JP2000119128A - Cosmetic gel sheet and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cosmetic water-containing gel sheet as a thin membrane state, excellent in stick feeling in a good efficiency. SOLUTION: This cosmetic gel sheet is obtained by coating a water- containing gel layer consisting of a polyacrylic acid and its salt, water, glycerol, etc., by using a coating machine, on a gel-impregnating layer of a supporting body consisting of a non-gel-impregnating layer in which the water-containing gel can not penetrate, e.g. a polyethylene film/a pulp (a paper), a polyester film/a polyester non-woven fabric, etc., and a gel-impregnating layer in which the water-containing gel can penetrate to a part or whole of its inside. Then the sheet is instantly wound up in a roll state without drying beforehand, sealing with aluminum sheet, etc., and maturing at approximately 50 deg.C for approximately 3 days to perform a cross-linking.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cosmetic gel sheet and a method for producing the same. More specifically, the present invention relates to a cosmetic gel sheet obtained by coating a hydrogel into a thin film and a method for producing the same.

[0002]

2. Description of the Related Art As a gel sheet product used in the cosmetic field, a pack agent and the like are conventionally known. In recent years, diversification of gel sheet products has been attempted, focusing on the moisturizing effect of the skin, the feeling of cooling at the time of application, and the like. In particular, there is an increasing demand for thinner gel sheets from the viewpoint of improving the feeling of sticking to the skin surface and reducing costs during transportation.

A gel sheet product generally has a structure in which a water-containing gel layer containing a large amount of water is laminated on a support such as a polyester film, a polyethylene film or a nonwoven fabric. For the water-containing gel layer, generally, a carboxyl group-containing polymer such as polyacrylic acid, whose safety has been widely confirmed, is used, and the carboxyl group-containing polymer is converted to a polyvalent metal salt (for example, aluminum hydroxide or the like). Crosslinked ones are used.

[0004] Such a gel sheet is produced, for example, as follows. That is, various polymers having a carboxyl group are dissolved or suspended in a hydrophilic solvent such as an aqueous solution of water or alcohol, and this liquid material is applied on a separator film in a film form by casting or the like. Thereafter, the polyvalent metal salt is gelled, for example, by spraying the coated liquid material to form a hydrogel layer. Alternatively, a polyvalent metal salt is dissolved in the liquid material of the polymer, and a film is formed on a separator film using a coating machine. The gel film thus formed is directly or dried to evaporate a certain amount of water, and then transferred onto the above-mentioned support and wound into a roll. Finally, in order to complete the crosslinking, the gel sheet was heated at about 50 ° C. and aged for a long time, usually about 3 days, to obtain a gel sheet.

However, in the above method, since the crosslinking time by the polyvalent metal salt is long, if the film is left in a roll form, pressure is applied to the inside of the roll, and the gel is impregnated into the support and the thickness varies. There was a problem.
In particular, when an attempt is made to form a hydrogel layer in the form of a thin film, the thickness of the hydrogel layer varies greatly.

In the worst case, when a nonwoven fabric is used to improve the feeling of use during use, there is a problem in that the hydrogel layer penetrates to the back surface of the support, causing so-called strike-through.
In particular, when the thickness of the support was reduced in order to reduce the thickness of the gel sheet, manufacturing problems such as increased strikethrough and a large decrease in yield were likely to occur.

[0007] In order to solve these problems, various measures such as adjusting the crosslinking rate and selecting a support have been attempted. However, if an attempt is made to increase the crosslinking speed in order to shorten the crosslinking time, gelation occurs in the process of forming a film, the viscosity increases, and the pot life is shortened.
As a result, the film cannot be formed into a thin film, and when a conventionally used coating machine is used, the thickness becomes approximately 2 mm or more, and the thin hydrogel layer can be efficiently formed. I couldn't get it.

On the other hand, in order to shorten the crosslinking time, it is conceivable to use a support having good air permeability, for example, a nonwoven fabric or a woven fabric. The basis weight must be increased. As a result, there is a problem that the back surface of the support is caught on a nail or the like after being attached to the skin and easily peeled off. In addition, the sticking feeling is also given a rough feeling, and the usability is rather poor.

When the support is formed into a film in order to prevent strike-through, if the support is made of a hydrophobic material, the gel has a low anchoring property with the hydrogel. It is easy to remain. For this reason, it is necessary to perform a primer treatment on the support, which leads to an increase in the cost of the gel sheet. On the other hand, hydrophilic ones do not have such a drawback, but the problem of adhesive residue still tends to occur, for example, the strength of the support itself is reduced and it cannot be used.

