JP7356107B2 - Oil-in-water sunscreen cosmetics - Google Patents

Description

The present invention relates to oil-in-water sunscreen cosmetics.

Sunscreen cosmetics often contain inorganic ultraviolet scattering agents. However, inorganic UV scattering agents tend to cause precipitation and aggregation, and have poor storage stability, making it difficult to obtain sufficient UV protection. Furthermore, when cosmetics containing ultraviolet scattering agents are applied to the skin, there are problems in usability such as stickiness and white cast.

In order to solve the above problems, for example, Patent Documents 1 and 2 disclose sunscreen cosmetics containing an inorganic ultraviolet scattering agent and crystalline cellulose. Further, Patent Document 3 discloses a sunscreen cosmetic containing an inorganic ultraviolet scattering agent and a specific ester oil.

However, none of the sunscreen cosmetics described in Patent Documents 1 to 3 are fully satisfactory in both storage stability and usability.

JP 2017-36254 Publication Japanese Patent Application Publication No. 2017-57180 Japanese Patent Application Publication No. 2017-78054

The present invention was developed in view of the above circumstances, and although it contains an inorganic UV scattering agent, it improves the feeling of use such as stickiness and white cast during application, and also suppresses precipitation and aggregation of the inorganic UV scattering agent. The object of the present invention is to provide an oil-in-water sunscreen cosmetic with improved UV protection ability.

As a result of intensive research to solve the above problems, the present inventors have found that by combining specific cellulose nanofibers, surfactants, and oily components with inorganic UV scattering agents, precipitation and aggregation of the UV scattering agents can be prevented. The present invention has been completed based on the findings that the UV protection ability is improved, stickiness, white cast and smearing are suppressed during application, and an excellent feeling of use is obtained.

That is, the present invention
This is an oil-in-water sunscreen cosmetic containing the following components A, B, C, and D.
Component A: Inorganic ultraviolet scattering agent Component B: Anion-modified cellulose nanofiber with an average fiber diameter of 2 to 500 nm Component C: Surfactant Component D: Oily component

Although the oil-in-water sunscreen cosmetic of the present invention contains an inorganic UV-scattering agent, it suppresses stickiness, white cast, and smearing when applied, and also prevents precipitation and aggregation of the inorganic UV-scattering agent, allowing UV rays to be absorbed by UV rays. It has improved defensive ability.

Next, the oil-in-water sunscreen cosmetic of the present invention will be explained in detail. The oil-in-water sunscreen cosmetic of the present invention contains an inorganic ultraviolet scattering agent, specific cellulose nanofibers, a surfactant, and an oily component.

The inorganic ultraviolet scattering agent (hereinafter referred to as "component A") used in the oil-in-water sunscreen cosmetic of the present invention is not particularly limited as long as it is used as an inorganic ultraviolet scattering agent in the field of cosmetics. Specific examples include titanium oxide, zinc oxide, iron oxide, cerium oxide, etc., and preferably fine particles of these, such as fine titanium oxide, fine zinc oxide, fine iron oxide, and fine cerium oxide. These can be used alone or in combination of two or more.

The above component A may be subjected to surface hydrophobization treatment. Surface hydrophobization treatment improves dispersibility in oil and water resistance, so those that have been surface hydrophobized are preferably used. Surface treatment methods include silicone treatment with methylhydrogenpolysiloxane, methylpolysiloxane, etc.; alkylsilane treatment; fluorine treatment with perfluoroalkyl phosphate, perfluoroalcohol, etc.; amino acid treatment with N-acylglutamic acid, etc.; and others. , lecithin treatment; metal soap treatment; fatty acid treatment; alkyl phosphate treatment; isostearic acid treatment and the like.

Further, the particle size of the component A is not particularly limited, but, for example, the average primary particle size is preferably 200 nm or less, more preferably 80 nm or less. If the average primary particle diameter greatly exceeds 200 nm, it tends to cause white cast or white residue. Note that the average primary particle diameter in the present invention is, for example, a value determined from a transmission electron micrograph as the arithmetic average of the long axis and short axis of the particles. The particle shape of component A is not particularly limited, and may be in the state of primary particles or in the form of agglomerated secondary aggregates. Further, shapes such as spherical, elliptical, and crushed shapes are not particularly limited.

Further, since component A is a powder, it may be blended into the oil-in-water sunscreen cosmetic of the present invention as a powder, or may be blended as a dispersion in a dispersion medium. As component A, a commercially available product can be used. Specifically, commercially available products include product names: FINEX-30W-LP2, STR-100A-LP, DIF-3W2, DIF-3W3, DIF-AW4, DIF-AW5, DIF-TL- sold by Sakai Chemical. 3W, DIF-OP-3W, DIF-3ST, DIF-3ST4S, DIF-2T2, DIF-TL-3ST, DIS-11A, DIS-61A, DIS-TL-10A, DIS-TL-10C, DIS-OP- 10A, GT-10W, GT-10W2, DIF-AB-33W, DIS-AB-10W, Product names sold by Teika: MTY-110M3S, MTY-02, MT-100TV, MT-500HSA, MT-100T, MT -01, MT-10EX, MT-05, MT-100Z, MT-150EX, MT-100AQ, MT-100WP, MT-100SA, MT-500B, MT-500SA, MT-600B, MT-500SAS, Shin-Etsu Chemical Product names sold by: SPD-T3, SPD-T5, SPD-T6, SPD-Z3, SPD-Z5, SPD-Z6, Product names sold by Ishihara Sangyo: Taipeke CR-50, Taipeke TTO-M- 1. Taipei TTO-V4, sold by Titanium Industries, product name: TD3312, TD-57A, TD-605S, ST-455, STT-65C-S, STT-30EHS, sold by Bayer, product name: Bayer Titanium R-KB-1, sold by Daito Kasei, product name: WD-Ti50, Zn-50, Zn-50V2, Zn-50V2 (DM), Zn-50V3 (DM), Zn-70-300, Zn-70 -300 (DM), Zn-50 (INS), Ti-30, Ti-45, Ti-45 (DM), Ti-45 (INS), Ti-50WN, sold by Dainippon Kasei Kogyo, product name: Examples include Cosmeserve WP-40TK, WP-40W, WP-58MP (V), WP-60SP, WP-TTN (V), WP-UF (V), WPA-STD (V)-2, etc.

