WO2015133629A1 - Acrylic resin emulsion for hairdressing agent, hairdressing agent containing acrylic resin emulsion for hairdressing agent, and hairdressing method - Google Patents

Abstract

The present invention is an acrylic resin emulsion for a hairdressing agent. The acrylic resin emulsion is suitable for producing a hairdressing agent that has excellent and balanced washability and styling performance (hairdressing performance, hair-redressing performance, tactile properties), is obtained by emulsion polymerizing a monomer composition [I] and a monomer composition [II], and is characterized by satisfying conditions (i), (ii), and (iii). (i) At least one of the monomer composition [I] and the monomer composition [II] includes a methacrylate monomer. (ii) The glass transition temperature (Tg2) as found by the Fox equation for a polymer that is polymerized using the monomer composition [II] is at least 30℃ higher than the glass transition temperature (Tg1) as found by the Fox equation for a polymer that is polymerized using the monomer composition [I]. (iii) The mixing proportions (weight ratio) of the monomer composition [I] and the monomer composition [II] are [I]:[II]=50:50-99:1.

Description

Acrylic resin emulsion for hair styling agent, hair styling agent containing the same, and hair styling method

TECHNICAL FIELD The present invention relates to an acrylic resin emulsion useful as a hair styling agent (hair styling agent). More specifically, the present invention is excellent in water-solubility and / or redispersibility in water. The present invention relates to an acrylic resin emulsion excellent in balance with performance.

There are various types of hairdressing agents such as liquid, gel, foam, mist, cream and wax.
Usually, hairdressing agents are mainly composed of a polymer (setting polymer) for maintaining a desired shape by forming a film on the hair surface, and depending on additives and dosage forms applied for various purposes. A polymer composition containing a solvent, a base, and the like. In recent years, hair styling agents can be freely arranged at the time of hair styling, and hair creams and hair waxes, which are emulsifiers using oil and water, have become mainstream as dosage forms that can be easily modified after styling. Yes.

In addition, hairdressing agents are required to have performance in styling (conditioning hair) such as the ability to give the hair a desired shape and hold it for a long time, excellent appearance performance, and excellent tactile feel. In addition, the convenience of washing and removing the hairdressing agent from the hair after use is also required as a performance, and various hairdressing agents have been developed.

For example, Patent Document 1 describes an aqueous hair styling agent using a polyvinyl alcohol-based resin having a specific structure as a main component of a polymer component as a main ingredient. Patent Document 2 describes beeswax and an interface. A hair cosmetic is described in which polyvinyl alcohol is blended as a blending agent in an emulsion composition comprising an active agent and water.

Japanese Unexamined Patent Publication No. 2009-286724 Japanese Unexamined Patent Publication No. 2011-148721

The hair styling agent of Patent Document 1 has the performance that the polyvinyl alcohol-based resin having a specific structure has a good curl holding power under high humidity conditions, has less stickiness, has a moisturizing power, and has little damage to hair. In addition, the hairdressing agent of Patent Document 2 described above improves aesthetics at the time of use by blending a polyvinyl alcohol resin in the emulsion composition, and does not impart unnatural shine to the hair after application. It has performance.
However, the hair styling agent described in Patent Document 1 has room for improvement in terms of inadequate goodness as a hand comb (finger), comb, brush, or the like, and in terms of re-styling when hair is broken once. It remained. Further, the hair styling agent described in Patent Document 2 has a large stickiness, and further improvement in the feeling of use is required.

Furthermore, recent hair styling agents are required to have good hair styling power and re-hair styling performance, and further have a hair styling holding power capable of holding a hair style once hair styled for a long time. On the other hand, the hair styling agent with good hair styling power, as described above, is often poorly washed off because it contains many oil components such as wax, so it can be rubbed strongly with shampoo or twice. It is necessary to do so, which causes rough scalp and dry trouble. There is also concern about scalp troubles such as dandruff, itching and hair loss due to oil components remaining if washing is insufficient.
Therefore, recent hair styling agents are desired to have both good styling performance (hair styling) and good washability.

Therefore, in view of such problems, the present invention provides styling performance (hair styling performance (setting power), re-hair styling performance (re-setting power, re-setting holding power), tactile sensation and performance to be washed with water or lukewarm water. It is an object of the present invention to provide an acrylic resin emulsion for a hair styling agent that is effectively used in a hair styling that is excellent in balance.

However, as a result of intensive studies in view of such circumstances, the inventors of the present invention are acrylic resin emulsions obtained by emulsion polymerization of at least two monomer compositions, at least one of which is a (meth) acrylate monomer. The difference between the glass transition temperatures of the two polymers when each of the monomer compositions is polymerized is 30 ° C. or more, and the monomer composition having the higher glass transition temperature is the monomer having the lower glass transition temperature. A hair styling agent containing an acrylic resin emulsion obtained by emulsion polymerization in an amount less than the composition has styling performance (hair styling performance (setting power), re-hair styling performance (re-setting power), tactile sensation) and cleaning performance. The present invention has been completed by finding that it is excellent in balance.

That is, the gist of the present invention is as follows.
[1] An acrylic resin emulsion for hairdressing agent obtained by emulsion polymerization of the monomer composition [I] and the monomer composition [II],
An acrylic resin emulsion for a hair conditioner, wherein the monomer composition [I] and the monomer composition [II] satisfy the following conditions (i) to (iii):
(I) At least one of the monomer composition [I] and the monomer composition [II] contains a (meth) acrylate monomer.
(Ii) The glass transition temperature (Tg2) determined by the Fox formula of the polymer polymerized using the monomer composition [II] is determined by the Fox formula of the polymer polymerized using the monomer composition [I]. 30 ° C. or more higher than the glass transition temperature (Tg1).
(Iii) The blending ratio (weight ratio) of the monomer composition [I] and the monomer composition [II] is monomer composition [I]: monomer composition [II] = 50: 50 to 99: 1.
[2] The acrylic resin emulsion for hairdressing agent according to the above [1], wherein the glass transition temperature (Tg1) is 0 ° C. or lower and the glass transition temperature (Tg2) is 30 ° C. or higher.
[3] The acrylic resin emulsion for hairdressing agent according to [1] or [2], wherein the acrylic resin particles in the acrylic resin emulsion are dispersed and stabilized by a polyvinyl alcohol resin.
[4] The acrylic resin emulsion for hairdressing agents according to [3], wherein the polyvinyl alcohol-based resin contains a side chain 1,2-diol structural unit represented by the following formula (1).

(In formula (1), R ¹ to R ⁶ each independently represents a hydrogen atom or an organic group, and X represents a single bond or a bond chain.)

[5] Using only the monomer composition [I] and the monomer composition [II], the monomer composition [I] is first subjected to emulsion polymerization, and then the monomer composition [II] is subjected to emulsion polymerization. The acrylic resin emulsion for hairdressing agents according to any one of the above [1] to [4], wherein
[6] A hair styling agent comprising the acrylic resin emulsion for hair styling according to any one of [1] to [5].
[7] A hair styling method including the following step (A) and step (B).
(A) an effective hair amount, a step of applying an acrylic resin emulsion for hairdressing agent obtained by emulsion polymerization of the monomer composition [I] and the monomer composition [II] to the hair;
(B) A step of adjusting the hair into a desired shape before, simultaneously with and after the step (A).
However, the monomer composition [I] and the monomer composition [II] satisfy the following conditions (i) to (iii).
(I) At least one of the monomer composition [I] and the monomer composition [II] contains a (meth) acrylate monomer.
(Ii) The glass transition temperature (Tg2) determined by the Fox formula of the polymer polymerized using the monomer composition [II] is determined by the Fox formula of the polymer polymerized using the monomer composition [I]. 30 ° C. or more higher than the glass transition temperature (Tg1).
(Iii) The blending ratio (weight ratio) of the monomer composition [I] and the monomer composition [II] is monomer composition [I]: monomer composition [II] = 50: 50 to 99: 1.

The acrylic resin emulsion for hairdressing agent of the present invention is excellent in water solubility and / or redispersibility in water, and the hairdressing agent containing such an acrylic resin emulsion for hairdressing agent is excellent in performance to be washed, It also has an excellent effect in balance with styling performance.

The present invention will be described in detail below, but these show examples of desirable embodiments.
In the present invention, (meth) acryl means acryl or methacryl, (meth) acryloyl means acryloyl or methacryloyl, and (meth) acrylate means acrylate or methacrylate. It is a resin obtained by polymerizing a monomer component containing at least one (meth) acrylic monomer.

