Branched organopolysiloxane and method for producing same

Abstract

To provide a branched organopolysiloxane compound that has excellent compatibility with polar oils and the like and that can serve as a substitute for conventional low-molecular-weight siloxanes, and to provide a production method with which the branched organopolysiloxane is easily obtained at high purity.SOLUTION: A branched organopolysiloxane is represented by the following formula (1) (where R1 independently represents a C1-3 alkyl group, R2 represents a C2-3 alkyl group, R3 represents a C1-3 alkyl group. n represents 1 or 2, and m represents an integer of 0-3 with n=1, while m represents 0 or 1 with n=2. The bonding order of siloxane units may be block or random).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a branched organopolysiloxane and a method for producing the same. [Background technology]

[0002] Many organopolysiloxanes with 6 or less silicon atoms are highly volatile and highly compatible with organic compounds. Therefore, they have been used as substitutes for organic solvents and oils for cosmetics (Patent Document 1). Among them, cyclic polysiloxanes with 4 to 6 silicon atoms are used in many applications due to the ease of synthesis. However, in recent years, concerns have been raised about the impact of the above-mentioned cyclic polysiloxanes on the environment and safety.

[0003] In addition, linear organopolysiloxanes having 6 or less silicon atoms and branched tristrimethylsiloxymethylsilane are also used in various applications. However, low molecular weight organopolysiloxanes having 3 or less silicon atoms have the problem of being highly irritating to the skin, and are not particularly suitable for cosmetic applications. Furthermore, these linear and branched organopolysiloxanes are often produced by hydrolysis. Therefore, problems have arisen with the generation of the low molecular weight siloxanes and the laborious process of separating multiple products.

[0004] In addition, the above-mentioned organopolysiloxane has a problem that it is poorly compatible with polar oils that are blended into cosmetics, and cannot be mixed transparently, which may impair the feeling of use and stability of the cosmetics. This tendency is more pronounced when an organic UV absorber is used. In addition, if the organopolysiloxane has a low affinity with oily components such as waxes that are blended into cosmetics for the purpose of solidifying them, it will hinder the crystallization of the oily components, making it impossible to obtain the expected hardness of the preparation.

[0005] Patent Document 2 discloses a method for producing branched tetrasiloxane with high purity, in which a trialkoxysilane compound is added to a mixture of a disiloxane compound, an alcohol, and an acid catalyst to react with each other, and water is then added to carry out co-hydrolysis. However, when the disiloxane is substituted with an alkyl group having two or more carbon atoms, the cleavage of the siloxane bond by the acid catalyst is difficult to occur, and the yield tends to decrease. This causes problems such as the need to use a large amount of acid catalyst.

[0006] There have been reported examples of the synthesis of branched tetrasiloxane compounds in which the number of carbon atoms in the alkyl group bonded to the silicon atom, which is the branch point, is 2 or more (Patent Document 2). However, there have been no examples of the synthesis of compounds in which the number of carbon atoms in the alkyl group of the terminal trialkylsiloxy group is 2 or more. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2001 / 015658 [Patent Document 2] JP 2004-352677 A Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a branched organopolysiloxane which can be used as a substitute for conventional low molecular weight siloxanes and has good compatibility with polar oils, etc. Another object of the present invention is to provide a method for easily producing the branched organopolysiloxane with high purity. [Means for solving the problem]

[0009] As a result of intensive research aimed at achieving the above object, the present inventors discovered that the branched organopolysiloxane of the present invention has excellent compatibility with various organic compounds and is suitable for use as a variety of solvents and oils in cosmetics, which led to the completion of the present invention.