Furthermore, the blending amount of component A is preferably 0.01% by mass to 50% by mass, more preferably 2% by mass to 30% by mass, based on the oil-in-water sunscreen cosmetic of the present invention.

The oil-in-water sunscreen cosmetic of the present invention contains anion-modified cellulose nanofibers (hereinafter referred to as "component B") having an average fiber diameter of 2 to 500 nm. The preferred average fiber diameter of component B is 2 to 200 nm, and the preferred aspect ratio is 20 or more. Note that the average fiber diameter, average fiber length, and aspect ratio of component B can be measured as follows.

The average fiber diameter and average fiber length are values obtained by analyzing 200 randomly selected fibers using a field emission scanning electron microscope (FE-SEM). Note that the aspect ratio is a value calculated using the following formula.

Component B in the oil-in-water sunscreen cosmetic of the present invention is obtained by defibrating anion-modified cellulose obtained by anion-modifying a cellulose raw material. Cellulose raw materials include plants (e.g., wood, bamboo, hemp, jute, kenaf, agricultural residues, cloth, pulps (softwood unbleached kraft pulp (NUKP), softwood bleached kraft pulp (NBKP), hardwood unbleached kraft pulp ( LUKP), hardwood bleached kraft pulp (LBKP), softwood unbleached sulfite pulp (NUSP), softwood bleached sulfite pulp (NBSP), thermomechanical pulp (TMP), recycled pulp, waste paper, etc.), animals (e.g. ascidians) ), algae, microorganisms (eg, acetic acid bacteria), microbial products, and the like. Among these, plants, microorganisms, etc. are preferable, and plants are more preferable.

The above-mentioned anion-modified cellulose is obtained by introducing anionic groups such as carboxymethyl groups, carboxyl groups, and phosphate ester groups into cellulose made from the above-mentioned cellulose raw materials.For example, carboxymethylated cellulose, carboxylated cellulose, and phosphoric acid ester Examples include acid esterified cellulose. These can be used alone or in combination of two or more. Moreover, among these, carboxymethylated cellulose and carboxylated cellulose are preferred, and carboxymethylated cellulose is particularly preferred because it can be used as a food additive.

Further, specific examples of methods for introducing anionic groups into cellulose include methods of introducing anionic groups into pyranose rings by oxidation reaction or substitution reaction. Examples of this oxidation reaction include a reaction in which the hydroxyl group of the pyranose ring is directly oxidized to a carboxyl group, and examples of the substitution reaction include, for example, a reaction in which an anionic group is introduced into the pyranose ring by a substitution reaction other than the oxidation. can be mentioned. Hereinafter, methods for producing carboxymethylated cellulose, carboxylated cellulose, and phosphoric acid esterified cellulose will be specifically described.

(carboxymethylated cellulose)
Carboxymethylated cellulose can be obtained by a known method. An example of the manufacturing method includes a method including the following steps i) to ii). The carboxymethylation is modification by substitution reaction. i) Mix the above-mentioned cellulose raw material, the following solvent, and the following mercerizing agent, and mercerize at a reaction temperature of 0 to 70°C, preferably 10 to 60°C, and a reaction time of 15 minutes to 8 hours, preferably 30 minutes to 7 hours. ii) Next, a carboxymethylating agent such as sodium monochloroacetate is added in moles of 0.05 to 10.0 times per glucose residue, and the reaction temperature is 30 to 90°C, preferably 40 to 80°C, and Carboxymethylated cellulose can be produced by carrying out an etherification reaction for a reaction time of 30 minutes to 10 hours, preferably 1 hour to 4 hours.

As the solvent, 3 to 20 times the amount of water or lower alcohol can be used. Specifically, a single solvent such as water, methanol, ethanol, N-propyl alcohol, isopropyl alcohol, N-butanol, isobutanol, tertiary butanol, or a mixture of two or more thereof can be used. When lower alcohol is mixed, the mixing ratio is 60 to 95% by mass.

As the mercerizing agent, an alkali metal hydroxide can be used in an amount of 0.5 to 20 times the mole per anhydroglucose residue of the cellulose raw material. Specifically, sodium hydroxide and potassium hydroxide can be used.

Further, the degree of carboxymethyl substitution per glucose unit of cellulose is preferably 0.01 to 0.50, and more preferably 0.02 to 0.35 from the viewpoint of operability. By introducing carboxymethyl substituents into cellulose, the cellulose cells become electrically repulsive to each other. Therefore, cellulose into which carboxymethyl substituents have been introduced can be easily nano-fibrillated. Note that if the carboxymethyl substituent per glucose unit is less than 0.01, nanofibrillation may not be sufficient. On the other hand, if the number of carboxymethyl substituents per glucose unit is greater than 0.50, nanofibers may not be obtained due to swelling or dissolution.

In addition, the degree of carboxymethyl substitution per glucose unit of carboxymethylated cellulose can be measured as follows. Precisely weigh about 2.0 g of carboxymethylated cellulose fiber (absolutely dry), put it in a 300 mL Erlenmeyer flask with a stopper, add 100 mL of a solution prepared by adding 100 mL of special grade concentrated nitric acid to 900 mL of methanol, and shake for 3 hours. Carboxymethylated cellulose salt (hereinafter referred to as "CM-modified cellulose") was converted to hydrogen-type CM-modified cellulose. 1.5 to 2.0 g of hydrogenated CM cellulose (absolutely dried) was accurately weighed and placed in a 300 mL Erlenmeyer flask with a stopper. The hydrogenated CM cellulose was wetted with 15 mL of 80% by mass methanol, 100 mL of 0.1N NaOH was added, and the mixture was shaken at room temperature for 3 hours. Excess NaOH was back titrated with 0.1N H ₂ SO ₄ using phenolphthalein as indicator. The degree of carboxymethyl substitution (DS) can be calculated by the following formula.

