Polyglycerol fatty acid ester

Abstract

To provide a polyglycerol fatty acid ester which has excellent solubility in oils even at low temperatures such as -5°C.SOLUTION: The polyglycerol fatty acid ester comprises: a fatty acid that has 6 to 22 carbon atoms: and a polyglycerol that has an average polymerization degree of 5 to 22 and a proportion of branched glycerol groups represented by the formula (1) in the figure of 14% to 36%. The total content of glycerol and diglycerol in the polyglycerol is 2-20 mass%.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a polyglycerol fatty acid ester, a composition containing said compound, and a cosmetic preparation containing the same. [Background technology]

[0002] Polyglycerol fatty acid esters are mainly used in the food and cosmetics fields. An example of their use in the cosmetics field is an oil-based cleansing cosmetic in which polyglycerol fatty acid esters are dissolved in oil. When blending into an oil-based cleansing cosmetic, solubility in oil is an important factor. If the solubility in oil is poor, precipitation or turbidity will occur, resulting in a cosmetic with a less beautiful appearance.

[0003] Polyglycerin used in the hydrophilic group of polyglycerol fatty acid ester is generally obtained by dehydration polymerization of glycerin, and purifying it as necessary by distillation, bleaching, deodorization, ion exchange resin treatment, etc. Polyglycerin prepared by such a method causes turbidity or precipitation when the polyglycerol fatty acid ester is synthesized and dissolved in an oil agent.

[0004] In addition, one method to increase solubility in oils is to lower the HLB of the surfactant. Although lowering the HLB makes it possible to temporarily create a transparent solution, precipitation occurs during long-term storage or storage at low temperatures, so this has not yet resolved the problem.

[0005] As a technique for solving such problems, for example, Patent Document 1 discloses a method for increasing the solubility of a polyglycerol fatty acid ester in an oil by removing unreacted polyglycerol. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 7-173380 Summary of the Invention [Problem to be solved by the invention]

[0007] However, Patent Document 1 requires a step of removing unreacted polyglycerol, and the stability at low temperatures has not been evaluated, so further improvement is required.

[0008] The problem to be solved by the present invention is to provide a polyglycerol fatty acid ester which has excellent solubility in oils even at low temperatures such as -5°C. [Means for solving the problem]

[0009] The present invention relates to the following [1] to [3]. [1] A polyglycerol fatty acid ester comprising a polyglycerol having an average degree of polymerization of 5 to 22 and a polyglycerol having a ratio of branched glycerol groups represented by the following formula (1) of 14 to 36%, wherein the total content of glycerol and diglycerol in the polyglycerol is 2 to 20 mass%. [ka] [2] A cosmetic composition comprising the polyglycerol fatty acid ester according to [1] and an oil. [3] A cosmetic comprising the cosmetic composition according to [2]. Effect of the Invention

[0010] According to the present invention, it is possible to provide a polyglycerol fatty acid ester that has excellent solubility in an oil even at a low temperature such as −5° C. The solubility in the present invention is determined based on the solubility at −5° C. when the polyglycerol fatty acid ester is adjusted to a concentration of 15 mass % using cetyl ethylhexanoate as the oil, but the polyglycerol fatty acid ester of the present invention can also be used with other oils, concentrations, and temperature ranges. [Brief description of the drawings]

[0011] [Figure 1] 13C-NMR spectrum of Preparation Example 1 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present inventors have intensively studied the above problem, and have found that by giving an appropriate branch structure to polyglycerin, which is the hydrophilic group of polyglycerin fatty acid ester, and by setting the total content of glycerin and diglycerin in polyglycerin within a specific range, excellent solubility in oils is achieved, leading to the completion of the present invention. As a mechanism, it is presumed that the hydrophilic group polyglycerin has an appropriate branch structure, which makes it easier for hydrophilic groups to interact with each other when forming a reverse micelle structure. It is also considered that the presence of a specific amount of glycerin and diglycerin ester strengthens the reverse micelle structure, thereby increasing its stability.

