JP2010254974A - Water-soluble copolymer and cosmetic or external preparation for skin obtained by blending the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-soluble polymer that maintains water retention under low humidity conditions while not giving sticky feeling under high humidity conditions, has little or no viscosity, and does not affect feel or sense from other components. <P>SOLUTION: The water-soluble copolymer is obtained by selecting (meth)acrylic acid as a skeleton component of the polymer, by selecting an amide compound as a group for introduction, and further by using a polymerizable monomer, which gives a water-soluble homopolymer, as a comonomer component and polymerizing the same without using a crosslinking agent. The water-soluble copolymer has very low viscosity while exhibiting excellent water retention and enables realization of sufficient moistness without affecting feel or sense from other components, when blended in cosmetics. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a novel water-soluble copolymer and a cosmetic or skin external preparation containing the same, and more particularly, a novel water-soluble (meth) acrylamide copolymer having water retention and such a water-soluble (meth) acrylamide type. The present invention relates to a cosmetic or an external preparation for skin having excellent moisture retention and containing a copolymer.

Generally, skin dryness occurs when the amount of skin secretions, especially sebum secretion, decreases the stratum corneum barrier function and increases transepidermal water loss. When the skin becomes dry, the gloss of the skin decreases, and harmful effects such as fine wrinkles appear.
Therefore, maintaining the moisture content of the skin is an important issue, and various studies on moisturizing agents for maintaining the moisture content of the skin have been conducted. Hydration with water present in the stratum corneum using water-soluble polyhydric alcohols such as glycerin and 1,3-butylene glycol, organic acid salts such as sodium pyrrolidonecarboxylate and sodium lactate, and polysaccharides such as chitin Although a method for enhancing the effect has been found, these moisturizing effects are often transient and excellent in increasing the moisture content of the skin, but there are still problems with its sustainability. Yes.

  On the other hand, many compounds have been used to improve rheology such as usability and appearance stability by serving as a moisturizer and imparting viscosity. For example, in addition to water-soluble hyaluronic acid characterized by having thickening properties and spinnability, and acetyl hyaluronic acid that has a hydrophobic group and can be blended in an oily base material (see, for example, Patent Document 1), A polymer substance (lipideum) that is said to be excellent in film-forming ability with 2-methacryloyloxyethyl phosphorylcholine having the same structure as the polar group of phosphatidylcholine that focuses on the structure as a constituent unit, for example, a water-soluble amino acid A polymer such as an amino acid-modified γ-polyglutamic acid having an amide bond with an amino group and having moisture retention (for example, see Patent Document 3) has been proposed.

  Further, as a (meth) acrylamide derivative, an N-alkyl or N-alkylene-substituted (meth) acrylamide homopolymer or copolymer is copolymerized with, for example, a crosslinkable monomer having two or more double bonds in the molecule. Separation and retention of water containing a moisture conditioning resin (see, for example, Patent Document 4), a water-soluble gel resin (see, for example, Patent Document 5) or a (meth) acrylamide-derived polymer, which is insoluble in water. Agents (for example, see Patent Document 6), water vapor absorption and release agents (for example, see Patent Document 7), a continuous phase containing a water-immiscible liquid, N-substituted acrylamide and ethylene A polymer composition containing an unsaturated acid or salt (see, for example, Patent Document 8), an acrylamide monomer having an alkyl group on the nitrogen atom of the amide group, and an alkyl ) Non-hydrogel external composition containing a copolymer with an acrylate and an aliphatic alcohol having 1 to 3 carbon atoms (for example, see Patent Document 9), an acrylic acid polymer, a vinyl alcohol polymer, vinyl A water-soluble polymer powder comprising one or more polymers selected from pyrrolidone polymers, acrylamide polymers, N-vinylacetamide polymers, N-mono or dialkylacrylamide polymers (see, for example, Patent Document 10) ) Has been proposed. Furthermore, a thickener (for example, see Patent Document 11) comprising a microgel obtained by dissolving a water-soluble ethylenically unsaturated monomer such as dialkylacrylamide and an ionic acrylamide derivative in a dispersion layer and radical polymerization in the dispersion phase. An oil-in-water nanoemulsion containing an oily phase dispersed in an aqueous solution and containing a neutral acrylic acid homopolymer has been proposed (for example, see Patent Document 12).

Japanese Patent No. 3557044 Japanese Patent No. 2832119 JP 2007-297559 A JP-A-60-250013 JP-A-60-250019 JP-A-60-9010 JP-A-61-263639 Special table 2004-533520 Special table 2007-119428 JP-A-2004-83618 Japanese Patent Laying-Open No. 2005-289831 JP 2002-68935 A

  Conventionally, moisturizers that have high hygroscopicity under high humidity feel sticky, and conversely, under low humidity, water molecules are often released and water retention is not maintained, and even water-soluble polymers are viscous. At the same time, other undesirable characteristics such as spinnability may be imparted, and further imparting viscosity may affect the feel and sensation of other components of the cosmetic. The object of the present invention is to maintain water retention even under low humidity conditions, not to feel sticky even under high humidity conditions, to have little or no viscosity, and to affect the feel and sensation of other components. Is to provide no water-soluble polymer.

  The inventors of theanine (Patent No. 3543478) have been proposed as a moisturizing agent that has a high moisturizing effect, maintains water retention even under low humidity conditions, and has low moisture absorption under high humidity and low stickiness. Paying attention to the acetamide part and examining whether monoethylacetamide can be used as a moisturizing agent, it was confirmed that it has volatility and is difficult to be blended into cosmetics as a moisturizing agent. However, monoethylacetamide was found to interact with water molecules, so (meth) acrylic acid was selected as the polymer backbone, amide compound was selected as the introduction group, and a water-soluble homopolymer was obtained. Water-soluble copolymer obtained by polymerizing without using a cross-linking agent using a water-soluble monomer as a comonomer component exhibits excellent water retention and has a very low viscosity. It has been found that sufficient moisture retention can be realized without affecting the feel and sensuality of other ingredients. In addition, the present inventors have also found that the coexistence of the water-soluble copolymer of the present invention with phospholipids, particularly liposomes formed therefrom, improves the moisturizing effect as compared to the case of phospholipids or liposomes alone. Completed the invention.

  That is, the present invention provides [1] one or more repeating units represented by formula (1) derived from an acrylamide or methacrylamide polymerizable monomer: (A)

(In the formula, R1 represents a hydrogen atom or a methyl group, R2 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R3 represents an alkyl group having 1 to 3 carbon atoms or a hydroxy group having 1 to 3 carbon atoms. An alkyl group) and one or more repeating units derived from a polymerizable monomer that gives a water-soluble homopolymer: (B), and the molar ratio of A: B is 99.98. : 0.02 to 10:90, and a mass reduction rate after standing for 6 hours in a 50% by mass aqueous solution of the polymer at a temperature of 30 ° C. and a relative humidity of 60% is less than 25% by mass Or a water-soluble (meth) acrylamide copolymer for external preparations for skin, [2] and a mass reduction rate of 3% by mass of a 50% by mass aqueous solution of the polymer when the relative humidity is lowered from 60% to 40% at a temperature of 30 ° C. Less than% The water-soluble (meth) acrylamide copolymer for cosmetics or skin external preparations according to the above [1], and [3] Further, when the relative humidity is raised from 40% to 60% at a temperature of 30 ° C., 50 of the polymer A water-soluble (meth) acrylamide copolymer for cosmetics or external preparations for skin according to the above [1] or [2], wherein the mass increase rate of the mass-% aqueous solution is less than 3 mass%, or [4] water-soluble The above [1], wherein one or two or more repeating units derived from a polymerizable monomer giving a homopolymer of (B) is a repeating unit represented by the following formula (2): To [3] water-soluble (meth) acrylamide copolymer for cosmetics or skin external preparation

［式中、Ｒ４は、水素原子又はメチル基、Ｙは、下記一般式（３）〜（６）

[Wherein, R4 is a hydrogen atom or a methyl group, and Y is the following general formula (3) to (6)

(In the formula, R5 is a hydrogen atom, an alkali metal element, an ammonium group, a monovalent group derived from an organic base, a — ((CH ₂ ) pO) qH group (where p is 2 or 3, p When q is 2, q represents any integer of 1 to 10, and when p is 3, q represents any integer of 1 to 3), or-(CH ₂ CH (OH) CH ₂ O ) RH group (wherein r represents any integer of 1 to 10)),

、

,

、又は

Or

Represents. However, when Y is represented by Formula (4) or Formula (5), R4 is a hydrogen atom. ]
About.

  The present invention also provides [5] one or more repeating units represented by formula (1) derived from acrylamide or methacrylamide polymerizable monomer: (A)

(In the formula, R1 represents a hydrogen atom or a methyl group, R2 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R3 represents an alkyl group having 1 to 3 carbon atoms or a hydroxy group having 1 to 3 carbon atoms. Represents an alkyl group),
Following formula (2)

［式中、Ｒ４は、水素原子又はメチル基、Ｙは、下記一般式（３’）、（５）又は（６）

[Wherein R4 is a hydrogen atom or a methyl group, and Y is the following general formula (3 ′), (5) or (6)

（式中、Ｒ５’は、−（（ＣＨ_２）ｐＯ）ｑＨ基（但し、ｐは２又は３であり、ｐが２の場合、ｑは１〜１０のいずれかの整数を表し、ｐが３の場合、ｑは１〜３のいずれかの整数を表す）、−（ＣＨ_２ＣＨ（ＯＨ）ＣＨ_２Ｏ）ｒＨ基（但し、ｒは１〜１０のいずれかの整数を表す）を表す）、

(In the formula, R5 ′ represents a — ((CH ₂ ) pO) qH group (where p is 2 or 3, and when p is 2, q represents an integer of 1 to 10; In the case of 3, q represents any integer of 1 to 3),-(CH ₂ CH (OH) CH ₂ O) rH group (where r represents any integer of 1 to 10). ),

又は、

Or

Represents. However, when Y is represented by Formula (5), R4 is a hydrogen atom. ]
A repeating unit represented by: (B),
The molar ratio of A: B is 99.98: 0.02 to 10:90.
It is related with the water-soluble (meth) acrylamide type copolymer characterized by these.

