JP7777924B2 - O/W type cosmetic containing polymer containing cationic groups - Google Patents

Description

The present invention relates to cosmetics. More specifically, it relates to a cosmetic composition containing a polymer containing cationic groups and α-gel, which is used in skin cosmetics, topical skin preparations, hair cosmetics, etc.

Polymers containing cationic groups are often used in cosmetics. For example, Patent Document 1 describes an oil-in-water emulsion composition containing (A) a solid hydrocarbon oil, (B) waxes, (C) polyoxyethylene cetyl ether (15 to 25 EO), and (D) a cationic polymer. It describes the use of a copolymer of methylvinylimidazolinium, a polymer containing amino groups, and vinylpyrrolidone as the cationic polymer (D), and also describes the use of a carboxyl vinyl polymer as a thickener.
For example, Patent Document 2 describes an oil-in-water emulsion composition emulsified with a polyion complex formed from a polymer containing a cationic group and carboxymethyl cellulose. It describes that O-[2-hydroxy-3-(trimethylammonio)propyl]hydroxyethyl cellulose chloride is used as the polymer containing a cationic group.

JP 2011-102258 A JP 2011-32249 A

As described above, the use of polymers containing cationic groups as cosmetic ingredients has been proposed, and they are commonly used in combination with anionic polymers such as carboxyvinyl polymers and carboxymethyl cellulose to stabilize or thicken oil-in-water cosmetic compositions containing polymers containing cationic groups. However, such cosmetic compositions often exhibit insufficient storage stability, such as the formation of aggregates. Therefore, an object of the present invention is to provide a novel cosmetic composition that contains a polymer containing cationic groups and has good stability over time.

The present inventors have conducted various studies to achieve the above object and have arrived at the present invention.
That is, the present invention comprises: (a) a polymer containing a cationic group;
(b) an α-gel containing a nonionic surfactant.

The cosmetic composition of the present disclosure has excellent storage stability over time. Therefore, it can be preferably used, for example, as a cosmetic ingredient for skin care and hair care.

1 is a chart showing the results of XRD (small angle) measurement of the compositions obtained in Production Example 1, Comparative Production Example 1, Production Example 7, and Comparative Production Example 2. 1 is a chart showing the results of XRD (wide angle) measurement of the compositions obtained in Production Example 1, Comparative Production Example 1, Production Example 7, and Comparative Production Example 2. 1 is a chart showing the results of XRD (small angle) measurement of the compositions obtained in Production Example 8 and Comparative Production Example 3. 1 is a chart showing the results of XRD (wide angle) measurement of the compositions obtained in Production Example 8 and Comparative Production Example 3.

The present disclosure will be described in detail below.
In addition, a combination of two or more of the individual preferred embodiments of the present disclosure described below is also a preferred embodiment of the present disclosure.

<Polymer containing cationic groups>
In the present disclosure, a polymer containing a cationic group refers to a polymer containing a cationic group in its structure. For example, it is a homopolymer polymerized using a monomer containing a cationic group, a copolymer of a monomer having a cationic group and another monomer not containing a cationic group, or a compound obtained by reacting a polymer with a compound containing a cationic group. In the case of a copolymer, the monomer having a cationic group preferably accounts for 30% by mass or more of the entire copolymer, more preferably 40% by mass or more, particularly preferably 50% by mass or more, and most preferably 60% by mass or more. In the case of a compound obtained by reacting a polymer with a compound containing a cationic group, the cationic group-containing portion is preferably 10% by mass or more, more preferably 20% by mass or more, based on the total mass of the compound (100% by mass).
Polymers containing cationic groups may have antibacterial properties. Antibacterial properties refer to the ability to kill microorganisms (kill microorganisms), bacteriostasis (suppress the growth of microorganisms), sterilization, disinfection, bacteriostatic, antibacterial, antifungal, etc. Microorganisms that are the subject of the present disclosure include, but are not limited to, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida, and Aspergillus niger. For example, polymers containing cationic groups exhibit antibacterial properties against the above-mentioned bacteria.
In the present disclosure, the amount of the polymer containing a cationic group is preferably 0.0001 part by mass or more, and more preferably 0.0002 part by mass or more, relative to 100% by mass of the α-gel containing the nonionic surfactant described below.

<Cationic Group>
In the present disclosure, a cationic group refers to a group having a cation or a group that generates a cation, and is not particularly limited, but examples thereof include primary to tertiary amino groups, quaternary ammonium bases, etc. Among primary to tertiary amino groups and quaternary ammonium bases, a tertiary amino group or a quaternary ammonium base is preferred as the cationic group.

<Primary to Tertiary Amino Groups>
The primary to tertiary amino groups include those represented by the following formula (1):

(wherein _R1 and _R2 are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms). The hydrocarbon group is preferably an alkyl group, an alkenyl group, or an aryl group, more preferably an alkyl group or an alkenyl group, and even more preferably an alkyl group. The hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, particularly preferably 1 to 5 carbon atoms, and most preferably 1 to 2 carbon atoms.
At least one of _R1 and _R2 is preferably a hydrocarbon group having 1 to 12 carbon atoms, and more preferably both _R1 and _R2 are hydrocarbon groups having 1 to 12 carbon atoms. Among the primary to tertiary amino groups, a tertiary amino group is preferred. As the tertiary amino group, a dimethylamino group or a diethylamino group is preferred.

