JP5091011B2 - Hairdresser - Google Patents

Description

  The present invention relates to a hair styling agent (hair styling agent), and more particularly to a hair styling agent (hair styling agent) suitable for aqueous hair styling agents such as hair sprays, hair mists, hair set lotions, and hair gels.

A hair styling agent (hair styling agent) is used for the purpose of imparting and holding a desired shape such as curl to the hair.
Such a hair styling agent usually has a polymer (set polymer) for maintaining a desired shape by forming a film on the hair surface, and an additive that is given for various purposes. It is a polymer composition in which a solvent, a base and the like are blended according to the dosage form.

  Examples of the set polymer include polyvinyl pyrrolidone polymer compounds, vinyl acetate ether polymer compounds, acidic polyvinyl acetate as disclosed in paragraphs 0030 to 0037 of JP-A-5-25025 (Patent Document 1). Polymeric compounds, acidic acrylic polymer compounds, amphoteric acrylic polymer compounds, basic acrylic polymer compounds, cellulose derivatives, chitin / chitosan derivatives, and the like are used. However, since these polymers alone have problems such as a film that is formed on the hair surface by coating and drying, a specific modified silicone may be used in combination for the purpose of imparting water repellency and lubricity. Has proposed.

  In JP-A-9-175959 (Patent Document 2), N-methacryloylethyl N, N-dimethylammonium / α-N-methylcarboxybetaine / alkyl methacrylate copolymer, vinylpyrrolidone / N, Proposing to use one or more polymers selected from N-dimethylaminoethyl methacrylic acid copolymer diethyl sulfate and vinyl pyrrolidone / vinyl acetate copolymer, and to use a specific seaweed extract together Yes. In the hair styling composition disclosed herein, when a large amount of the set polymer is blended, combing at the time of blowing deteriorates, hair becomes stiff when dried, and peeling of the formed film may occur. Although it happens, it was made to solve the problem that the setting power is insufficient when the amount of the set polymer is reduced. A specific seaweed extract is used as a plasticizer or modifier for the set polymer. By providing a smooth set film, the combing can be improved and moisture retention can be provided.

  Furthermore, in Japanese Patent Application Laid-Open No. 2003-95893 (Patent Document 3), a nonion that has been generally used as a set polymer in a viscous liquid or gel hairdressing agent that uses a crosslinked carboxyvinyl polymer as a gel-forming base. When a water-soluble resin (vinyl pyrrolidone polymer, vinyl pyrrolidone / vinyl acetate copolymer) is used, the film formed on the hair is hard and prone to flaking before moisture absorption, but sticks due to moisture absorption at high temperatures and humidity. When the betaine type acrylic resin that is an amphoteric resin is used, the predetermined shape imparted to the hair under high temperature and humidity is insufficient and the hardness is also low. It is explained that it is insufficient (paragraph numbers 0003 to 0005). In order to improve such drawbacks, it has been proposed to use primary amine-containing polyvinyl alcohol as a set polymer in viscous liquid and gel hairdressing agents that use cross-linked carboxyvinyl polymer as a gel-forming base. ing.

Japanese Patent Laid-Open No. 5-25025 Japanese Patent Laid-Open No. 9-175959 JP 2003-95893 A

  As described above, the set polymer alone cannot satisfy the desired set holding power, stickiness, and feel of combing at the same time, and is therefore supplemented by the combined polymer used together. In addition, depending on the combination with a solvent, a gel-forming base, or the like, there is a problem that the use of the set polymer is limited depending on the dosage form.

  For example, in the case of a spray-type hair styling agent, a volatile organic solvent has been conventionally used to increase the volatility after spraying. However, in recent years, from the viewpoint of environmental problems, a mixed solvent of a volatile organic solvent and water. The use of is required. Also in this respect, there is a problem that it is difficult to cope with a setting polymer that is easily sticky due to moisture absorption or a setting polymer that is poorly soluble in water and organic solvents.

  The present invention has been made in view of the above circumstances, and the object of the present invention is to have a hair set that has a good hair-setting retention force and is less sticky even under high humidity. It is to provide an agent.

The hairdressing agent of the present invention contains a polyvinyl alcohol-based resin containing a side chain 1,2-diol structural unit represented by the general formula (1), and the content of the side chain 1,2-diol structural unit is: It is characterized by being 1 to 12 mol% .

