More particularly, this invention relates to a water-based suspension and water-based emulsion of the aforesaid type that are very stable, impose little environmental burden, and have little effect on the human body.

[0002] Water-based suspensions of crosslinked silicone particles comprising water, crosslinked silicone particles (CSPs), and surfactant and water-based emulsions of CSP- containing oil are known (see JP-A-Sho 63-309565, JP-A-Hei 11-140191, and JP-A- 2000-281903). It has also been disclosed that the addition of such suspensions to water- based paints can impart a mat or flat appearance to the resulting paint film (see US-A- 5708057) and that their use in water-based cosmetics leads to an improved use sensation (see US-A-5871761 and US-A-5928660).

[0003] These water-based suspensions and water-based emulsions employ nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and mixtures thereof as surfactants. Nonionic surfactants are optimally used in the particular case of cosmetic applications because surfactants of this type generate an excellent dispersibility by the crosslinked silicone particles and oil containing crosslinked silicone particles.

[0004] The desire has arisen in recent years for the surfactant in these water-based suspensions and water-based emulsions to be selected so as to impose little environmental burden while at the same time providing an improved stability for the suspension or emulsion itself and an improved dispersibility in blends. For example, the C 12-C 15 alkyl polyethers, as chemical substances for which there is a risk of environmental effects, are identified as discharge-restricted designated chemical substances in the Pollutant Release and Transfer Register (PRTR) and their use is gradually being limited. In addition, the

cosmetic applications of surfactants produced from a starting material of animal fat origin (e. g. , beef tallow), and particularly the cosmetic applications of surfactants containing alkyl of animal fat origin, are being restricted pursuant to the notice of 12 December 2000 from the Director of the Pharmaceutical and Medical Safety Bureau of the Japan Ministry of Health and Welfare, entitled"Ensuring the Quality and Safety of Pharmaceutical and Medical Products, etc., Produced from Starting Materials of Bovine and Other Origins".

[0005] As a result of intensive investigations directed to solving the problems identified above, the inventors discovered that these problems could be solved by selecting the oxyethylene adducts of C16 alcohol of non-animal fat origin for the surfactant used in water-based suspensions of CSPs and water-based emulsions of oil containing CSPs.

[0006] This invention relates to a water-based suspension of crosslinked silicone particles wherein said suspension comprises (A) crosslinked silicone particles having an average particle size of 0.1 to 500 um, (B) the oxyethylene adduct of C16 alcohol of non-animal fat origin, and (C) water.

[0007] This invention also relates to a water-based emulsion of oil that contains crosslinked silicone particles wherein said emulsion comprises (A) crosslinked silicone particles having an average particle size of 0.1 to 500 jum, (E) oil, (B) the oxyethylene adduct of C16 alcohol of non-animal fat origin, and (C) water.

[0008] The inventive water-based CSP suspension will be considered in detail first.

The crosslinked silicone particles (A) are the base component of the inventive suspension.

Their average particle size should be 0.1 to 500 cm and is preferably 0. 1 to 100 Fm, more preferably 0.1 to 50 um, and particularly preferably 0.5 to 50 jum. It is difficult to produce CSPs with an average particle size below the lower limit on the aforementioned range, while the dispersibility in, for example, cosmetics and paints, undergoes a progressive decline when the average particle size exceeds the upper limit on the aforementioned range.

The shape of component (A) can be, for example, spherical, flat, or irregular, but a spherical shape is preferred for the particularly good dispersibility in cosmetics and paints afforded by this shape. In regard to its characteristics component (A) can be, for example, a hard rubber, soft rubber, or gel.

[0009] Component (A) may also contan noncrosslinkable oil. While there are no limitations on this oil, its viscosity at 25°C is preferably no greater than 100,000 mm2/s, more preferably no greater than 50,000 mm2/s, and particularly preferably no greater than 10,000 mm2/s. This oil can be exemplified by silicone oils and organic oils, and silicone oils are preferred for their excellent affinity for CSPs.