[0013] The polyglycerol fatty acid ester of the present invention is an ester of polyglycerol having a ratio of branched glycerol groups represented by the above formula (1) of 14 to 36% and an average degree of polymerization of 5 to 22, and a fatty acid having 6 to 22 carbon atoms. The HLB of the polyglycerol fatty acid ester of the present invention is preferably 8 to 13, more preferably 9 to 13, from the viewpoint of suppressing stickiness during rinsing.

[0014] In this specification, HLB refers to the value measured by the following Griffin calculation method. vinegar The saponification number and neutralization number are measured by known methods. HLB=20(1-S / A) S: Saponification value of polyglycerol fatty acid ester A: Neutralization value of raw fatty acid

[0015] In the polyglycerol related to the polyglycerol fatty acid ester of the present invention, the ratio of the branched glycerol group represented by the above formula (1) is 14 to 36%, and the average degree of polymerization is 5 to 22, preferably 5 to 15, from the viewpoint of solubility in oil. The number of the branched glycerol groups represented by the above formula (1) per one molecule of polyglycerol is preferably 1 to 10 on average, more preferably 1 to 4 on average, from the viewpoint of solubility in oil. Here, the ratio and number of the branched glycerol groups can be adjusted by the ratio of raw materials during the production of polyglycerol. For example, in the examples described later, the ratio and number of the branched glycerol groups are increased by increasing the amount of glycerol triglycidyl ether used, and the ratio and number of the branched glycerol groups are decreased by decreasing the amount of glycerol triglycidyl ether used. The ratio and number of the branched glycerol groups are measured by the method described in the examples described later.

[0016] The average degree of polymerization of polyglycerol in this specification means the average degree of polymerization of polyglycerol calculated from the hydroxyl value by terminal group analysis, and is the average degree of polymerization calculated from (Equation 1) and (Equation 2). (Equation 1) Average degree of polymerization = (112.2 × 103 - 18 × hydroxyl value) / (74 × hydroxyl value - 56.1 × 103) (Equation 2) Hydroxyl value = (ab) x 28.05 / sample amount (g) a: Amount of 0.5N potassium hydroxide solution consumed in the blank test (ml) b: Amount of 0.5N potassium hydroxide solution consumed in this test (ml) The hydroxyl value in the above formula (1) is calculated using formula (2) in accordance with the "Standard Methods for Analysis of Fats, Oils and Related Materials (I) 1996 Edition" compiled by the Japan Oil Chemists' Society.

[0017] In addition, the polyglycerin related to the polyglycerin fatty acid ester of the present invention has a total content of glycerin and diglycerin of 2 to 20% by mass, preferably 4 to 20% by mass, from the viewpoints of solubility in oils and degree of polymerization. The total content of glycerin and diglycerin in the polyglycerin can be adjusted by adjusting the degree of purification using a column or by adding them separately after purification. The total content of glycerin and diglycerin in the polyglycerin is measured by the method described in the Examples below.

[0018] From the viewpoint of crystallinity in an oil agent, the fatty acid in the polyglycerol fatty acid ester of the present invention has a carbon number of 6 to 22. Specific examples thereof include caprylic acid, isononanoic acid, capric acid, lauric acid, isostearic acid, and oleic acid.

[0019] The polyglycerol fatty acid ester of the present invention can be prepared by esterification reaction of polyglycerol and fatty acid by a general synthesis method. Since the polyglycerol fatty acid ester of the present invention has excellent solubility in oils, it can be suitably used as a cosmetic composition containing polyglycerol fatty acid ester and oils. It can also be used in known applications of polyglycerol fatty acid esters, such as in various foods and beverages. A preferred embodiment of the cosmetic composition using the polyglycerol fatty acid ester of the present invention will be described below.

[0020] The cosmetic composition of this embodiment contains the polyglycerol fatty acid ester of the present invention and an oil agent.