[0010] Accordingly, the present invention provides a branched organopolysiloxane and a method for producing the same. 1.The following formula (1) [ka] (In the formula, R 1 are independently alkyl groups having 1 to 3 carbon atoms, and R 2 are independently alkyl groups having 2 or 3 carbon atoms; R 3 are independently an alkyl group having 1 to 3 carbon atoms. n is 1 or 2, and when n=1, m is an integer of 0 to 3, and when n=2, m is 0 or 1. The bonding order of each siloxane unit is not limited to the above, and the bonding state of the siloxane units may be in a block or random form. The branched organopolysiloxane is represented by the formula: 2. The branched organopolysiloxane according to 1, having a boiling point at 10 hPa in the range of 87 to 119°C. 3. In the above formula (1), R 1 is a methyl group or an ethyl group, R 2 is an ethyl group, R 3 3. The branched organopolysiloxane according to 1 or 2, wherein is a methyl group, n is 1, and m is 0. 4.The following formula (2) [ka] (In the formula, R 4 are independently a hydrogen atom or the above R 1 R 5 are independently a hydrogen atom or the above R 3 Here, m and n are the same as those in the formula (1), the bonding order of the siloxane units is not limited to the above, and the bonding state of the siloxane units may be in a block or random form. 2. A method for producing the branched organopolysiloxane according to 1, comprising a hydrosilylation reaction step of reacting an organohydrogenpolysiloxane represented by the following formula: Effect of the Invention

[0011] According to the present invention, it is possible to provide a branched organopolysiloxane which can be used as a substitute for conventional low molecular weight siloxanes and has good compatibility with polar oils, etc., and this branched organopolysiloxane is suitable for use as various solvents and oils in cosmetics. It is also possible to provide a production method for easily obtaining the branched organopolysiloxane with high purity. [Brief description of the drawings]

[0012] [Figure 1] 1 is a chart of the 1H-NMR spectrum of the branched organopolysiloxane synthesized in Synthesis Example 1. [Diagram 2] 1 is a chart of the 29Si-NMR spectrum of the branched organopolysiloxane synthesized in Synthesis Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present invention will be described in detail below. I. Branched Organopolysiloxane The branched organopolysiloxane of the present invention is represented by the following formula (1): [ka] (In the formula, R 1 are independently alkyl groups having 1 to 3 carbon atoms, and R 2 are independently alkyl groups having 2 or 3 carbon atoms; R 3 are independently an alkyl group having 1 to 3 carbon atoms. n is 1 or 2, and when n=1, m is an integer of 0 to 3, and when n=2, m is 0 or 1. The bonding order of each siloxane unit is not limited to the above, and the bonding state of the siloxane units may be in a block or random form. It is expressed as follows.

[0014] R 1 R is independently an alkyl group having 1 to 3 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, and an n-propyl group. Among these, a methyl group or an ethyl group is preferable. 2 are each independently an alkyl group having 2 or 3 carbon atoms, and specific examples thereof include an ethyl group and an n-propyl group. Among these, an ethyl group is preferred. 3 are each independently an alkyl group having 1 to 3 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, and an n-propyl group. Among these, a methyl group or an ethyl group is preferred. n is 1 or 2, and preferably 1. When n=1, m is an integer of 0 to 3, and preferably an integer of 0 to 2. When n=2, m is 0 or 1, and preferably 0. The bonding order of each siloxane unit is not limited to the above, and the bonding state of the siloxane units may be in a block or random form.

[0015] In the above formula (1), R 1 is a methyl group or an ethyl group, R 2 is an ethyl group, R 3 A branched organopolysiloxane in which is a methyl group, n is 1, and m is 0 is preferred. Such a branched organopolysiloxane provides a cosmetic that is light to the touch and spreads well, particularly when blended into a cosmetic. The cosmetic also has excellent water repellency and a uniform cosmetic film. Furthermore, it does not give a strong oily feeling and achieves a good feel when used. Even when blended with various oils such as silicones, hydrocarbon oils, and esters, oily components that are solid at 25°C, or organic ultraviolet absorbers, it is possible to obtain a cosmetic that has excellent stability over time and cosmetic durability.

[0016] Examples of the branched organopolysiloxane represented by the above formula (1) include the following. [ka]

[0017] In addition, the branched organopolysiloxane of the present invention preferably has a boiling point at 10 hPa in the range of 87 to 119°C. Within this range, the handleability is particularly excellent, and when incorporated into a cosmetic, the cosmetic does not give a dry feeling when applied to the skin, and does not give a strong oily feeling after application. If the boiling point is less than 87°C, the evaporation rate is fast and there is a risk of giving a dry feeling. Furthermore, by making the boiling point less than 119°C, the oily feeling is less likely to be felt. In the present invention, the boiling point is the equilibrium reflux boiling point measured by a method in which a sample is heated at 10 hPa and the internal temperature in a state in which reflux is repeated at a rate of several drops per second is recorded.

