JP2022016102A - Base agent for water-in-oil emulsion cosmetic compositions, and water-in-oil emulsion cosmetic composition containing the base agent - Google Patents

Abstract

To provide: a novel base agent which is capable of thickening a water-in-oil emulsion cosmetic composition that contains a silicone oil; and a water-in-oil emulsion cosmetic composition containing a silicone oil, the water-in-oil emulsion cosmetic composition being thickened with the base agent.SOLUTION: A base agent for water-in-oil emulsion cosmetic compositions according to the present disclosure contains a silicone oil, a polar oil and an oil-soluble copolymer which has a monomer unit that is composed of a specific hydrophilic monomer and a monomer unit that is composed of a specific hydrophobic monomer.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to water-in-oil emulsified cosmetics.

For example, in the field of cosmetics, water-in-oil emulsified cosmetics that can impart not only oil and oil-soluble components but also water and water-soluble components to the skin are used. Then, in order to improve the usability of the cosmetic, an attempt to thicken or gel the water-in-oil emulsified cosmetic has been studied.

Patent Document 1 describes (A) 6 to 40% by mass of an ultraviolet absorber, (B) an organically modified clay mineral such as Benton, and (C) 0.1 to 15% by mass of an oil phase increase other than the above (B). It contains a viscous agent, (D) a silicone-based surfactant having an HLB of less than 8 by weight of 0.1 to 8% by mass, (E) a spherical resin powder, and (F) a volatile silicone oil. Water-in-oil emulsified sunscreen cosmetics having a ratio of (C) total amount with ingredients] / [(G) total amount of non-volatile liquid oil other than silicone oil] 0.04 or more and less than 0.68 It has been disclosed.

Patent Document 2 describes a water-in-oil emulsified cosmetic containing an oily gelling agent composed of a copolymer composed of a specific hydrophobic monomer and a specific hydrophilic monomer, and an oil component such as a hydrocarbon oil. It has been disclosed.

Patent Document 3 describes cosmetic oil thickeners, hydrocarbon oils, and the like, which are composed of a copolymer composed of an easily crystalline hydrophobic monomer, a poorly crystalline hydrophobic monomer, and a hydrophilic monomer. Water-in-oil emulsified cosmetics containing the above oils are disclosed.

Japanese Unexamined Patent Publication No. 2017-210492 International Publication No. 2016/098456 Japanese Unexamined Patent Publication No. 2019-206515

When thickening silicone oil, organically modified clay minerals such as Benton as described in Patent Document 1 have generally been used.

It is known that the copolymer composed of the specific monomers described in Patent Documents 2 and 3 can be used as an oil gelling agent or an oil thickener, and such a copolymer is a silicone oil. Due to its low compatibility with, it is typically not used as a thickener or gelling agent for water-in-oil emulsified cosmetics containing silicone oil.

For this reason, it has been desired to increase the variation in thickening of the system containing silicone oil so that it can be applied to various cosmetics.

Therefore, the subject of the present disclosure is a novel base capable of thickening a water-in-oil emulsified cosmetic containing silicone oil, and water in oil containing a silicone oil thickened using the base. It is to provide emulsified cosmetics.

式１中、
Ｒ^１は、水素原子、グリセリル基、炭素原子数１～４の直鎖状若しくは分岐状のヒドロキシアルキル基、又は－（Ｃ_３Ｈ_６Ｏ）_ｎＨで示され、ｎが２～１０の整数であるポリプロピレングリコール基であり、かつ
Ｒ^２は、水素原子又はメチル基であり、

式２中、
Ｒ^３は、水素原子又はメチル基であり、かつ
Ｒ^４は、炭素原子数１～４の直鎖状若しくは分岐状のアルキル基若しくはヒドロキシアルキル基、又は下記の式３の置換基である。

式４中、
Ｒ^５は、炭素原子数１６～２２の直鎖状又は分岐状のアルキル基であり、かつ
Ｒ^６は、水素原子又はメチル基である。
〈態様２〉
前記式１のモノマーが、（メタ）アクリル酸２－ヒドロキシエチル、（メタ）アクリル酸グリセリル、（メタ）アクリル酸ＰＰＧ－６、（メタ）アクリル酸２－ヒドロキシプロピル、（メタ）アクリル酸２－ヒドロキシ－２－メチルプロピル、及び（メタ）アクリル酸から選択される少なくとも一種であり、かつ、前記式２のモノマーが、Ｎ－（２－ヒドロキシエチル）（メタ）アクリルアミド、Ｎ－イソプロピル（メタ）アクリルアミド、及び２－（メタ）アクリルアミド－２－メチルプロパンスルホン酸から選択される少なくとも一種である、態様１に記載の基剤。
〈態様３〉
前記式４のモノマーが、（メタ）アクリル酸セチル、（メタ）アクリル酸ステアリル、及び（メタ）アクリル酸ベヘニルから選択される少なくとも一種である、態様１又は２に記載の基剤。
〈態様４〉
前記油溶性共重合体において、前記親水性モノマーのモノマー単位が、３０～５０モル％の範囲で含まれており、前記疎水性モノマーのモノマー単位が、５０～７０モル％の範囲で含まれている、態様１～３のいずれかに記載の基剤。
〈態様５〉
前記シリコーン油が、ジメチルシリコーン、メチルフェニルポリシロキサン、及び環状ポリシロキサンから選択される少なくとも一種である、態様１～４のいずれかに記載の基剤。
〈態様６〉
前記極性油は、ＩＯＢ値が０．１０以上の極性油である、態様１～５のいずれかに記載の基剤。
〈態様７〉
前記極性油が、オクチルメトキシシンナメート、ジピバリン酸トリプロピレングリコール、エチルヘキサン酸セチル、リンゴ酸ジイソステアリル、及びサリチル酸オクチルから選択される少なくとも一種である、態様６に記載の基剤。
〈態様８〉
前記シリコーン油が、５０質量％以上含まれている、態様１～７のいずれかに記載の基剤。
〈態様９〉
前記シリコーン油と前記極性油との質量比が、９：１～４：１である、態様１～８のいずれかに記載の基剤。
〈態様１０〉
水を添加したときに増粘する、態様１～９のいずれかに記載の基剤。
〈態様１１〉
態様１～１０のいずれかに記載の基剤と、
前記基剤中に分散し、かつ、水を含む水滴と、
を含む、
油中水型乳化化粧料。
〈態様１２〉
前記油溶性共重合体の含有量が、０．１質量％以上である、態様１１に記載の化粧料。
〈態様１３〉
前記シリコーン油の含有量が、１０質量％以上である、態様１１又は１２に記載の化粧料。
〈態様１４〉
顔料をさらに含む、態様１１～１３のいずれかに記載の化粧料。
〈態様１５〉
ファンデーションとして使用される、態様１４に記載の化粧料。 <Aspect 1>
Silicone oil,
Polar oil, as well as
An oil-soluble copolymer having a monomer unit composed of at least one hydrophilic monomer selected from the following formulas 1 and 2 and a monomer unit composed of the hydrophobic monomer of the following formula 4.
including,
Water-in-oil emulsified cosmetic base:

In formula 1,
R ¹ is represented by a hydrogen atom, a glyceryl group, a linear or branched hydroxyalkyl group having 1 to 4 carbon atoms, or-(C _{3H 6} O) _n H, where n is an integer of 2 to 10. Is a polypropylene glycol group, and ^R2 is a hydrogen atom or a methyl group.

In formula 2,
R ³ is a hydrogen atom or a methyl group, and R ⁴ is a linear or branched alkyl group or hydroxyalkyl group having 1 to 4 carbon atoms, or a substituent of the following formula 3.