Further, it is conceivable to heat and ripen the formed gel film without winding it into a roll. However, according to this method, it is necessary to secure a large working place at the time of heating and ripening. Efficiency was greatly reduced, making mass production difficult.

On the other hand, a method in which a solution of a polyvalent metal salt is sprayed after a solution of a polymer or the like is applied in a thin film form can form a thin hydrogel layer. However, it became complicated and the work efficiency could not be improved as expected.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to efficiently obtain a thin-film cosmetic gel sheet excellent in sticking feeling and the like.

As a result of intensive efforts, the present inventors have found that a thin-film gel sheet can be efficiently produced by using a support having a specific structure, and have completed the present invention.

[0014]

The cosmetic gel sheet according to the present invention is a cosmetic gel sheet comprising a sheet-like support and a hydrogel layer laminated thereon, wherein the support comprises a gel non-impregnated layer and a gel impregnated layer. Wherein the hydrogel layer is laminated on the gel-impregnated layer.

In the method for producing a cosmetic gel sheet of the present invention, a water-containing gel layer is formed into a thin film using a coating machine after mixing and stirring a polyvalent metal salt with a solution or suspension of a carboxyvinyl polymer. It is characterized by comprising a step of forming a film and a step of winding the film into a roll after forming the film, and applying heat in the wound state to ripen the film.

That is, in the present invention, a gel non-impregnated layer is provided on the outer surface of a gel impregnated layer in which a hydrogel layer is laminated, and the hydrogel layer is formed into a thin film, and then immediately wound into a roll. The purpose is to complete the crosslinking by heating.

Here, the gel-impregnated layer means a layer into which a hydrogel made of polyacrylic acid (salt) can partially or entirely enter, for example, pulp (paper), rayon, cotton and the like. A hydrophilic woven fabric or nonwoven fabric made of, a hydrophobic woven fabric or nonwoven fabric made of polypropylene or polyester, or a hydrophilic film made of polyvinyl alcohol or pullulan.

By forming the hydrogel layer on the gel-impregnated layer, the hydrogel penetrates a part or the whole of the gel-impregnated layer, and the anchoring property with the laminated hydrogel layer is improved. As a result, by forming the hydrogel layer into a thin film without increasing the crosslinking speed of the hydrogel itself, the hydrogel layer can be wound into a roll immediately after forming the hydrogel layer on the support.

On the other hand, the gel non-impregnated layer means a layer into which a water-containing gel cannot penetrate, such as an olefin-based film such as polyethylene and polypropylene, a soft vinyl chloride film, a polyester film, a nylon film, a polyurethane film and the like. Examples include various hydrophobic films and hydrophobic foam films made of various rubbers such as polyethylene, urethane, and SBR (styrene block copolymer). In particular, by using a polyurethane film, more specifically, a film made of polyether polyamide, polyether polyurethane, polyester polyurethane, polyether polyester, or ethylene / vinyl acetate copolymer, stretchability is improved. For this reason, it is convenient to stick to an elastic part such as a bent part such as an elbow or a knee. When an ethylene / vinyl acetate copolymer film is used, the content of vinyl acetate is preferably 20% or more.

The non-gel-impregnated layer constitutes the outer layer of the support, and is for preventing strike-through of the hydrogel layer formed on the gel-impregnated layer. As a result, even if the support on which the hydrogel layer is formed is wound into a roll and stored, the hydrogel layer does not strike through, and the thickness of the hydrogel layer formed on the gel-impregnated layer is kept constant. can do. For this reason, even when the hydrogel layer is formed into a thin film, the variation in thickness can be extremely reduced.

As the support that fulfills such a function, any combination of the above-mentioned gel non-impregnated layer and gel-impregnated layer can be used, and more specifically, polyethylene film / pulp (paper) , Polyester film /
A laminate such as a polyester nonwoven fabric, a polypropylene film / polyvinyl alcohol film, or an SBR foam film / polyester nonwoven fabric is suitably used.

In the above support, the gel-impregnated layer is
In the case of a nonwoven fabric, one having a basis weight of 10 to 60 g / m ² is used, and in the case of a film, one having a thickness of 5 to 100 μm is suitably used. Further, as the gel non-impregnated layer, a layer having a thickness of 1 to 100 μm is preferably used for a normal film, and a layer having a thickness of 0.3 to 1 mm is preferably used for a foam film. When the thickness is below this range, the above functions cannot be sufficiently exhibited, and when the thickness exceeds this range, the sense of thickness tends to be too large. Further, the thickness of the support is preferably 1 mm or less as a whole, preferably 500 μm or less, from the viewpoint of thinning. When the thickness is more than this, the gel sheet has a large thickness feeling and the gel sheet tends to be peeled off after application.