<Acrylic resin emulsion for hairdressing agent>
The acrylic resin emulsion for hairdressing agent of the present invention is an acrylic resin emulsion obtained by emulsion polymerization of the monomer composition [I] and the monomer composition [II], and the monomer composition [I] and the monomer composition. The product [II] satisfies the following conditions (i) to (iii).
(I) At least one of the monomer composition [I] and the monomer composition [II] contains a (meth) acrylate monomer.
(Ii) Glass whose glass transition temperature (Tg2) determined by the Fox formula of the polymer polymerized using the monomer composition [II] is determined by the Fox formula of the polymer polymerized using the monomer composition [I] 30 ° C. or higher than the transition temperature (Tg1).
(Iii) The blending ratio (weight ratio) of the monomer composition [I] and the monomer composition [II] is monomer composition [I]: monomer composition [II] = 50: 50 to 99: 1.

The acrylic resin emulsion for hairdressing agent may be an acrylic resin emulsion obtained by emulsion polymerization of only the monomer composition [I] and the monomer composition [II] in two stages, or other monomer compositions. It may be an acrylic resin emulsion obtained by emulsion polymerization in three or more stages. When emulsion polymerization is performed in three or more stages, the polymerization may be performed before, after or during the emulsion polymerization of the monomer composition [I] and the monomer composition [II].

Among these, an acrylic resin emulsion obtained by emulsion polymerization of only the monomer composition [I] and the monomer composition [II] as monomer components in two stages is preferable because the operation procedure is simple. Further, an acrylic resin emulsion obtained by emulsion polymerization of only the monomer composition [I] and the monomer composition [II] in two steps in this order is particularly preferable because it can be stably produced. In addition to the monomer component, <other components> described later can be used as appropriate.

In the present invention, it is necessary that at least one of the monomer composition [I] and the monomer composition [II] includes a (meth) acrylate monomer, and preferably the monomer composition [I] and the monomer composition. It is preferable that both of [II] contain a (meth) acrylate-based monomer because unreacted products tend to decrease and the amount of residual monomer is reduced, that is, the safety is increased and the odor is low.

In the present invention, the glass transition temperature (Tg2) determined by the Fox formula of the polymer polymerized using the monomer composition [II] is determined by the Fox formula of the polymer polymerized using the monomer composition [I]. It is necessary that the monomer composition [I] and the monomer composition [II] are adjusted to be higher by 30 ° C. or more than the glass transition temperature (Tg1), and the glass transition temperature (Tg1) and the glass transition temperature ( The difference from Tg2) is preferably 40 ° C. or higher, particularly preferably 50 ° C. or higher, more preferably 60 ° C. or higher, particularly preferably 90 ° C. or higher.
If the difference between Tg2 and Tg1 is too small, the washability tends to decrease, which is not preferable. The upper limit of the difference between Tg2 and Tg1 is usually 300 ° C., preferably 200 ° C.

The above Tg1 and Tg2 are calculated based on the glass transition temperature of each homopolymer by the following Fox equation. In addition, the glass transition temperature of the homopolymer in the following Fox formula is determined by the monomer type of the homopolymer.
That is, the glass transition temperatures (Tga, Tgb,... Tgn) of the homopolymers can use values described in “Polymer Handbook 3rd Edition, John Wiley & Sons, Inc, 1989”, respectively. As for the homopolymer of the monomer type that is not present, a homopolymer having an average molecular weight of 10,000 or more and less than 1,000,000 can be polymerized and confirmed by differential scanning calorimetry (DSC) or the like. In addition, the said average molecular weight is a weight average molecular weight in polystyrene conversion by gel permeation chromatography (GPC).

From the above, the glass transition temperature (Tg1 and Tg2) of the polymer can be determined from the monomer species and the weight fraction.
In some cases, the glass transition temperature (Tg) of the homopolymer may not be measured for some monomers. In this case, when the monomer content is about 5% by weight or less, there is little influence on the polymer physical properties. Therefore, the monomer is not considered as a constituent in the Fox formula.

The Tg1 is preferably 0 ° C. or less, particularly preferably −20 ° C. or less, and further preferably −30 ° C. or less.
If Tg1 is too high, the acrylic resin particles in the acrylic resin emulsion become too hard and sufficient tackiness cannot be obtained, and the re-styling property tends to decrease.
The lower limit of Tg1 is usually −80 ° C., preferably −75 ° C.

The Tg2 is preferably 30 ° C. or higher, particularly preferably 40 ° C. or higher, more preferably 50 ° C. or higher, and particularly preferably 60 ° C. or higher.
When Tg2 is too low, the acrylic resin particles in the resulting acrylic resin emulsion are too soft, and there is a tendency that continuous hair styling performance cannot be obtained. When Tg2 is high, the cohesive strength of the acrylic resin obtained increases locally, and thus there is a tendency for stickiness to appear and good re-hairing properties.
The upper limit of Tg2 is usually 230 ° C, preferably 150 ° C.

The blending ratio (weight ratio) of the monomer composition [I] and the monomer composition [II] in the present invention is such that the monomer composition [I]: monomer composition [II] = 50: 50 to 99: 1. Necessary, preferably 60:40 to 98: 2, particularly preferably 65:35 to 97: 3, and more preferably 70:30 to 95: 5.
If the amount of the monomer composition [II] is too large relative to the monomer composition [I], the polymerization stability tends to decrease and the hair styling property tends to be insufficient, and if it is too small, the balance between the hair styling property and the washability decreases. Tend to.

<Monomer composition [I]>
The monomer composition [I] will be specifically described.
Examples of the monomer composition [I] include (meth) acrylic monomers (I-1) and functional group-containing monomers (I-2). The monomer composition [I] may be composed of only one or two or more (meth) acrylic monomers (I-1) or only one or two or more functional group-containing monomers (I-2). In addition, one or more kinds of (meth) acrylic monomers (I-1) and one or more kinds of functional group-containing monomers (I-2) may be contained. Of these, the (meth) acrylic monomer (I-1) is preferably the main component.

Examples of the (meth) acrylic monomer (I-1) include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, and t-butyl (meth) ) Acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, lauryl (meth) acrylate, octyl (meth) acrylate, stearyl (meth) acrylate, and other aliphatic (meth) acrylate monomers; phenoxy (meth) Aromatic (meth) acrylate monomers such as acrylate; trifluoroethyl (meth) acrylate and the like. In addition, these can be used individually or in combination of 2 or more types.
Among these, an aliphatic (meth) acrylate monomer having an alkyl group having 1 to 18 carbon atoms is preferable, and particularly preferably an alkyl group having 1 to 12 carbon atoms from the viewpoint of hair bundle feeling and re-styling. Aliphatic (meth) acrylate monomers, more preferably aliphatic (meth) acrylate monomers having 4 to 12 carbon atoms in the alkyl group, particularly preferably n-butyl acrylate and 2-ethylhexyl acrylate It is. Also, a combination of 2-ethylhexyl acrylate and methyl methacrylate, or a combination of n-butyl acrylate and methyl methacrylate can be preferably used.

Examples of the functional group-containing monomer (I-2) include monomers having two or more vinyl groups in the molecular structure, glycidyl group-containing monomers, allyl group-containing monomers, hydrolyzable silyl group-containing monomers, and acetoacetyl group-containing monomers. , Hydroxyl group-containing monomers, carboxyl group-containing monomers, and the like.
Among these, it is preferable to use a monomer having two or more vinyl groups in the molecular structure or a hydrolyzable silyl group-containing monomer in terms of improving the washability without degrading the hairstyling property.

Examples of the monomer having two or more vinyl groups in the molecular structure include divinylbenzene, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, ethylene glycol di (meth) acrylate, 1,2-propylene glycol di ( (Meth) acrylate, 1,3-propylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, tri Examples include methylolpropane tri (meth) acrylate and allyl (meth) acrylate.
Among these, ethylene glycol di (meth) acrylate, 1,2-propylene glycol di (meth) acrylate, 1,3-propylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1, 6-Hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate are included in the (meth) acrylic monomer (I-1) and the monomer composition [II]. It is preferable at the point which is excellent in the copolymerizability with a (meth) acrylate type monomer.

Examples of the glycidyl group-containing monomer include glycidyl (meth) acrylate, glycidyl (meth) allyl ether, 3,4-epoxycyclohexyl (meth) acrylate, and the like.

Examples of the allyl group-containing monomer include monomers having two or more allyl groups such as triallyloxyethylene, diallyl maleate, triallyl cyanurate, triallyl isocyanurate, tetraallyloxyethane, allyl glycidyl ether, and allyl acetate. Etc.

