JPH0899871A - Application agent - Google Patents

Abstract

PURPOSE: To obtain an application agent, having low skin irritancy, usable for a person, having hypersensitive skin and readily causing the contact dermatitis and suitable as an adhesive tape, etc., by forming a tacky agent layer comprising prescribed amounts of an alkyl (meth)acrylate (co)polymer, triacetin, etc., on a support. CONSTITUTION: This application agent is obtained by forming a tacky agent layer comprising preferably 40-75wt.% alkyl (meth)acrylate (co)polymer, 8-40wt.% triacetin or nitroanisole, preferably 8-18wt.% silicic acid anhydride and preferably <=25wt.% alkyl ester of a fatty acid such as octyl laurate on a support.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a patch, and more particularly to a patch used for plasters, tapings and the like.

[0002]

2. Description of the Related Art External preparations for skin surface application such as patches and tapes using a plaster or an adhesive that has been developed as a percutaneous absorption agent for administering a plaster or a drug into the living body through the skin surface. Are often applied to the same place for a long time or repeatedly, and itching of the skin surface, skin irritation, exfoliation of the keratin, etc. are problems.

In order to solve this skin irritation, a preparation which does not cause skin irritation when it is peeled from the skin is disclosed by providing an adhesive layer having an adhesive force that does not cause exfoliation of the keratin (Japanese Patent Laid-Open Publication No. HEI 5 (1993) -1993). 65224). However, it has been difficult for humans with sensitive skin to suppress skin irritation such as reddening of the skin upon peeling, itching during application, and development of erythema.

Also disclosed is a nitroglycerin patch having low skin irritation, in which an adhesive layer containing a (meth) acrylic acid alkyl ester copolymer, nitroglycerin, and silicic acid anhydride is provided on a support. (Japanese Patent Laid-Open No. 3-291217). However, when nitroglycerin was removed from this adhesive layer, the effect of low skin irritation was not exhibited, and it was difficult to apply it to a plaster or taping.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and an object of the present invention is to provide a patch which can be used even by people with sensitive skin and rashes. It is in.

[0006]

[Means for Solving the Problems]

The patch of the present invention comprises a (meta) on a support.
A pressure-sensitive adhesive layer comprising an acrylic acid alkyl ester (co) polymer, triacetin or nitroanisole, silicic acid anhydride and a fatty acid alkyl ester is provided.

The above-mentioned support is preferably one having a gas barrier property which is generally used as a support for patches, and examples thereof include resin films such as polyester, polyamide, polyvinylidene chloride, polyvinyl chloride, polyethylene and polypropylene. Examples include aluminum sheets, which may be used as a single-layer sheet or as a laminate of two or more kinds. In particular, a laminate of polyethylene or polyester and an ethylene-vinyl acetate copolymer, or a laminate of polyvinyl chloride-polyethylene is preferable.

As the (meth) acrylic acid alkyl ester constituting the above-mentioned (meth) acrylic acid alkyl ester (co) polymer, when the carbon number of the alkyl group decreases,
The cohesive force of the obtained pressure-sensitive adhesive layer is improved, but the cohesive force is decreased, and when the cohesive force is increased, the cohesive force is decreased but the cohesive force is decreased. Therefore, one having 6 to 18 carbon atoms is preferable, and for example, 2-ethylhexyl (meta ) Acrylate, hexyl (meth)
Examples thereof include acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate and the like.

2-Ethylhexyl (meth) acrylate is particularly preferred as the (meth) acrylic acid alkyl ester constituting the above copolymer. In the above copolymer,
When the amount of 2-ethylhexyl (meth) acrylate is small, the cohesive force of the pressure-sensitive adhesive layer is reduced and the adhesive layer is excessively softened,
If it increases, the adhesive layer will become hard and the adhesive strength will decrease, so
It is preferably 40 to 90% by weight, more preferably 60 to 8
0% by weight.

The amount of the copolymer in the pressure-sensitive adhesive layer is
If the amount decreases, adhesive residue will occur and the usability will deteriorate,
Since the tackiness decreases as the amount increases, it is preferably 35 to 85% by weight, more preferably 40 to 75% by weight.

