JP7381163B2 - Emulsifying composition, its production method, evaluation method and design method, and polymer emulsifier - Google Patents

Description

Applicable to Article 30, Paragraph 2 of the Patent Act Published in Journal of Oleo Science, 2017 Oct 1; 66 (10): 1121-1128

The present invention relates to an emulsion composition in which a polyvinyl polymer is adsorbed on the emulsion interface.

An emulsified composition in which an oil phase component and an aqueous phase component are mixed together using an emulsifier is widely used as a dosage form for cosmetics. However, common low-molecular-weight emulsifiers may cause problems such as skin irritation and stickiness.
In order to solve such problems, various emulsification techniques using polymeric emulsifiers have been proposed in recent years.

Patent Document 1 discloses an emulsified composition using hydroxyethyl cellulose as an emulsifier.
Further, Patent Document 2 discloses an emulsified composition using an alkyl-modified carboxyvinyl polymer as an emulsifier.

Japanese Patent Application Publication No. 2011-231049 Japanese Patent Application Publication No. 09-019631

Although the polymer emulsifiers mentioned above have advantages such as being less irritating to the skin and less sticky when contained in low concentrations, they have inferior emulsifying power compared to conventional low-molecular emulsifiers. . Therefore, in order to ensure the stability of the emulsified state, it is necessary to incorporate a high amount of a polymer emulsifier in the emulsified composition to make it highly viscous, resulting in a problem of stickiness.

In addition, when an emulsified composition is applied, the water phase components or emulsifier are exposed on most of the surface of the coating film, so even if the oil contained in the oil phase has a good feel, it is difficult to feel it. There was an issue.

In view of this situation, it is an object of the present invention to provide a novel emulsified composition emulsified with a polymeric emulsifier, which has excellent emulsion stability, is less sticky, and exhibits the original feel of an oil agent contained in an oil phase. The task is to

The present invention, which solves the above problems, is an emulsion composition characterized in that a polyvinyl polymer satisfying the following conditions (A) and (B) is adsorbed on an emulsion interface.

(A) Forms fine particles when dispersed in water.
(B) A cross-sectional image of a coating film of an emulsion containing the polyvinyl polymer obtained by the method shown in (i) satisfies the condition (ii).
(i) An oil-in-water emulsion containing the polyvinyl polymer, Calcein, and NileRed is applied onto a slide glass, and the coated film is dried at 35° C. for 2 hours. The coated film after drying is observed with a confocal laser scanning microscope, and a plurality of Z-stack images are acquired in the thickness direction of the coated film to obtain a cross-sectional image of the coated film.
(ii) More than 90% of the surface layer of the cross section of the coating film is occupied by a phase that emits fluorescence derived from NileRed.

In a preferred embodiment of the present invention, the fine particles made of the polyvinyl polymer are adsorbed on the emulsion interface.
Such an emulsion composition has more excellent emulsion stability and usability.

The emulsion composition of the present invention has excellent emulsion stability, is less sticky, and exhibits the feel of an oil agent contained in the oil phase.

A preferred form of the present invention is characterized in that the cross-sectional image of the coating film of the emulsion containing the polyvinyl polymer obtained by the method shown in (i) above further satisfies the condition (iii).
(iii) A fluorescent phase derived from Calcein is in contact with the glass slide.

A preferred form of the present invention is characterized in that the cross-sectional image of the coating film of the emulsion containing the polyvinyl polymer obtained by the method shown in (i) above further satisfies the condition (iv).
(iv) A phase that emits fluorescence derived from Calcein exhibits a form in which striated structures extending in the vertical direction are arranged in parallel.

A preferred embodiment of the present invention is characterized in that the polyvinyl polymer has a hydrophobic side chain.
A polyvinyl polymer having a hydrophobic side chain can provide an emulsified composition that is less sticky.

In a preferred embodiment of the present invention, the hydrophobic side chain is a saturated or unsaturated hydrocarbon chain that may have a branched chain and/or a cyclic structure.
An emulsion composition in which a polyvinyl polymer having a hydrocarbon chain is adsorbed on the emulsion interface has better emulsion stability.

A preferred embodiment of the present invention is characterized in that the hydrophobic side chain is a hydrocarbon group having 6 to 30 carbon atoms or an acyl group.
According to the polyvinyl polymer having such a hydrophobic side chain, it is possible to provide an emulsion composition with more excellent emulsion stability.

A preferred embodiment of the present invention is characterized in that the polyvinyl polymer does not have an ionizable group.
An emulsion composition in which a polyvinyl polymer having no ionizable groups is adsorbed on the emulsion interface has excellent emulsion stability while being less sticky.

In a preferred embodiment of the present invention, the polyvinyl polymer has one or more types derived from vinyl monomers represented by the following general formula (I), (II), or (III). It is characterized by including units.

（一般式（Ｉ）において、Ａは－Ｏ－又は－ＣＯＯ－を表し、Ｒ^１は水素原子または炭素数１～３のアルキル基を表し、Ｒ^２は炭素数６～３０の炭化水素基を表す。） General formula (I)

(In general formula (I), A represents -O- or -COO-, R ¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R ² represents a hydrocarbon group having 6 to 30 carbon atoms. represent.)

（一般式（ＩＩ）において、Ａは－Ｏ－又は－ＣＯＯ－を表し、Ｒ^３は水素原子または炭素数１～３のアルキル基を表し、Ｒ^４，Ｒ^５は同一でも異なっていてもよく、炭素数６～２２のアシル基を表す。Ｘは三価のアルコールからＯＨ基が脱離した基を表す。） General formula (II)

(In general formula (II), A represents -O- or -COO-, R ³ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R ⁴ and R ⁵ may be the same or different. , represents an acyl group having 6 to 22 carbon atoms. X represents a group in which an OH group is removed from a trivalent alcohol.)

（一般式（ＩＩＩ）において、Ａは－Ｏ－又は－ＣＯＯ－を表し、Ｒ^６は水素原子または炭素数１～３のアルキル基を表し、Ｒ^７、Ｒ^８、Ｒ^９は同一でも異なっていてもよく、炭素数６～２２のアシル基を表す。Ｙは四価アルコールからＯＨ基が脱離した基を表す。） General formula (III)

(In general formula (III), A represents -O- or -COO-, R ⁶ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R ⁷ , R ⁸ and R ⁹ are the same or different. may represent an acyl group having 6 to 22 carbon atoms.Y represents a group obtained by removing an OH group from a tetrahydric alcohol.)

In a preferred embodiment of the present invention, the polyvinyl polymer is a polymerizable carboxylic acid, a vinyl monomer represented by the following general formula (VIII), or a vinyl monomer represented by the following general formula (IX). , one or more types derived from vinyl monomers selected from vinyl monomers represented by the following general formula (X) or vinyl monomers represented by the following general formula (XI) It is characterized by containing the constituent units of.

（一般式（ＶＩＩＩ）中、Ｂは－Ｏ－又は－ＣＯＯ－を表し、Ｒ^１３は水素原子または炭素数１～３のアルキル基を表し、Ｒ^１４は水酸基を有していてもよい炭素数２～４のアルキレン基を表し、Ｒ^１５は水素原子、炭素数６～１０の芳香族炭化水素基、炭素数１～１４の脂肪族炭化水素基又は炭素数１～１２のアシル基を表す。ｎは６～４０の整数を表す。） General formula (VIII)

(In general formula (VIII), B represents -O- or -COO-, R ¹³ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R ¹⁴ has a carbon number that may have a hydroxyl group. It represents an alkylene group having 2 to 4 carbon atoms, and R ¹⁵ represents a hydrogen atom, an aromatic hydrocarbon group having 6 to 10 carbon atoms, an aliphatic hydrocarbon group having 1 to 14 carbon atoms, or an acyl group having 1 to 12 carbon atoms. n represents an integer from 6 to 40.)

（一般式（ＩＸ）中、ＢはＢは－Ｏ－又は－ＣＯＯ－を表し、Ｒ^１６は水素原子またはメチル基をあらわす。） General formula (IX)

(In general formula (IX), B represents -O- or -COO-, and R ¹⁶ represents a hydrogen atom or a methyl group.)

（一般式（Ｘ）中、Ｄは－ＣＯ－又は置換基が無いことを表し、Ｒ^１７は水素原子またはメチル基を、Ｇ－Ｏ－は還元糖の１位の水酸基より水素を除いた基を表す。ｍは２又は３を、ｌは１～５の整数を表す。） General formula (X)

(In the general formula (X), D represents -CO- or the absence of a substituent, ^R17 represents a hydrogen atom or a methyl group, and G-O- represents a group obtained by removing hydrogen from the hydroxyl group at the 1st position of a reducing sugar. (m represents 2 or 3, l represents an integer from 1 to 5.)

（一般式（ＸＩ）中Ｒ^１８は水素原子またはメチル基を、Ｒ^１９はアミノ酸残基、ポリアミン残基又はアミノアルコール残基を表す。Ｑは酸素原子又はＮＨで表される基を表す。） General formula (XI)

(In general formula (XI), R ¹⁸ represents a hydrogen atom or a methyl group, R ¹⁹ represents an amino acid residue, a polyamine residue, or an amino alcohol residue. Q represents an oxygen atom or a group represented by NH.)

The present invention also relates to a method for producing the emulsified composition described above. That is, the production method of the present invention includes a step of preparing an aqueous phase in which the polyvinyl polymer is dispersed in an aqueous phase to form fine particles made of the polyvinyl polymer, and an oil phase is added to the aqueous phase in which the fine particles are dispersed. It is characterized by including an emulsification step of adding phase components and stirring and mixing.

According to the production method of the present invention, an emulsion composition with excellent emulsion stability can be produced.

In addition, when the emulsified composition contains an electrolyte and/or a polymer that does not satisfy the conditions of (A) and (B) above, in the aqueous phase preparation step, the emulsion composition contains an electrolyte and/or a polymer that does not satisfy the conditions of (A) and (B) above. After dispersing the polyvinyl polymer in an aqueous phase that does not contain a polymer that does not satisfy the condition of B) to form fine particles made of the polyvinyl polymer, an electrolyte and/or the above (A) is added to the aqueous phase. It is also preferable to add a polymer that does not satisfy the above condition (B).
By performing the step of micronizing the polyvinyl polymer in the aqueous phase in the absence of an electrolyte and/or a polymer that does not satisfy the conditions (A) and (B) above, the emulsion can be made more stable. It is possible to produce an emulsified composition with excellent properties and usability.

The present invention also relates to an emulsified composition produced by the above-described production method of the preferred embodiment of the present invention. Emulsified compositions in this form have excellent emulsion stability and feel when used.

The present invention also provides a method for evaluating an emulsified composition in which a polymer is adsorbed at the emulsion interface, and when 90% or more of the surface layer of a dry coating film of the emulsified composition is occupied by an oil phase. , it also relates to a method for evaluating an emulsified composition, characterized in that the feel is determined to be similar to that of an oil agent contained in the oil phase of the emulsified composition.

According to this evaluation method, the feeling of use of the emulsion composition can be evaluated without using a sensory test.

A preferred embodiment of the present invention is characterized in that when the aqueous phase is in contact with the coated surface in the dry coating film, it is determined that the feel is closer to that of the oil agent contained in the oil phase of the emulsified composition.

The present invention also relates to a method for designing emulsified compositions. That is, the present invention includes the steps of selecting a polymer with emulsifying effect;
Observe the dry coating film of the emulsified composition emulsified with the polymer selected in the first selection step, and if 90% or more of the surface layer is occupied by the oil phase, select the polymer as the polymer emulsifier. 1. A method for designing an emulsion composition, comprising: a second selection step.
According to the method for designing an emulsified composition of the present invention, it is possible to design an emulsified composition that has a feel similar to that of an oil agent.

The present invention also relates to a polymer emulsifier made of a polyvinyl polymer that satisfies the following conditions (A) and (B).
(A) Forms fine particles when dispersed in water.
(B) A cross-sectional image of a coating film of an emulsion containing the polyvinyl polymer obtained by the method shown in (i) satisfies the condition (ii).
(i) An oil-in-water emulsion containing the polyvinyl polymer, Calcein, and NileRed is applied onto a slide glass, and the coated film is dried at 35° C. for 2 hours. The coated film after drying is observed with a confocal laser scanning microscope, and a plurality of Z-stack images are acquired in the thickness direction of the coated film to obtain a cross-sectional image of the coated film.
(ii) More than 90% of the surface layer of the cross section of the coating film is occupied by a phase that emits fluorescence derived from NileRed.

