JPS615012A - Spreading plaster - Google Patents

Abstract

PURPOSE:The titled plaster getting to fit cotton cloth, improved adhesivity to the skin and greasiness, comprising an ethylene-vinyl acetate copolymer resin having a vinyl acetate content and a melt index both in specific ranges as a base. CONSTITUTION:The titled plaster comprising an ethylene-vinyl acetate copolymer having 15-50wt% vinyl acetate content and 30-500(g/10min) melt index as a base. When the spreading plaster is mixed with a specific drug component, a hydrocarbon such as liquid paraffin, vaseline, squalane, etc. may be used as a solvent to dissolve or disperse the component. In the spreading plaster, when adhesivity to the skin is not sufficient by the influence of an added component, etc., a pressure-sensitive adhesive of polyisobutylene, terpene resin or olefinic resin as an active ingredient is added to the plaster, the adhesivity can be freely adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in patches, particularly plasters.

Plastering agents use polymers such as natural rubber or synthetic rubber, which have a relatively low water content, as a base material, but the manufacturing method of plastering agents using natural rubber or rubber materials such as styrene and isobutylene is described in the literature ( For example, edited by Masayasu Sugihara et al.
As is clear from "Pharmaceutical Engineering Hands, 30th Edition, page 228)," there are processes such as primary kneading and secondary kneading.

In the process of spreading onto flannel, nonwoven fabric, plastic film, etc. (backing), methods such as spreading using a solvent or heat-pressing are used. As described above, the method for producing plaster is very complicated and requires a great deal of time and effort.

Therefore, the present inventors conducted extensive research to find an excellent base material for plaster that does not have the above-mentioned drawbacks, etc., and as a result found that ethylene-vinyl acetate copolymer resin met the purpose and completed the present invention.

Ethylene vinyl acetate copolymer resin (hereinafter abbreviated as RVA)
To make plaster based on
After heating to around 0℃ to melt the base, 40 to 130℃
All you have to do is maintain the temperature at a moderate temperature, add various additives, and mix.

Not only is there no need for a kneading process, the base material is dissolved when spreading onto the backing, so there is no need for a solvent, and there is no need for pressure bonding, just apply it to a uniform thickness on top of the packing. .

That is, when producing a patch using ICVA, no complicated operations are required, and therefore, there is no risk of malfunction, and process control is not only easy.

It exhibits appropriate viscoelasticity so that there is no risk of leakage when spread on fabric, and also has excellent adhesion to the skin.

Note that EVA is a copolymer resin of ethylene and vinyl acetate, and is used as an adhesive for conventional packaging, bookbinding, and woodworking, and TC is a modifier for paraffin, wax, camphor, asphalt, etc., and an adhesive for adhesive tapes or sheets. Although scales are known to be used as adhesives, the present inventors discovered their use as a patch base for the first time.

When EVA is used as the base for the patch of the present invention, the vinyl acetate content (saponification method) is 15 to 50 wt% and the melt index (JIS: Ni-6760-1966) is 3.
A KVA of 0 to 5009710 minutes is preferred. The higher the vinyl acetate content, the better the adhesion to the skin, the lower the melting point, and the easier production, but the stronger the acetic acid odor.

Also, as the vinyl acetate content decreases, the crystallinity of KVA increases, making it stiff and difficult to stick to the skin. Therefore, ICVA with a degree of saponification of about 15 to 5 oyt% is preferable. Furthermore, when the melt index increases, the cohesive force decreases, making it easy to flow and making it difficult to spread, and at the same time, it becomes sticky and has a poor feel when used.

On the other hand, as the melt index decreases, the cohesive force increases and the adhesion to the skin deteriorates. Therefore 30-500
A melt index of the order of (g/l 0 min) is preferred.

Usually, when a patch contains a specific medicinal ingredient, alcohols such as glycerin and propylene glycol or liquid paraffin are used as solvents for dissolving or dispersing the ingredient.
Hydrocarbons such as vaseline and squalane, fats and oils such as olive oil and soybean oil, and fatty acids such as lauric acid and myristic acid can be considered, but hydrocarbons are preferred in the present invention. Alcohols, fats and oils, or fatty acids are base E
It is not compatible with VA and cannot be uniformly dissolved or dispersed.
It is separated from KVA and cannot be used.