[0021] The content of the polyglycerol fatty acid ester in the cosmetic composition of this embodiment is preferably 3 to 30% by mass, more preferably 5 to 20% by mass, and even more preferably 10 to 15% by mass. The polyglycerol fatty acid ester used here includes at least the polyglycerol fatty acid ester of the present invention, but other polyglycerol fatty acid esters can also be used in combination. The ratio of the polyglycerol fatty acid ester of the present invention in the polyglycerol fatty acid ester is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, and even more preferably 90 to 100% by mass. When two or more polyglycerol fatty acid esters are used, the content refers to the total amount of the polyglycerol fatty acid esters.

[0022] The oil agent in the cosmetic composition of this embodiment is not particularly limited, but examples thereof include hydrocarbon oils, ester oils, acylglycerol, ether oils, animal and vegetable oils, silicone oils, etc., and preferably hydrocarbon oils, ester oils, ether oils, and vegetable oils, and more preferably ester oils.

[0023] The hydrocarbon oil is not particularly limited, but examples thereof include hydrogenated polyisobutene, liquid paraffin, light liquid isoparaffin, squalane, undecane, tridecane, and isododecane.

[0024] Examples of ester oils include, but are not limited to, isononyl isononanoate, isostearyl isostearate, cetyl ethylhexanoate, ethylhexyl palmitate, octyldodecyl myristate, isopropyl myristate, propylheptyl caprylate, caprylyl caprylate, caprylyl caprate, coconut (caprylic acid / capric acid), dicaprylyl carbonate, and the like.

[0025] Examples of acylglycerols include, but are not limited to, caprylic / capric glycerides, caprylic / capric triglycerides, triethylhexanoin, glyceryl triisostearate, and glyceryl diisostearate.

[0026] The ether oil is not particularly limited, but examples thereof include dicaprylyl ether.

[0027] Examples of animal and vegetable oils include, but are not limited to, beeswax, avocado oil, almond oil, olive oil, wheat germ oil, rice germ oil, rice bran oil, safflower oil, soybean oil, corn oil, rapeseed oil, palm oil, palm kernel oil, castor oil, sunflower oil, jojoba oil, macadamia nut oil, coconut oil, and lanolin. Preferred examples include avocado oil, almond oil, olive oil, wheat germ oil, rice germ oil, rice bran oil, safflower oil, soybean oil, corn oil, rapeseed oil, castor oil, sunflower oil, jojoba oil, and macadamia nut oil.

[0028] Examples of silicone oils include, but are not limited to, dimethicone, phenyl trimethicone, cyclomethicone, cyclopentasiloxane, and diphenylsiloxyphenyl trimethicone.

[0029] The content of the oil in the cosmetic composition of this embodiment is preferably 70 to 97% by mass, more preferably 80 to 95% by mass, and even more preferably 85 to 90% by mass. When two or more types of oil are used, the content of the oil refers to the total amount of the oils.

[0030] In addition to the above-mentioned components, the cosmetic composition of this embodiment can contain other components that are normally used in cosmetics, as appropriate, depending on the application and purpose. Examples of such optional components include water, surfactants, polyhydric alcohols, aqueous gelling agents, oily gelling agents, UV absorbers, powders, antioxidants, preservatives, fragrances, colorants, chelating agents, cooling agents, thickeners, plant extracts, vitamins, neutralizing agents, moisturizing agents, anti-inflammatory agents, pH adjusters, amino acids, etc.

[0031] The surfactant is not particularly limited, but examples thereof include polyoxyethylene fatty acid esters, polyoxyethylene glycerin fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkyl ethers, polyoxyethylene (hydrogenated) castor oil, and the like.

[0032] Examples of polyhydric alcohols include, but are not limited to, glycerin, diglycerin, ethylhexylglycerin, 1,3-butylene glycol (BG), propylene glycol (PG), propanediol, dipropylene glycol (DPG), pentylene glycol, 1,2-hexanediol, caprylyl glycol, 1,10-decanediol, isopentyldiol, sorbitol, mannitol, maltitol, and xylitol.

[0033] The cosmetic composition of this embodiment can be prepared by mixing the above-mentioned components in a conventional manner.

