JP2017145208A - Aerosol-type cosmetics for scalp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aerosol-type skin treatment agent, which is prevented from dripping without using any water-soluble thickener, applied by hand without slimness, and gives a sense of smoothness to the scalp.SOLUTION: According to the present invention, there is provided an aerosol-type skin treatment agent comprising a stock solution containing components (A) and (B) and a component (C) a carbonic acid gas: (A) an organopolysiloxane graft polymer; and (B) water. Here, the organopolysiloxane graft polymer comprises an organopolysiloxane segment (a) as a main chain and a polymer segment (b) derived from an unsaturated monomer as a side chain. The polymer segment (b) derived from the unsaturated monomer contains 50% by mass or more and 100% by mass or less of a N, N-dimethylacrylamide-derived repetitive unit. The mass ratio (a/b) of the organopolysiloxane segment (a) and the polymer segment (b) derived from the unsaturated monomer in the organopolysiloxane graft polymer is from 10/90 to 70/30.SELECTED DRAWING: None

Description

  The present invention relates to an aerosol type skin treatment agent.

  Carbon dioxide gas is known to have a blood circulation promoting effect, and aerosol-type scalp cosmetics using carbon dioxide as a propellant are widely used. However, such aerosol-type scalp cosmetics have a problem that dripping easily occurs. In order to solve this problem, various compositions in which the viscosity of the stock solution is adjusted by adding a water-soluble thickener have been proposed. For example, Patent Document 1 discloses an aerosol composition comprising a stock solution containing hydrophobized hydroxypropylmethylcellulose and water and a propellant made of carbon dioxide.

  On the other hand, since organopolysiloxane has many excellent features, various forms of organopolysiloxane or cosmetics containing them have been proposed. For example, in Patent Document 1, a cosmetic containing an organopolysiloxane graft polymer having a repeating unit derived from N, N-dimethylacrylamide at a specific ratio as a side chain is less sticky during and after hair setting. It has been disclosed that it has setability and set durability.

JP 2013-170152 A International Publication No. 2014/002707 Pamphlet

  However, a composition containing a water-soluble thickener such as the aerosol composition described in Patent Document 1 cannot be easily applied to the skin because the discharged product is in the form of foam and the viscosity of the stock solution is high. In addition, there was a problem that it was slippery when applied by hand after application.

  On the other hand, the organopolysiloxane graft polymer described in Patent Document 2 can also be used for aerosol-type cosmetics, but there is no description to suppress dripping when applied to the skin, and the effect is also sufficient. But there was room for improvement.

  Therefore, the present invention relates to an aerosol-type skin treatment agent that suppresses dripping without using a water-soluble thickener, does not become slippery when applied by hand after application to the skin, and gives a smooth feeling to the skin after application. .

  In the aerosol-type skin treatment agent using carbon dioxide gas as a propellant, the present inventors have incorporated an organopolysiloxane graft polymer having a repeating unit derived from a specific N, N-dimethylacrylamide in a stock solution to thereby dissolve water. It has been found that the sustainability of fine bubbles generated by the vaporization of carbon dioxide in the discharge liquid is improved without using a functional thickener, that is, without changing the viscosity of the stock solution. As a result, dripping when applied to the skin is suppressed, and since no water-soluble thickener is used, there is no stickiness when applied by hand. I found that I could get a feeling.

The present invention provides an aerosol type skin treatment agent comprising a stock solution containing the following components (A) and (B) and component (C) carbon dioxide.
(A) An organopolysiloxane graft polymer having an organopolysiloxane segment (a) as a main chain and a polymer segment (b) derived from an unsaturated monomer as a side chain, the unsaturated monomer The polymer segment (b) derived from the body contains 50% by mass or more and 100% by mass or less of repeating units derived from N, N-dimethylacrylamide, and the polymer segment (a) in the organopolysiloxane graft polymer Organopolysiloxane graft polymer in which the mass ratio (a / b) of the polymer segment (b) derived from a saturated monomer is from 10/90 to 70/30
(B) Water

  The aerosol type skin treatment agent of the present invention can prevent dripping at the time of application to the skin by maintaining very fine bubbles generated in the discharge, and is applied when the skin is familiarized with the hand. Without applying, it can give a smooth feeling to the skin after application. As used herein, the term “foam” refers to a “foam” that forms a firm, bulky foam that is discharged with an aerosol foam-type hair conditioner, an aerosol foam-type hair dye, or the like. "Is a fine" bubble "generated by the evaporation of carbon dioxide in a low-viscosity discharge liquid.

[Component (A): Organopolysiloxane graft polymer having repeating units derived from N, N-dimethylacrylamide]
As the component (A), an organopolysiloxane graft polymer represented by the following general formula (1) is preferable.

[Where,
R ¹ may be the same or different and represents an alkyl group having 1 to 8 carbon atoms,
R ² may be the same or different and represents a hydroxyl group or a hydrocarbon group having 1 to 22 carbon atoms;
R ³ represents an alkylene group which may contain a hetero atom,
R ⁴ represents a hydrogen atom or a methyl group,
R ⁵ may be the same or different and represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms which may be substituted by a hydroxyl group, an amino group or a mono- or di-C _1-4 alkylamino group,
p represents a number from 50 to 2,000, q represents a number from 3 to 50, and m represents a number from 10 to 100.
However, in the m repeating units, the ratio of the repeating units in which two R ^{5 s} are both methyl groups is 50% by mass or more and 100% by mass or less. ]

  Component (A) has a polymer segment (b) derived from an unsaturated monomer that is derived from N, N-dimethylacrylamide in an amount of 50% by mass or more in the side chain of the organopolysiloxane segment (a) as the main chain. And an organopolysiloxane graft polymer in which the mass ratio (a / b) of the organopolysiloxane segment (a) and the polymer segment (b) derived from the unsaturated monomer is 10/90 or more and 70/30 or less. When the organopolysiloxane graft polymer represented by the general formula (1) is used as the component (A), the polymer segment (b) derived from the unsaturated monomer is m in the general formula (1). The organopolysiloxane segment (a) refers to the whole excluding the polymer segment (b) derived from the unsaturated monomer in the general formula (1).