[0010] The molecular structure of the silicone oil can be, for example, straight chain, partially branched straight chain, cyclic, or branched chain; straight chain and cyclic are preferred. The silicone oil can be exemplified by trimethylsiloxy-endblocked dimethylpolysiloxanes; cyclic dimethylsiloxanes; silicone oils as afforded by substituting a portion of the methyl in the former two types of silicone oils with alkyl (e. g. , ethyl, propyl, butyl), phenyl, or 3,3, 3-trifluoropropyl; and mixtures of the preceding silicone oils.

[0011] The organic oil can be exemplified by liquid paraffin, isoparaffin, hexyl laurate, isopropyl myristate, myristyl myristate, cetyl myristate, 2-octyldodecyl myristate, isopropyl palmitate, 2-ethylhexyl palmitate, butyl stearate, decyl oleate, 2-octyldodecyl oleate, myristyl lactate, cetyl lactate, lanolin acetate, stearyl alcohol, cetostearyl alcohol, oleyl alcohol, avocado oil, almond oil, olive oil, cacao oil, jojoba oil, sesame oil, safflower oil, soy oil, camellia oil, squalane, persic oil, castor oil, cottonseed oil, coconut oil, polypropylene glycol monooleate, neopentyl glycol 2-ethylhexanoate, isostearic triglyceride, cocofatty acid triglyceride, polyoxyethylene lauryl ether, and polyoxypropylene cetyl ether.

[0012] The content of these noncrosslinkable oils in component (A) is not critical, but is preferably no greater than 80 weight% and more preferably is no greater than 50 weight%. Production of the CSPs becomes problematic when the upper limit on this range

is exceeded. Moreover, exceeding the upper limit on the given range makes it possible that a water-based emulsion of oil that contains CSPs, vide infra, will be formed.

[0013] The content of component (A) in the inventive suspension is not critical, but is preferably 25 to 80 weight% and more preferably is 40 to 80 weight%. A component (A) content below the lower limit on the given range risks placing limitations on the applications of the inventive suspension. Exceeding the upper limit on the given range causes a progressive decline in the handling characteristics and in the dispersibility in cosmetics and paints.

[0014] Component (B), the oxyethylene adduct of C16 alcohol of non-animal fat origin, is the component that distinguishes this invention. This component functions as a nonionic surfactant. Component (B) not only improves the stability of the inventive suspension itself, but also improves the dispersibility and stability when the inventive suspension is blended into another component. Component (B) also addresses the issues with regard to the environment and human body. Component (B) can be the oxyethylene adduct of C16 long-chain alcohol of synthetic or vegetable oil origin and can be specifically exemplified by the oxyethylene adducts of n-cetyl alcohol (C16) of non-animal fat origin, for example, polyoxyethylene n-cetyl ether of vegetable oil origin. These polyoxyethylene n-cetyl ethers are commercially available, for example, from Nikko Chemicals Co. , Ltd., under the product names NIKKOL BC-2, NIKKOL BC-5.5, NIKKOL BC-7, NIKKOL BC- 10TX, NIKKOL BC-15TX, NIKKOL BC-20TX, NIKKOL BC-23, NIKKOL BC-25TX, NIKKOL BC-30TX, and NIKKOL BC-40TX.

[0015] The oxyethylene adducts of branched long-chain alcohol can also be used as component (B). These can be specifically exemplified by the oxyethylene adducts of isocetyl alcohol (C16) of non-animal fat origin, for example, polyoxyethylene hexyldecyl ether of vegetable oil origin as illustrated by the following formula

in which m is 2-40. These polyoxyethylene hexyldecyl ethers are commercially available, for example, from Nikko Chemicals Co. , Ltd. , under the product names NIKKOL BH-2, NIKKOL BH-5, NIKKOL BH-7, NIKKOL BH-10, NIKKOL BH-15, NIKKOL BH-20, NIKKOL BH-25, and NIKKOL BH-30 and from Nihon Emulsion Co. , Ltd. , under the product names EMALEX 1605, EMALEX 1610, EMALEX 1615, EMALEX 1620, and EMALEX 1625.