(carboxylated cellulose)
Carboxylated cellulose (hereinafter also referred to as "oxidized cellulose") can be obtained by a known method. An example of the manufacturing method includes the following method. For example, a method may be mentioned in which the above-mentioned cellulose raw material is oxidized in water using the following oxidizing agent in the presence of the following N-oxyl compound, the following bromide and/or the following iodide. Through this oxidation reaction, the primary hydroxyl group at the C6 position of the glucopyranose ring on the cellulose surface is selectively oxidized, resulting in cellulose fibers having an aldehyde group and a carboxyl group (-COOH) or a carboxylate group (-COO-) on the surface. can be obtained. The concentration of cellulose during the reaction is not particularly limited, but is preferably 5% by mass or less.

The above-mentioned N-oxyl compound refers to a compound capable of generating nitroxy radicals. As the N-oxyl compound, any compound can be used as long as it promotes the desired oxidation reaction. Examples include 2,2,6,6-tetramethylpiperidine-1-oxy radical (TEMPO, Sigma Aldrich) and its derivatives (eg 4-hydroxyTEMPO, Sigma Aldrich). The amount of the N-oxyl compound used is not particularly limited as long as it is a catalytic amount that can oxidize cellulose as a raw material. For example, it is preferably 0.01 to 10 mmol, more preferably 0.01 to 1 mmol, and even more preferably 0.05 to 0.5 mmol, per 1 g of bone dry cellulose. Further, it is preferably about 0.1 to 4 mmol/L to the reaction system.

The bromide mentioned above is a compound containing bromine, and examples thereof include alkali metal bromides that can be dissociated and ionized in water. For example, sodium bromide can be suitably used.

The above-mentioned iodide is a compound containing iodine, and examples thereof include alkali metal iodide. The amount of bromide or iodide to be used can be selected within a range that can promote the oxidation reaction. The total amount of bromide and iodide is, for example, preferably 0.1 to 100 mmol, more preferably 0.1 to 10 mmol, and even more preferably 0.5 to 5 mmol, per 1 g of bone dry cellulose.

As the above-mentioned oxidizing agent, known ones can be used, such as halogen, hypohalous acid, halous acid, perhalogenic acid, or salts thereof, halogen oxides, peroxides, and the like. Among these, sodium hypochlorite is preferred because it is inexpensive and has little environmental impact. The appropriate amount of the oxidizing agent to be used is, for example, preferably 0.5 to 500 mmol, more preferably 0.5 to 50 mmol, even more preferably 1 to 25 mmol, and most preferably 3 to 10 mmol, per 1 g of bone dry cellulose. . Further, for example, it is preferably 1 to 40 mol per 1 mol of the N-oxyl compound.

The above oxidation reaction can proceed efficiently even under relatively mild conditions. Therefore, the reaction temperature is preferably 4 to 40°C, and may be room temperature of about 15 to 30°C. As the reaction progresses, carboxyl groups are generated in the cellulose, so a decrease in the pH of the reaction solution is observed. Therefore, in order for the oxidation reaction to proceed efficiently, it is preferable to add an alkaline solution such as an aqueous sodium hydroxide solution to maintain the pH of the reaction solution at about 8 to 12, preferably about 10 to 11. Water is preferred as the reaction medium because of its ease of handling and the fact that side reactions are less likely to occur. The reaction time in the oxidation reaction can be appropriately set according to the degree of progress of the oxidation, and is usually about 0.5 to 6 hours, for example about 0.5 to 4 hours.

Further, the oxidation reaction may be carried out in two stages. For example, by oxidizing the oxidized cellulose obtained by filtration after the completion of the first-stage reaction again under the same or different reaction conditions, the efficiency can be improved without being inhibited by the salt produced as a by-product in the first-stage reaction. Can be oxidized well.

Furthermore, another example of the oxidation method for carboxylation is a method of oxidizing the cellulose raw material by bringing it into contact with a gas containing ozone. This oxidation reaction oxidizes the hydroxyl groups at at least the 2- and 6-positions of the glucopyranose ring and causes decomposition of the cellulose chain. The ozone concentration in the ozone-containing gas is preferably 50 to 250 g/m ³ , more preferably 50 to 220 g/m ³ . The amount of ozone added to the cellulose raw material is preferably 0.1 to 30 parts by mass, more preferably 5 to 30 parts by mass, when the solid content of the cellulose raw material is 100 parts by mass. The ozone treatment temperature is preferably 0 to 50°C, more preferably 20 to 50°C. The ozone treatment time is not particularly limited, but is about 1 to 360 minutes, preferably about 30 to 360 minutes. When the ozone treatment conditions are within these ranges, excessive oxidation and decomposition of cellulose can be prevented, resulting in a good yield of oxidized cellulose. After the ozone treatment, additional oxidation treatment may be performed using the following oxidizing agent. The oxidizing agent used in the additional oxidation treatment is not particularly limited, but examples thereof include chlorine-based compounds such as chlorine dioxide and sodium chlorite, oxygen, hydrogen peroxide, persulfuric acid, and peracetic acid. For example, the additional oxidation treatment can be performed by dissolving these oxidizing agents in water or a polar organic solvent such as alcohol to prepare an oxidizing agent solution, and immersing the cellulose raw material in the solution. The amount of carboxyl groups in the oxidized cellulose can be adjusted by controlling reaction conditions such as the amount of oxidizing agent added and reaction time used in the above-mentioned additional oxidation treatment.

The amount of carboxyl groups in carboxylated cellulose is not particularly limited, but is preferably 0.6 to 3.0 mmol/g, more preferably 1.0 to 2.0 mmol/g, based on the absolute dry mass of carboxylated cellulose. preferable.

The amount of carboxyl groups can be measured as follows. Prepare 60 ml of 0.5% by mass slurry (aqueous dispersion) of carboxylated cellulose, add 0.1M hydrochloric acid aqueous solution to adjust the pH to 2.5, and then dropwise add 0.05N sodium hydroxide aqueous solution to adjust the pH to 11. The electrical conductivity was measured until the electrical conductivity changed, and the amount (a) of sodium hydroxide consumed in the neutralization stage of the weak acid, in which the electrical conductivity changes slowly, was calculated using the following formula.