[0034] The cosmetic composition of this embodiment can be suitably used in various cosmetic preparations. That is, the present invention also provides a cosmetic preparation containing the cosmetic composition of this embodiment. Here, the cosmetic composition of this embodiment may be used as a cosmetic preparation as it is, or may further contain the above-mentioned optional components to form a cosmetic preparation.

[0035] Examples of the cosmetic include oil-based cosmetic, emulsion-type cosmetic, bicontinuous cosmetic, etc., and oil-based cosmetic is preferred. For example, cleansing cosmetics such as cleansing oil, cleansing balm, hot cleansing balm, cleansing gel, hot cleansing gel, cleansing gel pack, massage cosmetics such as massage oil, massage oil gel, massage scrub gel, hot massage gel, bath additives, etc.

[0036] The method for producing a cosmetic preparation includes a production method that includes a step of incorporating each of the above-mentioned components. Here, the "step of incorporating each of the above-mentioned components" includes a mode in which a cosmetic preparation composition prepared in advance is added, as well as a mode in which each of the above-mentioned components is individually blended to prepare the cosmetic preparation. EXAMPLES

[0037] EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these.

[0038] Polyglycerol Production Example 1 100g of glycerin and an alkali catalyst were added to a three-neck flask equipped with a Dimroth and a stirrer, and the temperature was raised to 120°C. 28.26g of glycerin triglycidyl ether was added dropwise at a rate of 10g / hr, and the reaction was continued for another hour after the completion of the addition. The mixture was then passed through an ion exchange resin column to remove unreacted glycerin. The obtained fraction was concentrated to obtain polyglycerin 1.

[0039] Polyglycerol Production Example 2 100g of glycerin and an alkali catalyst were added to a three-neck flask equipped with a Dimroth and a stirrer, and the temperature was raised to 120°C. 47.1g of glycerin triglycidyl ether was added dropwise at a rate of 10g / hr, and the reaction was continued for another hour after the completion of the addition. The mixture was then passed through an ion exchange resin column to remove unreacted glycerin. The obtained fraction was concentrated to obtain polyglycerin 2.

[0040] Polyglycerol Production Example 3 100g of diglycerin and an alkali catalyst were added to a three-neck flask equipped with a Dimroth and a stirrer, and the temperature was raised to 140°C. 19.56g of glycerin triglycidyl ether was added dropwise at a rate of 10g / hr, and the reaction was continued for another hour after completion of the addition. The mixture was then passed through an ion exchange resin column to remove unreacted diglycerin. The obtained fraction was concentrated to obtain polyglycerin 3.

[0041] Polyglycerol Production Example 4 100g of diglycerin and an alkali catalyst were added to a three-neck flask equipped with a Dimroth and a stirrer, and the temperature was raised to 140°C. 39.13g of glycerin triglycidyl ether was added dropwise at a rate of 10g / hr, and the reaction was continued for another hour after completion of the addition. The mixture was then passed through an ion exchange resin column to remove unreacted diglycerin. The obtained fraction was concentrated to obtain polyglycerin 4.

[0042] Polyglycerol Production Example 5 100g of diglycerin and an alkali catalyst were added to a three-neck flask equipped with a Dimroth and a stirrer, and the temperature was raised to 140°C. 78.26g of glycerin triglycidyl ether was added dropwise at a rate of 10g / hr, and the reaction was continued for another hour after completion of the addition. The mixture was then passed through an ion exchange resin column to remove unreacted diglycerin. The obtained fraction was concentrated to obtain polyglycerin 5.

[0043] Polyglycerol Production Example 6 100g of glycerin and an alkali catalyst were added to a three-neck flask equipped with a Dimroth and a stirrer, and the temperature was raised to 140°C. 141.3g of glycerin triglycidyl ether was added dropwise at a rate of 10g / hr, and the reaction was continued for another hour after completion of the addition. The mixture was then passed through an ion exchange resin column to remove unreacted glycerin. The obtained fraction was concentrated to obtain polyglycerin 6.