[0016] The HLB (hydrophile-lipophile balance) in component (B) is not particularly critical, but a value of at least 10 is preferred and values of 12-18 are particularly preferred. For the purposes of this invention the HLB is the value calculated using Griffin's equation as follows. molecular weight of the polyoxyethylene moiety 100 HLB = x molecular weight of 5 component (B) A single species may be used for component (B), or component (B) can take the form of a mixture of two or more species that have different HLB values. For example, oxyethylene adduct having 2-10 moles of ethylene oxide addition can be mixed with oxyethylene adduct having 15-30 moles of ethylene oxide addition so as to adjust the average HLB to greater than or equal to 10. While the number of moles of ethylene oxide addition in component (B) is not particularly critical, values of 2-40 are preferred and values of 2-30 are particularly preferred.

[0017] The content of component (B) in the inventive suspension is not critical, but is preferably 0.001 to 20 weight% and particularly preferably is 0.01 to 10 weight%. The dispersibility in cosmetics and paints undergoes a progressive decline when the component (B) content falls below the lower limit on the given range. A component (B) content in excess of the upper limit on the given range risks placing limitations on the applications of the inventive suspension.

[0018] The water (C) is the dispersion medium for component (A) and can be, for example, pure water or ion-exchanged water.

[0019] The inventive suspension comprises at least the components (A), (B), and (C) described above, but may also contain (D) a phenoxyethanol with the general formula

as an optional component. This component (D) functions to improve the surface activity of component (B) and at the same time can induce the stable dispersion of component (A) in water even in the presence of reduced amounts of component (B). Component (D) also functions as a preservative. R in the above formula is the hydrogen atom or methyl group and preferably is the hydrogen atom. The subscript n in the above formula is an integer with a value of 1 to 10, preferably 1 to 5, and particularly preferably is 1. The purity of this component (D) is not critical, but is preferably at least 90 weight%.

[0020] The content of component (D) in the inventive suspension is not critical, but is preferably 0. 01 to 10 weight parts, more preferably 0. 01 to 1 weight part, and particularly preferably 0.1 to 1 weight part for each 100 weight parts of the total of components (A), (B), and (C). In those cases where the amount of component (B) has been reduced, the stability of the inventive suspension undergoes a progressive deterioration at a component (D) content below the lower limit on the given range. A component (D) content above the upper limit on the given range risks placing limitations on the applications of the inventive suspension.

[0021] While the procedure for blending component (D) is not particularly critical, component (D) is preferably blended with the other components after it has been preliminarily mixed with component (B). This procedure can facilitate the blending of component (B) and also enables the amount of component (B) addition to be reduced.

[0022] The inventive suspension may contain other components on an optional basis, for example, alcohols such as ethanol, isopropanol, tert-butanol, ethylene glycol, propylene glycol, and diethylene glycol; water-soluble polymers such as carboxyvinyl polymers and sodium carboxymethylcellulose ; preservatives; antibacterials; antimolds ; rust preventives; fragrances; and pigments. Various surfactants can be used, within a range that does not impair the object of this invention, in order to obtain additional improvements in

the stability when blended into other components. These surfactants can be exemplified by anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants.

A single one of these components may be used, or a combination of a plurality of these components may be employed. The blending sequence for these components is not particularly critical.

[0023] The method for preparing the inventive suspension is not critical. For example, the inventive suspension can be prepared by first adding and dispersing a crosslinkable silicone composition into an aqueous solution comprising components (B) and (C) and other optional components and thereafter crosslinking said composition. In another example, a crosslinkable silicone composition lacking its crosslinking catalyst is first added and dispersed into an aqueous solution comprising components (B) and (C) and other optional components and the composition is thereafter crosslinked by adding the catalyst. In the case of the latter method, the crosslinking catalyst is preferably added dispersed in an aqueous solution of component (B).