The support can be obtained by laminating the gel-impregnated layer and the gel-non-impregnated layer, but the method is not particularly limited, and examples thereof include dry lamination and various extrusion lamination methods. .

In addition, since the gel sheet of the present invention is used for cosmetic purposes, it may be desirable to give a cooling sensation when applied to the skin surface. In this case, it is desirable to promote evaporation of moisture from the back surface of the attached gel sheet in order to maintain a cooling sensation. By the way, in the above-mentioned support, since a film is used as a gel non-water-containing layer, evaporation of water from the gel non-water-containing layer is prevented. For this reason, it is not possible to give sustainability to the cooling sensation. Therefore, it is preferable to provide a large number of perforations in the film of the gel non-water-containing layer so that the hydrogel layer does not strike through. Although the size of the perforation is not limited,
Perforations of about 0 to 1000 μm, preferably about 200 to 500 μm, 1 to 100 / cm ² , preferably 5 to 50
It is preferable to provide them at a ratio of about pieces / cm ² .

The hydrogel layer is not particularly limited as long as it is used by spreading it in a sheet shape.
Polyacrylic acid or a salt thereof, polyvinyl alcohol, polyvinyl pyrrolidone, or other various water-soluble polymers which are crosslinked with polyvalent metal salts are used. In particular, in order to form a hydrogel layer in the form of a thin film, it is preferable to use one containing a carboxyvinyl polymer and crosslinked with a polyvalent metal salt.

Here, the carboxyvinyl polymer in the present invention is used in a broad sense and means a polymerized carboxyvinyl group such as polyacrylic acid or polyacrylate, and a part or all of the carboxyvinyl group is polymerized. It is a concept that includes those that have been neutralized and also those that have been partially crosslinked. Further, it is a copolymer mainly comprising acrylic acid and a small amount of allyl sucrose, which is commercially available under the trade names of Carbopol, Hibiswako, Junron, etc. This is a concept that also includes vinyl polymers.

As the carboxyvinyl polymer,
For example, polyacrylic acid and / or a salt thereof can be mentioned. As such polyacrylic acid and / or polyacrylate, those having a weight average molecular weight of 20,000 to 10,000,000, preferably 1,000,000 to 7,000,000 It is desirable to use. In addition, it is desirable to adjust the concentration to be about 2 to 30% by weight, preferably about 3 to 10% by weight in the water-containing gel layer. An optimum three-dimensional skeleton can be obtained by adjusting the concentration within the above range using a weight average molecular weight in the above range.

Further, in the present invention, it is preferable to blend a polyhydric alcohol. Examples of polyhydric alcohols contained in the hydrogel layer include glycerin and sorbitol, glycols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, and polypropylene glycol, 1,3-propanediol, Diols such as 4-butanediol can be used, and one or more kinds can be used in combination. Among these, it is preferable to use glycerin from the viewpoint of the moisturizing power and the precedent of use.

These polyhydric alcohols not only act as plasticizers for carboxyvinyl polymers such as polyacrylic acid and polyacrylate, but also retain moisture and exhibit a moisturizing effect. Its content is 5 to 90% by weight, preferably 10 to 80% by weight in the hydrogel layer. The content of polyhydric alcohols is usually 10 to
Although it is 50% by weight, it is not particularly limited.

The water contained in the hydrogel layer is an important component for moistening and hydrating the skin at the site of application, and is adjusted to at least 10% by weight or more, preferably 30 to 70% by weight. It is desirable. If the water content is less than 10% by weight, the hydration effect of the skin may not be sufficient.

Examples of the external cross-linking agent to be used for cross-linking the polyacrylic acid and / or polyacrylate include aluminum hydroxide, potassium alum, aluminum sulfate, aluminum glycinate, aluminum acetate, aluminum oxide, and aluminum oxide. Examples include polyvalent metal salts such as aluminum acid, magnesium chloride, aluminum hydroxide, and calcium carbonate, polyvalent metal hydroxides, and polyvalent metal oxides. Further, an epoxy compound can also be used.

The amount of these crosslinking agents can not be specified unconditionally depending on the type of the crosslinking agent, but it is usually preferably set to 0.1 to 5% by weight based on the total amount. If the amount of the cross-linking agent is too small, the cross-linking is not performed sufficiently, the retention of other components such as polyhydric alcohols and water is deteriorated, and the mechanical strength of the gel layer itself is reduced. On the other hand, if the compounding amount is too large, the resulting gel layer becomes too hard to crosslink, resulting in inferior flexibility, and also tends to decrease the retention of other components.