In formula 4,
R ⁵ is a linear or branched alkyl group having 16 to 22 carbon atoms, and R ⁶ is a hydrogen atom or a methyl group.
<Aspect 2>
The monomer of the formula 1 is 2-hydroxyethyl (meth) acrylate, glyceryl (meth) acrylate, PPG-6 (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate. At least one selected from hydroxy-2-methylpropyl and (meth) acrylic acid, and the monomer of the formula 2 is N- (2-hydroxyethyl) (meth) acrylamide, N-isopropyl (meth). The base according to embodiment 1, which is at least one selected from acrylamide and 2- (meth) acrylamide-2-methylpropanesulfonic acid.
<Aspect 3>
The base according to aspect 1 or 2, wherein the monomer of the formula 4 is at least one selected from cetyl (meth) acrylate, stearyl (meth) acrylate, and behenyl (meth) acrylate.
<Aspect 4>
In the oil-soluble copolymer, the monomer unit of the hydrophilic monomer is contained in the range of 30 to 50 mol%, and the monomer unit of the hydrophobic monomer is contained in the range of 50 to 70 mol%. The base according to any one of aspects 1 to 3.
<Aspect 5>
The base according to any one of aspects 1 to 4, wherein the silicone oil is at least one selected from dimethyl silicone, methylphenyl polysiloxane, and cyclic polysiloxane.
<Aspect 6>
The base according to any one of aspects 1 to 5, wherein the polar oil is a polar oil having an IOB value of 0.10 or more.
<Aspect 7>
The base according to embodiment 6, wherein the polar oil is at least one selected from octylmethoxycinnamate, tripropylene glycol dipivalate, cetyl ethylcaproate, diisostearyl malate, and octyl salicylate.
<Aspect 8>
The base according to any one of aspects 1 to 7, wherein the silicone oil is contained in an amount of 50% by mass or more.
<Aspect 9>
The base according to any one of aspects 1 to 8, wherein the mass ratio of the silicone oil to the polar oil is 9: 1 to 4: 1.
<Aspect 10>
The base according to any one of aspects 1 to 9, which thickens when water is added.
<Aspect 11>
The base according to any one of aspects 1 to 10 and
Water droplets dispersed in the base and containing water,
including,
Water-in-oil emulsified cosmetics.
<Aspect 12>
The cosmetic according to aspect 11, wherein the content of the oil-soluble copolymer is 0.1% by mass or more.
<Aspect 13>
The cosmetic according to aspect 11 or 12, wherein the content of the silicone oil is 10% by mass or more.
<Aspect 14>
The cosmetic according to any one of aspects 11 to 13, further comprising a pigment.
<Aspect 15>
The cosmetic according to aspect 14, which is used as a foundation.

According to the present disclosure, a novel base capable of thickening water-in-oil emulsified cosmetics containing silicone oil, and water-in-oil emulsification containing silicone oil thickened using the base. Cosmetics can be provided.

(A) is a schematic diagram of a base in which the oil-soluble copolymer of the present disclosure is blended in a continuous phase composed of silicone oil, and (b) is a schematic diagram of a base obtained by adding water to the base of (a). It is a schematic diagram of the water-in-oil emulsified cosmetics prepared in the above. (A) is a schematic diagram of a base in which the oil-soluble copolymer of the present disclosure is blended in a continuous phase composed of silicone oil and polar oil, and (b) is a schematic diagram of water as the base of (a). It is a schematic diagram of a water-in-oil emulsified cosmetic prepared by adding.

Hereinafter, embodiments of the present disclosure will be described in detail. The present disclosure is not limited to the following embodiments, and can be variously modified and implemented within the scope of the spirit of the invention.

The water-in-oil emulsified cosmetic base of the present disclosure (sometimes referred to simply as "base") is a silicone oil, a polar oil, and at least one hydrophilic selected from the above formulas 1 and 2. It contains an oil-soluble copolymer having a monomer unit composed of a sex monomer and a monomer unit composed of a hydrophobic monomer of the above formula 4.

Although not limited by the principle, it is considered that the principle of action for obtaining a thickened water-in-oil emulsified cosmetic by adding water to a base containing silicone oil is as follows.

As described in Patent Document 2, the oil-soluble copolymer of the present disclosure is gelled, which is a kind of thickening, with respect to hydrocarbon oils such as liquid paraffin and ester oils such as cetyl 2-ethylhexanoate. It is known that it can cause. However, as described in Patent Document 2, this oil-soluble copolymer has low compatibility with silicone oil. Therefore, for example, when this oil-soluble copolymer is blended with silicone oil such as dimethylpolysiloxane, the oil-soluble copolymer is blended. As shown in FIG. 1 (a), a precipitate of only the polymer of the oil-soluble copolymer 11 was likely to be formed.

When water is added to a base containing such a precipitated oil-soluble copolymer and silicone oil, the precipitated state can be eliminated and an emulsion can be obtained, but the obtained water in oil can be obtained. The type emulsified cosmetic was not thickened and exhibited a silky state, and was in an unstable emulsified state in which it separated immediately after being allowed to stand. This is because the oil-soluble copolymer has a site composed of a specific hydrophilic monomer, and therefore, as shown in FIG. 1 (b), the interface between the aqueous phase (water droplet 13) and the oil phase. It is considered that the oil-soluble copolymer 11 is arranged in the vicinity. On the other hand, the site composed of a specific hydrophobic monomer is difficult to spread in the silicone oil which is difficult to be compatible with each other, and it is difficult to form a network structure for taking in the oil due to the site. It is considered that the polymer is difficult to thicken the water-in-oil emulsified cosmetic containing silicone oil.

The bases of the present disclosure contain polar oils in addition to silicone oils. This polar oil is easily compatible with a portion of the oil-soluble copolymer composed of a specific hydrophobic monomer. For example, the oil-soluble copolymer and the polar oil are blended in an oil containing a high amount of silicone oil. However, as in the case of silicone oil alone, the thickening effect of the base was poor, and in some cases, a gel or a swollen layer containing a part of the oil was formed. However, when the present inventor prepares a water-in-oil emulsified cosmetic by adding water to such a base, surprisingly, in the case of such a cosmetic, thickening can be exhibited. I found.

In a base containing silicone oil and polar oil, the moiety of the oil-soluble copolymer composed of a specific hydrophobic monomer is more likely to spread in the oil phase than in the case of a base containing only silicone oil as the oil phase. Therefore, as shown in FIG. 2A, oil content is taken in to some extent even in a place where the oil-soluble copolymer 21 is precipitated, and a gel or a swollen layer is formed to locally thicken the viscosity. However, it is considered that such thickening action does not contribute to the thickening of the entire base. On the other hand, when water is added and emulsified, the emulsified water droplets are dispersed throughout the system, and accordingly, the oil-soluble copolymer arranged near the interface between the aqueous phase and the oil phase is also dispersed throughout the system. It is thought that it will be. Further, the portion of the oil-soluble copolymer composed of a specific hydrophobic monomer is more likely to spread in the oil phase when the oil phase contains silicone oil and polar oil than when the oil phase contains only silicone oil. As a result, as shown in FIG. 2B, the site composed of a specific hydrophobic monomer spread around the water droplet 23 forms a network structure in the entire system with the water droplet 23 as a cross-linking point to release oil. In order to retain it, we believe that water-in-oil emulsified cosmetics containing silicone oil can be thickened.

Further, in the water-in-oil emulsified cosmetic prepared by using the base of the present disclosure, in addition to the increase in viscosity, the hydrophobic monomer unit existing so as to spread in the oil phase becomes a steric obstacle and is adjacent. It is considered that the emulsification stability of cosmetics is improved because the coalescence of water droplets is suppressed.

The definitions of terms in this disclosure are as follows.

In the present disclosure, the "hydrophilic monomer" is intended to be a monomer that dissolves in water at an arbitrary ratio, and the "hydrophobic monomer" is intended to be another monomer, that is, a monomer that is basically immiscible with water. ..

In the present disclosure, "(meth) acrylic" means acrylic or methacrylic.

<< Base for water-based emulsified cosmetics in oil >>
The water-in-oil emulsified cosmetic base of the present disclosure comprises a monomer unit composed of a silicone oil, a polar oil, and at least one hydrophilic monomer selected from the above-mentioned formulas 1 and 2, and the above-mentioned. It contains an oil-soluble copolymer having a monomer unit composed of the hydrophobic monomer of the formula 4, and has a performance of thickening when water is added.

