JP2006045148A - Method for producing gel composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing gel composition easily dispersing a hydrophilic high molecular compound and forming a homogeneous gel even in a formulation with reduced amount of polyhydric alcohol. <P>SOLUTION: The invention relates to the method for producing gel composition comprising reaction of the hydrophilic high molecular compound having carboxy group and a polyhydric alcohol after mixing or in mixing at a reaction temperature of 80-200°C for 0.1-20 hr and then mixing of the product of heating reaction with a cross linking agent to perform gelatinization and the invention relates to the method for producing gel composition comprising partial esterification of the hydrophilic high molecular compound having carboxy group with the polyhydric alcohol and then mixing and gelatinizing the reaction product with the cross linking agent and to the gel composition for hair remover. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a method for producing a gel-like composition, more specifically, a method for producing a gel-like composition containing a hydrophilic polymer compound having a carboxyl group, and a method for producing a gel-like composition for hair removal.

  The gel composition is used for external patches that have a medicinal effect on the surface of the body or a portion relatively close to the surface to expect a local effect, and crosslinks a formulation containing a hydrophilic polymer compound, water, and a crosslinking agent. Manufactured by doing.

  For example, Patent Document 1 uses a gel containing poly (meth) acrylic acid and / or a salt thereof or a copolymer thereof, and a gel sheet containing a keratin reducing compound such as thioglycolic acid as a hair removal component. A hair remover is disclosed. The gel sheet-like depilatory agent has the advantage that it can be processed in a short time with a simple operation of being applied directly to the depilation part, and the odor of the drug can be removed without concern.

  In this case, in order to satisfy that the medicinal component of the applied gel acts uniformly on the skin, that the gel has excellent adhesion to the skin, and that the gel can be peeled cleanly, the gel is uniformly mixed. Need to be.

  However, in the production of a gel composition, when a hydrophilic polymer compound is dissolved in a large amount of water, the dissolved polymer viscous part wraps the undissolved powder part, and the dissolution rate is significantly reduced. Is easy to form. In order to avoid this, it is known to use a method in which powder is slowly put into a medium under high-speed stirring. However, this method is not economically disadvantageous because it cannot completely suppress “mamako”, merely reduces the amount of the product produced, and requires a long time for dissolution.

  Patent Document 2 discloses an external patch containing a water-soluble polymer substance having a carboxyl group or a salt thereof and a polyhydric alcohol. Patent Document 2 describes that polyhydric alcohol plays a good role as a dispersion medium for water-soluble polymers in the patch manufacturing process. Sodium polyacrylate, CMC-Na and methylparaben are dispersed in concentrated glycerin. A method for preparing a paste by preparing a glycerin paste and kneading other ingredients is described.

However, in order to obtain good dispersibility using a polyhydric alcohol, it is necessary to blend a certain amount of polyhydric alcohol. Patent Document 2 also describes that the blending amount is 5 to 50% by mass, preferably 10 to 40% by mass.
JP 2002-293723 A Japanese Patent Laid-Open No. 2002-20274

  However, when a large amount of polyhydric alcohol is blended, the blending amount of other components, particularly medicinal components, is lowered, and as a result, there is a problem that the effect is reduced. In order to maintain the effect of the medicinal component, it is necessary to reduce components other than the medicinal component, which is not preferable from the viewpoint of the stability of the blend. In addition, the presence of the polyhydric alcohol may reduce the effect of the medicinal component. In such a case, it is required to reduce the blending amount of the polyhydric alcohol as much as possible.

  The present invention provides a method for easily dispersing a hydrophilic polymer compound even in a reduced blending amount of a polyhydric alcohol to produce a uniform gel composition.

  In the present invention, after mixing or mixing a hydrophilic polymer compound having a carboxyl group and a polyhydric alcohol, a heat treatment is performed under conditions of a reaction temperature of 80 ° C. to 200 ° C. and a reaction time of 0.1 to 20 hours. Then, the resulting heat-reaction product is mixed with a crosslinking agent and gelled, and the method for producing a gel-like composition and the hydrophilic polymer compound having a carboxyl group are partially mixed with a polyhydric alcohol It is related with the manufacturing method of the gel-like composition which mixes the obtained reaction product with a crosslinking agent after esterification, and gelatinizes, and the gel-like composition for hair removal obtained by this method.