Examples of the hydrolyzable silyl group-containing monomer include vinyl silyl group-containing monomers such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, and vinylmethyldimethoxysilane; γ- (meth) (Meth) acryloxy systems such as acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ- (meth) acryloxypropylmethyldiethoxysilane Examples thereof include silyl group-containing monomers.
Among these, the (meth) acryloxy-based silyl group-containing monomer is excellent in copolymerization with the (meth) acrylic monomer (I-1) and the (meth) acrylate-based monomer contained in the monomer composition [II]. Is preferable.

Examples of the acetoacetyl group-containing monomer include acetoacetate vinyl ester, acetoacetate allyl ester, diacetoacetate allyl ester, acetoacetoxyethyl (meth) acrylate, acetoacetoxyethyl crotonate, acetoacetoxypropyl (meth) acrylate, acetoacetoxy Examples thereof include propyl crotonate and 2-cyanoacetoacetoxyethyl (meth) acrylate.

Examples of the hydroxyl group-containing monomer include (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and the like, and protection during emulsion polymerization From the viewpoint of colloid action and washability, 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate are preferred.

Examples of the carboxyl group-containing monomer include (meth) acrylic acid, acrylic acid dimer, crotonic acid, maleic acid, maleic anhydride, fumaric acid, citraconic acid, glutaconic acid, itaconic acid, acrylamide N-glycolic acid, and cinnamon. Among these, acrylic acid and methacrylic acid are preferable from the viewpoint of protective colloidal action during emulsion polymerization and washability.

The content ratio of the (meth) acrylic monomer (I-1) is preferably 80 to 100% by weight, particularly preferably 85 to 99.99% by weight, based on the entire monomer composition [I]. More preferably, it is 90 to 99.9% by weight.
If the content ratio of the (meth) acrylic monomer (I-1) is too small, sufficient hair styling performance tends not to be exhibited. When two or more monomers are included as the (meth) acrylic monomer (I-1), the total content of these monomers is preferably in the above range.

The content of the functional group-containing monomer (I-2) is preferably 0 to 20% by weight, particularly preferably 0.01 to 15% by weight, and more preferably, based on the whole monomer composition [I]. Preferably, the content is 0.1 to 10% by weight.
If the content is too high, the acrylic resin becomes too hard, and sufficient hair strength does not appear and hair styling properties tend to decrease. If the content is too low, the effect of washability tends to be difficult to be exhibited. When two or more types of monomers are included as the functional group-containing monomer (I-2), the total content of these monomers is preferably in the above range.

When the functional group-containing monomer (I-2) includes a monomer having two or more vinyl groups in the molecular structure, the content ratio of the monomer having two or more vinyl groups in the molecular structure is the monomer composition. [I] The content is preferably 0.01 to 10% by weight, particularly preferably 0.05 to 5% by weight, more preferably 0.1 to 3% by weight, based on the total amount of [I].

Further, when the functional group-containing monomer (I-2) includes a hydrolyzed silyl group-containing monomer, the content of the hydrolyzed silyl group-containing monomer is from 0.01 to the entire monomer composition [I]. It is preferably 5% by weight, particularly preferably 0.02 to 3% by weight, more preferably 0.05 to 2% by weight.

In addition, a small amount of styrene monomer such as styrene and α-methylstyrene, vinyl formate, vinyl acetate, vinyl propionate, vinyl valerate, vinyl butyrate, vinyl isobutyrate, and pivalic acid, as long as the effects of the present invention are not impaired. Vinyl ester monomers such as vinyl, vinyl caprate, vinyl laurate, vinyl stearate, vinyl benzoate, vinyl versatate and vinyl 2-ethylhexanoate may be used.

<Monomer composition [II]>
The monomer composition [II] will be specifically described.
Examples of the monomer composition [II] include (meth) acrylic monomer (II-1) and functional group-containing monomer (II-2). The monomer composition [II] may consist of only one or two or more (meth) acrylic monomers (II-1) or only one or two or more functional group-containing monomers (II-2). In addition, it may contain one or more (meth) acrylic monomers (II-1) and one or more functional group-containing monomers (II-2). Of these, the (meth) acrylic monomer (II-1) is preferably the main component.

Examples of the (meth) acrylic monomer (II-1) include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, and n-butyl (meth) acrylate, similar to the (meth) acrylic monomer (I-1). ) Acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, lauryl (meth) acrylate, octyl (meth) acrylate, stearyl (meth) acrylate Aliphatic (meth) acrylate monomers such as; aromatic (meth) acrylate monomers such as phenoxy (meth) acrylate; trifluoroethyl (meth) acrylate, and the like. In addition, these can be used individually or in combination of 2 or more types.
Among these, an aliphatic (meth) acrylate monomer having an alkyl group having 1 to 18 carbon atoms is preferable, and particularly preferably an alkyl group having 1 to 12 carbon atoms from the viewpoint of hair bundle feeling and re-styling. Aliphatic (meth) acrylate monomers, more preferably aliphatic (meth) acrylate monomers having an alkyl group of 1 to 4 carbon atoms, particularly preferably methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate.
In addition, it is also possible to suitably use other (meth) acrylates having methyl methacrylate as a main component.

Examples of the functional group-containing monomer (II-2) include, for example, a monomer having two or more vinyl groups in the molecular structure, a glycidyl group-containing monomer, and an allyl group-containing monomer, similar to the functional group-containing monomer (I-2). , Hydrolyzable silyl group-containing monomers, acetoacetyl group-containing monomers, hydroxyl group-containing monomers, carboxyl group-containing monomers, and the like.
Among these, it is preferable to copolymerize a monomer having two or more vinyl groups or a hydrolyzable silyl group-containing monomer in the molecular structure from the viewpoint of improving the washability without degrading the hairstyling property.

Examples of the monomer having two or more vinyl groups in the molecular structure include divinylbenzene, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, ethylene glycol di (meth) acrylate, 1,2-propylene glycol di ( (Meth) acrylate, 1,3-propylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, tri Examples include methylolpropane tri (meth) acrylate and allyl (meth) acrylate.
Among these, ethylene glycol di (meth) acrylate, 1,2-propylene glycol di (meth) acrylate, 1,3-propylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1, 6-Hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate are included in the (meth) acrylic monomer (II-1) and the monomer composition [I]. It is preferable at the point which is excellent in the copolymerizability with a (meth) acrylate type monomer.

Examples of the glycidyl group-containing monomer include glycidyl (meth) acrylate, glycidyl (meth) allyl ether, 3,4-epoxycyclohexyl (meth) acrylate, and the like.

Examples of the allyl group-containing monomer include monomers having two or more allyl groups such as triallyloxyethylene, diallyl maleate, triallyl cyanurate, triallyl isocyanurate, tetraallyloxyethane, allyl glycidyl ether, and allyl acetate. Etc.

Examples of the hydrolyzable silyl group-containing monomer include vinyl silyl group-containing monomers such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, and vinylmethyldimethoxysilane; γ- (meth) (Meth) acryloxy systems such as acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ- (meth) acryloxypropylmethyldiethoxysilane Examples thereof include silyl group-containing monomers.
Among these, the (meth) acryloxy-based silyl group-containing monomer has excellent copolymerizability with the (meth) acrylic monomer (II-1) and the (meth) acrylate-based monomer contained in the monomer composition [I]. Is preferable.

Examples of the acetoacetyl group-containing monomer include acetoacetate vinyl ester, acetoacetate allyl ester, diacetoacetate allyl ester, acetoacetoxyethyl (meth) acrylate, acetoacetoxyethyl crotonate, acetoacetoxypropyl (meth) acrylate, acetoacetoxy Examples thereof include propyl crotonate and 2-cyanoacetoacetoxyethyl (meth) acrylate.

Examples of the hydroxyl group-containing monomer include (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and the like, and protection during emulsion polymerization From the viewpoint of colloidal action and washability, 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate are preferred.

Examples of the carboxyl group-containing monomer include (meth) acrylic acid, acrylic acid dimer, crotonic acid, maleic acid, maleic anhydride, fumaric acid, citraconic acid, glutaconic acid, itaconic acid, acrylamide N-glycolic acid, and cinnamon. Among these, acrylic acid and methacrylic acid are preferable from the viewpoint of protective colloidal action during emulsion polymerization and washability.

The content ratio of the (meth) acrylic monomer (II-1) is preferably 80 to 100% by weight, particularly preferably 85 to 99.99% by weight, based on the entire monomer composition [II]. More preferably, it is 90 to 99.9% by weight.
When the content ratio of the (meth) acrylic monomer (II-1) is the above lower limit, sufficient hair styling performance tends to be exhibited. When two or more types of monomers are included as the (meth) acrylic monomer (II-1), the total content of these monomers is preferably within the above range.