(phosphate esterified cellulose)
Phosphate-esterified cellulose can be obtained by a known method. Examples of the manufacturing method include a method of mixing the powder and aqueous solution of the phosphoric acid compound A described below with the cellulose raw material, a method of adding the following aqueous solution of the phosphoric acid compound A to a slurry of the cellulose raw material, and the like. Examples of the phosphoric acid compound A include phosphoric acid, polyphosphoric acid, phosphorous acid, phosphonic acid, polyphosphonic acid, and esters thereof, and these may be in the form of salts. Among these, compounds having phosphoric acid groups are preferred because they are low cost, easy to handle, and can introduce phosphoric acid groups into cellulose to improve fibrillation efficiency. Examples of compounds having a phosphoric acid group include phosphoric acid, sodium dihydrogen phosphate, disodium hydrogen phosphate, trisodium phosphate, sodium pyrophosphate, sodium metaphosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, and phosphoric acid. Examples include tripotassium acid, potassium pyrophosphate, potassium metaphosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, triammonium phosphate, ammonium pyrophosphate, and ammonium metaphosphate. A phosphoric acid group can be introduced using one type or a combination of two or more of these. Among these, phosphoric acid, sodium salt of phosphoric acid, potassium salt of phosphoric acid, phosphoric acid Ammonium salts of are preferred. Particularly preferred are sodium dihydrogen phosphate and disodium hydrogen phosphate. Furthermore, it is desirable to use the phosphoric acid compound A in the form of an aqueous solution because the reaction can proceed uniformly and the efficiency of introducing phosphoric acid groups can be increased. The pH of the aqueous solution of the phosphoric acid compound A is preferably 7 or less since this increases the efficiency of introducing phosphoric acid groups, but the pH is preferably 3 to 7 from the viewpoint of suppressing hydrolysis of cellulose.

Specific examples of the method for producing phosphoric acid esterified cellulose include the following method. The above-mentioned phosphoric acid compound A is added to a suspension of the above-mentioned cellulose raw material having a solid content concentration of 0.1 to 10% by mass with stirring to introduce phosphoric acid groups into the cellulose. When the cellulose raw material is 100 parts by mass, the amount of phosphoric acid compound A added is preferably 0.2 to 500 parts by mass, more preferably 1 to 400 parts by mass as the amount of phosphorus element. If the proportion of phosphoric acid compound A is equal to or higher than the lower limit, the yield of fine fibrous cellulose can be further improved. However, if the above upper limit is exceeded, the effect of improving the yield reaches a ceiling, which is not preferable from a cost standpoint.

Furthermore, in the production of phosphoric acid esterified cellulose, powder of compound B may be mixed in addition to the phosphoric acid compound A described above. Compound B is not particularly limited, but is preferably a nitrogen-containing compound that exhibits basicity. "Basic" herein is defined as the aqueous solution exhibiting a pink to red color in the presence of the phenolphthalein indicator, or the pH of the aqueous solution being greater than 7. The nitrogen-containing compound exhibiting basicity is preferably a compound having an amino group. Examples include urea, methylamine, ethylamine, trimethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine, pyridine, ethylenediamine, hexamethylenediamine, and the like. Among them, urea is preferred because it is low cost and easy to handle. The amount of the compound B added is preferably 2 to 1000 parts by weight, more preferably 100 to 700 parts by weight, based on 100 parts by weight of the solid content of the cellulose raw material. The reaction temperature is preferably 0 to 95°C, more preferably 30 to 90°C. The reaction time is not particularly limited, but is approximately 1 to 600 minutes, more preferably 30 to 480 minutes. When the conditions for the phosphoric acid esterification reaction are within these ranges, cellulose can be prevented from being excessively phosphoricated and become easily dissolved, and the yield of phosphoric acid esterified cellulose can be improved. After dehydrating the obtained phosphoric acid esterified cellulose suspension, it is preferably heat-treated at 100 to 170° C. from the viewpoint of suppressing hydrolysis of cellulose. Further, during heat treatment, it is preferable to heat at 130° C. or lower, preferably 110° C. or lower while water is contained, and after removing water, heat treatment at 100 to 170° C.

The degree of substitution of phosphoric acid groups per glucose unit in the phosphoric acid esterified cellulose is preferably from 0.001 to 0.40. By introducing phosphate substituents into cellulose, the cellulose cells become electrically repulsive to each other. Therefore, cellulose into which phosphate groups have been introduced can be easily nano-fibrillated. If the degree of phosphate group substitution per glucose unit is less than 0.001, sufficient nanofibrillation cannot be achieved. On the other hand, if the degree of phosphate group substitution per glucose unit is greater than 0.40, the nanofibers may not be obtained due to swelling or dissolution. In order to efficiently defibrate, the phosphorylated cellulose obtained above is preferably boiled and then washed with cold water.

Component B in the oil-in-water sunscreen cosmetic of the present invention can be obtained, for example, by nanofibrillating anion-modified cellulose using a dispersion of anion-modified cellulose adjusted to 0.1 to 10% by mass. . The device used for nano-fibrillation is not limited, but devices capable of applying a strong shearing force to the dispersion, such as a high-speed rotation type, a colloid mill type, a high pressure type, a roll mill type, and an ultrasonic type, are preferable. In order to efficiently defibrate, it is preferable to use a wet high pressure or ultra-high pressure homogenizer that can apply a pressure of 50 MPa or more to the dispersion and a strong shearing force. The pressure is more preferably 100 MPa or more, and still more preferably 140 MPa or more. Furthermore, before the defibration and dispersion treatment using a high-pressure homogenizer, if necessary, a pretreatment can be performed using a known mixing, stirring, emulsifying, and dispersing device such as a high-speed shear mixer.

Component B in the oil-in-water sunscreen cosmetic of the present invention may be blended as it is as a dispersion after the nano-fibrillation treatment, or may be blended as a dried product by performing the dehydration and drying described below. good.

The dehydration/drying method for the nano-fibrillated dispersion of the anion-modified cellulose may be any conventionally known method, such as spray drying, compression, air drying, hot air drying, and vacuum drying. Examples of specifically used drying equipment are as follows. Continuous tunnel dryer, band dryer, vertical dryer, vertical turbo dryer, multi-stage disk dryer, ventilation dryer, rotary dryer, flash dryer, spray dryer dryer, spray dryer , cylindrical drying equipment, drum drying equipment, screw conveyor drying equipment, rotary drying equipment with heating tubes, vibration transport drying equipment, etc., batch-type box drying equipment, ventilation drying equipment, vacuum box drying equipment, agitation drying equipment, etc. These drying devices can be used alone or in combination of two or more. Among these, it is preferable to use a drum dryer from the point of view of energy efficiency because thermal energy is directly and uniformly supplied to the material to be dried. Further, a drum dryer is preferable from the point of view that the dried product can be recovered immediately without applying more heat than necessary.