  The present invention further includes [6] (A) the water-soluble (meth) acrylamide copolymer according to any one of [1] to [5] above, and (B) a phospholipid. A liposome-containing water-soluble (meth) acrylamide copolymer composition, [7] and (C) containing at least one selected from the group consisting of (C) cholesterol, cholesterol derivatives, phytosterols, and phytosterol derivatives. 6] The liposome-containing water-soluble (meth) acrylamide copolymer composition according to [6], and [8] further comprising (D) at least one selected from the group consisting of glycerin and 1,3-butylene glycol. The liposome-containing water-soluble (meth) acrylamide copolymer composition according to [6] or [7] above Or [9] a cosmetic or skin external preparation containing the water-soluble (meth) acrylamide copolymer according to any one of [1] to [5], or [10] of [6] to [8] above. The cosmetic or skin external preparation characterized by including the liposome-containing water-soluble (meth) acrylamide copolymer composition described in any one of the above.

  The water-soluble (meth) acrylamide copolymer of the present invention has a mass reduction rate of less than 25% by mass after standing for 5 hours in a 50% by mass aqueous solution of the polymer at a temperature of 30 ° C. and a relative humidity of 60%. When the relative humidity was lowered from 60% to 40% at 0 ° C., the mass reduction rate of the 50% by weight aqueous solution of the polymer was less than 3% by weight, and the relative humidity was increased from 40% to 60% at a temperature of 30 ° C. When the mass increase rate of the 50% by mass aqueous solution of the polymer is less than 3% by mass, the moisture retention is excellent. By using a water-soluble (meth) acrylamide copolymer having such properties, an oil-in-water emulsion containing an oily phase dispersed in an aqueous phase, compared with the method described in JP-A-2002-68935. Moisturizing properties can be imparted to the blended cosmetics, etc. without blending, and the touch and sensation of other components are less affected.

  Furthermore, when the phospholipid coexists, particularly when the phospholipid forms a liposome, the water-soluble (meth) acrylamide copolymer of the present invention contributes to the improvement of the temporal stability of the liposome. The keratin storage property is enhanced, and the moisturizing effect over time of the skin of the phospholipid and the water-soluble (meth) acrylamide copolymer of the present invention can be remarkably enhanced.

It is a figure which shows the measurement result of the skin moisture content by continuous use about this invention products 9 and 10 and the comparative products 8-10.

(One or more repeating units represented by formula (1) derived from an acrylamide or methacrylamide polymerizable monomer: (A))
In formula (1), R1 represents a hydrogen atom or a methyl group, R2 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R3 represents an alkyl group having 1 to 3 carbon atoms or 1 to 3 carbon atoms. The hydroxyalkyl group of is shown. Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. As the hydroxyalkyl group having 1 to 3 carbon atoms, _-CH 2 OH _group, -CH 2 _CH 2 OH group, -CH (OH) CH _{3 group,} -CH _{2 CH 2} CH ₂ OH group, -CH ₂ CH (OH) CH ₃ group, —CH (OH) CH ₂ CH ₃ group, —CH (OH) ₂ group, —CH (OH) CH ₂ OH group, —CH ₂ CH (OH) CH ₂ OH group, — CH ₂ C (OH) ₂ CH ₃ group, —CH (OH) CH (OH) CH ₂ OH and the like can be exemplified.

  Specific examples of the monomer corresponding to the repeating unit represented by the above formula (1) include N-methylacrylamide, N-ethylacrylamide, N-propylacrylamide, N-isopropylacrylamide, and N, N-dimethyl. Acrylamide, N, N-diethylacrylamide, N, N-di-n-propylacrylamide, N, N-diisopropylacrylamide, N-hydroxymethylacrylamide, N-2-hydroxyethylacrylamide, N-3-hydroxy-n-propylacrylamide Acrylamide-based polymerizable monomers such as N-methyl-N-ethylacrylamide, N-methyl-Nn-propylacrylamide, N-methyl-N-hydroxymethylacrylamide, N-ethyl-N-2-hydroxyethylacrylamide, Or N-methylmethacrylamide, N-ethylmethacrylamide, Nn-propylmethacrylamide, N-isopropylmethacrylamide, N, N-cymethylmethacrylamide, N, N-diethylmethacrylamide, N, N-di-n- Propyl methacrylamide, N, N-diisopropyl methacrylamide, N-hydroxymethyl methacrylamide, N-2-hydroxyethyl methacrylamide, N-3-hydroxy-n-propyl methacrylamide, N-methyl-N-ethyl methacrylamide, Examples thereof include methacrylamide polymerizable monomers such as N-methyl-Nn-propyl methacrylamide, N-methyl-N-hydroxymethyl methacrylamide, and N-ethyl-N-2-hydroxyethyl methacrylamide. These can use 1 type (s) or 2 or more types.

(Repeating unit derived from polymerizable monomer giving water-soluble homopolymer: (B))
The polymerizable monomer corresponding to the repeating unit (B) is not particularly limited as long as it is a polymerizable monomer that can be a water-soluble homopolymer by itself, but for example, the above-described formula (2) A polymerizable monomer corresponding to the repeating unit represented by Preferably, the polymerizable monomer corresponding to the repeating unit represented by the above formula (2) and formula (3) or the above formula (2) and formula (3 ′), the above formula (2) and formula (4) ), A polymerizable monomer corresponding to the repeating unit represented by the above formulas (2) and (5), a formula (2) and a formula (6) The effect of the present invention is further exhibited when the polymerizable monomer corresponding to the repeating unit represented by) is used in the present invention alone or in combination of two or more.

  In said formula (2), R4 is a hydrogen atom or a methyl group, Y represents said formula (3)-(6), Y is represented by said formula (4) or said formula (5). In the case, R4 is a hydrogen atom.

When Y is the above formula (3), in formula (3), R5 is a hydrogen atom, an alkali metal element, an ammonium group, a monovalent group derived from an organic base,-((CH ₂ ) pO) qH Group (however, p is 2 or 3, when p is 2, q represents any integer of 1 to 10, and when p is 3, q represents any integer of 1 to 3) Or — (CH ₂ CH (OH) CH ₂ O) rH group (where r represents an integer of 1 to 10). When Y is the above formula (3 ′), in formula (3 ′), R5 ′ is a — ((CH ₂ ) pO) qH group (provided that p is 2 or 3, and p is 2). In the case, q represents any integer of 1 to 10, and when p is 3, q represents any integer of 1 to 3), or — (CH ₂ CH (OH) CH ₂ O) rH group (Where r represents an integer of 1 to 10). Examples of the alkali metal element include lithium, sodium, and potassium. Examples of the monovalent group derived from an organic base include methylammonium, dimethylammonium, phenylammonium, pyridinium, imidazolium, quinolinium, alkanolamine, and the like. The center heteroatom is a nitrogen atom, the center heteroatom such as trimethylsulfonium or tridodecylsulfonium is the sulfur atom, the center heteroatom such as tetraphenylphosphonium is the phosphorus atom Onium and the like can be exemplified.

Examples of the — ((CH ₂ ) pO—) qH group include a — (CH ₂ ) ₂ OH group, a — ((CH ₂ ) ₂ O) ₂ H group, and a — ((CH ₂ ) ₂ O) ₃ H group. , — ((CH ₂ ) ₂ O) ₅ H group, — ((CH ₂ ) ₂ O) ₁₀ H group, — (CH ₂ ) ₃ OH group, — ((CH ₂ ) ₃ O) ₂ H group, — ((CH ₂ ) ₃ O) ₃ H group and the like can be mentioned, but when the degree of polymerization of propylene glycol exceeds 4, the hydrophilicity of the polymerizable monomer is lowered and represented by formula (1). Even when copolymerized with an acrylamide or methacrylamide polymerizable monomer, the water-solubility of the polymer is lowered and the water retention of the copolymer is poor, so that the water-soluble copolymer targeted by the present invention cannot be obtained. Examples of the — (CH ₂ CH (OH) CH ₂ O) rH group include a —CH ₂ CH (OH) CH ₂ OH group, a — (CH ₂ CH (OH) CH ₂ O) ₂ H group, — _{(CH 2 CH (OH) CH} 2 O) 3 H _{group, - (CH 2 CH (OH} ) CH 2 O) 5 H _{group, - (CH 2 CH (OH} ) CH 2 O) 7 H group, - (CH ₂ CH (OH) CH ₂ O) ₁₀ H group and the like.