In the general formula (1), R ¹ is an alkyl group having 1 to 8 carbon atoms, and examples of the alkyl group include a linear, branched, or cyclic alkyl group. From the viewpoint of water dispersibility of the organopolysiloxane graft polymer of component (A), a linear or branched alkyl group having 1 to 6 carbon atoms is preferred, and a linear or branched alkyl group having 1 to 4 carbon atoms. Is more preferable, a linear or branched alkyl group having 1 to 3 carbon atoms is more preferable, and a methyl group is still more preferable.

R ² is a hydroxyl group or a hydrocarbon group having 1 to 22 carbon atoms. The hydrocarbon group having 1 to 22 carbon atoms may be saturated or unsaturated, and may be linear or branched. Or a branched alkyl group is preferred. R ² is more preferably a hydroxyl group or a hydrocarbon group having 1 to 8 carbon atoms. Examples of the hydrocarbon group having 1 to 8 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, tert- Examples thereof include a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. Among them, a hydroxyl group or a methyl group is preferable, and a methyl group is more preferable from the viewpoint of availability of raw materials when producing the organopolysiloxane graft polymer of component (A).

R ³ is an alkylene group which may contain a hetero atom, and the number of carbon atoms thereof is preferably 2 or more, more preferably from the viewpoint of availability of raw materials when producing the organopolysiloxane graft polymer of component (A). Is preferably 3 or less, and preferably 20 or less, more preferably 10 or less, and still more preferably 8 or less, from the viewpoint of water dispersibility of the organopolysiloxane graft polymer of component (A).

In the present invention, the alkylene group which may contain a hetero atom is one or more atoms or functional groups selected from an oxygen atom, a sulfur atom, —NH—, —COO—, —NHCO—, and —NR ³¹ CO—. It may be divided by a group. That is, the alkylene group which may contain a hetero atom may have a structure of “— (alkylene group moiety 1) — (the above atom or functional group) — (alkylene group moiety 2) —”. The carbon number of the alkylene group means the sum of the carbon number of the alkylene group part 1 and the carbon number of the alkylene group part 2, that is, the sum of the carbon number of the part other than the above atoms or functional groups that divide the alkylene group. Say. Here, R ³¹ is an alkyl group having 1 to 3 carbon atoms. When the alkylene group which may contain a hetero atom is interrupted by the above atom or functional group, it is interrupted by -NHCO- from the viewpoint of easy production of the organopolysiloxane graft polymer of component (A). Preferably it is.

  In the present invention, the alkylene group which may contain a hetero atom includes a hydroxyl group, an amino group, an alkyl (C1 or more and 3 or less) amino group, a dialkyl (C1 or more and 3 or less) amino group, an amino group and a carbon number. One or more monovalent groups selected from amide groups, carboxy groups, and alkyl (1 to 3 carbon atoms) ester groups obtained by dehydration condensation of 2 or more and 4 or less fatty acids may be substituted. In this case, the carbon number of the alkylene group which may contain a hetero atom does not include the carbon number of these substituents. From the viewpoint of easy availability of raw materials during the production of the component (A) organopolysiloxane graft polymer, the alkylene group which may contain a hetero atom is an acetamido group, an alkyl (C1 or more and 3 or less) amino group, And one or more monovalent groups selected from amino groups are preferably substituted.

In the present invention, the alkylene group that may contain a heteroatom is a divalent heteroatom selected from —O—, —S—, —NH—, —NR ³² —, and —COO—, or a heteroatom. A divalent group containing may be substituted. Here, R ³² is an alkyl group (having 1 to 3 carbon atoms) which may be substituted by a dimethylamino group. In the case where the heteroatom or a divalent group containing a heteroatom serves as a linking group with a polymer segment derived from an unsaturated monomer, the alkylene group that may contain a heteroatom is an unsaturated monomer. It is bound to the polymer segment derived from the body. In other cases, it is bonded to a hydrogen atom. From the viewpoint of easy production of the organopolysiloxane graft polymer of component (A), the alkylene group which may contain a hetero atom is preferably substituted with -S-.

The alkylene group (R ³ ) which may contain a hetero atom is a polymer segment derived from an unsaturated monomer via the hetero atom, preferably a nitrogen atom, an oxygen atom, or a sulfur atom, more preferably a sulfur atom. It is preferable that it couple | bonds with.
Therefore, the “alkylene group optionally containing a heteroatom” represented by R ³ includes
(A) an unsubstituted alkylene group,
(B) an oxygen atom, a sulfur atom, -NH -, - COO -, - NHCO-, and one or more atoms or functional shed alkylene group by a group selected from -NR ³¹ CO-,
(C) A hydroxyl group, an amino group, an alkyl (C1 or more and 3 or less) amino group, a dialkyl (C1 or more and 3 or less) amino group, an amino group and a fatty acid having 2 or more and 4 or less carbon atoms are obtained by dehydration condensation. An alkylene group substituted with one or more monovalent groups selected from an amide group, a carboxy group, and an alkyl (C 1 or more and 3 or less) ester group;
(D) In addition to an alkylene group substituted with a divalent heteroatom selected from —O—, —S—, —NH—, —NR ³² — and —COO—, or a divalent group containing a heteroatom, An alkylene group consisting of a combination of two or more of (i), (c) and (d) is applicable.