The content ratio of the functional group-containing monomer (II-2) is preferably 0 to 20% by weight, particularly preferably 0.01 to 15% by weight, more preferably, based on the whole monomer composition [II]. Preferably, the content is 0.1 to 10% by weight.
When the content is too large, the polymerization stability tends to be lowered, and when the content is too small, the effect of the washability tends to be difficult to understand. When two or more types of monomers are included as the functional group-containing monomer (II-2), the total content of these monomers is preferably within the above range.

Further, when the functional group-containing monomer (II-2) contains a monomer having two or more vinyl groups in the molecular structure, the content ratio of the monomer having two or more vinyl groups in the molecular structure is the monomer composition. [II] The content is preferably from 0.01 to 10% by weight, particularly preferably from 0.05 to 5% by weight, and still more preferably from 0.1 to 3% by weight, based on the whole.

Further, when the functional group-containing monomer (II-2) contains a hydrolyzed silyl group-containing monomer, the content ratio of the hydrolyzed silyl group-containing monomer is from 0.01 to the entire monomer composition [II]. It is preferably 5% by weight, particularly preferably 0.02 to 3% by weight, more preferably 0.05 to 2% by weight.

In addition, a small amount of styrenic monomer such as styrene and α-methylstyrene, vinyl formate, vinyl acetate, vinyl propionate, vinyl valerate, vinyl butyrate, vinyl isobutyrate, pivalin as long as the effects of the present invention are not impaired. Vinyl ester monomers such as vinyl acid, vinyl caprate, vinyl laurate, vinyl stearate, vinyl benzoate, vinyl versatate, vinyl 2-ethylhexanoate and the like may be used.

<Other ingredients>
In the acrylic resin emulsion according to the present invention, in addition to the monomer composition [I] and the monomer composition [II], other components can be appropriately used as necessary. Examples of such other components include an emulsifier, a polymerization initiator, a polymerization regulator, and a plasticizer. Among these, it is preferable to use an emulsifier. The emulsifier is preferably a water-soluble polymer, particularly preferably a polyvinyl alcohol resin (hereinafter sometimes referred to as “PVA resin”).
Furthermore, in the present invention, it is preferable that the acrylic resin particles in the acrylic resin emulsion are dispersed and stabilized with a polyvinyl alcohol resin from the viewpoint of good washability.
The dispersion-stabilized state refers to a dispersion state in which the emulsion does not settle and separate even when left at 23 ° C. for 1 month, and maintains a uniform state.

The PVA resin is preferably a PVA resin having the following specific average saponification degree and average polymerization degree.

The average degree of saponification of the PVA resin is preferably 70 to 99.9 mol%, particularly preferably 80 to 99.5 mol%, and further preferably 85 to 99 mol%.
If the average saponification degree is too low, it is difficult for the polymerization to proceed stably, and even when the polymerization is completed, there is a tendency for the storage stability of the emulsion to decrease, and if it is too high, the emulsion stability decreases. There is a tendency that the production of emulsion becomes difficult.

In this specification, the average saponification degree can be obtained according to the saponification degree calculation method described in JIS K 6726 (1994).

The average degree of polymerization of the PVA resin is preferably 50 to 3,000, particularly preferably 100 to 2,000, more preferably 200 to 1,000, and particularly preferably 200. ~ 500.
If the average degree of polymerization is too low, the protective colloid ability at the time of emulsion polymerization will be insufficient and the polymerization will tend not to proceed stably.If it is too high, the reaction system will become unstable due to thickening during the polymerization. Dispersion stability tends to decrease.

In this specification, the average degree of polymerization can be determined according to the method for calculating the average degree of polymerization described in JIS K 6726 (1994).

In the present invention, the PVA-based resin means PVA itself or one modified by, for example, various modified species, and the degree of modification is usually 20 mol% or less, preferably 15 mol% or less, more preferably It is 10 mol% or less.

Examples of the modified PVA resin include an anion modified PVA resin modified with an anionic group such as a carboxylic acid group, a sulfonic acid group, and a phosphoric acid group; modified with a cationic group such as a quaternary ammonium group. Cationic modified PVA resin: Modified PVA resin modified with various functional groups such as acetoacetyl group, diacetone acrylamide group, mercapto group, silanol group, etc .; contains 1,2-diol structural unit in side chain Examples thereof include PVA-based resins.

The PVA resin is preferably a PVA resin containing a 1,2-diol structural unit in the side chain from the viewpoint of excellent dispersion stability when polymerizing a (meth) acrylic monomer, particularly preferably. It is a PVA resin containing a 1,2-diol structural unit represented by the following formula (1).

(In formula (1), R ¹ to R ⁶ each independently represents a hydrogen atom or an organic group, and X represents a single bond or a bond chain.)

In the above formula (1), R ¹ to R ⁶ each independently represents 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 the resin properties are not significantly impaired. The organic group is not particularly limited, but is preferably an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, or a tert-butyl group. You may have substituents, such as a halogeno group, a hydroxyl group, an ester group, a carboxylic acid group, and a sulfonic acid group, as needed.

In the formula (1), X is a single bond or a bond chain, and is preferably a single bond from the viewpoint of set holding power, non-stickiness, familiarity with hair, and the like. The bonding chain is not particularly limited, but hydrocarbons such as alkylene, alkenylene, alkynylene, phenylene and naphthylene (these hydrocarbons may be substituted with halogen such as fluorine, chlorine and bromine). In addition, —O—, — (CH ₂ O) _m —, — (OCH ₂ ) _m —, — (CH ₂ O) _m CH ₂ —, —CO—, —COCO—, —CO (CH ₂ ) _m CO —, —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 (OR) O-, and the like. Here, each R is independently an arbitrary substituent, preferably a hydrogen atom or an alkyl group. M is a natural number. Of these, an alkylene group having 6 or less carbon atoms or —CH ₂ OCH ₂ — is preferable, and a methylene group and —CH ₂ OCH ₂ — are more preferable in terms of viscosity stability at the time of production, heat resistance, and the like.

The PVA resin containing the 1,2-diol structural unit represented by the formula (1) is, for example, (a) a method for saponifying a copolymer of vinyl acetate and 3,4-diacetoxy-1-butene (B) a method of saponifying and decarboxylating a copolymer of vinyl acetate and vinyl ethylene carbonate, and (c) a copolymer of vinyl acetate and 2,2-dialkyl-4-vinyl-1,3-dioxolane Can be obtained by a method of saponifying and deketalizing, and (d) a method of saponifying a copolymer of vinyl acetate and glyceryl monoallyl ether.

The content of the 1,2-diol structural unit in the PVA resin containing the 1,2-diol structural unit represented by the formula (1) is preferably 1 to 15 mol%, particularly preferably 1 to It is 12 mol%, more preferably 2 to 10 mol%, particularly preferably 2 to 9 mol%.
If the content of the 1,2-diol structural unit is too low, the mechanical stability of the emulsion tends to be lowered. If it is too high, the stability during polymerization is lowered, and a stable emulsion having a high nonvolatile content can be obtained. There is a tendency to become difficult.

The content of the side chain 1,2-diol unit in the PVA resin is determined from ¹ H-NMR spectrum (solvent: DMSO-d ₆ , internal standard: tetramethylsilane) of PVA completely saponified. Specifically, it can be calculated from a peak area derived from a hydroxyl proton in the 1,2-diol unit, a methine proton, a methylene proton, a methylene proton in the main chain, or a proton in a hydroxyl group linked to the main chain. That's fine.

The average saponification degree of the PVA-based resin containing the 1,2-diol structural unit represented by the formula (1) is preferably 85 mol% or more, more preferably 86.5 to 99.8 mol. %, Particularly preferably 95 to 99 mol%.
If the average degree of saponification is too small, the stability of the emulsion during polymerization tends to be lowered, making it difficult to obtain the intended emulsion.

Furthermore, the average degree of polymerization of the PVA resin containing the 1,2-diol structural unit represented by the formula (1) is preferably 50 to 3,000, more preferably 100 to 2,500, and still more preferably 200 to 2,000, particularly preferably 200 to 500.
If the average degree of polymerization is too small, it tends to be difficult to industrially produce a PVA resin, and if it is too large, the viscosity of the emulsion tends to be too high, or the polymerization stability of the emulsion tends to decrease. .

Also, the PVA resin is usually made into an aqueous solution using an aqueous medium, and this is used in the process of emulsion polymerization. Here, the aqueous medium refers to water or an alcoholic solvent mainly composed of water, preferably water.

The amount (nonvolatile content) of the PVA resin in the aqueous solution is not particularly limited, but is preferably 5 to 30% by weight from the viewpoint of easy handling.

