JP7495665B2 - Ceramide-containing composition - Google Patents

Description

The present invention relates to a ceramide-containing composition that can improve the dispersibility of ceramide in aqueous preparations, easily solubilize semirads, and provide cosmetics containing the composition that are highly transparent and have excellent low-temperature stability, and that are less sticky when applied and less foaming when filled.

Ceramides are contained in the intercellular lipids of the stratum corneum of the skin, and contribute to the skin's barrier function and moisturizing function. There have been many attempts to use these properties to apply them to cosmetics as functional ingredients, but because ceramides have very low solubility in solvents and a high melting point, it has been difficult to prepare a stable formulation that maintains transparency in aqueous formulations such as lotions.

In light of this background, Patent Document 1 provides a method for solubilizing ceramides with excellent stability by combining a nonionic surfactant and a polyhydric alcohol, and a composition for incorporation into topical skin preparations in which ceramides are transparently solubilized. Patent Document 2 provides a preparation with a liquid crystal structure suitable for use as a topical skin preparation by combining a higher alcohol, a polyglycerol fatty acid ester, and a polyhydric alcohol, and a method for producing the same. Patent Document 3 provides a transparent liquid composition that stably contains ceramide and is free of crystal precipitation by combining a polyglycerol fatty acid ester, a fatty acid monoglyceride, an oil, and a polyhydric alcohol, and provides a cosmetic that can exert the inherent moisturizing effect of ceramide.

JP 2002-338459 A JP 2004-331594 A JP 2011-073992 A

In recent years, from the viewpoint of energy saving and cost reduction, there is a demand for cosmetics that can be solubilized and manufactured in a short time with weak stirring force without using a homomixer or the like. However, with conventional technology, although cosmetics containing ceramide have excellent transparency, they have poor dispersibility in water, and in some cases, the manufacturing time for solubilization may be long or strong stirring force may be required. In addition, the surfactant that solubilizes ceramide may cause foaming when filling a container or during transportation. When filling a formulation into a container with a small capacity, it is necessary to precisely control the filling amount, but there is a problem that the liquid amount may be shifted due to bubbles. In order to suppress this foaming during filling, it is necessary to slow down the filling speed or extend the filling time until the foam disappears. Therefore, there is a demand for cosmetics that have excellent dispersibility in water, can be easily solubilized in a short time with weak stirring force, and cause little foaming during filling, and there has been no proposal that can achieve both high transparency, excellent low-temperature stability, and a good usability with less stickiness when applied.

The present invention aims to provide a ceramide-containing composition that can improve the dispersibility of ceramide in aqueous preparations, easily solubilize semirad, and produce a cosmetic composition containing the composition that has high transparency and excellent low-temperature stability, and is less sticky when applied and less foaming when filled.

As a result of intensive research in light of the above, the present inventors have found that the above object can be achieved by using ceramides, specific nonionic surfactants, polyhydric alcohols, and the like.

That is, the present invention is as follows.
(1) A ceramide-containing composition comprising the following components: 0.1 to 10% by mass of component (A), 15 to 50% by mass of component (B), 1 to 20% by mass of component (C), and 25 to 75% by mass of component (D):

(A) Ceramides

(B) a nonionic surfactant represented by the following formula (1):

R ¹ -O-(AO)a-[(PO)b/(EO)c]-H ... (1)

(In formula (1),
R ¹ represents a linear or branched alkyl group having 12 to 36 carbon atoms;
AO is an oxyalkylene group having 3 or 4 carbon atoms;
PO is an oxypropylene group;
EO is an oxyethylene group;
a, b and c are the average molar numbers of the oxyalkylene group AO, the oxypropylene group PO and the oxyethylene group EO added per molecule, respectively, and are 1≦a≦40, 1≦b≦40, 1≦c≦80 and (a+b+c)≧20,
[(PO)b/(EO)c] represents a polyoxyalkylene group in which the oxypropylene groups PO and the oxyethylene groups EO are randomly bonded to each other,
The random rate x is 0.1≦x<1.

(C) A nonionic surfactant represented by the following formula (2): R ² -O-(PO)d-(EO)eH ... (2)

(In formula (2),
^R2 represents a linear or branched alkyl group having 12 to 36 carbon atoms;
PO is an oxypropylene group;
EO is an oxyethylene group;
d and e are the average number of moles of the oxypropylene group PO and the oxyethylene group EO added per molecule, respectively, and 1≦d≦80 and 1≦e≦40,
(PO)d-(EO)e represents a polyoxyalkylene group in which the oxypropylene group PO and the oxyethylene group EO are bonded in a block shape.