[0024] The crosslinkable silicone composition used to prepare the inventive suspension can be exemplified by hydrosilylation-crosslinkable silicone compositions, condensation-crosslinkable silicone compositions, organoperoxide-crosslinkable silicone compositions, and ultraviolet-crosslinkable silicone compositions. The use of hydrosilylation-crosslinkable silicone compositions and condensation-crosslinkable silicone compositions is preferred.

[0025] The hydrosilylation-crosslinkable silicone compositions under consideration can be exemplified by compositions comprising at least organopolysiloxane that contains at least two alkenyl groups in each molecule, organopolysiloxane that contains at least two silicon-bonded hydrogen atoms in each molecule, and platinum catalyst.

[0026] The condensation-crosslinkable silicone compositions under consideration can be exemplified by compositions comprising at least organopolysiloxane that contains at least two Si-bonded hydroxyl or hydrolyzable groups in each molecule, silane-type crosslinker containing at least three Si-bonded hydrolyzable groups in each molecule, and condensation catalyst. The hydrolyzable groups can be exemplified by alkoxy, oxime,

acetoxy, and aminoxy, while the condensation catalyst can be exemplified by organotin compounds and organotitanium compounds. This composition is preferably an alcohol- eliminating condensation-crosslinkable silicone composition comprising at least organopolysiloxane that contains at least two Si-bonded hydroxyl or alkoxy groups in each molecule, silane-type crosslinker that contains at least three Si-bonded alkoxy groups in each molecule, and a condensation catalyst such as an organotin compound or organotitanium compound.

[0027] The inventive water-based emulsion of oil that contains CSPs will now be considered in detail. The crosslinked silicone particles (A) which are a base component of the inventive emulsion are as described above in connection with suspensions.

[0028] The oil (E), which is also a base component of the inventive emulsion, is not particularly critical, but its viscosity at 25°C is preferably no greater than 100,000 mm2/s, more preferably no greater than 50,000 mm2/s, and particularly preferably no greater than 10,000 mm2/s. This oil can be exemplified by silicone oils and organic oils, and silicone oils are preferred for their excellent affinity for CSPs. These silicone oils and organic oils can be exemplified as above. It is preferred that component (E) be dispersed as droplets in the water and that the crosslinked silicone particles (A) be contained in these droplets. The average particle size of the droplets of component (E) is preferably 0.1 to 500, um, more preferably 0.1 to 100 pm, and even more preferably 0.1 to 50 um.

[0029] The content of component (E) is not critical and will depend on the oil absorptivity of component (A). However, the component (E) content is preferably at least 50 weight% and particularly preferably at least 60 weight% of the total weight of components (A) and (E). There is a risk when the component (E) content falls below the lower limit on the given range that the component (E) dispersed in the water will be unable to contain component (A).

[0030] The content of component (A) plus component (E) in the inventive emulsion is not critical, but is preferably within the range of 25 to 90 weight% and more preferably is 40 to 80 weight%. A component (A) plus component (E) content below the

lower limit on the given range risks placing limitations on the applications of the inventive emulsion. Exceeding the upper limit on the given range causes a progressive decline in the handling characteristics and in the dispersibility in cosmetics and paints.

[0031] Component (B) is the component that distinguishes this invention and is the same as already described above.

[0032] The content of component (B) in the inventive emulsion is not critical, but is preferably 0.001 to 20 weight% and particularly preferably is 0.01 to 10 weight%. The dispersibility in cosmetics and paints undergoes a progressive decline when the component (B) content falls below the lower limit on the given range. A component (B) content in excess of the upper limit on the given range risks placing limitations on the applications of the inventive emulsion.

[0033] The water (C) is the dispersion medium for components (A) and (E) and can be, for example, pure water or ion-exchanged water.