A radical-polymerizable polyfunctional monomer may be added to the above-mentioned copolymer, if necessary. As such a polyfunctional monomer, one having two or more radical-polymerizable functional groups such as vinyl group and allyl group in one molecule is preferable, and examples thereof include divinylbenzene, methylenebisacrylamide, and ethyleneglycoldiene. (Meth) acrylate, propylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, hexylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, trimethylolpropane tri (Meth) acrylate etc. are mentioned.

When the amount of the polyfunctional monomer added is too large, gelation occurs during the polymerization and a uniform polymer solution cannot be obtained. Therefore, 0.1% by weight or less of the total amount of the monomers constituting the copolymer is used. Is preferred, and more preferably 0.01
Is 0.1% by weight.

As the above-mentioned silicic acid anhydride, a hydrophilic one having a hydroxyl group on its surface is generally used. However, the hydrophobic hydroxyl group of which the hydroxyl group on the surface is treated with dimethyldichlorosilane and which is covered with a dimethylsilanol group is hydrophobic. Silica anhydride may be used.

In the present invention, as the above-mentioned silicic acid anhydride,
When only hydrophilic silicic acid anhydride is used, if the amount used in the pressure-sensitive adhesive layer exceeds 5% by weight, thixotropy becomes too large, and coating with a roll coater or a blade becomes difficult. Moreover, since the obtained pressure-sensitive adhesive layer easily absorbs moisture, it becomes easy to peel off when used as a patch. Therefore,
In the present invention, a mixture of hydrophilic silicic acid anhydride and hydrophobic silicic acid anhydride is preferably used as the silicic acid anhydride.

In the mixture of the above-mentioned hydrophilic silicic acid anhydride and hydrophobic silicic acid anhydride, when the amount of the hydrophobic silicic acid anhydride is small, the coating property and the sticking property are not sufficiently improved, and when it is large, the tackiness is increased. Since the effect of improving the cohesive force of the agent layer decreases, 2
0 to 80% by weight is preferable.

The particle size of the silicic acid anhydride is 0.01 to several 1
0 μm is preferable.

When the amount of the above-mentioned silicic acid anhydride is reduced, the effect of improving the cohesive force of the obtained pressure-sensitive adhesive layer is small, and when it is increased, the pressure-sensitive adhesive layer is reduced in adhesive force.
20 wt% is preferable, more preferably 8-18 wt%
Is.

The above-mentioned triacetin is a liquid component having a structure similar to nitroglycerin and is a substance whose safety has been confirmed (J. of Pharmacology and Experime).
ntalTherapeutics, 82,377,1977, Federation Proceedi
ngs, Federation of American Societies for Experime
ntal Biology, 22, 368, 1963).

When the amount of triacetin used is small, the effect of reducing skin irritation is not sufficient, and when it is large, the pressure-sensitive adhesive layer causes stringing when the patch is peeled off, and the feeling of use deteriorates. Limited to 8-40% by weight,
It is preferably 10 to 30% by weight.

Examples of the nitroanisole include o-nitroanisole, m-nitroanisole and p-nitroanisole.

When the amount of nitroanisole used is small, the effect of reducing skin irritation is not sufficient, and when it is large, the adhesive layer causes stringing when peeling the patch,
Since the adhesive strength of the pressure-sensitive adhesive layer decreases and the usability deteriorates, it is limited to 8 to 40% by weight in the pressure-sensitive adhesive layer, preferably 10 to 40% by weight.
It is 30% by weight.

The fatty acid alkyl ester is preferably an ester of a fatty acid having 22 or less carbon atoms and a monohydric or dihydric alcohol having 22 or less carbon atoms, and examples thereof include neutral fatty acid ester, octyl lauryl acid ester and isopropyl myristate. , Octyldodecyl myristate, butyl stearate and the like, and these may be used alone or in combination of two or more kinds.

By adding the above-mentioned fatty acid alkyl ester, a pressure-sensitive adhesive layer exhibiting excellent tackiness with little irritation to the skin can be obtained. If the amount of the above fatty acid alkyl ester used is large, it becomes difficult to be compatible with each other in the pressure-sensitive adhesive layer, so that it is preferably 25 wt% or less.

The (meth) acrylic acid alkyl ester (co) polymer is usually prepared by blending the above-mentioned monomers in the presence of a polymerization initiator and carrying out solution polymerization. When carrying out solution polymerization, ethyl acetate or other polymerization solvent is added to a predetermined amount of various monomers, and in a reactor equipped with a stirrer and a cooling reflux device, a polymerization initiator such as an azobis-based or peroxide-based polymerization initiator is added. 70 to 90 in the presence of a nitrogen atmosphere
The reaction may be performed at 5 ° C for 5 to 40 hours. Further, the monomer may be charged all at once or dividedly.