The amount of the PVA resin used is preferably 0.01 to 40 parts by weight, particularly preferably 0.1 to 100 parts by weight in total of the monomer composition [I] and the monomer composition [II]. -30 parts by weight, more preferably 0.5-20 parts by weight.
If the amount of the PVA resin used is too small, the amount of protective colloid at the time of emulsion polymerization is insufficient, and the polymerization stability tends to decrease. If the amount used is too large, the acrylic resin emulsion is used. The viscosity tends to increase and the stability decreases.

Examples of the emulsifier other than the PVA resin include anionic, cationic, and nonionic surfactants, water-soluble polymers having protective colloid ability other than the PVA resin, and water-soluble oligomers.

Examples of the surfactant include anionic surfactants such as sodium lauryl sulfate and sodium dodecylbenzenesulfonate, and nonionic surfactants such as those having a pluronic type structure and those having a polyoxyethylene type structure. Agents. Moreover, the reactive surfactant which has a radically polymerizable unsaturated bond in a structure can also be used as a surfactant. These may be used alone or in combination of two or more.

The use of the above-mentioned surfactant has the effect of making the emulsion polymerization proceed smoothly, making it easy to control (effect as an emulsifier), and suppressing the generation of coarse particles and block-like substances generated during the polymerization. However, if many of these surfactants are used as emulsifiers, the graft rate tends to decrease. For this reason, when using a surfactant, it is desirable that the amount used is an auxiliary amount with respect to the PVA resin, that is, as small as possible.

Examples of the water-soluble polymer having protective colloid ability other than the PVA-based resin include hydroxyethyl cellulose, polyvinyl pyrrolidone, methyl cellulose and the like. These may be used alone or in combination of two or more. These are effective in that the viscosity is changed by increasing the viscosity of the emulsion or changing the particle size of the emulsion.

As the water-soluble oligomer, for example, a polymer having a hydrophilic group such as a sulfonic acid group, a carboxyl group, a hydroxyl group or an alkylene glycol group is preferable, and a polymer or copolymer having a polymerization degree of about 10 to 500 is preferable. It is mentioned in. Specific examples of the water-soluble oligomer include amide copolymers such as 2-methacrylamide-2-methylpropanesulfonic acid copolymer, sodium methacrylate-4-styrenesulfonate copolymer, styrene / maleic acid copolymer, and the like. Examples include polymers, melamine sulfonic acid formaldehyde condensates, poly (meth) acrylates, and the like. Furthermore, specific examples include a monomer having a sulfonic acid group, a carboxyl group, a hydroxyl group, an alkylene glycol group, and a water-soluble oligomer obtained by previously copolymerizing a radical polymerizable reactive emulsifier alone or with another monomer. It is done. These may be used alone or in combination of two or more.

As the polymerization initiator, those that can be used for usual emulsion polymerization can be used, for example, inorganic peroxides such as potassium persulfate, sodium persulfate, and ammonium persulfate; organic peroxides, azo-based initiators, peroxides Examples thereof include peroxides such as hydrogen and butyl peroxide; and redox polymerization initiators obtained by combining these with reducing agents such as acidic sodium sulfite and L-ascorbic acid. These may be used alone or in combination of two or more.
Among these, ammonium persulfate and potassium persulfate are preferable in terms of easy polymerization.

The polymerization regulator can be appropriately selected from known ones. Examples of such a polymerization regulator include a chain transfer agent and a buffer.

Examples of the chain transfer agent include alcohols such as methanol, ethanol, propanol and butanol; aldehydes such as acetaldehyde, propionaldehyde, n-butyraldehyde, furfural and benzaldehyde; and dodecyl mercaptan, lauryl mercaptan, normal mercaptan, thiol And mercaptans such as glycolic acid, octyl thioglycolate, and thioglycerol. These may be used alone or in combination of two or more. The use of a chain transfer agent is effective in that the polymerization is performed stably, and it is desirable to use it to adjust the degree of polymerization of the acrylic resin.

Examples of the buffer include sodium acetate, ammonium acetate, dibasic sodium phosphate, and sodium citrate. These may be used alone or in combination of two or more.

As the plasticizer, an adipate plasticizer, a phthalic acid plasticizer, a phosphoric acid plasticizer, or the like can be used.

The amount of these other components used can be appropriately selected according to the purpose within a range not impairing the effects of the present invention.

<Method for producing acrylic resin emulsion>
A method for producing an acrylic resin emulsion obtained by emulsion polymerization of the monomer composition [I] and the monomer composition [II] in this order in two steps will be described.

In the acrylic resin emulsion of the present invention, for example, a monomer composition [I] is first emulsion-polymerized using a PVA resin as a dispersion stabilizer to obtain a first emulsion, and then the monomer composition [II]. And emulsion polymerization in the first emulsion.

Usually, the emulsion polymerization is carried out using the above-mentioned other components such as a polymerization initiator, a polymerization regulator, an auxiliary emulsifier, etc., if necessary, in addition to the PVA resin and the monomer component. The polymerization reaction conditions can be appropriately selected according to the type and purpose of the monomer.

As a method of emulsion polymerization, for example, a monomer dropping type emulsion polymerization method in which water and a PVA-based resin are charged in a reaction can and heated to drop a monomer component and a polymerization initiator; An emulsion monomer dropping type emulsion polymerization method in which a mixed monomer is previously dispersed and emulsified with water-soluble polymer having protective colloid ability other than PVA resin and / or PVA resin and water, and then the dispersed / emulsified monomer is dropped. The emulsion monomer dropping polymerization method is advantageous in terms of reactivity when using a hydrophobic monomer, management of the polymerization process, controllability, and the like.
Also, a water-soluble polymer having a protective colloid ability other than PVA resin and / or PVA resin at the end of the polymerization reaction for the purpose of imparting stability to the emulsion and imparting water solubility and / or redispersibility to water. It can also be added later.

The emulsion polymerization process will be described more specifically below.

In the above monomer dropping emulsion polymerization, for example, first, water, a PVA resin, and an auxiliary emulsifier as necessary are charged into a reaction vessel, and this is heated (usually 40 to 90 ° C.), and then the monomer composition [I] Part of the monomer (generally 0.1 to 50% by weight, preferably 1 to 30% by weight, based on the total amount of the monomer composition [I]) and a polymerization initiator are added to the reaction vessel, and initial polymerization is carried out. . Next, the remaining monomer composition of the monomer composition [I] is added to the reaction can in a lump or dropwise, and polymerization is allowed to proceed while further adding a polymerization initiator as necessary. Next, the monomer composition [II] is added to the reaction can all at once or dropwise, and the polymerization is allowed to proceed while further adding a polymerization initiator as necessary. When it is determined that the polymerization reaction is completed, the reaction can is cooled, and the target acrylic resin emulsion can be taken out.

In the emulsion monomer dropping type emulsion polymerization method, for example, first, water, if necessary, a PVA resin and an auxiliary emulsifier are charged in a reaction vessel, and this is heated (usually 40 to 90 ° C.) and then PVA type. Water-soluble polymer having protective colloid ability other than resin and / or PVA resin, part of monomer composition [I] emulsified / dispersed with auxiliary emulsifier and water as necessary (monomer composition [I] total amount In general, 0.1 to 50% by weight, preferably 1 to 30% by weight) and a polymerization initiator are added to the reaction vessel to carry out initial polymerization. Next, the remaining monomer composition of the monomer composition [I] is added to the reaction can in a lump or dropwise, and polymerization is allowed to proceed while further adding a polymerization initiator as necessary. Next, the reactor can be used while the PVA resin and / or the water-soluble polymer having protective colloid ability other than the PVA resin, and the monomer composition [II] emulsified / dispersed with an auxiliary emulsifier and water as necessary are added all at once or dropwise. Polymerization is allowed to proceed while adding a polymerization initiator as necessary. When it is determined that the polymerization reaction is completed, the reaction can is cooled, and the target acrylic resin emulsion can be taken out.

In addition, the initial amount of the monomer composition [I] and the polymerization initiator are added dropwise to the reaction can without performing the initial polymerization, and then the reaction is performed while dropping the total amount of the monomer composition [II] and the polymerization initiator. It can also be carried out by adding to the can. In addition, when the reaction temperature is less than 70 ° C., it is preferable that a redox polymerization reaction system using a reducing agent is used because the reaction proceeds smoothly.

The emulsion polymerization of the monomer composition [I] is usually continued for 5 minutes to 1 hour (preferably 10 minutes to 30 minutes) after the addition of the entire amount of the monomer composition [I] is completed. The polymerization is completed when the polymerization rate of I] exceeds 90% (preferably 95%), and it can be considered that the first emulsion is obtained. If the emulsion composition of the monomer composition [II] is subsequently carried out, Good.