By using a polyvinyl polymer emulsifier that satisfies these conditions, it is possible to provide an emulsified composition that has excellent emulsion stability, is less sticky, and exhibits the feel of an oil agent contained in the oil phase.

According to the present invention, it is possible to provide an emulsified composition emulsified with a polymer emulsifier that has low stickiness and excellent emulsion stability. Furthermore, it is possible to provide an emulsified composition that exhibits the feel of an oil agent contained in the oil phase.

1 shows an electron microscope image of an emulsion interface of oil droplets dispersed in an emulsion composition of an example. The upper row is a cross-sectional image of the dry coating film of the emulsified composition of Example 1, and the lower row is a schematic diagram thereof. The upper row is a cross-sectional image of the dried coating film of the emulsified composition of Comparative Example 1, and the lower row is a schematic diagram thereof. The upper row is a cross-sectional image of the dry coating film of the emulsified composition of Comparative Example 2, and the lower row is a schematic diagram thereof. The upper row is a cross-sectional image of the dry coating film of the emulsified composition of Comparative Example 3, and the lower row is a schematic diagram thereof. It is a figure showing the measurement result of MIU and MMU of the dry coating film of an emulsified composition.

<Emulsifying composition>
The present invention is an emulsion composition in which a polyvinyl polymer satisfying the conditions (A) and (B) described below is adsorbed on the emulsion interface.

In the present invention, it is preferable that the fine particles made of the polyvinyl polymer (hereinafter also referred to as polyvinyl polymer fine particles) are adsorbed on the emulsion interface.

Here, "fine particles made of a polyvinyl polymer" refers to fine particles formed exclusively by association in a solution, and does not include those formed into solid particles before being added to the solution.

The average particle diameter of the polyvinyl polymer fine particles adsorbed on the emulsion interface is not particularly limited, but is preferably 1 nm to 1000 nm, more preferably 5 to 500 nm, even more preferably 10 to 200 nm, even more preferably 15 to 100 nm. The wavelength is 100 nm, more preferably 15 to 50 nm, even more preferably 20 to 30 nm.

The fine particle-forming polyvinyl polymer satisfies conditions (A) and (B). Each condition will be explained in detail below.

(A) Forms fine particles when dispersed in water.
The fine particle-forming polyvinyl polymer forms fine particles when dispersed in water. The average particle diameter of the fine particles is not particularly limited, but is preferably 1 nm to 1000 nm, more preferably 5 to 500 nm, even more preferably 10 to 200 nm, even more preferably 15 to 100 nm, still more preferably 15 to 50 nm, and even more preferably It is 20 to 30 nm.

Note that the average particle diameter of the fine particles when dispersed in water can be measured using a dynamic light scattering measurement method using Zetasizer Nano-Z ZEN3600 and Malvern Co. (laser Doppler method) as the basic principle.

Further, the average particle size of the fine particles when dispersed in water can be estimated to be the average particle size of the fine polymer particles in a state where they are adsorbed on the emulsion interface.

Since the polyvinyl polymer used in the present invention has the condition (A), that is, the property of forming fine particles when dispersed in water, it may also be referred to as a fine particle-forming polyvinyl polymer in this specification. .

(B) A cross-sectional image of a coating film of an emulsion containing the polyvinyl polymer obtained by the method shown in (i) satisfies the condition (ii).
Condition (B) requires that the polyvinyl polymer has the property of detaching from the emulsion interface and having a demulsifying effect after the emulsion composition is applied and the water evaporates. .

In order to determine whether the polyvinyl polymer satisfies condition (B), a cross-sectional image of the emulsion coating film is obtained by the method shown in (i).
That is, (i) an oil-in-water emulsion containing the polyvinyl polymer, Calcein, and NileRed is applied onto a slide glass, and the applied film is dried at 35° C. for 2 hours. The coated film after drying is observed with a confocal laser scanning microscope, and a plurality of Z-stack images are acquired in the thickness direction of the coated film to obtain a cross-sectional image of the coated film.

In (i), the method for preparing the oil-in-water emulsion is not particularly limited. Preferably, it is prepared by dispersing the polyvinyl polymer in an aqueous phase to form fine particles, adding the oil phase, and stirring and mixing.

Any electrolyte and/or polymer that does not satisfy the conditions (A) and (B) above may be added to this oil-in-water emulsion. In that case, the polyvinyl polymer is dispersed in an aqueous phase that does not contain an electrolyte and/or a polymer that does not satisfy the conditions (A) and (B) above, to form fine particles, and then added to the aqueous phase. It is preferable to prepare the aqueous phase by adding an electrolyte and/or a polymer that does not satisfy the conditions (A) and (B) above.

When Calcein and NileRed are incorporated into an emulsion, they are localized in the aqueous and oil phases, respectively. When preparing an oil-in-water emulsion, it is preferable to dissolve Calcein in the water phase and dissolve NileRed in the oil phase, and then mix the water phase and the oil phase.

The prepared oil-in-water emulsion is then applied to a glass slide. The method of application is not particularly limited, and it is preferable to use an applicator such as a doctor blade.

After coating, the slide glass is placed in a 35°C environment for 2 hours to dry the coated film. As a result, the water in the aqueous phase, which was the continuous phase of the oil-in-water emulsion, evaporates. The behavior of the aqueous and oil phases after the water has evaporated, resulting from the properties of the polyvinyl polymer, is important in the present invention. The behavior of this water phase and oil phase is observed using a microscope.

The coated film after drying is observed using a confocal laser scanning microscope. Confocal laser scanning microscopes can pick up only signals from the focal plane and exclude signals generated from other sources, and can generate high-resolution, clear two-dimensional images from the fluorescence obtained by scanning a sample in the focal plane. It is possible to generate dimensional images. The two-dimensional images captured by shifting the focal plane little by little are then reconstructed (Z-stack) to generate a three-dimensional image (Z-stack image), which makes it possible to obtain a cross-sectional image of the sample. .

In (i), with the function of this confocal laser scanning microscope, the dried coating film is observed with a confocal laser scanning microscope, multiple Z-stack images are acquired in the thickness direction of the coating film, and a cross-section of the coating film is obtained. Get the image.

In the cross-sectional image of the coating film thus obtained, the surface layer of the cross-section of the coating film is accounted for at least 90%, more preferably at least 95%, and still more preferably at least 99% by a phase that emits fluorescence derived from NileRed, that is, an oil phase. If so, it is determined that the polyvinyl polymer satisfies condition (ii).

Since condition (ii) is determined based on the cross-sectional image of the coating film, there is no need to observe the surface layer by looking at the plane in the spreading direction of the coating film (XY plane). If a phase that emits fluorescence derived from NileRed is observed to be in contact with 90% or more of the upper base in the cross section of the coating film, it is determined that the polyvinyl polymer satisfies condition (ii).

In the present invention, it is preferable that the cross-sectional image of the coating film satisfies condition (iii) in addition to condition (ii).
(iii) A fluorescent phase derived from Calcein is in contact with the glass slide.

In other words, if a phase that emits fluorescence derived from NileRed is observed to be in contact with the bottom of the cross section of the coating film, it is determined that the polypolymer satisfies condition (iii).

Furthermore, it is preferable that the cross-sectional image of the coating film satisfies the condition (iv) in addition to the condition (ii).
(iv) A phase that emits fluorescence derived from Calcein exhibits a form in which striated structures extending in the vertical direction are arranged in parallel.

In other words, if the phase that emits fluorescence derived from Calcein forms a plurality of striated patterns extending in the vertical direction in the cross section of the coating film, it is determined that the polyvinyl polymer satisfies condition (iv). .
The width of each filament does not need to be uniform, and may be a spine-like structure that narrows from the bottom to the top (see the schematic diagram at the bottom of FIG. 2).

At this time, preferably 90% or more, more preferably 95% or more, still more preferably 99% or more, still more preferably 100% or more of all the striated structures appearing in the cross-sectional image are formed on the slide glass, that is, coated Preferably, it is in contact with the bottom of the cross section of the membrane.

It is preferable that the fine particle-forming polyvinyl polymer further satisfies the following condition (C).
(C) The viscosity of an aqueous solution containing a polyvinyl polymer at a concentration of 0.5% by mass at 25° C. and 1 atm is 3000 mPa·S or less.

The viscosity of the aqueous solution containing the fine particle-forming polyvinyl polymer at a concentration of 0.5% by mass at 25° C. and 1 atmosphere is preferably 2500 mPa·S or less, and even more preferably 2000 mPa·S or less.

Further, it is preferable that the fine particle-forming polyvinyl polymer satisfies the following condition (D).
(D) The fine particle-forming polyvinyl polymer does not exhibit a concentration-dependent thickening effect when made into an aqueous solution with a concentration of 0.1% by mass to 1.0% by mass.

In particular, in the above concentration range, a fine particle-forming polyvinyl polymer is used such that the viscosity of the aqueous solution at 25° C. and 1 atm is 3000 mPa·S or less, more preferably 2500 mPa·S or less, and even more preferably 2000 mPa·S or less. It is preferable.

An emulsified composition containing a fine particle-forming polyvinyl polymer having such viscosity characteristics does not easily become sticky.
Note that the viscosity can be measured at 25° C. and 1 atm using a standard method (for example, a B-type viscometer (DIGITAL VISMETRON VDA: manufactured by Shibaura System Co., Ltd.).

Note that the polyvinyl polymer refers to a polymer having the following basic structure 2, which is obtained by polymerizing a vinyl monomer having the following basic structure 1.

基本構造１

基本構造２
（ａ～ｄの置換基は特に限定されない）

Basic structure 1

Basic structure 2
(Substituents a to d are not particularly limited)

The fine particle-forming polyvinyl polymer only needs to form fine particles that are adsorbed to the emulsion interface and satisfy the conditions (A) and (B) above, and the structure of the main chain skeleton is not limited.
Preferred examples of the fine particle-forming polyvinyl polymer include polyolefin polymers, polyacrylic polymers, polyacrylamide polymers, and polystyrene polymers. In particular, a polyacrylic polymer can be preferably exemplified as the fine particle-forming polyvinyl polymer.

The fine particle-forming polyvinyl polymer preferably has a hydrophobic side chain. Examples of hydrophobic side chains include hydrocarbon chains and perfluoroalkyl chains, with hydrocarbon chains being preferred.

The lower limit of the number of carbon atoms in the hydrocarbon chain is not particularly limited, but is preferably 3 or more, more preferably 4 or more, still more preferably 5 or more, even more preferably 6 or more.
The upper limit of the number of carbon atoms in the hydrocarbon chain is also not particularly limited, but is preferably 50 or less, more preferably 40 or less, and even more preferably 30 or less.
The hydrocarbon chain may be branched or linear.

The hydrocarbon chain may be saturated or unsaturated, but is preferably saturated.

More specific examples of the hydrocarbon chain include a branched hydrocarbon group having 13 to 30 carbon atoms and a hydrocarbon group having 6 to 12 carbon atoms having two or more branches.

Moreover, although the hydrocarbon chain may have a ring structure, it is more preferable that the hydrocarbon chain does not contain a ring structure.

More specifically, the hydrocarbon chain includes a branched hydrocarbon group having 13 to 30 carbon atoms that does not contain a ring structure, and a hydrocarbon group having 6 to 12 carbon atoms that does not contain a ring structure and has two or more branches. can be exemplified.

Examples of branched hydrocarbon groups containing no ring structure having 13 to 30 carbon atoms include 1-methyldodecanyl group, 11-methyldodecanyl group, 3-ethylundecanyl group, 3-ethyl-4,5,6 -trimethyloctyl group, 1-methyltridecanyl group, 1-hexyloctyl group, 2-butyldecanyl group, 2-hexyloctyl group, 4-ethyl-1-isobutyloctyl group, 1-methylpentadecanyl group, 2- hexyldecanyl group, 2-octyldecanyl group, 2-hexyldodecanyl group, 16-methylheptadecanyl group, 9-methylheptadecanyl group, 7-methyl-2-(3-methylhexyl)decanyl group, Examples include 3,7,11,15-tetra-methylhexadecanyl group, 2-octyldodecanyl group, 2-decyltetradecanyl group, and 2-dodecylhexadecanyl group.