  According to the present invention, even if the blending amount of the polyhydric alcohol is reduced, it is possible to suppress the formation of “mamako” that is likely to occur during the production of the gel composition blended with the hydrophilic polymer compound. A uniform gel composition can be easily obtained.

<Combination raw material>
<Hydrophilic polymer compound>
The hydrophilic polymer compound used in the present invention is a polymer compound having a carboxyl group, for example, a polymer containing (meth) acrylic acid as a monomer unit or a crosslinked product thereof, a cellulose derivative or a crosslinked product thereof, Examples include semi-synthetic polymer compounds such as starch derivatives (for example, carboxymethyl starch) and polysaccharide derivatives, and one or more of these can be used.

As a polymer containing (meth) acrylic acid as a monomer unit, (meth) acrylic acid / (meth) acrylic acid ester copolymer and salt thereof, (meth) acrylic acid / maleic acid copolymer and salt thereof, Examples include starch-acrylic acid graft copolymers and salts thereof.
Examples of the cellulose derivative include carboxymethyl cellulose and salts thereof (for example, sodium salt and potassium salt).

<Molecular weight>
The molecular weight of the hydrophilic polymer compound having a carboxyl group is preferably 10,000 or more in terms of weight average from the viewpoint of ease of gel formation and miscibility with medicinal ingredients, and is more preferably 10,000 to 10,000,000. preferable. Further, the hydrophilic polymer compound may be a mixture of two kinds of molecular weights, for example, a polymer compound having a molecular weight of 1,000,000 or less and a polymer compound having a molecular weight of more than 1,000,000. It is possible to provide appropriate adhesion to the skin, which is preferable.

<Blending amount>
The blending amount of the hydrophilic polymer compound having a carboxyl group improves the retention of other components such as water and medicinal ingredients, improves the mechanical strength of the gel composition itself, and also provides a gel-like form. From the viewpoint of imparting excellent flexibility to the composition, it is preferably 3 to 50% by weight, more preferably 5 to 30% by weight, and particularly preferably 5 to 20% by weight in the gel composition.

<Polyhydric alcohol>
Examples of the polyhydric alcohol used in the present invention include polyethylene glycol, propylene glycol, polypropylene glycol, glycerin, polyglycerin, sorbitol, and 1,3-butanediol. Among them, propylene glycol and glycerin are gel preparations. It is preferable in terms of simplicity and stability. The polyhydric alcohol can use 1 type (s) or 2 or more types. The blending amount of the polyhydric alcohol is preferably 0.1 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, and still more preferably 0.1 to 4 parts by weight with respect to 100 parts by weight of the entire gel composition.

  The blending amount of the polyhydric alcohol is preferably 1 to 200 parts by weight, more preferably 2 to 50 parts by weight, and further preferably 5 to 20 parts by weight with respect to 100 parts by weight of the hydrophilic polymer compound having a carboxyl group. .

<Manufacturing process>
<Heat treatment>
In the present invention, a hydrophilic polymer compound having a carboxyl group and a polyhydric alcohol are mixed, and then heat treatment is performed. At this time, the carboxyl group and the hydroxyl group of the polyhydric alcohol are partially esterified.

  Prior to the heat treatment, the hydrophilic polymer compound having a carboxyl group and the polyhydric alcohol may be mixed in advance to obtain a polymer composition. At this time, uniform dispersion can be more easily realized by adding an appropriate solvent. As a suitable solvent, a solvent having an affinity for a polyhydric alcohol, such as methanol, ethanol, an aqueous ethanol solution, or the like is preferably used. These solvents may be removed by an appropriate method such as distillation after uniform mixing is realized. Prior to the heat treatment, a medicinal component and other components may be mixed.