<Quaternary ammonium base>
The quaternary ammonium base may be a compound represented by the following formula (2):

(wherein R ₃ to R ₅ are the same or different and represent a hydrocarbon group having 1 to 12 carbon atoms.) The hydrocarbon group is preferably an alkyl group, an alkenyl group, or an aryl group, more preferably an alkyl group or an alkenyl group, and even more preferably an alkyl group. The number of carbon atoms in R ₃ to R ₅ is more preferably 1 to 10, even more preferably 1 to 7, and particularly preferably 1 to 5.
As the hydrocarbon group for R ₃ to R ₅ , a methyl group or an ethyl group is most preferred.

<Method for producing polymer containing cationic groups>
In the present disclosure, the method for producing a polymer containing a cationic group is not particularly limited, but it can typically be produced by polymerizing a monomer containing a cationic group. In the present disclosure, examples of monomers containing a cationic group include those having at least one ethylenically unsaturated group and one cationic group. For example, a polymer can be produced by polymerizing a monomer containing a primary to tertiary amino group or a quaternary ammonium salt group alone, or, if necessary, by polymerizing it with other monomers that do not contain a cationic group. In addition to production methods using other ethylenically unsaturated groups, for example, a cellulose-based polymer containing a cationic group can be produced by reacting the alcohol groups of cellulose with an etherifying agent such as ethylene oxide to form a cellulose ether, which can then be reacted with a glycidyl group having a cationic group. For example, polyaminoalkylbiguanide can be produced by reacting dicyandiamide with an alkyl-containing diamine. Other cationic-containing polymers can be produced by known production methods.

<Monomer containing a cationic group>
In the present disclosure, examples of the monomer containing the cationic group include the monomers containing the above-mentioned primary to tertiary amino groups in the structure and the monomers containing a quaternary ammonium salt group in the structure. Specific examples include N,N-dialkylamino group-containing (meth)acrylates such as N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, and N,N-diethylaminopropyl (meth)acrylate, as well as monomers obtained by adding a quaternizing agent to the above-mentioned monomers, or neutralized products thereof with an acid such as hydrochloric acid or acetic acid; N,N-dimethylaminoethyl (meth)acrylamide, N,N-diethylaminoethyl (meth)acrylamide, N, N,N-dialkylamino group-containing (meth)acrylamides such as N-dimethylaminopropyl(meth)acrylamide and N,N-diethylaminopropyl(meth)acrylamide, and monomers obtained by adding a quaternizing agent to the above monomers, or products thereof neutralized with an acid such as hydrochloric acid; monoalkylamino group-containing (meth)acrylates such as monomethylaminoethyl(meth)acrylate, monoethylaminoethyl(meth)acrylate, monomethylaminopropyl(meth)acrylate, monoethylaminopropyl(meth)acrylate, and 2-(tert-butylamino)ethyl (meth)acrylate, and products thereof neutralized with an acid such as hydrochloric acid; monoalkylamino group-containing (meth)acrylamides such as monomethylaminoethyl(meth)acrylamide, monoethylaminoethyl(meth)acrylamide, monomethylaminopropyl(meth)acrylamide, and monoethylaminopropyl(meth)acrylamide, and products thereof neutralized with an acid such as hydrochloric acid; esters of (meth)acrylic acid and alkanolamines such as 2-aminoethyl (meth)acrylate, and products thereof neutralized with an acid such as hydrochloric acid. or a neutralized product thereof with an acid such as hydrochloric acid; N,N-diallylmethylamine or a monomer obtained by adding a quaternizing agent thereto or a neutralized product thereof with an acid such as hydrochloric acid; allylamine or a neutralized product thereof with an acid such as hydrochloric acid; an addition reaction product of an unsaturated monomer having a cyclic ether-containing group having 2 to 8 carbon atoms, such as 1-allyloxy-3-dibutylamino-2-ol or 1-allyloxy-3-diethanolamino-2-ol, with an amine compound having 1 to 24 carbon atoms, or a monomer obtained by adding a quaternizing agent thereto or a neutralized product thereof with an acid such as hydrochloric acid. Particularly preferred are N,N-dialkylamino group-containing (meth)acrylates such as N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, and N,N-diethylaminopropyl (meth)acrylate, as well as monomers obtained by adding a quaternizing agent to the above monomers or a neutralized product thereof with an acid such as hydrochloric acid or acetic acid.

<Other monomers>
In the present disclosure, the other monomer that can be copolymerized with the above-mentioned monomer containing a cationic group is a monomer that does not contain a cationic group, and is not particularly limited as long as it is a monomer that can be copolymerized with the monomer containing a cationic group. vinyl halides such as vinyl chloride; alkyl vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; addition reaction products of unsaturated monomers having a cyclic ether-containing group having 2 to 8 carbon atoms, such as 1-allyloxy-3-butoxypropan-2-ol, with alcohols having 1 to 20 carbon atoms; alkylene oxide adducts of unsaturated alcohols having 2 to 20 carbon atoms, such as an ethylene oxide adduct of allyl alcohol, an ethylene oxide adduct of methallyl alcohol, and an ethylene oxide adduct of isoprenol, and terminally hydrophobically modified products thereof; and cyclic vinyl monomers such as N-vinylpyrrolidone.