Examples of hydrocarbon groups having 6 to 12 carbon atoms and having two or more branches that do not contain a ring structure include 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, 3,3-dimethylbutyl group, 1, 3-dimethylbutyl group, 1,2,2-trimethylpropyl group, 1,1-dimethylpentanyl group, 1-isopropylbutyl group, 1-isopropyl-2-methylpropyl group, 1,1-diethylpropyl group, 1 -Ethyl-1-isopropylpropyl group, 2-ethyl-4-methylpentyl group, 1-propyl-2,2-dimethylpropyl group, 1,1,2-trimethyl-pentyl group, 1-isopropyl-3-methylbutyl group , 1,2-dimethyl-1-ethylbutyl group, 1,3-dimethyl-1-ethylbutyl group, 1-ethyl-1-isopropyl-propyl group, 1,1-dimethylhexyl group, 1-methyl-1-ethylpentyl group group, 1-methyl-1-propylbutyl group, 1,4-dimethylhexyl group, 1-ethyl-3-methylpentyl group, 1,5-dimethylhexyl group, 1-ethyl-6-methylheptyl group, 1, 1,3,3-tetramethylbutyl group, 1,2-dimethyl-1-isopropylpropyl group, 3-methyl-1-(2,2-dimethylethyl)butyl group, 1-isopropylhexyl group, 3.5. 5-trimethylhexyl group, 2-isopropyl-5-methylhexyl group, 1,5-dimethyl-1-ethylhexyl group, 3,7-dimethyloctyl group, 2,4,5-trimethylheptyl group, 2,4,6 Examples include -trimethylheptyl group, 3,5-dimethyl-1-(2,2-dimethylethyl)hexyl group, and the like.

Further, as described above, a hydrocarbon chain is preferably exemplified as a hydrophobic side chain, but a polyvinyl polymer containing a hydrocarbon chain in the form of an acyl group is also preferable.

The lower limit of the number of carbon atoms in the acyl group is not particularly limited, but is preferably 3 or more, more preferably 4 or more, still more preferably 5 or more, even more preferably 6 or more.
The upper limit of the number of carbon atoms in the acyl group is also not particularly limited, but is preferably 50 or less, more preferably 40 or less, still more preferably 30 or less, and even more preferably 22 or less.

The acyl group may be linear or branched.

The acyl group may contain or have a cyclic structure.

Examples of the branched acyl group having 6 to 22 carbon atoms that do not contain a ring structure include 2-methylpentanoyl group, 3-methylpentanoyl group, 4-methylpentanoyl group, 2-ethylbutanoyl group, 2-methylpentanoyl group, Ethylbutanoyl group, 2,2-dimethylbutanoyl group, 3,3-dimethylbutanoyl group, 2-methylhexanoyl group, 4-methylhexanoyl group, 5-methylhexanoyl group, 2,2-dimethylpentayl group Noyl group, 4,4-dimethylpentanoyl group, 2-methylheptanoyl group, 2-ethylhexyl group, 2-propylpentanoyl group, 2,2-dimethylhexanoyl group, 2,2,3-trimethylpentanoyl group , 2-methyloctanoyl group, 3,3,5-trimethylhexanoyl group, 2-methylnonanoyl group, 4-methylnonanoyl group, 8-methylnonanoyl group, 4-ethyloctanoyl group, 2-ethyloctanoyl group, 2- Butylhexanoyl group, 2-tert-butylhexanoyl group, 2,2-diethylhexanoyl group, 2,2-dimethyloctanoyl group, 3,7-dimethyloctanoyl group, neodecanoyl group, 7-methyldecanoyl group , 2-methyl-2-ethyloctanoyl group, 2-methylundecanoyl group, 10-methylundecanoyl group, 2,2 dimethyldecanoyl group, 2-ethyldecanoyl group, 2-butyloctanoyl group, diethyloctanoyl group, 2-tert-butyl-2,2,4-trimethylpentanoyl group, 10-methyldodecanoyl group, 3-methyldodecanoyl group, 4-methyldodecanoyl group, 11-methyldodecanoyl group, 10-ethylundecanoyl group, 12-methyltridecanoyl group, 2-butyldecanoyl group, 2-hexyloctanoyl group, 2-butyl-2-ethyloctanoyl group, 12-methyltetradecanoyl group, 14 -Methylpentadecanoyl group, 2-butyldodecanoyl group, 2-hexyldecanoyl group, 16-methylheptadecanoyl group, 2,2-dimethylhexanoyl group, 2-butylhexadecanoyl group, 2-hexyldodecanoyl group Noyl group, 2,4,10,14-tetramethylpentanoyl group, 18-methylnonadecanoyl group, 3,7,11,15-tetra-methylhexadecanoyl group, 19-methyleicosanoyl group, etc. I can give an example.

In a preferred form, examples of the hydrophobic side chain include a branched acyl group having 10 to 22 carbon atoms, or an acyl group having 6 to 9 carbon atoms having two or more branches.

The branched acyl group having 10 to 22 carbon atoms or the acyl group having 6 to 9 carbon atoms having two or more branches preferably does not contain a cyclic structure.

Examples of the branched acyl group having 10 to 22 carbon atoms that do not contain a ring structure include 2-methylnonanoyl group, 4-methylnonanoyl group, 8-methylnonanoyl group, 4-ethyloctanoyl group, 2-ethyloctanoyl group, 2-methylnonanoyl group, -butylhexanoyl group, 2-tert-butylhexanoyl group, 2,2-diethylhexanoyl group), 2,2-dimethyloctanoyl group, 3,7-dimethyloctanoyl group, neodecanoyl group), 7-methyl Decanoyl group, 2-methyl-2-ethyloctanoyl group, 2-methylundecanoyl group, 10-methylundecanoyl group, 2,2 dimethyldecanoyl group, 2-ethyldecanoyl group, 2-butylocta Noyl group, diethyloctanoyl group, 2-tert-butyl-2,2,4-trimethylpentanoyl group, 10-methyldodecanoyl group, 3-methyldodecanoyl group, 4-methyldodecanoyl group, 11-methyldodecanoyl group Noyl group, 10-ethylundecanoyl group, 12-methyltridecanoyl group, 2-butyldecanoyl group, 2-hexyloctanoyl group, 2-butyl-2-ethyloctanoyl group, 12-methyltetradecanoyl group group, 14-methylpentadecanoyl group, 2-butyldodecanoyl group, 2-hexyldecanoyl group, 16-methylheptadecanoyl group, 2,2-dimethylhexanoyl group, 2-butylhexadecanoyl group, 2 -hexyldodecanoyl group, 2,4,10,14-tetramethylpentanoyl group, 18-methylnonadecanoyl group, 3,7,11,15-tetra-methylhexadecanoyl group, 19-methyleicosanoyl group Examples include groups.

Examples of the acyl group having 6 to 9 carbon atoms and having two or more branches that do not contain a ring structure include 2,2-dimethylbutanoyl group, 3,3-dimethylbutanoyl group, and 2,2-dimethylpentanoyl group. , 4,4-dimethylpentanoyl group, 2,2-dimethylhexanoyl group, 2,2,3-trimethylpentanoyl group, 3,5,5-trimethylhexanoyl group, and the like.

The fine particle-forming polyvinyl polymer may include one or more structural units derived from vinyl monomers represented by the following general formulas (I), (II), or (III) (hereinafter simply , sometimes referred to as "structural unit I", etc.) can be preferably exemplified.

General formula (I)

In the general formula (I), A represents -O- or -COO-, R ¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R ² represents a hydrocarbon group having 6 to 30 carbon atoms. represent.

Here, examples of the alkyl group represented by R ¹ include methyl group, ethyl group, propyl group, isopropyl group, and cyclopropyl group. In the present invention, R ¹ is preferably a hydrogen atom or a methyl group.

R ² may be branched or linear.
More specifically, R ² can be exemplified by a branched hydrocarbon group having 13 to 30 carbon atoms and a hydrocarbon group having 6 to 12 carbon atoms having two or more branches.

Although R ² may have a ring structure, it is more preferable that it does not contain a ring structure.

The hydrocarbon group for R ² may be saturated or unsaturated, but is preferably saturated.

R ² is preferably a branched hydrocarbon group having 13 to 30 carbon atoms and not containing a ring structure, or a hydrocarbon group having 6 to 12 carbon atoms and having two or more branches and not containing a ring structure.

Examples of branched hydrocarbon groups containing no ring structure having 13 to 30 carbon atoms include 1-methyldodecanyl group, 11-methyldodecanyl group, 3-ethylundecanyl group, 3-ethyl-4,5,6 -trimethyloctyl group, 1-methyltridecanyl group, 1-hexyloctyl group, 2-butyldecanyl group, 2-hexyloctyl group, 4-ethyl-1-isobutyloctyl group, 1-methylpentadecanyl group, 2- hexyldecanyl group, 2-octyldecanyl group, 2-hexyldodecanyl group, 16-methylheptadecanyl group, 9-methylheptadecanyl group, 7-methyl-2-(3-methylhexyl)decanyl group, Examples include 3,7,11,15-tetra-methylhexadecanyl group, 2-octyldodecanyl group, 2-decyltetradecanyl group, and 2-dodecylhexadecanyl group.

Examples of hydrocarbon groups having 6 to 12 carbon atoms and having two or more branches that do not contain a ring structure include 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, 3,3-dimethylbutyl group, 1, 3-dimethylbutyl group, 1,2,2-trimethylpropyl group, 1,1-dimethylpentanyl group, 1-isopropylbutyl group, 1-isopropyl-2-methylpropyl group, 1,1-diethylpropyl group, 1 -Ethyl-1-isopropylpropyl group, 2-ethyl-4-methylpentyl group, 1-propyl-2,2-dimethylpropyl group, 1,1,2-trimethyl-pentyl group, 1-isopropyl-3-methylbutyl group , 1,2-dimethyl-1-ethylbutyl group, 1,3-dimethyl-1-ethylbutyl group, 1-ethyl-1-isopropyl-propyl group, 1,1-dimethylhexyl group, 1-methyl-1-ethylpentyl group group, 1-methyl-1-propylbutyl group, 1,4-dimethylhexyl group, 1-ethyl-3-methylpentyl group, 1,5-dimethylhexyl group, 1-ethyl-6-methylheptyl group, 1, 1,3,3-tetramethylbutyl group, 1,2-dimethyl-1-isopropylpropyl group, 3-methyl-1-(2,2-dimethylethyl)butyl group, 1-isopropylhexyl group, 3.5. 5-trimethylhexyl group, 2-isopropyl-5-methylhexyl group, 1,5-dimethyl-1-ethylhexyl group, 3,7-dimethyloctyl group, 2,4,5-trimethylheptyl group, 2,4,6 Examples include -trimethylheptyl group, 3,5-dimethyl-1-(2,2-dimethylethyl)hexyl group, and the like.

General formula (II)

General formula (III)

In the general formulas (II) and (III), A represents -O- or -COO-, R ³ and R ⁶ represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ⁴ , R ⁵ , R ⁷ , R ⁸ and R ⁹ may be the same or different and represent an acyl group having 6 to 22 carbon atoms. X represents a group obtained by removing an OH group from a trihydric alcohol. Y represents a group obtained by removing an OH group from a tetrahydric alcohol.

Here, examples of the alkyl group represented by R ³ and R ⁶ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a cyclopropyl group, and the like. In the present invention, R ³ and R ⁶ are preferably a hydrogen atom or a methyl group, particularly preferably a methyl group.

The number of carbon atoms in the acyl groups of R ⁴ , R ⁵ , R ⁷ , R ⁸ , and R ⁹ in general formulas (II) and (III) is 12 to 22, more preferably 14 to 20, and still more preferably 16 to 20. .

The acyl groups of R ⁴ , R ⁵ , R ⁷ , R ⁸ , and R ⁹ in general formulas (II) and (III) may be branched or linear, but are preferably branched. It is.

Further, when R ⁴ , R ⁵ , R ⁷ , R ⁸ , and R ⁹ in general formulas (II) and (III) are branched acyl groups, the number of carbon atoms in the main chain is preferably 9 to 21, More preferably 12-20, still more preferably 16-18.

Furthermore, when R ⁴ , R ⁵ , R ⁷ , R ⁸ , and R ⁹ in general formulas (II) and (III) are branched acyl groups, the number of branches is preferably 1 to 3, more preferably 1 or 2, more preferably 1.