  The heat treatment is preferably performed before adding the cross-linking agent in order to more efficiently suppress the production of “mamakoko”. When the polyhydric alcohol also serves as a cross-linking agent described later, the total amount of the polyhydric alcohol to be blended may be mixed before the heat treatment, or a part thereof may be mixed before the heat treatment, and the remaining amount You may mix after heat processing.

  The conditions for the heat treatment can be appropriately set as long as the carboxyl group of the hydrophilic polymer compound and the polyhydric alcohol are esterified to cause dehydration, but the reaction temperature is preferably 80 to 200 ° C., 100 -150 degreeC is more preferable. Although reaction time is dependent on reaction temperature, 0.1 to 20 hours are preferable and 1 to 12 hours are more preferable. Although the reaction pressure is not particularly defined, it is preferably carried out under reduced pressure conditions in order to promote dehydration.

  The esterification rate is preferably 2 to 95 mol% of the carboxyl group of the hydrophilic polymer compound and more preferably 5 to 50 mol%. Within this range, the occurrence of “mamako” can be effectively suppressed, but this is because the carboxyl group in the polymer is partially esterified, so that the water absorption of the polymer is lowered and the swelling property is suppressed. Estimated.

Here, the esterification rate is obtained by calculating the amount of polyhydric alcohol decreased by esterification from the polymer composition with 85% ethanol aqueous solution and quantifying by gas chromatography, and then calculating according to the formula (I). Can be sought.

Esterification rate (mol%) = (mol number of polyhydric alcohol decreased by reaction) / (mol number of carboxyl group before esterification) × 100 (I)

The progress of esterification can also be confirmed by the decrease in polyhydric alcohol before and after the heat treatment.

<Preparation of gel composition>
A gel composition is prepared by blending a heat-treated polymer composition with a crosslinking agent, water, and other components.

<Crosslinking agent>
Examples of the crosslinking agent include a covalent bonding agent and an ionic bonding agent.
Examples of the covalent crosslinking agent include polyhydric alcohols such as dialcohol and trialcohol; bifunctional substances such as dimethylolurea and epichlorohydrin. The polyhydric alcohol added for esterification with the hydrophilic polymer compound can also serve as a crosslinking agent.
Examples of the ion-bonding crosslinking agent include polyvalent amines such as diamine, triamine, and polyamine and salts thereof; polyvalent metal hydroxide, polyvalent metal oxide, polyvalent metal salt (polyvalent metal inorganic salt and polyvalent metal salt). Metal organic salts) and the like.

<Water>
The water content of the gel composition of the present invention improves the mechanical strength of the gel composition itself while improving the retention of water, medicinal components, and other components, and the resulting gel composition From the viewpoint of improving the flexibility of the product, it is preferably 30% by weight or more, more preferably 30 to 90% by weight, and particularly preferably 30 to 85% by weight.

<Combination of other ingredients>
In the gel composition of the present invention, other components that are usually used in cosmetics, for example, activators, foaming improvers, solvents, polyols, lower alcohols, oils, thickeners, moisturizers, as necessary. Agent, wetting agent, feel improver, flame retardant, ultraviolet absorber, antioxidant, antiseptic, bactericidal agent, antibacterial agent, powder, fragrance, coloring matter, coloring pigment, pearlizing agent, warming sensation agent, chelating agent, Medicinal components, propellants, pH adjusters, deodorants, and the like can be blended within a range that does not impair the effects of the present invention.

<PH>
The pH of the gel composition of the present invention can be appropriately adjusted with a pH adjuster. The liquidity may be alkaline, neutral or acidic.

<The manufacturing method of the gel-like composition for hair removal>
A gel-like composition for hair removal is manufactured by mix | blending a crosslinking agent, water, and a keratin reducing compound with the polymer composition which heat-processed.