Further, the dried product obtained by the above dehydration/drying method may be pulverized and classified. In particular, it is preferable to perform dry pulverization or wet pulverization because the particles can be further refined. Examples of devices used for dry grinding include impact mills such as hammer mills and pin mills, media mills such as ball mills and tower mills, and jet mills. Examples of devices used in wet grinding include homogenizers, mass colloiders, pearl mills, and the like.

Component B in the oil-in-water sunscreen cosmetic of the present invention includes, in addition to those produced as described above, Nippon Paper Industries' CELLENPIA series (carboxymethylated cellulose nanofibers, carboxylated cellulose nanofibers), Commercially available products such as RHEOCRYSTA Cellulose NanofiberGel (carboxylated cellulose nanofiber) manufactured by Kogyo Seiyaku and Auro Visco (phosphoric acid esterified cellulose nanofiber) manufactured by Oji Paper may also be used.

The content of the component B is not particularly limited, but is preferably 0.001% to 5% by mass, and preferably 0.005% to 5% by mass as a solid content, based on the entire oil-in-water sunscreen cosmetic of the present invention. 1% by mass is more preferred. If the content of component B is less than 0.001% by mass as a solid content, stability may not be sufficiently improved; on the other hand, if the content of component B is less than 5% by mass as a solid content If the amount is too large, the usability as a cosmetic preparation may be impaired.

The surfactant (hereinafter referred to as "component C") used in the oil-in-water sunscreen cosmetic of the present invention is not particularly limited, and examples thereof include hydrophilic surfactants, lipophilic surfactants, and the like. These can be used alone or in combination of two or more.

The hydrophilic surfactant is not particularly limited, and examples thereof include polyglycerin fatty acid esters. Specific polyglyceryl fatty acid esters include polyglyceryl stearate-2, polyglyceryl stearate 3, polyglyceryl stearate 4, polyglyceryl stearate 5, polyglyceryl stearate 6, polyglyceryl distearate 10, polyglyceryl distearate-6 and polyglyceryl distearate 10, polyglyceryl tristearate-2, Polyglyceryl-10 decastearate, Polyglyceryl-2 isostearate, 3, 4, 5, 6, 8, 10, Polyglyceryl-2 diisostearate (diglyceryl diisostearate), 3, 10, Polyglyceryl-2 isostearate, polyglyceryl-2 tetraisostearate, polyglyceryl-10 decaisostearate, polyglyceryl-2 oleate, 3, 4, 5, 6, 8, 10, polyglyceryl-6 dioleate, Polyglyceryl-2 trioleate, polyglyceryl-10 decaoleate, diglyceryl diisostearate, polyglyceryl tetraisostearate, polyglyceryl-10 nonaisostearate, polyglyceryl-8 deca (erucic acid/isostearic acid/ricinoleic acid), (hexyldecanoic acid/sebacin) acid) diglyceryl oligoester and the like.

The lipophilic surfactant is not particularly limited, but examples thereof include fatty acid glycerin esters. Specific fatty acid glycerin esters include glyceryl stearate, glyceryl isostearate, glyceryl palmitate, glyceryl myristate, glyceryl oleate, glyceryl coconut oil fatty acid, monoglycerin cottonseed oil fatty acid, glyceryl monoerucate, glyceryl sesquioleate, α, Glycerin fatty acid partial esters such as α'-oleate glyceryl pyroglutamate, glyceryl monostearate malic acid, ethylene glycol monofatty acid esters such as ethylene glycol monostearate; propylene glycol monofatty acid esters such as propylene glycol monostearate; Erythritol partial fatty acid ester; sorbitol partial fatty acid ester; maltitol partial fatty acid ester; maltitol ether; sorbitan monooleate, sorbitan monoisostearate, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan sesquioleate , sorbitan fatty acid esters such as sorbitan trioleate, diglycerol pent-2-ethylhexylate sorbitan, diglycerol sorbitan tetra-2-ethylhexylate; sugar derivative partial esters such as sucrose fatty acid ester, methyl glucoside fatty acid ester, trehalose undecylenate; Alkyl glucosides such as caprylyl glucoside; alkyl polyglycosides; polyoxyethylene fatty acid mono- and diesters such as polyoxyethylene distearate, polyethylene glycol diisostearate, polyoxyethylene monooleate, polyoxyethylene dioleate; Polyoxyethylene/propylene glycol fatty acid ester; polyoxyethylene glycerin fatty acid ester such as polyoxyethylene monooleate such as polyoxyethylene glycerin monostearate, polyoxyethylene glycerin monoisostearate, polyoxyethylene glycerin triisostearate, etc. ; Polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan tetraoleate; polyoxyethylene sorbitan monolaurate, polyoxy Polyoxyethylene sorbitol fatty acid esters such as ethylene sorbitol monooleate, polyoxyethylene sorbitol pentaoleate, polyoxyethylene sorbitol monostearate; polyoxyethylene methyl glucoside fatty acid esters; polyoxyethylene alkyl ether fatty acid esters; polyoxyethylene sorbitol Examples include polyoxyethylene animal and vegetable oils and fats such as beeswax; alkyl glyceryl ethers such as isostearyl glyceryl ether, chimyl alcohol, cerakyl alcohol, and batyl alcohol;

The content of the component C is not particularly limited, but is preferably 0.01% to 20% by mass, more preferably 0.05% to 10% by mass of the entire oil-in-water sunscreen cosmetic of the present invention.

The oil-based component (hereinafter referred to as "component D") used in the oil-in-water sunscreen cosmetic of the present invention is not particularly limited, but may include, for example, an oil that is liquid at room temperature (25°C) and which is usually added to cosmetics. , and waxes that are solid at room temperature (25° C.) and are commonly blended into cosmetics. One or more types of these can be used. Among these, the above-mentioned wax that is solid at room temperature can be preferably used because it can be expected to have an effect of improving SPF.