  As the polymerizable monomer corresponding to the repeating unit represented by the above formula (2) and formula (3), or formula (2) and formula (3 ′), acrylic acid; sodium acrylate, potassium acrylate Acrylic acid alkali metal salts such as: acrylic acid ammonium salt; acrylic acid tetramethylammonium salt, acrylic acid pyridinium salt, acrylic acid trimethylsulfonium salt and other acrylic acid organic base salts; acrylic acid hydroxyethyl ester, acrylic acid polyethylene glycol ester, acrylic Polyhydric alcohol esters of acrylic acid such as hydroxypropyl ester of acrylic acid, polypropylene glycol acrylate, glycerol acrylate, polyglycerol acrylate; methacrylic acid; sodium methacrylate, potassium methacrylate Methacrylic acid alkali metal salts; ammonium methacrylate; tetramethylammonium methacrylate, pyridinium methacrylate, trimethylsulfonium methacrylate, and other methacrylic acid organic base salts; methacrylic acid hydroxyethyl ester, methacrylic acid polyethylene glycol ester, methacrylic acid Mention may be made of polyhydric alcohol esters of methacrylic acid such as hydroxypropyl ester, methacrylic acid polypropylene glycol ester, methacrylic acid glycerol ester, methacrylic acid polyglycerol ester.

  Examples of the polymerizable monomer corresponding to the repeating units represented by the formulas (2) and (4) include N-vinylpyrrolidone.

  Examples of the polymerizable monomer corresponding to the repeating units represented by the formulas (2) and (5) include N-vinylformamide.

  Examples of the polymerizable monomer corresponding to the repeating units represented by the formulas (2) and (6) include 2- (glucosyloxy) ethyl acrylate or 2- (glucosyloxy) ethyl methacrylate.

(Optional component)
Further, the water-soluble (meth) acrylamide copolymer of the present invention can contain other optional components other than the above-mentioned monomer (monomer) component as a constituent monomer as long as the effects of the present invention are not impaired. . Other optional components are not particularly limited. For example, polymerizable acids such as crotonic acid, isocrotonic acid, itaconic acid, vinyl sulfonic acid, allyl sulfonic acid, amidomethylpropane sulfonic acid, and acid phosphooxyalkyl acrylate. And polymerizable macromonomers such as silicone macromonomer, polyacrylic macromonomer, polyester macromonomer, and polyamide macromonomer, and polymerizable polysaccharides.

(Water-soluble (meth) acrylamide copolymer)
The water-soluble (meth) acrylamide copolymer of the present invention comprises one or more repeating units (A) represented by the formula (1) derived from an acrylamide-based or methacrylamide-based polymerizable monomer, water-soluble 1 or 2 or more types of repeating units (B) derived from a polymerizable monomer that gives a functional homopolymer, and the molar ratio of A: B is 99.98: 0.02 to 10: 90 is preferable, 99.5: 0.5 to 5:95 is more preferable, and 97.5: 2.5 to 10:90 is most preferable. The water-soluble (meth) acrylamide copolymer of the present invention may be a random copolymer, a partial block copolymer, or a block copolymer. The water-soluble (meth) acrylamide copolymer of the present invention is a polymer that does not use a crosslinking agent.

  The weight average molecular weight of the water-soluble (meth) acrylamide copolymer of the present invention is not particularly limited, but liquid gel permeation using a calibration curve and a refractive index detector prepared with a linear polystyrene standard product using tetrahydrofuran as an eluent. The polystyrene equivalent weight average molecular weight (Mw) measured by the chromatography (GPC) method is preferably in the range of 2,000 to 5,000,000, and more preferably in the range of 5,000 to 800,000. preferable. If it exceeds 5,000,000, the dissolution rate will decrease, and there may be inconveniences when used as a solution, the viscosity of the aqueous solution of the water-soluble (meth) acrylamide copolymer will increase, and it will be blended into cosmetics. In some cases, the spreadability may be affected.

  The water-soluble (meth) acrylamide copolymer of the present invention is characterized by being soluble in water. The water-soluble (meth) acrylamide copolymer of the present invention has a mass reduction rate of less than 25% by mass after standing for 5 hours in a 50% by mass aqueous solution of the polymer at a temperature of 30 ° C. and a relative humidity of 60%. When the relative humidity is decreased from 60% to 40% at a temperature of 30 ° C., the mass reduction rate of the 50% by mass aqueous solution of the polymer is less than 3% by mass, and further the relative humidity is decreased from 40% to 60% at a temperature of 30 ° C. The mass increase rate of the 50% by mass aqueous solution of the polymer when it is raised is less than 3% by mass.

In the present invention, the mass change rate (mass increase rate / mass decrease rate) is calculated as follows.
(1) “Mass reduction rate after standing for 6 hours of 50% by weight aqueous solution of the polymer at a temperature of 30 ° C. and a relative humidity of 60%” consists of a 50% by weight aqueous solution of the water-soluble (meth) acrylamide copolymer of the present invention. This is obtained by preparing a sample, measuring the mass, placing it in a constant temperature and humidity chamber having a temperature of 30 ° C. and a humidity of 60%, leaving it for 6 hours, measuring the mass again, and calculating the decrease in mass.
(2) “Mass reduction rate of 50% by mass aqueous solution of the polymer when the relative humidity is lowered from 60% to 40% at 30 ° C.” is 50% by mass of the water-soluble (meth) acrylamide homopolymer of the present invention. Prepare a sample consisting of an aqueous solution, put it in a constant temperature and humidity chamber at 30 ° C. and 60% humidity, measure the mass after 48 hours, and then place the sample in a constant temperature and humidity chamber at 30 ° C. and humidity 40%. It is calculated | required by measuring the mass after 6 hours, and calculating the increase in mass.
(3) “Mass increase rate of 50% by mass aqueous solution of the polymer when the relative humidity is increased from 40% to 60% at a temperature of 30 ° C.” is 50% by mass of the water-soluble (meth) acrylamide homopolymer of the present invention. Prepare a sample consisting of an aqueous solution, put it in a constant temperature and humidity chamber at 30 ° C and 60% humidity, and after 48 hours, transfer the sample to a constant temperature and humidity chamber at 30 ° C and 40% humidity. Then, the sample is transferred to a constant temperature and humidity chamber having a temperature of 30 ° C. and a humidity of 60%, the mass after 6 hours is measured, and the increase in mass is calculated.

[Production method]
The method for producing an acrylamide or methacrylamide polymerizable monomer corresponding to the repeating unit represented by the above formula (1) is not particularly limited including a known method. For example, the amine is dissolved in acetonitrile. Then, after adding triethylamine as appropriate, the mixture was cooled, and while maintaining 0 ° C., a known method such as a chemical method such as a method of slowly dropping acrylic acid chloride or methacrylic acid chloride under stirring and concentrating under reduced pressure was included. A synthesis method can be mentioned, and the product may be purified by a purification means including known methods such as recrystallization and column chromatography.

  In addition, as a method of producing the water-soluble (meth) acrylamide copolymer of the present invention using the acrylamide or methacrylamide polymerizable monomer, one kind of the acrylamide or methacrylamide polymerizable monomer (monomer) or Two or more kinds and a polymerizable monomer that gives the water-soluble homopolymer, for example, one or more kinds of polymerizable monomers represented by the formula (2) and other optional components as constituent monomers Use is not particularly limited as long as the water-soluble (meth) acrylamide copolymer of the present invention having the above characteristics can be produced, and examples thereof include a radical polymerization method, an anionic polymerization method, and a cationic polymerization method. Among them, a radical polymerization method using a radical generator such as a peroxide or an azo compound can be suitably shown, and the amount of such radical generator used , Based on the total amount of the monomers, 0.01 to 10 wt%, preferably from 0.1 to 8 wt%. The form of the copolymer (polymer) may be either a random copolymer or a block copolymer. By adjusting the addition time of the polymerizable monomer of the above formula (2), the random copolymer may be used. A form such as a polymer, a partial block copolymer, and a block copolymer can be selected. As the radical polymerization method, any of known bulk polymerization, emulsion polymerization, solution polymerization and the like can be used. However, in the production method for obtaining a water-soluble (meth) acrylamide copolymer in the present invention, solution polymerization is preferable. Examples of the method for performing the solution polymerization include a method for performing the polymerization reaction under an atmosphere of an inert gas such as nitrogen or argon at a temperature of 50 to 100 ° C, preferably 65 to 75 ° C. In addition, as the organic solvent in the case of performing the above solution polymerization, aromatic hydrocarbons such as toluene, benzene and xylene, esters such as ethyl acetate and butyl acetate, ethers such as dioxane, methyl ethyl ketone and methyl isobutyl Examples include ketones such as ketone and cyclohexanone, alcohols such as ethanol and isopropyl alcohol, and alicyclic hydrocarbons such as cyclohexane.

  Moreover, as another method for producing the water-soluble (meth) acrylamide copolymer of the present invention, one or two kinds of acrylic acid and / or methacrylic acid and a polymerizable monomer represented by the above formula (2) are used. After copolymerizing the above, a method of reacting a carboxyl group of acrylic acid or methacrylic acid with an alkylamine to form an amide can also be employed.

(Cosmetics and skin preparations)
The water-soluble (meth) acrylamide copolymer of the present invention is used as an additive for paints and inks, as a liquid-absorbing material such as sanitary products, as well as for cosmetics and skin external preparations, as a paper additive, paste, food Although it can be used for various uses, such as an additive for skin care, it is preferable to use for cosmetics and a skin external preparation, and it is more preferable to mix | blend with cosmetics. Cosmetics according to the present invention include basic cosmetics such as lotions, creams, milky lotions, and beauty essences, hair cosmetics such as shampoos, rinses, and treatments, makeup cosmetics such as liquid foundations, base emulsions, and tanning. Cosmetics such as stop cosmetics (including quasi-drugs) can be exemplified, and examples of external skin preparations include external medicines such as liniments, lotions and ointments.