<Silicone oil>
The blending amount of the silicone oil in the base of the present disclosure is not particularly limited, and may be, for example, 50% by mass or more, 55% by mass or more, or 60% by mass or more with respect to the total amount of the base. It can be 80% by mass or less, 75% by mass or less, or 70% by mass or less.

Alternatively, the blending amount of the silicone oil can be, for example, larger than the blending amount of the polar oil to be blended at the same time. As mentioned above, it can be 70% by mass or more, or 75% by mass or more, and can be 95% by mass or less, 90% by mass or less, or 85% by mass or less.

The silicone oil is not particularly limited, and is, for example, dimethyl silicone (sometimes referred to as "dimethylpolysiloxane" or "dimethicone"); trimethylpentaphenyltrisiloxane, diphenyldimethicone, diphenylsiloxyphenyltrimethicone, phenyltrimethicone, Methylphenylpolysiloxane such as phenyldimethicone (sometimes referred to as "methylphenylsilicone"); cyclic polysiloxane ("cyclic silicone") such as octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane. ); Methylhydrogenpolysiloxane; Perfluorooctylethyl / diphenyldimethicone and the like can be mentioned. These can be used alone or in combination of two or more. Among them, at least one selected from dimethyl silicone, methylphenyl polysiloxane, and cyclic polysiloxane is preferable from the viewpoint of thickening viscosity, emulsion stability, etc., and further, cosmetics can be used as a liquid foundation. Dimethylsilicone is more preferable from the viewpoint of separation resistance (crack resistance) and the like when prepared.

<Polar oil>
When the base contains only silicone oil as an oil, it cannot be significantly thickened even if water is added in combination with the oil-soluble copolymer of the present disclosure. That is, the polar oil blended in the base of the present disclosure can, so to speak, function as a binder component for thickening the silicone oil and the oil-soluble copolymer.

The blending amount of the polar oil is not particularly limited, and may be, for example, 5.0% by mass or more, 10% by mass or more, or 15% by mass or more, and 30% by mass or less, based on the total amount of the base. , 25% by mass or less, or 20% by mass or less.

Alternatively, the blending amount of the polar oil can be, for example, 5.0% by mass or more, 10% by mass or more, or 15% by mass or more, and 45% by mass or less, 40% by mass, based on the total amount of the oil content. Hereinafter, it can be 35% by mass or less, 30% by mass or less, or 25% by mass or less.

The mixing ratio of the silicone oil and the polar oil is not particularly limited, but the silicone oil and the polar oil are polar from the viewpoint of emulsion stability, for example, separation resistance (crack resistance) when the cosmetic is prepared as a liquid foundation. The mass ratio with oil is preferably in the range of 9: 1 to 4: 1 (8: 2), more preferably in the range of 9: 1 to 8.5: 1.5.

The polar oil blended in the base of the present disclosure is not particularly limited as long as it can function as a binder component for thickening, and for example, a polar oil having an IOB value of 0.10 or more may be adopted. can.

The IOB value of the polar oil can be, for example, 0.11 or more, 0.12 or more, 0.13 or more, 0.14 or more, or 0.15 or more, and 0.65 or less and 0.60 or less. , 0.55 or less, 0.50 or less, 0.45 or less, or 0.40 or less. Among them, the IOB value of the polar oil is preferably 0.15 or more and 0.55 or less, and more preferably 0.20 or more and 0.55 or less from the viewpoint of long-term viscosity increasing performance or emulsion stabilizing performance. , 0.20 or more and 0.50 or less are particularly preferable.

Here, the IOB value is an abbreviation for Organic / Organic Balance (inorganic / organic ratio), which is a value indicating the ratio of the inorganic value to the organic value, and is an index indicating the degree of polarity of the organic compound. Is to be. Specifically, the IOB value is expressed as IOB value = inorganic value / organic value. Regarding each of the "inorganic value" and the "organic value", for example, the "organic value" is 20 for one carbon atom in the molecule, the "inorganic value" is 100 for one hydroxyl group, and so on. "Inorganic value" and "organic value" are set according to the atom or functional group, and the "inorganic value" and "organic value" of all the atoms and functional groups in the organic compound are integrated. Can be used to calculate the IOB value of the organic compound (see, for example, Yoshio Koda, "Organic Conceptual Diagram-Basics and Applications-", pp. 11-17, Sankyo Publishing, 1984).

Examples of polar oils satisfying such IOB value conditions include oleic acid (IOB value = 0.42), isostearic acid (IOB value = 0.43), isopropyl myristate (IOB value = 0.18), and the like. Octyl palmitate (IOB value = 0.13), isopropyl palmitate (IOB value = 0.16), butyl stearate (IOB value = 0.14), hexyl laurate (IOB value = 0.17), myristic acid Myristyl (IOB value = 0.11), decyl oleate (IOB value = 0.11), isononyl isononanoate (IOB value = 0.20), isotridecyl isononanoate (IOB value = 0.15), cetyl ethylhexanate (IOB value = 0.13), pentaerythrityl tetraethylhexanoate (IOB value = 0.35), diethylhexyl succinate (IOB value = 0.32), glycol distearate (IOB value = 0.16), diisostearate Glyceryl acid (IOB value = 0.29), Neopentyl glycol dicaprate (IOB value = 0.25), Diisostearyl malate (IOB value = 0.28), Trimethylolpropane triisostearate (IOB value = 0) .16), Glyceryl tri2-ethylhexanoate (triethylhexanoin) (IOB value = 0.35), Trimethylolpropane trioctanoate (IOB value = 0.33), Trimethylolpropane triisostearate (IOB value = 0) .16), diisobutyl adipate (IOB value = 0.46), N-lauroyl-L-glutamic acid-2-octyldodecyl ester (IOB value = 0.29), 2-hexyldecyl adipate (IOB value = 0. 16), diisopropyl sebacate (IOB value = 0.40), octylmethoxycinnamate (sometimes referred to as "ethylhexyl methoxycinnamate") (IOB value = 0.28), olive oil (IOB value = 0.16). ), Himasi oil (IOB value = 0.43), decyltetradecanol (IOB value = 0.21), octyldodecanol (IOB value = 0.26), oleyl alcohol (IOB value = 0.28), palmitin 2-Ethylhexyl acid (IOB value = 0.13), 2-ethylhexyl ethylhexanoic acid (IOB value = 0.2), Triisostea (IOB value = 0.16), Tripropylene glycol dipivalate ("PPG-dipivalate" 3 ”(IOB value = 0.52), octyl salicylate (IOB) = 0.60), tri (caprylic acid / capric acid) glyceryl (IOB value = 0.33) and the like. These can be used alone or in combination of two or more. Among them, at least one selected from octylmethoxycinnamate, tripropylene glycol dipivalate, cetyl ethylhexanate, diisostearyl malate, and octyl salicylate is preferable from the viewpoint of thickening viscosity, emulsion stability, and the like, and octylmethoxy is preferable. At least one selected from cinnamate, tripropylene glycol dipivalate, and diisostearyl malate is more preferable, and further, for example, from the viewpoint of separation resistance (crack resistance) when cosmetics are prepared as a liquid foundation. Therefore, octylmethoxycinnamate is particularly preferable.

<Any oil content>
The oil content in the base of the present disclosure may be only silicone oil and polar oil, but an oil component other than silicone oil and polar oil may be optionally blended as long as it does not affect the effect of the present invention. May be good. Examples of such oils include hydrocarbon oils, higher alcohols, and oil-soluble polyhydric alcohols. These can be used alone or in combination of two or more.

Examples of the hydrocarbon oil include liquid paraffin, tetraisobutane, hydrogenated polydecene, olefin oligomer, isododecane, isohexadecane, squalane, hydrogenated polyisobutane and the like.

Examples of the higher alcohol include isostearyl alcohol and oleyl alcohol.

Examples of the oil-soluble polyhydric alcohol include polybutylene glycol and the like.