When the patch of the present invention does not have sufficient adhesion to the skin due to the influence of added components, etc.

Adhesive properties such as polybutene, polyisobutylene, terpene resin, or olefin resin can be added to ETA to freely adjust the adhesion.

The conformability of the patch to the fabric at the time of manufacture or the conformability to the skin (feeling of fit or stiffness) when using the patch is determined by EVA.
Dioctyl phthalate.

It can be freely prepared by adding plasticizers such as chlorinated halafine and nonylphenyl ethers.

Examples are shown below, but the present invention is not limited to these examples. In the examples, d-camphor is used as an anti-inflammatory analgesic. - Menthol, salicylic medyl, and chili oil were mixed in a ratio of 21:24:24:81 (weight ratio) and added as the main component oil, but the anti-inflammatory and analgesic agents are not limited to these, but include indomethacin, ketopro7ene, It is also possible to add drugs such as diclofenac sodium or steroid hormones, nitriglycerin, and scopolamine. Also, 7 runnel, non-woven fabric as backing.

Plastic films such as vinyl chloride/l/film and polyethylene film can be used.

The coating amount can also be made from a thickness of 0.01w or more.

Example 1 Vinyl acetate content 45 wt%, melt index 30
(9/10 minutes) EVA (product name: Evafre, Cus 45)
X) Heat 98.5 parts to 130°C to melt it, cool it while stirring, and after confirming that the temperature is below 90°C, add 1.5 parts of the main component oil (above) and mix it with a cotton cloth. The patch was coated on top to a thickness of about 1 inch and cooled to obtain a patch.

Example 2 Same as Example 1 - 90 parts of EVA was heated to 130°C to melt it, and then cooled to 90-100°C.

8.5 parts of light liquid paraffin (Japanese Pharmacopoeia compliant product) previously heated to 90°C was added, stirred well to mix uniformly, and then cooled while stirring.

After confirming that the temperature was below 90°C, 1.5 parts of the main component was added, and the mixture was coated on a cotton cloth to a thickness of about III@ while stirring, and cooled to obtain a patch.

Example 8 Vinyl acetate content 25 wt%, melt index x+o
o (ri 710 minutes) xv * (z buff flex 810)
After heating 60 parts to 130°C to melt, add 88.5 parts of polyisobutylene and mix well until uniform. The mixture was cooled while stirring, and after confirming that the temperature was below 90°C, 1.5 parts of the main component was added, and the mixture was coated on a cotton cloth to a thickness of about 1 m while stirring, and cooled.

A patch was obtained.

Example 4 Same as Example 8 - After heating and melting 60 parts of EVA to 1aO"C, add 37 parts of polyisobutylene and 1.5 parts of polyoxyethylene nonylphenyl ether and stir well to mix until uniform. .Cool while stirring9.
After confirming that the temperature was below 0°C, 1.5 parts of the main component was added, and the mixture was coated on a cotton cloth to a thickness of about 1 m while stirring, and cooled to obtain a patch.

Example 5 Same as Example 1 - 59 parts of EVA was heated to 130°C and melted, and then 10 parts of polybutene (average molecular weight 2850),
Add 10 parts of light liquid paraffin (product conforming to the Japanese Pharmacopoeia), 15 parts of terpene resin, and 4.5 parts of hyphoryoxyethylene nonylphenyl ether and stir to make the mixture uniform. Cool while stirring and confirm that the temperature is below 90°C.

1.5 parts of the main component was added, and the mixture was coated on a cotton cloth to a thickness of about 1 piece while stirring, and cooled to obtain a patch.

All of the patches obtained above blended well with cotton cloth and had excellent adhesion to the skin and stickiness.

Claims (2)

[Claims] (1) A patch characterized by using an ethylene vinyl acetate copolymer resin having a vinyl acetate content of 15 to 50 wt% and a melt index of 30 to 500 g/10 minutes. (2) 1 part hydrocarbon such as liquid paraffin or squalane
The adhesive patch according to claim 1, in which more than one component is added.