[0018] The kinematic viscosity of the branched organopolysiloxane of the present invention at 25°C is 2.0 to 6.0 mm 2 / s is preferable, 2.2 to 3.5 mm 2 The viscosity is a value measured at 25° C. using a Cannon-Fenske viscometer described in JIS Z8803:2011.

[0019] The branched organopolysiloxane of the present invention has good compatibility with polar oils, etc. Examples of polar oils include organic UV absorbers such as ethylhexyl methoxycinnamate and octocrylene, and has particularly excellent compatibility with ethylhexyl methoxycinnamate.

[0020] II. Method for Producing Branched Organopolysiloxane The branched organopolysiloxane of the present invention can be, for example, one having the following steps. This production method makes it possible to easily obtain the branched organopolysiloxane of the above formula (1) with high purity. [ka] (In the formula, R 4 are independently a hydrogen atom or the above R 1 R 5 are independently a hydrogen atom or the above R 3Here, m and n are the same as those in the formula (1), the bonding order of the siloxane units is not limited to the above, and the bonding state of the siloxane units may be in a block or random form. and an alkene having 2 or 3 carbon atoms.

[0021] R 4 are independently a hydrogen atom or the above R 1 Specific examples of R include a hydrogen atom, a methyl group, an ethyl group, and an n-propyl group. 5 are independently a hydrogen atom or the above R 3 Specifically, the alkenes include a hydrogen atom, a methyl group, an ethyl group, and an n-propyl group. Here, m and n are the same as those in the above formula (1). Examples of the alkenes having 2 or 3 carbon atoms include ethylene and propylene.

[0022] The compounding ratio of the organohydrogenpolysiloxane represented by the above formula (2) to the alkene having 2 or 3 carbon atoms is preferably 1.0 to 2.0, and more preferably 1.0 to 1.2, in terms of the molar ratio of the alkene having 2 or 3 carbon atoms to 1 mole of the hydrosilyl group in the above formula (2).

[0023] The hydrosilylation reaction is preferably carried out in the presence of a platinum catalyst or a rhodium catalyst, and specifically, chloroplatinic acid, alcohol-modified chloroplatinic acid, chloroplatinic acid-vinylsiloxane complex, etc. The amount of catalyst used may be a catalytic amount, and in particular the amount of platinum or rhodium is preferably 50 ppm or less, more preferably 20 ppm or less, relative to the amount of the organohydrogenpolysiloxane represented by the above formula (2).

[0024] The hydrosilylation reaction may be carried out without a solvent, or an organic solvent may be used as necessary. Examples of the organic solvent include aromatic hydrocarbons such as toluene and xylene, aliphatic or alicyclic hydrocarbons such as n-pentane, n-hexane and cyclohexane, cyclic ether compounds such as tetrahydrofuran and dioxane, and ketones such as acetone and methyl ethyl ketone. Among them, it is preferable to carry out the hydrosilylation reaction without a solvent, or to carry out the hydrosilylation reaction using a hydrocarbon or an ether compound as an organic solvent.

[0025] The hydrosilylation reaction conditions are not particularly limited, but it is preferable to carry out the reaction at 40 to 100° C. for 1 to 10 hours while introducing gaseous ethylene or propylene into or out of the liquid in a reaction vessel.

[0026] III. Cosmetics Since the branched organopolysiloxane has good compatibility with polar oils, it is suitable for use as various solvents and oils in cosmetics. When the branched organopolysiloxane of the present invention is blended in cosmetics, the blending amount is not particularly limited, and is appropriately blended in the range of 0.01 to less than 100 mass%. The formulation type, use, optional ingredient blending, and blending amount are not particularly limited, and known ones can be appropriately selected. In particular, since it has excellent compatibility with ethylhexyl methoxycinnamate, it is suitable for sunscreen preparations such as sunscreens. It has also been revealed that the cosmetics blended with the branched organopolysiloxane of the present invention have a light feel, good spreadability, and a uniform film with high water repellency can be obtained, so that a uniform film with good durability can be obtained, and it is a sunscreen with excellent storage stability at low and high temperatures.