Specific examples of the alkylene group that may contain a hetero atom of R ³ include the following formulas (i) to (xii). Of these, the following formulas (xi) and (xii) are preferred from the viewpoint of ease of production of the organopolysiloxane graft polymer of component (A).

In formulas (i) to (xii), * represents a site bonded to a silicon atom in the general formula (1), and ** represents a site bonded to a polymer segment derived from an unsaturated monomer.
In the formula (xii), X ³¹ is at least one selected from —O—, —OCO—, —COO—, —CONH—, and —NHCO—, and is used for producing the organopolysiloxane graft polymer of component (A). From the viewpoint of ease, —CONH— or —NHCO— is preferable, and —NHCO— is more preferable.

In the formula (xii), R ³³ is a hydroxyl group, an amino group, an alkyl (C 1 or more and 3 or less) amino group, a dialkyl (C 1 or more and 3 or less) amino group, an amino group and 2 or more and 4 or less carbon atoms. Is an alkylene group which may be substituted with one or more monovalent groups selected from an amide group, a carboxy group, and an alkyl (having 1 to 3 carbon atoms) ester group obtained by dehydration condensation. The substituent is preferably an acetamido group, an alkyl (having 1 to 3 carbon atoms) amino group, and an amino group from the viewpoint of availability of raw materials during production. The number of carbon atoms of the alkylene group represented by R ³³ is preferably 2 or more, more preferably 3 or more, from the viewpoint of ease of production of the organopolysiloxane graft polymer of component (A). From the viewpoint of the water dispersibility of the organopolysiloxane graft polymer of A), it is preferably 10 or less, more preferably 6 or less.
Specific examples of R ³³ include the following formulas (xiii) to (xv).

In the formula (xiv), X ⁻ represents an anion such as a halide ion such as a chloride ion or a bromide ion, an acetate ion, or an alkyl (having 1 to 3 carbon atoms) sulfate ion.

R ⁴ represents a hydrogen atom or a methyl group, and among them, a hydrogen atom is preferable.

R ⁵ may be the same or different and represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms which may be substituted by a hydroxyl group, an amino group, or a mono- or di-C _1-4 alkylamino group. The hydrocarbon group having 1 to 8 carbon atoms in R ⁵ may be saturated or unsaturated, and may be linear or branched, but is preferably a linear or branched alkyl group. R ⁵ is preferably a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, a tert-butyl group, a hydroxymethyl group, a hydroxyethyl group, or a dimethylaminopropyl group from the viewpoint of availability of raw materials during production. Among these, a hydrogen atom, a methyl group, and a tert-butyl group are more preferable.

R ^{1 to} R ⁵ are each a group in which R ¹ and R ² are a methyl group, R ³ is a formula (xii), R ⁴ is a hydrogen atom, and R ⁵ may be the same or different. More preferred are polymers which are selected from groups and tert-butyl groups. Further preferred is a polymer having the INCI name of Polysilicone-28.

However, in the m repeating units in the general formula (1), the ratio of the repeating units in which two R ⁵ are both methyl groups is 50% by mass or more from the viewpoint of good water dispersibility of the component (A). The amount is preferably 70% by mass or more, more preferably 75% by mass or more, and it is 100% by mass from the viewpoint of imparting a smooth feeling to the skin after application without applying it when applied to the skin by hand. % Or less, preferably 95% by mass or less, more preferably 90% by mass or less.

  p is 50 or more, preferably 80 or more, more preferably 100 or more, and 2,000 from the viewpoint of imparting a smooth feeling to the skin after application, without being slicked when applied by hand after application to the skin. Hereinafter, it is preferably 1,300 or less, more preferably 700 or less. q is 3 or more, preferably 5 or more, and 50 or less, preferably 30 or less, from the viewpoint of water dispersibility of the organopolysiloxane graft polymer of component (A). m is 10 or more, preferably 15 or more, more preferably 20 or more, and 100 or less, preferably 70 or less, from the viewpoint of good water dispersibility of the organopolysiloxane graft polymer of component (A). Preferably it is 50 or less.

  From the viewpoint of improving the persistence of the foam of component (A) and suppressing dripping, as well as being smooth when applied by hand after application to the skin and imparting a smooth feeling to the skin after application. The mass ratio (a / b) between the polysiloxane segment (a) and the polymer segment (b) derived from the unsaturated monomer is 10/90 or more, preferably 20/80 or more, more preferably 30 / 70 or more, more preferably 35/65 or more, and 70/30 or less, preferably 60/40 or less.

  In the present specification, the mass ratio (a / b) is “injected at the time of production” when the organopolysiloxane graft polymer of the component (A) is produced from the radical reactive organopolysiloxane described later. From the “total mass (c) of radical-reactive organopolysiloxane” and “total mass (d) of unsaturated monomer added during production”, “unsaturated monomer not bonded to organopolysiloxane produced during production” The ratio (c / (de)) with the value obtained by subtracting the total mass (e) of the polymer derived from the monomer is considered to be the same (the following formula (I)).

    a / b = c / (d−e) (I)

  In addition, in the organopolysiloxane graft polymer molecule of component (A), the number average molecular weight (MNg) of the organopolysiloxane segment between the polymer segments derived from adjacent unsaturated monomers (hereinafter referred to as “graft point molecular weight”). From the viewpoint of improving the persistence of the foam and suppressing dripping, and does not become slippery when applied by hand after application to the skin, and gives a smooth feeling to the skin after application. 500 or more, more preferably 700 or more, still more preferably 1,000 or more, still more preferably 1,500 or more, and preferably 10,000 or less, more preferably from the viewpoint of water dispersibility of the organopolysiloxane graft polymer of component (A). It is 5,000 or less, more preferably 3,000 or less, and further preferably 2,500 or less.