In the present invention, the acrylic resin emulsion obtained by emulsion polymerization is typically uniform milky white, and the average particle size of the acrylic resin in the acrylic resin emulsion is 0.2 to 2 μm. And more preferably 0.3 to 1.5 μm.

Here, the average particle diameter can be measured by a conventional method, for example, a laser analysis / scattering particle size distribution measuring apparatus “LA-950S2” (manufactured by Horiba, Ltd.).

Furthermore, in the present invention, it is determined that at least a part of the PVA-based resin is grafted to the acrylic resin, and the measured value in the storage stability and adhesive strength measurement of the resulting acrylic resin emulsion before drying itself. This is preferable from the viewpoint of less variation.

When the PVA resin is grafted onto the acrylic resin, the value (W) represented by the following formula (2) is preferably 90% by weight or less, more preferably 85% by weight or less, and still more preferably Is 80% by weight or less. In addition, as a minimum, it is 1 weight% normally, Preferably it is 5 weight%, More preferably, it is 10 weight%. This value is a measure of the degree of grafting, and if this value is too low, the degree of grafting is low, the protective colloid action during emulsion polymerization is reduced, and the polymerization stability tends to decrease. If it is too high, it tends to be difficult to form a stable emulsion at a high concentration.

The value (W) of equation (2) is calculated as follows.
That is, a target emulsion or the like is dried at room temperature to prepare a film, and the film is extracted in boiling water and acetone for 8 hours, respectively, to remove ungrafted resin and the like. In this case, the absolute dry weight of the film before extraction is w ₁ (g), and the absolute dry weight of the film after extraction is w ₂ (g), which is obtained from the following formula (2).

Examples of the method of adjusting the value (W) of the above formula (2) include a method of changing the emulsion polymerization temperature or using a trace amount of reducing agent in combination with a persulfate used as a polymerization catalyst. It is done. For example, the value (W) can be increased by increasing the emulsion polymerization temperature, and the value (W) can be decreased by decreasing the emulsion polymerization temperature. When acidic sodium sulfite or the like is used as the reducing agent, the value (W) increases.

In the present invention, various additives may be further added to the acrylic resin emulsion after emulsion polymerization, if necessary. Examples of such additives include organic pigments, inorganic pigments, water-soluble additives, pH adjusters, preservatives, and antioxidants.

Thus, the acrylic resin emulsion according to the present invention can be obtained, and when used, it is preferable to adjust the nonvolatile content to usually 0.1 to 65% by weight.
Further, when such an acrylic resin emulsion is used as a hairdressing agent, when other compounding components such as resins and additives described later are used in combination, the nonvolatile content is usually 30 to 60% by weight. This is preferable in that the use of the resin or additive is not easily restricted.
When such an acrylic resin emulsion is used alone as a hair styling agent, it is preferable that the non-volatile content is usually 1 to 10% by weight because it can be uniformly applied to hair.

By the above method, the acrylic resin emulsion according to the present invention is obtained. Such acrylic resin emulsions are used for hairdressing agents, and hairdressing agents using the emulsions exhibit desired performances such as styling properties, re-styling performance, tactile sensation, and performance to be cleaned.

The hair styling agent according to the present invention only needs to contain the above-mentioned acrylic resin emulsion, and may be an acrylic resin emulsion used alone, or an acrylic resin emulsion and various compounding agents are used in combination. It may be what you did.

In the hair styling agent of the present invention, the acrylic resin emulsion for hair styling agent of the present invention preferably contains 1% by weight or more (in terms of solid content) in the hair styling agent, more preferably 3% by weight or more (in terms of solid content). More preferably, it is 5% by weight or more (in terms of solid content). In addition, as an upper limit, Preferably it is 70 weight% (solid content conversion), More preferably, it is 60 weight% (solid content conversion), More preferably, it is 50 weight% (solid content conversion). If the amount of the acrylic resin emulsion for hairdressing agent of the present invention is too small, the hairstyling power tends to decrease, and if it is too large, the cleaning property tends to decrease.

In the hair styling agent of the present invention, various blending components used in known general hair styling agents such as oils, polyhydric alcohols, lower alcohols, surfactants, ultraviolet absorbers, fragrances, antioxidants are added to the acrylic resin emulsion. An agent, a moisturizer, a refreshing agent, vitamins, a plant extract and the like can be appropriately blended according to the purpose.

Examples of the oil include sunflower oil, cottonseed oil, soybean oil, olive oil, coconut oil, castor oil, jojoba oil, camellia oil, mink oil and the like; beeswax, carnauba wax, candelilla wax, rice bran wax, shellac wax, whale wax, lanolin Waxes such as ceresin, paraffin wax, liquid paraffin, liquid isoparaffin, microcrystalline wax, polyethylene powder, polyethylene wax, Fischer-Tropsch wax, petrolatum, squalane, etc .; lauric acid, myristic acid, palmitic acid, stearin Higher fatty acids such as acid, oleic acid, behenic acid, 2-ethylbutanoic acid, isopentanoic acid, 2-methylpentanoic acid, 2-ethylpentanoic acid, isostearic acid, 12-hydroxystearic acid; lauryl alcohol, Higher alcohols such as stil alcohol, cetyl alcohol, stearyl alcohol, oleyl alcohol, lanolin alcohol, behenyl alcohol, cetostearyl alcohol; ethyl oleate, isopropyl myristate, isopropyl palmitate, myristyl myristate, cetyl palmitate, oleyl oleate, myristine Octyldodecyl acrylate, octyldodecyl oleate, ethyl isostearate, isopropyl isostearate, cetyl 2-ethylhexanoate, cetostearyl 2-ethylhexanoate, glyceryl tri-2-ethylhexanoate, glyceryl triisopalmitate, tetra-2-ethyl Pentaerythritol hexanoate, isocetyl octoate, isostearyl octoate, isocetyl isostearate, Fatty acid ester oils such as octyldodecyl sostearate and octyldodecyl dimethyloctanoate; methylpolysiloxane, highly polymerized methylpolysiloxane, methylphenylpolysiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, octamethylcyclotetrasiloxane, decamethyl Examples thereof include silicone oils such as cyclopentasiloxane, dodecamethylcyclohexasiloxane, methylcyclopolysiloxane, alcohol-modified silicone, alkyl-modified silicone, amino-modified silicone, and epoxy-modified silicone. These may be used alone or in combination of two or more.

The content of such an oil is usually preferably 0.5 to 50% by weight, particularly preferably 1 to 40% by weight, based on the total amount of the hair styling agent, from the viewpoint of emulsification. Moreover, from the viewpoint of reducing the oiliness and stickiness of the hairdressing material, it is preferable to make the content as small as possible, but by using the acrylic resin emulsion of the present invention, the amount of oil used is reduced or not used. can do.

Examples of the polyhydric alcohol include ethylene glycol, dipropylene glycol, propylene glycol, isoprene glycol, glycerin, diglycerin, 1,3-butylene glycol, 1,2-pentanediol, 1,2-hexanediol, 1, Examples include 2-octanediol and 1,2-decanediol. These may be used alone or in combination of two or more.

The content of such a polyhydric alcohol is preferably 0.1 to 20% by weight, particularly preferably 0.5 to 15% by weight, based on the feeling of use, in the total amount of the hairdressing agent.

The acrylic resin emulsion for hairdressing agent of the present invention is used, for example, by diluting the acrylic resin emulsion with water, polyhydric alcohol, lower alcohol or the like as a liquid type hairdressing agent, or in the acrylic resin emulsion, Can be used as a viscous liquid type or cream type hair styling agent.

<Hair styling method>
Examples of the hair styling method using the hair styling agent containing the acrylic resin emulsion for hair styling according to the present invention include a hair styling method including the following steps (A) and (B).
(A) an effective hair amount, a step of applying an acrylic resin emulsion for hairdressing agent obtained by emulsion polymerization of the monomer composition [I] and the monomer composition [II] to the hair;
(B) A step of adjusting the hair into a desired shape before, simultaneously with and after the step (A).
However, the monomer composition [I] and the monomer composition [II] satisfy the following conditions (i) to (iii).
(I) At least one of the monomer composition [I] and the monomer composition [II] contains a (meth) acrylate monomer.
(Ii) The glass transition temperature (Tg2) determined by the Fox formula of the polymer polymerized using the monomer composition [II] is determined by the Fox formula of the polymer polymerized using the monomer composition [I]. 30 ° C. or more higher than the glass transition temperature (Tg1).
(Iii) The blending ratio (weight ratio) of the monomer composition [I] and the monomer composition [II] is monomer composition [I]: monomer composition [II] = 50: 50 to 99: 1.
By styling in this way, a desired hairstyle can be easily formed. And since the hairdressing agent of this invention is excellent in water solubility and / or the redispersibility to water, it can wash away easily.
The effective hair styling amount of the acrylic resin emulsion for hair styling agent is preferably from 0.01 to 1 g per hair bundle having a length of 20 cm and a weight of 1.2 g from the viewpoint of efficient hair styling.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded. In the examples, “parts” and “%” mean weight basis.

