JPS60202103A - Cosmetic additive - Google Patents

Abstract

PURPOSE:An additive having excellent humectant effect and affinity for the skin and allowing good spreading of a cosmetic, comprising a modified vinyl alcohol having an alkyl sulfoxide group in the molecule. CONSTITUTION:An additive comprising a modified polyvinyl alcohol containing an alkyl sulfoxide group in the molecule. Said alcohol can be produced by, for example, a process comprising an addition reaction between the corresponding alkyl vinyl sulfoxide and a hydroxyl group of polyvinyl alcohol, or a process comprizing saponification of a copolymer obtained by copolymerizing an alkyl vinyl sulfoxide with a vinyl ester such as vinyl acetate. Among them, the latter is desirable because a highly modified PVA of a high degree of polymerization can be easily obtained. As the modified polyvinyl alcohol, one having a content of alkyl sulfoxide group-containing units of 5-80mol% based on the total structural units is generally used.

Description

[Detailed Description of the Invention] A1 The present invention relates to a novel additive for cosmetics consisting of modified polyvinyl and alcohol containing an alkyl nulphoxyto group in the molecule. When added to cosmetics such as hair conditioners, lotions, hair sprays, and hair creams, when hair is treated, it has excellent hair finishing effects with excellent shine and curl retention, as well as hand creams. The present invention relates to a cosmetic additive that provides firmness, sensitivity, and smoothness when applied to the skin as a pack, foundation, etc.

B. Prior art and its problems Conventionally, many additives have been used or proposed in cosmetics for the purpose of imparting appropriate moisture to hair or skin debris. For example, higher alcohols, lanolin, higher fatty acid esters, protein decomposition products, glycerin,
Polyethylene glycol, polyvinyl alcohol, polyvinylpyrrolidone, hydroxyethylcellulose, sodium polyacrylate, carboxymethylcellulose,
Examples include polyisobutylene.

However, these products are not necessarily effective in terms of affinity and moisturizing for hair and skin.
There is a need for additives for cosmetics that have a high affinity for skin and provide a high degree of moisture.

C1 Structure, purpose, and effect of the present invention The present inventors have conducted intensive research to develop a water-soluble polymer that can be blended into cosmetics to provide an excellent feeling of use. Modified polyvinyl alcohol containing,
In particular, the content of alkyl sulfoxide groups (the content i or less of units containing alkyl sulfoxide groups based on the total amount of the modified polyvinyl alcohol constituent units, referred to as the degree of modification) is 5 to
It has been discovered that a cosmetic additive comprising modified polyvinyl alcohol of 80 mol%, preferably 10 to 50 mol%, is excellent for this purpose, and has led to the completion of the present invention.

Conventionally, polyvinyl 7 modified with alkyl sulfoxide groups
The concept of using μcol in cosmetics is completely unknown. However, cosmetics containing cosmetic additives made of modified polyvinyl alcohol with a high degree of modification of alkyl sulfoxide groups, particularly with a degree of modification of 5 to 80 mol%, preferably 10 to 50 mol%, have poor wettability. excellent,
Moreover, it was discovered that it has excellent affinity for the skin and is good for use in cosmetics. Furthermore, the additive for cosmetics of the present invention has both the excellent film-forming properties inherent to modified PVA and the ability to impart suspension and dispersion stability to cosmetics. Furthermore, the cosmetic additive of the present invention does not cause any adverse effects such as irritation even when used regularly on the skin.

D1 More detailed description of the present invention The modified polyvinyl alcohol containing alkyl sulfoxide Modified polyvinyl alcohol-A/T containing a group represented by (preferably 1 to 4 alkyl groups),
A method of adding alkyl vinyl sulfoxide to the hydroxyl group of polyvinyl alcohol/L/ (hereinafter abbreviated as PVA), or saponification of a copolymer obtained by copolymerizing alkyl vinyl sulfoxide with a vinyl ester such as vinyl acetate. It can be manufactured by any method.

These manufacturing methods are described in detail in Japanese Patent Application No. 58-94669 and Japanese Patent Application No. 58-29956, both of which were filed by the present inventors. It is preferable that it can be easily obtained.

