JPH0794583B2 - High water content polymer gel - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel high water content polymer gel, more specifically, excellent water retention, water absorption, adhesiveness, shape retention, etc. The present invention relates to a highly water-containing polymer gel with significantly improved feeling.

2. Description of the Related Art Conventionally, skin patches are called poultices, ship agents, dressings, etc., for example, to cool parts such as bruise, sprains, etc., to protect blister, octopus, shoe rubs, external wounds, etc. It is widely used in a wide range of applications such as absorption of exudate, replenishment of water to dry skin, etc.

Thus, the above-mentioned skin patch conventionally known is generally based on a water-soluble polymer gel body,
Examples of the gel body include sodium polyacrylate, polyvinyl alcohol, polyvinylpyrrolidone, sodium carboxymethyl cellulose salt, isobutylene-maleic anhydride copolymer, gelatin, starch and the like, which are cured with a curing agent or the like in the presence of water. Those obtained by crosslinking by irradiation with radiation are well known.
Further, as the above-mentioned skin patch, there is also known one in which a drug is added to the gel body depending on the purpose. The publicly known techniques are described in more detail below, for example. That is, Japanese Patent Publication No. 61-41926
The publication discloses a gel composed of sodium polyacrylate, lactic acid and aluminum hydroxide, and other components such as methyl salicylate may be added to the gel as required. JP-A-60-99180 discloses an aqueous patch composition comprising polyacrylic acid, polyacrylic acid salt, cellulose derivative, polyhydric alcohol and polyvalent metal compound. Japanese Unexamined Patent Publication (Kokai) No. 62-111918 discloses a hydrous patch comprising a monovalent polyacrylic acid salt, a hydrophilic polymer having a carboxyl group, an aluminum salt and a polyhydric alcohol. Further, JP-A-60-60854 discloses a patch base comprising a polyhydric alcohol, sodium polyacrylate, sodium carboxymethyl cellulose, an aluminum compound and a polyacrylate.

Problems to be Solved by the Invention However, the above-mentioned conventional techniques have the following problems in implementing them.

That is, since the conventional gel body has a high concentration of at least 10% by weight of the solid component such as the polymer and the curing agent,
It has a low water content and cannot sufficiently exert a remarkable cooling effect on the skin. Alternatively, even if the water content is sufficiently high, sodium polyacrylate or the like is used alone as the gel-forming polymer, or the amount of non-sticking component such as kaolin, titanium oxide or alumina is large. , Poor and good sticking property to skin, not practical. Further, in the manufacturing stage, there is a drawback that it is difficult to obtain a uniform product with considerable difficulty in the process of dissolving and decomposing in water.

On the other hand, if it is attempted to reduce the amount of the non-adhesive component blended in order to avoid the above-mentioned problems, then the gel body loses its shape-retaining property, resulting in the problem that only a soft product that does not retain its outer shape can be produced.

Means for Solving the Problems In view of the above-mentioned present situation, the present inventors have conducted earnest studies for the purpose of eliminating all the defects found in the conventional gel body of this kind. As a result, when a specific component is used, even if the water content is 90% by weight or more, it is possible to produce a gel body having a sufficient shape retention property and a remarkable cooling effect, thus achieving the above object. As a result of finding out what can be done, the present invention has been completed here.

That is, the present invention relates to a high water content polymer gel characterized by containing sodium polyacrylate, polyacrylic acid, glycerin and aluminum chloride as main components and having a water content of 90 to 98% by weight.

The highly water-containing polymer gel of the present invention, which contains the above main component and has a water content of 90 to 98% by weight, exhibits a remarkable cooling effect particularly on the skin and has a good adhesiveness to the skin. And a gel having sufficient shape retention can be obtained. Therefore, the highly hydrous polymer gel of the present invention is used as a patch for bruising, spraining, blister, octopus, shoe rubbing, trauma, burns, insect bites, bed sores, purulent skin inflammation, sunburn etc. It can be cooled and is extremely effective in improving symptoms.

Further, the gel of the present invention has good adhesiveness to the skin and retains sufficient shape retention property, so that it easily fits on the skin, is hard to peel off, does not fall off, and has an excellent external impact absorption patch. can do.

Furthermore, since the gel of the present invention has a high water content, it can replenish water to moisturize dry skin, while exudate due to the water-absorbing ability of the polymer to inflamed skin such as pus that exudes. It also has the effect of absorbing

As the sodium polyacrylate that is the basic base of the gel of the present invention, any of various widely used ones can be used.

As the polyacrylic acid which is the basic base of the gel of the present invention together with the above-mentioned sodium polyacrylate, various polyacrylic acids generally referred to as carboxyvinyl polymers can be used, which particularly serve as a tackifier.

The blending ratio of the above two components is sodium polyacrylate 1
Usually, about 0.3 to 0.5 parts by weight of polyacrylic acid is preferable with respect to parts by weight in order to improve the adhesiveness of the gel to the skin. Further, the total amount of both components, in order to make the shape-retaining property of the gel preferable as a patch,
Generally, about 1 to 6% by weight is preferable.