（（１）式中、Ｒ^１〜Ｒ^６ は水素原子を表し、Ｘは単結合を示す。）

((In ^1), R 1 to R ⁶ represents a water MotoHara child, X is shows a Tan'yui if.)

The content of the polyvinyl alcohol resin in the port Rimmer component is preferably at least 50 mass%.

  The aqueous hair spray of the present invention has a water content of 40% by mass or more obtained by dissolving the hair styling agent of the present invention.

  The hair styling agent of the present invention uses polyvinyl alcohol having a specific structure as a setting polymer, so that it has a set holding power and has a high moisturizing property, but is less sticky.

  The description of the constituent requirements described below is an example (representative example) of an embodiment of the present invention, and is not limited to these contents.

The hair styling agent of the present invention comprises a polyvinyl alcohol (hereinafter referred to as “side chain 1,2-diol-containing PVA”) resin having a side chain 1,2-diol unit represented by the general formula (1) as a polymer for setting. It is characterized by including.

In the general formula (1), R ^{1 to} R ⁶ each independently represent a hydrogen atom or an organic group. R ^{1 to} R ⁶ are preferably all hydrogen atoms, but may be organic groups as long as they do not significantly impair the resin characteristics. Although it does not specifically limit as this organic group, For example, C1-C4 alkyl groups, such as a methyl group, an ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, are preferable, You may have substituents, such as a halogen group, a hydroxyl group, an ester group, a carboxylic acid group, and a sulfonic acid group, as needed.

In the general formula (1), X is a single bond or a linking group, and is preferably a single bond from the viewpoints of set retention, non-stickiness, familiarity with hair, and the like. The bonding chain is not particularly limited, but other hydrocarbons such as alkylene, alkenylene, alkynylene, phenylene, naphthylene (these hydrocarbons may be substituted with halogen such as fluorine, chlorine, bromine, etc.) _{, -O -, - (CH 2} O) m -, - (OCH 2) m -, - (CH 2 O) mCH 2 -, - CO -, - COCO -, - CO (CH 2) mCO -, - _{CO (C 6 H 4) CO} -, - S -, - CS -, - SO -, - SO 2 -, - NR -, - CONR -, - NRCO -, - CSNR -, - NRCS -, - NRNR- _{, -HPO 4 -, - Si (} OR) 2 -, - OSi (OR) 2 -, - OSi (OR) 2 O -, - Ti (OR) 2 -, - OTi (OR) 2 -, - OTi ( _{OR) 2 O -, - Al} (OR) -, - OAl (OR) -, - OAl (O ) Although O- and the like (R is an optional substituent each independently, a hydrogen atom, an alkyl group are preferred, and m is a natural number) and the like. Among these, an alkylene group having 6 or less carbon atoms, particularly a methylene group, or —CH ₂ OCH ₂ — is preferable from the viewpoint of viscosity stability during production, heat resistance, and the like.

  The method for producing such side chain 1,2-diol-containing PVA is not particularly limited, but (i) a method of saponifying a copolymer of a vinyl ester monomer and a compound represented by the following general formula (2), (Ii) a method of saponifying and decarboxylating a copolymer of a vinyl ester monomer and a compound represented by the following general formula (3), (iii) a vinyl ester monomer and a compound represented by the following general formula (4) The copolymer is preferably produced by a method of saponifying and deketalizing the copolymer.

（２）（３）（４）式中、Ｒ^１〜Ｒ^６は、いずれも（１）式の場合と同様である。Ｒ^７及びＲ^８は、それぞれ独立して水素またはＲ^９−ＣＯ−（式中、Ｒ^９は、アルキル基である）。Ｒ^１０及びＲ^１１は、それぞれ独立して水素原子又は有機基である。

(2) In the formulas (3) and (4), R ^{1 to} R ⁶ are the same as those in the formula (1). R ⁷ and R ⁸ are each independently hydrogen or R ⁹ —CO— (wherein R ⁹ is an alkyl group). R ¹⁰ and R ¹¹ are each independently a hydrogen atom or an organic group.

  As the methods (i), (ii) and (iii), for example, the method described in JP-A-2006-95825 can be employed.