In order to adjust the viscosity, a monomer having two or more ethylenically unsaturated groups may be included. Examples of the monomer having two or more ethylenically unsaturated groups include esters of (meth)acrylic acid with di- or more substituted hydroxyl groups of polyols such as ethylene glycol, propylene glycol, polyoxyethylene glycol, polyoxypropylene glycol, glycerin, polyglycerin, trimethylolpropane, pentaerythritol, sucrose, sorbitol, and 1,4-butanediol; di- or more substituted methacrylic acid esters of the above polyols; ethers of di- or more substituted hydroxyl groups of the above polyols with unsaturated alcohols such as allyl alcohol and vinyl alcohol; diallyl phthalate, triallyl phosphate, allyl methacrylate, tetraallyloxyethane, triallyl cyanurate, divinyl adipate, vinyl crotonate, 1,5-hexadiene, and divinylbenzene. These other monomers may be used alone, or two or more types may be used in combination.
Among these, monomers containing an alkyl group having two or more carbon atoms are preferred because they have the effect of enhancing antibacterial properties, and ethyl (meth)acrylate and butyl (meth)acrylate are particularly preferred.

<α Gel containing nonionic surfactants>

<α Gel>
In the present disclosure, α-gel has a layered structure called a lamellar structure, in which surfactants are packed in a hexagonal crystal structure. It is in a hydrated crystalline state, with a large amount of water held between the layers. Therefore, in X-ray diffraction measurements, peaks indicating a specific period due to the lamellar structure can usually be observed in small-angle X-ray scattering, while sharp peaks due to the crystalline structure can be observed in wide-angle X-ray scattering.
The cosmetic composition of the present disclosure preferably has at least one peak in the diffraction angle (2θ) of around 20° to 24° by X-ray diffraction (wide angle), and more preferably has one peak in the diffraction angle (2θ) of around 21° to 22°. The half-width (deg) of the peak observed in the X-ray diffraction (wide angle) is preferably 0.17 or more and 2.0 or less, more preferably 0.19 or more and 0.8 or less, and particularly preferably 0.20 or more and 0.8 or less. The crystallinity of α-gel is calculated using the following formula from the diffraction intensity of the crystalline portion in the X-ray diffraction around 2θ = 21° to 22° and the diffraction intensity of the amorphous portion in 2θ = 10° to 50°.
Crystallinity (%) = sharp peak area around 21° to 22° ÷ (sharp peak area around 21° to 22° + peak area of amorphous portion between 10° and 50°) × 100. In the present disclosure, the crystallinity is preferably 0.3% or more, and particularly preferably 1.0% or more. Within the above numerical range, the crystallinity of the formed α-gel is high, and the stability of the cosmetic composition tends to be improved. The α-gel of the present disclosure preferably contains a nonionic surfactant and water. The amount of water contained in the α-gel of the present disclosure is preferably 500% by mass or more, more preferably 600% by mass or more, even more preferably 700% by mass or more, and particularly preferably 800% by mass or more, relative to 100% by mass of the nonionic surfactant.

<Nonionic surfactant>
In the present disclosure, a nonionic surfactant is a compound that does not exhibit ionic properties when dissolved in water but has surface-active properties.
For example, the ester type is an ester of a fatty acid and an alcohol, or an ester of a fatty acid and a sugar. Examples include glycerin fatty acid ester, sorbitan fatty acid ester, sucrose fatty acid ester, polyglycerin fatty acid ester, etc. The fatty acid is a carboxylic acid having a hydrocarbon group, and the number of carbon atoms in the hydrocarbon group is preferably 2 to 25, more preferably 8 to 22, and particularly preferably 8 to 18. For example, the ether type includes alkyl polyalkylene glycol, which is a compound in which an alkylene oxide is added to a long-chain alcohol, such as alkyl polyethylene glycol and polyoxyethylene alkyl phenyl ether.

In one preferred embodiment of the nonionic surfactant of the present disclosure, two or more types of nonionic surfactants with different HLB (Hydrophilic-Lipophilic Balance) values can be used. The HLB (Hydrophilic-Lipophilic Balance) value is a value that indicates the degree of affinity of a surfactant for water and oil. For example, if the HLB value is 8 to 16, the surfactant will be stably dispersed in water and can be suitably used as an O/W emulsifier. If the HLB value is 3 to 6, the surfactant will have low solubility in water but can be slightly dispersed and can be suitably used as a W/O emulsifier.
When two or more surfactants with different HLB values are used, at least one selected from nonionic surfactants with an HLB value of 8 to 16 and one or more selected from nonionic surfactants with an HLB value of 3 to 6 are used. By using two nonionic surfactants with different HLB values, the bilayer membrane structure that constitutes α-gel is fixed, forming a strong bilayer membrane, and the strength of the formed oil droplets is increased and stabilized. For example, a nonionic surfactant with an HLB value of 8 to 16 is a polyglycerol fatty acid ester, and polyglyceryl stearate 5 is particularly preferred. For example, a nonionic surfactant with an HLB value of 3 to 6 is a glycerol fatty acid ester, and glyceryl stearate is particularly preferred.
When using one or more nonionic surfactants with an HLB value of 8 to 16 and one or more nonionic surfactants with an HLB value of 3 to 6, the proportion of the one or more nonionic surfactants with an HLB value of 8 to 16 relative to the total mass % of nonionic surfactants is preferably 30% to 90% by mass. This range stabilizes the crystalline structure of α-gel. When mixing two or more surfactants with different HLB values as described above, a higher alcohol may also be used as needed. The higher alcohol is an alcohol having a hydrocarbon group with 8 or more carbon atoms, and the hydrocarbon group may be linear or branched. It is particularly preferable to use a combination of one or more surfactants with 14 to 22 carbon atoms.