(D) Polyhydric alcohol

(2) The ceramide-containing composition according to (1), further comprising 5 to 40 mass % of the following component (E):

(E) An alkylene oxide derivative represented by the following formula (3):

R ³ -{O(PO)f(EO)g-(BO)hH}i... (3)

(In formula (3),
^R3 is a residue obtained by removing all hydroxyl groups from a compound having 1 to 4 hydroxyl groups,
i is 1 to 4;
PO is an oxypropylene group;
EO is an oxyethylene group;
BO is an oxyalkylene group having 4 carbon atoms;
f, g and h are the average addition mole numbers of the oxypropylene group PO, the oxyethylene group EO and the oxyalkylene group BO having 4 carbon atoms, respectively, and are 1≦f≦40, 0≦g≦40, 0≦h≦3 and (f+g+h)×i≧8,
When the total amount of the oxypropylene group PO and the oxyethylene group EO is 100 parts by mass, the mass ratio of the oxypropylene group PO is 25 to 100 parts by mass, and when g is 1 or more, the oxypropylene group PO and the oxyethylene group EO are bonded randomly.

According to the present invention, the dispersibility of ceramide in aqueous preparations can be improved, so that semirad can be easily solubilized, and a cosmetic containing the composition can be obtained that has high transparency and excellent low-temperature stability, and is a ceramide-containing composition that is less sticky when applied and less foaming when filled.

Each component constituting the ceramide-containing composition of the present invention will be described below.
<Component (A): Ceramides>
One of the features of the present invention is the use of ceramides as component (A).

The ceramides in the present invention include ceramides and their derivatives. They may be natural extracts or synthetic products. The ceramides in the present invention are not limited as long as they can be generally used in cosmetics and the like, but can be defined as follows.
The ceramides in the present invention are a series of ceramides expressed as nonionic amphiphilic substances having one or more long-chain linear and/or branched alkyl or alkenyl groups in the molecule, and further at least two or more hydroxyl groups, one or more amide groups (and/or amino groups), or derivatives in which a phosphatidylcholine residue or a sugar residue is bound to the hydroxyl group of the nonionic amphiphilic substance. For example, natural ceramides such as sphingosine, phytosphingosine, and their long-chain fatty acid amides, such as ceramide 1, ceramide 2, ceramide 3, ceramide 3B, ceramide 4, ceramide 5, ceramide 6, ceramide 6I, and ceramide 6II; sphingophospholipids such as sphingomyelin and phytosphingomyelin, which are phospholipid derivatives of sphingosine and phytosphingosine; sphingoglycolipids and phytosphingolipids such as cerebrosides and gangliosides, which are glycosides of the above, and the like. Among these, ceramide 2 and N-stearoyldihydroxysphingosine are particularly preferred.

The content of component (A) in the composition of the present invention is 0.1 to 10 mass%. From the viewpoints of transparency and low-temperature stability, 0.5 to 5 mass% is preferred, and 1 to 3 mass% is particularly preferred. However, the total mass of components (A), (B), (C), (D), and (E) is taken to be 100 mass%.

<Component (B) Nonionic Surfactant>
Component (B) is an alkylene oxide derivative represented by the following formula (1): Component (B) may be used alone or in combination of two or more kinds.

R ¹ -O-(AO)a-[(PO)b/(EO)c]-H ... (1)

In formula (1), R ¹ represents a linear or branched alkyl group having 12 to 36 carbon atoms. If R ¹ has fewer than 12 carbon atoms, the transparency of the composition may decrease, so the number is set to 12 or more, preferably 18 or more, and particularly preferably 20 or more. If R ¹ has more than 36 carbon atoms, stickiness may occur during application, so the number is set to 36 or less, preferably 32 or less, and particularly preferably 26 or less.

The alkylene oxide derivative of formula (1) is usually produced using an alcohol, and R ¹ in formula (1) is derived from the alcohol (R ¹ OH) used in the production of the alkylene oxide derivative of formula (1). Such an alcohol is a linear or branched alcohol having 12 to 36 carbon atoms.

Examples of the alcohol (R ¹ OH) include linear alcohols such as dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, eicosanol, docosanol, tetracosanol, hexacosanol, octacosanol, triacosanol, and hexatriacosanol; and branched alcohols such as isotridecanol, 1-methylheptadecanol, 2-octyldecanol, 2-decyltetradecanol, 2-tetradecyloctadecanol, and 2-hexadecyleicosanol. One or more of these alcohols can be used when producing the alkylene oxide derivative of formula (1).
Among these alcohols, from the viewpoints of stickiness during application and transparency, branched alcohols are preferred, and isotridecanol, 1-methylheptadecanol, 2-octyldecanol, and 2-decyltetradecanol are particularly preferred.

In formula (1), AO is an oxyalkylene group having 3 or 4 carbon atoms, and examples thereof include an oxypropylene group, an oxyisobutylene group, an oxy1-ethylethylene group, an oxy2-butylene group, and an oxytetramethylene group. AO is preferably an oxypropylene group. When the average number of moles of AO added, a, is 2 or more, the two or more AO may be the same type of group or different types of groups. When AO is two or more types of different groups, they may be added in either a random manner or a block manner.