  The blending ratio of the water-soluble (meth) acrylamide copolymer of the present invention to the cosmetic or external skin preparation of the present invention is not particularly limited as long as the effects of the present invention are exhibited. 0.01-10 mass% is preferable with respect to the whole agent, and 0.5-5 mass% is more preferable.

  The cosmetics and skin external preparations of the present invention include components generally used in cosmetics and skin external preparations together with the water-soluble (meth) acrylamide copolymer of the present invention, such as the following oily components, surfactants, alcohols 1 type or 2 types or more of humectants, moisturizers, gelling agents, powders, UV absorbers, antiseptics, antibacterial agents, antioxidants, pH adjusters, skin beautifying ingredients, perfumes, etc. You may mix | blend suitably in the range which does not impair the effect of a meth) acrylamide type copolymer.

  Examples of the oil component include hydrocarbon oil, ester oil, glyceride oil, silicone oil, higher alcohol, fatty acid, lanolin and the like. Examples of the surfactant include an anionic surfactant, a cationic surfactant, a nonionic surfactant, and an amphoteric surfactant.

  Examples of the alcohols include lower alcohols such as ethanol and isopropanol, and various alcohols such as glycerin, diglycerin, polyglycerin, diethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 1,3-butylene glycol, and erythritol. Examples thereof include monohydric alcohols, sugar alcohols such as sorbitol, maltose, xylitol, and maltitol, and sterols such as cholesterol, sitosterol, phytosterol, and lanosterol. Examples of the humectant include urea, hyaluronic acid, chondroitin sulfate, pyrrolidone carboxylate and the like.

  The gelling agent is not particularly limited as long as it is an aqueous gelling agent or an oily gelling agent generally used in cosmetics. For example, as the aqueous gelling agent, gum arabic, gum tragacanth, galactan, carob gum, guar gum, Plant polymers such as caraya gum, carrageenan, pectin, agar, quince seed (derived from quince seeds), starch (derived from rice, corn, potato, wheat, etc.), algae colloid, tant gum, locust bean gum, xanthan gum, dextran , Microbial polymers such as succinoglucan and pullulan, animal polymers such as collagen, casein, albumin and gelatin, starch polymers such as carboxymethyl starch and methylhydroxypropyl starch, methylcellulose and hydroxypropyl Cellulose polymers such as cellulose, carboxymethylcellulose, hydroxymethylcellulose, hydroxypropylcellulose, sodium cellulose sulfate, sodium carboxymethylcellulose, alginic acid polymers such as sodium alginate and propylene glycol alginate, sodium polyacrylate, carboxyvinyl Polymers, alkyl-modified carboxyvinyl polymers, vinyl polymers such as polyacrylamide, polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, ethylene oxide propylene oxide copolymer, bentonite, aluminum magnesium silicate, laponite, hectorite, silicic anhydride Inorganic gelling agent thickeners such as oily gelling agent and the like Metal soaps such as aluminum stearate, magnesium stearate, zinc myristate, amino acid derivatives such as N-lauroyl-L-glutamic acid, α, γ-di-n-butylamine, dextrin palmitate, dextrin stearin Dextrin such as acid ester, dextrin 2-ethylhexanoic acid palmitic acid mixed ester, sucrose fatty acid ester such as fatty acid ester, sucrose palmitic acid ester, sucrose stearate ester, sorbitol such as monobenzylidene sorbitol, dibenzylidene sorbitol And organically modified clay minerals such as dimethylbenzyl dodecyl ammonium montmorillonite clay and dimethyl dioctadecyl ammonium montmorillonite clay Door can be.

  Examples of the powder include inorganic powders, organic powders, metal soap powders, colored pigments, pearl pigments, metal powders, tar dyes, natural dyes, and the like, and their particle shapes (spherical, needle-like, Plate shape, etc.), particle diameter (smoke, fine particles, pigment grade, etc.) and particle structure (porous, non-porous, etc.). These powders may be used as they are, but a composite of two or more powders may be used, and surface treatment may be performed with an oil agent, a silicone compound, a fluorine compound, or the like.

  Examples of the ultraviolet absorber include benzoic acid ultraviolet absorbers such as paraaminobenzoic acid, anthranilic acid ultraviolet absorbers such as methyl anthranilate, salicylic acid ultraviolet absorbers such as methyl salicylate, and paramethoxy cinnamon. Examples thereof include cinnamic acid UV absorbers such as octyl acid, benzophenone UV absorbers such as 2,4-dihydroxybenzophenone, and urocanic acid UV absorbers such as ethyl urocanate. Examples of antiseptics and antibacterial agents include paraoxybenzoic acid esters, benzoic acid, sodium benzoate, sorbic acid, potassium sorbate, phenoxyethanol, salicylic acid, coalic acid, sorbic acid, parachlormetacresol, hexachlorophene, benzalkonium chloride Chlorohexidine chloride, trichlorocarbanilide, photosensitizer, isopropylmethylphenol, and the like.

  Examples of the antioxidant include tocopherol, butylhydroxyanisole, dibutylhydroxytoluene and the like. Examples of the pH adjuster include lactic acid, lactate, citric acid, citrate, glycolic acid, succinic acid, tartaric acid, malic acid, potassium carbonate, sodium bicarbonate, ammonium bicarbonate and the like.

  Examples of the above skin beautifying agent include whitening agents such as arbutin, glutathione, and yukinoshita extract, cell activators and rough skin improving agents such as royal jelly, photosensitizer, cholesterol derivatives, and calf blood extract, and nonyl acid wallenyl amide. Nicotinic acid benzyl ester, nicotinic acid β-butoxyethyl ester, capsaicin, zingerone, cantalis tincture, ictamol, caffeine, tannic acid, α-borneol, nicotinic acid tocopherol, inositol hexanicotinate, cyclandrate, cinnarizine, trazoline , Blood circulation promoters such as acetylcholine, verapamil, cephalanthin, and γ-oryzanol; skin astringents such as zinc oxide and tannic acid; and antiseborrheic agents such as sulfur and thianthol.

  Although it does not specifically limit as a dosage form of the cosmetics and skin external preparation of this invention, Aqueous, an oil-in-water type, a water-in-oil type etc. can be mentioned. In addition, examples of the form of the cosmetic and the external preparation for skin of the present invention include cream, gel, liquid and the like, and the effects of the present invention are most effective in lotions, creams, emulsions, beauty Basic cosmetics such as liquids, hair cosmetics such as shampoos, rinses and treatments, liquid foundations, base emulsions and the like.

(Liposome-containing water-soluble (meth) acrylamide copolymer composition)
In addition, the water-soluble (meth) acrylamide copolymer of the present invention can improve the moisturizing effect when used in combination with phospholipids. In particular, the coexistence of liposomes formed from phospholipids further improves the moisturizing effect. Can be made.

  Liposomes, which are closed vesicles composed of phospholipid bilayers, have been used for research as biological membrane models and have been applied to pharmaceuticals and cosmetics as microcapsules that encapsulate and deliver drugs for a long time. Particularly in the cosmetics field, when liposomes are applied to the skin, a high moisturizing effect can be obtained because the liposomes have the property of staying in the stratum corneum for a long time.

  The liposome-containing water-soluble (meth) acrylamide copolymer composition of the present invention contains, in an aqueous solution such as purified water, the water-soluble (meth) acrylamide copolymer of the present invention and at least a phospholipid, preferably further Or at least one selected from the group consisting of cholesterol, cholesterol derivatives, phytosterols and phytosterol derivatives, and / or at least one selected from the group consisting of glycerol and 1,3-butylene glycol.

  Examples of phospholipids include natural phospholipids such as phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, lysophosphatidylcholine, sphingomyelin, egg yolk lecithin, soybean lecithin, dioleoylphosphatidylcholine, and other natural phospholipids. Examples include hydrogenated phospholipids in which unsaturated carbon chains of phospholipids are saturated with hydrogen, and other phospholipids extracted from microorganisms such as Escherichia coli. These can be used alone or in combination of two or more. Among these, one or more selected from hydrogenated soybean phospholipid, hydrogenated egg yolk phospholipid, hydrogenated phosphatidylcholine, and hydrogenated phosphatidylserine are preferable.

  Examples of cholesterol or cholesterol derivatives include cholesteryl hydroxystearate, cholesterol, cholestanol, dehydrocholesterol, lanolin fatty acid cholesteryl, isostearic acid cholesteryl, ricinoleic acid cholesteryl, macadamia nut oil fatty acid cholesteryl, and the like. Can be used in combination.

  Examples of phytosterol or phytosterol induction include β-sitosterol, stigmasterol, campesterol, ergosterol, macadamia nut fatty acid phytosteryl, phytosteryl oleate, and the like, and these can be used alone or in combination.

  The liposome-containing water-soluble (meth) acrylamide copolymer composition of the present invention can be produced according to a known method for producing a liposome-containing aqueous dispersion, except that the water-soluble (meth) acrylamide copolymer of the present invention coexists. For example, it can be produced by a known method such as a bangham method, a pH gradient method, a freeze-thaw method, a reverse phase evaporation method, a mechanochemical method, a supercritical carbon dioxide method, or a film loading method (Japanese Patent Application Laid-Open No. 8-183726). Etc.)

  Although the compounding quantity of each component in a composition can be suitably set according to a use, the following ranges are preferable. The water-soluble (meth) acrylamide copolymer of the present invention is 0.01 to 10% by mass, more preferably 0.1 to 5% by mass. A phospholipid is 0.005-10 mass%, More preferably, it is 0.01-5 mass%. Outside this range, the temporal stability when liposomes are formed is not preferred. Cholesterol, cholesterol derivative, phytosterol or phytosterol derivative is not always necessary, but when used, it is 0.001 to 5% by mass, preferably 0.005 to 3% by mass. Glycerin or 1,3-butylene glycol is not always necessary, but when used, it is 1 to 50% by mass, preferably 5 to 40% by mass.