When such an arbitrary oil content is blended in the base, the oil content can be blended in the range of 15% by mass or less, 10% by mass or less, or 5.0% by mass or less with respect to the total amount of the base. Alternatively, it can be blended in the range of 10% by mass or less, 5.0% by mass or less, or 1.0% by mass or less with respect to the total amount of oil. The lower limit of the blending amount of any oil is not particularly limited, but may be more than 0% by mass or 0.1% by mass or more with respect to the total amount of the base or the oil.

<Oil-soluble copolymer>
The base of the present disclosure contains an oil-soluble copolymer that can function as a thickener in a water-in-oil emulsified cosmetic. Such an oil-soluble copolymer contains at least a monomer unit composed of at least one hydrophilic monomer selected from the above formulas 1 and 2 and a monomer unit composed of the hydrophobic monomer of the above formula 4. Have. Each of these monomer units may be composed of a single monomer unit, or may be composed of two or more kinds of monomer units. For example, the hydrophilic monomer unit may be composed of one kind of monomer unit, and the hydrophobic monomer unit may be composed of two kinds of monomer units.

The polymerization form of the oil-soluble copolymer is not particularly limited, and for example, a random type, a block type, or the like can be adopted, but the random type is preferable from the viewpoint of easiness of synthesis.

The ratio of the monomer unit composed of the hydrophilic monomer to the monomer unit composed of the hydrophobic monomer in the oil-soluble copolymer is not particularly limited, but is, for example, from the viewpoint of viscosity thickening, emulsion stability and the like. , The monomer unit of the hydrophilic monomer may be contained in an amount of 30 mol% or more, 32 mol% or more, 35 mol% or more, or 40 mol% or more, and 50 mol% or less, 48 mol% or less, or 45. It may be contained in an amount of mol% or less. From the viewpoint of thickening viscosity, emulsion stability, solubility in oil, etc., the monomer unit of the hydrophobic monomer may be contained in an amount of 50 mol% or more, 52 mol% or more, or 55 mol% or more, and 70. It may be contained in an amount of mol% or less, 68 mol% or less, 65 mol% or less, or 60 mol% or less.

The content of the oil-soluble copolymer can be 0.1% by mass or more, 0.5% by mass or more, or 1.0% by mass or more, and 10% by mass or less, based on the total amount of the base. , 5.0% by mass or less, or 3.0% by mass or less.

The ratio of the oil-soluble copolymer to the total amount of oil shall be 0.5% by mass or more, 0.7% by mass or more, 1.0% by mass or more, 1.2% by mass or more, or 1.5% by mass or more. In addition, it should be 8.0% by mass or less, 7.0% by mass or less, 6.0% by mass or less, 5.0% by mass or less, 4.5% by mass or less, or 4.0% by mass or less. Can be done.

(Hydrophilic monomer)
As the hydrophilic monomer, at least one monomer selected from the following formulas 1 and 2 can be used.

a. Monomer of formula 1

In formula 1, R ¹ is represented by a hydrogen atom, a glyceryl group, a linear or branched hydroxyalkyl group having 1 to 4 carbon atoms, or-(C ₃ H ₆ O) _n H, where n is 2. It is a polypropylene glycol group which is an integer of about 10, and R ² is a hydrogen atom or a methyl group. Here, examples of the hydroxyalkyl group include 2-hydroxyethyl group, 2-hydroxypropyl group, 2-hydroxyethyl-2-methylpropyl group, 2-hydroxybutyl group, 3-hydroxybutyl group and 4-hydroxybutyl group. The group can be mentioned.

Specific examples of the hydrophilic monomer represented by the formula 1 include 2-hydroxyethyl (meth) acrylate, glyceryl (meth) acrylate, PPG-6 (meth) acrylate, and 2 (meth) acrylate. -Hydroxypropyl, (meth) acrylic acid 2-hydroxy-2-methylpropyl, (meth) acrylic acid can be mentioned. These can be used alone or in combination of two or more. Among them, glyceryl (meth) acrylate is preferable, and glyceryl methacrylate is more preferable, from the viewpoint of viscosity thickening, emulsion stability and the like.

b. Monomer of formula 2

In formula 2, R ³ is a hydrogen atom or a methyl group, and R ⁴ is a linear or branched alkyl group or hydroxyalkyl group having 1 to 4 carbon atoms, or a substitution of the following formula 3. It is a group.

Here, examples of the alkyl group in ^R4 include an ethyl group, a propyl group, an isopropyl group, and a butyl group, and examples of the hydroxyalkyl group include a 2-hydroxyethyl group and a 2-hydroxypropyl group. Examples thereof include 2-hydroxyethyl-2-methylpropyl group, 2-hydroxybutyl group, 3-hydroxybutyl group and 4-hydroxybutyl group.

Specific examples of the hydrophilic monomer represented by the formula 2 include N- (2-hydroxyethyl) (meth) acrylamide, N-isopropyl (meth) acrylamide, and 2- (meth) acrylamide-2-methylpropane. Sulfonic acid can be mentioned. These can be used alone or in combination of two or more. Of these, N- (2-hydroxyethyl) (meth) acrylamide is preferable, and N- (2-hydroxyethyl) acrylamide is more preferable, from the viewpoints of viscosity thickening, emulsion stability and the like.

(Hydrophobic monomer)
c. Monomer of formula 4

In formula 4, R ⁵ is a linear or branched alkyl group having 16 to 22 carbon atoms, and R ⁶ is a hydrogen atom or a methyl group. Here, examples of the linear or branched alkyl group having 16 to 22 carbon atoms include a cetyl group, a stearyl group, an isostearyl group, and a behenyl group. Among them, a linear alkyl group having 16 to 22 carbon atoms is preferable, and a cetyl group, a stearyl group, and a behenyl group are more preferable, from the viewpoints of thickening viscosity, emulsion stability, compatibility with polar oil, and the like.

Such a hydrophobic monomer is a (meth) acrylic acid alkyl ester, that is, an ester composed of (meth) acrylic acid and an alcohol having a linear or branched alkyl group having 16 to 22 carbon atoms. Specific examples thereof include cetyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, and behenyl (meth) acrylate. These can be used alone or in combination of two or more. Among them, cetyl (meth) acrylate, stearyl (meth) acrylate, and behenyl (meth) acrylate are preferable, and stearyl (meth) acrylate is preferable from the viewpoint of viscosity increase, emulsion stability, compatibility with polar oil, and the like. Is more preferable.

(Any monomer)
From the viewpoint of thickening and emulsion stability, the oil-soluble copolymer of the present disclosure preferably does not contain a monomer unit composed of monomers other than the above formulas 1, 2, and 4, but the present invention preferably contains. Other monomer units may be further contained as long as the effect is not impaired. The proportion of such monomer units can be 30 mol% or less, 20 mol% or less, 15 mol% or less, 10 mol% or less, or 5 mol% or less, and 0 mol% or less, based on the total amount of the constituent monomer units. It can be super 1 mol% or more, or 3 mol% or more.

Examples of the monomers other than the above formulas 1, 2, and 4 include one or more monomers selected from the group consisting of various anionic monomers, cationic monomers, nonionic monomers, and monomers other than these. ..

Specifically, examples of the hydrophilic monomer other than the hydrophilic monomer represented by the formula 1 or the formula 2 include vinylpyrrolidone, vinylimidazole, methoxypolyethylene glycol (meth) acrylate, and N, N-dimethyl (meth) acrylamide. , N, N-diethyl (meth) acrylamide, acryloylmorpholin, metaacryloylmorpholin, N- (2-methacryloyloxyethyl) ethyleneurea, 2-methacryloyloxyethylphosphorylcholine.

Examples of the hydrophobic monomer other than the hydrophobic monomer represented by the formula 4 include methylstyrene, styrene, benzyl (meth) acrylate, phenyl (meth) acrylate, tris (trimethylsiloxy) silylpropyl (meth) acrylate, and the like. (Meta) Acrylic acid-2-perfluorohexyl-2-ethyl can be mentioned.