PO in formula (1) is an oxypropylene group, and EO is an oxyethylene group. a, b, and c in formula (1) are the average number of moles of AO, PO, and EO added per molecule, respectively.

a is a number from 1 to 40. The upper limit of a is preferably 30, particularly preferably 20, and more preferably 10. The lower limit of a is preferably 2, particularly preferably 3, and more preferably 4. If a is too small or too large, the transparency of the appearance may decrease.

b is a number from 1 to 40. The upper limit of b is preferably 30, particularly preferably 20, and more preferably 10. The lower limit of b is preferably 2, particularly preferably 3, and more preferably 4. If b is too small or too large, dispersibility in water may decrease.

c is a number from 1 to 80. The upper limit of c is preferably 60, particularly preferably 40, and even more preferably 30. The lower limit of c is preferably 5, particularly preferably 10, and even more preferably 20. If c is too small or too large, stickiness may occur during application.

The sum of the above a, b, and c (a+b+c) is 20 or more, preferably 30 or more, and particularly preferably 35 or more. If (a+b+c) is too small, the transparency and low-temperature stability may decrease. From the viewpoint of ease of handling, (a+b+c) is preferably 100 or less, particularly preferably 80 or less, even more preferably 50 or less, and even more preferably 40 or less.

The bond between EO and PO in formula (I) is written as [(PO)b/(EO)c], which indicates that in the present invention, b moles of PO and c moles of EO are bonded randomly, not in a block form. If EO and PO are bonded in a block form, transparency will decrease, and stickiness during application and foaming during filling may occur.

In addition, when the number of carbon atoms in ^R1 is n, the value of y represented by y = (2n + a) is preferably 30 ≦ y ≦ 100, more preferably 30 ≦ y ≦ 80, particularly preferably 35 ≦ y ≦ 80, and further preferably 40 ≦ y ≦ 60.

In the alkylene oxide derivative of formula (1), the random ratio is 0.1≦x<1, preferably 0.3≦x≦0.97, particularly preferably 0.5≦x≦0.9, further preferably 0.6≦x≦0.85, and more preferably 0.7≦x≦0.8, where x is the random ratio. If the random ratio x is too small, the transparency and low-temperature stability may decrease.

The random ratio in the alkylene oxide derivative of formula (1) can be calculated from the average added mole numbers a, b, and c of AO, EO, and PO per molecule in formula (1) according to the following formula (4).

x = (b + c) / (a + b + c) ... (4)

The alkylene oxide derivative of formula (1) can be produced by a known method. For example, an alkylene oxide is addition-polymerized to a linear or branched alkyl alcohol having 12 to 36 carbon atoms in the presence of an alkali catalyst at 50 to 160°C and 0.5 MPa (gauge pressure) or less, and then a mixture of ethylene oxide and propylene oxide is addition-polymerized, neutralized with an acid such as hydrochloric acid, phosphoric acid, or acetic acid, and then moisture and neutralized salts are removed to obtain the alkylene oxide derivative of formula (I).

The content of component (B) is 15 to 50% by mass. If the content of component (B) is too low, the transparency and low-temperature stability will be poor, and if the content is too high, stickiness will occur during application and dispersibility may be poor. From this viewpoint, the content of component (B) is preferably 20 to 45% by mass, and particularly preferably 25 to 45% by mass. However, the total mass value of components (A), (B), (C), (D), and (E) is 100% by mass.

<Component (C): Nonionic Surfactant>
Component (C) is an alkylene oxide derivative represented by the following formula (2): Component (C) may be used alone or in combination of two or more kinds.

R ² -O-(PO)d-(EO)e-H ... (2)

In formula (2), ^R2 represents a linear or branched alkyl group having 12 to 36 carbon atoms. If the carbon number of ^R2 is less than 12, the transparency and low-temperature stability of the composition may decrease, so the carbon number is set to 12 or more, preferably 18 or more, and particularly preferably 20 or more. If the carbon number of ^R2 exceeds 36, stickiness may occur during application, so the carbon number is set to 36 or less, preferably 32 or less, and particularly preferably 26 or less.

The alkylene oxide derivative of formula (2) is usually produced using an alcohol, and R ² in formula (2) is derived from the alcohol (R ² OH) used in the production of the alkylene oxide derivative of formula (2). Such an alcohol is a linear or branched alcohol having 12 to 36 carbon atoms.

Examples of the alcohol (R ² OH) include linear alcohols such as dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, eicosanol, docosanol, tetracosanol, hexacosanol, octacosanol, triacosanol, and hexatriacosanol; and branched alcohols such as isotridecanol, 1-methylheptadecanol, 2-octyldecanol, 2-decyltetradecanol, 2-tetradecyloctadecanol, and 2-hexadecyleicosanol. Among these, branched alcohols are preferred, and 2-decyltetradecanol is more preferred. One or more of these alcohols can be used when producing the alkylene oxide derivative of formula (2).