In another preferred embodiment of the nonionic surfactant disclosed herein, when a nonionic surfactant with an HLB value of 8 to 16 is used, it is preferable to use a higher alcohol when one or more nonionic surfactants selected from those with an HLB value of 3 to 6 are not used. By using such a nonionic surfactant with a high HLB value and a higher alcohol, the bilayer membrane structure that constitutes α-gel is fixed, forming a strong bilayer membrane, and the strength of the formed oil droplets is increased and stabilized. The higher alcohol is an alcohol having a hydrocarbon group with 8 or more carbon atoms, and the hydrocarbon group may be linear or branched. It is particularly preferable to use a combination of one or more types of surfactants with 14 to 22 carbon atoms.

<Water>
In the present disclosure, examples of water include purified water, distilled water, ion-exchanged water, pure water, soft water, hard water, natural water, deep sea water, alkaline ionized water, and purified water obtained by various other methods.
The cosmetic composition of the present disclosure preferably contains water at 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, based on 100% by mass of the total cosmetic composition. On the other hand, the cosmetic composition of the present disclosure preferably contains water at 99% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less, based on 100% by mass of the total cosmetic composition. Within the above range, the feel during use and storage stability of the cosmetic composition of the present disclosure tend to be further improved.

<Other constituent substances>
The cosmetic composition of the present disclosure may contain substances other than the above-mentioned (a) polymer containing a cationic group and (b) α-gel containing a nonionic surfactant and water. Examples include alcohol, thickener, powder component, pH adjuster, anionic surfactant, cationic surfactant, amphoteric surfactant, oil, moisturizer, water-soluble polymer, antioxidant, UV absorber, chelating agent, preservative, antibacterial agent, colorant, fragrance, etc. Any substance typically incorporated into cosmetics can be appropriately incorporated. The content of the above other components is not particularly limited as long as it does not impair the stability of the cosmetic composition, but it is preferably 0 to 50% by mass relative to 100% by mass of the cosmetic composition.

[Physical properties of the cosmetic composition containing the cationic group-containing polymer of the present disclosure]
A cosmetic composition containing a cationic group-containing polymer of the present disclosure (hereinafter also referred to as the cosmetic composition of the present disclosure) preferably has a viscosity suitable for use in cosmetic applications, preferably 1000 mPa·s or greater. The cosmetic composition of the present disclosure has excellent long-term storage stability under normal storage conditions. The cosmetic composition of the present disclosure preferably has a pH in the range of 2.0 to 8.0. When the cosmetic composition of the present disclosure has a pH in the above range, it can be used appropriately for cosmetic applications. The cosmetic composition of the present disclosure has a usability equivalent to or superior to that of an α-gel containing a nonionic surfactant. When the cationic group-containing polymer has antibacterial properties against various bacteria, the cosmetic composition of the present disclosure can be used as a cosmetic composition while maintaining the antibacterial properties of the cationic group-containing polymer. For these reasons, the cosmetic composition containing a cationic group-containing polymer of the present disclosure can be used appropriately for cosmetic applications.

[Method for producing a cosmetic composition containing a polymer containing a cationic group according to the present disclosure]
The cosmetic composition containing the cationic group-containing polymer of the present disclosure is not particularly limited and can be produced by mixing the cationic group-containing polymer with an α-gel containing a nonionic surfactant. An appropriate solvent can be selected based on the characteristics of the cationic group-containing polymer used. The solvent can be selected from those commonly used in cosmetics, such as water, alcohols, specifically ethanol, polyhydric alcohols, etc., with water being preferred. The device used to mix the cationic polymer and the α-gel containing a nonionic surfactant is not particularly limited, and any commonly used stirring device can be used. Examples include a homomixer, a homodisper, and a three-one motor, with a homomixer being preferred. The temperature conditions during mixing are not particularly limited, but it is preferable to mix the cationic group-containing polymer and the α-gel containing a nonionic surfactant at a temperature that enhances their miscibility, for example, 40°C or higher, preferably 60°C or higher, and preferably 90°C or lower.

[Uses of cosmetic compositions containing the cationic group-containing polymer of the present disclosure]
A cosmetic composition containing a polymer containing a cationic group according to the present disclosure can exhibit high storage stability in cosmetic applications and can be preferably used as a cosmetic composition for use in skin cosmetics, topical skin preparations, hair cosmetics, and the like.
Cosmetics in the present disclosure refer to cosmetics and quasi-drugs that are applied directly to human skin, and specifically include skin cosmetics, topical skin preparations, skin cleansers, hair cosmetics, topical hair preparations, hair cleansers, etc. Cosmetic compositions containing the cationic group-containing polymer of the present disclosure are excellent in feel during use and have high storage stability, and are therefore preferably applicable to skin care cosmetic applications, hair care cosmetic applications, etc.
A cosmetic composition containing the cationic group-containing polymer of the present disclosure can be preferably applied to the various uses described above because the antibacterial properties are maintained when the cationic group-containing polymer has antibacterial properties.

The present invention will be explained in more detail below with reference to the following examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" means "parts by mass" and "%" means "% by mass."