Furthermore, when R ⁴ , R ⁵ , R ⁷ , R ⁸ , and R ⁹ in general formulas (II) and (III) are branched acyl groups, the carbon position number of the main chain to which the branch is bonded The larger the value, the better. Specifically, the branched chain is preferably bonded to the 1st to 3rd carbon, more preferably the 1st or 2nd carbon, and even more preferably the 1st carbon from the carbon at the end of the main chain. It is preferable.

The acyl groups of R ⁴ , R ⁵ , R ⁷ , R ⁸ and R ⁹ may contain a cyclic structure, but preferably do not contain a cyclic structure.

The hydrocarbon chain portions of the acyl groups of R ⁴ , R ⁵ , R ⁷ , R ⁸ and R ⁹ may be saturated or unsaturated, but are preferably saturated.

In addition, examples of the branched acyl group having 6 to 22 carbon atoms and not containing a ring structure represented by R ⁴ , R ⁵ , R ⁷ , R ⁸ , and R ⁹ include 2-methylpentanoyl group, 3-methyl Pentanoyl group, 4-methylpentanoyl group, 2-ethylbutanoyl group, 2-ethylbutanoyl group, 2,2-dimethylbutanoyl group, 3,3-dimethylbutanoyl group, 2-methylhexanoyl group, 4-methylhexanoyl group, 5-methylhexanoyl group, 2,2-dimethylpentanoyl group, 4,4-dimethylpentanoyl group, 2-methylheptanoyl group, 2-ethylhexyl group, 2-propylpentanoyl group , 2,2-dimethylhexanoyl group, 2,2,3-trimethylpentanoyl group, 2-methyloctanoyl group, 3,3,5-trimethylhexanoyl group, 2-methylnonanoyl group, 4-methylnonanoyl group, 8 -Methylnonanoyl group, 4-ethyloctanoyl group, 2-ethyloctanoyl group, 2-butylhexanoyl group, 2-tert-butylhexanoyl group, 2,2-diethylhexanoyl group, 2,2-dimethyloctanoyl group group, 3,7-dimethyloctanoyl group, neodecanoyl group, 7-methyldecanoyl group, 2-methyl-2-ethyloctanoyl group, 2-methylundecanoyl group, 10-methylundecanoyl group, 2, 2 dimethyldecanoyl group, 2-ethyldecanoyl group, 2-butyloctanoyl group, diethyloctanoyl group, 2-tert-butyl-2,2,4-trimethylpentanoyl group, 10-methyldodecanoyl group, 3 -methyldodecanoyl group, 4-methyldodecanoyl group, 11-methyldodecanoyl group, 10-ethylundecanoyl group, 12-methyltridecanoyl group, 2-butyldecanoyl group, 2-hexyloctanoyl group, 2-butyl-2-ethyl octanoyl group, 12-methyltetradecanoyl group, 14-methylpentadecanoyl group, 2-butyldodecanoyl group, 2-hexyldecanoyl group, 16-methylheptadecanoyl group, 2 , 2-dimethylhexanoyl group, 2-butylhexadecanoyl group, 2-hexyldodecanoyl group, 2,4,10,14-tetramethylpentanoyl group, 18-methylnonadecanoyl group, 3,7,11 , 15-tetra-methylhexadecanoyl group, 19-methyleicosanoyl group, and the like.

Furthermore, in a preferred embodiment of the present invention, in general formulas (II) and (III), R ⁴ , R ⁵ , R ⁷ , R ⁸ , and R ⁹ may be the same or different, and each of the branched carbon atoms It is an acyl group having 10 to 22 carbon atoms, or an acyl group having 6 to 9 carbon atoms and having two or more branches.
In this case, although it may contain a cyclic structure, it is preferable that it does not contain a cyclic structure.

In such a preferred embodiment, the branched acyl group having 10 to 22 carbon atoms and not containing a ring structure represented by R ⁴ , R ⁵ , R ⁷ , R ⁸ , and R ⁹ is 2- Methylnonanoyl group, 4-methylnonanoyl group, 8-methylnonanoyl group, 4-ethyloctanoyl group, 2-ethyloctanoyl group, 2-butylhexanoyl group, 2-tert-butylhexanoyl group, 2,2-diethylhexanoyl group group), 2,2-dimethyloctanoyl group, 3,7-dimethyloctanoyl group, neodecanoyl group), 7-methyldecanoyl group, 2-methyl-2-ethyloctanoyl group, 2-methylundecanoyl group , 10-methylundecanoyl group, 2,2 dimethyldecanoyl group, 2-ethyldecanoyl group, 2-butyloctanoyl group, diethyloctanoyl group, 2-tert-butyl-2,2,4-trimethylpenta Noyl group, 10-methyldodecanoyl group, 3-methyldodecanoyl group, 4-methyldodecanoyl group, 11-methyldodecanoyl group, 10-ethylundecanoyl group, 12-methyltridecanoyl group, 2-butyl group Decanoyl group, 2-hexyl octanoyl group, 2-butyl-2-ethyl octanoyl group, 12-methyltetradecanoyl group, 14-methylpentadecanoyl group, 2-butyldodecanoyl group, 2-hexyldecanoyl group group, 16-methylheptadecanoyl group, 2,2-dimethylhexanoyl group, 2-butylhexadecanoyl group, 2-hexyldodecanoyl group, 2,4,10,14-tetramethylpentanoyl group, 18- Examples include methylnonadecanoyl group, 3,7,11,15-tetra-methylhexadecanoyl group, and 19-methyleicosanoyl group.

Furthermore, in a preferred embodiment, the acyl group having 6 to 9 carbon atoms and having two or more branches and not containing a ring structure, represented by R ⁴ , R ⁵ , R ⁷ , R ⁸ , and R ⁹ , includes: 2,2-dimethylbutanoyl group, 3,3-dimethylbutanoyl group, 2,2-dimethylpentanoyl group, 4,4-dimethylpentanoyl group, 2,2-dimethylhexanoyl group, 2,2,3 Examples include -trimethylpentanoyl group and 3,5,5-trimethylhexanoyl group.

The group derived from a trihydric alcohol, represented by A preferred example is a group in which an OH group is removed from a trihydric alcohol selected from the group consisting of:

In addition, the group derived from a tetrahydric alcohol represented by Y in general formula (III) is not particularly limited as long as it is a group in which an OH group is removed from a tetrahydric alcohol, but diglycerin, pentaerythritol, erythritol A suitable example is a group in which an OH group is removed from a tetrahydric alcohol selected from the group consisting of , D-threitol, and L-threitol.

In the present invention, it is particularly preferable to use a polyvinyl polymer containing structural unit II as the fine particle-forming polyvinyl polymer.

The fine particle-forming polyvinyl polymer preferably has a hydrophilic side chain.
Hydrophilic side chains include hydrophilic functional groups such as carboxyl groups, hydroxyl groups, and amino groups, or side chains containing such groups, and bonds such as -O-, -NH-, -SO ₂ -, -CO-NH-, etc. An example is a polymerizable side chain having repeating.

Examples of the hydrophilic side chain include substituents represented by general formulas (IV) to (VII) shown below.

（一般式（ＩＶ）中Ｒ^１０は水酸基を有していてもよい炭素数２～４のアルキレン基を表し、Ｒ^１１は水素原子、炭素数６～１０の芳香族炭化水素基、炭素数１～１４の脂肪族炭化水素基又は炭素数１～１２のアシル基を表す。ｎは６～４０の整数を表す。） General formula (IV)

(In the general formula (IV), R ¹⁰ represents an alkylene group having 2 to 4 carbon atoms which may have a hydroxyl group, and R ¹¹ is a hydrogen atom, an aromatic hydrocarbon group having 6 to 10 carbon atoms, and 1 carbon atom. ~14 aliphatic hydrocarbon group or an acyl group having 1 to 12 carbon atoms. n represents an integer of 6 to 40.)

Furthermore, examples of the alkylene group represented by ^R10 include ethylene group, propylene group, isopropylene group, 2-hydroxypropylene group, 1-hydroxy-2-methylethylene group, and 2-hydroxy-1-methylethylene group. For example, among these, ethylene group or propylene group is preferable, and ethylene group is more preferable.

Further, among the groups represented by R ¹¹ , examples of aromatic groups having 6 to 10 carbon atoms include phenyl group, benzyl group, methylphenyl group, ethylphenyl group; aliphatic groups having 1 to 14 carbon atoms; Preferred examples of the hydrocarbon group include methyl group, ethyl group, butyl group, tert-butyl group, hexyl group, cyclohexyl group, octyl group, 2-ethylhexyl group, lauryl group; carbon number 1 Preferred examples of the 12 acyl groups include a formyl group, an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a valeryl group, and a lauroyl group. Among these, the group represented by R ¹¹ is preferably an aliphatic hydrocarbon group having 1 to 14 carbon atoms, and more preferably an alkyl group having 1 to 12 carbon atoms.

Furthermore, n in general formula (IV) is in the numerical range of 6 to 40.

General formula (V)

（一般式（ＶＩ）中Ｇ－Ｏ－は還元糖の１位の水酸基より水素を除いた基を表す。ｍは２又は３を、ｌは１～５の整数を表す。） General formula (VI)

(G-O- in general formula (VI) represents a group obtained by removing hydrogen from the 1-position hydroxyl group of a reducing sugar. m represents 2 or 3, and l represents an integer from 1 to 5.)

In the substituent represented by general formula (VI), the reducing sugar represented by G--O- is a group in which hydrogen is removed from the hydroxyl group at the 1-position of the reducing sugar, specifically, glucose, mannose, galactose, etc. , monosaccharides such as arabinose, xylose, and ribose; disaccharides such as maltose, lactose, and cellobiose; trisaccharides such as maltotriose; and oligosaccharides such as maltooligosaccharides. Among these, one or more selected from the group consisting of glucose, galactose, arabinose, xylose, ribose, maltose, lactose and cellobiose are preferred, and glucose is particularly preferred.

（一般式（ＶＩＩ）中Ｒ^１２はアミノ酸残基、ポリアミン残基又はアミノアルコール残基を表す。Ｑは酸素原子又はＮＨで表される基を表す。） General formula (VII)

(R ¹² in general formula (VII) represents an amino acid residue, a polyamine residue, or an aminoalcohol residue. Q represents an oxygen atom or a group represented by NH.)

In the substituent of general formula (VII), the amino acid of the amino acid residue represented by ^R12 is not particularly limited as long as it is a commonly known amino acid, and specifically, glycine, alanine, glutamine, Examples include lysine and arginine. Among these, lysine residues are particularly preferred because the resulting fine particle-forming polyvinyl polymer has an excellent skin barrier recovery effect.

In addition, the polyamine in the polyamine residue represented by ^R12 means an amine having two or more amino groups which may be substituted with an alkyl group in the same molecule, and specifically includes diamine, triamine, Examples include tetraamine and amines in which the hydrogen atom of these amino groups is substituted with an alkyl group. Among these, diamines are preferable because the resulting skin external preparation containing the fine particle-forming polyvinyl polymer has a particularly excellent usability. Examples include ethylenediamine, 1,4-diamino-n-butane, and 1,6-diamino-n-hexane.

Furthermore, the amino alcohol in the amino alcohol residue represented by R ¹² means a compound having an amino group which may be substituted with an alkyl group and an alcoholic hydroxyl group in the same molecule. The amino alcohol is not particularly limited as long as it is commonly known, but specific examples include ethanolamine, triethylaminoethanol, and the like.

The salt of the substituent represented by general formula (VII) is not particularly limited, but specifically includes sodium salt, potassium salt, ammonium salt, amine salt, etc. in which the acid moiety is neutralized with a base; , hydrochloride, sulfate, nitrate, phosphate, citrate, oxalate, carbonate, etc., in which the amino group moiety is neutralized with acid.

Specific examples of the substituent represented by general formula (VII) and its salts include those having the following structures and salts thereof.

As mentioned above, the fine particle-forming polyvinyl polymer only needs to form fine particles adsorbed to the emulsion interface and satisfy the conditions (A) and (B) above, and the main clavicle to which the above-mentioned hydrophilic side chains are bonded. The case structure is not limited.