[0044] Polyglycerin 7, 8 In addition, "Polyglycerin #750" manufactured by Sakamoto Pharmaceutical Industry Co., Ltd. was used as polyglycerin 7, and "Polyglycerin #500" manufactured by Sakamoto Pharmaceutical Industry Co., Ltd. was used as polyglycerin 8.

[0045] Polyglycerol Production Example 9 100g of glycerin and an alkali catalyst were added to a three-neck flask equipped with a Dimroth and a stirrer, and the temperature was raised to 120°C. 28.26g of glycerin triglycidyl ether was added dropwise at a rate of 10g / hr, and the reaction was continued for another hour after the completion of the addition. The mixture was then passed through an ion exchange resin column twice to remove as much unreacted glycerin as possible. The obtained fraction was concentrated to obtain polyglycerin 9.

[0046] Polyglycerol Production Examples 10-13 Glycerin or diglycerin was added to polyglycerin 9 to prepare a solution having the contents shown in Table 1.

[0047] <Measurement of branched glycerol ratio and number of branched glycerols per molecule> The ratio of branched glycerol and the number of branched glycerols per molecule were calculated by 13C-NMR as follows. The results are shown in Table 1. As a representative example of 13C-NMR spectra, the 13C-NMR spectrum of polyglycerol 1 is shown in Figure 1. Pretreatment: Dissolve 200 mg of polyglycerin in 0.6 mL of heavy water. Equipment used: 800MHz 13C-NMR, JEOL Ltd., "JNM-ECZ800R" Number of times accumulated: 256 Measurement conditions: Temperature 30°C, measurement sequence single pulse 1H decoupling, pulse repetition time 7 seconds, acetone measured as standard peak (δ: 30.89 ppm) Peak ranges used for integration: Total Integrals(TI):60.0-83.0ppm Dendritic (D): 76.5-80.0 ppm

[0048] How to calculate the branched glycerol ratio TI is the integral value of all carbon atoms involved in polyglycerol, and D is the integral value of secondary carbon atoms involved in branched glycerol. The proportion (%) of branched glycerol is calculated from the integral values ​​of each peak above using the following formula: Ratio of branched glycerol (%) = (D × 3 / TI) × 100

[0049] How to calculate the number of branched glycerol units per molecule The number of branched glycerols per polyglycerol molecule is calculated by the following formula: Number of branched glycerols per molecule = (D × 3 / TI) × average degree of polymerization

[0050] <Measurement of glycerin and diglycerin content> The content of glycerin and diglycerin in polyglycerin was measured by converting polyglycerin into a derivative by trimethylsilylation, and then isolating and quantifying the polyglycerin derivative by GC (gas chromatography). The results are shown in Table 1. Equipment used: GC-14B (Shimadzu Corporation) Column: OL-17 (50% phenylmethyl silicone, GL Sciences Inc.) Column size: 0.5m x 3mm Measurement temperature: 100→300℃ Heating rate: 10℃ / min

[0051] [Table 1]

[0052] Preparation of polyglycerol fatty acid esters Examples 1 to 14, 16 to 17, Comparative Examples 1 to 11, 13 to 15 As shown in Tables 2 to 4, polyglycerol fatty acid esters were prepared in each of the Examples and Comparative Examples. The preparation method of Example 1 will be described in more detail as a representative example. 20.3 g of polyglycerol 1 obtained in Polyglycerol Production Example 1, 19.7 g of oleic acid, and an alkali catalyst were added to a four-neck flask equipped with a stirrer, and an esterification reaction was carried out at 260°C. The reaction was continued until the acid value of the reaction product became 0.5 or less, to obtain the polyglycerol fatty acid ester of Example 1. Other Examples and Comparative Examples were also prepared in the same manner. In Examples 10 to 14 and Comparative Examples 8 to 11, the esterification reaction was carried out at 240°C.