Here, “an organopolysiloxane segment between polymer segments derived from adjacent unsaturated monomers” means a bond of an unsaturated monomer-derived polymer segment to an organopolysiloxane segment as shown in the following formula. A portion surrounded by a broken line between two points from a point (bonding point A) to a bonding point (bonding point B) of a polymer segment derived from an unsaturated monomer adjacent thereto, and one R ¹ A segment composed of a SiO unit, one R ³ , and y + 1 R ¹ ₂ SiO units.

In the formula, R ¹ and R ³ have the same meaning as in the general formula (1), —W—R ⁶ represents a polymer segment derived from an unsaturated monomer, and W represents a weight derived from the unsaturated monomer. R ⁶ represents a residue of a polymerization initiator or a hydrogen atom, and y represents a positive number.

  The molecular weight between graft points is an average value of the molecular weight of the portion surrounded by a broken line in the above formula, and is the mass (g / mol) of the organopolysiloxane segment per mole of the polymer segment derived from the unsaturated monomer. Can be solved. The molecular weight between graft points is the case where the organopolysiloxane graft polymer of component (A) is produced from the radical reactive organopolysiloxane described below, and is derived from all radical reactive functional groups and unsaturated monomers. When the polymer is bonded, it is considered to be the same as the reciprocal value of the number of moles of radical reactive functional groups (mol / g) present per unit mass of the radical reactive organopolysiloxane.

  In addition, the weight average molecular weight (MWsi) of the organopolysiloxane segment that constitutes the main chain improves the persistence of the foam and suppresses dripping, and does not become slick when applied by hand after application to the skin. From the viewpoint of imparting a smooth feeling to the subsequent skin, it is preferably 3,000 or more, more preferably 5,000 or more, still more preferably 10,000 or more, and still more preferably 15,000 or more. MWsi is preferably 200,000 or less, more preferably 100,000 or less, still more preferably 60,000 or less, and even more preferably 50,000 or less, from the viewpoint of the water dispersibility of the organopolysiloxane graft polymer of component (A).

  When the organopolysiloxane graft polymer of component (A) is produced from the radical reactive organopolysiloxane described below, the MWsi is a radical because the organopolysiloxane segment has a common skeleton with the radical reactive organopolysiloxane. It is substantially the same as the weight average molecular weight (MWra) of the reactive organopolysiloxane and is regarded as the same in the present invention. In addition, MWra is measured by gel permeation chromatography (GPC) under the measurement conditions described in the Examples, and converted to polystyrene.

The weight average molecular weight (MWt) of the organopolysiloxane graft polymer of component (A) improves the persistence of the foam and suppresses dripping, and does not become slippery when applied by hand after application to the skin. From the viewpoint of imparting a smooth feeling to the skin, preferably 10,000 or more, more preferably 14,000 or more, more preferably 17,000 or more, more preferably 30,000 or more, the water dispersibility of the organopolysiloxane graft polymer of component (A) From this viewpoint, it is preferably 200,000 or less, more preferably 160,000 or less, still more preferably 130,000 or less, and still more preferably 95,000 or less.
In this specification, MWt is measured by GPC under the measurement conditions described in the Examples and converted to polystyrene.

  In addition, when the organopolysiloxane graft polymer of component (A) is produced from a radical-reactive organopolysiloxane, the component obtained by using the following formula (II) from MWra and the reciprocal of the aforementioned mass ratio (a / b) The calculated weight average molecular weight (MWtcalc) of the organopolysiloxane graft polymer of (A) improves the persistence of foam and suppresses dripping, and does not become slippery when applied by hand after application to the skin. From the viewpoint of imparting a smooth feeling to the skin after application, it is preferably 10,000 or more, more preferably 14,000 or more, still more preferably 17,000 or more, more preferably 30,000 or more, and water of the organopolysiloxane graft polymer of component (A) From the viewpoint of dispersibility, it is preferably 200,000 or less, more preferably 160,000 or less, still more preferably 130,000 or less, and still more preferably 95,000 or less.

  MWtcalc = MWra × {1 + mass ratio (b / a)} (II)

(Production of organopolysiloxane graft polymer)
Examples of the method for producing the component (A) organosiloxane graft polymer include the method described in Patent Document 1. Specific examples include a graft-from method in which a radical-reactive organopolysiloxane represented by the following general formula (1a) is radically polymerized with a (meth) acrylamide monomer.

[Wherein R ¹ , R ² , p and q have the same meaning as in the general formula (1), and R ⁷ represents an alkyl group having a radical reactive functional group (hereinafter referred to as “radical reactive group-containing alkyl group”). Say). ]

  Here, the radical reactive functional group means a functional group capable of generating a radical, and examples thereof include an ethylenically unsaturated group, a halogeno group such as a chloro group and a bromo group, and a sulfanyl group (mercapto group). It is done. Among these, a sulfanyl group is preferable from the viewpoint of reactivity with an unsaturated monomer and molecular weight control.

In general formula (1a), the number of carbon atoms of the radical-reactive group-containing alkyl group represented by R ⁷ is preferably 2 or more, more preferably 3 or more, from the viewpoint of easy availability of the radical-reactive organopolysiloxane. In addition, from the viewpoint of water dispersibility of the organopolysiloxane graft polymer of component (A), it is preferably 20 or less, more preferably 10 or less, and still more preferably 8 or less.
In the present invention, the number of carbon atoms of the radical reactive functional group-containing alkyl group does not include the number of carbon atoms of the radical reactive functional group even when the radical reactive functional group has carbon. Also when the containing alkyl group is the above-described monovalent group substituted, the carbon number of the monovalent group is not included.