Among them, the method in terms of excellent in copolymerization reactivity and industrial handling (i) are preferred, ^R 1 to R ⁶ are hydrogen atoms, X is a single bond, ^{R 7} and ^{R 8} are ^R 9 -CO 3,4-diasiloxy-1-butene in which R ⁹ is an alkyl group is preferred, and among these, 3,4-diacetoxy-1-butene in which R ⁹ is a methyl group is particularly preferred.

  It should be noted that when vinyl acetate is used as the vinyl ester monomer and this is copolymerized with 3,4-diacetoxy-1-butene, the reactivity ratio of each monomer is r (vinyl acetate) = 0.710, r ( 3,4-diacetoxy-1butene) = 0.701, which is r (vinyl acetate) in the case of vinyl ethylene carbonate, which is a compound represented by the general formula (3) used in the method (ii) = Compared to 0.85 and r (vinyl ethylene carbonate) = 5.4, 3,4-diacetoxy-1-butene is excellent in copolymerization reactivity with vinyl acetate.

  Examples of the vinyl ester monomers include vinyl formate, vinyl acetate, vinyl propionate, vinyl valelate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl benzoate, versatic. Vinyl acid, vinyl trifluoroacetate and the like can be mentioned, and vinyl acetate is preferably used from the economical viewpoint.

  In addition to the above-mentioned monomers (vinyl ester monomers, compounds represented by the general formulas (2), (3), and (4)), the effects of the present invention such as set holding power, water solubility and moisture retention are not impaired. If present, α-olefins such as ethylene and propylene as copolymerization components; hydroxy group-containing α-olefins such as 3-buten-1-ol, 4-penten-1-ol, and 5-hexene-1,2-diol Derivatives thereof such as itaconic acid, maleic acid, acrylic acid, undecylenic acid or the like, or salts thereof, mono- or dialkyl esters, nitriles such as acrylonitrile, amides such as methacrylamide, diacetone acrylamide, Olefin sulfonic acids such as ethylene sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, and AMPS Alternatively, a compound such as a salt thereof may be copolymerized.

The side chain 1,2-diol-containing PVA resin as described above is superior in set holding power even under high humidity and hygroscopic compared to a set polymer conventionally used in the field of hair styling agents. Despite being, there is a feature that there is little stickiness. In particular, polyacrylic acid-based resins and polyvinylpyrrolidone-based resins have had to be reduced in terms of increase in stickiness when the amount is increased in order to increase the set holding power. , 2-diol-containing PVA has a large set holding power and little stickiness, so that it can satisfy both requirements regarding set holding power and stickiness as a set polymer. Furthermore, even when compared with other PVA-based resins that do not contain a side chain 1,2-diol bond, the moisture retention is high. In this regard, conventional PVA has been inferior in moisturizing power compared to acrylic resin and polyvinylpyrrolidone resin, so it has been inevitable to use a moisturizing agent in terms of reducing damage to hair. In combination with a moisturizer, the stickiness increased, and it was difficult to satisfy conflicting requirements such as moisturizing and smoothness. However, side chain 1,2-diol-containing PVA resins are superior to conventional PVA resins in terms of moisturizing power, ensuring moisturizing without the use of moisturizing agents, and making the hair smoother. A feeling can be secured.
Further, the side chain 1,2-diol-containing PVA resin is less crystalline than a normal PVA resin and is easy to set because of less shrinkage during film formation, and more hydrophilic than a normal PVA resin. Because of its high nature, it is well-familiar with hair and provides a smooth finish.

  The content of the side chain 1,2-diol unit in the side chain 1,2-diol-containing PVA resin used in the present invention is usually preferably 1 to 12 mol%, more preferably 2 to 10 mol%, Preferably it is 3-8 mol%. If the content of the side chain 1,2-diol unit is too high, the set holding power tends to be reduced, and if it is too low, the moisture retention is reduced and the effect of reducing damage to hair tends to be poor.

In addition, the content of the side chain 1,2-diol unit in the PVA resin is determined from a ¹ H-NMR spectrum (solvent: DMSO-d6, internal standard: tetramethylsilane) of a completely saponified PVA. Specifically, it can be calculated from the peak area derived from the hydroxyl proton, methine proton, and methylene proton in the 1,2-diol unit, the methylene proton in the main chain, the proton in the hydroxyl group linked to the main chain, etc. Good.