Examples of oils that are liquid at room temperature include animal oils, vegetable oils, synthetic oils, volatile oils, silicones, etc., as well as hydrocarbons, fats and oils, waxes, ester oils, fatty acids, silicones, and fluorine oils. and lanolin derivatives. Specifically, liquid paraffin, squalane, pristane, paraffin, octyldodecanol, isododecane, light isoparaffin, medufoam oil, avocado oil, camellia oil, turtle oil, macadamia nut oil, corn oil, mink oil, olive oil, rapeseed oil, Egg yolk oil, sesame oil, persic oil, wheat germ oil, sasanqua oil, castor oil, linseed oil, safflower oil, cottonseed oil, eno oil, soybean oil, peanut oil, tea seed oil, kaya oil, rice bran oil, sinagiri oil, Japan Tung oil, jojoba oil, germ oil, glycerin trioctanoate, glycerin triisopalmitate, isopropyl myristate, cetyl octoate, octyldodecyl myristate, isopropyl palmitate, butyl stearate, hexyl laurate, myristyl myristate, oleic acid. Decyl, hexyldecyl dimethyloctanoate, cetyl lactate, myristyl lactate, lanolin acetate, isocetyl stearate, isocetyl isostearate, cholesteryl 12-hydroxystearate, di-2-ethylhexylate, ethylene glycol, dipentaerythritol fatty acid ester, monoisostearic acid N-alkyl glycol, neopentyl glycol dicaprate, diisostearyl malate, glycerin di-2-heptylundecanoate, trimethylolpropane tri-2-ethylhexylate, trimethylolpropane triisostearate, pentane tetra-2-ethylhexylate Erythritol, glycerin tri-2-ethylhexylate, trimethylolpropane triisostearate, cetyl 2-ethylhexanoate, 2-ethylhexyl palmitate, glycerin trimyristate, glycerin tri-2-heptylundecanoate, castor oil fatty acid methyl ester , oleic acid oil, acetoglyceride, 2-heptylundecyl palmitate, adipi-2-heptylundecyl, ethyl laurate, di-2-ethylhexyl sebacate, 2-hexyldecyl myristate, 2-hexyldecyl palmitate, 2-hexyldecyl adipic acid, diethylhexyl sebacate, diisopropyl sebacate, 2-ethylhexyl succinate, triethyl citrate, dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, decamethylpolysiloxane, dodecamethylpolysiloxane , tetramethyltetrahydrogenpolysiloxane, etc. Among these, dimethylpolysiloxane is preferred because it can be expected to have the effect of suppressing cream vanishing even in a small amount. Moreover, these can be used alone or in combination of two or more.

Examples of the wax that is solid at room temperature include oils and fats, hydrocarbon oils, higher fatty acids, and silicones. Specifically, cocoa butter, coconut oil, horse tallow, hydrogenated coconut oil, palm oil, beef tallow, mutton tallow, hydrogenated beef tallow, palm kernel oil, pork fat, beef bone tallow, Japanese oak kernel oil, hydrogenated oil, beef leg tallow. , mokuro, hydrogenated castor oil, etc. Waxes include beeswax, candelilla wax, cotton wax, carnauba wax, bayberry wax, privet wax, spermaceti wax, montan wax, bran wax, hydrogenated lanolin, kapok wax, acetic acid lanolin, liquid lanolin, sugar cane wax, lanolin fatty acid isopropyl, hexyl laurate, reduced lanolin. , Jojoba wax, hard lanolin, shellac wax, POE lanolin alcohol ether, POE lanolin alcohol acetate, POE cholesterol ether, lanolin fatty acid polyethylene glycol, POE hydrogenated lanolin alcohol ether, paraffin, ozokerite, ceresin, petrolatum, microcrystalline wax lauric acid, myristicin Acid, palmitic acid, stearic acid, behenic acid, oleic acid, 12-hydroxystearic acid, undecylenic acid, tolic acid, isostearic acid, linoleic acid, linoleic acid, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) etc. Examples of higher alcohols include lauryl alcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, myristyl alcohol, oleyl alcohol, cetostearyl alcohol, monostearyl glycerin ether (batyl alcohol), 2-decyltetradecinol, lanolin alcohol, cholesterol, and phytosterols. , hexyldodecanol, isostearyl alcohol, ozokerite, and the like. Examples of the silicone wax include alkyl(C30-45)dimethylsilylpolypropylsilsesquioxane and the like.

The content of the component D is not particularly limited, but is preferably 0.002% to 30% by mass, more preferably 0.01% to 20% by mass of the entire oil-in-water sunscreen cosmetic of the present invention.

In addition, when using a combination of an oil agent that is liquid at room temperature and a wax that is solid at room temperature as component D, the mixing ratio of these is not particularly limited, but for example, the ratio of the oil agent that is liquid at room temperature and the wax that is solid at room temperature is as follows. The visible mass ratio is preferably 9:1 to 1:2, more preferably 6:1 to 3:1. With the above blending ratio, both aggregation and precipitation of the inorganic ultraviolet scattering agent and separation of the oily component can be prevented. Note that if the blending ratio of wax that is solid at room temperature is less than the above-mentioned blending ratio, the oily component may separate.

The oil-in-water sunscreen cosmetic of the present invention contains the above-mentioned components A to D, but may contain other components as long as the effects of the present invention are not impaired. Other ingredients include, for example, pH adjusters, chelating agents, humectants, solvents, preservatives, ultraviolet absorbers, plant extracts, anti-inflammatory agents, and water-soluble agents commonly used in cosmetics and quasi-drugs. Examples include polymers, powders other than inorganic ultraviolet scattering agents, pigments, and fragrances.

The oil-in-water sunscreen cosmetic of the present invention can be prepared by a known method. A preferable preparation method is, for example, by uniformly dissolving the above components C and D and other components as necessary at 70 to 80°C, and then adding an aqueous phase heated to 70 to 80°C to emulsify. After cooling to 30 to 40° C., the above component B is added and mixed uniformly, and then component A is added and mixed.