In the general formula (1a), the radical-reactive group-containing alkyl group represented by R ⁷ includes a hydroxyl group, an amino group, an alkyl (1 to 3 carbon atoms) amino group, a dialkyl (1 to 3 carbon atoms) amino group. One or more monovalent groups selected from an amide group, a carboxy group, and an alkyl (carbon number of 1 to 3) ester group obtained by dehydration condensation of an amino group and a fatty acid of 2 to 4 carbon atoms are substituted. It may be. Of these substituents, an acetamido group, an alkyl (C1 or more and 3 or less) amino group, and an amino group are preferable from the viewpoint of easy availability of raw materials during the production of the radical-reactive organopolysiloxane.

In the general formula (1a), the radical-reactive group-containing alkyl group represented by R ⁷ is one selected from an oxygen atom, a sulfur atom, —NH—, —COO—, —NHCO—, and —NR ⁷¹ CO—. It may be divided by the above atoms or functional groups. Here, R ⁷¹ is an alkyl group having 1 to 3 carbon atoms. When the radical-reactive group-containing alkyl group is interrupted by the above atoms or functional groups, it is preferable that the radical-reactive group-containing alkyl group is interrupted by —NHCO— from the viewpoint of availability of radical-reactive organopolysiloxane or production. .

Specific examples of the radical-reactive group-containing alkyl group in the present invention include groups represented by the following formulas (xvi) to (xix). Among them, production of a radical-reactive organopolysiloxane or easiness of acquisition is preferred. From the viewpoint, the following formulas (xviii) and (xix) are preferable. X ⁷¹ and R ^{72 in} formula (xix) and preferred embodiments thereof are the same as X ³¹ and R ^{32 in} formula (xii) and preferred embodiments thereof, respectively.

The radical reactive organopolysiloxane whose radical reactive group is a sulfanyl group can also be obtained as a commercial product, such as “KF-2001” (manufactured by Shin-Etsu Chemical Co., Ltd.). The radical reactive organopolysiloxane is obtained by reacting an organopolysiloxane having one or more reactive functional groups selected from a hydroxyl group, an amino group, a carboxy group, and an epoxy group with a radical reactivity imparting agent. You can also. As the reactive functional group, a hydroxyl group, an amino group, and an epoxy group are preferable from the viewpoint of availability, and an amino group is preferable from the viewpoint of reactivity and handleability.

  The weight-average molecular weight (MWra) of the radical-reactive organopolysiloxane represented by the general formula (1a) improves the persistence of foam and suppresses dripping, and is applied when applied by hand after application to the skin. From the viewpoint of imparting a smooth feeling to the skin after application, it is preferably 3,000 or more, more preferably 5,000 or more, still more preferably 10,000 or more, more preferably 15,000 or more, and the component (A) has a good quality. From the viewpoint of water dispersibility, it is preferably 200,000 or less, more preferably 100,000 or less, still more preferably 60,000 or less, and still more preferably 50,000 or less.

  The number of moles of radical-reactive groups present per unit mass of the radical-reactive organopolysiloxane represented by the general formula (1a) improves the persistence of foam and suppresses dripping, and after application to the skin. From the viewpoint of imparting a smooth feeling to the skin after application without being moistened by hand, preferably 1/500 mol / g or less, more preferably 1/700 mol / g or less, more preferably 1 / 1,000 mol / From the viewpoint of good water dispersibility of the component (A), it is preferably 1 / 10,000 mol / g or more, more preferably 1 / 5,000 mol / g or more, and still more preferably 1 / 3,000 mol / g. g or more.

  The (meth) acrylamide monomers that undergo radical reaction with the radical-reactive organopolysiloxane represented by the general formula (1a) include acrylamide, methacrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide, N -Isopropylacrylamide, Nt-butylacrylamide, N, N-dimethylaminopropylacrylamide, N-methylolacrylamide, N-hydroxyethylacrylamide and the like. In the present invention, among these (meth) acrylamide monomers, N, N-dimethyl (meth) acrylamide is 50% by mass or more from the viewpoint of good water dispersibility of the component (A), It is preferably 70% by mass or more, more preferably 75% by mass or more, and 100% by mass from the viewpoint of imparting a smooth feeling to the skin after application without applying it when applied to the skin by hand. Or less, preferably 95% by mass or less, more preferably 90% by mass or less.

  The method for polymerizing the unsaturated monomer in the presence of the radical-reactive organopolysiloxane is not particularly limited, and a bulk polymerization method, a solution polymerization method, a suspension polymerization method, etc. can be adopted, but a solution polymerization method is particularly preferable. .

  Examples of the polymerization initiator include azo initiators such as 2,2′-azobisisobutyronitrile and 2,2′-azobis (2,4-dimethylvaleronitrile), and peroxides such as lauroyl peroxide and benzoyl peroxide. Examples thereof include oxide initiators and persulfate initiators such as ammonium persulfate. Further, polymerization may be initiated by generating radicals by light irradiation or the like. As the polymerization initiator, 2,2′-azobis (2,4-dimethylvaleronitrile) is preferable from the viewpoint of reactivity.

  The content of the organopolysiloxane graft polymer of component (A) in the stock solution is preferably 0.005% by mass or more, more preferably 0.01% by mass or more, and still more preferably, from the viewpoint of improving the persistence of foam and suppressing dripping. Is 0.04% by mass or more, more preferably 0.08% by mass or more, and preferably 2.0% by mass from the viewpoint of giving a smooth feeling to the skin after application without applying it when applied to the skin by hand. % Or less, more preferably 1.0% by mass or less, still more preferably 0.5% by mass or less, and still more preferably 0.3% by mass or less.

[Component (B): Water]
The water content of component (B) in the stock solution is the remaining amount excluding component (A) and optional components.