[0027] When an ultraviolet shielding effect is desired in a cosmetic, it is preferable to incorporate an ultraviolet absorber. Since the branched organopolysiloxane of the present invention has excellent compatibility with ultraviolet absorbers, a cosmetic containing such an ultraviolet absorber is a cosmetic having a good feel in use, excellent stability over time, and cosmetic durability. The compound name may be written as the cosmetic display name, or INCI (International Nomenclature of Cosmetic Ingredients). When the cosmetic display name and INCI correspond, the English description may be omitted.

[0028] There are no particular limitations on the ultraviolet absorbing agent, so long as it is a raw material that can be normally incorporated into cosmetics. Specifically, oxybenzone-1 (display name (INCI: Benzophenone-1)), oxybenzone-2 (display name (INCI: Benzophenone-2)), oxybenzone-3 (display name (INCI: Benzophenone-3)), oxybenzone-4 (display name (INCI: Benzophenone-4)), oxybenzone-5 (display name (INCI: Benzophenone-5)), oxybenzone-6 (display name (INCI: Benzophenone-6)), oxybenzone-9 (display name (INCI: Benzophenone-9)), homosalate (INCI), octocrylene, t-butyl methoxydibenzoylmethane, ethylhexyl salicylate, diethylamino hydroxybenzoyl hexyl benzoate, polysilicone-15, dimethoxybenzylidene dioxoimidazolidine octyl propionate (display name (INCI: Ethylhexyl Dimethoxybenzylidene Dioxoimidazolidine Propionate), Terephthalylidene Dicamphor Sulfonic Acid (Inci: Terephthalylidene Dicamphor Sulfonic Acid), Ethylhexyl Triazone (Inci), Bis(trimethylsiloxy)silylisopentyl Trimethoxycinnamate (Inci: Isopentyl Trimethoxycinnamate Trisiloxane), Drometrizole Trisiloxane (Inci), Ethylhexyl Dimethyl PABA (Inci: Ethylhexyl Dimethyl PABA), Isopropyl Methoxycinnamate (Inci: Isopropyl Methoxycinnamate), Ethylhexyl Methoxycinnamate, Bisethylhexyloxyphenol Methoxyphenyl Triazine, Phenylbenzimidazole Sulfonic Acid (Inci: Phenylbenzimidazole Sulfonic Methylenebisbenzotriazolyltetramethylbutylphenol, Dimethoxycinnamate, Ethylhexanoate, Glyceryl (Display Name (INCI: Glyceryl Acid)Ethylhexanoate Dimethoxycinnamate), Glyceryl PABA (INCI), Methyl Diisopropyl Cinnamate (Display name: (INCI: Diisopropyl Methyl Cinnamate)), Cinoxate (INCI), Ethylhexyl Dimethoxybenzylidene Dioxoimidazolidine Propionate (Display name: (INCI: Ethylhexyl Dimethoxybenzylidene Dioxoimidazolidine Propionate)), etc. It is also possible to use a UVA absorber (such as diethylaminohydroxybenzoyl hexyl benzoate) in combination with a UVB absorber (such as ethylhexyl methoxycinnamate), and they can also be combined in any desired manner.

[0029] In this case, the ultraviolet absorber is preferably one or more organic ultraviolet absorbers selected from ethylhexyl methoxycinnamate (INCI: Ethylhexyl Methoxycinnamate), diethylamino hydroxybenzoyl hexyl benzoate (INCI: Diethylamino Hydroxybenzoyl Hexyl Benzoate), ethylhexyl salicylate (INCI: Ethylhexyl Salicylate), polysilicone-15 (INCI), t-butyl methoxydibenzoylmethane (INCI: Butyl Methoxydibenzoylmethane), oxybenzone (INCI: Benzophenone), methylene bisbenzotriazolyl tetramethylbutylphenol (INCI), bisethylhexyloxyphenol methoxyphenyl triazine (INCI) and octocrylene (INCI). Such organic ultraviolet absorbers are particularly preferred because they have an increased ultraviolet absorbing effect and excellent compatibility with the branched organopolysiloxane of the present invention.