The oil-in-water sunscreen cosmetic of the present invention thus obtained has excellent usability and storage stability, even though it contains an inorganic ultraviolet scattering agent. Therefore, the oil-in-water type sunscreen cosmetics of the present invention can be used, for example, in skin care cosmetics such as emulsions, lotions, and serums, sun care cosmetics such as sunscreens, and makeup cosmetics such as BB creams and emulsified foundations. Available. In addition, the dosage form of the oil-in-water sunscreen cosmetic of the present invention includes cream, liquid, gel, emulsion, spray, and aerosol type. Particularly preferred are water-based dosage forms.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to these Examples in any way.

Production Example 1: Production of carboxylated cellulose nanofibers:
500 g (bone dry) of bleached unbeaten kraft pulp (whiteness 85%) derived from coniferous trees was mixed with 780 mg of 2,2,6,6-tetramethylpiperidine-1-oxyradical (TEMPO (Sigma Aldrich)) and 75 mg of sodium bromide. .5 g was added to 500 ml of an aqueous solution and stirred until the pulp was uniformly dispersed. An aqueous sodium hypochlorite solution was added to the reaction system at a concentration of 6.0 mmol/g to start the oxidation reaction. During the reaction, the pH in the system decreased, but the pH was adjusted to 10 by successively adding a 3M aqueous sodium hydroxide solution. The reaction was terminated when the sodium hypochlorite was consumed and the pH within the system stopped changing. The mixture after the reaction was filtered through a glass filter to separate the pulp, and the pulp was sufficiently washed with water to obtain oxidized pulp (carboxylated cellulose). The pulp yield at this time was 90%, the time required for the oxidation reaction was 90 minutes, and the amount of carboxyl groups was 1.6 mmol/g. The oxidized pulp obtained in the above process was adjusted to 1.0% (w/v) with water and treated with an ultra-high pressure homogenizer (20°C, 150 Mpa) three times to form an aqueous dispersion of carboxylated cellulose nanofibers. (hereinafter referred to as "CNF1") was obtained. The obtained carboxylated cellulose nanofibers had an average fiber diameter of 3 nm and an aspect ratio of 250.

Production Example 2: Production of carboxymethylated (CM) cellulose nanofibers:
Add 200 g dry weight of pulp (NBKP (softwood bleached kraft pulp), Nippon Paper Industries) and 111 g dry weight of sodium hydroxide to a stirrer that can mix pulp, so that the pulp solid content is 20% (w/v). I added water to make it. Thereafter, after stirring at 30° C. for 30 minutes, 216 g (in terms of active ingredient) of sodium monochloroacetate was added. After stirring for 30 minutes, the temperature was raised to 70°C and stirred for 1 hour. Thereafter, the reactant was taken out, neutralized, and washed to obtain carboxylmethylated pulp with a degree of carboxymethyl substitution per glucose unit of 0.25. Thereafter, the carboxymethylated pulp was adjusted to a solid content of 3% with water, and was defibrated by treating it with a high-pressure homogenizer at 20°C and a pressure of 150 MPa five times. was obtained (referred to as "CNF2"). The obtained carboxymethylated cellulose nanofibers had an average fiber diameter of 50 nm and an aspect ratio of 120.

Example 1: Non-chemical sunscreen gel 1
According to the composition shown in Table 1, non-chemical sunscreen gel 1 was prepared by the following manufacturing method.

(Production method)
(1) Heat 1 to 4 to uniformly dissolve (70°C to 80°C).
(2) Heat 5 (70°C to 80°C).
(3) Gradually add (2) to (1) and emulsify (70°C to 80°C).
(4) Cool (3) (30°C to 40°C).
(5) Add 6 prepared in advance to (4) and mix uniformly.
(6) Add 7 and 8 to (5) and mix uniformly.

Example 2: Non-chemical sunscreen gel 2
According to the composition shown in Table 2, non-chemical sunscreen gel 2 was prepared by the following manufacturing method.

(Production method)
(1) Heat 1 to 5 to uniformly dissolve (70°C to 80°C).
(2) Heat 6 (70°C to 80°C).
(3) Gradually add (2) to (1) and emulsify (70°C to 80°C).
(4) Cool (3) (30°C to 40°C).
(5) Add 7 prepared in advance to (4) and mix uniformly.
(6) Add 8 and 9 to (5) and mix uniformly.

Example 3: Non-chemical sunscreen gel 3
According to the composition shown in Table 3, non-chemical sunscreen gel 3 was prepared by the following manufacturing method.

(Production method)
(1) Heat 1 to 5 to uniformly dissolve (70°C to 80°C).
(2) Heat 6 (70°C to 80°C).
(3) Gradually add (2) to (1) and emulsify (70°C to 80°C).
(4) Cool (3) (30°C to 40°C).
(5) Add 7 prepared in advance to (4) and mix uniformly.
(6) Add 8 and 9 to (5) and mix uniformly.

Example 4: BB cream According to the composition shown in Table 4, a BB cream was prepared by the following manufacturing method.

(Production method)
(1) Heat 1 to 4 to uniformly dissolve (70°C to 80°C).
(2) Heat 5 (70°C to 80°C).
(3) Gradually add (2) to (1) and emulsify (70°C to 80°C).
(4) Cool (3) (30°C to 40°C).
(5) Add 6 prepared in advance to (4) and mix uniformly.
(6) Add 7 to 9 to (5) and mix uniformly.

Example 5: Skin care cream A skin care cream was prepared according to the composition shown in Table 5 by the following manufacturing method.

(Production method)
(1) Heat 1 to 4 to uniformly dissolve (70°C to 80°C).
(2) Heat 5 (70°C to 80°C).
(3) Gradually add (2) to (1) and emulsify (70°C to 80°C).
(4) Cool (3) (30°C to 40°C).
(5) Add 6 prepared in advance to (4) and mix uniformly.
(6) Add 7 and 8 to (5) and mix uniformly.

Example 6: Skin care emulsion A skin care emulsion was prepared according to the composition shown in Table 6 by the following manufacturing method.

(Production method)
(1) Heat 1 to 4 to uniformly dissolve (70°C to 80°C).
(2) Heat 5 (70°C to 80°C).
(3) Gradually add (2) to (1) and emulsify (70°C to 80°C).
(4) Cool (3) (30°C to 40°C).
(5) Add 6 prepared in advance to (4) and mix uniformly.
(6) Add 7 and 8 to (5) and mix uniformly.