First, we will explain how to add an alkyl vinyl sulfoxide to the hydroxyl group of PvA. H or methyl group, preferably H. ) unit, which includes all polymers such as homopolymers, ordinary copolymers, block copolymers, graft polymers, and post-reaction polymers such as formal and butyralized polymers. Among these, PVA is obtained by polymerizing and saponifying vinyl esters such as vinyl acetate, or by copolymerizing vinyl esters such as vinyl acetate with comonomers such as ethylene, alkyl vinyl ether, methyl acrylate, itaconic acid, maleic anhydride, etc. , PVA obtained by saponification is preferred. Since the unsaponified residual vinyl ester units of PVA consume the alkali compound of the catalyst used in the reaction with the alkyl vinyl sulfoxide, the degree of saponification of the vinyl ester units is preferably high, and is preferably 50 mol % or more, preferably 80 mol %. % or more is desirable.

Further, the degree of polymerization of these PVAs or PVAs is not particularly limited, but is 200 to 4,000, preferably 300 to 3,000. There is no particular limit to the form of reaction of PVA with alkyl vinyl sulfoxide, and it may be in any form such as solution, melt, powder, film, fiber, foam, etc. As the alkyl vinyl sulfoxide, methyl vinyl/I/ Suitable examples include sulfur μyl vinyl sulfoxide having an alkyl group having 1 to 10 carbon atoms, such as nurphoxide, ethyl vinyl sulfoxide, butyl vinyl sulfoxide, cyclohexyl vinyl sulfoxide, and benzyl vinyl sulfoxide, among which methyl, ethyl, Lower alkyl vinyl sulfoxides having 1 to 4 carbon atoms, such as butyl, have good reactivity and are preferable.

The reaction between PVA and alkyl vinyl sulfoxide is not particularly limited and may be any reaction as long as both substances can undergo a catalytic reaction. But usually PVA? Solution method of reacting with alkyl vinyl sulfoxide in aqueous solution, PVA
When PVA is water-insoluble, a water-based reaction such as a method in which PVA is brought into contact with an alkyl vinyl sulfoxide-containing aqueous solution by immersion is preferred because of its high reaction rate. In addition, dioxane, tetrahydrofuran, diethyl ether ρ, acetone,
Polar solvents such as dimethy/l/sulfoxide, dimethylformamide, formamide, etc. can also be used. Other solvents can also be used as long as they do not inhibit the reaction.

PVA! : In the reaction with an alkyl vinyl sulfoxide, an alkali, usually an alkali metal hydroxide, is used as a reaction catalyst, with sodium hydroxide and potassium hydroxide being particularly preferred. Further, the alkaline concentration is preferably 0.005 to 5, preferably 0.01 to 3 in molar ratio to the hydroxyl group of PVA. If the molar ratio is less than 0.005, the reaction rate will be low, and if the amount of alkali is too large, side reactions such as decomposition of the polymer or coloring will occur, which is not preferable.

The reaction temperature and time are determined as appropriate, taking into consideration the desired reaction rate, shape retention of the reactants, etc., but from the viewpoint of an appropriate reaction rate and side reactions such as decomposition and coloring of the polymer, the reaction temperature is 20 The temperature is 100°C to 100°C, preferably 30 to 85°C, and the reaction time is 1 minute to 10 hours, preferably 30 minutes to 5 hours.

After the reaction, the unreacted alkyl vinyl sulfoxide, catalyst, etc. are usually separated and purified by washing or the like, and then the product is post-treated by drying.

The introduction of alkyl sulfoxide groups can be controlled by adjusting the reaction conditions described above.

Next, a method for saponifying the 11-coyF' remer obtained by copolymerizing an alkyl vinyl nurphooxide and a vinyl ester such as vinyl acetate will be described. By mixing a general formula and a polymerization initiator with a vinyl ester such as vinyl acetate and polymerizing the mixture, a polyvinyl μ-Nether copolymer can be obtained.