<Weight average molecular weight (Mw) measurement>
Apparatus: Tosoh EcoSEC HLC-8320GPC
Detector: differential refractometer (RI) Detector column: TSKgel α-M, α-2500 manufactured by Tosoh Corporation
Column temperature: 40°C
Flow rate: 0.4mL/min
Injection volume: 20 μL (eluent preparation solution with sample concentration of 0.4 wt %)
Calibration curve: Polyethylene glycol manufactured by GL Sciences Eluent: 0.5 M acetic acid + 0.2 M Na nitrate/acetonitrile = 50/50 (v/v)
<Compatibility>
Those that were able to be mixed uniformly were marked with an ◯, and those that were not able to be mixed uniformly were marked with an ×. <Viscosity measurement> A B-type viscometer (model: BMII) (manufactured by Toki Sangyo Co., Ltd.) was used to measure the viscosity under the conditions of rotor No. 4, rotation speed (α-gel: 12 rpm, O/W cream: 6 rpm), measurement time 60 seconds, and temperature 25°C.
<pH measurement>
Measurement was carried out using a pH meter, LAQUA pH/ION METER F-72, manufactured by HORIBA Co., Ltd. The measurement temperature was 25°C.
<Storage stability> The samples were stored in an incubator at room temperature, 5°C, and 50°C for one month.
○: No separation or precipitates <Usage sensation> Five expert panelists evaluated the usage sensation. ○: The usage sensation was equal to or better than the sensation when no polymer having a cationic group was blended.
×: The usability is inferior to 〇.
<Preservative effectiveness test>
A preservative effectiveness test of the composition of the present disclosure was conducted according to the method described in the Japanese Pharmacopoeia. Escherichia coli and Staphylococcus aureus were used as target bacteria. The bacterial survival rate was measured 4 hours, 3 days, and 7 days after inoculation.
Antibacterial properties were judged as ◯ (antibacterial) if the bacterial survival rate after 4 hours was 1% or less of the inoculated number of bacteria and the number of bacteria continued to decrease even after 3 and 7 days, and × (not antibacterial) if not.
<XRD measurement>
Device: Smart Lab (Rigaku Corporation)
X-ray source: Cu K-α (1.5405 Å)
Tube voltage: 45 kV
Tube current: 200mA
1 and 3 are charts obtained by XRD (small angle) measurement, and FIGS. 2 and 4 are charts obtained by XRD (wide angle) measurement.

<Raw materials used>
Sunsoft α-C (manufactured by Taiyo Kagaku Co., Ltd.): a mixture of polyglyceryl-5 stearate and glyceryl stearate. Alpha Pure HSG (manufactured by Sanyo Chemical Industries, Ltd.): polyoxyethylene polyoxypropylene cetyl ether (12EO, 2EO).
Kalcol 6850 (Kao Corporation): Cetearyl alcohol (a mixture of cetanol (45-55%) and stearyl alcohol (45-55%))
COSMOCIL CQ (manufactured by Lonza): Polyaminopropyl biguanide, water mixture MERQUAT 550PR (manufactured by Lubrizol): Polyquaternium-7, water mixture CEH (manufactured by Kokyu Alcohol Kogyo Co., Ltd.): Cetyl ethylhexanoate KF-96A-100CS (manufactured by Shin-Etsu Chemical Co., Ltd.): Dimethicone TAISET 50-C (manufactured by Taiyo Kagaku Co., Ltd.): Glyceryl behenate, Polyglyceryl-6 octastearate mixture Sangelose 60L (manufactured by Daido Kasei Kogyo Co., Ltd.): Hydroxypropyl methylcellulose stearoxy ether

[Synthesis Example - Synthesis of Polymer Containing Cationic Groups]
<Synthesis Example 1>
A separable glass flask equipped with a thermometer, a reflux condenser, and a stirrer was charged with 29.4 g of pure water and 100.0 g of 1,3-butanediol (manufactured by KH Neochem Co., Ltd.), and the temperature was raised to 90° C. under stirring. Next, under stirring, into the polymerization reaction system kept at a constant temperature of 80° C., a monomer solution 1 consisting of 60.0 g of 2-(dimethylamino)ethyl methacrylate (N,N-dimethylaminoethyl methacrylate) (manufactured by Kyoeisha Chemical Co., Ltd., hereinafter referred to as DAM), a monomer solution 2 consisting of 40.0 g of ethyl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd., hereinafter referred to as EMA), and an initiator aqueous solution consisting of 18.3 g of a 10% aqueous solution of 2,2′-azobis(2-methylpropionamidine) dihydrochloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., hereinafter referred to as V-50) were each added dropwise from separate dropping nozzles. The dropwise addition of Monomer Solutions 1 and 2 and the aqueous initiator solution began simultaneously, with Monomer Solution 1 being added over 180 minutes, Monomer Solution 2 over 170 minutes, and the aqueous initiator solution over 210 minutes. After all of the dropwise additions were completed, the reaction solution was maintained at 80°C for an additional 30 minutes to mature, and polymerization was completed. Then, 55.2 g of pure water and 205.5 g of 1,3-butanediol were added to obtain Copolymer 1. The solids content of the obtained Copolymer 1 was 19.7%, the pH was 9.0, and the weight average molecular weight was 30,000.
Synthesis Example 2
A separable glass flask equipped with a thermometer, a reflux condenser, and a stirrer was charged with 90.0 g of 1,3-butanediol and 22.6 g of water, and the temperature was raised to 80° C. under stirring. Next, with stirring, into the polymerization reaction system kept at a constant temperature of 80° C., a monomer solution 1 consisting of 117.5 g of DAM, a monomer solution 2 consisting of 13.5 g of EMA, a monomer solution 3 consisting of 23.2 g of an 18% aqueous acrylic acid solution (manufactured by Nippon Shokubai Co., Ltd.), and an aqueous initiator solution consisting of 22.6 g of a 10% aqueous solution of V-50 were each added dropwise from separate dropping nozzles.
The dropwise addition of the monomer solutions 1 and 2 and the aqueous initiator solution was started simultaneously, with the monomer solutions being added over 150 minutes and the aqueous initiator solution being added over 180 minutes. After the entire addition was completed, the reaction solution was maintained at 80°C for an additional 60 minutes to mature the solution. After the polymerization was completed, 53.9 g of pure water was added to obtain copolymer 2. The solids content of the obtained copolymer 2 was 39.3%, the pH was 9.0, and the weight average molecular weight was 38,000.
Synthesis Example 3
Copolymer 3 was obtained by the method described in Synthesis Example 2, except that DAM was changed from 117.5 g to 101.4 g, EMA from 13.5 g to 27.0 g, and 18% acrylic acid aqueous solution from 23.2 g to 37.6 g in Synthesis Example 2. The solids content of the obtained copolymer 3 was 38.0%, the pH was 9.0, and the weight average molecular weight was 31,000.
Synthesis Example 4
Copolymer 4 was obtained by the method described in Synthesis Example 1, except that the amount of DAM was changed from 60.0 g to 80.0 g and the amount of EMA was changed from 40.0 g to 20.0 g of butyl acrylate (manufactured by Kyoeisha Chemical Co., Ltd., hereinafter referred to as BA). The solids content of the obtained copolymer 4 was 34.8%, the pH was 9.0, and the weight average molecular weight was 29,000.