<Keratin reducing compound>
As the keratin-reducing compound, at least one selected from various compounds that reductively cleave keratin protein in hair can be used. Examples of such keratin reducing compounds include thioglycolic acid, cysteine, and derivatives thereof, and salts thereof. Here, as derivatives of thioglycolic acid, thioglycolic acid monoglyceryl ester and the like, and as cysteine derivatives, N-acylcysteine, particularly N-acylcysteine whose acyl group is an alkylyl group having 1 to 10 carbon atoms, etc. It can be illustrated. Examples of salts of thioglycolic acid, cysteine, or derivatives thereof include alkali metal salts such as ammonium salts, quaternary ammonium salts, sodium salts, and potassium salts, and alkaline earth metal salts such as calcium salts and magnesium salts. , Mono-, di-, tri-ethanolamine salts, basic amino acids and the like.

  The blending amount of the keratin-reducing compound is appropriately determined depending on the type of the compound, etc., but when blending cysteine, N-acylcysteine or thioglycolic acid, from the viewpoint of obtaining sufficient hair removal performance and preventing rough skin, 0.5-30 weight% is preferable in the gel-like composition for hair removal, and 1-20 weight% is still more preferable.

<PH of the gel-like composition for hair removal>
The pH value of the hair-removal gel composition of the present invention is appropriately determined according to the type of keratin-reducing compound, the blending amount, the presence or absence of addition of alcohols, and the like. When thioglycolic acid or a salt thereof is added to the hair removal composition of the present invention, pH 8 to 13 is preferable from the viewpoint of improving hair removal performance and reducing skin irritation, and 9 to 13 Is more preferable, and 10 to 13 is particularly preferable. The pH can be adjusted with an alkali metal hydroxide such as potassium hydroxide or sodium hydroxide.

  Under such conditions, an ester compound generally easily undergoes hydrolysis and is decomposed into a hydrophilic polymer compound and a polyhydric alcohol, which are the original components. However, according to this method, since all the decomposition products were originally planned to be incorporated into the hair-removal gel composition, there is no inconvenience.

<Crosslinking agent>
As the cross-linking agent, one or more of the above-mentioned covalent cross-linking agents and ionic cross-linking agents can be used, but ionic cross-linking agents are preferred, and polyvalent metal hydroxides and polyvalent metals. Oxides and polyvalent metal salts (polyvalent metal inorganic salts and polyvalent metal organic salts) are more preferred. Since the time required for crosslinking, that is, the time until gelation is appropriate, polyvalent metal hydroxides and polyvalent metal oxides are more preferable, and aluminum hydroxide and calcium hydroxide are particularly preferable.

  The amount of the cross-linking agent varies depending on the type of cross-linking agent. However, sufficient cross-linking is performed to improve the retention of other components such as water and medicinal components, and the mechanical strength of the gel composition itself is improved. In addition, from the viewpoint of giving an appropriate flexibility, 0.05 to 10% by weight is preferable in the gel composition, and 0.1 to 5% by weight is more preferable.

<Combination of other ingredients>
Furthermore, in order to improve the stability of the gel, a nonionic hydrophilic polymer compound and water-insoluble particles can be blended. The “water-insoluble” of the water-insoluble particles means that when 1 part by weight of the target particles is dissolved in 99 parts by weight of water at 25 ° C., the solubility is 50% by weight or less. The solubility is calculated from the solid content during filtration of the aqueous solution with a filter paper (No. 2).

  Further, the gel-like composition for hair removal of the present invention preferably contains a penetration enhancer for the purpose of further increasing the penetration rate of the keratin reducing compound into the hair and improving the hair removal ability. A plasticizer can be used from the viewpoint of adjusting the viscosity and viscosity, or various fillers can be used from the viewpoint of reinforcing the gel.

  In addition, the raw materials used for blending the gel composition for hair removal of the present invention are made of iron, etc. in order to prevent deterioration of hue, deterioration of odor, alteration of keratin reducing substances, etc., and improve storage stability. Those having a low metal content are preferred.