PO is an oxypropylene group, and EO is an oxyethylene group. d and e in formula (2) are the average number of moles of PO and EO added per molecule, respectively.

d is a number from 1 to 80. The upper limit of d is preferably 50, particularly preferably 40, and more preferably 30. The lower limit of d is preferably 3, particularly preferably 5, and more preferably 8. If d is too small or too large, transparency and low-temperature stability may decrease.

e is a number from 1 to 40. The upper limit of e is preferably 35, particularly preferably 25, and more preferably 15. The lower limit of e is preferably 2, particularly preferably 3, and more preferably 5. If e is too small, the transparency and low-temperature stability will decrease, and if it is too large, stickiness may occur during application.

The bond between EO and PO in formula (2) is written as (PO)d-(EO)e, which indicates that in the present invention, d moles of PO and e moles of EO are bonded in a block shape.

The HLB (hydrophile-lipophile-balance) of the nonionic surfactant represented by formula (2) is preferably 4 to 10, particularly preferably 5 to 8, from the viewpoints of ease of dispersion in water and stickiness during application. The HLB is represented by IOB×10 in the organic conceptual diagram. The IOB in the organic conceptual diagram refers to the ratio of the inorganic value (IV) to the organic value (OV) in the organic conceptual diagram, that is, "inorganic value (IV)/organic value (OV)".
The organic conceptual diagram was proposed by Atsushi Fujita, and the details thereof are described in "Pharmaceutical Bulletin", 1954, vol. 2, pp. 163-173; "Chemical Domain",
1957, vol. 11, 10, pp. 719-725, etc.

The alkylene oxide derivative represented by formula (2) can be produced by a known method. For example, the alkylene oxide derivative represented by formula (2) can be obtained by addition-polymerizing propylene oxide with a linear or branched alkyl alcohol having 12 to 36 carbon atoms in the presence of an alkali catalyst at 50 to 160°C and 0.5 MPa (gauge pressure) or less, then addition-polymerizing ethylene oxide, neutralizing the resulting mixture with an acid such as hydrochloric acid, phosphoric acid, or acetic acid, and then removing water and neutralization salts.

The content of component (C) is 1 to 20% by mass. If the content of component (C) is too low, the transparency and low-temperature stability will be poor, and if the content is too high, stickiness may occur during application. From this viewpoint, 2 to 15% by mass is preferable, and 5 to 12% by mass is particularly preferable.

<Component (D): Polyhydric alcohol>
One of the features of the present invention is the use of a polyhydric alcohol as component (D).

Specific examples of polyhydric alcohols include ethylene glycol, propylene glycol, dipropylene glycol, 1,3-butylene glycol, pentylene glycol, hexylene glycol, glycerin, diglycerin, glucose, maltose, and sorbitol. Dipropylene glycol, 1,3-butylene glycol, pentylene glycol, and hexylene glycol are preferred, and dipropylene glycol and pentylene glycol are particularly preferred. These components (D) may be used alone or in appropriate combination of two or more.

The content of component (D) is 25 to 75% by mass. If the content of component (D) is too low, dispersibility in water will be poor, and if the content is too high, stickiness may occur when applied. 30 to 70% by mass is preferred, and 33 to 68% by mass is particularly preferred.

<Component (E): Alkylene oxide derivative>
The composition of the present invention contains 5 to 40 mass % of an alkylene oxide derivative represented by the following formula (3) as component (E), thereby improving transparency and low-temperature stability and providing a good usability without stickiness upon application.

R ³ -{O(PO)f(EO)g-(BO)hH}i ... (3)

In the above formula (3), ^R3 is a residue obtained by removing all hydroxyl groups from a compound having one or more carbon atoms and 1 to 4 hydroxyl groups. i is the number of hydroxyl groups in the compound of ^R3 , and is 1 to 4. In other words, the chemical formula of the above compound having 1 to 4 hydroxyl groups is ^R3 (OH)i.

Examples of the compound R ³ (OH)i having 1 to 9 hydroxyl groups include methanol, ethanol, propanol, and butanol when i=1, ethylene glycol, propylene glycol, and hexylene glycol when i=2, glycerin and trimethylolpropane when i=3, and erythritol, pentaerythritol, sorbitan, and alkyl glucosides when i=4. These may also be used in combination. Among these, butanol, glycerin, and alkyl glucosides are preferred, and glycerin is more preferred.

f is the average number of moles of PO added, and from the viewpoint of stickiness during application, it is 1≦f≦40, preferably 1≦f≦20, and more preferably 1≦f≦5.

g is the average number of moles of EO added, and from the viewpoint of transparency and low-temperature stability, 0≦g≦40, preferably 2≦g≦20, and more preferably 2≦g≦10.