In addition, a hydrophobic monomer represented by the following formula 5 can be used:

In the formula 5, R ⁷ is a branched alkyl group having 18 or less carbon atoms or a linear alkyl group having 12 or less carbon atoms, and R ⁸ is a hydrogen atom or a methyl group. Here, as the linear or branched alkyl group in R ⁷ , an alkyl group having 3 or more carbon atoms, 4 or more, 5 or more, 6 or more, 7 or more, or 8 or more can be used. Further, as ^R8 , a hydrogen atom is preferable.

The monomer unit composed of the hydrophobic monomer represented by the above formula 4 crystallizes by the hydrophobic monomer unit between the copolymers as the oil-soluble copolymers approach each other, so that the oil component is taken in. It is thought that the network structure is formed in the form. On the other hand, the monomer unit composed of the hydrophobic monomer represented by the formula 5 inhibits the crystallization by the monomer unit composed of the hydrophobic monomer represented by the formula 4, and suppresses the expression of the network structure based on the crystallization. Therefore, the thickening can be controlled by introducing a monomer unit composed of the hydrophobic monomer represented by the formula 5.

Specific examples of the hydrophobic monomer represented by the formula 5 include hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, and (meth). ) Decyl acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, isostearyl (meth) acrylate and the like can be mentioned. These can be used alone or in combination of two or more. Among them, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, lauryl (meth) acrylate, and isostearyl (meth) acrylate are preferable, and octyl (meth) acrylate, lauryl (meth) acrylate, Isostearyl (meth) acrylate is more preferred, and octyl (meth) acrylate and isostearyl (meth) acrylate are even more preferred.

(Method for producing oil-soluble copolymer)
The oil-soluble copolymer of the present disclosure can be obtained by a known polymerization method. The method is not limited to the following method, but for example, a mixture of a hydrophilic monomer and a hydrophobic monomer, a polymerization solvent, and a polymerization initiator are charged in a reaction vessel and maintained for several hours while being heated to maintain a constant temperature for polymerization. Proceed with the reaction. Then, the oil-soluble copolymer can be obtained by distilling off the polymerization solvent from the solution in the reaction vessel.

Further, a copolymer can also be obtained by a living radical polymerization method. In this case, the molecular weight of the copolymer can be easily adjusted, and a copolymer having a narrow molecular weight distribution can be produced.

d. Polymerization solvent As the polymerization solvent, a solvent that does not show reactivity with the functional group of the monomer is appropriately selected. Hydrocarbon solvents such as, but not limited to, n-hexane, n-octane, n-decane, isodecane, cyclohexane, methylcyclohexane, toluene, xylene, ethylbenzene, cumene; methanol, ethanol, n-propanol. , Isopropanol, n-butanol, isobutanol, n-hexanol, benzyl alcohol, cyclohexanol and other alcohol solvents; ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether, Hydroxyl-containing glycol ethers such as propylene glycol monoethyl ether, propylene glycol propyl ether, butyl carbitol, butyltriethylene glycol, and methyldipropylene glycol; , Glycol solvents such as diethylene glycol monobutyl ether acetate; ether solvents such as diethyl ether, dipropyl ether, methylcyclopropyl ether, tetrahydrofuran, dioxane, anisole; dimethylketone, diethylketone, ethylmethylketone, isobutylmethylketone, cyclohexanone, Ketone solvents such as isophorone and acetophenone; ester solvents such as methyl acetate, ethyl acetate, butyl acetate, propyl acetate, methyl butyrate, ethyl butyrate, caprolactone, methyl lactate, ethyl lactate; chloroform, dichloromethane, dichloroethane, o-dichlorobenzene Halogen-based solvents such as: formamide, N, N-dimethylformamide, N, N-dimethylacetamide, 2-pyrrolidone, N-methyl-2-pyrrolidone, ε-caprolactam and other amide-based solvents; dimethylsulfoxide, sulfolane, tetramethyl Examples thereof include urea, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, nitromethane, acetonitrile, nitrobenzene, dioctyl phthalate and the like. These can be used alone or in combination of two or more.

e. Polymerization Initiator As the polymerization initiator, conventionally known ones can be used, and the polymerization initiator is not particularly limited, and for example, an organic peroxide or an azo compound can be used. Specifically, benzoyl peroxide, dicumyl peroxide, diisopropyl peroxide, di-t-butylperoxide, t-butylperoxybenzoate, t-hexylperoxybenzoate, t-butylperoxy-2-ethylhexanoate. , T-hexylperoxy-2-ethylhexanoate, 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-bis (t-butyl) Peroxy) Hexil-3,3-isopropylhydroperoxide, t-butylhydroperoxide, dicumylhydroperoxide, acetylperoxide, bis (4-t-butylcyclohexyl) peroxydicarbonate, isobutyl peroxide, 3 , 3,5-trimethylhexanoyl peroxide, lauryl peroxide, 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) 3, 3,5-trimethylcyclohexane, 2,2'-azobis (isobutyronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (4-methoxy-2,4) -Dimethylvaleronitrile), dimethyl 2,2'-azobis (isobutyrate) and the like. These can be used alone or in combination of two or more.

f. Polymerization time The time for maintaining the reflux state, that is, the polymerization time is preferably continued until the monomer is exhausted, and is not particularly limited, but may be, for example, 1 hour or more, 2 hours or more, or 3 hours or more. Further, it can be 144 hours or less, 72 hours or less, or 48 hours or less.

g. Polymerization atmosphere The polymerization atmosphere is not particularly limited, and may be polymerized as it is in an atmospheric atmosphere, that is, oxygen may be present in the polymerization system within a normal range, and oxygen may be removed if necessary. Therefore, it may be carried out in an atmosphere of an inert gas such as nitrogen or argon. As the various materials to be used, impurities may be removed by distillation, activated carbon, alumina or the like, or commercially available products may be used as they are. Further, the polymerization may be carried out under light shielding, or may be carried out in a transparent container such as glass.

h. Other components that contribute to the polymerization reaction For example, in order to adjust the molecular weight of the copolymer, other components such as a chain transfer agent may be added to the reaction vessel as needed. The chain transfer agent is not particularly limited, and examples thereof include compounds having a mercapto group such as lauryl mercaptan and thioglycerol; inorganic salts such as sodium hypophosphite and sodium hydrogen sulfite; α-methylstyrene dimer and the like. .. The amount of the chain transfer agent to be used is appropriately determined so that the molecular weight of the copolymer is within the desired range, but is usually preferably in the range of 0.01 to 10% by mass with respect to the monomer.

《Water-in-oil emulsified cosmetics》
The water-in-oil emulsified cosmetic of the present disclosure contains the above-mentioned base and water droplets dispersed in the base and containing water.

The water-in-oil emulsified cosmetic of the present disclosure contains polar oil in addition to silicone oil as the oil component of the continuous phase, and contains water droplets of the dispersed phase and the oil-soluble copolymer described above, resulting in excellent thickening. The effect can be exhibited. To increase the viscosity of such cosmetics, a B-type viscometer (TVB type viscometer TVB-10, manufactured by Toki Sangyo Co., Ltd.) was used, and the rotor No. It can be evaluated by any of 2 to 4 and the viscosity measured under the measurement condition of the rotation speed of 12 rpm.

In some embodiments, for example, the unshaken viscosity or the post-shaking viscosity of the cosmetics of the present disclosure having a composition containing no powder such as a pigment is 500 mPa · s or more, 600 mPa · s or more, and the like. It is possible to achieve 700 mPa · s or more, 800 mPa · s or more, or 900 mPa · s or more. The upper limit of the viscosity is not particularly limited, but is, for example, 30,000 mPa · s or less, 15,000 mPa · s or less, 10,000 mPa · s or less, 5,000 mPa · s or less, or 3,000 mPa · s or less. Can be.

In some embodiments, for example, the unshaken viscosity or the post-shaking viscosity of the cosmetics of the present disclosure comprising powders such as pigments is 4,000 mPa · s or more, 5,000 mPa ·. It is possible to achieve s or more, 6,000 mPa · s or more, 7,000 mPa · s or more, 8,000 mPa · s or more, or 9,000 mPa · s or more. The upper limit of the viscosity is not particularly limited, but may be, for example, 60,000 mPa · s or less, 55,000 mPa · s or less, 50,000 mPa · s or less, or 45,000 mPa · s or less.