  The polymerization degree of the side chain 1,2-diol-containing PVA resin used in the present invention is preferably 300 to 3000, more preferably 500 to 2500, and still more preferably 800 to 2000. If the degree of polymerization is too high, the hairdressing agent will have a high viscosity, making it difficult to use, or the film will become hard and stiff, and flaking will tend to increase. It is in.

  The saponification degree of the side chain 1,2-diol-containing PVA resin used in the present invention is usually preferably 95 mol% or more, more preferably 97 mol% or more, and further preferably 99 mol% or more. When it is too low, the affinity with the hair surface is lowered, and the set holding power tends to be lowered.

[Other resins]
The hair styling agent of the present invention has been used as a polymer component other than a side chain 1,2-diol-containing PVA resin and a PVA resin not containing a side chain 1,2-diol or a conventional set polymer. A resin may be contained. The blending ratio is appropriately determined depending on the dosage form, required physical properties, etc., but the side chain 1,2-diol-containing PVA is not damaged so as not to impair the characteristics of the side chain 1,2-diol-containing PVA resin as the set polymer. The content of the resin is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably 90% by mass or more (both solid content ratio).

  Other PVA resins include unmodified PVA, partially saponified PVA, carboxylic acid modified PVA, undecylenic acid modified PVA, acetal modified PVA, amide modified PVA, vinyl ether modified PVA, thiol modified PVA, silanol modified PVA, cation modified PVA. , Α-olefin modified PVA such as sulfonic acid modified PVA, ethylene modified PVA, vinyl ester modified PVA, amine modified PVA, oxyalkylene modified PVA, acetoacetate group containing PVA, diacetone acrylamide modified PVA, terminal thiol group modified PVA, Examples thereof include terminal alkyl group-modified PVA.

  Resins other than PVA resins include poly (meth) acrylic such as polyacrylic acid ester, acrylic acid ester / methacrylic acid ester copolymer, and hydroxypropyl acrylate / butylaminoethyl methacrylate / octylamide acrylate copolymer. Acid-based polymers; polyvinyl pyrrolidone polymers such as polyvinyl pyrrolidone and polyvinyl pyrrolidone / vinyl acetate copolymer; vinyl methyl ether / butyl maleate copolymer, water-soluble nylon, HPMC, CMC and the like.

[Other ingredients]
The hair styling agent of the present invention uses a side chain 1,2-diol-containing PVA-based resin as a polymer for setting, as long as the characteristics of the side chain 1,2-diol-containing PVA-based resin are not impaired. Nonionic, anionic, cationic or amphoteric surfactants, various oils, alcohols, dimethylpolysiloxane, amino-modified silicone and other silicone derivatives, thickeners, moisturizers, plasticizers, plant extracts, etc. Various additives such as medicinal ingredients, ultraviolet absorbers, antioxidants, vitamins, preservatives, neutralizers, pH adjusters, pigments, and fragrances may be appropriately blended.

  Examples of the anionic surfactant include triethanolamine lauryl sulfate, sodium cetyl sulfate, sodium lauryl sulfate, N-stearoyl-L-glutamate sodium, N-myristoyl-L-glutamate sodium, N-lauroyl-L-glutamate sodium, lauroyl Sodium sarcosine, sodium lauroylmethyl taurate, polyoxyethylene lauryl ether sulfate triethanolamine, sodium polyoxyethylene lauryl ether sulfate, sodium polyoxyethylene alkylphenyl ether phosphate, polyoxyethylene cetyl ether phosphate, polyoxyethylene cetyl ether phosphate Sodium phosphate, polyoxyethylene lauryl ether phosphate, polyoxyethylene lauryl ether phosphate sodium Hitoshigage be.

  Examples of the amphoteric surfactant include 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, lauryldimethylaminoacetic acid betaine, N, N-dimethyl-N-alkyl-N-carboxymethylammonium betaine, N , N-dialkylaminoalkylene ammonium betaine, N, N, N-trialkyl-N-sulfoalkylene ammonium betaine, N, N-dialkyl-N, N-bis (polyoxyethylene sulfate) ammonium betaine, and the like.