When the total amount of PO and EO is 100 parts by mass, the mass ratio of PO is 25 to 100% by mass. From the viewpoint of stickiness during application, the mass ratio of PO is set to 25% by mass or more, preferably 30% by mass or more, and more preferably 40% by mass or more. The mass ratio of PO is preferably 70% by mass or less, and more preferably 60% by mass or less.

From the viewpoint of stickiness during application, when the average number of moles of EO added, m, is greater than 0, PO and EO must be bonded randomly.

BO is an oxyalkylene group having 4 carbon atoms, specifically an oxy(1-ethylethylene) group, an oxy(1,1-dimethylethylene) group, or an oxy(1,2-dimethylethylene) group. BO is particularly preferably an oxy(1-ethylethylene) group derived from 1,2-butylene oxide.

h is the average number of moles of BO added, and 0≦h≦3. From the viewpoint of transparency and low-temperature stability, h is set to 3 or less, and more preferably 2 or less. Also, h is preferably 1 or more. In formula (1), if h is not 0, it is necessary that (BO)h is bonded to a terminal hydrogen atom.

The number of moles of EO, PO, and BO added satisfies the relationship (f+g+h)×i≧8. ((f+g+h)×i corresponds to the total number of moles of EO, PO, and BO added. From the viewpoint of stickiness during application, (f+g+h)×i is preferably 8 to 150, and more preferably 8 to 80.)

The alkylene oxide derivative represented by the above formula (3) can be produced by a known method. For example, it can be obtained by addition-polymerizing ethylene oxide and propylene oxide to a compound having one or more hydroxyl groups, and then reacting with an alkylene oxide having four carbon atoms. However, BO must be reacted after the addition-polymerization of EO and PO.

When the composition of the present invention contains component (E), the content of component (E) is preferably 5 to 40% by mass. From the viewpoints of transparency, low-temperature stability, and stickiness during application, the content is preferably 10 to 35% by mass, more preferably 15 to 35% by mass, and particularly preferably 15 to 30% by mass. However, the total mass of components (A), (B), (C), (D), and (E) is 100% by mass.

By setting the ratio of the mass of component (B) to the mass of component (C) ((B)/(C)) to 1 to 10, it becomes easier to obtain a ceramide-containing composition that is excellent in transparency and low-temperature stability. From this viewpoint, (B)/(C) is preferably 1 to 7, more preferably 2 to 5, and particularly preferably 3 to 4.

(Other Additives)
In addition to the ceramide-containing composition of the present invention, the cosmetic of the present invention may be appropriately blended with additives commonly used in cosmetics as necessary.The additives are not particularly limited as long as they do not interfere with the object of the present invention, and include, for example, oils, surfactants, moisturizing agents, thickeners, coloring materials, alcohols, UV protection agents, amino acids, vitamins, whitening agents, organic acids, inorganic salts, enzymes, antioxidants, stabilizers, preservatives, bactericides, anti-inflammatory agents, skin activators, blood circulation promoters, antiseborrheic agents, anti-inflammatory agents, sequestering agents, pH adjusters, astringents, cooling agents, fragrances, and pigments.

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. The blend amounts in the examples are in "mass %".

<Component (A)>
Component (A): Ceramide 2

<Synthesis Example 1: Synthesis of Component (B-1)>
100 g of isotridecanol and 2.0 g of potassium hydroxide as a catalyst were charged into an autoclave, and the air in the autoclave was replaced with dry nitrogen, and the catalyst was dissolved at 140° C. while stirring. Then, 232 g of propylene oxide was dropped from a dropping device at 120° C. and 0.2 to 0.5 MPa (gauge pressure), and the mixture was stirred for 3 hours. Then, a mixture of 528 g of ethylene oxide and 145 g of propylene oxide was dropped from a dropping device at 120° C. and 0.2 to 0.5 MPa (gauge pressure), and the mixture was stirred for 2 hours. Thereafter, the reaction composition was taken out of the autoclave, neutralized with hydrochloric acid to a pH of 6 to 7, and treated at 100° C. for 1 hour under a reduced pressure of −0.095 MPa (gauge pressure) in order to remove the contained moisture. Furthermore, filtration was carried out to remove the salt generated after the treatment, and component (B-1) was obtained.
In addition, the number average molecular weights of the ethylene oxide and propylene oxide adducts were determined from the hydroxyl value obtained by a hydroxyl value measurement in accordance with JIS K1557-1, and the values of a, b, and c in formula (1) were determined from the number average molecular weights, and the random ratio x was further calculated.