The fine particle-forming polyvinyl polymer may have a structural unit derived from a polymerizable carboxylic acid or a salt thereof. Specific examples of the polymerizable carboxylic acid or its salt include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid, and its sodium salt, potassium salt, ammonium salt, and amine salt. Among these, acrylic acid, methacrylic acid and salts thereof are particularly preferred because of their high polymerizability. When introducing a constituent unit derived from a salt of a polymerizable carboxylic acid into a fine particle-forming polyvinyl polymer, the polymerizable carboxylic acid may be converted into a salt in advance and the polymerization reaction may be carried out. After a structural unit derived from a carboxylic acid is induced into a fine particle-forming polyvinyl polymer, it may be neutralized with a base to form a salt.

Further, as the fine particle-forming polyvinyl polymer, a polyvinyl polymer containing one or more types of structural units derived from vinyl monomers represented by the following general formulas (VIII) to (XI) is used. can be exemplified preferably.

General formula (VIII)

In the general formula (VIII), B represents -O- or -COO-, R ¹³ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R ¹⁴ represents a carbon number that may have a hydroxyl group. It represents an alkylene group having 2 to 4 carbon atoms, and R ¹⁵ represents a hydrogen atom, an aromatic hydrocarbon group having 6 to 10 carbon atoms, an aliphatic hydrocarbon group having 1 to 14 carbon atoms, or an acyl group having 1 to 12 carbon atoms. n represents an integer from 6 to 40.

In the general formula (VIII), B represents -O- or -COO-, particularly preferably -COO-. In other words, it is preferable to take the form of an acrylic monomer.

Examples of the alkyl group represented by R ¹³ in the general formula (VIII) include a methyl group, an ethyl group, a propyl group, an isopropyl group, and a cyclopropyl group. In the present invention, R ¹³ is preferably a hydrogen atom or a methyl group.

Furthermore, examples of the alkylene group represented by ^R14 include ethylene group, propylene group, isopropylene group, 2-hydroxypropylene group, 1-hydroxy-2-methylethylene group, and 2-hydroxy-1-methylethylene group. For example, among these, ethylene group or propylene group is preferable, and ethylene group is more preferable.

Further, among the groups represented by R ¹⁵ , examples of aromatic groups having 6 to 10 carbon atoms include phenyl group, benzyl group, methylphenyl group, ethylphenyl group; aliphatic groups having 1 to 14 carbon atoms; Preferred examples of the hydrocarbon group include methyl group, ethyl group, butyl group, tert-butyl group, hexyl group, cyclohexyl group, octyl group, 2-ethylhexyl group, lauryl group; carbon number 1 Preferred examples of the 12 acyl groups include a formyl group, an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a valeryl group, and a lauroyl group. Among these, the group represented by R ¹⁵ is preferably an aliphatic hydrocarbon group having 1 to 14 carbon atoms, and more preferably an alkyl group having 1 to 12 carbon atoms.

Furthermore, n in general formula (VIII) is in the numerical range of 6 to 40.

Among the monomers represented by the general formula (VIII), specific examples of monomers in which R ¹⁴ is a propylene group include polypropylene glycol (9) monoacrylate, polypropylene glycol (13) monoacrylate, and polypropylene glycol (9) monoacrylate. Examples include methacrylate, polypropylene glycol (13) monomethacrylate, and the like. Note that the number in parentheses represents n. Many of these polymers are commercially available. Specific examples of these commercially available products include the trade names "Blenmar" AP-400, AP-550, AP-800, PP-500, and PP-800 (all manufactured by NOF Corporation).

Among the monomers represented by the general formula (VIII), specific examples of monomers in which R ¹⁴ is an ethylene group include polyethylene glycol (10) monoacrylate, polyethylene glycol (8) monomethacrylate, and polyethylene glycol (23) monomer. Acrylate, polyethylene glycol (23) Monomethacrylate, methoxypolyethylene glycol (9) Acrylate, methoxypolyethylene glycol (9) Methacrylate, methoxypolyethylene glycol (23) Methacrylate, oleyloxypolyethylene glycol (18) Methacrylate, lauroxypolyethylene glycol (18) Examples include acrylate, lauroyloxypolyethylene glycol (10) methacrylate, stearoxypolyethylene glycol (30) monomethacrylate, and the like.

The above-mentioned acrylic monomer can be obtained in high yield by an esterification reaction between the corresponding polyethylene glycol, polyethylene glycol monoether, or polyethylene glycol monoester and the chloride or anhydride of acrylic acid or methacrylic acid. Moreover, since there are already many commercially available products, it is also possible to use such commercially available products. Examples of such commercially available products are Blenmar, AE-400, PE-350, AME-400, PME-400, PME-1000, ALE-800, PSE-1300, etc. Co., Ltd.) etc. can be exemplified.

General formula (IX)

(In general formula (IX), B represents -O- or -COO-, and R ¹⁶ represents a hydrogen atom or a methyl group.)

In the general formula (IX), B represents -O- or -COO-, particularly preferably -COO-. In other words, it is preferable to take the form of an acrylic monomer.

Specific examples of the acrylic monomer represented by the general formula (IX) include 2-acryloyloxyethylphosphorylcholine (APC) and 2-methacryloyloxyethylphosphorylcholine (MPC). These monomers are described, for example, in Polymer Journal, Vol. 22, No. It can be synthesized by the following method described in 5.
<Synthesis method>
2-bromoethylphosphoryl dichloride and 2-hydroxyethyl methacrylate or 2-hydroxyethyl acrylate are reacted to produce 2-methacryloyloxyethyl-2'-bromoethyl phosphate or 2-acryloyloxyethyl-2'-bromoethyl phosphate. After obtaining these compounds, these compounds and triethylamine are reacted in methanol.

（一般式（Ｘ）中、Ｄは－ＣＯ－又は置換基が無いことを表し、Ｒ^１７は水素原子またはメチル基を、Ｇ－Ｏ－は還元糖の１位の水酸基より水素を除いた基を表す。ｍは２又は３を、ｌは１～５の整数を表す。） General formula (X)

(In the general formula (X), D represents -CO- or the absence of a substituent, ^R17 represents a hydrogen atom or a methyl group, and G-O- represents a group obtained by removing hydrogen from the hydroxyl group at the 1st position of a reducing sugar. (m represents 2 or 3, l represents an integer from 1 to 5.)

In the general formula (X), D represents -CO- or the absence of a substituent, and is particularly preferably -CO-. In other words, it is preferable to take the form of an acrylic monomer.

In the hydrophilic monomer represented by the general formula (X), the reducing sugar represented by G-O- is a group in which hydrogen is removed from the hydroxyl group at the 1st position of the reducing sugar, specifically, glucose, mannose, Examples include one or more selected from the group consisting of monosaccharides such as galactose, arabinose, xylose, and ribose, disaccharides such as maltose, lactose, and cellobiose, trisaccharides such as maltotriose, and oligosaccharides such as maltooligosaccharides. Among them, one or more selected from the group consisting of glucose, galactose, arabinose, xylose, ribose, maltose, lactose and cellobiose are preferred, and glucose is particularly preferred. Further, as the monomer represented by the general formula (X), glucosyloxyethyl methacrylate (hereinafter abbreviated as GEMA) or glucosyloxyethyl acrylate (hereinafter abbreviated as GEA) is preferable.

（一般式（ＸＩ）中Ｒ^１８は水素原子またはメチル基を、Ｒ^１９はアミノ酸残基、ポリアミン残基又はアミノアルコール残基を表す。Ｑは酸素原子又はＮＨで表される基を表す。） General formula (XI)

(In general formula (XI), R ¹⁸ represents a hydrogen atom or a methyl group, R ¹⁹ represents an amino acid residue, a polyamine residue, or an amino alcohol residue. Q represents an oxygen atom or a group represented by NH.)

In the general formula (XI), D represents -CO- or the absence of a substituent, and is particularly preferably -CO-. In other words, it is preferable to take the form of an acrylic monomer.

In the monomer of general formula (XI), the amino acid of the amino acid residue represented by ^R19 is not particularly limited as long as it is a commonly known amino acid, and specifically, glycine, alanine, glutamine, lysine, etc. , arginine, etc. Among these, lysine residues are particularly preferred because the resulting fine particle-forming polyvinyl polymer has an excellent skin barrier recovery effect.

In addition, the polyamine in the polyamine residue represented by ^R19 means an amine having two or more amino groups which may be substituted with an alkyl group in the same molecule, and specifically includes diamine, triamine, Examples include tetraamine and amines in which the hydrogen atom of these amino groups is substituted with an alkyl group. Among these, diamines are preferable because the resulting skin external preparation containing the fine particle-forming polyvinyl polymer has a particularly excellent usability. Examples include ethylenediamine, 1,4-diamino-n-butane, and 1,6-diamino-n-hexane.

Furthermore, the amino alcohol in the amino alcohol residue represented by R ¹⁹ means a compound having an amino group which may be substituted with an alkyl group and an alcoholic hydroxyl group in the same molecule. The amino alcohol is not particularly limited as long as it is commonly known, but specific examples include ethanolamine, triethylaminoethanol, and the like.

Salts of the monomer represented by general formula (XI) are not particularly limited, but specifically include sodium salts, potassium salts, ammonium salts, amine salts, etc. in which the acid moiety is neutralized with a base; Further, examples include hydrochloride, sulfate, nitrate, phosphate, citrate, oxalate, carbonate, etc. in which the amino group moiety is neutralized with acid. When introducing a constituent unit derived from a salt of a monomer represented by general formula (XI) into a fine particle-forming polyvinyl polymer, the monomer represented by general formula (XI) is converted into a salt in advance, A polymerization reaction may be carried out, or a structural unit derived from a monomer represented by general formula (XI) may be induced into a fine particle-forming polyvinyl polymer by a polymerization reaction, and then neutralized to form a salt. It's okay.

Specific examples of the monomer represented by general formula (XI) and its salts include compounds having the following structures and salts thereof.

（反応式中Ｒ^１８は水素原子またはメチル基を、Ｒ^１９はアミノ酸残基、ポリアミン残基又はアミノアルコール残基を表す。Ｑは酸素原子又はＮＨで表される基を表す。） The monomer represented by general formula (XI) can be synthesized, for example, by an esterification reaction or an amidation reaction using (meth)acrylic acid or (meth)acrylic acid chloride as shown below.

(In the reaction formula, R ¹⁸ represents a hydrogen atom or a methyl group, R ¹⁹ represents an amino acid residue, a polyamine residue, or an amino alcohol residue. Q represents an oxygen atom or a group represented by NH.)

As mentioned above, the fine particle-forming polyvinyl polymer preferably has a hydrophilic side chain, but more preferably does not have an ionizable group.
By not having an ionizable group, an emulsified composition that is less sticky can be obtained.

In general, highly hydrophobic surfactants are suitable for forming water-in-oil emulsion compositions, and conversely, highly hydrophilic surfactants are suitable for forming oil-in-water emulsion compositions. Similarly, the fine particle-forming polyvinyl polymer in the present invention is suitable for forming a water-in-oil emulsion composition when the proportion of hydrophobic constitutional units (constituent units having a hydrophobic side chain) is high. Furthermore, when the proportion of hydrophilic structural units (constituent units having hydrophilic side chains) is high, it is suitable for forming an oil-in-water emulsion composition.
In this way, the emulsified form of the emulsified composition to be formed can be adjusted by appropriately adjusting the proportions and ratios occupied by the hydrophobic structural units and the hydrophilic structural units.

In the present invention, the proportion of hydrophobic constitutional units to the total constitutional units in the fine particle-forming polyvinyl polymer is preferably 1 to 50% by mass, more preferably 20 to 50% by mass, and 30 to 40% by mass.
By setting the proportion of the hydrophobic structural unit in the fine particle-forming polyvinyl polymer within the above range, it is possible to provide an oil-in-water emulsion composition with further reduced stickiness.

In the present invention, the proportion of hydrophilic structural units in the total structural units in the fine particle-forming polyvinyl polymer is preferably 50 to 99% by mass, more preferably 50 to 80% by mass, and 60 to 70% by mass. .
By setting the proportion of the hydrophilic structural unit in the fine particle-forming polyvinyl polymer within the above range, it is possible to provide an oil-in-water type emulsion composition with further reduced stickiness.

In the present invention, the mass ratio of hydrophobic structural units and hydrophilic structural units constituting the fine particle-forming polyvinyl polymer is preferably 10:90 to 50:50, more preferably 20:80 to 50:50, More preferably, the ratio is 30:70 to 40:60.