In particular, the gel body of the present invention is based on the combined use of the above-mentioned sodium polyacrylate and polyacrylic acid, and has the advantage that the adhesiveness and re-adhesiveness become very excellent, and the compounding ratio of polyacrylic acid By setting the above range to the above range, there is an advantage that it becomes practical in terms of releasability.

As glycerin which is one of the main components of the gel of the present invention, a general commercial product can be used. This functions as a water retention agent or a dissolving agent or a dispersing agent when dissolving or dispersing sodium polyacrylate in water. The amount of glycerin added is not particularly limited, but in order to reduce the burden of mixing the components during production and to sufficiently maintain the water retention of the gel, it is usually about 0.25 per 1 part by weight of sodium polyacrylate. ~ 1.5
It is preferably in the range of about parts by weight. The glycerin may be used in combination with a polyhydric alcohol such as methanol, ethanol, propanol or ethylene glycol, propylene glycol, diethylene glycol, etc., within a range that does not impair the original action and the effect expected in the present invention.

In the present invention, as the aluminum chloride, both anhydrous and hydrated products can be used. It functions as a crosslinker for sodium polyacrylate and polyacrylic acid,
The combination has the effect of gelling the entire system. The amount of aluminum chloride added is not particularly limited,
Generally 0.02 for 1 part by weight of sodium polyacrylate
The amount may be in the range of about 5 to 0.5 parts by weight, and the gelled state can be improved by using in this range. The aluminum chloride is, for example, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, calcium chloride, magnesium chloride, aluminum sulfate, magnesium oxide, etc. within a range that does not impair the original action and the effect of the present invention. You may use together.

Various additives may be added to the gel of the present invention in addition to the above essential components. Examples of the additive include ethylenediaminetetraacetic acid disodium salt (EDTA), acetic acid,
Examples thereof include gelling rate regulators such as citric acid, boric acid, fumaric acid and sodium hydrogen carbonate. ED among them
TA is preferred. The EDTA functions as a so-called gelation rate retarding agent, and in the case where the gelling reaction is too fast in the manufacturing process and it is difficult to obtain a uniform gel, the workability is lowered,
By using this, the gelation reaction rate of the entire system can be delayed and the work efficiency can be made appropriate. The addition amount is up to about 10 parts by weight with respect to 1 part by weight of aluminum chloride,
It is preferably about 0.01 to 10 parts by weight.

The water content of the gel of the present invention can be set in the range of 90 to 98% by weight, preferably 92 to 96% by weight, regardless of whether or not the above-mentioned additive is added, and the water content in this range is set. By doing so, a desired effect can be imparted to the gel of the present invention. However, if this water content is less than 90% by weight, a remarkable cooling effect on the skin, that is, a cool and unique feeling cannot be obtained, and if it exceeds 98% by weight, a remarkable cooling effect is obtained, but the polymer concentration Is too low, resulting in poor releasability, shape retention, water retention, and shock absorption, and a gel that can withstand practical use cannot be obtained.

Incidentally, the gel of the present invention, various drugs depending on the purpose of use, such as hemostatics, bactericides, antibiotics, anti-inflammatory agents, the main components,
It is also possible to add the water and the additives so as to be in the above range.

The gel of the present invention can be produced by various methods. The following method can be illustrated as a preferable example. That is, first add 0.1 to 1 g of aluminum chloride, 0.01 to 1 g of EDTA if necessary, with water 5
A solution A is prepared by mixing and dissolving it in 0 to 70 g in advance, and 2 to 4 g of sodium polyacrylate and 1 to 3 g of glycerin are separately mixed and swollen to prepare a solution B, and further polyacrylic acid 0.
Liquid 6 is prepared by mixing 6 to 2 g with water 10 to 30 g and dissolving.
Then, the gel of the present invention can be prepared by mixing these three liquids. More preferably, the above-mentioned three liquids are mixed first with A liquid 50.
It can be carried out by adding ˜70 g to solution 4 to 6 g and allowing it to swell sufficiently, then adding this to solution C to 20 to 40 g and kneading for 10 to 20 minutes.

EFFECTS OF THE INVENTION The highly hydrous polymer gel of the present invention is used as a patch for bruising, spraining, blister, octopus, shoe rubbing, trauma, burns, insect bites, bed sores, purulent skin inflammation, sunburn, and dry skin protection. Applicable. Thereby, the affected area can be cooled to suppress fever and inflammation, water can be replenished to the skin, exudate can be absorbed, and the impact of external force can be absorbed, which is extremely effective in improving symptoms.

Moreover, since the highly hydrous polymer gel of the present invention has an appropriate tackiness, a patch having an excellent usability can be obtained.

Examples Hereinafter, in order to explain the present invention in more detail, examples of producing the highly hydrous polymer gel of the present invention will be given as examples, and examples of producing gels for comparative tests will be given as comparative examples.

Example 1 0.4 g of aluminum chloride, 0.1 g of EDTA and 62.7 g of water were mixed.
A solution was obtained by dissolving. 2.8g of sodium polyacrylate (Aronbis S: Nippon Pure Chemical) and 2.0g of glycerin are mixed.
It was swollen to obtain a liquid B. Further, 12 g of a 10% polyacrylic acid solution (Jurimer AC-10SH: Nippon Pure Chemical) and 20 g of water were mixed and dissolved to obtain a C solution. Solution A was added to solution B and allowed to swell sufficiently, and the solution obtained was added to solution C and kneaded for 10 minutes to obtain a highly hydrous polymer gel of the present invention.