[Component (C): Carbon dioxide]
The content of the carbon dioxide gas of the component (C) in the aerosol-type skin treatment agent of the present invention is preferably 0.1% by mass or more, from the viewpoint of improving the sustainability of foam, improving stability, and preventing dripping. Preferably it is 0.5 mass% or more, More preferably, it is 1.0 mass% or more, Preferably it is 5 mass% or less, More preferably, it is 4 mass% or less, More preferably, it is 3 mass% or less.

  The mass ratio (C) / (A) of the component (C) to the component (A) in the aerosol-type skin treatment agent of the present invention does not become slippery when applied by hand after application to the skin, and the skin after application From the viewpoint of imparting a smooth feeling to the skin, preferably 2.5 or more, more preferably 3.0 or more, more preferably 3.5 or more, and still more preferably 4.0 or more. Also, the viewpoint of improving the persistence of foam and preventing dripping at the time of application Therefore, it is preferably 50 or less, more preferably 40 or less, still more preferably 30 or less, still more preferably 25 or less, still more preferably 20 or less, still more preferably 15 or less, and still more preferably 10 or less.

[Component (D): Ethanol]
The stock solution preferably contains ethanol as a component (D) from the viewpoint that it does not become slippery when hand-applied after application to the skin and gives a smooth feeling to the skin after application. The content of the component (D) ethanol in the stock solution is preferably not less than 0.1% by mass, more preferably from the viewpoint of giving a smooth feeling to the skin after application, without being slippery when applied by hand after application to the skin. Is 5% by mass or more, more preferably 10% by mass or more, more preferably 20% by mass or more, and preferably 70% by mass or less, more preferably from the viewpoint of improving the persistence of foam and suppressing dripping. Is 65% by mass or less, more preferably 60% by mass or less.

  The mass ratio (D) / (A) of component (D) to component (A) in the stock solution does not become slippery when applied by hand after application to the skin, and gives a smooth feeling to the skin after application Therefore, preferably 30 or more, more preferably 50 or more, more preferably 100 or more, more preferably 200 or more, from the viewpoint of improving the persistence of the foam and suppressing dripping, preferably 700 or less, more Preferably it is 500 or less, More preferably, it is 450 or less, More preferably, it is 400 or less.

[Ingredient (E): Hair-growth ingredient]
When the aerosol skin treatment agent of the present invention is used as a scalp cosmetic, the stock solution preferably further contains a hair-growth component as component (E). Examples of the hair growth component include a blood circulation promoter, a hair follicle activator, and an anti-androgen agent.

  Blood circulation promoters include nicotinamide, acetylcholine, assembly extract, carrot extract, ginkgo biloba extract, carpronium chloride, diphenhydramine hydrochloride, γ-oryzanol, cercretin, vitamin E and its derivatives, camphor, chili tincture, ginger tincture, Dutch mustard , Cantalis tincture, salamander extract, peppermint oil, horseradish radish extract, minoxidil and its derivatives, cromakalim, diazoxide and its derivatives, nicorandil, pinacidil, phthalides, quina extract, spruce extract and the like.

  Examples of hair follicle activators include trans-3,4'-dimethyl-3-hydroxyflavanone, N-acetyl-L-methionine, Tamatsuki kurafuji, cephalanthin, kudin extract, adenosine triphosphate disodium, potassium aspartate, photosensitive dye 301, pentadecane glyceride, hinokitiol, chinchetsu carrot, flavanonol and its derivatives, hypericum extract, maikai flower extract, coleus extract, grape extract, biotin, mononitroguaiacol sodium, jaundice extract, yeast extract, garlic component, tiso extract, placenta Extract, button pi extract, royal jelly and the like.

  Anti-androgenic agents include cyproterone acetate, 11-α-hydroxyprogesterone, flutamide, 3-deoxyadenosine, chlormadinone acetate, ethinyl estradiol, spironolactone, epitesterone, glycyrrhizic acid and its derivatives, glycyrrhetinic acid and its derivatives, clove extract , Aloe extract, salamander extract, quacharate extract and the like.

  Component (E) may be used alone or in combination of two or more. The content of the component (E) in the aerosol skin treatment agent of the present invention is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, still more preferably 0.07% by mass or more, and preferably 7% by mass. % Or less, more preferably 5% by mass or less, and still more preferably 3% by mass or less.

(Water-soluble thickener)
The aerosol-type skin treatment agent of the present invention can suppress dripping without using a water-soluble thickener, and therefore, from the viewpoint of non-stickiness when applied by hand, smoothness of the skin after application, etc. It is preferable not to contain a water-soluble thickener. Here, “not containing” includes not substantially containing. Note that “substantially” means that the component (A) or an arbitrary component is not intended to be excluded unless it is inevitably contained. Even when a small amount of a water-soluble thickener is contained in order to further suppress dripping, the content of the water-soluble thickener in the stock solution is preferably 0.05% by mass or less, more preferably 0.01% by mass or less. 0.005 mass% or less is more preferable.

  In addition to the above components, the aerosol type skin treatment agent of the present invention can contain various additive components used in normal cosmetics depending on the purpose. For example, surfactants; bactericides such as triclosan and trichlorocarbanilide; anti-dandruff agents such as zinc pyrithione and octopirox; humectants such as eucalyptus extract and glycerin; preservatives such as methylparaben and butylparaben; ethylenediaminetetraacetic acid or Chelating agents such as salts thereof, hydroxyethanediphosphonic acid or salts thereof; pH adjusting agents such as sodium hydroxide and potassium hydroxide; salts such as sodium chloride; other pearlizing agents, fragrances, dyes, UV absorbers, antioxidants An agent or the like can be contained.