<Viscosity of gel>
The gel-like composition for hair removal of the present invention has a viscosity of 25 ° C., spindle No.TF, TD, TE of a helical viscometer (manufactured by TOKI SANGYO.CO.LTD), rotational speed 0. 5-5 r / min The value when measured under conditions of 3 minutes is preferably 100,000 mPa · s or more, more preferably 300,000 mPa · s or more, and 500,000 mPa · s or more. It is particularly preferred. The upper limit is preferably 20 million mPa · s or less, more preferably 15 million mPa · s or less, and particularly preferably 10 million mPa · s or less. Within the range of 100,000 to 20 million mPa · s, droplets are not generated from the gel or the gel does not become too hard, and the moldability is good and the sheet is easily formed.

<Dosage form>
There is no restriction | limiting in particular as a dosage form of the gel-like composition for hair removal of this invention, Since it is gel-like, it can be used as it is and the gel-like composition for hair removal is on a support body and / or as needed. Or it can also be used as a gel sheet for hair removal which has in a support body.

  The method of applying a gel-like composition for hair removal to a sheet such as a non-woven fabric when it is present on a support, or a book containing a keratin reducing compound and a crosslinking agent on a sheet such as a non-woven fabric when it is present in a support. There is a method of applying and immobilizing the polymer composition according to the invention before gelation.

  A non-breathable release film is stuck on the surface of a gel stuck or fused to a sheet such as a non-woven fabric, and a pouch or pillow made of a non-breathable laminate or the like, which can be opened and closed and sealed. The form put in a thing is preferable because the stability of the gel can be maintained. At the time of use, since it can take out from the sealed bag, peel off the release film, and directly apply the gel-like composition for hair removal to the hair removal site, the operation is the easiest and preferable.

  Moreover, when using a sheet | seat, leaving all the periphery of a sheet | seat, a part periphery part, or four corners, it is preferable on operability not to get a hand dirty, but to have the gel-like composition for hair removal on a sheet | seat. When the gel-like composition for hair removal exists on a sheet | seat, the thickness of 0.01-5 mm is preferable and the thickness of 0.05-3 mm is still more preferable. Moreover, when using the gel-like composition for hair removal as it is, the thickness of 0.5-10 mm is preferable and the thickness of 1-5 mm is still more preferable.

[Support]
The support used in the hair removal gel sheet according to the present invention may be moisture permeable or non-or hardly moisture permeable. The structure may be any as long as it has water resistance and can withstand pasting and peeling, and as a support having moisture permeability, a sheet or film such as a woven fabric, a nonwoven fabric, a porous film, a gas permeable film, and the like The laminated body of this is mentioned. Since the sheet and the film are distinguished only by the thickness of the layer, the film is included in the sheet. From the viewpoint of formability, a sheet made of a nonwoven fabric is more preferable. In order to suppress the chemical odor during use, to prevent drying, and to prevent the active ingredient from evaporating, a non-or hardly moisture-permeable support is preferable. Examples of the non-or hardly moisture-permeable support include a laminated sheet obtained by laminating polyethylene or the like on a nonwoven fabric or paper.

  Materials of support are polyester, nylon, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polytetrafluoroethylene, ionomer, polyacrylonitrile resin , Sheets using one or more of various synthetic fibers such as polyurethane, cellulose, rayon and acetate, paper, cloth and the like.

  The thickness of the support of the present invention is preferably 0.01 to 5 mm, more preferably 0.1 to 3 mm, and particularly preferably 0.1 to 2 mm.

[How to use gel-like composition for hair removal]
When using the gel-like composition for hair removal of the present invention, the gel-like composition for hair removal is affixed to the hair removal site, and preferably left for 2 to 20 minutes, more preferably for 3 to 15 minutes. The compound penetrates into the hair and is reduced. In the middle, the gel can be peeled off a little to confirm the swelling state of the body hair. Thereafter, the gel is peeled off, and the agent is removed together with the body hair cut by washing with water or wiping. The hair removal part can be applied to all parts that use commercially available hair removers such as arms, legs, armpits, bikini lines, etc. Furthermore, it is very easy to use and has low odor, so it can be used on the face (eyebrows, eyelids, vellus hair) It is also possible to apply to.

  Examples of the present invention will be described below. In the following, “parts” means “parts by weight” unless otherwise specified.