The polymerization method may be either a batch method or a continuous method, but in the case of a batch method, the comonomer reactivity ratio (r+, r
It is well known that the monomer composition changes with the polymerization rate according to g), but in the so-called half-batch method, one or both monomers are added so that the monomer composition remains constant. It is desirable to employ this method in order to obtain a copolymer having a uniform copolymer composition. In the case of continuous multi-column copolymerization, for the same reason, it is desirable to add monomers to the second and subsequent columns so that the monomer composition in each column is constant. As a polymerization initiator, 2.2'-azobisisobutyronitri/l/(AIBN), 1.1'-
7zobi7-(cyclohexane-1-carbonitrile),
2.2'-Azobia, -(2,4-dimethylhaleronitri iv), 2. l-azobis-(4-methoxy-2,4
-dimethylpaleronitrile IV), 2,2'-azobis-
Reduction with known radical polymerization initiators and peroxides such as (2-amidinopropane) dibasic acid, benzoyl peroxide, potassium persulfate, ammonium persulfate, t-butyl hydroperoxide, dimo-butylcumene hydroperoxide, etc. The drug can be used to treat so-called urinary and dox-induced diarrhea. An appropriate temperature for the polymerization reaction is selected depending on the type of initiator, but 40-80°C is usually selected. In addition, a degree of polymerization regulator such as acetaldehyde or alkyl p-mercabutane may be added to the polymerization system. The rate of polymerization of the monomers is determined as appropriate depending on the purpose, such as economical efficiency and adjustment of the degree of polymerization. In the present invention, bulk polymerization without using a solvent is preferred because of its high polymerization rate, but other methods such as solution polymerization, suspension polymerization, and emulsion polymerization can also be used. After the copolymerization is completed, tJIK in which vinyl ester monomers such as vinyl acetate remain in the reaction solution must be separated and removed by distillation or the like. Even if vinyl sulfoxide remains, it is preferable to remove it, but in normal cases, the copolymerizability (γ2) of vinyl sulfoxide is higher than the copolymerizability (r]) of vinyl ester monomers such as vinyl acetate. The amount of vinyl sulfoxide remaining in the polymerization system is small.

In addition, in carrying out such polymerization, in addition to vinyl ester monomers such as vinyl acetate and vinyl nurphooxide, other unsaturated monomers that can be copolymerized with these monomers, such as α-olefins such as ethylene and propylene, are used. + Unsaturated acids such as (meth)acrylic acid, crotonic acid, maleic anhydride, fumaric acid, itaconic acid, or their alkyl μ
Este A/Salt; Unsaturated amides such as (meth)acrylamide and N-methylolacrylamide; Sulfonic group-containing monomers such as 2-acrylamide-2-methylpropane nulphonic acid or its salts, etc., are added to the modified PVA of the present invention. It is free to coexist and polymerize in an amount that does not impair the properties.

Next, modified PVA is produced by the following method. That is, the polyvinyl ether copolymer such as modified polyvinyl acetate obtained by the above-described method can be converted to CΦ by a conventional method. The saponification reaction is usually advantageously carried out as a solution of the copolymer in alcohol and then in methanol. Not only anhydrous alcohols but also those containing a small amount of water can be used depending on the purpose, and organic solvents such as methyl acetate and ethyl acetate may be optionally contained. As a saponification agent, sodium hydroxide,
An alkali metal hydroxide such as potassium hydroxide, an alcoholade such as sodium methylate or potassium methylate, an alkali catalyst such as ammonia, or an acidic catalyst such as diluted sulfuric acid can be used. Industrially, alkaline catalysts and sodium hydroxide are both very healthy. The saponification temperature is usually selected from the range of 10 to 50°C.

Regarding the modified PVA obtained in this way, it contains an alkyl sulfoxide group! (Degree of modification) is preferably 5 to 80 mol%, preferably 10 to 50 mol/l/%. If the amount is less than 5 mol %, the resulting cosmetic containing the cosmetic additive will not have sufficient wettability.

The degree of modification is preferably 10%/L'% or more.

On the other hand, if the degree of modification is too high, cosmetics containing the resulting cosmetic additives may have a sticky feel.
The content is preferably 50 mol% or less. Also, the degree of polymerization and saponification of modified PVA (vinyl alcohol units/(vinyl alcohol units 10 vinyl units μ units))
) K is not particularly limited, but from the viewpoint of film-forming properties of cosmetics, a degree of polymerization of 200 or more is preferable, and in the case of dispersed cosmetics such as emulsions, it is desirable to use partially saponified products with a low degree of saponification. . The degree of polymerization is usually 200 to 4,000, preferably 300 to 3,000. The degree of saponification is preferably 50 mo/L/% or more.