[0034] The inventive emulsion comprises at least the components (A), (E), (B), and (C) described above, but may also contain (D) a phenoxyethanol with the general formula as an optional component. This component (D) functions to improve the surface activity of component (B) and at the same time can induce the stable dispersion of components (A) and (E) in water even in the presence of reduced amounts of component (B). Component (D) also functions as a preservative. R and n in the preceding formula are the same as specified above. The purity of and procedure for blending this component again are the same as described above.

[0035] The content of component (D) in the inventive emulsion is not critical but is preferably 0.01 to 10 weight parts, more preferably 0.01 to 1 weight part, and particularly preferably 0.1 to 1 weight part for each 100 weight parts of the sum of components (A), (E), (B), and (C). In those cases where the amount of component (B) has been reduced,

there is a risk that the stability of the inventive emulsion will decline when the component (D) content falls below the lower limit on the given range. A component (D) content above the upper limit on the given range risks placing limitations on the applications of the inventive emulsion.

[0036] The various additives already described above can also be added and blended into the inventive emulsion as optional components.

[0037] The method for preparing the inventive emulsion is not critical. For example, the inventive emulsion can be prepared by first adding and dispersing a component (E) -containing crosslinkable silicone composition into an aqueous solution comprising components (B) and (C) and other optional components and thereafter crosslinking said composition. In another example, a component (E)-containing crosslinkable silicone composition lacking its crosslinking catalyst is first added and dispersed into an aqueous solution comprising components (B) and (C) and other optional components and the composition is thereafter crosslinked by adding the catalyst. In the case of the latter method, the crosslinking catalyst is preferably added dispersed in an aqueous solution of component (B).

[0038] The crosslinkable silicone composition used to prepare the inventive emulsion can be exemplified by hydrosilylation-crosslinkable silicone compositions, condensation-crosslinkable silicone compositions, organoperoxide-crosslinkable silicone compositions, and ultraviolet-crosslinkable silicone compositions. The use of hydrosilylation-crosslinkable silicone compositions and condensation-crosslinkable silicone compositions is preferred. These hydrosilylation-crosslinkable silicone compositions and condensation-crosslinkable silicone compositions can be exemplified by the same compositions as provided above.

[0039] The inventive water-based suspension of CSPs and water-based emulsion of oil that contains CSPs are characterized by an excellent stability and also by the fact that they impose little environmental burden and have little effect on the human body.

Moreover, the inventive suspension and emulsion, because they exhibit a good dispersibility in cosmetics and paints and because when blended into cosmetics and paints

they enable a full manifestation of the effects of the addition of CSPs, are useful as components for cosmetics and paints.

[0040] Examples The invention is described in greater detail below through illustrative examples, in which the values reported for viscosity were measured at 25°C. The polyoxyethylene hexyldecyl ether used in the examples had the formula wherein the C6H13 and C8Hl7 were both straight chain. The water-based suspensions of CSPs and water-based emulsions of oil containing CSPs were evaluated as follows.

[0041] Average particle size of the crosslinked silicone particles in the water-based suspensions The water-based suspension was submitted to measurement using a laser scattering particle size distribution analyzer (LA-500 from Horiba, Ltd. ). The median diameter (50% diameter = diameter corresponding to 50% in the cumulative distribution) obtained from this measurement is reported as the average size of the crosslinked silicone particles. The particle diameter at 90% in the cumulative distribution is reported as the 90% particle size.

Average particle size of the oil droplets in the water-based emulsions The water-based emulsion was submitted to measurement using a laser scattering particle size distribution analyzer (LA-500 from Horiba, Ltd. ). The median diameter (50% diameter = diameter corresponding to 50% in the cumulative distribution) obtained from this measurement is reported as the average size of the oil droplets. The particle diameter at 90% in the cumulative distribution is reported as the 90% particle size.

Average particle size of the crosslinked silicone particles in the water-based emulsions

The water was removed from the water-based emulsion and the resulting oil composition containing CSPs was inspected with a microscope. The average value of the particle diameter of ten CSPs was calculated.