  In order to produce the aerosol type skin treatment agent of the present invention, a component other than the carbon dioxide gas of the component (C) is mixed to prepare a stock solution and put into a pressure vessel for aerosol, and a method of enclosing high-pressure carbon dioxide gas therein, pressure resistance Put a component that generates carbon dioxide gas containing carbonate such as sodium bicarbonate in a container, add a suitable pH adjuster to this to generate carbon dioxide gas, and immediately seal it, dry ice pellets in the container Although a method of putting and sealing can be adopted, a method of enclosing high-pressure carbon dioxide gas is preferable.

A part of carbon dioxide is dissolved and blended in the stock solution, and a part of the carbon dioxide exists as a gas in the container. In the present invention, it is important that the carbon dioxide gas is dissolved and blended in the stock solution from the standpoint of the refreshing feeling and the medicinal efficacy of the blended medicinal ingredients, and the carbon dioxide gas in the inner solution injected into the skin. The concentration is preferably 60 ppm or more. The amount of carbon dioxide can be adjusted by adjusting the amount of carbon dioxide injected (pressed). Generally, the pressure in the container should be 1.2-10 kg / cm ² (gauge pressure) at a temperature of 35 ° C. It is preferable that the pressure be 4.5 to 10 kg / cm ² (gauge pressure).

  The aerosol type skin treatment agent of the present invention can be applied without particular limitation as long as it is human skin. Above all, for the scalp where hair is often grown, the effect of the present invention that it is possible to prevent dripping by improving foam retention without increasing the viscosity of the composition, it can be applied to the scalp. It becomes easier, and when an active ingredient is blended, the effect can be sufficiently exhibited. Therefore, the aerosol skin treatment agent of the present invention is preferably an aerosol skin treatment agent for scalp.

Synthesis Example 1 Synthesis of Polysilicone-28 (organopolysiloxane graft polymer represented by general formula (1) of component (A))
(1) Synthesis of radical-reactive organopolysiloxane Side-chain primary aminopropyl-modified organopolysiloxane as an organopolysiloxane having a reactive functional group in a separable flask equipped with a reflux condenser, thermometer, nitrogen inlet tube, and stirrer 100 g of siloxane (weight average molecular weight 30,000, mole number of amino group per unit mass; 1 / 2,030 mol / g, manufactured by Toray Dow Corning) and 8 g of N-acetyl-DL-homocysteine thiolactone were charged. Under a nitrogen atmosphere, the temperature was raised to 100 ° C. and stirred for 3 hours to synthesize a radical-reactive organopolysiloxane having a sulfanyl group. When the residual amount of amino groups was measured by potentiometric titration, 99% of the amino groups of the side chain primary aminoisopropyl-modified organopolysiloxane used as a raw material reacted with N-acetyl-DL-homocysteine thiolactone (amino (Conversion rate 99%). Therefore, the number of moles of sulfanyl group per unit mass of the radical reactive organopolysiloxane is 1 / 2,210 mol / g. The weight average molecular weight (MWra) of the radical reactive organopolysiloxane determined by GPC measurement was 30,000.

(2) Synthesis of organopolysiloxane graft polymer 101.0 g of ethanol was charged into a separable flask equipped with a reflux condenser, a thermometer, a nitrogen introduction tube, and a stirring device. While stirring ethanol under reflux at 80 ° C. in a nitrogen atmosphere, the following solution (a) and solution (b) were respectively added to separate dropping funnels and dropped simultaneously over 1 hour.
Solution (a): A solution prepared by mixing 76.8 g of N, N-dimethylacrylamide (DMAAm), 19.2 g of N-tert-butylacrylamide (tBuAAm), and 96.0 g of ethanol.
Solution (b): 64.0 g of radical reactive organopolysiloxane synthesized in (1) above, 2,2′-azobis (2,4-dimethylvaleronitrile) “V-65B” (Wako Pure Chemical Industries, Ltd.) Manufactured, azo polymerization initiator) 0.03 g and ethanol 43.0 g mixed solution.

After completion of the dropwise addition, the reaction mixture was stirred at 80 ° C. for 3 hours and then cooled. The reaction time is 4 hours in total. Ethanol was removed from the reaction mixture at room temperature (25 ° C.) under reduced pressure (20 kPa) over 4 hours to obtain a mixture containing an organopolysiloxane graft polymer as a white solid. When the residual ratio of the sulfanyl group was measured by the above method, it was 3%.
The content of the polymer derived from the unsaturated monomer not bonded to the organopolysiloxane graft polymer in the mixture containing the organopolysiloxane graft polymer after completion of the reaction was measured according to the method described later for the obtained mixture. However, it was 29 mass%. The mass ratio (a / b) between the organopolysiloxane segment (a) and the polymer segment (b) derived from the unsaturated monomer was calculated by the above formula (I) and found to be 56/44. Moreover, the weight average molecular weight (MWt) measured on the conditions mentioned later was 63,000, and the molecular weight (MNg) between graft points was 2,000.
The organopolysiloxane graft polymer has the general formula (1) in which R ¹ and R ² are both methyl groups, R ³ is the formula (xii) (X ³¹ is —NHCO—, and R ³³ is the formula (xv). An alkylene group optionally containing a heteroatom, R ⁴ is a hydrogen atom, two R ⁵ are both a methyl group or one is a tert-butyl group and the other is a hydrogen atom Yes, p is 380, q is 15, and m is 27.

