular weight of 50,000 or more, preferably 500,000 to 2,000,000.

If the glass transition point exceeds 250 ° K, appropriate adhesiveness and cohesive strength cannot be obtained.

Also, if the weight average molecular weight is less than 50,000, an appropriate cohesive force cannot be obtained.

It is practically more preferable that the amount of the copolymer is set in the range of 1 to 10 parts by weight with respect to 100 parts by weight of the former (D).

In this mixing ratio, if (E) is less than 1 part by weight, the cohesive force is relatively weak, while if it exceeds 10 parts by weight, the cohesive force becomes unnecessarily high and a large amount of polar groups are introduced. This is because, when affixed to the skin, there may be a problem of skin irritation.

The thickness of the pressure-sensitive adhesive layer is desirably 10 to 60 μm. If the thickness of this layer is less than 10 μm, sufficient adhesiveness to adhere to the skin cannot be obtained, while if it exceeds 60 μm, sufficient moisture permeability cannot be obtained even with the above-mentioned copolymer. On the other hand, when the thickness is 10 to 60 μm, both adhesiveness and moisture permeability are excellent.

Examples of the alkyl ester monomer of acrylic acid or methacrylic acid of the copolymer include ethyl acrylate, propyl acrylate, butyl acrylate, isooctyl acrylate, isononyl acrylate, decyl acrylate, lauryl acrylate, and methacrylic acid thereof. Esters are used, and these can be used alone or in combination of two or more.

As the carboxyl group-containing copolymerizable monomer, acrylic acid, methacrylic acid, itaconic acid, maleic acid and the like are used.

Further, together with the above monomer mixture, a vinyl monomer can be used if necessary.

In producing this pressure-sensitive adhesive, a normal polymerization catalyst, for example, an azobis compound or a peroxide can be used. As the polymerization method, any polymerization method such as solution polymerization, emulsion polymerization, and suspension polymerization is employed. it can.

For example, acrylic acid, acrylic acid alkyl ester monomer, a monomer mixture such as the copolymerizable vinyl monomer, a solvent such as ethyl acetate, and a radical generating catalyst in a reaction vessel, The polymerization is completed in 10 to 20 hours.

The overall moisture permeability 300g / m ² · 24hr or more in a stacked state to the above consists of a polyolefin resin such as a porous plastic substrate and the pressure-sensitive adhesive layer, preferably 300～2000G /
it is desirable to set to m ² · 24hr.

Amount of perspiration from human skin are individual differences, depends area of skin, there is a possibility that moisture permeability can not be sufficiently permeable to water vapor at high sites perspiration is less than 300g / m ² · 24hr, stuffiness and rash like This is because there is a danger.

 The transmittance was measured by the following method.

10 ml of distilled water is placed in a glass container having an inner diameter of 38 mm and a height of 40 mm, and an external material having a diameter of 50 mm is fixed and sealed over the mouth of the container with its pressure-sensitive adhesive layer facing downward.

Next, this is placed in a thermo-hygrostat at a temperature of 40 ° C. and a relative humidity of 30% and left for 24 hours.

 Then the amount of water loss from this container is measured.

The moisture permeability at this temperature of 40 ° C. is expressed as g / m ² · 24 hr.

In producing the external material of the present invention, the pressure-sensitive adhesive is directly applied to a porous plastic base material made of a polyolefin resin, dried, and a peelable sheet is formed on the exposed surface of the pressure-sensitive adhesive layer thus obtained. (Paper) or by applying the above-mentioned pressure-sensitive adhesive on a releasable sheet (Paper), drying, and then bonding a porous plastic substrate. As a result, an external material in which the pressure-sensitive adhesive layer is protected by a peelable sheet (paper) can be obtained.

(E) Function The external material of the present invention has the above-mentioned structure, and uses a specific porous plastic substrate formed of a polyolefin resin as the porous plastic substrate, that is, the porous plastic substrate has a tensile strength. 100 to 500 kg / cm ² , elongation percentage of 50% or more, 20% modulus in the range of 25 to 100 kg / cm ² , and the permeability when a pressure-sensitive adhesive layer is provided on one side of this specific porous plastic substrate Uses a material with a humidity of 300 g / m ² or more, so it has good air permeability and moisture permeability, has no problems such as rash and stuffiness, and has excellent follow-up properties to the skin. This has the effect of eliminating the sense of strangeness.