  Examples of the cationic surfactant include cetyltrimethylammonium chloride, distearyldimethylammonium chloride, stearyldimethylbenzylammonium chloride, benzalkonium chloride, stearyltrimethylammonium chloride, lauryltrimethylammonium chloride, and cetyltrimethylammonium bromide.

  Examples of the nonionic surfactant include polyoxyethylene octylphenyl ether, polyoxyethylene glycol monooleate, diethanolamide stearate, polyoxyethylene hydrogenated castor oil, sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, hexastearin Acid polyoxyethylene sorbit, sucrose fatty acid ester, lipophilic glyceryl monooleate, monostearic acid polyoxyethylene glycerin coconut oil fatty acid diethanolamide, polyoxyethylene cetyl ether, polyethylene glycol monolaurate, sorbitan monooleate, monostearate Polyoxyethylene sorbitan acid, polyoxyethylene sorbitol tetraoleate, polyoxyethylene glyceryl monostearate Etc. The.

  The content of these surfactants in the hairdressing agent is usually preferably about 0.01 to 5% by mass. As the oil agent, silicon derivatives such as dimethylpolysiloxane and methylphenylsiloxane, castor oil, coconut oil, liquid lanolin, beeswax, squalane, liquid paraffin, oleyl alcohol, lauryl alcohol, cetanol, stearyl alcohol, isopropyl myristate, cetyl lactate, Examples include diisopropyl adipate, hexyl decyl dimethyloctanoate, decyl oleate, hexyl laurate, butyl stearate, isopropyl palmitate and the like. The content of these oil agents in the hair styling agent is usually preferably about 0.01 to 45% by mass.

  As alcohols, polyhydric alcohols such as glycerin, 1,3-butylene glycol, propylene glycol, polyethylene glycol, mannitol, sorbitol, dipropylene glycol, and monohydric alcohols such as ethanol, isopropanol, cetanol, and lauryl alcohol can be used. As the neutralizing agent or pH adjusting agent, hydrochloric acid, phosphoric acid, succinic acid, citric acid, diisopropanolamine, triethanolamine, acids such as ammonia, potassium hydroxide, sodium hydroxide, and alkalis are used.

(Dosage form)
The hair styling agent of the present invention can be used in various dosage forms such as hair foam, hair mist, hair gel, set lotion and the like. Depending on the dosage form, a solvent, a gel forming agent, a propellant and the like are appropriately blended. In particular, the side chain 1,2-diol-containing PVA resin used in the present invention is excellent in water solubility and also dissolves in an alcohol solvent. Therefore, water or a water / alcohol mixed solvent is used as the solvent. In addition, it is possible to provide a hair styling agent having an increased content of the set polymer.

  Therefore, it is possible to use a water / alcohol mixed solvent instead of only a volatile organic solvent in aerosols and pump-type spray-type hair styling agents. An aqueous hair spray that reduces the amount used can be provided.

  Preferred alcohols include low boiling alcohols such as ethanol and propanol. In the case of an aqueous hair spray using a water / alcohol mixed solvent, the content of water in the total amount is preferably 40% by mass or more.

  In the case of aerosol spray, it is preferable to contain a propellant. Propellants include alkanes such as propane, n-butane, i-butane, and pentane, and liquefied petroleum gases such as liquefied petroleum gas, dimethyl ether, and mixtures thereof, compressed gases such as carbon dioxide, nitrogen, nitrous oxide, and compressed air. These may be used alone or in combination of two or more. Of these, dimethyl ether or a mixed gas of this and liquefied petroleum gas is preferably used. In particular, when an aqueous spray having a water content of 25% by mass or more, preferably 40% by mass or more is used, it is preferable to use dimethyl ether having good solubility in water. Among them, it is preferable to use ethanol as the organic solvent and dimethyl ether as the propellant because of its good solubility in water. In this case, it is preferable to use 15-60 mass% of water / ethanol mixed solvent and 20-40 mass% of dimethyl ether. The amount of the propellant used is usually 10 to 60% by mass in all components, and in the case of an aqueous hair spray having a water content of 40% by mass or more, preferably 10 to 50% by mass, more preferably 20%. -40 mass%. If the amount of the propellant is less than 10% by mass, it does not become a mist at the time of injection, but becomes a rod-like injection, and a fine mist spray may not be obtained. It is not preferable because the stability may be insufficient, the spray pressure may be too high, the mist may be scattered around, or the hair style may be broken by the force of spraying.