  Hereinafter, the present invention will be described with reference to examples. In addition, these do not limit this invention at all.

(Reference Example 1)
[Synthesis of N-ethylacrylamide]
15 g of ethylamine (NH ₂ (CH ₂ CH ₃ ): 45.1) was dissolved in 250 mL of acetonitrile, 26 g of triethylamine (N (CH ₂ CH ₃ ) ₃ : 77.2) was added, and the mixture was cooled to 0 ° C. While maintaining 0 ° C., 30 g of acrylic acid chloride (CH ₂ CHCOCl: 90.51) was slowly added dropwise thereto with stirring. After completion of the dropwise addition, the cooling was released, and when the liquid temperature became the same as the room temperature, the stirring was stopped and the solution was concentrated under reduced pressure. 200 mL of purified water and 20 g of sodium chloride were added to the concentrate, adjusted to pH 6.5 with 1N hydrochloric acid, and partitioned with ethyl acetate. The aqueous layer after ethyl acetate partitioning was further added with 10 g of sodium chloride and partitioned with ethyl acetate. The ethyl acetate partition was dried over anhydrous sodium sulfate and then concentrated under reduced pressure to obtain about 25.5 g of a crude reaction product. This crude reaction product was developed by column chromatography (support: ODS silica gel, developing solvent: water: methanol (9: 1)), purified, and N-ethylacrylamide (CH ₂ CHCONH (CH ₂ CH ₃ ): 99. .15) 22.8 g (yield approximately 69%) was obtained. The obtained N-ethylacrylamide had an elemental analysis value of carbon 58.58%, hydrogen 9.15%, nitrogen 14.13%, oxygen 16.14% (calculated residue), (theoretical value: carbon 60.58). %, Hydrogen 9.151%, nitrogen 14.129%, oxygen 16.139%), H-NMR (in deuterated chloroform solution), δ = 6.7 (1H, b), 6.2 (2H, m ), 5.6 (1H, dd), 3.3 (2H, qq), 1.1 (3H, m). In C-NMR (in deuterated chloroform solution), δ = 165.6 (166.7), 131.1 (131.1), 125.7 (128.9), 34.3 (34.1) 14.5 (15.0). (Numerical values in parentheses are theoretical values) In mass spectrometry, a peak (theoretical value: 99.13) of m / e = 99.07 (M +) was observed.

(Reference Example 2)
[Synthesis of N-hydroxyethyl methacrylamide]
Hydroxyethylamine (NH ₂ (CH ₂ CH ₂ OH): 61.1) 20.4 g instead of ethylamine, methacrylic acid chloride (CH ₂ C (CH ₃ ) COCl: 104.54) instead of acrylic acid chloride 34. The same treatment as in Reference Example 1 was carried out except that 8 g was used, and 29.1 g (yield 67) of N-hydroxyethyl methacrylamide (CH ₂ C (CH ₃ ) CONH (CH ₂ CH ₂ OH): 129.18). .6%).

[Synthesis of copolymer of N-ethylacrylamide and acrylic acid]
A 300 mL three-necked flask (reaction vessel) was provided with a nitrogen introduction tube, a thermometer, and a cooling tube, and 30 g of isopropyl alcohol was added to replace the atmosphere with nitrogen. In this, 5.79 g of N-ethylacrylamide obtained in Reference Example 1 and 4.21 g of acrylic acid (a reagent manufactured by Tokyo Chemical Industry Co., Ltd.) were dissolved, and further, N, N-azobisisobutyronitrile (manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved. Reagent) 0.1 g was added. The reaction vessel was heated to 70 ° C. and reacted for 3 hours. After cooling, the reaction solution was poured into n-hexane, and the precipitated white solid was collected and dissolved in 10 g of isopropyl alcohol. This was again poured into n-hexane, and the precipitated white solid was collected and dried to obtain 9.74 g (yield 97.4%) of a copolymer composed of N-ethylacrylamide and acrylic acid. The obtained copolymer had a polystyrene-reduced weight average molecular weight of 25,600 by GPC. The copolymer consisting of N-ethylacrylamide and acrylic acid was transparently dissolved in water.

[Synthesis of copolymer of N-ethylacrylamide and acrylic acid]
The same treatment as in Example 1 was performed except that 0.02 g of N, N-azobisisobutyronitrile was used, and 9.87 g of a copolymer of N-ethylacrylamide and acrylic acid (yield 98.7%). Got. The weight average molecular weight in terms of polystyrene by GPC of the obtained copolymer was 34,600. This copolymer of N-ethylacrylamide and acrylic acid was transparently dissolved in water.

[Synthesis of copolymer of N, N-diethylacrylamide and acrylic acid]
The same treatment as in Example 1 was performed except that 6.38 g of N, N-diethylacrylamide (a reagent manufactured by Tokyo Chemical Industry Co., Ltd.), 3.62 g of acrylic acid, and 0.02 g of N, N-azobisisobutyronitrile were used. , 9.81 g (yield 98.1%) of a copolymer consisting of N, N-diethylacrylamide and acrylic acid was obtained. The obtained copolymer had a polystyrene-reduced weight average molecular weight of 29,500 by GPC. The copolymer consisting of N, N-diethylacrylamide and acrylic acid was transparently dissolved in water.

[Synthesis of copolymer of N-hydroxyethyl methacrylamide and acrylic acid]
A copolymer of N-hydroxyethylmethacrylamide and acrylic acid was treated in the same manner as in Example 1 except that 6.42 g of N-hydroxyethylmethacrylamide obtained in Reference Example 2 and 3.58 g of acrylic acid were used. 7.08 g (yield 70.8%) was obtained. The obtained copolymer had a polystyrene-reduced weight average molecular weight by GPC of 8,300. This copolymer of N-hydroxyethyl methacrylamide and acrylic acid was transparently dissolved in water.

[Synthesis of copolymer of N-isopropylacrylamide and acrylic acid]
The same treatment as in Example 1 was performed except that 6.11 g of N-isopropylacrylamide (reagent manufactured by Tokyo Chemical Industry Co., Ltd.) and 3.89 g of acrylic acid were used, and 8.18 g of a copolymer consisting of N-isopropylacrylamide and acrylic acid. (Yield 81.8%) was obtained. The weight average molecular weight in terms of polystyrene of the obtained copolymer by GPC was 148,700. The copolymer consisting of N-isopropylacrylamide and acrylic acid was transparently dissolved in water.

[Synthesis of copolymer of N-ethylacrylamide and N-vinylpyrrolidone]
The same treatment as in Example 1 was performed except that 5.1 g of N-ethylacrylamide and 4.9 g of N-vinylpyrrolidone obtained in Reference Example 1 were used, and a co-polymer consisting of N-ethylacrylamide and N-vinylpyrrolidone. 7.23 g (yield 72.3%) of the combined product was obtained. The obtained copolymer had a polystyrene-reduced weight average molecular weight by GPC of 28,700. The copolymer consisting of N-ethylacrylamide and N-vinylpyrrolidone was transparently dissolved in water.

[N-ethylacrylamide and 2- (glucosyloxy) ethyl methacrylate 5.04 g of N-ethylacrylamide obtained in Reference Example 1, 2- (synthesis of glucosi copolymer] ruoxy) ethyl methacrylate (C ₁₂ H ₂₀ O ₈ : 292.3 (manufactured by Nippon Seika Co., Ltd.) The same treatment as in Example 1 was carried out except that 4.96 g was used, and a copolymer of N-ethylacrylamide and 2- (glucosyloxy) ethyl methacrylate (3: 1) The molar ratio was 8.48 g (yield 84.8%). The obtained copolymer had a polystyrene-reduced weight average molecular weight of 87,700 by GPC. This copolymer of N-ethylacrylamide and 2- (glucosyloxy) ethyl methacrylate was dissolved in water transparently.

[Synthesis of copolymer of N-ethylacrylamide and acrylic acid]
7.2 g of polyacrylic acid (molecular weight 5000, manufactured by Wako Pure Chemical Industries, Ltd.), 100 mL of distilled tetrahydrofuran, and 20 g of activated molecular sieve (3A 1/8) are charged into a glass-lined pressure-resistant reaction vessel having an internal volume of 500 mL. A gas introduction valve was installed. From the gas introduction valve, ethylamine gas (manufactured by Tokyo Chemical Industry Co., Ltd.) was press-fitted until the total mass increased by 2.25 g and sealed. Thereafter, the reaction vessel itself was heated to 105 ° C. while shaking and reacted for 6 hours. After the reaction, return to normal temperature, release the pressure, filter the molecular sieve, concentrate under reduced pressure until it is about half volume, inject ethyl acetate to precipitate, filter the precipitate, and vacuum dry. 7.3 g (yield 85.4%) of a copolymer of N-ethylacrylamide and acrylic acid was obtained. The weight average molecular weight of the obtained copolymer in terms of polystyrene by GPC was 6,100. This copolymer of N-ethylacrylamide and acrylic acid dissolved in water transparently, and became a viscous solution.