Synthesis Example 2: Synthesis of Components (B-2) to (B-3), (B'-1), and (B'-2)
Components (B-2) to (B-3) and (B'-1) to (B'-2) were obtained by the same synthesis method as in Synthesis Example 1, except that the starting materials and the amounts of ethylene oxide and propylene oxide added were changed.

For components (B-1) to (B-3) and (B'-1) to (B'-2), the starting material, type of alkylene oxide, average number of moles added of alkylene oxide, ethylene oxide and propylene oxide (a, b, c), total number of average moles added (a+b+c), y, b/c and random ratio x are shown in Table 1.

<Synthesis Example 3: Synthesis of component (C-1)>
250 g of lauryl alcohol and 2.0 g of potassium hydroxide as a catalyst were charged into an autoclave, and the air in the autoclave was replaced with dry nitrogen, and the catalyst was dissolved at 140° C. while stirring. Subsequently, 468 g of propylene oxide was dropped from a dropping device at 120° C. and 0.2 to 0.5 MPa (gauge pressure), and the mixture was stirred for 3 hours. Subsequently, 295 g of ethylene oxide was dropped from a dropping device at 120° C. and 0.2 to 0.5 MPa (gauge pressure), and the mixture was stirred for 2 hours. Thereafter, the reaction composition was taken out of the autoclave, neutralized with hydrochloric acid to a pH of 6 to 7, and treated at 100° C. for 1 hour under a reduced pressure of −0.095 MPa (gauge pressure) in order to remove the contained moisture. Furthermore, filtration was performed to remove the salt generated after the treatment, and component (C-1) was obtained.
Further, the number average molecular weights of the ethylene oxide and propylene oxide adducts were calculated from the hydroxyl value obtained by a hydroxyl value measurement in accordance with JIS K1557-1, and the values of d and e in formula (2) were determined from the number average molecular weights.

<Synthesis Example 4: Synthesis of Components (C-2), (C-3), and (C-4)>
Components (C-2), (C-3) and (C-4) were obtained by the same synthesis method as in Synthesis Example 3, except that the starting materials and the amounts of ethylene oxide and propylene oxide added were changed.

Synthesis Example 5: Synthesis of component (C'-1)
250 g of lauryl alcohol and 2.0 g of potassium hydroxide as a catalyst were charged into an autoclave, and the air in the autoclave was replaced with dry nitrogen, and the catalyst was dissolved at 140° C. with stirring. Subsequently, 468 g of propylene oxide was dropped using a dropping device at 120° C. and 0.2 to 0.5 MPa (gauge pressure), and the mixture was stirred for 3 hours. Thereafter, the reaction composition was removed from the autoclave, neutralized with hydrochloric acid to a pH of 6 to 7, and treated at 100° C. for 1 hour under a reduced pressure of −0.095 MPa (gauge pressure) in order to remove the contained moisture. Furthermore, filtration was performed to remove the salt generated after the treatment, and component (C′-1) was obtained.
Further, the number average molecular weight of the propylene oxide adduct was calculated from the hydroxyl value obtained by a hydroxyl value measurement according to JIS K1557-1, and the value of d was determined from the number average molecular weight.

Synthesis Example 6: Synthesis of component (C'-2)
300 g of 2-decyltetradecanol and 2.0 g of potassium hydroxide as a catalyst were charged into an autoclave, and the air in the autoclave was replaced with dry nitrogen, and the catalyst was dissolved at 140° C. with stirring. Subsequently, a mixture of 298 g of ethylene oxide and 736 g of propylene oxide was dropped at 120° C. and 0.2 to 0.5 MPa (gauge pressure) and stirred for 2 hours. Thereafter, the reaction composition was removed from the autoclave, neutralized with hydrochloric acid to a pH of 6 to 7, and treated at 100° C. for 1 hour under a reduced pressure of −0.095 MPa (gauge pressure) in order to remove the contained water. Furthermore, filtration was performed to remove the salt generated after the treatment, and component (C′-2) was obtained.
Further, the number average molecular weights of the ethylene oxide and propylene oxide adducts were calculated from the hydroxyl value obtained by a hydroxyl value measurement according to JIS K1557-1, and the values of d and e were determined from the number average molecular weights.

For components (C-1) to (C-4), (C'-1), and (C'-2), the starting materials, the type of alkylene oxide, and the average number of moles (d, e) added of alkylene oxide, ethylene oxide, and propylene oxide are shown in Table 2.

<Component (D)>
Component (D-1): 1,3-butylene glycol Component (D-2): dipropylene glycol Component (D-3): pentylene glycol

<Synthesis Example 7: Synthesis of component (E-1)>
74 g of 1-butanol and 4 g of potassium hydroxide as a catalyst were charged into an autoclave, and the air in the autoclave was replaced with dry nitrogen, after which the catalyst was completely dissolved at 140° C. with stirring. Next, a mixture of 396 g of ethylene oxide and 580 g of propylene oxide was added dropwise using a dropping device. Thereafter, the reaction composition was removed from the autoclave, and the pH was neutralized with hydrochloric acid, and the reaction composition was treated at a reduced pressure of −0.095 MPa (gauge pressure) and 100° C. for 1 hour in order to remove the contained moisture. After the treatment, filtration was further carried out to remove the salt produced, and component (E-1) was obtained.