Here, the viscosity of the cosmetic is at least one of 1 day, 4 days, 2 weeks, and 4 weeks after the preparation of the cosmetic. Although the viscosity at the time point is intended, it is preferable to intend the viscosity 2 weeks or 4 weeks after the cosmetic is prepared from the viewpoint of the index of the thickening effect over a long period of time. In addition, the viscosity of the cosmetic after shaking is intended to be the viscosity when measured after shaking by hand several to several tens of times (for example, 3 to 20 times) so that the entire cosmetic is substantially uniform. ..

Conventional water-in-oil emulsified cosmetics containing silicone oil, prepared using organically modified clay minerals such as Benton, can exhibit a fresh feeling of use that causes the cosmetics to collapse at once when applied to the skin. On the other hand, in some embodiments, the water-in-oil emulsified cosmetic of the present disclosure has a new feeling of use, for example, creamy use, which is different from the case of using an organically modified clay mineral such as Benton. It is possible to express a feeling and a mellow feeling of use.

The water-in-oil emulsified cosmetic of the present disclosure contains the above-mentioned silicone oil, polar oil, and oil-soluble copolymer contained in the base. Here, regarding the blending ratios of the silicone oil, the polar oil, and the oil-soluble copolymer to the total amount of oil in the cosmetics, and the mass ratio of the silicone oil and the polar oil, the blending ratios of the above-mentioned bases and the blending ratios The mass ratio can be adopted as well.

On the other hand, the content of the silicone oil in the cosmetic may be 10% by mass or more, 15% by mass or more, 20% by mass or more, or 25% by mass or more, and 40% by mass or more, based on the total amount of the cosmetic. It can be mass% or less, 35 mass% or less, or 30 mass% or less.

The content of polar oil in the cosmetic may be 1.0% by mass or more, 3.0% by mass or more, or 5.0% by mass or more, and 20% by mass, based on the total amount of the cosmetic. % Or less, 15% by mass or less, or 10% by mass or less.

The content of the oil-soluble copolymer in the cosmetics is 0.1% by mass or more, 0.3% by mass or more, 0.5% by mass or more, 0.7% by mass or more, based on the total amount of the cosmetics. Alternatively, it can be 1.0% by mass or more, and can be 5.0% by mass or less, 4.0% by mass or less, 3.0% by mass or less, or 2.0% by mass or less. Since the water-in-oil emulsified cosmetic of the present disclosure may also exhibit a thickening effect based on the packing action of a plurality of water droplets contained in the cosmetic, the oil-soluble copolymer as a thickener is thus used. It is considered that the cosmetics of the present disclosure can exhibit excellent thickening even in a relatively low amount.

<Water drops>
The water-in-oil emulsified cosmetics of the present disclosure are prepared by adding water to the above-mentioned base, and as a result, such cosmetics contain water droplets as an aqueous phase or a dispersed phase.

(water)
The water that can be used in the water-in-oil emulsified cosmetics of the present disclosure is not particularly limited, but water used for cosmetics, quasi-drugs, and the like can be used. For example, purified water, ion-exchanged water, tap water and the like can be used.

The content of water can be 30% by mass or more, 35% by mass or more, 40% by mass or more, 45% by mass or more, 50% by mass or more, or 55% by mass or more with respect to the total amount of cosmetics. , 70% by mass or less, 65% by mass or less, or 60% by mass or less. As the water content increases, the number of water droplets can be increased, resulting in an increase in the cross-linking points of the network structure as shown in FIG. 2 (b) and the thickening effect based on the packing action of the water droplets. be able to. That is, an increase in the water content can contribute to an increase in the viscosity of the cosmetic.

(Surfactant)
In the water-in-oil emulsified cosmetics of the present disclosure, a surfactant is typically used at the time of preparation thereof. The surfactant is generally present mainly near the interface between the aqueous phase and the oil phase, that is, near the outer periphery of the water droplet, and a part of the surfactant is dispersed in the oil. Further, the surfactant may be blended in the above-mentioned base, or may be blended in an aqueous phase part containing water or the like.

The surfactant that can be used in the water-in-oil emulsified cosmetics of the present disclosure is not particularly limited, and known surfactants can be used alone or in combination of two or more. For example, silicone surfactants, in particular silicone surfactants modified with a polyether group or a polyglycerin group, can be used.

Examples of the silicone surfactant modified by the polyether group include PEG-11 methyl ether dimethicone, PEG-10 dimethicone, PEG-9 polydimethylsiloxyethyl dimethicone, lauryl PEG-9 polydimethylsiloxyethyl dimethicone, and cetyl PEG. / PPG-10 / 1 dimethicone and the like can be mentioned.

Examples of the silicone surfactant modified by the polyglycerin group include polyglyceryl-3 disiloxane dimethicone, polyglyceryl-3 polydimethylsiloxyethyl dimethicone, and lauryl polyglyceryl-3 polydimethylsiloxyethyl dimethicone.

The blending amount of the surfactant may be 0.1% by mass or more, 0.5% by mass or more, or 1.0% by mass or more with respect to the total amount of the cosmetics from the viewpoint of emulsion stability and the like. Further, it can be 8.0% by mass or less, 6.0% by mass or less, or 5.0% by mass or less.

<Arbitrary ingredient>
The water-in-oil emulsified cosmetic of the present disclosure may appropriately contain various components as long as it does not affect the effects of the present invention. Examples of various ingredients include additive ingredients that can be usually blended in cosmetics. For example, moisturizers such as dynamite glycerin, water-soluble polymers, film-forming agents such as siliconeized polysaccharides, metal ion blockers, lower alcohols, polyhydric alcohols (eg, 1,3-butylene glycol, PEG1500, dipropylene glycol). Etc.), higher fatty acids such as isostearic acid, various extracts, sugars, amino acids, organic amines, polymer emulsions, chelating agents, UV absorbers, pH regulators, skin nutrients, vitamins, pharmaceuticals, non-pharmaceutical products, cosmetics Water-soluble agents, antioxidants, buffers, preservatives such as phenyloxyethanol, antioxidant aids, slipperiness improvers, propellants, organic powders, pigments, dyes, pigments, fragrances, acid components, etc. Alkaline components and the like can be mentioned. These optional components can be used alone or in combination of two or more, and can be appropriately blended in the oil phase or the aqueous phase. Further, these optional components, particularly oil-soluble components or powder components such as pigments, may be previously blended in the above-mentioned base.

The cosmetics of the present disclosure may contain organically modified clay minerals such as Benton, but from the viewpoint of obtaining the above-mentioned novel feeling of use, such clay minerals are 1. It is preferably used in the range of 0% by mass or less, 0.5% by mass or less, less than 0.1% by mass, or 0.05% by mass or less, and more preferably no organically modified clay mineral is used.

<Use of water-based emulsified cosmetics in oil>
The product form of the water-in-oil emulsified cosmetic of the present disclosure is not particularly limited, but for example, skin care cosmetics such as milky lotion, cream, face oil, body oil, and beauty liquid; foundation, makeup base, etc. Makeup cosmetics such as lipstick, cheek red, eye shadow, mascara, and mascara base; skin cleaning agents such as makeup remover; hair cleaning agents; hair treatments, hair cosmetics such as hair oil; sunscreen cosmetics; hair dyes, etc. ..

The water-in-oil emulsified cosmetics of the present disclosure can improve the longevity of makeup by blending silicone oil, and can be blended with a specific oil-soluble copolymer and polar oil in oil containing silicone oil. In water-based emulsified cosmetics, it is possible to develop a new feeling of use that has never been seen before, for example, a creamy feeling of use, a mellow feeling of use, and the like. In addition, the water-in-oil emulsified cosmetic of the present disclosure can reduce or prevent problems such as separation (cracking) when a pigment is blended, for example. In consideration of these, it is advantageous to use the water-in-oil emulsified cosmetic of the present disclosure as a foundation containing a pigment and a novel feeling of use is desired among the above product forms.