[Synthesis of copolymer of N-ethylacrylamide and acrylic acid]
A 500 mL three-necked separable flask equipped with a reflux condenser, a thermometer and a stirrer was subjected to activation treatment with 7.2 g of polyacrylic acid (molecular weight 25000, manufactured by Wako Pure Chemical Industries, Ltd.), 150 mL of distilled tetrahydrofuran. After adding 10 g of molecular sieve (3A 1/8) and heating to dissolve polyacrylic acid in tetrahydrofuran, 2.9 g of 1,3-diethylurea (manufactured by Tokyo Chemical Industry Co., Ltd.) was added, and the boiling point of tetrahydrofuran At reflux for 24 hours. After cooling, the molecular sieve is filtered off and concentrated under reduced pressure to about half volume. Then, ethyl acetate is injected to precipitate the precipitate, and the precipitate is filtered off and dried under vacuum to obtain a mixture of N-ethylacrylamide and acrylic acid. 7.00 g (yield 79.5%) of polymer was obtained. The obtained copolymer had a weight average molecular weight in terms of polystyrene by GPC of 30,000. This copolymer of N-ethylacrylamide and acrylic acid dissolved in water transparently, and became a viscous solution.

[Synthesis of N-ethylacrylamide and N-vinylpyrrolidone copolymer]
In a four-necked flask with an internal volume of 300 mL equipped with a reflux condenser, thermometer, nitrogen inlet tube, and stirring device, 14.4 g of acrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), N-vinylpyrrolidone (manufactured by Tokyo Chemical Industry Co., Ltd.) 22.2 g, 200 mL of toluene, and 0.3 g of N, N-azobisisobutyronitrile were weighed. After thoroughly replacing the inside of the flask with nitrogen gas, the temperature was raised with stirring, and the reaction was carried out at 110 ° C. for 3 hours. Acrylic acid and N-vinylpyrrolidone were copolymerized. After the reaction, the mixture was cooled to room temperature, toluene was distilled off under reduced pressure until the total amount was reduced to half, and 10 L of hexane was added to precipitate a copolymer. The precipitated copolymer was collected and dissolved in methanol, followed by a purification step of adding hexane to precipitate the copolymer twice. The copolymer was then dried, and acrylic acid and N-vinylpyrrolidone were mixed. 30.9 g of copolymer was obtained. 18.3 g of this copolymer was weighed into a glass-lined pressure-resistant reaction vessel having an internal volume of 500 mL, 150 mL of distilled tetrahydrofuran and 30 g of activated molecular sieve (3A 1/8) were added, and a gas introduction valve was installed. . From the gas introduction valve, ethylamine gas (manufactured by Tokyo Chemical Industry Co., Ltd.) was press-fitted until the total mass increased by 4.7 g and sealed. Thereafter, the reaction vessel itself was heated to 105 ° C. while shaking and reacted for 6 hours. After the reaction, after returning to normal temperature and releasing the pressure, the molecular sieve is filtered off and concentrated under reduced pressure until it is about half volume, then hexane is injected for precipitation, the precipitate is filtered off, vacuum dried and N -19.8 g (yield 94.3%) of a copolymer of ethylacrylamide and N-vinylpyrrolidone was obtained. The obtained copolymer had a weight average molecular weight of 50,000 in terms of polystyrene by GPC. This copolymer of N-ethylacrylamide and N-vinylpyrrolidone was transparently dissolved in water and became a viscous solution.

[Water retention evaluation 1 (mass reduction test)]
The water-soluble (meth) acrylamide copolymer of the present invention prepared in Examples 1 to 4 and Examples 6 to 7, and glycerin, PCA sodium, sodium lactate, serine, glutamine, 1 g each as a comparative example, each having a diameter Each sample was added to 1 g of purified water in a container of 25 mm height and 10 mm to prepare 50 mass% aqueous solution samples, which were used as test samples in a constant temperature and humidity chamber set at a temperature of 30 ° C. and a relative humidity of 60% for 6 hours. The water retention was evaluated by measuring the mass change. The results obtained here are shown in Table 1.

[result]
Glycerin, PCA sodium, sodium lactate, serine, and glutamine, which are said to have high water retention, were shown to rapidly evaporate under conditions of a temperature of 30 ° C. and a relative humidity of 60%. On the other hand, the polymers produced in Examples 1 to 4 and Examples 6 to 7 have a small mass change, have excellent water retention, and can impart moisture retention when blended in cosmetics. It is estimated to be.

[Water retention evaluation 2 (humidity dependency test)]
Poly (N-ethylacrylamide-acrylic acid), poly (N, N-dimethylacrylamide-acrylic acid), poly (N, N-diethylacrylamide) prepared in Examples 1 to 4 and Examples 6 to 7 above. -Acrylic acid), poly (N-hydroxyethylacrylamide-acrylic acid), poly (N-ethylacrylamide-2- (glucosyloxy) ethyl methacrylate), poly (N-ethylacrylamide-N-vinylpyrrolidone), 1 g each. Each sample was added to 1 g of purified water in a container having a diameter of 25 mm and a height of 10 mm to prepare a 50% by mass aqueous solution sample of each polymer, transferred to a constant temperature and humidity chamber at a temperature of 30 ° C. and a relative humidity of 60%. The mass was measured. The sample was transferred to a constant temperature and humidity chamber with a relative humidity of 40% and the mass after 6 hours was measured to evaluate the rate of mass change when the relative humidity was changed from 60% to 40%. In addition, the mass was measured 24 hours after the sample was transferred to a constant temperature and humidity chamber with a temperature of 30 ° C. and a relative humidity of 40%, and further transferred to a constant temperature and humidity chamber with a relative humidity of 60% and the mass after 6 hours was measured. Then, the mass change rate when the relative humidity was changed from 40% to 60% was evaluated. Water retention was evaluated from each mass change rate. Further, with respect to glycerin, sodium PCA, sodium lactate, serine, glutamine as comparative compounds and theanine as a positive control, 50 mass% aqueous solution samples of each polymer were evaluated in the same manner.

[result]
Regarding the mass change when the relative humidity is changed from 60% to 40%, 50% by mass aqueous solution samples of the polymers prepared in Examples 1 to 4 and Examples 6 to 7 are at most 2.0% or less. Decrease in glycerin, sodium PCA, and sodium lactate showed a decrease of 2% or more. Furthermore, about the mass change after 6 hours when changing the relative humidity from 40% to 60% in the 50% by mass aqueous solution sample of each polymer, the polymers prepared in Examples 1 to 4 and Examples 6 to 7 were used. The 50% by weight aqueous solution sample was not expected to cause stickiness even when blended in cosmetics and the like, while glycerin, sodium PCA and sodium lactate All of them showed an increase in mass, and it was speculated that moisture would be taken in particularly under high humidity conditions, and that it would feel sticky when blended into cosmetics and the like due to such hygroscopicity.

[Viscosity evaluation]
A 10% by mass solution of poly (N-ethylacrylamide-acrylic acid) of Example 1 was prepared and left in a constant temperature bath at 30 ° C. for 24 hours using a single cylinder rotary viscometer (manufactured by Shibaura System Co., Ltd.) The measurement was carried out under the conditions of the viscosity value after 6 revolutions per minute with a No. 3 rotor.
[result]
It was in a state of no viscosity at all.

[Skin lotion sensory evaluation]
A lotion was prepared according to the formulation shown in Table 2 using the polymers prepared in Example 1 and Example 3, and sensory evaluation was performed. A lotion was prepared in the same manner as described above except that a (alkyl acrylate / octylacrylamide) copolymer and carboxyvinyl polymer were used, and sensory evaluation was performed for comparison. The results are shown in Table 2.

Evaluation was performed by the following method.
(Evaluation methods)
Inventive products 1 to 3 and comparative products 1 and 2 are subjected to a use test by a professional panel by 20 people, and evaluated according to the following criteria with respect to “goodness of skin familiarity” when the sample is applied to the skin. Judged by point.
(Evaluation item)
a. Unsatisfactory skin familiarity (absolute evaluation criteria)
(Score): (Evaluation)
6: Very well-familiar 5: Well-familiar 4: Somewhat familiar to the skin 3: Normal 2: Somewhat familiar to the skin 1: Badly familiar to the skin 0: Very poorly familiar to the skin (Criteria)
(Judgment): (Average score)
: Over 5 points (very good)
○: 5 points or less exceeding 3.5 points (good)
Δ: 3 points or less exceeding 1.5 points (slightly poor)
×: 1.5 points or less (defect)

(Evaluation methods)
About this invention products 1-3 and comparative products 1-2, use test is done by a professional panel by 20 people, and the "moist feeling" when the sample is applied to the skin is evaluated according to the following criteria, and the average score Judged.
(Evaluation item)
b. Moist feeling (absolute evaluation criteria)
(Score): (Evaluation)
6: Feels moist 5: Moist )
(Judgment): (Average score)
: Over 5 points (very good)
○: 5 points or less exceeding 3.5 points (good)
Δ: 3 points or less exceeding 1.5 points (slightly poor)
×: 1.5 points or less (defect)

Evaluation was performed by the following method.
(Evaluation methods)
About this invention products 1-3 and comparative products 1-2, a use panel is tested by a professional panel by 20 people, and the "stickiness" when the sample is applied to the skin is evaluated according to the following criteria, and the average score Judged.
(Evaluation item)
a. No stickiness (absolute evaluation criteria)
(Score): (Evaluation)
6: There is no stickiness at all 5: There is no stickiness at all 4: There is no stickiness at all 3: Normal 2: There is a feeling slightly sticky 1: There is a feeling of stickiness 0: There is a feeling of stickiness (judgment criteria)
(Judgment): (Average score)
: Over 5 points (very good)
○: 5 points or less exceeding 3.5 points (good)
Δ: 3 points or less exceeding 1.5 points (slightly poor)
×: 1.5 points or less (defect)

(Evaluation methods)
The inventive products 1 to 3 and the comparative products 1 to 2 are subjected to a use test by a professional panel by 20 people, and evaluated according to the following criteria with respect to the “uniform stretch feeling” when the sample is applied to the skin. Judged by the average score.
(Evaluation item)
c. Moisturizing feeling over time (absolute evaluation criteria)
(Score): (Evaluation)
6: Elongates very uniformly 5: Elongates evenly 4: Elongates slightly uniformly 3: Normal 2: Does not elongate slightly uniformly 1: Does not elongate uniformly 0: Does not elongate uniformly (Judgment criteria) )
(Judgment): (Average score)
: Over 5 points (very good)
○: 5 points or less exceeding 3.5 points (good)
Δ: 3 points or less exceeding 1.5 points (slightly poor)
×: 1.5 points or less (defect)

(result)
The lotion using the polymers prepared in Example 1 and Example 6 was excellent in skin-familiarity, moist feeling, non-stickiness, and uniform elongation, whereas the polymer in the comparative example was , Both were inferior.