<Synthesis Example 8: Synthesis of component (E-2)>
92 g of glycerin and 6 g of potassium hydroxide as a catalyst were charged into an autoclave, and the air in the autoclave was replaced with dry nitrogen, and the catalyst was completely dissolved at 140° C. while stirring. Next, a mixture of 308 g of ethylene oxide and 290 g of propylene oxide was dropped using a dropping device, and the mixture was stirred for 2 hours. Furthermore, 216 g of butylene oxide was dropped using a dropping device, and the mixture was reacted by stirring for 2 hours. Thereafter, the reaction composition was taken out of the autoclave, neutralized with hydrochloric acid to a pH of 6 to 7, and treated at a reduced pressure of −0.095 MPa (gauge pressure) and 100° C. for 1 hour to remove the contained moisture. Further, filtration was performed to remove the salt generated after the treatment, and component (E-2) was obtained.

The component (E)-3) shown in Table 3 was synthesized in the same manner as in Synthesis Example 8. The starting materials, the type of alkylene oxide, and the average number of moles (f, g, h) added of ethylene oxide, propylene oxide, and butylene oxide are shown in Table 3.

<Examples 1 to 13>
Ceramide-containing compositions and water-diluted solutions of the ceramide-containing compositions were prepared by the following methods using the compositions shown in Tables 4 and 5. They were then evaluated for ease of dispersion in water, transparency, low-temperature stability, stickiness upon application, and low foaming, and the results are shown in Tables 4 and 5.

<Comparative Examples 1 to 9>
Ceramide-containing compositions and water-diluted solutions of the ceramide-containing compositions were prepared by the following method using the compositions shown in Table 6. Then, the easiness of dispersion in water, transparency, low-temperature stability, stickiness upon application, and low foaming were evaluated, and the results are shown in Table 6.

<Preparation method>
Step I: Components (A), (B), (C), (D), and (E) in each table were placed in a beaker and stirred at 80° C. until homogenous, to obtain a ceramide-containing composition.
Step II: 80°C water was measured into a screw tube (mouth inner diameter x body diameter x total length: φ20.3 x φ40 x 120 mm), and a specified amount of the ceramide-containing composition prepared in step I was added while stirring at 300 rpm using a stirrer (φ8 x 25 mm), and stirring was continued until the mixture was homogenous. Stirring was continued until no precipitate or floating matter was found by visual inspection. The mixture was cooled to room temperature while stirring, and a water dilution of the ceramide-containing composition was prepared.

<Ease of dispersing in water>
When preparing a water-diluted solution of the ceramide-containing composition using the method shown in Step II, the solution was judged to be homogeneous when no precipitate or floating matter was visible to the naked eye. The stirring time required to achieve homogeneity was measured, and the ease of dispersion in water was evaluated according to the following criteria.

⊚: After the ceramide-containing composition was added, it was dispersed immediately and became uniform.
◯: After the addition of the ceramide-containing composition, it took 1 minute or more and 5 minutes or less for the mixture to become uniform.
Δ: After the addition of the ceramide-containing composition, it took 5 minutes or more for the mixture to become homogenous, or the mixture did not become homogenous and precipitates or suspended matter remained.

<Transparency>
50 mL of the water dilution of the prepared ceramide-containing composition was filled into a 100 cc glass container, and the appearance of the sample immediately after preparation was confirmed. Through the glass container containing the sample, the legibility of a character ("a": 1 cm square: MS Gothic font) at a distance of 5 cm was evaluated.

◎: Transparent and clearly legible ○: Cloudy but legible △: Characters are not visible and are milky

<Low temperature stability>
50 mL of the water-diluted solution of the prepared ceramide-containing composition was placed in a transparent glass container, sealed, and stored for one month at 0° C. After one month, the appearance of the samples stored at each temperature was observed and evaluated according to the following criteria.

○: No change in appearance of the sample after storage ×: Change in appearance of the sample after storage, such as separation

<Sticky when applied>
0.5 g of the water-diluted solution of the prepared ceramide-containing composition was applied to the forearm of 10 panelists, and a sensory evaluation of the stickiness of the sample was performed according to the following criteria.

3 points: The panelists felt almost no stickiness and the texture was good.
2 points: The panelists felt it was slightly sticky.
1 point: The panelists felt it was very sticky.

Furthermore, the total score of the evaluations by the 10 panelists was judged according to the following criteria.