<Manufacturing method of water-based emulsified cosmetics in oil>
The water-in-oil emulsified cosmetic of the present disclosure can be produced by a conventional method. For example, an oil-soluble copolymer and a surfactant can be added to an oil component and stirred to prepare a base, and water can be added to the base and stirred to obtain a water-in-oil emulsified cosmetic. If necessary, the above-mentioned optional components may be appropriately added to water or oil, or heating means may be applied.

For example, in the case of producing a water-in-oil emulsified cosmetic containing a powder component such as a foundation, an oil containing silicone oil and a polar oil is heated, and an oil-soluble copolymer and a surface activity thereof are heated therein. Mix the agents to prepare the oil phase parts. Next, the powder parts containing pigments and the like are mixed with the heated oil phase parts to prepare a base, and then the aqueous phase parts containing heated water and the like are mixed with the base and slowly cooled. Then, a water-in-oil emulsified cosmetic containing a powder component such as a pigment can be prepared.

Here, the heating temperature condition can be, for example, 70 ° C. or higher, 75 ° C. or higher, or 80 ° C. or higher, and can be 95 ° C. or lower, 90 ° C. or lower, or 85 ° C. or lower. .. The temperature condition for slow cooling can be, for example, 50 ° C. or lower, 45 ° C. or lower, or 40 ° C. or lower, and 25 ° C. or higher, 30 ° C. or higher, or 35 ° C. or higher.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. Hereinafter, unless otherwise specified, the blending amount is shown in% by mass.

<< Examples 1 to 16 and Comparative Examples 1 to 2 >>
<Synthesis of oil-soluble copolymer>
250 parts by mass of ethanol, 40 parts by mass of glyceryl methacrylate, which is a hydrophilic monomer, and a hydrophobic monomer in a 4-necked flask with a capacity of 1 liter equipped with a reflux condenser, a thermometer, a nitrogen gas introduction tube and a stirrer. 30 parts by mass of stearyl acrylate and 30 parts by mass of stearyl methacrylate were charged, and the temperature was raised under a nitrogen stream. When the reflux state was reached at about 80 ° C., 1 part by mass of 2,2'-azobisisobutyronitrile was added, and the reflux state was maintained for 4 hours to proceed with the polymerization reaction. Then, the solvent ethanol was distilled off from the solution in the flask to obtain an oil-soluble copolymer.

The viscosities of the water-in-oil emulsified cosmetics obtained by the formulations and manufacturing methods shown in Tables 1 and 2 below were evaluated. The results are summarized in Tables 1 and 2.

<Evaluation method 1>
(Evaluation of viscosity)
The viscosity of the cosmetic was determined by using a B-type viscometer (TVB type viscometer TVB-10, manufactured by Toki Sangyo Co., Ltd.) under an atmosphere of 25 ° C. It was evaluated under the measurement conditions of any of 2 to 4 and the rotation speed of 12 rpm. The viscosity of the cosmetic after shaking (shaking viscosity) was evaluated by the above viscometer and measurement conditions after shaking by hand about 10 times so that the entire cosmetic was substantially uniform.

In the cosmetics of Examples 1 and 2, the rotor was No. No. 4 was adopted, and in the cosmetics of Examples 3 to 4 and Comparative Examples 1 and 2, the rotor was No. No. 2 was adopted, and in the cosmetics of Examples 5 to 8, the rotor was No. 3 was adopted.

<Examples 1 to 4, Comparative Examples 1 to 2>
In Examples 1 to 4 and Comparative Examples 1 and 2, the presence or absence of an oil-soluble copolymer or polar oil and the influence of the type of silicone oil were evaluated. The results are shown in Table 1.

(Example 1)
An oil containing octylmethoxycinnamate and dimethylsilicone was heated to 80 to 90 ° C., PEG-10 dimethicone, an oil-soluble copolymer, and isostearic acid were added to the oil, and the mixture was stirred to prepare a base. .. While heating the base, water was added to the base and stirred, and then slowly cooled to 40 ° C. to prepare a water-in-oil emulsified cosmetic.

The base prepared in Example 1 was cloudy when heated, and when left at room temperature, a transparent gel-like substance was formed on the bottom. On the other hand, no gel-like substance was formed in the obtained water-in-oil emulsified cosmetic.

(Examples 2 to 4, Comparative Examples 1 to 2)
Cosmetics of Examples 2 to 4 and Comparative Examples 1 and 2 were prepared in the same manner as in Example 1 except that the blending ratios in Table 1 were changed.

The bases prepared in Examples 2 to 4 are all in a transparent state when heated, and when left at room temperature, the bases of Examples 3 and 4 are transparent at the bottom. A gel-like substance was formed. On the other hand, no gel-like substance was produced in any of the obtained water-in-oil emulsified cosmetics.

<result>
It was confirmed that all of the bases used in Examples 1 to 4 thickened with the addition of water. Further, comparing Examples 4 and Comparative Examples 1 and 2 using the same silicone oil, the cosmetics of Comparative Example 2 containing no polar oil contained an oil-soluble copolymer. No significant increase in viscosity was observed as compared with the viscosity of the cosmetic of Comparative Example 1 containing no oil-soluble copolymer. On the other hand, the viscosity of the cosmetic of Example 4 containing polar oil in addition to the oil-soluble copolymer was increased by 10 times or more as compared with the viscosity of the cosmetic of Comparative Example 1.

Further, as can be seen from Examples 1 to 4, it was confirmed that this effect of increasing the viscosity can occur in various silicone oils.

<Examples 5 to 8>
In Examples 5 to 8, the influence of the type of polar oil was evaluated. The results are shown in Table 2. Table 2 also shows the results of Example 4 and Comparative Examples 1 and 2.

(Examples 5 to 8)
The cosmetics of Examples 5 to 8 were prepared in the same manner as in Example 1 except that the blending ratios in Table 2 were changed.

Of the bases prepared in Examples 5 to 8, the bases of Examples 5 and 7 became cloudy at the time of heating, and the bases of Examples 6 and 8 were clouded at the time of heating. It was in a transparent state. Moreover, when these were left at room temperature, a transparent gel-like substance was formed on the bottom. On the other hand, no gel-like substance was produced in any of the obtained water-in-oil emulsified cosmetics.

<result>
It was confirmed that the bases used in Examples 5 to 8 also thickened with the addition of water. Comparing the cosmetics of Examples 4 to 8, as polar oils, octylmethoxycinnamate and diisostearyl malate having an IOB value of 0.28 and tripropylene glycol dipivalate having an IOB value of 0.52 were used. It was confirmed that the cosmetics of Examples 4, 5 and 7 using the above can stably produce a thickening effect over a long period of 2 weeks.

The cosmetics of Examples 6 and 8 using cetyl ethylhexanate having an IOB value of 0.13 and octyl salicylate having an IOB value of 0.60 had a reduced viscosity of unshaken after 2 weeks. However, it was found that when these cosmetics were shaken, the viscosity was remarkably restored. This tendency was also confirmed in the cosmetics of Examples 5 and 7. On the other hand, the cosmetic of Comparative Example 2 containing the oil-soluble copolymer but not the polar oil also recovers its viscosity to some extent by shaking, but its recovery performance is that of the cosmetics of Examples 5 to 8. It was inferior to the recovery performance. That is, the polar oil contributes to an increase in the viscosity of the water-in-oil emulsified cosmetic containing the silicone oil and the oil-soluble copolymer at the time of preparation, and when the viscosity of the cosmetic decreases over time, the polar oil contributes to the increase in viscosity. It was found that it has a function of recovering its viscosity by shaking.

<Examples 9 to 13>
The formulations of Examples 9 to 13 are formulations that can be used for foundations and the like containing pigments, and the influence of the blending ratio of the oil-soluble copolymer on the cosmetics of such formulations was evaluated. The results are shown in Table 3.