[0053] <Test Example 1: Temperature Stability> The polyglycerol fatty acid esters of Examples 1 to 14, 16 to 17 and Comparative Examples 1 to 11, and 13 to 15 were dissolved in the oils shown in Tables 2 to 4 by heating at 70°C to the concentrations (5% by mass, 15% by mass) shown in Tables 2 to 4. 10 g of the dissolved compositions were placed in a vial (volume 20 ml, inner diameter 2.5 cm), and the appearance properties after storage at -5°C, 25°C, and 50°C for one month were visually observed according to the following evaluation criteria. The results are shown in Tables 2 to 4. (Evaluation Criteria) 〇: No turbidity or precipitation is observed △: Slight turbidity is observed ×: Precipitated

[0054] Details of the components listed in Tables 2 to 4 are shown below. Cetyl ethylhexanoate: Exepar HO / Kao Corporation Caprylic / capric triglyceride: Sunoil MCT-7 / Taiyo Kagaku Co., Ltd. Mineral oil: MORESCO White P-70 / MORESCO Corporation

[0055] [Table 2]

[0056] [Table 3]

[0057] [Table 4]

[0058] Example 15, Comparative Example 12 Compositions were prepared in the proportions shown in Table 5, and designated as Example 15 and Comparative Example 12. Evaluations were carried out for temperature stability, particle size upon rinsing, and eye irritation for each composition. The temperature stability was evaluated in the same manner as in Test Example 1. The results are shown in Table 5.

[0059] <Test Example 2: Emulsion particle size when washed off> For Example 15 and Comparative Example 12, the emulsion was dissolved in cetyl ethylhexanoate at 70°C to a concentration of 15% by mass. After cooling to room temperature, 1 g was placed in a vial (volume 100 ml, inner diameter 3.2 cm). After adding 99 g of water and mixing, the particle size distribution was measured using a particle size distribution analyzer (BECKMAN COULTER LS 13 320). The average diameter was determined as the emulsion particle diameter when washed off. The results are shown in Table 5.

[0060] <Test Example 3: Eye irritation> For Example 15 and Comparative Example 12, the solution was dissolved in cetyl ethylhexanoate at 70°C to a concentration of 15% by mass. After cooling to room temperature, an appropriate amount was applied to the eye area and eye irritation was evaluated according to the following evaluation criteria. The evaluation was performed by five expert panelists, and the average value was calculated. The results are shown in Table 5. (Evaluation Criteria) 1: My eyes don't hurt 2: Slight eye pain 3: My eyes hurt

[0061] [Table 5]

[0062] As shown in Tables 2 to 5, all of Examples 1 to 17 using the polyglycerol fatty acid esters of the present invention had excellent temperature stability over a wide temperature range, including a low temperature such as -5° C. In addition, as shown in Table 5, the emulsion particle size upon rinsing was small and eye irritation was minimal, making them suitable for use in various cosmetic applications. [Industrial Applicability]

[0063] INDUSTRIAL APPLICABILITY According to the present invention, a polyglycerol fatty acid ester having excellent solubility in oils over a wide temperature range can be provided, and can be suitably used in applications such as cosmetics.

Claims

1. A polyglycerol fatty acid ester which is an ester of a polyglycerol having a ratio of branched glycerol groups represented by the following formula (1) of 14 to 36% and an average degree of polymerization of 5 to 22 with a fatty acid having 6 to 18 carbon atoms (excluding fatty acids having 6 to 12 carbon atoms), the total content of glycerol and diglycerol in the polyglycerol being 2 to 20 mass%, and which has an HLB of 8 to 13. 【Chemistry 1】

2. 2. The polyglycerol fatty acid ester according to claim 1, wherein the number of the branched glycerol groups per one polyglycerol molecule is 1 to 10 on average.

3. 2. The polyglycerol fatty acid ester according to claim 1, wherein the fatty acid is isostearic acid or oleic acid.

4. A cosmetic composition comprising the polyglycerol fatty acid ester according to any one of claims 1 to 3 and an oil agent.

5. A cosmetic comprising the cosmetic composition according to claim 4.

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