◎: 25 points or more ○: 20 points or more, less than 25 points △: Less than 20 points

<Low foaming>
The degree of foaming during filling was evaluated using a vortex mixer (Scientific Industries). 50 mL of the water dilution of the ceramide-containing composition was weighed into a 100 mL screw tube (mouth inner diameter x body diameter x total length: φ20.3 x φ40 x 120 mm) and stirred at 3000 rpm for 10 seconds. The height of the foam was observed immediately after stirring and 30 seconds later, and was evaluated according to the following criteria.

(Foam height immediately after mixing)
◎: The foam is less than 8 mm immediately after dropping. ◯: The foam is less than 15 mm immediately after dropping. △: The foam is 15 mm or more immediately after dropping.

(Foam height after 30 seconds of stirring)
⊚: Less than 8 mm of foam after 30 seconds of dropping. ◯: Less than 15 mm of foam after 30 seconds of dropping. △: More than 15 mm of foam after 30 seconds of dropping.

The ceramide-containing compositions of Examples 1 to 13, which were based on the composition of the present invention, had excellent dispersibility in water, excellent transparency when diluted with water, and excellent low-temperature stability, were not sticky when applied, had a good feel, and produced little foaming.

The ceramide-containing compositions of Comparative Examples 1 to 9, which have compositions different from those of the present invention, were inferior to the ceramide-containing compositions of Examples 1 to 13 in any one of dispersibility in water, transparency and low-temperature stability when diluted in water, stickiness upon application, and foaming.

That is, in Comparative Example 1, although the content of component (B) is small, the low temperature stability and transparency are low.
In Comparative Examples 2 and 3, the component (B) was not used, but the transparency and low temperature stability were low.
In Comparative Example 4, the content of component (B) was high, but stickiness and foaming were observed upon application.
In Comparative Example 5, component (B) was not used, but dispersibility in water was low, and stickiness and foaming were observed upon application.
In Comparative Examples 6, 7 and 8, the component (C) was not used, but the low temperature stability, transparency and the like were poor.
In Comparative Example 9, components (B) and (C) were not used, but dispersibility in water was low, and stickiness and foaming were observed upon application.

Claims (2)

A ceramide-containing composition comprising the following components: 0.1 to 10 mass% of component (A), 15 to 50 mass% of component (B), 1 to 20 mass% of component (C), and 25 to 75 mass% of component (D):

(A) Ceramides

(B) a nonionic surfactant represented by the following formula (1):

R ¹ -O-(AO)a-[(PO)b/(EO)c]-H ... (1)

(In formula (1),
R ¹ represents a linear or branched alkyl group having 12 to 36 carbon atoms;
AO is an oxyalkylene group having 3 or 4 carbon atoms;
PO is an oxypropylene group;
EO is an oxyethylene group;
a, b and c are the average molar numbers of the oxyalkylene group AO, the oxypropylene group PO and the oxyethylene group EO added per molecule, respectively, and are 1≦a≦40, 1≦b≦40, 1≦c≦80 and (a+b+c)≧20,
[(PO)b/(EO)c] represents a polyoxyalkylene group in which the oxypropylene groups PO and the oxyethylene groups EO are randomly bonded to each other,
The random rate x is 0.1≦x<1.

(C) A nonionic surfactant represented by the following formula (2): R ² -O-(PO)d-(EO)eH ... (2)

(In formula (2),
^R2 represents a linear or branched alkyl group having 12 to 36 carbon atoms;
PO is an oxypropylene group;
EO is an oxyethylene group;
d and e are the average number of moles of the oxypropylene group PO and the oxyethylene group EO added per molecule, respectively, and 1≦d≦80 and 1≦e≦40,
(PO)d-(EO)e represents a polyoxyalkylene group in which the oxypropylene group PO and the oxyethylene EO group are bonded in a block shape.

(D) Polyhydric alcohol
The ceramide-containing composition according to claim 1, further comprising 5 to 40 mass % of the following component (E):

(E) An alkylene oxide derivative represented by the following formula (3):

R ³ -{O(PO)f(EO)g-(BO)hH}i... (3)

(In formula (3),
^R3 is a residue obtained by removing all hydroxyl groups from a compound having 1 to 4 hydroxyl groups,
i is 1 to 4;
PO is an oxypropylene group;
EO is an oxyethylene group;
BO is an oxyalkylene group having 4 carbon atoms;
f, g and h are the average addition mole numbers of the oxypropylene group PO, the oxyethylene group EO and the oxyalkylene group BO having 4 carbon atoms, respectively, and are 1≦f≦40, 0≦g≦40, 0≦h≦3 and (f+g+h)×i≧8,
When the total amount of the oxypropylene group PO and the oxyethylene group EO is 100 parts by mass, the mass ratio of the oxypropylene group PO is 25 to 100 parts by mass, and when g is 1 or more, the oxypropylene group PO and the oxyethylene group EO are bonded randomly.