(Prescription)
[Lotion]
Components 1 to 7 shown below were mixed and dissolved at a normal temperature with stirring at respective ratios to prepare a lotion.
(Ingredient) (mass%)
1. Ethanol 10.0
2. Polyoxyethylene hydrogenated castor oil (60 EO) 0.1
3. Perfume appropriate amount 4. Poly (N-ethylacrylamide-acrylic acid) (Example 1) 0.5
5). 1,3-butylene glycol 15.0
6). Preservative 0.1
7). Purified water remaining amount The skin lotion prepared according to the above formulation had a fresh feeling of use without stickiness and was excellent in moisturizing feeling.

[Moisturizing serum-1]
Components 1 to 6 and components 7 to 15 shown below are stirred and mixed at respective ratios and heated to 80 ° C. The latter is added dropwise to the former and stirred to emulsify. Subsequently, it was cooled to prepare a moisturizing serum.
(Ingredient) (mass%)
1. Sucrose fatty acid ester 0.6
2. Glyceryl monostearate 0.1
3. Polyethylene glycol monostearate 0.1
4). Batyl alcohol 0.1
5). Liquid paraffin 4.5
6). Glyceryl trioctanoate 1.5
7). Poly (N-ethylacrylamide-acrylic acid) (Example 2) 1.0
8). 1,3-butylene glycol 6.0
9. Glycerin 2.0
10. Ethanol 13.0
11. Carboxyvinyl polymer 0.1
12 Sodium hydroxide 0.01
13. Preservative 0.1
14 Perfume appropriate amount 15. Purified water remaining amount The moisturizing serum prepared according to the above formulation had a fresh feeling of use without stickiness and was excellent in moisturizing feeling.

[Emulsion]
The components 1-4 shown below and the components 5-12 are stirred and mixed in each ratio, and it heats at 80 degreeC. The latter is added dropwise to the former and stirred to emulsify. Subsequently, it was cooled to prepare an emulsion.
(Ingredient) (mass%)
1. Squalane 5.0
2. Cetanol 1.0
3. Polyethylene ethylene sorbitan monooleate (20E.O.) 2.0
4). Sorbitan sesquioleate 0.8
5). Glycerin 5.0
6). 1,3-butylene glycol 10.0
7). Poly (N, N-diethylacrylamide-acrylic acid) (Example 5) 1.0
8). Carboxyvinyl polymer 0.2
9. Potassium hydroxide 0.1
10. Preservative 0.1
11. Perfume appropriate amount 12. Purified water remaining amount The emulsion prepared according to the above formulation had a fresh feeling of use without stickiness, and was excellent in moisturizing feeling.

[Cream pack]
The components 1-4 shown below and the components 5-12 are stirred and mixed in each ratio, and it heats at 80 degreeC. The latter is added dropwise to the former and stirred to emulsify. Subsequently, the mixture was cooled to prepare a cream pack.
(Ingredient) (mass%)
1. Polyoxyethylene polyoxypropylene cetyl ether (20EO, 4PO)
0.8
2. Diglyceryl monostearate 0.2
3. Glyceryl tri-2-ethylhexanoate 1.0
4). Medu home oil 1.0
5). Glycerin 5.0
6). 1,3-butylene glycol 3.0
7). Poly (N-ethylacrylamide-acrylic acid) (Example 1) 1.0
8). Sodium hydroxide 0.28
9. Hydroxyethyl cellulose 0.3
10. Ascorbic acid 2-glucoside 2.0
11. Preservative 0.1
12 Purified Water Remaining The cream pack prepared by the above formulation had a fresh feeling without stickiness and was excellent in moisturizing feeling after use.

[Impregnation mask]
Components 1 to 9 shown below were stirred and mixed at respective ratios to obtain an aqueous composition. An impregnation mask was prepared by impregnating this aqueous composition into a nonwoven fabric (substantially facial shape having holes and cuts in the eyes, nose and mouth) about 10 times the mass of the nonwoven fabric.
(Ingredient) (mass%)
1. Polyoxyethylene (60E.O.) hydrogenated castor oil 0.1
2. Preservative 0.1
3. Alcohol 5.0
4). Dipropylene glycol 7.0
5). Glycerin 3.0
6). Poly (N-ethylacrylamide-acrylic acid) (Example 1) 0.5
7). Phosphorus monohydrogen phosphate 0.1
8). Monosodium dihydrogen phosphate 0.1
9. Purified water balance The impregnated mask prepared according to the above formulation had a fresh feeling without stickiness, and was excellent in moisturizing feeling after removing the mask.

[Funny]
97 parts of talc is mixed with 3 parts of N-ethylacrylamide homopolymer and ethanol at room temperature, and then heated to 80 ° C. to recover ethanol under reduced pressure. After cooling, the mixture was pulverized with a hammer mill to obtain N-ethylacrylamide homopolymer 3 wt% treated talc.
Ingredients 1 to 9 shown below were stirred and mixed in their respective proportions, and pulverized with a hammer mill to prepare an interesting one.
(Ingredient) (mass%)
1. Poly (N-ethylacrylamide-N-vinylpyrrolidone) (Example 9) 3 wt% treated talc 70.0
2. 2. Remaining silicon-treated sericite Perfluoroalkyl polyether-treated mica titanium 5.0
4). Magnesium stearate 2.0
5). Gunjo 0.2
6). Bengala 0.1
7). Preservative 0.1
8). Silicic anhydride 5.0
9. Perfume Appropriate amount Oshiroi prepared by the above formulation was excellent in moisturizing feeling during use.

[Powder Foundation]
Components 1 to 11 and components 12 to 16 shown below are mixed in respective proportions. The latter was dropped and mixed with the former, pulverized with a hammer mill, pressed into a mold and molded to prepare a powder foundation.
(Ingredient) (mass%)
1. Titanium oxide 10.0
2. Zinc oxide 5.0
3. Mica 20.0
4). 4. Sericite balance Talc 20.0
6). Silicic anhydride 2.0
7). Bengala 0.5
8). Yellow iron oxide 2.0
9. Black iron oxide 0.3
10. Mica titanium 5.0
11. Polystyrene 3.0
12 Preservative 0.1
13. Poly (N-ethylacrylamide-2- (glucosyloxy) ethyl methacrylate) (Example 8) 1.0
14 Glyceryl trioctanoate 1.0
15. Dimethylpolysiloxane 1.0
16. 2-Ethylhexyl paramethoxycinnamate 3.0
The powder foundation prepared by the above formulation was excellent in moisturizing feeling during use.

[Liquid Foundation]
Components 1 to 8 and Components 9 to 13 shown below are stirred and mixed at respective ratios and heated to 80 ° C. Add the latter to the former and mix. Subsequently, the mixture was cooled to prepare a liquid foundation.
(Ingredient) (mass%)
1. Squalane 10.0
2. Decamethylcyclopentasiloxane 20.0
3. Polyoxyethylene-modified dimethylpolysiloxane 5.0
4). Talc 5.0
5). Bengala 0.5
6). Yellow iron oxide 1.0
7). Black iron oxide 0.1
8). Titanium oxide 10.0
9. Propylene glycol 10.0
10. Poly (N-ethylacrylamide-acrylic acid) (Example 1) 1.0
11. Preservative 0.1
12 Perfume appropriate amount13. Purified water balance The liquid foundation prepared by the above formulation was excellent in moisturizing feeling during use.

[lipstick]
Components 1 to 16 shown below are added in respective proportions and dispersed by roller treatment. The lipstick was prepared by pouring into a mold at a high temperature, filling the container with the molded product after cooling.
(Ingredient) (mass%)
1. Carnauba wax 10.0
2. Heavy liquid isoparaffin 20.0
3. α-olefin oligomer 20.0
4). Liquid paraffin 25.0
5). 5. Diglyceryl triisostearate remaining amount Cetyl isooctanoate 5.0
7). Ozoquelite wax 1.0
8). Hydrogenated rosin acid pentaerythritol 1.0
9. (Ethylene / Propylene) Copolymer 0.1
10. Poly (N-ethylacrylamide-2- (glucosyloxy) ethyl methacrylate) (Example 8) 0.5
11. Red No. 202 0.3
12 Yellow No. 4 aluminum rake 0.7
13. Titanium oxide 0.5
14 Iron oxide coated mica titanium 3.0
15. Dibutylhydroxytoluene 0.01
16. Preservative 0.1
The lipstick prepared by the above formulation was excellent in moisturizing feeling during use.