First, various acrylic resin emulsions were prepared as follows. The nonvolatile content and viscosity of the acrylic resin emulsion were measured according to the following method, and the glass transition temperature was measured according to the method described above.

<Nonvolatile content>
1 g of the sample was spread on a container of an aluminum foil dish formed to have the same bottom area as a flat weighing bottle 50 mm × 30 mm defined in JIS R 3503 (1994), and weighed accurately. The container was placed in the center of the thermostat, dried at 105 ° C. ± 2 ° C. for 60 ± 5 minutes, allowed to cool in a desiccator, and weighed.
Then, it calculated by the following formula.
N = (Wd / Ws) × 100
(Here, N is the nonvolatile content (%), Wd is the weight (g) of the sample after drying, and Ws is the weight (g) of the sample before drying.)

<Viscosity>
It was measured with a Brookfield viscometer (for example, a BL type viscometer manufactured by Tokyo Keiki Co., Ltd.). About 500 ml of the sample was put in the sample container so that bubbles were not mixed, and the sample container was held so that the liquid level of the sample was lower than the liquid level of the heat transfer medium in the thermostatic bath. The mixture was stirred with a glass rod as necessary, and the sample temperature was measured at 23 ± 1 ° C.
The viscosity was calculated by the following formula (2 significant digits).
η = Kn × θ
(Where η is the viscosity (mPa · s), Kn is a conversion multiplier attached to the viscometer, and θ is the average of the viscometer readings of two measurements.)

<Example 1: Acrylic resin emulsion (a)>
The following emulsion composition X, emulsion Y, and solution Z were prepared using the following monomer composition [I] and monomer composition [II].
Monomer composition [I]: 75 parts of 2-ethylhexyl acrylate, 16 parts of methyl methacrylate, 0.9 part of ethylene glycol dimethacrylate (trade name “Acryester ED”), Tg1 = −52 ° C.
Monomer composition [II]: 9 parts of methyl methacrylate, 0.1 part of ethylene glycol dimethacrylate (manufactured by Mitsubishi Rayon Co., Ltd .; trade name “Acryester ED”), Tg2 = 105 ° C.
Emulsion X: 64 parts of deionized water, 4.5 parts of unmodified PVA resin (average saponification degree 88 mol%, average polymerization degree 500 / manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), monomer composition [I] Emulsified at 1200 rpm for 20 minutes using a turbine blade.
Emulsified liquid Y: 7 parts of deionized water, 0.5 part of unmodified PVA resin (average saponification degree 88 mol%, average polymerization degree 500 / manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), monomer composition [II] Emulsified at 1200 rpm for 20 minutes using a turbine blade.
Solution Z: 2.7 parts of 10% APS (ammonium persulfate) aqueous solution

A stainless steel (SUS) reaction can equipped with a cooling pipe and a stirring blade, PVA containing 1,2-diol structural unit in the side chain in deionized water (72 parts) (average saponification degree 99 mol%, average The polymerization degree is 300, the content of the 1,2-diol structural unit in the side chain is 8 mol% / manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), 10 parts, sodium bisulfite 0.2 parts, sodium carbonate trihydrate 0.4 Was completely dissolved and the temperature was raised to 75 ° C.
First, 11% of Emulsion X and 30% of Solution Z were added all at once to the reaction can and stirred for 45 minutes, then the remaining 89% of Emulsion X and 53% of Solution Z were consumed over 3.1 hours. The first emulsion was obtained by continuing stirring for 10 minutes after completion of the dropping.
Next, the total amount of the emulsion Y and 7% of the solution Z are added dropwise over 0.4 hours, 10 minutes after the completion of the addition, 5% of the solution Z is added all at once, and further 35% after 5 minutes of the solution Z is added all at once. Added and stirred for 45 minutes. During the polymerization, the polymerization was carried out so that the internal temperature of the polymerization solution was maintained at 75 to 80 ° C. The internal temperature was then brought to 55 ° C., and 1.7 parts of a 10% aqueous solution of perbutyl H-69 (manufactured by NOF Corporation) was added all at once, and 3.4 parts of a 5% aqueous solution of vitamin C was divided into two portions for 30 minutes. Every other portion was added and stirred while maintaining the internal temperature of 50 to 55 ° C. for a total of 1 hour to obtain a second emulsion.
The obtained second emulsion was cooled to obtain an acrylic resin emulsion (a) (non-volatile content: 43%; viscosity: 420 mPa · s (B-type viscometer: 12 rpm, 23 ° C.)). The acrylic resin emulsion (a) was dispersed and stabilized.

<Example 2: Acrylic resin emulsion (b)>
In Example 1, 68 parts of 2-ethylhexyl acrylate, 23 parts of methyl methacrylate, 0.9 parts of ethylene glycol dimethacrylate (manufactured by Mitsubishi Rayon Co., Ltd .; trade name “Acryester ED”), Tg1 = − An acrylic resin emulsion (b) (non-volatile content: 43%; viscosity: 1000 mPa · s (B-type viscometer: 12 rpm, 23 ° C.)) was obtained in the same manner as in Example 1 except that the temperature was changed to 43 ° C. The acrylic resin emulsion (b) was dispersed and stabilized.

<Comparative Example 1: Acrylic resin emulsion (a ')>
The following emulsion composition X and solution Z were prepared using the following monomer composition [I].
Monomer composition [I]: 75 parts of 2-ethylhexyl acrylate, 35 parts of methyl methacrylate, 1 part of ethylene glycol dimethacrylate (manufactured by Mitsubishi Rayon Co., Ltd .; trade name “Acryester ED”), Tg1 = −43 ° C.
Emulsion X: 71 parts of deionized water, 5 parts of unmodified PVA resin (average saponification degree 88 mol%, average polymerization degree 500 / manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), and monomer composition [I] are turbine blades Emulsified for 20 minutes at 1200 rpm.
Solution Z: 2.7 parts of 10% APS (ammonium persulfate) aqueous solution

A SUS reaction vessel equipped with a cooling pipe and a stirring blade was added to a PVA resin containing 1,2-diol structural units in the side chain in deionized water (72 parts) (average saponification degree 99 mol%, average polymerization degree). 300, content of side chain 1,2-diol structural unit 8 mol% / manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 10 parts, sodium hydrogen sulfite 0.2 parts, sodium carbonate trihydrate 0.4 parts Was completely dissolved and heated to 75 ° C.
First, 10% of the emulsion X and 30% of the solution Z are added all at once to the reaction can and stirred for 45 minutes, and then the remaining 90% of the emulsion X and 60% of the solution Z are added over 3.5 hours. The solution was added dropwise and polymerized in one step at an internal temperature of 75 to 80 ° C. Ten minutes after the completion of dropping, 5% of the solution Z was added all at once, and further 35 minutes later, 5% of the solution Z was added all at once and stirred for 45 minutes. During the polymerization, the polymerization was carried out so that the internal temperature of the polymerization solution was maintained at 75 to 80 ° C. The internal temperature was then brought to 55 ° C., and 1.7 parts of a 10% aqueous solution of perbutyl H-69 (manufactured by NOF Corporation) was added all at once, and 3.4 parts of a 5% aqueous solution of vitamin C was divided into two portions for 30 minutes. The solution was added in portions and stirred while maintaining the internal temperature of 50 to 55 ° C. for a total of 1 hour.
Thereafter, the mixture was cooled to obtain an acrylic resin emulsion (a ′) (non-volatile content: 43%; viscosity: 490 mPa · s (B-type viscometer 12 rpm, 23 ° C.)). The acrylic resin emulsion (a ′) of Comparative Example 1 was dispersed and stabilized.

<Comparative Example 2: Acrylic resin emulsion (b ')>
In Comparative Example 1, the monomer composition [I] was prepared by adding 68 parts of 2-ethylhexyl acrylate, 32 parts of methyl methacrylate, 1 part of ethylene glycol dimethacrylate (trade name “Acryester ED”), Tg1 = −35 ° C. An acrylic resin emulsion (b ′) (non-volatile content: 43%; viscosity: 810 mPa · s (B-type viscometer: 12 rpm, 23 ° C.)) was obtained in the same manner as in Comparative Example 1 except for changing to The acrylic resin emulsion (b ′) of Comparative Example 2 was dispersed and stabilized.