The effect of the cosmetic additive of the present invention is that the modified PVA of the present invention contains other ionic hydrophilic groups, hydrophobic groups, etc. in addition to units containing alkyl sulfoxide groups, vinyl alcohol units, and vinyl ester groups. There is no problem as long as it does not eliminate the It is preferable to coexist a small amount of a cationic group because it can impart adsorption properties to the skin and hair as an additive for cosmetics.

The additive for cosmetics made of modified PVA of the present invention is dissolved in water or a mixed solvent of water and alcohol, and then incorporated into cosmetics to provide an excellent feeling of use and finish.

The reason why such performance is exhibited has not been fully elucidated, but due to the action of Apki/L/Nurphoxyto groups in the modified PVA that constitutes the present invention, it is highly effective against hair and skin when cosmetics are used. It is presumed that this is the result of the synergistic effects of PVA's inherent film-forming properties and moisturizing effects, or its suspension and dispersion stability.

In the following examples, a cosmetic additive made of modified PVA containing an alkyl nulfoxyto group of the present invention was used as a shampoo,
We will also explain the cosmetics blended into the hand cream. In addition, in the following, parts mean parts by weight.

Polymerization degree = 1750 in a reaction vessel equipped with a stirrer and a temperature needle.
, Saponification degree 9B, 2Mo) 845 parts of a 5.2% aqueous solution of 7% PVA was added, and the temperature was raised to 60° C. while stirring. 1 for this
Add 400 parts of a 0% aqueous sodium hydroxide solution (the molar ratio of sodium hydroxide to the hydroxyl group of PVA is 1.0), and then add methyl vinyl/I/7. After adding 90 parts of /I/phoxite, the mixture was reacted at 60° C. for 5 hours with stirring. After the reaction vessel was externally cooled and the reaction solution was cooled to 25° C., the reaction solution was poured into a large amount of methanol, and the precipitated modified polymer was separated by furnace. The polymer was further thoroughly washed with methanol to remove the particles and unreacted methyl vinyl sulfoxide, and then dried at 70° C. for 5 hours.

The weight of the polymer observed was 55 parts, and the infrared absorption spectrum of this polymer showed absorption based on sulfoxide at 1010d, and secondary alcohol of 1100 ci'' I/C vinyl alcohol. Absorption based on p was observed, and it was found that this polymer was modified PVA modified with methyl vinyl sulfoxide.Furthermore, when the polymer was dissolved in heavy water and analyzed by proton nuclear magnetic resonance spectroscopy, it was found that vinyl alcohol -μ hydroxyl group decreases, absorption of methyl proton of methyl sulfoxide is observed at 2.5%, and proton signal of vinyl group of methyl vinyl sulfoxide is not observed. Therefore, the reaction is caused by the hydroxyl group of methyl vinyl 7 resulfoxide. It was found that modified PVA in which methyl sulfoxide groups were introduced through an addition reaction of groups was observed.The results of S elemental analysis revealed that the degree of modification of methyl sulfoxide units was 14.3 mol%. .

1000 parts of vinyl acetate and 20 parts of ethyl vinyl sulfoxide were placed in a flask equipped with a stirrer, thermometer, dropping funnel, and reflux condenser, and after purging the system with nitrogen, the internal temperature was raised to 60°C. .

A solution of 13 parts of 2.2'-azobisisobutyronitrile dissolved in 100 parts of methano-Iv was added to this system to initiate polymerization. During the polymerization time of 5 hours, 182 parts of a 25% methano-p solution of ethyl vinyl sulfoxide was added dropwise at a constant rate. The solid content concentration in the system at the time of termination of polymerization was 35%. Attach a gas introduction pipe and a vacuum distillation device to the flask, and blow methanol vapor into the heavy d reaction solution under reduced pressure.
After expelling the unpolymerized vinyl acetate monomer, a 33% methanol solution of the copolymer was obtained.