[0030] The amount of the ultraviolet absorber in the cosmetic is preferably 1 to 50% by mass, and more preferably 3 to 20% by mass. EXAMPLES

[0031] The present invention will be described in detail below with reference to Synthesis Examples and Examples, but the present invention is not limited to the following Examples. Note that Synthesis Examples show methods for synthesizing the branched organopolysiloxane of the present invention, and Examples show examples in which the branched organopolysiloxane of the present invention is blended. 1 H-NMR was performed using a Brucker AvanceIII400. 29 Si-NMR was measured using an ECX-500 manufactured by JEOL. Purity is the area % of a chromatogram measured by gas chromatography. The kinematic viscosity is the value measured at 25°C using a Cannon-Fenske viscometer according to JIS Z8803:2011. The synthesis examples are examples of branched organopolysiloxanes, and the examples and comparative examples are examples of cosmetics. The blending amount listed in the product name is the blending amount in the product.

[0032] [Synthesis Example 1] 1,5-Diethyl-3-ethyldimethylsiloxy-1,1,3,5,5-pentamethyltrisiloxane In a 1L four-neck flask, add the following compound (3): [ka] 580 g of an organohydrogenpolysiloxane (100% purity) represented by the formula: and 0.6 g of a toluene solution of 0.5% by mass of chloroplatinic acid-vinylsiloxane complex were added. Ethylene gas was blown into the liquid while stirring at 40-50°C, and a hydrosilylation reaction was carried out while maintaining the temperature at 60-70°C. The reaction was monitored by gas chromatography, and the reaction was terminated when it was confirmed that the product ratio was 95% or more. Distillation under reduced pressure (oil bath temperature 90-130°C, 1-30 hPa) was carried out to obtain 630 g of a colorless, transparent liquid fraction. The obtained fraction 1 H-NMR and 29 By Si-NMR spectrum analysis, the target compound represented by the following formula (4) was obtained. [ka] It was confirmed that an organopolysiloxane having the structure shown in the formula (1,5-diethyl-3-ethyldimethylsiloxy-1,1,3,5,5-pentamethyltrisiloxane) was obtained with a purity of 100% and a yield of 83%. The kinetic viscosity was 2.5 mm 2 / s and the boiling point was 113°C / 10 hPa. 1 The H-NMR spectrum chart is shown in Figure 1. 29 The Si-NMR spectrum chart is shown in FIG.

[0033] [Synthesis Example 2] 1,5-Diethyl-3-trimethylsiloxy-1,1,3,5,5-pentamethyltrisiloxane In a 1L four-neck flask, add the following compound (5): [ka] To the mixture were added 490 g of an organohydrogenpolysiloxane (72% purity) represented by the formula: and 0.5 g of a toluene solution of 0.5% by mass of chloroplatinic acid-vinylsiloxane complex. While stirring at 40-50°C, ethylene gas was blown into the liquid, and a hydrosilylation reaction was carried out while maintaining the temperature at 60-70°C. The reaction was monitored by gas chromatography, and the reaction was terminated when it was confirmed that the product ratio was 95% or more. Distillation under reduced pressure (oil bath temperature 90-130°C, 1-30 hPa) was carried out to obtain 153 g of a colorless, transparent liquid fraction. The obtained fraction was 1 H-NMR and 29 By Si-NMR spectrum analysis, the target compound represented by the following formula (6) was obtained. [ka] It was confirmed that an organopolysiloxane having the structure shown in the formula (1,5-diethyl-3-trimethylsiloxy-1,1,3,5,5-pentamethyltrisiloxane) was obtained with a purity of 100% and a yield of 36%. The kinetic viscosity was 2.2 mm 2 / s and the boiling point was 97°C / 10 hPa.

[0034] [Compatibility test with ethylhexyl methoxycinnamate] The compatibility of the branched organopolysiloxanes obtained in Synthesis Examples 1 and 2 and other silicon compounds with ethylhexyl methoxycinnamate (organic UV absorber) was evaluated by the method described below. The evaluation results are shown in Table 1. (Evaluation method) The branched organopolysiloxanes and other silicon compounds obtained in Synthesis Examples 1 and 2, and ethylhexyl methoxycinnamate (sometimes referred to as OMC) were collected in the mass ratios shown in Table 1. The mixture was shaken and mixed at room temperature, and the state of dissolution was observed the next day. The state of dissolution is indicated by ○ for dissolution and × for separation.