Of course, the water-containing gel layer contains various other water-soluble polymers, various inorganic and organic fillers such as silica, zinc oxide, calcium carbonate, hydroxyapatite, and carbon, flavors, and aloe extracts (liquids). ), Hamamelis extract (liquid), extracts (liquid) of various plants and animals such as hyaluronic acid, cooling agents such as l-menthol, antioxidants such as tocopherol acetate and BHT, paraoxybenzoic acid and esters thereof The anti-biological agent can be blended. In addition, besides these, moisturizing agents, whitening agents such as L-ascorbic acid, anti-wrinkle agents, and additives that can be blended into ordinary cosmetics such as various ultraviolet absorbers are used to determine whether they are active ingredients. It can be blended regardless of.

In the cosmetic gel sheet of the present invention, a release agent such as silicone can be applied to the back surface of the support, that is, the surface of the non-gel-impregnated layer, and subjected to a mold release treatment.

Further, at the time of marketing, it is cut into a predetermined size and shipped. Therefore, in this case, a separator is bonded to the exposed surface of the hydrogel layer in order to protect the exposed surface from dust and dirt. The separator is not particularly limited, and examples thereof include a polyethylene film, a polypropylene film, and a polyester film. By laminating the separator in this manner, the separator can be wound into a roll without performing a release treatment. Of course, it is needless to say that a release treatment is performed on the lamination surface of the hydrogel layer of the separator.

The cosmetic gel sheet of the present invention can be produced as follows. First, a water-soluble polymer such as acrylic acid is dissolved or suspended in water or an aqueous solution of alcohol. Next, additives such as various fillers, fragrances, and various animal and plant extracts are added and uniformly stirred. Thereafter, a polyvalent metal salt is added and the mixture is stirred, and the support is coated in a thin film using a coating machine. At this time, as a coating machine used, for example, a coating machine used for manufacturing an adhesive tape can be used as it is. For example, examples of such a coating machine include various roll coaters represented by a comma coater and various blade coaters represented by a Fonten blade coater.

At this time, the hydrogel layer is in the form of a thin film,
The thickness of the hydrogel layer is 2 mm or less, preferably 10 mm or less.
The coating is performed to a thickness of 00 μm or less, more preferably 200 to 500 μm. After coating the hydrogel layer in a thin film on the support in this manner, a separator is attached as necessary,
It is wound into a roll as it is, and if necessary, sealed with wrapping paper or the like, heated to about 50 ° C. and stored, and crosslinked to obtain a product.

Alternatively, after forming the hydrogel layer directly on the separator by a coating machine, the above-mentioned support may be adhered and wound up immediately in a roll. Even in this case, it is preferable to form the hydrogel layer into a thin film of 2 mm or less. Of course, it can be formed into a thick thick film by a conventional coating machine or the like.

As described above, in the present invention, using a two-layer support having a gel impregnated layer and a gel non-impregnated layer,
By forming the hydrogel layer into a thin film, it can be immediately wound into a roll to complete the crosslinking. In particular, it is possible to directly form a thin hydrogel layer on a support or the like by a coating machine, and after coating on the support, without drying in advance, it can be wound directly into a roll. It is convenient. Therefore, it is possible to efficiently produce a thin-film type cosmetic gel sheet with less variation in thickness while preventing strikethrough. In addition, since drying is not performed in advance, there is an advantage that a fragrance or the like is not volatilized during the manufacturing process and a volatile additive such as l-menthol can be further compounded.

[0040]

Next, the present invention will be described in more detail with reference to examples. (Production Example 1) After suspending 6 parts by weight of sodium polyacrylate, 4 parts by weight of crosslinked polyacrylic acid, and 0.1 part by weight of paraoxybenzoate in 40 parts of glycerin, 50 parts by weight of purified water and dry water A gel composition was obtained by mixing 0.3 parts by weight of aluminum oxide. After forming a film using a bar coater so that the gel thickness becomes about 1 mm on one side of a silicone film having a width of 30 cm and subjected to silicone treatment, various kinds of supports as shown in Table 1 are adhered to each other, and immediately formed into a roll. It was wound up continuously for 30 m. Thereafter, the roll was sealed with an aluminum sheet and aged at 50 ° C. for 3 days to obtain cosmetic gel sheets of Examples 1 to 4 and Comparative Examples 1 to 3. In addition, the nonwoven fabric surface or the pulp surface of the support was adhered to the hydrogel layer. These various cosmetic gel sheets were examined for completion of gelling and presence / absence of strike-through. As shown in Table 1, the gel sheets of each example were well gelled and show strike-through. Did not.