Further, the molar ratio of hydrophobic structural units to hydrophilic structural units constituting the fine particle-forming polyvinyl polymer is preferably 15:85 to 62:38, more preferably 29:71 to 62:38, and still more preferably 41:59 to 52:48, more preferably 27:73 to 38:62, even more preferably 44:56 to 49:51.
By setting the mass ratio and molar ratio of the hydrophobic constitutional unit and the hydrophilic constitutional unit in the fine particle-forming polyvinyl polymer to the above range, a polyvinyl polymer with excellent emulsifying power suitable for forming an oil-in-water type emulsified composition can be obtained. It can be a fine particle-forming polyvinyl polymer.

In the present invention, the average molecular weight of the fine particle-forming polyvinyl polymer is preferably 2,000 to 11,000, more preferably 20,000 to 80,000, more preferably 30,000 to 80,000, more preferably 40,000 to 70,000, even more preferably 50,000 to 70,000, More preferably, it is 57,000 to 66,000.
Note that the average molecular weight herein refers to the weight average molecular weight in terms of polystyrene measured by GPC.

The contents of the aqueous phase and oil phase in the emulsified composition of the present invention can be adjusted as appropriate by changing the ratio of hydrophobic constitutional units and hydrophilic constitutional units in the fine particle-forming polyvinyl polymer.

The content of the fine particle-forming polyvinyl polymer in the entire emulsified composition is preferably 0.1 to 50% by mass, more preferably 0.5 to 30% by mass.
By setting the content of the fine particle-forming polyvinyl polymer within the above range, the emulsion stability of the emulsion composition can be further improved.

The emulsified composition of the present invention preferably does not substantially contain any emulsifier other than the fine particle-forming polyvinyl polymer.
Here, "substantially no emulsifier other than the fine particle-forming polyvinyl polymer" means that the content of the emulsifier other than the fine particle-forming polyvinyl polymer is 0.3% or less, preferably 0.1% or less. , more preferably 0.1% or less, further preferably 0.01% or less, still more preferably 0.001% or less. Further, it is particularly preferable that no emulsifier other than the fine particle-forming polyvinyl polymer is contained.

Below, the contents of the oil phase and water phase when using a microparticle-forming polyvinyl polymer containing hydrophobic structural units and hydrophilic structural units in a ratio suitable for forming the above-mentioned oil-in-water emulsion composition are shown below. etc. will be explained.
In addition, in this specification, explanation will be made on the assumption that the fine particle-forming polyvinyl polymer in the present invention is not included in the oil phase and oil phase components, and the aqueous phase and aqueous phase components.

The content of the oil phase component in the emulsified composition of the present invention is preferably 0.01 to 80% by mass, more preferably 0.1 to 70% by mass.
By setting the content of the oil phase component within the above range, the emulsion stability of the emulsion composition can be improved.
Note that the oil phase component refers to an oil agent and a lipophilic component, and refers to a component contained in the oil phase in an emulsified composition.

In the emulsion composition of the present invention, the mass ratio of the above-mentioned fine particle-forming polyvinyl polymer to the oil phase component is preferably 1:100 to 1:0.2, more preferably 1:70 to 1:0.3. be.
By setting the mass ratio of the fine particle-forming polyvinyl polymer to the oil phase component within the above range, the emulsion stability of the emulsion composition can be improved.

In the emulsified composition of the present invention, the mass ratio of the oil phase to the aqueous phase is preferably 0.1:99.9 to 70:30, more preferably 1:99 to 65 to 35.
By setting the mass ratio of the oil phase to the aqueous phase within the above range, a stable oil-in-water emulsion composition can be formed.

The components contained in the oil phase and the aqueous phase are not particularly limited.
Examples of the oil agent constituting the oil phase include liquid oil, solid oil, wax, hydrocarbon oil, higher fatty acid, higher alcohol, synthetic ester oil, silicone oil, and the like.

Examples of liquid oils include avocado oil, camellia oil, turtle oil, macadamia nut oil, corn oil, mink oil, olive oil, rapeseed oil, egg yolk oil, sesame oil, persic oil, wheat germ oil, sasanqua oil, castor oil, and linseed oil. , safflower oil, cottonseed oil, eno oil, meadowfoam oil, soybean oil, peanut oil, tea seed oil, kaya oil, rice bran oil, chinensis oil, Japanese tung oil, jojoba oil, germ oil, triglycerin, glycerin trioctanoate, Examples include glycerin triisopalmitate.

Solid fats and oils include cacao butter, coconut oil, horse tallow, hydrogenated coconut oil, palm oil, beef tallow, mutton tallow, hydrogenated beef tallow, palm kernel oil, pork fat, beef bone fat, Japanese oak kernel oil, hydrogenated oil, and beef leg tallow. , Japanese oak oil, hydrogenated castor oil, etc.

Waxes include beeswax, candelilla wax, cotton wax, carnauba wax, bayberry wax, privet wax, spermaceti wax, montan wax, nut wax, lanolin, kapok wax, acetic acid lanolin, liquid lanolin, sugar cane wax, lanolin fatty acid isopropyl, hexyl laurate, reduced lanolin, Jojo Barrow, hard lanolin, shellac wax, POE lanolin alcohol ether, POE lanolin alcohol acetate, POE cholesterol ether, lanolin fatty acid polyethylene glycol, POE hydrogenated lanolin alcohol ether, and the like.

Examples of the hydrocarbon oil include liquid paraffin, ozokerite, pristane, paraffin, ceresin, squalene, petrolatum, microcrystalline wax, and the like.

Examples of higher fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, 12-hydroxystearic acid, undecylenic acid, and tolic acid.

Examples of higher alcohols include cetyl alcohol, stearyl alcohol, behenyl alcohol, batyl alcohol, myristyl alcohol, and cetostearyl alcohol.

Synthetic ester oils include isopropyl myristate, cetyl octoate, octyldodecyl myristate, isopropyl palmitate, butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, hexyldecyl dimethyloctanoate, cetyl lactate, myristyl lactate. , lanolin acetate, isocetyl stearate, isocetyl isostearate, sucrose stearate, sucrose oleate, cholesteryl 12-hydroxystearate, ethylene glycol di-2-ethylhexylate, dipentaerythritol fatty acid ester, N-alkyl glycol monoisostearate, Neopentyl glycol dicaprate, diisostearyl malate, glycerin di-2-heptylundecanoate, trimethylolpropane tri-2-ethylhexylate, trimethylolpropane triisostearate, pentaneerythritol tetra-2-ethylhexylate, tri-2 - Glycerin ethylhexylate, trimethylolpropane triisostearate, cetyl 2-ethylhexanoate, 2-ethylhexyl palmitate, glycerin trimyristate, glycerin tri-2-heptylundecanoate, castor oil fatty acid methyl ester, oleic acid oil, Cetostearyl alcohol, acetoglyceride, 2-heptylundecyl palmitate, cetyl palmitate, diisobutyl adipate, N-lauroyl-L-glutamic acid-2-octyldodecyl ester, di-2-heptylundecyl adipate, ethyl laurate , di-2-ethylhexyl sebatate, 2-hexyldecyl myristate, 2-hexyldecyl palmitate, 2-hexyldecyl adipate, diisopropyl sebatate, 2-ethylhexyl succinate, ethyl acetate, butyl acetate, amyl acetate, citric acid. Examples include triethyl acid.

Examples of silicone oils include linear polysiloxanes such as dimethylpolysiloxane, methylphenylpolysiloxane, and methylhydrogenpolysiloxane, and cyclic polysiloxanes such as decamethylpolysiloxane, dodecamethylpolysiloxane, and tetramethyltetrahydrogenpolysiloxane. can be mentioned.

One type or two or more types of oil agents can be used.

The emulsified composition of the present invention may contain optional additives that are usually added to cosmetics within a range that does not impair the effects of the present invention. Such additive ingredients include, for example, humectants such as polyethylene glycol, glycerin, 1,3-butylene glycol, erythritol, sorbitol, xylitol, and maltitol; lower alcohols such as ethanol; butylated hydroxytoluene, tocopherol, phytin, etc. Antioxidants; Antibacterial agents such as benzoic acid, salicylic acid, sorbic acid, paraoxybenzoic acid alkyl ester, hexachlorophene; para-aminobenzoic acid (hereinafter abbreviated as "PABA"), PABA monoglycerin ester, N,N-dipropoxy PABA ethyl ester , N,N-diethoxy PABA ethyl ester, N,N-dimethyl PABA methyl ester, N,N-dimethyl PABA ethyl ester, N,N-dimethyl PABA butyl ester, N,N-dimethyl PABA 2-ethylhexyl ester, and other benzoic acids. UV absorbers: anthranilic acid UV absorbers such as homomenthyl-N-acetylanthranilate; salicylic acid-based UV absorbers such as amyl salicylate, menthyl salicylate, homomenthyl salicylate, octyl salicylate, phenyl salicylate, benzyl salicylate, p-isopropanol phenyl salicylate Ultraviolet absorber; octyl cinnamate, ethyl-4-isopropyl cinnamate, methyl-2,5-diisopropyl cinnamate, ethyl-2,4-diisopropyl cinnamate, methyl-2,4-diisopropyl cinnamate, propyl-p- Methoxycinnamate, isopropyl-p-methoxycinnamate, isoamyl-p-methoxycinnamate, octyl-p-methoxycinnamate (2-ethylhexyl-p-methoxycinnamate), 2-ethoxyethyl-p-methoxycinnamate, Cyclohexyl-p-methoxycinnamate, ethyl-α-cyano-β-phenylcinnamate, 2-ethylhexyl-α-cyano-β-phenylcinnamate, glyceryl mono-2-ethylhexanoyl-diparamethoxycinnamate, etc. Cinnamic acid UV absorber; [3-bis(trimethylsiloxy)methylsilyl-1-methylpropyl]-3,4,5-trimethoxycinnamate, [3-bis(trimethylsiloxy)methylsilyl-3-methylpropyl] -3,4,5-trimethoxycinnamate, [3-bis(trimethylsiloxy)methylsilylpropyl]-3,4,5-trimethoxycinnamate, [3-bis(trimethylsiloxy)methylsilylbutyl]-3 , 4,5-trimethoxycinnamate, [3-tris(trimethylsiloxy)silylbutyl]-3,4,5-trimethoxycinnamate, [3-tris(trimethylsiloxy)silylbutyl]-3,4,5-tri Silicone cinnamic acid UV absorbers such as methoxycinnamate, [3-tris(trimethylsiloxy)silyl-1-methylpropyl]-3,4-dimethoxycinnamate; 2,4-dihydroxybenzophenone, 2,2'- Dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2'4,4'-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4- Methoxy-4'-methylbenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonate, 4-phenylbenzophenone, 2-ethylhexyl-4'-phenyl-benzophenone-2-carboxylate, 2-hydroxy-4- Benzophenone UV absorbers such as n-octoxybenzophenone and 4-hydroxy-3-carboxybenzophenone; 3-(4'-methylbenzylidene)-d,l-camphor, 3-benzylidene-d,l-camphor, urocanic acid Ethyl ester, 2-phenyl-5-methylbenzoxazole, 2,2'-hydroxy-5-methylphenylbenzotriazole, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, 2-( 2'-Hydroxy-5'-methylphenyl)benzotriazole, dibenzalazine, dianisoylmethane, 4-methoxy-4'-t-butyldibenzoylmethane, 5-(3,3'dimethyl-2-norbornylidene)-3- UV absorbers such as pentan-2-one; organic acids such as acyl sarcosinate (e.g. sodium lauroyl sarcosinate), glutathione, citric acid, malic acid, tartaric acid, lactic acid; vitamin A and its derivatives, vitamin B6 hydrochloride, vitamin B6 Vitamin B such as tripalmitate, vitamin B6 dioctanoate, vitamin B2 and its derivatives, vitamin B12, vitamin B15 and its derivatives, vitamin E such as α-tocopherol, β-tocopherol, γ-tocopherol, vitamin E acetate, vitamin Vitamins such as D, vitamin H, pantothenic acid, pantethine, nicotinamide, and benzyl nicotinate; γ-oryzanol, allantoin, glycyrrhizic acid (salt), glycyrrhetinic acid and its derivatives, tranexamic acid and its derivatives [tranexamic acid derivatives] Examples include dimers of tranexamic acid (for example, trans-4-(trans-aminomethylcyclohexanecarbonyl) hydrochloride aminomethylcyclohexanecarboxylic acid, etc.), esters of tranexamic acid and hydroquinone (for example, trans-4-aminomethyl cyclohexanecarboxylic acid 4'-hydroxyphenyl ester, etc.), esters of tranexamic acid and gentisic acid (for example, 2-(trans-4-aminomethylcyclohexylcarbonyloxy)-5-hydroxybenzoic acid and its salts, etc.), Amides of tranexamic acid (e.g., trans-4-aminomethylcyclohexanecarboxylic acid methylamide and its salts, trans-4-(P-methoxybinzoyl)aminomethylcyclohexanecarboxylic acid and its salts, trans-4-guanidinomethylcyclohexane) carboxylic acids and their salts, etc.)], saponins such as hinokitiol, bisabolol, eucalyptone, thymol, inositol, saikosaponin, carrot saponin, loofah saponin, muclodisaponin, pantothenylethyl ether, ethinylestradiol, tranexamic acid, arbutin , cephalanthine, placenta extract and other various drugs; sage, clara, kouhone, orange, sage, yarrow, mallow, japonica, thyme, horsetail, spruce, birch, horsetail, loofah, horse chestnut, saxifrage, arnica, lily, mugwort, peony, Extracts of plants such as aloe, gardenia, and Japanese mackerel; Pigments; Porous and/or water-absorbing powders (e.g., starches obtained from corn, potatoes, etc., silicic anhydride, talc, kaolin, magnesium aluminum silicate, alginic acid) Powders such as calcium); neutralizing agents; preservatives; fragrances; pigments, etc.