<Manufacture of hair styling solution for styling performance test>
For Examples 1 and 2, the acrylic resin emulsion (a) and acrylic resin emulsion (b) were used, respectively. For Comparative Examples 1 and 2, the acrylic resin emulsion (a ′) and acrylic resin emulsion ( Each b ′) was diluted with deionized water so that the nonvolatile content was 3%, and each was used as a hair styling solution for styling performance test.

Using the above-described hair styling solution for styling performance test, hair styling performance (setting force), re-hair styling performance (re-setting power, re-setting holding power) and tactile sensation were evaluated as follows.

<Hair styling performance (setting power)>
Apply 0.5g of the hair styling solution for styling performance test to the hair bundle (length 20cm x weight 1.2g; hair bundle shop) with a dropper, and apply it more evenly with fingers with vinyl gloves. Applied. After adjusting with a finger so that the width of the bundle is about 1 cm and drying it with a blow dryer at 100 ° C. for 1 minute, turn the bundling side down with the tip of the hair at an angle of about 45 ° from directly above. And sensory evaluation was performed to determine whether the hair bundle was fixed. The evaluation method is as follows.
(Evaluation criteria)
○… The hair is laid out even if shaken a little.
Δ: Shake slightly to expand the hair tips slightly.
×… The hair ends are loose when not shaken or shake a little.

<Re-styling performance (re-setting power)>
The hair bundle after performing the hair styling evaluation was loosened with a finger, and further spread with a comb, and then the hair bundle state when the hair bundle was made again with the finger was subjected to sensory evaluation. The evaluation method is as follows.
(Evaluation criteria)
○ ... The hair bundles are gathered again (hairs are conditioned).
[Delta] ... Matched, but the hair bundles expanded slightly.
X: It is not a hair bundle and hair is not arranged.
In the above evaluation, “◯” indicates excellent performance, and “Δ” is practically acceptable. In addition, “x” is inferior in performance.

<Re-hair styling performance (re-set holding power)>
The hair bundle state when the hair bundle after light hair styling performance (resetting power) evaluation was shaken lightly was subjected to sensory evaluation. The evaluation method is as follows.
(Evaluation criteria)
○: The hair bundle is almost undisturbed with the hair bundles kept together (re-styling is maintained).
Δ: Hair bundles slightly spread.
X: The hair bundle is greatly separated (re-hair is not held).

<Tactile feel>
The feeling of touch with the fingers was evaluated with respect to the feeling of unity of the hair at the time of evaluation of the above-mentioned hair styling performance (re-setting power). The evaluation method is as follows.
(Evaluation criteria)
○… Moist and smooth.
Δ: Slightly clumsy.
× ...

<Manufacture of hair conditioner solution for cleaning performance test>
For Examples 1 and 2, acrylic resin emulsion (a) and acrylic resin emulsion (b), respectively, and for Comparative Examples 1 and 2, acrylic resin emulsion (a ′) and acrylic resin emulsion, respectively. (B ′) was used as it was to obtain a hair styling solution for cleaning performance test.

<Performance to be cleaned (hot water)>
The hair conditioner solution for cleaning performance test is applied to a 50 μm thick PET (polyethylene terephthalate) film with a 100 μm applicator and dried at 23 ° C. and 50% RH for 30 minutes to obtain a coating film having a thickness of about 25 μm (when dried). It was. Put a drop of 60 ° C deionized water on the coating film with a dropper and rub it once with a finger to draw a circle with a diameter of about 1 cm. Pulp waste cloth (Nippon Paper Crecia Co., Ltd., "Kimwipe") (Registered trademark)). Thereafter, the operation of dropping one drop of 60 ° C. deionized water with a dropper and rubbing with a finger was repeated a total of 10 times. The degree of cleaning of the coating-like hair styling solution was visually evaluated. The evaluation method is as follows.
(Evaluation criteria)
○ 70% to 100% wiped off.
Δ: Wipe off from 30% to less than 70%.
X: Wiped off from 0 to less than 30%.

<Washable performance (cold water)>
The hair conditioner solution for cleaning performance test is applied to a 50 μm thick PET (polyethylene terephthalate) film with a 100 μm applicator and dried at 23 ° C. and 50% RH for 30 minutes to obtain a coating film having a thickness of about 25 μm (when dried). It was. After dropping 1 drop of deionized water at 15 ° C. onto the coating film with a dropper, after 1 minute, lightly tapping 10 times with a finger, pulp waste (Nippon Paper Crecia Co., Ltd., “Kimwipe” (registered trademark) )). The degree of cleaning of the coating-like hair styling solution was visually evaluated. The evaluation method is as follows.
(Evaluation criteria)
○ 70% to 100% wiped off.
Δ: Wipe off from 30% to less than 70%.
X: Wiped off from 0 to less than 30%.

Table 1 shows the results of tests using the compositions of Examples 1 and 2 and Comparative Examples 1 and 2, the glass transition temperature, and the hairdressing agent solution.

In the hair styling agent using the acrylic resin emulsion obtained by the two-stage polymerization of Examples 1 and 2, the styling performance (hair styling performance, re-hair styling performance, and tactile sensation) and the performance to be washed are excellent in balance. I understand.

On the other hand, the acrylic resin emulsions obtained by the non-multistage polymerization of Comparative Examples 1 and 2 have good hair styling performance, re-hair styling properties, and tactile sensation, but are inferior in washing performance, particularly washability in cold water. I know that there is.

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on a Japanese patent application filed on March 7, 2014 (Japanese Patent Application No. 2014-044861), the contents of which are incorporated herein by reference.

The acrylic resin emulsion for hairdressing agents of the present invention has a well-balanced balance between styling performance (hairstyling performance, re-styling performance, and tactile sensation) and performance to be washed, so various compounding agents can be used in combination and applied to various dosage forms. Is a useful thing that can be.

Claims (7)

1. An acrylic resin emulsion for a hair styling agent obtained by emulsion polymerization of a monomer composition [I] and a monomer composition [II],
   An acrylic resin emulsion for a hair conditioner, wherein the monomer composition [I] and the monomer composition [II] satisfy the following conditions (i) to (iii):
   (I) At least one of the monomer composition [I] and the monomer composition [II] contains a (meth) acrylate monomer.
   (Ii) The glass transition temperature (Tg2) determined by the Fox formula of the polymer polymerized using the monomer composition [II] is determined by the Fox formula of the polymer polymerized using the monomer composition [I]. 30 ° C. or more higher than the glass transition temperature (Tg1).
   (Iii) The blending ratio (weight ratio) of the monomer composition [I] and the monomer composition [II] is monomer composition [I]: monomer composition [II] = 50: 50 to 99: 1.
2. 2. The acrylic resin emulsion for hairdressing agent according to claim 1, wherein the glass transition temperature (Tg1) is 0 ° C. or lower and the glass transition temperature (Tg2) is 30 ° C. or higher.
3. The acrylic resin emulsion for hairdressing agents according to claim 1 or 2, wherein the acrylic resin particles in the acrylic resin emulsion are dispersed and stabilized by a polyvinyl alcohol resin.
4. The acrylic resin emulsion for hairdressing agents according to claim 3, wherein the polyvinyl alcohol-based resin contains a side chain 1,2-diol structural unit represented by the following formula (1).
   

   

   (In formula (1), R ¹ to R ⁶ each independently represents a hydrogen atom or an organic group, and X represents a single bond or a bond chain.)
5. Using only the monomer composition [I] and the monomer composition [II], the monomer composition [I] is first subjected to emulsion polymerization, and then the monomer composition [II] is subjected to emulsion polymerization. The acrylic resin emulsion for hairdressing agents according to any one of claims 1 to 4.
6. A hair styling agent comprising the acrylic resin emulsion for hair styling agent according to any one of claims 1 to 5.
7. A hair styling method comprising the following step (A) and step (B).
   (A) an effective hair amount, a step of applying an acrylic resin emulsion for hairdressing agent obtained by emulsion polymerization of the monomer composition [I] and the monomer composition [II] to the hair;
   (B) A step of adjusting the hair into a desired shape before, simultaneously with and after the step (A).
   However, the monomer composition [I] and the monomer composition [II] satisfy the following conditions (i) to (iii).
   (I) At least one of the monomer composition [I] and the monomer composition [II] contains a (meth) acrylate monomer.
   (Ii) The glass transition temperature (Tg2) determined by the Fox formula of the polymer polymerized using the monomer composition [II] is determined by the Fox formula of the polymer polymerized using the monomer composition [I]. 30 ° C. or more higher than the glass transition temperature (Tg1).
   (Iii) The blending ratio (weight ratio) of the monomer composition [I] and the monomer composition [II] is monomer composition [I]: monomer composition [II] = 50: 50 to 99: 1.