[0041]

[Table 1]

(Production Example 2) Sodium polyacrylate 6
4 parts by weight of cross-linked polyacrylic acid and 0.1 part by weight of paraoxybenzoic acid ester are suspended in 40 parts of glycerin, and then 50 parts by weight of purified water and 0.3 part by weight of dry aluminum hydroxide are mixed. Thus, a gel composition was obtained. This was formed into a polyester film having a width of 30 cm on one side by a silicone treatment and having a gel thickness of about 1 mm using a bar coater. After that, about 2,000 perforations per m ² (about 300 μm in diameter) were formed at 20 μm. The pulp surface of the support consisting of two layers of a thick polyethylene film and a pulp having a basis weight of 15 g / cm ² was bonded to the hydrogel layer, and immediately wound continuously in a roll form for 30 m. Thereafter, the roll was sealed with an aluminum sheet and aged at 50 ° C. for 3 days to obtain a cosmetic gel sheet of Example 5.
Even the cosmetic gel sheet was well gelled, and no strikethrough was observed.

Next, the cosmetic gel sheet having perforations on the support and the cosmetic gel sheet of Example 3 without perforations were cut into a size of 5 cm × 7 cm, respectively, and affixed to the calf of the foot. The cooling sensation was examined. As a result, in the case of the gel sheet having no perforations, the cooling sensation disappeared in about 5 minutes.
The cooling feeling was maintained for about 0 minutes. In both cases, the adhesiveness to the skin was good, and no adhesive residue was observed when peeled off from the skin.

[0044]

According to the present invention, the hydrogel layer is laminated on the gel-impregnated layer of the support consisting of the gel-impregnated layer and the gel-non-impregnated layer. Even when the cross-linking is aged, a cosmetic gel sheet having a small variation in thickness can be obtained without the penetration of the hydrous gel layer.

Further, by applying the hydrogel layer in a thin film form, the hydrogel layer can be formed on the support without drying in advance, and can be immediately wound into a roll. As a result, it is possible to form a film using a general coating machine used for the pressure-sensitive adhesive tape, and it is possible to dramatically improve the working efficiency. In addition, since the penetration of the hydrogel layer and the variation in the thickness of the hydrogel layer are reduced, the yield of cosmetic gel sheets, especially thin gel sheets, can be significantly prevented from lowering.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takako Ujiie 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation F-term (reference) 4C076 AA74 AA75 BB31 DD23 DD24 DD25 DD27 DD29 DD30 DD38 DD41 DD45 EE09A FF35 4C083 AB032 AB271 AC122 AC482 AD091 AD092 CC07 DD12 DD41 EE06 EE12

Claims (10)

[Claims] 1. A cosmetic gel sheet in which a water-containing gel layer is laminated on a sheet-like support, wherein the support comprises two layers: a gel non-impregnated layer and a gel-impregnated layer. A cosmetic gel sheet laminated on a gel-impregnated layer. 2. The cosmetic gel sheet according to claim 1, wherein the water-containing gel layer is in the form of a thin film. 3. The non-gel impregnated layer is a hydrophobic film or foam sheet, and the gel impregnated layer is a non-woven fabric,
The cosmetic gel sheet according to claim 1, which is any one of a woven fabric, a paper, and a hydrophilic film. 4. The cosmetic gel sheet according to claim 3, wherein the film of the gel non-impregnated layer is perforated. 5. The cosmetic gel sheet according to claim 3, wherein the film of the gel non-impregnated layer is a polyurethane film. 6. The cosmetic gel sheet according to claim 1, wherein the water-containing gel layer contains a carboxyvinyl polymer and is crosslinked with a polyvalent metal salt. 7. A step of mixing and stirring a polyvalent metal salt into a solution or suspension of a carboxyvinyl polymer, and then forming a hydrogel layer into a thin film using a coating machine; And applying heat in the wound state to ripen the gel. 8. The makeup according to claim 7, wherein the water-containing gel layer is formed on a separator, a support is attached to the formed water-containing gel layer, and then wound into a roll. Of producing gel sheet for use. 9. The cosmetic according to claim 7, wherein the hydrogel layer is formed on a support, a separator is attached to the formed hydrogel layer, and then wound into a roll. A method for producing a gel sheet. 10. The cosmetic gel sheet according to claim 9, wherein the support comprises two layers, a gel non-impregnated layer and a gel impregnated layer, and the hydrogel layer is laminated on the gel impregnated layer. Manufacturing method.