[Production Example - Preparation of α-gel-containing composition]
<Production Example 1>
89.5 parts of ion-exchanged water and 10.0 parts of Sunsoft α-C (Taiyo Kagaku Co., Ltd.) were mixed and stirred at 2500 rpm for 10 minutes with a homomixer (Labo-Lusion, Primix Corporation) while heating to 80°C ± 5°C, and the resulting homogeneously dissolved mixture was cooled to 35°C. Meanwhile, citric acid was added to Copolymer 1 to adjust the pH to 6, preparing an aqueous solution with a solids concentration of 2%. 0.5 parts of the aqueous solution of Copolymer 1 was mixed with the mixture while stirring, to obtain the α-gel composition of Production Example 1.
The results of the XRD (small angle) measurement are shown in Figure 1, and the results of the XRD (wide angle) measurement are shown in Figure 2. The peak half width in the wide angle measurement was 0.39 deg, and the crystallinity was 4.43%.
<Production Example 2>
The α-gel composition of Production Example 2 was prepared in the same manner as Production Example 1, except that Copolymer 1 was changed to Copolymer 2.
<Production Example 3>
The α-gel composition of Production Example 3 was obtained in the same manner as Production Example 1, except that Copolymer 1 was changed to Copolymer 3.
<Production Example 4>
The α-gel composition of Production Example 4 was prepared in the same manner as Production Example 1, except that Copolymer 1 was changed to Copolymer 4.
<Production Example 5>
The α-gel composition of Production Example 5 was prepared in the same manner as in Production Example 1, except that 89.5 g of ion-exchanged water was changed to 89.95 g and 0.5 parts of the copolymer 1 aqueous solution was changed to 0.05 parts of COSMOCIL CQ.
<Production Example 6>
The α-gel composition of Production Example 6 was prepared in the same manner as Production Example 1, except that 89.5 g of ion-exchanged water was changed to 89.9 g and 0.5 parts of the copolymer 1 aqueous solution was changed to 0.1 parts of MERQUAT 550PR.
<Production Example 7>
The α-gel composition of Production 7 was prepared in the same manner as in Production Example 1, except that 89.5 parts of ion-exchanged water was changed to 79.5 parts, 10.0 parts of Sunsoft α-C was replaced with 10.0 g of Alpha Pure HSG (manufactured by Sanyo Chemical Industries, Ltd.), and 10.0 g of Kalcol 6850 (manufactured by Kao Corporation).
The results of the XRD (small angle) measurement are shown in Figure 1, and the results of the XRD (wide angle) measurement are shown in Figure 2. The peak half width in the wide angle measurement was 0.30 deg, and the crystallinity was 6.40%.
<Comparative Production Example 1>
The α-gel of Comparative Production Example 1 was obtained by the method described in Production Example 1, except that 90.0 parts of ion-exchanged water was used and Copolymer 1 was not used.
The results of the XRD (small angle) measurement are shown in Figure 1, and the results of the XRD (wide angle) measurement are shown in Figure 2. The peak half width in the wide angle measurement was 0.37 deg, and the crystallinity was 2.18%.
<Comparative Production Example 2>
The α-gel of Comparative Production Example 2 was obtained by the method described in Production Example 7, except that 80.0 parts of ion-exchanged water was used and Copolymer 1 was not used.
The results of the XRD (small angle) measurement are shown in Figure 1, and the results of the XRD (wide angle) measurement are shown in Figure 2. The peak half width in the wide angle measurement was 0.20 deg, and the crystallinity was 9.01%.

The X-ray diffraction measurement results in Figure 2 show that the composition of Production Example 1 has a sharp peak in the wide-angle region between 21° and 22°, and that the crystalline structure was maintained even after the polymer containing cationic groups of the present disclosure was mixed with the α-gel of Comparative Production Example 1 to form a composition. The composition of Production Example 7 has a sharp peak in the wide-angle region between 21° and 22°, and that the crystalline structure was maintained even after the polymer containing cationic groups of the present disclosure was mixed with the α-gel of Comparative Production Example 2 to form a composition.

Production Examples 1 to 7 and Comparative Production Examples 1 and 2 were evaluated for initial blendability, pH measurement, initial viscosity measurement, and storage stability. The results are shown in Table 1.