The emulsified composition of the present invention is non-irritating and has little stickiness, so it can be used as cosmetics such as emulsions, creams, serums, sunscreens, and liquid foundations, external skin preparations, quasi-drugs, and pharmaceuticals. is preferred.

<Manufacturing method>
The emulsified composition of the present invention is preferably manufactured by a manufacturing method comprising an aqueous phase preparation step and an emulsification step shown below.

In the aqueous phase preparation step, the fine particle-forming polyvinyl polymer is dispersed in the aqueous phase to form polyvinyl polymer fine particles. At this time, if the emulsified composition contains an electrolyte and/or a polymer that does not satisfy the conditions (A) and (B) above (hereinafter referred to as a specific optional component), water is added in the absence of the specific optional component. It is preferable to disperse the fine particle-forming polyvinyl polymer in the phase to form fine polyvinyl polymer particles, and then add the specific optional component to the aqueous phase.

The method of adding the specific arbitrary component to the aqueous phase is not limited, and for example, a solid or powdered specific arbitrary component may be added to the aqueous phase, or an aqueous solution of the specific arbitrary component may be added to the aqueous phase. good.

Among the specific optional components, examples of the electrolyte include organic acids, inorganic acids, organic bases, inorganic bases, and salts thereof.
Examples of organic acids include citric acid, succinic acid, tartaric acid, acetic acid, malic acid, oxalic acid, lactic acid, boric acid, and adipic acid.
Examples of inorganic acids include hydrochloric acid, phosphoric acid, sulfuric acid, sulfurous acid, and nitric acid.
Examples of the salts of these acids include alkali metal salts such as sodium and potassium; alkanolamine salts such as monoethanolamine and triethanolamine; and aminomethylpropanol salts. More specifically, citric acid, sodium citrate, phosphoric acid, sodium dihydrogen phosphate, sodium monohydrogen phosphate, succinic acid, sodium succinate, tartaric acid, sodium tartrate, acetic acid, sodium acetate, boric acid, lactic acid, Examples include sodium lactate, malic acid, oxalic acid, and adipic acid.

Examples of organic bases include monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, N-dimethylaminoethanolamine, 2-amino-2-methyl-1-propanol, triisopropanolamine, 2-amino- Examples include 2-methyl-1,3-propanediol, 3-amino-1,2-propanediol, 3-dimethylamino-1,2-propanediol, and tris(hydroxymethylamino)methane.
Examples of the inorganic base include sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, sodium bicarbonate, potassium bicarbonate, sodium metasilicate, and potassium metasilicate.
Salts of these bases include salts of organic acids such as citrate, lactate, glycolate, gluconate, acetate, propionate, fumarate, oxalate and tartrate; hydrochloride; Examples include salts of inorganic acids such as carbonates, hydrogen carbonates, sulfates, hydrogen phosphates, and phosphates.

Among the specific optional components, examples of polymers that do not satisfy the above conditions include polyvinyl polymers such as polyolefin polymers, polyacrylic polymers, polyacrylamide polymers, and polystyrene polymers.

The emulsion composition containing the specific optional component produced by the production method of the preferred embodiment described above is particularly excellent in emulsion stability and usability.

In the emulsification step, an oil phase component is added to the aqueous phase containing the polyvinyl polymer fine particles prepared in this manner, and the mixture is stirred and mixed to emulsify the aqueous phase and the oil phase. The method of stirring and mixing is not particularly limited, and a conventional method can be used.

In a preferred embodiment of the present invention, the oil phase is preferably added after all of the fine particle-forming polyvinyl polymer dispersed in the water phase in the water phase preparation step has become polyvinyl polymer fine particles.

The above-described production method is also useful for producing emulsion compositions other than polyvinyl polymers that satisfy conditions (A) and (B).
For example, it can be applied to the production of an emulsion composition in which fine particles made of a polyvinyl polymer satisfying the conditions (A) and (C) described above are adsorbed on the emulsion interface.
That is, an emulsion composition containing a polyvinyl polymer that satisfies the conditions (A) and (C) above, and also contains an electrolyte and/or a polymer that does not satisfy the conditions (A) and (C) above. Can be applied to manufacturing.
In this case, the fine particle-forming polyvinyl polymer is dispersed in the aqueous phase in the absence of the electrolyte and/or the polyvinyl polymer that does not satisfy the above conditions, and the polyvinyl polymer fine particles are formed, and then the fine particles are dispersed in the aqueous phase. An emulsion composition is produced by adding the electrolyte and/or a polyvinyl polymer that does not satisfy the above conditions.
The emulsion composition produced by this production method has excellent emulsion stability and usability.

<Method for evaluating the feeling of use of emulsified composition>
The present invention also relates to a method for evaluating an emulsion composition in which a polymer is adsorbed at an emulsion interface.
In the present invention, any emulsion composition in which a polymer is adsorbed to the emulsion interface can be evaluated without any particular limitation. In other words, the type of polymer adsorbed on the emulsion interface is not limited.

The evaluation method of the present invention is characterized in that the morphology of the dry coating film of the emulsified composition is used as an evaluation index. That is, when 90% or more, more preferably 95% or more, still more preferably 99% or more of the surface layer of the dry coating film of the emulsified composition is occupied by the oil phase, the oil agent contained in the oil phase of the emulsified composition It is judged that the feel is similar to that of

The method for preparing the dry coating film is not particularly limited, but the emulsion composition is applied onto a substrate such as a glass slide or a resin plate, and dried for 30 minutes to 5 hours in an environment of 25°C to 50°C, more preferably at 30°C. A preferred example is a method of drying in an environment of ~40°C for 1 to 3 hours.
The coating method is not particularly limited either, and it is preferable to coat the substrate using an applicator such as a doctor blade, for example.

Although the method for observing the dried coating film is not particularly limited, it is preferable to use a microscope, particularly a confocal laser scanning microscope. Note that when observing with a confocal laser scanning microscope, it is preferable to use a transparent substrate such as a slide glass as the substrate.

When using a confocal laser scanning microscope, fluorescent molecules that serve as markers for the aqueous and oil phases are used in the emulsion composition to be evaluated in order to observe the aspects of the aqueous and oil phases in the dried coating film. Add to.
In other words, an emulsified composition having the same composition as the emulsified composition to be evaluated except for containing the fluorescent molecule is prepared and observed.

As the fluorescent molecule serving as a marker for the aqueous phase, any fluorescent molecule that is localized in the aqueous phase of the emulsified composition can be used without any particular restriction, and for example, Calcein can be mentioned.

As the fluorescent molecule that serves as a marker for the oil phase, any fluorescent molecule localized in the oil phase of the emulsified composition can be used without particular limitation, and for example, NileRed can be mentioned.

A dried coating film containing such fluorescent molecules is observed using a confocal laser scanning microscope to generate a Z-stack image, thereby obtaining a cross-sectional image of the dried coating film. In the cross-sectional image of the dried coating film obtained in this way, the surface layer of the cross-section of the coating film is occupied by a phase that emits fluorescence derived from NileRed, that is, an oil phase that accounts for 90% or more, more preferably 95% or more, and even more preferably 99% or more. If so, it can be judged that the emulsified composition has a feel closer to that of an oil agent.

In other words, if it is observed that the NileRed-derived fluorescent phase is in contact with 90% or more, more preferably 95% or more, still more preferably 99% or more of the upper base in the cross section of the coating film, then the emulsion composition It can be judged that the feel is closer to that of an oil agent.

Furthermore, in a preferred embodiment of the present invention, the aspect of the aqueous phase in the dried coating film is also used as a criterion. That is, when the aqueous phase is in contact with the coating surface in the dry coating film, it can be determined that the emulsified composition has a feel more similar to that of an oil agent.

It is also preferable to observe the aspect of this aqueous phase using a confocal laser scanning microscope. In this case, in the cross-sectional image of the dry coating film, when the fluorescent phase derived from Calcein is in contact with a transparent substrate such as a slide glass, the emulsion composition is judged to have a feel more similar to that of an oil agent. be able to.

Furthermore, if the dried coating film shows a form in which the aqueous phase has parallel striated structures extending upward from the coating surface, it can be determined that the emulsified composition to be evaluated has a feel more similar to that of an oil agent. can.

It is also preferable to observe the morphology of this aqueous phase using a confocal laser scanning microscope. In this case, if the cross-sectional image of the dried coating film shows a form in which the aqueous phase has parallel striated structures extending upward from a transparent substrate such as a slide glass, the emulsion composition to be evaluated is more oily. It can be judged that the feeling is close to that of

In other words, if the fluorescent phase derived from Calcein forms a plurality of convex patterns extending upward from the bottom in the cross section of the coating film, the emulsion composition to be evaluated is It can be judged that the feel is closer to that of an oil agent.

At this time, preferably 90% or more, more preferably 95% or more, still more preferably 99% or more, and even more preferably 100% of all the striated structures appearing in the cross-sectional image are on the transparent substrate, that is, the coating film. It is preferable that it be in contact with the bottom of the cross section.

Furthermore, when fine particles made of a polymer are adsorbed on the emulsion interface of an emulsion composition, it can be evaluated that the emulsion stability and stickiness are excellent.
Whether fine particles are adsorbed to the emulsion interface can be observed using a scanning electron microscope.

<Method for designing emulsion composition>
The method for designing an emulsion composition of the present invention includes a first selection step and a second selection step.
The first selection step is a step of selecting a polymer that has an emulsifying effect. In the first selection step, a polymer known to have an emulsifying effect may be selected, or a polymer having an emulsifying effect may be selected by actually conducting an emulsifying test.
In the method for designing an emulsified composition of the present invention, the type of polymer that is a candidate for the polymer emulsifier is not particularly limited.

The second selection step is characterized in that the morphology of the dry coating film of the emulsified composition emulsified with the polymer selected in the first selection step is used as a judgment index. That is, when 90% or more, more preferably 95% or more, still more preferably 99% or more of the surface layer of the dry coating film of the emulsified composition is occupied by the oil phase, the used polymer can be used as a polymer emulsifier. select.

Regarding the embodiment of the method of observing the dried coating film of the emulsified composition, the above description regarding the method for evaluating the feeling of use of the emulsified composition can be applied.

In a preferred embodiment of the present invention, it is preferable to further include a third selection step.
That is, in a preferred embodiment of the present invention, an emulsion composition is prepared using a selected polymer, and when it is confirmed that fine particles made of the polymer are adsorbed on the emulsion interface, the polymer is A third selection step is performed in which the polymer emulsifier is selected as a more preferable polymer emulsifier.
By including the third selection step, it is possible to design an emulsified composition that has a feel closer to that of an oil agent.

<Polymer emulsifier>
The present invention also relates to a polymer emulsifier made of a polyvinyl polymer that satisfies the conditions (A) and (B) described above. Regarding the embodiments of the polymer emulsifier of the present invention, the description regarding the emulsified composition of the present invention can be applied.