(F) Example Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto.

 In the following, parts mean parts by weight.

(A) Production of porous low-density polyethylene resin porous plastic substrates (I to VII) Linear low-density polyethylene resin (MI2.0, density 0.93),
EPDM (trade name, EPT9720, Mitsui Petrochemical Co., Ltd.) as a rubber-like substance, and calcium carbonate (average particle size 2
μm, fatty acid treatment), stearic acid as a lubricant,
The components were mixed in the proportions shown in the table, mixed and stirred sufficiently, and the mixture was sufficiently kneaded with a twin-screw kneader (TEM-50, manufactured by Toshiba Machine Co., Ltd.) to produce a composition obtained by an ordinary method. Granulate.

This composition was melted and formed into a film by a 65 mmφ inflation extruder to produce films having the thicknesses shown in Table 1 respectively.

The film thus obtained is subjected to uniaxial stretching (substrates I to VI) by a roll stretching machine or biaxial stretching (substrate VII) by a sequential biaxial stretching method. A plastic substrate was manufactured.

At this time, the stretching conditions include a stretching temperature of 60 ° C. and a stretching speed.
6m / min, stretching ratio is changed by changing the speed ratio of the roll.
Each was adjusted so as to become the value of Table 1.

Table 1 shows the properties of each of the porous plastic substrates thus obtained.

Note 1) The methods of measuring elongation (MD) and 20% modulus (MD) shown in Table 1 are as follows.

The elongation percentage was measured by a tensile test (Tensilon VTM-IIIL, manufactured by Orientec Co., Ltd.) on a base material having a length of 100 mm and a width of 20 mm at a tensile speed of 300 mm / min at a gauge distance (distance between chucks) of 50 mm. Measure the SS curve. In this measurement, the elongation (%) when the sample breaks is referred to, and the strength at 20% elongation is expressed as 20% modulus. The strength at break is expressed as MD.

Note 2) The moisture permeability shown in Tables 1 to 3 was measured by the following method.

10 ml of distilled water is placed in a glass container having an inner diameter of 38 mm and a height of 40 mm, and an external material having a diameter of 50 mm is fixed over the mouth of the container with its pressure-sensitive adhesive layer facing downward.

Next, this is placed in a thermo-hygrostat at a temperature of 40 ° C. and a relative humidity of 30% and left for 24 hours.

 Then the amount of water loss from this container is measured.

The moisture permeability at a temperature of 40 ° C. is expressed as g / m ² · 24 hr.

(B) Production of pressure-sensitive adhesive layer (A) 97 parts of butyl acrylate 3 parts of methacrylic acid 150 parts of ethyl acetate 0.3 part of azoisobutyronitrile 0.3 parts of the above components were charged in a polymerization reactor, and the inside of the reactor was purged with nitrogen. Stir while stirring.

Thereafter, the internal bath temperature was maintained at 55 to 65 ° C., and polymerization was started. The polymerization is completed in about 10 hours.

Thereafter, the temperature of the inner bath is raised to 70 ° C., and stirring is continued for about 2 hours.

The glass transition point of the copolymer thus obtained is 221 ° K.
And the weight average molecular weight (from GPC measurement) was 570,000.

Next, the copolymer was coated on a release paper having been subjected to surface silicone treatment so that the thickness after drying was 35 μm, and the temperature was 130 ° C.
For 5 minutes.

Pressure-sensitive adhesive layer (B to D) Except for using the monomer mixture shown below, it was produced in the same manner as in the pressure-sensitive adhesive layer (A).