As the azobis type polymerization initiator, 2,
2-azobis-iso-butyronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-
Examples thereof include azobis (2,4-dimethylvalerinitrile), and examples of the peroxide-based polymerization initiator include lauroyl peroxide, benzoyl peroxide, di (tert-butyl) peroxide, and the like.

In the patch of the present invention, a pressure-sensitive adhesive composition containing the above-mentioned (meth) acrylic acid alkyl ester (co) polymer, triacetin or nitroanisole, silicic acid anhydride and fatty acid alkyl ester is provided on a support. It is obtained by coating and drying to form a pressure-sensitive adhesive layer. As the method for forming the pressure-sensitive adhesive layer on the support, a solvent coating method, a hot melt coating method, an electron beam curing emulsion coating method or the like, which is a conventionally known method for producing a pressure-sensitive adhesive tape, can be used. The coating method is preferred.

Further, the pressure-sensitive adhesive composition may be applied onto release paper and dried to once form a pressure-sensitive adhesive layer, and then transferred and adhered onto a support. In this case, the release paper may be used to protect the adhesive layer of the patch until use.

[0029]

Next, embodiments of the present invention will be described. Synthesis of adhesive agent Dodecyl methacrylate 2,286 g, 2-ethylhexyl methacrylate 14,256 g, 2-ethylhexyl acrylate 1,656 g, hexanediol dimethacrylate 2.3 g, and ethyl acetate 8,500 g were put in a 40 liter polymerization vessel and heated to 80 ° C. The temperature was raised. Then, a solution prepared by dissolving 16 g of lauroyl peroxide in 1,500 g of cyclohexane was added to the polymerization vessel over 6 hours,
By polymerizing, weight average molecular weight 1.05 × 1
0 ^6, to give a solid content 58 wt% of (meth) acrylic acid alkyl ester copolymer solution.

Example 1 The above-mentioned (meth) acrylic acid alkyl ester copolymer solution had a solid content of 70% by weight,
8% by weight of triacetin (manufactured by Wako Pure Chemical Industries, Ltd.), hydrophobic silicic acid anhydride (“Aerosil R972” manufactured by Nippon Aerosil Co., Ltd.) 7
% By weight, 7% by weight of hydrophilic silicic anhydride (“Aerosil A200” manufactured by Nippon Aerosil Co., Ltd.) and 8% by weight of fatty acid alkyl ester (isopropyl alcohol myristate manufactured by NOF CORPORATION), and a solid content concentration of 30% by weight. Ethyl acetate was added to the mixture so as to adjust the mixture, and the mixture was uniformly mixed with a dissolver to prepare a pressure-sensitive adhesive composition. This pressure-sensitive adhesive composition was coated on polyester release paper so that the thickness after drying was 100 μm, and dried at 60 ° C. for 30 minutes to form a pressure-sensitive adhesive layer. Next, this adhesive layer was brought into close contact with the polyester side of a polyester / EVA laminated film (thickness of 32 μm) to prepare a patch.

Example 2 A patch was prepared in the same manner as in Example 1 except that the solid content of the copolymer solution was changed to 63% by weight and the triacetin content was changed to 15% by weight.

(Example 3) A patch was prepared in the same manner as in Example 1 except that the solid content of the copolymer solution was changed to 53% by weight and triacetin was changed to 25% by weight.

Example 4 A patch was prepared in the same manner as in Example 1 except that the solid content of the copolymer solution was changed to 43% by weight and the triacetin content was changed to 35% by weight.

Comparative Example 1 A patch was prepared in the same manner as in Example 1 except that the solid content of the copolymer solution was changed to 73% by weight and the triacetin content was changed to 5% by weight.

Comparative Example 2 A patch was prepared in the same manner as in Example 1 except that the solid content of the copolymer solution was changed to 35% by weight and the triacetin was changed to 43% by weight.