Examples 2 to 5 and Comparative Examples 1 to 5 In the same manner as in Example 1, high water content polymer gels and comparative gels of the present invention having the formulations shown in Table 1 were obtained. The formulation of the gel obtained in Example 1 is also shown in Table 1.

Evaluation Test The gels obtained in Examples and Comparative Examples were applied to polyethylene films with a thickness of 3 mm and cut into a size of 10 × 10 cm to obtain evaluation test samples.

Regarding the evaluation method, the above sample was attached to the back of the hand and the following items were evaluated.

(1) Cooling sensation: Remarkable cooling sensation when applied to the skin, that is, coolness (2) Adhesiveness: Moderate adhesion to the skin (3) Releasability: Part of the gel when peeling the sample from the skin Whether it can be easily peeled off without remaining on the skin (4) Re-adhesion: Whether the sample once peeled can be re-adhered to the skin (5) Shape retention: Presence or absence of deformation when applied to the skin (6) Water retention: Whether or not water is released during storage, pressurization or application to the skin (7) Shock absorption: When applied to the skin, 20 cm from above
Presence or absence of impact relaxation when dropping weight of g is shown in Table 2 above.

It is clear from Table 2 that the high water content polymer gel of the present invention has a significantly excellent cooling sensation when it is applied to the skin and has an appropriate tackiness, is easy to peel off and can be applied again. Further, the gel of the present invention does not flow and has a good shape-retaining property, the water contained in the gel is not released, and it is also excellent in water retention.

In addition, Example 1 and Example 5 have the same formulation except for EDTA, and the same result was obtained in the evaluation test, but in Example 1, by adding EDTA as the gelation rate retarder,
In the step of mixing and kneading the three liquids of A liquid, B liquid and C liquid, a uniform gel body can be obtained even by a slow kneading operation,
In this respect, workability was better than that of Example 5 in which EDTA was not added.

On the other hand, the gels of Comparative Examples 1 and 2 had a water content of less than 90% by weight, and thus had a very poor cooling sensation effect. Further, the gel of Comparative Example 2 contained no polyacrylic acid, and thus had no stickiness and re-adhesiveness. Very bad in terms. The gel of Comparative Example 3 has a water content of 98.
%, The mechanical strength of the gel, that is, the releasability, shape-retaining property, shock absorbing property and water repellency is poor, and the gel of Comparative Example 4 has a weight ratio of sodium polyacrylate and polyacrylic acid of 1: 0.3. Therefore, the gel of Comparative Example 5 has a weight ratio of sodium polyacrylate and polyacrylic acid of more than 1: 0.5. Was too strong, and the releasability was extremely poor.

Next, a production example of a patch using the gel of the present invention will be shown as an application example.

Application Example 1 Using the gel of the present invention obtained in Example 1, a patch having the constitution schematically shown in Fig. 1 was prepared. That is, a patch having the structure schematically shown was prepared. That is, the gel (2) is attached to the center of the polypropylene non-woven fabric (4) by utilizing the adhesive property of the gel, and then the polyacrylate emulsion adhesive (3) is applied to the non-woven fabric around the gel to prepare an emulsion. After air-drying the water content, a polyethylene film (1) was attached to prevent evaporation of the water content in the gel. Further, for the same purpose, a polyethylene film was attached to the central part of the non-woven fabric on the opposite side of the gel via a polyacrylate emulsion pressure-sensitive adhesive to obtain a patch.

Application Example 2 Using the gel of the present invention obtained in Example 2, a patch having the constitution schematically shown in Fig. 2 was prepared. That is, the gel (2) is attached to a polypropylene nonwoven fabric (4) by utilizing the adhesiveness of the gel, and is attached to a polyvinyl chloride film (5) via a polyacrylate adhesive (3), and further the gel The polyethylene film (1) was attached to the entire side surface to obtain a patch.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of the patch prepared by using the gel of the present invention in Application Example 1, and FIG. 2 is a cross-sectional view of the patch prepared in Application Example 2 of the same. (1) …… Polyethylene film (2) …… Highly water-containing polymer gel of the present invention (3) …… Adhesive (4) …… Polypropylene nonwoven fabric (5) …… Polyvinyl chloride film

Claims (3)

[Claims] 1. A sodium polyacrylate as a main component,
A highly water-containing polymer gel containing polyacrylic acid, glycerin and aluminum chloride and having a water content of 90 to 98% by weight. 2. The highly hydrous polymer gel according to claim 1, wherein the weight ratio of sodium polyacrylate to polyacrylic acid is 1: 0.3 to 0.5. 3. The highly hydrous polymer gel according to claim 1 or 2, which is obtained by adding 0.01 to 10 parts by weight of ethylenediaminetetraacetic acid disodium salt as a gelling rate retarder to 1 part by weight of aluminum chloride.