(1) Synthesis of Polyvinyl Polymer 1 Polyvinyl Polymer 1 was synthesized by copolymerizing a hydrophilic monomer having the following structure and a hydrophobic monomer at a mass ratio of 7:3.

hydrophilic monomer

hydrophobic monomer

(2) Evaluation of physical properties of polyvinyl polymer 1 (2-1) Average molecular weight of polyvinyl polymer 1 When the weight average molecular weight in terms of polystyrene was measured by GPC, the average molecular weight of polyvinyl polymer 1 was 61,000. .

(2-2) Viscosity of aqueous solution of polyvinyl polymer 1 Aqueous solutions containing polyvinyl polymer 1 at 0.1% by mass, 0.5% by mass, and 1.0% by mass were prepared, respectively. The viscosity of this aqueous solution was measured with a B-type viscometer (No. 3 rotor, 6 rpm, 1 mm, 20° C., 1 atm) and found to be less than 2000 mPa·S. Further, no concentration-dependent thickening effect of polyvinyl polymer 1 was observed.

(3) Preparation of emulsified composition Polyvinyl polymer 1 was dispersed in water (polyvinyl polymer 1:water = 1:89). When this aqueous solution was measured by dynamic light scattering measurement based on the laser Doppler method (Zetasizer Nano-Z ZEN3600, Malvern), it was confirmed that fine particles with an average particle diameter of 20 nm were formed.

After confirming the formation of fine particles, by adding squalane, caprylic/capric acid glyceryl triglyceride, cetyl 2-ethylhexanoate, and dimethicone (10 cP) to the aqueous solution, stirring and mixing. Four types of oil-in-water type emulsified compositions (polyvinyl polymer 1:oil agent:water=1:10:89) were prepared. For comparison, four comparative oil-in-water emulsion compositions were also prepared in which the ratio of oil agent to water was 10:89.

The oil-water interfacial tension of a total of eight emulsion compositions prepared above was measured by the pendant drop method. The results are shown in Table 1 below.

As shown in Table 1, a decrease in the oil-water interfacial tension was observed with the addition of Polyvinyl Polymer 1, regardless of the emulsion composition prepared with any oil agent.
Considering this result together with the results of dynamic light scattering measurements when polyvinyl polymer 1 was dispersed in water, it was found that polyvinyl polymer 1 is in the form of fine particles and adsorbs to the oil-water interface due to van der Waals forces. It was suggested that

(4) Evaluation of emulsified composition 1
(4-1) Observation with an electron microscope Among the emulsified compositions prepared above, the emulsified compositions of Examples containing squalane as an oil agent were observed with a scanning electron microscope. An electron microscope image is shown in Figure 1.

As shown in FIG. 1, irregularities were observed on the surface of the oil droplets dispersed in the emulsified composition of the example. From this, it was confirmed that the polyvinyl polymer 1 in the form of fine particles was adsorbed to the emulsion interface of the oil droplets dispersed in the emulsion composition of the example and covered the entire surface thereof.

(4-2) Emulsion stability evaluation test (1)
The emulsified composition of the example containing squalane as an oil agent was allowed to stand at room temperature for 2 months. As a result, coalescence of oil droplets, which is an indicator of emulsion instability, was not observed. This result shows that the emulsion composition of the example has excellent emulsion stability.

(4-3) Evaluation of emulsion stability (2)
When 2% NaCl was added to the emulsified composition of the example containing squalane as an oil agent and the emulsified state was observed, a stable emulsified state was maintained without becoming unstable. This result shows that the emulsified composition of the example was able to achieve the emulsification as shown in (4-2) above due to steric repulsion rather than electrostatic repulsion of the fine particles made of polyvinyl polymer 1 adsorbed on the emulsion interface. This shows that it exhibits stability.

(5) Evaluation test 2 of emulsified composition
(5-1) Preparation of emulsified composition The emulsified composition of Example 1 having the composition shown in Table 2 was prepared by the following method. First, polyvinyl polymer 1 was dispersed in a portion of pure water to form fine particles made of polyvinyl polymer 1. This dispersion of fine particles of polyvinyl polymer 1 and the remaining water phase components were mixed to prepare an aqueous phase. This aqueous phase was mixed and stirred with oil phase components to prepare an oil-in-water type emulsified composition of Example 1.

An oil-in-water emulsion composition of a comparative example having the composition shown in Table 3 was prepared.

(5-2) Observation of cross section of emulsified composition The emulsified compositions of Example 1 and Comparative Example were applied to a slide glass using a doctor blade (0.01 inch). This was left in a 35°C environment for 2 hours to dry the coating film.
The dried coating film thus obtained was observed using a confocal laser scanning microscope (manufactured by Carl Zeiss), and Z-stack images were obtained to obtain cross-sectional images of the dried coating film (FIGS. 2 to 5).

Note that the observation conditions using a confocal laser scanning microscope are as follows.
Calcein: Excitation wavelength 488nm, observation wavelength 505-550nm
NileRed: Excitation wavelength 561 nm, observation wavelength 575 nm ~

As shown in FIG. 2, the surface layer of the dry coating film of the emulsified composition of Example 1 is entirely occupied by a phase that emits fluorescence derived from NileRed. That is, in the dried coating film of the emulsified composition of Example 1, a large amount of the oil phase was exposed on the surface.

Moreover, as shown in FIG. 2, in the dry coating film of the emulsified composition of Example 1, the phase that emits fluorescence derived from Calcein is in contact with the slide glass. More specifically, the phase that emits fluorescence derived from Calcein exhibits a form in which vertically extending striated structures are arranged in parallel, and all of the striated structures are in contact with the slide glass.
That is, in the dry coating film of the emulsified composition of Example 1, the aqueous phase containing the polyvinyl polymer 1 was adsorbed on the coating surface.

On the other hand, as shown in FIG. 3, in the dry coating film of Comparative Example 1, a phase that emits fluorescence derived from NileRed and a phase that emits fluorescence derived from Calcein are mixed with each other. There is a very small portion of the surface layer in which the phase that emits fluorescence derived from NileRed constitutes the surface layer, and the phase that emits fluorescence derived from Calcein constitutes the surface layer.
That is, in the dry coating film of the emulsified composition of Comparative Example 2, the aqueous phase and oil phase are mixed in the thickness direction, and the oil phase is only partially exposed on the surface.

In addition, as shown in FIG. 4, in the dry coating film of the emulsified composition of Comparative Example 2, the NileRed-derived fluorescent phase was in contact with the slide glass over the entire area and did not constitute the surface layer. There are only a few parts.
That is, in the dry coating film of the emulsified composition of Comparative Example 2, the oil phase was adsorbed on the coating surface and was only partially exposed on the surface of the coating film.

As shown in FIG. 5, in the dry coating film of the emulsified composition of Comparative Example 3, the NileRed-derived fluorescent phase was almost uniformly separated on the slide glass side, and the Calcein-derived fluorescent phase was almost uniformly separated on the surface layer side. There is.
In other words, in the dry coating film of the emulsified composition of Comparative Example 3, the oil phase was adsorbed on the coating surface and was not substantially exposed on the surface.

(5-3) Evaluation of feel of emulsified composition 1
The feel of the coating films of the emulsified compositions of Examples and Comparative Examples was evaluated by the following method. First, the emulsion compositions of Example 1 and Comparative Example were applied onto artificial leather using a doctor blade (0.01 inch). This was left in a 35°C environment for 2 hours to dry the coating film.

The feel of this dry coating film was quantitatively evaluated using MIU (average coefficient of friction) and MMU (uniformity of average coefficient of friction). MIU and MMU were measured using a tribometer (manufactured by Kato Tech, KES-SE method) under the following measurement conditions.
(Measurement conditions) Sensitivity: High, static load: 50g, probe movement speed: 10mm/sec

At this time, as a comparison target, a coating film formed by applying two types of oils, glyceryl tri(2-ethylhexanoate) and diisostearyl malate, onto artificial leather using a doctor blade (0.01 inch); The same measurements were also performed on coffee filters, copy paper, and silk fabrics.

FIG. 6 shows a diagram in which MMU is plotted on the vertical axis and MIU is plotted on the horizontal axis. As shown in FIG. 6, it was found that the coating film of glyceryl tri(2-ethylhexanoate), which is an oil agent, had a feel that was relatively similar to that of silk fabric.
On the other hand, the dried coating films of the emulsified compositions of Comparative Examples 1 to 3 had a feel different from that of silk fabric, even though the oil phase contained the same oil agent (FIG. 6).
However, as shown in FIG. 6, the dry coating film of the emulsified composition of Example 1, which also contains glyceryl tri(2-ethylhexanoate), exhibits a feel very similar to that of silk fabric.
This result shows that the emulsified composition of Example 1 exhibits the feel inherent to the oil agent contained in the oil phase.

(5-3) Evaluation of feel of emulsified composition 2
Four experienced evaluators applied the emulsified compositions of Example 1 and Comparative Example 3 to their skin, and compared and evaluated the feel.
As a result, all the evaluators evaluated that the emulsified composition of Example 1 felt more fresh. Furthermore, three out of four evaluators evaluated that the emulsified composition of Example 1 was less sticky and felt like silk fabric.

(6) Evaluation of manufacturing method Various emulsified compositions were manufactured which had the same composition as the emulsified composition of Example 1 but were manufactured using different manufacturing methods. That is, in the presence of an electrolyte, a polyvinyl polymer, or both, polyvinyl polymer 1 is dispersed in an aqueous phase to prepare an aqueous phase, and then mixed with an oil phase and stirred to prepare an emulsion composition of a comparative example. did.
As a result, even though they had the same composition, the emulsion composition of Example 1 was superior in emulsion stability and feel of the coating film compared to the emulsion compositions of any of the comparative examples.

(7) Summary The emulsified composition of the example exhibits the original feel of the oil agent contained in the oil phase (see (5-3) above). This can be said to be an effect due to the fact that a large amount of the oil phase is exposed on the surface of the dried coating film of the emulsified composition of the example, as shown in (5-2) above.

By the way, conventional polymer emulsifiers exhibit high viscosity when they are in the form of aqueous solutions. Therefore, emulsified compositions using conventional polymer emulsifiers have a problem in that they become sticky when trying to achieve high stability.

On the other hand, Polyvinyl Polymer 1 has low viscosity as shown in (2-2) above, and the emulsified composition of Example 1 emulsified with it also had low viscosity and was not easily sticky ( (See (4-3) above). Nevertheless, the emulsion composition of Example 1 had high emulsion stability (see (4-2) and (4-3) above).

In addition, as shown in (3) above, polyvinyl polymer 1 is in a particle state when dispersed in water, and it is suggested that it is adsorbed in the form of fine particles to the oil-water interface by van der Waals forces. Ta. As shown in (4-1) above, considering the results that unevenness was observed on the surface of oil droplets dispersed in the emulsified composition, the emulsion interface of the emulsified composition of Example 1 has a polyvinyl-based It can be seen that Coalescence 1 is adsorbed in the form of fine particles.

These results indicate that an emulsion composition in which a polyvinyl polymer that satisfies conditions (A) and (B) explained in this specification is adsorbed at the emulsion interface has high emulsion stability while having low stickiness. This shows that it exhibits the original feel of the oil agent contained in the oil phase.

The present invention can be applied to emulsified cosmetics.

Claims (4)

A method for evaluating an emulsion composition in which a polymer is adsorbed to an emulsion interface, the method comprising:
When 90% or more of the surface layer of the dry coating film of the emulsified composition is occupied by the oil phase,
characterized in that the dry coating film of the emulsified composition is determined to have a feel similar to that of the original dry coating film of the oil agent contained in the oil phase of the emulsified composition,
A method for evaluating the feeling of use of an emulsified composition. When the aqueous phase is in contact with the coating surface in the dry coating film,
The use of the emulsified composition according to claim 1, wherein the dry coating film of the emulsified composition is determined to have a feel similar to that of the original dry coating film of the oil agent contained in the oil phase of the emulsified composition. How to evaluate feelings. The method for evaluating the feel of an emulsified composition according to claim 1 or 2, wherein the feel of the dry coating film is evaluated based on an average coefficient of friction and uniformity of the average coefficient of friction. a first selection step of selecting a polymer with emulsifying action;
Observe the dry coating film of the emulsified composition emulsified with the polymer selected in the first selection step, and if 90% or more of the surface layer is occupied by the oil phase, select the polymer as the polymer emulsifier. A method for designing an emulsion composition, comprising: a second selection step.