Example 1
(Preparation of polymer composition)
In a 300 mL eggplant flask, 5 g of glycerin and 150 g of 85% ethanol aqueous solution are mixed, 27.5 g of partially neutralized sodium polyacrylate (Nippon Pure Chemicals, Aronbis AH, 70% neutralized product), polyacrylic acid (Nippon Pure Chemical) Manufactured, AC-10LHP) 7.5 g and sodium carboxymethylcellulose (Nippon Paper Industries, F30LC) 10.0 g were sequentially added and mixed at 65 ° C. for 1 hour using a rotary evaporator, and then ethanol was distilled off under reduced pressure.
(Heat treatment)
The obtained water-containing mixture was transferred to a stainless steel vat, and a heat treatment reaction was performed in a vacuum dryer at a pressure of 30 kPa and a temperature of 120 ° C. for 12 hours to obtain a polymer composition.
(Preparation of gel composition)
10 g of the polymer composition obtained in the above step (B) is mixed with 0.1 g of aluminum hydroxide (produced by Kyowa Chemical Co., Ltd., dry aluminum hydroxide gel FM) as a crosslinking agent and 4 g of calcium thioglycolate as a keratin reducing compound. A 5N aqueous sodium hydroxide solution and water were added to obtain 100 g of a gel composition A1 for hair removal having a pH of 12. The glycerin content in the hair-removal gel composition was 1% by weight.

Example 2
A gel-like composition A2 for hair removal was obtained in the same manner as in Example 1 except that the heat treatment conditions of Example 1 were 30 kPa, 120 ° C., and 8 hours. The glycerin content in the hair-removal gel composition was 1% by weight. After the heat treatment, it was confirmed by gas chromatography that 50% by weight of the charged glycerin was esterified. From this, it was calculated that 14 mol% of the carboxyl groups in the hydrophilic polymer compound were esterified.

Example 3
A gel-like composition A3 for hair removal was obtained in the same manner as in Example 1 except that the heat treatment conditions of Example 1 were 30 kPa, 120 ° C., and 5 hours. The glycerin content in the hair-removal gel composition was 1% by weight.

Example 4
A gel-like composition A4 for hair removal was obtained in the same manner as in Example 1 except that the heat treatment conditions of Example 1 were 30 kPa, 130 ° C., and 8 hours. The glycerin content in the hair-removal gel composition was 1% by weight. After the heat treatment, it was confirmed by gas chromatography that 73% by weight of the charged glycerin was esterified. From this, it was calculated that 20 mol% of the carboxyl groups in the hydrophilic polymer compound were esterified.

Comparative Example 1
(Preparation of polymer composition)
1 g of glycerin, 5.5 g of partially neutralized polyacrylic acid sodium salt, 1.5 g of polyacrylic acid, and 2.0 g of sodium carboxymethylcellulose were mixed at 50 ° C. for 10 minutes using a hybrid mixer (manufactured by Keyence Corporation).
(Preparation of gel composition)
Thereafter, 10 g of the mixture obtained in the preparation process of the polymer composition was subjected to heat treatment without using 0.1 g of aluminum hydroxide (produced by Kyowa Chemical, dry aluminum hydroxide gel FM) as a crosslinking agent, and as a keratin-reducing compound. The mixture was mixed with 4 g of calcium thioglycolate, 5N aqueous sodium hydroxide solution and water were added, and 100 g of pH 12 gel-like composition B1 for hair removal was obtained. The glycerin content in the hair-removal gel composition was 1% by weight.

Comparative Example 2
A gel-like composition B2 for hair removal was obtained in the same manner as in Example 1 except that the heat treatment conditions of Example 1 were 30 kPa, 50 ° C., and 12 hours. The glycerin content in the hair-removal gel composition was 1% by weight.

<Evaluation result of gel>
The uniformity of the obtained gel composition for hair removal was visually observed, and the results are shown in Table 1.

  The gel-like composition for hair removal obtained in the examples was a “uniform gel” with no “mamako”. On the other hand, in the gel composition for hair removal obtained in the comparative example, a lot of “makko” remained, and the powder was not uniformly dispersed.