[0035] [Table 1] KF-96L-1.5cs: Decamethyltetrasiloxane (manufactured by Shin-Etsu Chemical Co., Ltd.) KF-96L-2cs: Dode Methylpentasiloxane (Shin-Etsu Chemical Co., Ltd.) TMF-1.5: Tristrimethylsiloxymethylsilane (manufactured by Shin-Etsu Chemical Co., Ltd.) KF-995: Decamethylcyclopentasiloxane (Shin-Etsu Chemical Co., Ltd.) D6: Dodecamethylhexasiloxane

[0036] As shown in Table 1, it was clear that the branched organopolysiloxanes obtained in Synthesis Examples 1 and 2 of the present invention have higher compatibility with ethylhexyl methoxycinnamate than other silicon compounds.

[0037] [Compatibility and crystallization test with oily ingredients that are solid at 25℃] The branched organopolysiloxane obtained in Synthesis Example 2 and other organopolysiloxanes were evaluated for compatibility with solid oily components at 25° C. and for the effect on crystallization by the methods described below. The evaluation results are shown in Table 2.

[0038] (Evaluation method) Each oil component that is solid at 25°C, the branched organopolysiloxane obtained in Synthesis Example 2, and other organopolysiloxanes were collected in a mass ratio of 1:9, heated at 90°C for 20 minutes, and the state of dissolution was visually observed. Evaluation was based on the following criteria. Uniform dissolution:◎ Uniform dispersion:〇 Separation:×

[0039] After that, each heated mixture was placed in a jar and left to solidify at 25°C for 2 days, and the rheometer hardness of the solid was measured. The measurements were performed using a rheometer RT2002D·D (manufactured by Rheotec Corporation) with three measurements each under the following conditions: RANGE: 200g, adapter: φ3mm (rod type), sample stage speed: 5cm / min, and penetration width: 1cm. The average of the three measurements was calculated. A higher value indicates a harder material (unit: g).

[0040] [Table 2] KF-96L-1.5cs: Decamethyltetrasiloxane (manufactured by Shin-Etsu Chemical Co., Ltd.) KF-96L-2cs: Dode Methylpentasiloxane (Shin-Etsu Chemical Co., Ltd.) TMF-1.5: Tristrimethylsiloxymethylsilane (manufactured by Shin-Etsu Chemical Co., Ltd.) KF-995: Decamethylpentasiloxane (Shin-Etsu Chemical Co., Ltd.) KF-4422: Diethyloctamethyltetrasiloxane (Shin-Etsu Chemical Co., Ltd.)

[0041] As shown in Table 2, the branched organopolysiloxane of the present invention was well dissolved or uniformly dispersed in all solid oil components. In particular, when candelilla wax was used, it was found that the other silicon compounds all separated, whereas the branched organopolysiloxane of the present invention was uniformly dispersed. Also, when polyethylene was used, it was found that the compatibility was better than that of linear dimethylpolysiloxane. Furthermore, it was found that the hybrid composition could be solidified by cooling the heated composition.

[0042] It is generally known that when a hybrid composition is prepared using an oil agent that is highly compatible with solid oily components such as wax, the hardness of the composition that is cooled and solidified after heating and dissolution is low, and even if the composition is uniformly dissolved or dispersed during heating, it may be difficult to obtain a sufficient hardness after cooling to obtain a cosmetic composition that has excellent stability over time. It has been revealed that when the branched organopolysiloxane of the present invention is used, it is well dissolved or uniformly dispersed in any solid oily component, and has a higher hardness after cooling than other silicon compounds.

[0043] The present invention will be specifically explained below with reference to examples and comparative examples of cosmetic formulations containing the branched organopolysiloxanes obtained in Synthesis Examples 1 and 2 of the present invention, but the present invention is not limited to these examples. The blending amounts are shown in % (mass %) unless otherwise specified.

[0044] [Examples 1 and 2, Comparative Examples 1 to 3] W / O type sunscreen The branched organopolysiloxanes obtained in Synthesis Examples 1 and 2 were used in Examples 1 and 2, and were not used in Comparative Examples 1 to 3. W / O type sunscreens were prepared according to the following production method. The compositions of Examples 1 and 2 and Comparative Examples 1 to 3 are shown in Table 3.