Example 7: Beauty serum A beauty serum was prepared according to the composition shown in Table 7 by the following manufacturing method.

(Production method)
(1) Heat 1 to 4 to uniformly dissolve (70°C to 80°C).
(2) Heat 5 (70°C to 80°C).
(3) Gradually add (2) to (1) and emulsify (70°C to 80°C).
(4) Cool (3) (30°C to 40°C).
(5) Add 6 prepared in advance to (4) and mix uniformly.
(6) Add 7 and 8 to (5) and mix uniformly.

Example 8: Sunscreen Cream A sunscreen cream was prepared according to the composition shown in Table 8 by the following manufacturing method.

(Production method)
(1) Heat 1 to 5 to uniformly dissolve (70°C to 80°C).
(2) Heat 6 (70°C to 80°C).
(3) Gradually add (2) to (1) and emulsify (70°C to 80°C).
(4) Cool (3) (30°C to 40°C).
(5) Add 7 prepared in advance to (4) and mix uniformly.
(6) Add 8 and 9 to (5) and mix uniformly.

Example 9: Non-chemical sunscreen gel 4
According to the composition shown in Table 9, non-chemical sunscreen gel 4 was prepared by the following manufacturing method.

(Production method)
(1) Heat 1 to 4 to uniformly dissolve (70°C to 80°C).
(2) Heat 5 (70°C to 80°C).
(3) Gradually add (2) to (1) and emulsify (70°C to 80°C).
(4) Cool (3) (30°C to 40°C).
(5) Add 6 prepared in advance to (4) and mix uniformly.
(6) Add 7 and 8 to (5) and mix uniformly.

Example 10: Non-chemical sunscreen gel 5
According to the composition shown in Table 10, non-chemical sunscreen gel 5 was prepared by the following manufacturing method.

(Production method)
(1) Heat 1 to 4 to uniformly dissolve (70°C to 80°C).
(2) Heat 5 (70°C to 80°C).
(3) Gradually add (2) to (1) and emulsify (70°C to 80°C).
(4) Cool (3) (30°C to 40°C).
(5) Add 6 prepared in advance to (4) and mix uniformly.
(6) Disperse 7 to 10 uniformly.
(7) Add (6) to (5) and mix uniformly.

Example 11: Non-chemical sunscreen gel 6
According to the composition shown in Table 11, non-chemical sunscreen gel 6 was prepared by the following manufacturing method.

(Production method)
(1) Heat 1 to 3 to uniformly dissolve (70°C to 80°C).
(2) Heat 4 (70°C to 80°C).
(3) Gradually add (2) to (1) and emulsify (70°C to 80°C).
(4) Cool (3) (30°C to 40°C).
(5) Add 5 prepared in advance to (4) and mix uniformly.
(6) Add 6 and 7 to (5) and mix uniformly.

Comparative example 1: Non-chemical sunscreen gel 7
According to the composition shown in Table 12, non-chemical sunscreen gel 7 was prepared by the following manufacturing method.

(Production method)
(1) Heat 1 to 4 to uniformly dissolve (70°C to 80°C).
(2) Heat 5 (70°C to 80°C).
(3) Gradually add (2) to (1) and emulsify (70°C to 80°C).
(4) Cool (3) (30°C to 40°C).
(5) Add 6 prepared in advance to (4) and mix uniformly.
(6) Add 7 and 8 to (5) and mix uniformly.

The usability and stability of Examples 1 to 11 and Comparative Example 1 were evaluated using the following evaluation criteria. The results are shown in Table 13.

(Evaluation criteria)
<Feeling of use>
(Rating): (Evaluation results)
3 points: very good
2 points: Fair 1 point: Poor <Stability> (Evaluation after storage at 50°C for 1 month)
◎: The inorganic UV scattering agent did not precipitate, and there was no separation of oil. ○: The inorganic UV scattering agent did not precipitate, but there was separation of oil. ×: The inorganic UV scattering agent precipitated, and there was separation of oil.

From the above results, in Comparative Example 1, the inorganic ultraviolet scattering agent aggregated and precipitated, the oil separated, and the usability was also poor. On the other hand, when Examples 1 to 11 were applied to the skin after being stored at 50° C. for one month, there was no white cast and the feeling of use was excellent. Further, in Examples 1 to 11, the inorganic ultraviolet scattering agent did not precipitate, and the stability was good. Furthermore, Examples 1 to 10 in which the ratio of the oil agent that is liquid at room temperature to the wax that is solid at room temperature is in the range of 9:1 to 1:2 prevents both the precipitation of the inorganic ultraviolet scattering agent and the separation of the oil component. The stability was particularly excellent.

Although the oil-in-water sunscreen cosmetic of the present invention contains an inorganic ultraviolet scattering agent, it can suppress white cast, stickiness, etc. when applied, and also has improved ultraviolet protection ability, so it can be used as a skin care cosmetic. , sun care cosmetics, makeup cosmetics, etc.

Claims (3)

Component A, Component B, Component C, and Component D below
Component A: Inorganic ultraviolet scattering agent Component B: Anion-modified cellulose nanofiber with an average fiber diameter of 2 to 500 nm Component C: Hydrophilic surfactant Component D: Contains an oily component,
The component A is 0.01% by mass to 30% by mass,
The component B is 0.001% by mass to 5% by mass,
The component C is a polyglycerin fatty acid ester, and it is 0.05% by mass to 10% by mass,
The component D is 0.01% by mass to 20% by mass, and the component D contains an oil agent that is liquid at room temperature and a wax that is solid at room temperature in a ratio of 9:1 to 3 : 1 .
Oil-in-water sunscreen cosmetics. The oil-in-water sunscreen cosmetic according to claim 1, wherein the component A is one or more selected from the group consisting of particulate titanium oxide, particulate zinc oxide, particulate cerium oxide, and particulate iron oxide. The oil-in-water sunscreen cosmetic according to claim 1 or 2, wherein the component B is carboxymethylated cellulose nanofibers and/or carboxylated cellulose nanofibers.