Example 5
The gel composition A1 for hair removal is applied to a polypropylene nonwoven fabric having a thickness of 0.5 mm and 3.0 cm × 2.5 cm to a thickness of 1 mm, placed in a sealed container, and placed in a thermostatic bath at 50 ° C. The gel was stabilized for a time to prepare a hair remover gel sheet.

Example 6
A hair remover gel sheet was prepared in the same manner as in Example 5, except that the hair removal gel composition A3 was used instead of the hair removal gel composition A1.

Comparative Example 3
A hair remover gel sheet was prepared in the same manner as in Example 5, except that the hair removal gel composition B1 was used instead of the hair removal gel composition A1.

Comparative Example 4
A hair remover gel sheet was prepared in the same manner as in Example 5 except that the hair removal gel composition B2 was used instead of the hair removal gel composition A1.

  The performance evaluation of the hair-removal agent gel sheets obtained in Example 5, Example 6, Comparative Example 3, and Comparative Example 4 was performed by the following method.

[Hair removal performance]
The hair length of the front leg shin part of a male panelist (1 person) was cut to 1 cm or less, and the number of hairs of 1 mm or more and 1 cm or less in the range of 2.5 cm × 2.5 cm was counted. Next, a non-woven fabric to which the gel-like composition for hair removal was applied was applied within this range, left for 10 minutes, peeled off, and wiped with cotton. Thereafter, the number of hairs of 1 mm or more remaining without hair removal was counted, and the hair removal rate was determined by the following formula (1).

Hair removal rate (%) = (number of body hairs before hair removal−number of body hairs remaining after hair removal) / number of body hairs before hair removal × 100 (1)

[Adhesiveness of hair remover gel sheet]
The state of adhesion to the skin 10 minutes after application was evaluated by observation.

<Evaluation results of hair remover gel sheet>
The evaluation results of each hair remover gel sheet are shown in Table 2.

  The surfaces of the gel sheets of Examples 5 and 6 were uniform, and no peeling occurred after 10 minutes. The hair removal rates were as high as 97% and 95%, respectively, indicating that the active ingredient was acting on the entire applied surface.

The gel sheets of Comparative Examples 3 and 4 had granular lumps in some places, and the sheet surface was irregular. The hair removal rate of Comparative Example 3 was as low as 58%, and the hair removal rate of Comparative Example 4 was as low as 65%, indicating that only a portion of the attached gel sheet had an effect.

Claims (8)

After mixing or mixing the hydrophilic polymer compound having a carboxyl group and the polyhydric alcohol, the reaction temperature is 80 ° C. to 200 ° C., and the reaction time is 0.1 to 20 hours. The manufacturing method of the gel-like composition which mixes the obtained heat-reaction product with a crosslinking agent, and performs gelatinization.
The method for producing a gel composition according to claim 1, wherein the hydrophilic polymer compound having a carboxyl group and the polyhydric alcohol are heat-treated, and then the keratin reducing compound is mixed.
A method for producing a gel-like composition, in which a hydrophilic polymer compound having a carboxyl group is partially esterified with a polyhydric alcohol, and then the resulting reaction product is mixed with a crosslinking agent for gelation.
The method for producing a gel composition according to claim 3, wherein the hydrophilic polymer compound having a carboxyl group is partially esterified with a polyhydric alcohol, and then the keratin reducing compound is mixed.
The method for producing a gel composition according to claim 2 or 4, wherein the pH is adjusted to 8 to 13 after mixing the keratin reducing compound.
The gel composition according to any one of claims 1 to 5, wherein the hydrophilic polymer compound having a carboxyl group is a polymer compound containing methacrylic acid (salt) and / or acrylic acid (salt) as a monomer unit. Manufacturing method.
The manufacturing method of the gel-like composition in any one of Claims 1-6 whose compounding quantity of a polyhydric alcohol is 0.1-20 weight% of all the gel-form composition raw materials.
It is a gel-like composition, Comprising: The gel-like composition for hair removal manufactured with the manufacturing method in any one of Claims 1-7.