In addition, when the hair styling agent and aqueous spray of the present invention are used in the form of an aerosol product filled in a metal container, in order to ensure stability during storage, in addition to the above components, corrosion prevention For example, it is preferable to add 0.001-5 mass% of an agent with respect to all the components.
Examples of corrosion inhibitors include monoethanolamine borate, monoisopropanolamine borate, inorganic hydroxides such as sodium hydroxide, ammonium hydroxide, potassium hydroxide, nitromethane, dimethyloxazolidone, 2-dimethylamino-2-methyl-1- Examples include propanol and aminomethylpropanol.

  Further, the side chain 1,2-diol-containing PVA resin of the present invention includes shampoos, rinses, hair creams, hair treatment lotions, styling agents, coloring agents, hair manicures, colored rinses, split ends in addition to hair styling agents. It can also be used in various hair care agents such as a coating agent, sunscreen, eyeliner, mascara, bathing agent, solid foundation binder, and the like.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the description of the examples unless it exceeds the gist.
In the examples, “part” means mass basis unless otherwise specified.

[Evaluation measurement method]
(1) Equilibrium moisture absorption About 5 g of a 5% by mass aqueous solution of the polymer for setting was weighed into an aluminum cup having a bottom diameter of 5.3 cm and dried at 50 ° C. for 5 hours. This was allowed to stand in a constant temperature and humidity chamber of 30 ° C. and 90% RH until the mass was constant, and after measuring its mass (W), it was dried at 105 ° C. for 3 hours to obtain an absolutely dry mass (W ₀ ). The equilibrium moisture absorption rate was obtained by the following equation.
Equilibrium moisture absorption (mass%) = {(W−W ₀ ) / W ₀ } × 100

(2) Set holding force A 3% by weight aqueous solution of a set polymer is uniformly applied to a hair bundle having a length of 20 cm and a weight of 1.2 g, wound on a rod having a diameter of 1 cm, and dried at 50 ° C. for 1 hour. The rod was removed from the curled hair. This was suspended perpendicularly to a constant temperature and humidity machine at 30 ° C. and 90% RH, and after 3 hours, this was taken out, and the curl retention (%) was determined from the length of the hair bundle before and after standing by the following formula.
Curl retention (%) = {(L−L ₃ ) / (L−L ₀ )} × 100
L: Length of hair bundle (cm)
L ₀ : length of hair bundle (cm) immediately after removal from the rod
L ₃ : Length of hair bundle (cm) after being left for 3 hours in a thermo-hygrostat

(3) Stickiness The curled hair obtained above was left in a constant temperature and humidity chamber at 30 ° C. and 90% RH for 24 hours, and the stickiness feeling when touched with a finger was panel-evaluated according to the following criteria. The evaluation results were averaged.
5 points: No sticky feeling 3 points: A little sticky feeling 1 point: Large sticky feeling

[Evaluation of set polymer]
Example 1:
In a reaction vessel equipped with a reflux condenser, a dropping funnel and a stirrer, 82.8 parts of vinyl acetate, 9.9 parts of methanol, 7.3 parts of 3,4-diacetoxy-1-butene (4.4 mol% to charged acetic acid) Vinyl) was charged, 0.032 mol% of azobisisobutyronitrile (vs. vinyl acetate charged) was added, and the temperature was raised under a nitrogen stream while stirring to initiate polymerization. As the polymerization proceeds, 1.9 parts of 3,4-diacetoxy-1-butene is added dropwise using the conditions of the HANNA method. When the polymerization rate reaches 72.5%, a predetermined amount of m-dinitrobenzene is added. Then, the polymerization was completed, and subsequently, unreacted vinyl acetate monomer was removed from the system by a method of blowing methanol vapor to obtain a methanol solution of the copolymer.
Next, the methanol solution was diluted with methanol, adjusted to a concentration of 44%, charged into a kneader, and while maintaining the solution temperature at 35 ° C., a 2% methanol solution of sodium hydroxide was added to the vinyl acetate structural unit in the copolymer and Saponification was carried out for 4 hours by adding 12.5 mmol to 1 mol of the total amount of 3,4-diacetoxy-1-butene structural units. When saponification progresses as saponification progresses and forms particles, it is separated by solid-liquid separation, washed well with methanol, and dried in a hot air dryer at 70 ° C. for 15 hours to achieve the target side. A chain 1,2-diol-containing PVA resin was prepared.