In addition, the weight average molecular weight (MWt) of the polymer obtained by Synthesis Example 1 was obtained by performing GPC measurement using the following conditions.
<GPC measurement conditions>
Column: Two “K-804L” (manufactured by Tosoh Corporation) connected in series.
Eluent: 1 mM dimethyldodecylamine / chloroform flow rate: 1.0 mL / min
Column temperature: 40 ° C
Detector: RI
Sample concentration and sample volume: 5 mg / mL, 500 μL

Moreover, the residual rate of the sulfanyl group was calculated | required with the following method.
In a 10 mL screw tube, 0.6 g of a 50 mass% ethanol solution of an organopolysiloxane graft polymer, 0.15 g of a 10 mass% ethanol solution of N-ethylmaleimide (Sigma Aldrich), and 0.55 g of ethanol are placed for 2 hours at room temperature. Stir. After stirring, 1 g of ethanol was added, the solution was analyzed by gas chromatography, and the amount of N-methylmaleimide was quantified. The residual amount of sulfanyl groups was calculated from the consumption rate of N-methylmaleimide, and the residual rate of sulfanyl groups was calculated from this value and the number of moles of sulfanyl groups per unit mass of the sulfanyl group-modified organopolysiloxane.

Moreover, the measurement of the content of the polymer derived from the unsaturated monomer which is not couple | bonded with the organopolysiloxane graft polymer after completion | finish of reaction was performed as follows.
After completion of the polymerization reaction, the content (% by mass) of the polymer derived from the unsaturated monomer in the mixed solution containing the organopolysiloxane graft polymer after removing the solvent was measured by liquid chromatography. The measurement conditions are shown below.

[Measurement conditions for liquid chromatography]
Detector: UV absorptiometer (measurement wavelength: 230nm)
Column: ODS column “L-column ODS” (manufactured by Chemicals Research Institute, Size: 4.6 × 150mm, 5μm)
Column temperature: constant temperature around 30 ° C. Mobile phase A: 2% phosphoric acid aqueous solution, mobile phase B: 2% phosphoric acid ethanol solution Flow rate: 0.5 mL / min
Sample concentration and sample volume: 1-2 mg / mL, 10.0 μL

Examples 1-5, Comparative Examples 1-6
An undiluted solution was prepared according to the formulation shown in Tables 1 and 2 and filled in a pressure-resistant container for aerosol together with carbon dioxide gas to obtain an aerosol type skin treatment agent.
For these aerosol-type skin treatment agents, measure the bubble duration (foam retention) according to the following method, the difficulty of dripping after discharge to the skin, the smoothness of the skin after application, and the use of hand. Sensory evaluation was performed on the sliminess of the skin. The results are also shown in Tables 1 and 2.

(Bubble duration / Bubble holding)
1 g of each composition was discharged onto the skin in a laboratory atmosphere, and the state of bubbles in the composition was visually observed, and the time from immediately after discharge until the bubbles in the composition disappeared was measured.

(The difficulty of dripping)
Sensory evaluation was conducted on the resistance to dripping after 0.2 g of each composition was discharged onto the scalp in a laboratory atmosphere. The evaluation was performed by allowing eight panelists to select one of “difficult to drip”, “difficult to drip slightly”, and “drip drip”. Show the number of panelists who answered “It is difficult to spill” / “Slightly difficult to spill” / “Spill”.

(Dry skin feeling after drying)
1 g of each composition discharged from the pressure vessel was applied onto the skin, and after 3 minutes passed, the sensory evaluation was performed on the smoothness of the skin. The evaluation was performed by allowing the eight panelists to select one of “Smooth”, “Neither”, or “Smooth”. Show the number of panelists who answered “Smooth” / “I can't say” / “I have stickiness” in order.

(No slimy hands when applied)
1 g of each composition discharged from the pressure-resistant container was applied onto the skin, and sensory evaluation was performed on the wetness of the hand when it was being blended. The evaluation was performed by allowing eight panelists to selectively select “Non-Smooth”, “Neither”, or “Smooth”. Show the number of panelists who answered "I can't say anything" / "I can't say anything" / "I'm slim".

Claims (6)

An aerosol-type skin treatment agent comprising a stock solution containing the following components (A) and (B) and component (C) carbon dioxide.
(A) An organopolysiloxane graft polymer having an organopolysiloxane segment (a) as a main chain and a polymer segment (b) derived from an unsaturated monomer as a side chain, the unsaturated monomer The polymer segment (b) derived from the body contains 50% by mass or more and 100% by mass or less of repeating units derived from N, N-dimethylacrylamide, and the polymer segment (a) in the organopolysiloxane graft polymer Organopolysiloxane graft polymer in which the mass ratio (a / b) of the polymer segment (b) derived from a saturated monomer is from 10/90 to 70/30
(B) Water The aerosol-type skin treatment agent according to claim 1, wherein the component (A) organopolysiloxane graft polymer is an organopolysiloxane graft polymer represented by the following general formula (1).

[Where,
R ¹ may be the same or different and represents an alkyl group having 1 to 8 carbon atoms;
R ² may be the same or different and represents a hydroxyl group or a hydrocarbon group having 1 to 22 carbon atoms;
R ³ represents an alkylene group which may contain a hetero atom,
R ⁴ represents a hydrogen atom or a methyl group,
R ⁵ may be the same or different and represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms which may be substituted by a hydroxyl group, an amino group or a mono- or di-C _1-4 alkylamino group,
p represents a number from 50 to 2,000, q represents a number from 3 to 50, and m represents a number from 10 to 100.
However, in the m repeating units, the ratio of the repeating units in which two R ^{5 s} are both methyl groups is 50% by mass or more and 100% by mass or less. ]   The aerosol-type skin treatment agent according to claim 1 or 2, wherein the stock solution further contains ethanol as component (D).   The aerosol type skin treatment agent according to any one of claims 1 to 3, wherein the mass ratio (C) / (A) of the component (C) to the component (A) is 2.5 or more and 50 or less.   The aerosol-type skin treatment agent according to any one of claims 1 to 4, wherein the stock solution further contains a hair-restoring component as the component (E).   The aerosol-type skin treatment agent according to any one of claims 1 to 5, wherein the content of the water-soluble thickener in the stock solution is 0.05% by mass or less.