<Evaluation method 2>
(Evaluation of viscosity)
The viscosity of the cosmetic was determined by using a B-type viscometer (TVB type viscometer TVB-10, manufactured by Toki Sangyo Co., Ltd.) under an atmosphere of 25 ° C. It was evaluated under the measurement conditions of 2 to 4 and the rotation speed of 12 rpm.

(Evaluation of usability)
Each cosmetic was applied to the skin by a panel of 5 people, and the feeling of use and the lightness of the finger at the end of application were evaluated according to the following evaluation criteria:
A: Five respondents answered that they had a creamy feeling of use and that their fingers stopped lightly.
B: Four respondents answered that they had a creamy feeling of use and that their fingers stopped lightly.
C: Three respondents answered that they had a creamy feeling of use and that their fingers stopped lightly.
D: Two respondents answered that they had a creamy feeling of use and that their fingers stopped lightly.
E: 0-1 responded that they had a creamy feeling of use and that their fingers stopped lightly.

(Evaluation of pigment dispersibility)
Each cosmetic was applied to the skin by a panel of 5 specialists, and the dispersion state of the pigment in the cosmetic was evaluated according to the following criteria:
A: 4 to 5 respondents answered that the pigment was evenly dispersed without color floating.
B: Two or three respondents answered that the pigment was evenly dispersed without color floating.
C: 0 to 1 responded that the pigment was uniformly dispersed without color floating.

(Evaluation of stability over time)
The appearance of the cosmetics 4 weeks after preparation was visually observed, and the stability over time in the cosmetics was evaluated according to the following criteria:
A: No separation (cracking) occurred.
B: Separation (cracking) occurred slightly.
C: Separation (cracking) was clearly occurring.

(Example 9)
An oil containing octylmethoxycinnamate and dimethylsilicone is heated to 80 to 90 ° C., PEG-10 dimethicone, an oil-soluble copolymer, and isostearic acid are added to the oil, and the mixture is stirred to prepare an oil phase part. did. While heating the oil phase parts, each component of the powder parts shown in Table 3 was added and stirred to prepare a base. While heating the base, water was added to the base and stirred, and then slowly cooled to 40 ° C. to prepare a water-in-oil emulsified cosmetic containing a pigment.

(Examples 10 to 13)
The cosmetics of Examples 10 to 13 were prepared in the same manner as in Example 9 except that the blending ratios in Table 3 were changed.

<result>
It was confirmed that the pigment-containing bases used in Examples 9 to 13 also thickened with the addition of water. Further, as is clear from Table 3, it was confirmed that as the blending amount of the oil-soluble copolymer increased, the viscosity of the cosmetic, especially the viscosity after the day of preparation, also increased. In addition, considering the usability of cosmetics, in the case of water-in-oil emulsified cosmetics containing pigments, the oil-soluble copolymer should be blended in an amount of more than 0.6% by mass based on the total cosmetics. Turned out to be advantageous.

The viscosities of the cosmetics of Examples 9 to 13 are significantly higher than the viscosities of the cosmetics of Examples 1 to 8, which is considered to be influenced by the blending of the pigment.

<Examples 14 to 16>
The formulations of Examples 14 to 16 are also formulations that can be used for foundations and the like containing pigments, and the effects of silicone oil and polar oil on cosmetics of such formulations were evaluated. The results are shown in Table 4. Table 4 also shows the results of Example 11.

<Evaluation method 3>
(Evaluation of viscosity)
The viscosity of the cosmetic was determined by using a B-type viscometer (TVB type viscometer TVB-10, manufactured by Toki Sangyo Co., Ltd.) under an atmosphere of 25 ° C. It was evaluated under the measurement conditions of 2 to 4 and the rotation speed of 12 rpm.

(Evaluation of stability over time)
The appearance of the cosmetics 4 weeks after preparation was visually observed, and the stability of the cosmetics over time was evaluated according to the following criteria:
A: No separation (cracking) occurred.
B: Separation (cracking) occurred slightly.
C: Separation (cracking) was clearly occurring.

(Examples 14 to 16)
The cosmetics of Examples 14 to 16 were prepared in the same manner as in Example 9 except that the blending ratios in Table 4 were changed.

<result>
It was confirmed that the pigment-containing bases used in Examples 14 to 16 also thickened with the addition of water. Further, as is clear from Table 4, it was confirmed that when the ratio of the polar oil in the oil content increased, the viscosity of the cosmetic also increased.

It was also confirmed that in the case of water-in-oil emulsified cosmetics containing pigments, the proportion of polar oil in the oil content could affect the separation (cracking) of the cosmetics. Therefore, in the case of such cosmetics, it was found that the separation (cracking) of the cosmetics can be reduced or prevented by adjusting the mass ratio of the silicone oil and the polar oil.

10, 20 Base for water-in-oil emulsified cosmetics 11, 21 Oil-soluble copolymer 13,23 Water droplets 15, 25 Water-in-oil emulsified cosmetics

Claims (15)

Silicone oil,
Polar oil, as well as
An oil-soluble copolymer having a monomer unit composed of at least one hydrophilic monomer selected from the following formulas 1 and 2 and a monomer unit composed of the hydrophobic monomer of the following formula 4.
including,
Water-in-oil emulsified cosmetic base:

In Equation 1,
R ¹ is represented by a hydrogen atom, a glyceryl group, a linear or branched hydroxyalkyl group having 1 to 4 carbon atoms, or-(C _{3H 6} O) _n H, where n is an integer of 2 to 10. Is a polypropylene glycol group, and ^R2 is a hydrogen atom or a methyl group.

In formula 2,
R ³ is a hydrogen atom or a methyl group, and R ⁴ is a linear or branched alkyl group or hydroxyalkyl group having 1 to 4 carbon atoms, or a substituent of the following formula 3.

In formula 4,
R ⁵ is a linear or branched alkyl group having 16 to 22 carbon atoms, and R ⁶ is a hydrogen atom or a methyl group. The monomer of the formula 1 is 2-hydroxyethyl (meth) acrylate, glyceryl (meth) acrylate, PPG-6 (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate. At least one selected from hydroxy-2-methylpropyl and (meth) acrylic acid, and the monomer of the formula 2 is N- (2-hydroxyethyl) (meth) acrylamide, N-isopropyl (meth). The base according to claim 1, which is at least one selected from acrylamide and 2- (meth) acrylamide-2-methylpropanesulfonic acid. The base according to claim 1 or 2, wherein the monomer of the formula 4 is at least one selected from cetyl (meth) acrylate, stearyl (meth) acrylate, and behenyl (meth) acrylate. In the oil-soluble copolymer, the monomer unit of the hydrophilic monomer is contained in the range of 30 to 50 mol%, and the monomer unit of the hydrophobic monomer is contained in the range of 50 to 70 mol%. The base according to any one of claims 1 to 3. The base according to any one of claims 1 to 4, wherein the silicone oil is at least one selected from dimethyl silicone, methyl phenyl polysiloxane, and cyclic polysiloxane. The base according to any one of claims 1 to 5, wherein the polar oil is a polar oil having an IOB value of 0.10 or more. The base according to claim 6, wherein the polar oil is at least one selected from octylmethoxycinnamate, tripropylene glycol dipivalate, cetyl ethylcaproate, diisostearyl malate, and octyl salicylate. The base according to any one of claims 1 to 7, wherein the silicone oil is contained in an amount of 50% by mass or more. The base according to any one of claims 1 to 8, wherein the mass ratio of the silicone oil to the polar oil is 9: 1 to 4: 1. The base according to any one of claims 1 to 9, which thickens when water is added. The base according to any one of claims 1 to 10 and
Water droplets dispersed in the base and containing water,
including,
Water-in-oil emulsified cosmetics. The cosmetic according to claim 11, wherein the content of the oil-soluble copolymer is 0.1% by mass or more. The cosmetic according to claim 11 or 12, wherein the content of the silicone oil is 10% by mass or more. The cosmetic according to any one of claims 11 to 13, further comprising a pigment. The cosmetic according to claim 14, which is used as a foundation.

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