The saponification degree of the obtained side chain 1,2-diol-containing PVA resin was analyzed by the alkali consumption required for hydrolysis of residual vinyl acetate and 3,4-diacetoxy-1-butene. Mol%. The average degree of polymerization was 1300 when analyzed according to JIS K 6726. Further, the content of the 1,2-diol structural unit represented by the structural formula (1) was 6 mol% when calculated by measurement with ¹ H-NMR (internal standard substance; tetramethylsilane). .

  The obtained side chain 1,2-diol-containing PVA resin was used as a set polymer, and the equilibrium moisture absorption rate, set holding power, and stickiness were evaluated based on the above evaluation methods. The results are shown in Table 1.

Comparative Example 1:
In place of the side chain 1,2-diol-containing PVA resin, unmodified PVA (degree of polymerization: 1300, degree of saponification: 99 mol%) was used in the same manner as in Example 1, and the equilibrium moisture absorption rate and set Holding power and stickiness were evaluated. The results are shown in Table 1.

Comparative Example 2:
About the sample obtained by mix | blending glycerol (Nippon Yushi Co., Ltd. "RG") as a moisturizer with the unmodified PVA prepared in the comparative example 1 in the ratio of 5 mass parts per 90 parts of resin solid content, the said evaluation The equilibrium moisture absorption was measured based on the method.
The surface of the sample film after measuring the equilibrium moisture absorption was slimy.

Comparative Example 3:
Instead of the side chain 1,2-diol-containing PVA resin, polyacrylic acid (“Purasize L-6330” manufactured by Mutual Chemical Industry Co., Ltd., resin content 30% by mass, water / ethanol mixed solution) is used. Samples having the same content as that of Example 1 were prepared, and the equilibrium moisture absorption rate, set holding power, and stickiness were evaluated based on the above evaluation methods. The results are shown in Table 1.

Comparative Example 4:
A sample was prepared in the same manner as in Example 1 except that polyvinylpyrrolidone (“PVP K-30” manufactured by ISP Japan Co., Ltd.) was used instead of the side chain 1,2-diol-containing PVA-based resin. Based on this, the equilibrium moisture absorption rate, set holding power, and stickiness were evaluated. The results are shown in Table 1.

As can be seen from Table 1, as a set polymer, polyvinyl pyrrolidone has a high equilibrium moisture absorption, but the set retention and stickiness are very inferior, and polyacrylic acid is superior in set retention compared to polyvinyl pyrrolidone. There was little stickiness.
On the other hand, in Example 1 using the side chain 1,2-diol-containing PVA-based resin, while having an equilibrium moisture absorption rate similar to that of polyacrylic acid, the polyacrylic acid can be used both in terms of set holding power and stickiness. It was better than acid.
When the side chain 1,2-diol-containing PVA resin and unmodified PVA were compared, the evaluation results were about the same in terms of set holding power and stickiness. -The diol-containing PVA resin was superior. Although it is possible to increase the equilibrium moisture absorption rate by using the unmodified PVA and the humectant in combination, the stickiness becomes severe and practically troublesome.

  Therefore, the side chain 1,2-diol-containing PVA-based resin can exhibit a superior set holding force even under high humidity while ensuring a smoother feeling than the conventional setting polymer, and also has a moisturizing power. As a result, there is little damage to the hair.

  Since the hair styling agent of the present invention can satisfy both requirements regarding the set holding power and stickiness with the set polymer alone, it is possible to select other base materials to be used in a wide range, and various agents Easy to apply to shape.

Claims (3)

The hair-styling agent characterized by containing the polyvinyl alcohol-type resin whose content rate of the side chain 1, 2-diol structural unit shown by General formula (1) is 1-12 mol%.

(In the formula (1), R ^{1 to} R ⁶ represent a hydrogen atom, and X represents a single bond.) The hairdressing agent according to claim 1, wherein the content of the polyvinyl alcohol-based resin in the polymer component is 50% by mass or more. An aqueous hair spray having a water content of 40% by mass or more obtained by dissolving the hairdressing agent according to claim 1 or 2 .