Pressure-sensitive adhesive layer (B) 2-ethylhexyl acrylate 90 parts Ethyl acrylate 5 parts Acrylic acid 5 parts Pressure-sensitive adhesive layer (C) Isononyl acrylate 60 parts Butyl acrylate 35 parts Acrylic acid 5 parts Pressure-sensitive adhesive layer (D) 90 parts of isononyl acrylate 5 parts of butyl acrylate 5 parts of acrylic acid The water vapor permeability, glass transition point, and weight average molecular weight of each of these were as shown in Table 2.

Examples 1 to 12 of the external material The external material of the present invention is subjected to a corona treatment on one surface of the porous plastic base material (I to VII), and to the pressure-sensitive adhesive layer with the release paper (A to D). I got

The moisture permeability, adhesive strength and holding power of this product were as shown in Table 3.

Note 3) The adhesive strength shown in Table 3 was measured by the following method.

The external material was cut to a width of 20 mm, and a 180 ° peeling adhesive force (g / 19 mm) was measured according to JIS Z-1528 using a bakelite plate as an adherend.

Note 4) The holding power shown in Table 3 was measured by the following method.

The external material was cut into a length of 20 mm and a width of 10 mm, and the cut piece was attached to a bakelite plate, and the load (500 g) was applied at a temperature of 40 ° C. to measure the time (minute) until the cut piece dropped.

(G) Effects of the Invention The external material of the present invention has the above-mentioned structure, and when adhered to the skin, has excellent followability to the movement of the skin, has no strange feeling such as tension, and has moisture permeability. It has excellent effects as a medical pressure-sensitive adhesive sheet, such as being less likely to cause stuffiness and irritation and less irritation.

Further, since the external material of the present invention is not made porous by perforating with a drilling machine, it also has a waterproof effect, and may be used by providing a pad such as gauze or absorbent cotton on the pressure-sensitive adhesive layer of the external material. In addition, since the pad hitting the wound does not get wet, it has an effect that the scratch is quickly broken.

Furthermore, unlike the conventional polyolefin porous membrane, the external use material of the present invention has limited physical properties and a manufacturing method so that it can follow the movement of the skin. It has the effect of no mechanical stimulus.

As a porous plastics base material, a sheet-like molded product composed of 10 to 80 parts by weight of an ethylene-propylene rubbery elastic composition and 100 to 300 parts by weight of a filler was formed with respect to 100 parts by weight of a polyolefin resin as a base material. The use of such a material has the effect of further improving the air permeability and the moisture permeability and obtaining an external material having extremely excellent followability to the skin.

Further, as the pressure-sensitive adhesive layer, a polymer of a carboxyl group-containing copolymerizable monomer, an acrylic acid or methacrylic acid alkyl ester monomer (having 1 to 14 carbon atoms), and a vinyl monomer copolymerizable therewith. An external material that is composed of a copolymer with a body, and that has an average molecular weight of 50,000 or more and a glass transition point of 250 ° K or less, has good air permeability and moisture permeability, and has no skin irritation. Is obtained.

Continuation of the front page (72) Inventor Satoru Gunji 1-2-1 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation (56) References JP-A-62-82967 (JP, A) 185415 (JP, U)

Claims (3)

(57) [Claims] 1. A porous plastics base material comprising a polyolefin resin has a tensile strength of 100 to 500 kg / cm ² and an elongation of 50%.
As described above, the 20% modulus is in the range of 25 to 100 kg / cm ² , and the moisture permeability when the pressure-sensitive adhesive layer is provided on one surface of the porous plastic substrate is 300 g / m ² · 24 hr or more. Features for external use. 2. A sheet-like molded product comprising a porous plastics base material comprising 10 to 80 parts by weight of an ethylene-propylene rubbery elastic composition and 100 to 300 parts by weight of a filler based on 100 parts by weight of a polyolefin resin. The external material according to claim 1, which is formed by stretching. 3. A polymer comprising a carboxyl group-containing copolymerizable monomer, an acrylic acid or methacrylic acid alkyl ester monomer (having a carbon number of 1 to 14), and a vinyl copolymerizable therewith. The copolymer has a weight average molecular weight of 50,000 or more and a glass transition point of 250 ° K.
The external use material according to claim 1 or 2, which has the following range.