Comparative Example 3 52.7% by weight of the above copolymer solution as a solid content and 10% by weight of a 10% by weight ethyl nitroglycerin solution (manufactured by NOF Corporation) as 25.3% by weight of nitroglycerin and a hydrophobic anhydrous solution. 7% by weight of silicic acid (“Aerosil R972” manufactured by Nippon Aerosil Co., Ltd.), 7% by weight of hydrophilic silicic acid anhydride (“Aerosil A200” manufactured by Nippon Aerosil Co., Ltd.) and 8% by weight of fatty acid alkyl ester (isopropyl myristate manufactured by NOF CORPORATION) %, And adjusted by adding ethyl acetate so that the solid content concentration becomes 30% by weight, and then uniformly mixed by a dissolver to prepare an adhesive solution. Using this adhesive solution, a patch was prepared in the same manner as in Example 1.

Comparative Example 4 A patch was prepared in the same manner as in Comparative Example 1 except that triacetin was not used at all and 78% by weight of the above copolymer solution was used as the solid content.

Comparative Example 5 A patch was prepared in the same manner as in Example 3 except that 25% by weight of glycerin (manufactured by Wako Pure Chemical Industries, Ltd.) was used instead of 25% by weight of triacetin.

The following performance evaluations were performed on the patches obtained in the above Examples and Comparative Examples, and the results are shown in Table 1. (1) Guinea pig skin irritation test Hair was cut from the ventral side of a Hartley 5-week-old guinea pig, and the patch was occluded for 48 hours and then peeled off. Thirty minutes after peeling, the skin irritation was evaluated using the Draize criterion, and the average value was determined.

(2) Human skin irritation test: 20 normal males (test subjects) had a diameter of 2c inside the upper arm.
A patch of 4 m in a circle (area 3.14 cm ² )
It adhered for 8 hours and was peeled off. After peeling, the skin irritation was evaluated according to the judgment method of the Japanese patch test research group, the sum of the evaluation values was divided by the number of test subjects, and 100 was calculated to calculate the skin irritation index. A skin irritation index of less than 30 was evaluated as a safe product.

[0041]

[Table 1]

Example 5 70% by weight of the above copolymer solution as solid content, 8% by weight of o-nitroanisole (manufactured by Wako Pure Chemical Industries, Ltd.), hydrophobic silicic acid anhydride ("Aerosil R972" manufactured by Nippon Aerosil Co., Ltd.) ) 7% by weight, hydrophilic silicic acid anhydride (“Aerosil A200” manufactured by Nippon Aerosil Co., Ltd.) 7% by weight, and fatty acid alkyl ester (Nippon Yushi Co., Ltd .: isopropyl myristate) 8% by weight, solid content concentration 30 Ethyl acetate was added to adjust the content to be wt%, and the mixture was uniformly mixed with a dissolver to prepare an adhesive solution. Using this adhesive solution, a patch was prepared in the same manner as in Example 1.

Example 6 A patch was prepared in the same manner as in Example 1, except that the solid content of the copolymer solution was changed to 63% by weight and o-nitroanisole was 15% by weight.

Example 7 A patch was prepared in the same manner as in Example 1 except that the solid content of the copolymer solution was changed to 53% by weight and o-nitroanisole was 25% by weight.

Example 8 A patch was prepared in the same manner as in Example 1 except that the solid content of the copolymer solution was changed to 43% by weight and o-nitroanisole was changed to 35% by weight.

Comparative Example 6 A patch was prepared in the same manner as in Example 1 except that the solid content of the copolymer solution was changed to 73% by weight and o-nitroanisole was 5% by weight.

Comparative Example 7 A patch was prepared in the same manner as in Example 1 except that the solid content of the copolymer solution was changed to 35% by weight and o-nitroanisole was 43% by weight.

The patches obtained in Examples 5 to 8 and Comparative Examples 6 and 7 were subjected to the same guinea pig skin irritation test as in Example 1, and the results are shown in Table 2.

[0049]

[Table 2]

[0050]

The composition of the patch of the present invention is as described above and has low skin irritation, so that it can be suitably used as a plaster or a taping agent for people who are easily rashed on the skin.

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Claims (1)

[Claims] 1. A pressure-sensitive adhesive layer comprising a (meth) acrylic acid alkyl ester (co) polymer, triacetin or nitroanisole, silicic acid anhydride and a fatty acid alkyl ester is provided on a support, and triacetin or nitroanisole is contained. An adhesive patch characterized in that the amount is 8 to 40% by weight in the adhesive layer.