It was confirmed by nuclear magnetic resonance analysis that this copolymer contained 147 μ% of ethyl vinyl sulfoxide units and 86 mol% of vinyl acetate units. While stirring 100 parts of a methanol solution of this copolymer at 40°C, IN
10 parts by volume of a methanol solution of caustic soda was added thereto, mixed well, and left to stand. After 30 minutes, the solidified polymer was pulverized using a pulverizer, washed with methanol, and dried to obtain a polymer powder.

When this copolymer was dissolved in water and the viscosity was measured at 30°C, it was found to be 0.2 dl/f. Proton nuclear magnetic resonance spectroscopy analysis of a heavy aqueous solution of this copolymer revealed that the diethyl vinyl sulfoxide units were 14 mol %. The degree of saponification of the vinyl acetate unit was 97 mol%.

Example 1 and Comparative Examples 1 and 2 (Shampoo Composition) Using the modified PVA with an alkyl sulfoxyto group modification degree of 14.3 mo/l/% found in Synthesis Example-1 above, the following formulation was used. 100 parts of a shampoo aqueous composition for hair was obtained.

80.8 parts of purified water, 12 parts of sodium trioxyethylene lauryl ether sulfate, 3 parts of sodium lacryl sulfate, 2 parts of coconut oil fatty acid diethanolamide, 1.5 parts of the above alkyl resulfoxide group-modified PVA,
0.7 parts of fragrance. A sample solution obtained by diluting this shampoo aqueous composition 10 times with water was 200 mj! Soak a bunch of female hair (length 15(1) 5$F) for 2 minutes, massage and wash for 200 r.
Rinse 3 times with rLt water, lightly remove the liquid, and then
After air drying at 0°C and 60% ROH, the condition of the hair was observed. Table 1 shows the results of evaluating the shampooed condition and hair finish.

For comparison, the unmodified PVA was replaced with unmodified PVA with a saponification degree of 98% and a 4% aqueous solution having a viscosity of 28% at 20°C. Aqueous shampoo compositions were obtained in the same manner as in Example 1, except that 1.5 parts of Ocp's PVA (Comparative Example 1) or 2 parts of glycerin (Comparative Example 2) were used, and the same evaluations were carried out. The results are also shown in Table 1.

Table 1 Examples 2 and 3 (S/Young Composition) Same as Example 1 except that modified PVA with a different degree of modification synthesized according to Synthesis Example-1 was used in place of the modified PVA of Example 1. A shampoo composition was obtained in the same manner and evaluated. The evaluation results are also shown in Table 2.

Table 2 Example 4 and Comparative Example 3 (Hand cream composition) 13 parts of liquid paraffin, 1'2 parts of cetyl alcohol, 1 part of isopropyl valmitate, propylene glycol/I/
A hand cream composition was prepared by blending 4 parts of stearic acid-triethanolamine, 1 part of stearic acid-triethanolamine, and 2 parts of the modified PVA synthesized in Synthesis Example 2 (Example 4). For comparison, PVA used in Comparative Example 1 instead of modified PVA
A hand cream composition was prepared using the same formulation as in Example 4, except that the following was used (Comparative Example 3). As a result of applying and evaluating both hand cream compositions to the skin, Comparative Example 3 had a sticky feeling, whereas Example 4 had no sticky feeling and had an excellent feeling of use in terms of firmness, texture, and smoothness. I was able to get the finishing touch.

Patent applicant RiRashi Co., Ltd. Representative Patent Attorney Ken Mizune

Claims (4)

[Claims] (1) A cosmetic additive consisting of modified polyvinyl alcohol-μ containing an alkylsulfocarbon group in the molecule. (2) The additive for cosmetics according to claim 1, wherein the modified polyvinyl alcohol containing an alkyl sulfoxide group is a modified polyvinyl alcohol obtained by adding an alkyl vinyl sulfoxide to a hydroxyl group in the polyvinyl alcohol. (3) The additive for cosmetics according to claim 1, wherein the modified polyvinyl alcohol containing an alkyl sulfoxide group is a saponified copolymer of an alkyl vinyl sulfoxide and a vinyl ester. (4) The additive for cosmetics according to claim 1, wherein the content of units containing alkyl sulfoxide groups is 7 p%, 5 to 80 mol%, based on the total constituent units of the modified polyvinyl alcohol.