[0045] [Table 3] (Note 1) Decamethylcyclopentasiloxane (manufactured by Shin-Etsu Chemical Co., Ltd.) (Note 2) Tristrimethylsiloxymethylsilane (INCI: Methyltrimethicone) (manufactured by Shin-Etsu Chemical Co., Ltd.) (Note 3) Diphenylsiloxyphenyl trimethicone (Shin-Etsu Chemical Co., Ltd.) (Note 4) A mixture of 70-80% dimethicone and 20-30% (dimethicone / (PEG-10 / 15)) crosspolymer (manufactured by Shin-Etsu Chemical Co., Ltd.) (Note 5) A mixture of 80-85% diphenylsiloxyphenyl trimethicone + 15-20% crosslinked phenyl-modified dimethylpolysiloxane (manufactured by Shin-Etsu Chemical Co., Ltd.) (Note 6) Cetyl PEG / PPG-10 / 1 Dimethicone (Shin-Etsu Chemical Co., Ltd.)

[0046] [Manufacturing method] Components 1 to 12 were stirred and mixed uniformly. Separately, components 13 to 16 were uniformly dissolved in component 17, and the mixture was gently added to the mixture of components 1 to 12 and stirred to form an emulsion. This was filled into a specified container to obtain a sunscreen.

[0047] The obtained W / O type sunscreen was subjected to a usage test by a panel of 10 women experts, who assessed (1) the feel (light feel), (2) the spreadability, (3) the uniformity of the film, and (4) the durability of the cosmetic film, based on the following criteria. The results are shown below based on the average scores obtained. In addition, (5) the condition of the cosmetic when left undisturbed at 40°C for one month, and (6) the condition of the cosmetic when left undisturbed at 5°C for one month were also observed. The evaluation results are shown in Table 4.

[0048] (Score) 5 points: very good 4 points: Good 3 points: Average 2 points: slightly poor 1 point: Defective (Evaluation Criteria) ◎: Average score is 4.5 or higher ○: Average score is between 3.5 and 4.5 points △: Average score is between 2.5 and 3.5 points ×: Average score is 1.5 points or more and less than 2.5 points ××: Average score is less than 1.5 points

[0049] [Table 4]

[0050] As is clear from Table 4, the sunscreens of Examples 1 and 2 have a light feel, good spreadability, and a uniform film with high water repellency compared to Comparative Examples 1 to 3, demonstrating that they are sunscreens that can provide a uniform film with good cosmetic film durability. It was also made clear that these sunscreens have excellent storage stability. [Industrial Applicability]

[0051] The branched organopolysiloxane of the present invention is highly volatile and highly compatible with organic compounds, and is therefore suitable as a substitute for organic solvents, oils for cosmetics, etc. Furthermore, the production method of the present invention can easily obtain a branched organopolysiloxane with high purity, and is therefore suitable for use in applications where impurities are a problem.

Claims

1. The following formula (1) 【Chemistry 1】 (In the formula, R 1 are independently alkyl groups having 1 to 3 carbon atoms; R 2 are independently alkyl groups having 2 or 3 carbon atoms; R 3 are independently an alkyl group having 1 to 3 carbon atoms. n is 1 or 2, and m is an integer of 0 to 3 when n=1, and is 0 or 1 when n=2. The bonding order of each siloxane unit is not limited to the above, and the bonding state of the siloxane units may be in a block or random form. The branched organopolysiloxane is represented by the formula:

2. 2. The branched organopolysiloxane according to claim 1, which has a boiling point at 10 hPa in the range of 87 to 119° C.

3. In the above formula (1), R 1 is a methyl group or an ethyl group, R 2 is an ethyl group, R 3 3. The branched organopolysiloxane according to claim 1, wherein is a methyl group, n is 1, and m is 0.

4. The following formula (2) 【Chemistry 2】 (In the formula, R 4 are independently a hydrogen atom or the above R 1 R 5 are independently a hydrogen atom or the above R 3 In addition, m and n are the same as those in the formula (1), the bonding order of each siloxane unit is not limited to the above, and the bonding state of the siloxane units may be in a block or random form.

2. A process for producing the branched organopolysiloxane of claim 1, comprising a hydrosilylation reaction step of reacting an organohydrogenpolysiloxane represented by the following formula: with an alkene having 2 or 3 carbon atoms.

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