As shown in Table 1, Production Examples 1 to 7, which used polymers containing cationic groups, were found to have good compatibility with α-gel and excellent storage stability. Regarding the feel when used, Production Examples 1 to 5 and 7 were the same as α-gel alone, even when a polymer containing cationic groups was blended. Production Example 6 exhibited stringiness, resulting in an undesirable feel when used. This is thought to be due to the high molecular weight of the polymer containing cationic groups.

[Manufacturing Example - Preparation of O/W type cream containing α-gel-containing composition]
<Production Example 8>
(1) 55.9 parts of ion-exchanged water, 10.0 parts of Sunsoft α-C (manufactured by Taiyo Kagaku Co., Ltd.), 5.0 parts of 1,3-butylene glycol-P (manufactured by KH Neochem Co., Ltd.), and 8.0 parts of concentrated cosmetic glycerin (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) are mixed and heated to 80°C ± 5°C with stirring until uniformly dissolved. (2) Olive squalane (manufactured by Kokyu Alcohol Kogyo Co., Ltd.)
9.0 parts of CEH (manufactured by Kokyu Alcohol Kogyo Co., Ltd.), 9.0 parts of KF-96A-100CS (manufactured by Shin-Etsu Chemical Co., Ltd.), and 2.0 parts of TAISET 50-C (manufactured by Taiyo Kagaku Co., Ltd.) were mixed and heated to 80°C ± 5°C with stirring until uniformly dissolved. (3) While (1) was heated to 80°C ± 5°C, it was stirred at 5000 rpm with a homomixer (Labo-Lusion, manufactured by Primix Corporation), and (2) was added in small portions over 5 minutes to emulsify and obtain a uniform mixture, which was then cooled to 35°C. (4) 0.1 parts of an aqueous solution of copolymer 1, which had been adjusted to pH 6 by adding citric acid to copolymer 1 and had a solids concentration of 2%, was mixed with (3) with stirring to obtain an O/W cream of Production Example 7.
The results of the XRD (small angle) measurement are shown in Figure 3, and the results of the XRD (wide angle) measurement are shown in Figure 4. The peak half width in the wide angle measurement was 0.31 deg, and the crystallinity was 4.65%.
<Production Example 9>
An O/W type cream of Production Example 8 was prepared in the same manner as in Production Example 7, except that 55.9 parts of ion-exchanged water was changed to 55.5 parts, and 0.1 parts of the aqueous solution of Copolymer 1 was changed to 0.5 parts of the aqueous solution of Copolymer 1.
<Production Example 10>
An O/W type cream of Production Example 9 was prepared in the same manner as in Production Example 7, except that 55.9 parts of ion-exchanged water was changed to 51 parts, and 0.1 parts of the aqueous solution of Copolymer 1 was changed to 5.0 parts of the aqueous solution of Copolymer 1.
<Production Example 11>
An O/W type cream of Production Example 10 was prepared in the same manner as in Production Example 8, except that 0.5 parts of the aqueous solution of Copolymer 1 was changed to 0.5 parts of the aqueous solution of Copolymer 2.
<Production Example 12>
An O/W type cream of Production Example 11 was prepared in the same manner as in Production Example 8, except that 0.5 parts of the aqueous solution of Copolymer 1 was changed to 0.5 parts of the aqueous solution of Copolymer 3.
<Production Example 13>
An O/W type cream of Production Example 12 was prepared in the same manner as in Production Example 8, except that 0.5 parts of the aqueous solution of Copolymer 1 was changed to 0.5 parts of the aqueous solution of Copolymer 4.
<Production Example 14>
An O/W type cream of Production Example 13 was prepared in the same manner as in Production Example 7, except that 55.9 parts of ion-exchanged water was changed to 55.95 parts, and 0.1 parts of the aqueous solution of Copolymer 1 was changed to 0.05 parts of COSMOCIL CQ.
<Production Example 15>
An O/W type cream of Production Example 14 was prepared in the same manner as in Production Example 7, except that 0.1 parts of the aqueous solution of Copolymer 1 was changed to 0.1 parts of MERQUAT 550PR.
<Comparative Production Example 3>
An O/W type cream of Comparative Production Example 10 was obtained in the same manner as in Production Example 7, except that the amount of ion-exchanged water was changed from 55.9 parts to 55.5 parts, 1.3-butylene glycol-P was changed from 5.0 parts to 6.0 parts, and concentrated glycerin for cosmetics (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) was changed from 8.0 parts to 5.0 parts, and the aqueous solution of Copolymer 1 was not used.
The results of the XRD (small angle) measurement are shown in Figure 3, and the results of the XRD (wide angle) measurement are shown in Figure 4. The peak half width in the wide angle measurement was 0.30 deg, and the crystallinity was 3.34%.

The X-ray diffraction measurement results in Figure 4 show that the O/W cream of Production Example 8 has a sharp peak in the wide-angle region between 21° and 22°, and it is clear that the crystalline structure is maintained even after the polymer containing cationic groups of the present disclosure is mixed with the O/W cream consisting of α-gel of Comparative Production Example 3 to form a composition.

Production Examples 8 to 15 and Comparative Production Example 3 were evaluated for initial blendability, pH measurement, initial viscosity measurement, storage stability, usability, and preservative effectiveness tests. The results are shown in Table 2.