[Cleansing sheet]
Components 1 to 3 and components 4 to 8 shown below are stirred and mixed at respective ratios and heated to 80 ° C. The latter was dropped and stirred into the former to emulsify, and then components 9 to 11 were added and stirred and mixed to obtain an emulsion composition. A cleansing sheet was prepared by impregnating the emulsion composition into a nonwoven fabric about 10 times the mass of the nonwoven fabric.
(Ingredient) (mass%)
1. Hydrogenated soybean phospholipid 1.0
2. Phytosterol 0.1
3. Glycerin 5.0
4). Dipropylene glycol 5.0
5). Poly (N-ethylacrylamide-acrylic acid) (Example 1) 0.5
6). Neopentyl glycol dicaprate 2.0
7). Liquid paraffin 5.0
8). Light liquid paraffin 0.5
9. Preservative 0.1
10. Ethanol 10.0
11. Purified water remaining amount The cleansing sheet prepared by the above formulation had a fresh, non-sticky feeling of use and was excellent in a moisturizing feeling after use.

[Moisturizing serum-2]
A moisturizing serum was prepared according to the following formulation for the components shown in Table 3.
(Invention products 4-7, comparative products 3-6)
A: Components 1 to 4 are uniformly dissolved at 80 ° C.
B: Components 5 to 11 are uniformly dissolved at 80 ° C.
C: B is dropped and mixed in A and emulsified.

(Invention product 8, comparative product 7) <Liposome-containing composition>
A: Components 1 to 4 are uniformly dissolved at 80 ° C.
B: Components 5 to 11 are uniformly dissolved at 80 ° C.
C: B is dropped and mixed in A, and finely emulsified with a disperse mill.

  As shown in Table 3, the liposome composition obtained by miniaturization had little stickiness at the time of application and was excellent in moisturizing feeling over time.

Evaluation was performed by the following method.
(Evaluation methods)
About the present invention products 4-8 and comparative products 3-7, a use test is conducted by a professional panel by 20 people, and the “stickiness” when the sample is applied to the skin is evaluated according to the following criteria, and the average score is obtained. Judged.
(Evaluation item)
a. No stickiness (absolute evaluation criteria)
(Score): (Evaluation)
6: There is no stickiness at all 5: There is no stickiness at all 4: There is no stickiness at all 3: Normal 2: There is a feeling slightly sticky 1: There is a feeling of stickiness 0: There is a feeling of stickiness (judgment criteria)
(Judgment): (Average score)
: Over 5 points (very good)
○: 5 points or less exceeding 3.5 points (good)
Δ: 3 points or less exceeding 1.5 points (slightly poor)
×: 1.5 points or less (defect)

(Evaluation methods)
About the present invention products 4-8 and comparative products 3-7, a use test is conducted by a professional panel by 20 people, and the “moist feeling” when the sample is applied to the skin is evaluated according to the following criteria, and the average score is obtained. Judged.
(Evaluation item)
b. Moist feeling (absolute evaluation criteria)
(Score): (Evaluation)
6: Feels moist 5: Moist )
(Judgment): (Average score)
: Over 5 points (very good)
○: 5 points or less exceeding 3.5 points (good)
Δ: 3 points or less exceeding 1.5 points (slightly poor)
×: 1.5 points or less (defect)

(Evaluation methods)
For the inventive products 4 to 8 and comparative products 3 to 7, a use test is conducted by a professional panel by 20 people, the sample is applied to the skin, and the “humidity feeling over time” after 6 hours is evaluated according to the following criteria. The average score was determined.
(Evaluation item)
c. Moisturizing feeling over time (absolute evaluation criteria)
(Score): (Evaluation)
6: Feels very moisturized 5: Feels moisturized 4: Feels slightly moisturized 3: Normal: Does not feel moisturized slightly 1: Does not feel moisturized 0: Does not feel moisturized at all (judgment criteria) )
(Judgment): (Average score)
: Over 5 points (very good)
○: 5 points or less exceeding 3.5 points (good)
Δ: 3 points or less exceeding 1.5 points (slightly poor)
×: 1.5 points or less (defect)

[Moisturizing serum-3]
A moisturizing serum was prepared according to the following formulation for the components shown in Table 4.
(Invention product 9, comparative product 8, 9) <Liposome-containing composition>
A: Components 1 to 4 are uniformly dissolved at 80 ° C.
B: Components 5 to 6 are uniformly dissolved at 80 ° C.
C: B is dropped and mixed in A, and finely emulsified with a disperse mill.
D: Components 7 to 9 are uniformly dissolved at room temperature and added to C and mixed.

(Invention product 10, comparative product 10)
A; Components 7 to 9 are uniformly dissolved at room temperature.

(Evaluation methods)
About this invention products 9 and 10 and comparative products 8-10, the skin moisture content by continuous use (used twice a day in the morning and evening) was measured. After washing the inside of the forearm of the panel with facial soap and acclimating for 20 minutes in an environment with a constant humidity and temperature, reflection measurement is performed with a near-infrared spectrometer (Spectrum 400 PerkinElmer). The amount of water was detected at the peak height. The skin moisture content before use (0 day) was plotted as 100%, and the skin moisture content after use was plotted. The results are shown in FIG.

[result]
The water retention when the sample of the water-soluble polymer of the present invention was applied to the skin showed the same water retention as theanine, which is a material for which the water retention effect is focused. In addition, the water-soluble polymer of the present invention can be synergistically imparted with moisture retention by being blended with the liposome-containing cosmetic.

Claims (10)

One or more repeating units represented by formula (1) derived from an acrylamide or methacrylamide polymerizable monomer: (A)

(In the formula, R1 represents a hydrogen atom or a methyl group, R2 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R3 represents an alkyl group having 1 to 3 carbon atoms or a hydroxy group having 1 to 3 carbon atoms. Represents an alkyl group),
One or more repeating units derived from a polymerizable monomer that gives a water-soluble homopolymer: (B)
And containing
The molar ratio of A: B is 99.98: 0.02-10: 90;
Water-soluble (meth) acrylamide type for cosmetics or topical skin preparations, characterized in that the mass reduction rate after standing for 6 hours of a 50% by mass aqueous solution of the polymer at 30 ° C. and 60% relative humidity is less than 25% by mass Copolymer. The cosmetic according to claim 1, wherein the mass reduction rate of the 50% by mass aqueous solution of the polymer when the relative humidity is lowered from 60% to 40% at a temperature of 30 ° C is less than 3% by mass. Water-soluble (meth) acrylamide copolymer for external use on skin. The makeup according to claim 1 or 2, wherein the mass increase rate of a 50% by mass aqueous solution of the polymer is less than 3% by mass when the relative humidity is increased from 40% to 60% at a temperature of 30 ° C. Water-soluble (meth) acrylamide copolymer for use in skin preparations or skin preparations The one or more kinds of repeating units derived from a polymerizable monomer that gives a water-soluble homopolymer: (B) is a repeating unit represented by the following formula (2): The water-soluble (meth) acrylamide copolymer for cosmetics or skin external preparation in any one of 1-3.

[Wherein, R4 is a hydrogen atom or a methyl group, and Y is the following general formula (3) to (6)

(In the formula, R5 is a hydrogen atom, an alkali metal element, an ammonium group, a monovalent group derived from an organic base, a — ((CH ₂ ) pO) qH group (where p is 2 or 3, p When q is 2, q represents any integer of 1 to 10, and when p is 3, q represents any integer of 1 to 3), or-(CH ₂ CH (OH) CH ₂ O ) RH group (wherein r represents any integer of 1 to 10)),

,

Or

Represents. However, when Y is represented by Formula (4) or Formula (5), R4 is a hydrogen atom. ] One or more repeating units represented by formula (1) derived from an acrylamide or methacrylamide polymerizable monomer: (A)

(In the formula, R1 represents a hydrogen atom or a methyl group, R2 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R3 represents an alkyl group having 1 to 3 carbon atoms or a hydroxy group having 1 to 3 carbon atoms. Represents an alkyl group),
Following formula (2)

[Wherein R4 is a hydrogen atom or a methyl group, and Y is the following general formula (3 ′), (5) or (6)

(In the formula, R5 ′ represents a — ((CH ₂ ) pO) qH group (where p is 2 or 3, and when p is 2, q represents an integer of 1 to 10; In the case of 3, q represents any integer of 1 to 3),-(CH ₂ CH (OH) CH ₂ O) rH group (where r represents any integer of 1 to 10). ),

Or

Represents. However, when Y is represented by Formula (5), R4 is a hydrogen atom. ]
A repeating unit represented by: (B),
The molar ratio of A: B is 99.98: 0.02 to 10:90.
A water-soluble (meth) acrylamide copolymer characterized by (A) A liposome-containing water-soluble (meth) acrylamide copolymer composition comprising the water-soluble (meth) acrylamide copolymer according to any one of claims 1 to 5 and (B) a phospholipid. . The liposome-containing water-soluble (meth) acrylamide copolymer composition according to claim 6, further comprising (C) at least one selected from the group consisting of cholesterol, cholesterol derivatives, phytosterols and phytosterol derivatives. The liposome-containing water-soluble (meth) acrylamide copolymer composition according to claim 6 or 7, further comprising (D) at least one selected from the group consisting of glycerin and 1,3-butylene glycol. Cosmetics or skin external preparation containing the water-soluble (meth) acrylamide type copolymer in any one of Claims 1-5. A cosmetic or external skin preparation comprising the liposome-containing water-soluble (meth) acrylamide copolymer composition according to any one of claims 6 to 8.

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