As shown in Table 2, Production Examples 8 to 15, which used polymers containing cationic groups, were found to have good blendability when formulated into O/W creams and also to have excellent storage stability. Regarding the feel when used, Production Examples 8 to 14, even when blended with polymers containing cationic groups, were the same as α-gel alone. Production Example 15 exhibited stringiness, making the feel when used undesirable. This is thought to be due to the high molecular weight of the polymers containing cationic groups.
In the preservative effectiveness test, it was found that Production Examples 8 to 15, which contained a polymer containing a cationic group, had antibacterial properties against both Escherichia coli and Staphylococcus aureus. In the preservative effectiveness test after 3 and 7 days, no increase in the number of bacteria was observed, demonstrating that antibacterial properties were maintained over a long period of time. Since Comparative Production Example 3, which was formulated with only α-gel, had no antibacterial properties, it was found that the polymer containing a cationic group imparted antibacterial properties to α-gel, and also provided excellent storage stability and usability.

[Production Example - Preparation of O/W emulsion containing α-gel-containing composition]
<Production Examples 16 to 21>
An O/W emulsion containing an α-gel-containing composition was prepared with the formulation shown in Table 3.

Using the blending amounts shown in Table 3, O/W emulsions were prepared according to the procedure described below.
(1) Parts A and B were mixed uniformly at 80 to 85°C. (2) Part B was gradually added while stirring Part A, and the mixture was emulsified for about 5 minutes at 5,000 rpm using a homomixer (Labo-Lution, manufactured by Primix Corporation). The mixture was then gradually cooled to 50°C, and Part C, which had been previously mixed uniformly, was added and mixed uniformly. (3) 0.5 parts, 1.0 parts, and 5.0 parts of Part D (a solution of Copolymer 1 or Copolymer 2 prepared by adding citric acid to Copolymer 1 or 2 to adjust the pH to 6 and then adjusting the solids concentration to 2%) were added to (2) and mixed uniformly to prepare the O/W emulsions of Production Examples 16 to 21.
The prepared O/W emulsion had an excellent feel when applied to the skin.

Claims (6)

(a) a polymer containing a cationic group;
(b) an α-gel containing a nonionic surfactant,
the (a) cationic group-containing polymer is a copolymer of a monomer having a cationic group and another monomer not containing a cationic group,
The (a) cationic group-containing polymer contains 30 mass % or more of a monomer having a cationic group based on the total mass of the copolymer,
the (a) cationic group-containing polymer is a polymer containing primary to tertiary amino groups,
The primary to tertiary amino groups are represented by the following formula (1):
(In the formula, R1 and R2 are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms.)
the other monomer is at least one selected from the group consisting of an ester of (meth)acrylic acid and an alcohol which may have a substituent ((meth)acrylate); an unsaturated monocarboxylic acid (salt); an aromatic vinyl monomer; an olefin monomer; an ester of an unsaturated alcohol and a carboxylic acid; a vinyl halide; an alkyl vinyl ether; an addition reaction product of an unsaturated monomer having a cyclic ether-containing group of 2 to 8 carbon atoms and an alcohol having 1 to 20 carbon atoms; an alkylene oxide adduct of an unsaturated alcohol having 2 to 20 carbon atoms and a terminally hydrophobically modified product thereof; and a cyclic vinyl monomer;
The oil-in-water cosmetic composition includes one or more nonionic surfactants having an HLB value of 8 to 16 and one or more nonionic surfactants having an HLB value of 3 to 6, and the proportion of the one or more nonionic surfactants selected from the group consisting of nonionic surfactants having an HLB value of 8 to 16 is 30% by mass to 90% by mass relative to the total mass of the nonionic surfactants. (a) a polymer containing a cationic group, a nonionic surfactant, and water, which has at least one peak in X-ray diffraction at a diffraction angle (2θ) of 20° to 24°, wherein the polymer (a) containing a cationic group is a copolymer of a monomer having a cationic group and another monomer not containing a cationic group;
The (a) cationic group-containing polymer contains 30 mass % or more of a monomer having a cationic group based on the total mass of the copolymer,
the (a) cationic group-containing polymer is a polymer containing primary to tertiary amino groups,
The primary to tertiary amino groups are represented by the following formula (1):
(In the formula, R1 and R2 are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms.)
the other monomer is at least one selected from the group consisting of an ester of (meth)acrylic acid and an alcohol which may have a substituent ((meth)acrylate); an unsaturated monocarboxylic acid (salt); an aromatic vinyl monomer; an olefin monomer; an ester of an unsaturated alcohol and a carboxylic acid; a vinyl halide; an alkyl vinyl ether; an addition reaction product of an unsaturated monomer having a cyclic ether-containing group of 2 to 8 carbon atoms and an alcohol having 1 to 20 carbon atoms; an alkylene oxide adduct of an unsaturated alcohol having 2 to 20 carbon atoms and a terminally hydrophobically modified product thereof; and a cyclic vinyl monomer;
The oil-in-water cosmetic composition includes one or more nonionic surfactants having an HLB value of 8 to 16 and one or more nonionic surfactants having an HLB value of 3 to 6, and the proportion of the one or more nonionic surfactants selected from the group consisting of nonionic surfactants having an HLB value of 8 to 16 is 30% by mass to 90% by mass relative to the total mass of the nonionic surfactants. The O/W cosmetic composition according to claim 1 or 2, wherein the (a) polymer containing a cationic group is present in an amount of 0.0001 parts by mass or more relative to 100% by mass of the α-gel containing the (b) nonionic surfactant. The oil-in-water cosmetic composition according to any one of claims 1 to 3, further comprising an alcohol having a hydrocarbon group having 8 or more carbon atoms. The oil-in-water cosmetic composition according to any one of claims 1 to 4, wherein the nonionic surfactant comprises a polyglycerol fatty acid ester. The oil-in-water cosmetic composition according to any one of claims 1 to 4, wherein the nonionic surfactant comprises a glycerin fatty acid ester.