Stability The water-based suspension or water-based emulsion was first diluted with water to give a solids concentration of 50 weight%. 150 mL of the dilution was introduced into a 225-mL mayonnaise jar and was then allowed to stand for two weeks at 50°C. The stability was evaluated by measuring the height of the water layer that had separated after this two-week period. In this case, smaller values for the height are indicative of a better stability.

[0042] Example 1 94.8 weight parts dimethylvinylsiloxy-endblocked dimethylpolysiloxane (400 mm2/s) containing 2.5 weight% of an approximately 20 mm2/s mixture of dimethylsiloxane cyclics was mixed to homogeneity with 5.2 weight parts trimethylsiloxy- endblocked dimethylsiloxane-methylhydrogensiloxane copolymer (50 mm2/s, silicon- bonded hydrogen content = 0.31 wt%, this quantity provided a value of 0.95 for the molar ratio of the silicon-bonded hydrogen to the vinyl in the dimethylpolysiloxane). To this was then added an aqueous solution of 30 weight parts pure water and 1.0 weight part polyoxyethylene hexyldecyl ether (NIKKOL BH-10 from Nikko Chemicals Co. , Ltd., ethylene oxide adduct of isocetyl alcohol of vegetable oil origin, number of moles of ethylene oxide addition = 10, HLB = 13. 4, liquid at room temperature) followed by emulsification using a colloid mill and then dilution with 30 weight parts pure water to give a water-based silicone composition emulsion.

A water-based platinum catalyst emulsion with an average particle size of 0.2 pm was prepared as follows: 1 weight part of a 1,3-divinyltetramethyldisiloxane and isopropyl alcohol mixed solution of a 1,3-divinyltetramethyldisiloxane complex of platinum was stirred to homogeneity into an aqueous solution of 27 weight parts ion-exchanged water and 0.3 weight part of the above-identified polyoxyethylene hexyldecyl ether (NIKKOL

BH-10 from Nikko Chemicals Co. , Ltd. , number of moles of ethylene oxide addition = 10, HLB = 13. 4, liquid at room temperature).

The water-based platinum catalyst emulsion was stirred to homogeneity, in an amount that provided 5 weight-ppm platinum metal referred to the silicone composition, into the water-based silicone composition emulsion prepared as described above. This was followed by holding at quiescence for one day to give a water-based suspension of crosslinked silicone particles through the hydrosilylation-induced crosslinking of the silicone composition. The average particle size of the crosslinked silicone particles in the resulting water-based suspension and the stability of the suspension were measured; the results are reported in Table 1.

[0043] Example 2 94.8 weight parts dimethylvinylsiloxy-endblocked dimethylpolysiloxane (400 mm2/s) containing 2.5 weight% of an approximately 20 mm2/s mixture of dimethylsiloxane cyclics was mixed to homogeneity with 5.2 weight parts trimethylsiloxy- endblocked dimethylsiloxane-methylhydrogensiloxane copolymer (50 mm2/s, silicon- bonded hydrogen content = 0. 31 wt%, this quantity provided a value of 0.95 for the molar ratio of the silicon-bonded hydrogen to the vinyl in the dimethylpolysiloxane). To this was then added an aqueous solution of 20 weight parts pure water and a mixture of 1 weight part polyoxyethylene n-cetyl ether (NIKKOL BC-lOTX from Nikko Chemicals Co. , Ltd., ethylene oxide adduct of cetyl alcohol of vegetable oil origin, number of moles of ethylene oxide addition = 10, HLB = 13. 5, solid at room temperature) dissolved in 1.2 weight parts phenoxyethanol with the formula (PHE-S from Yokkaichi Chemical Co. , Ltd. , purity = 92-94 weight%). Emulsification using a colloid mill and then dilution with 30 weight parts pure water gave a water-based silicone composition emulsion. A water-based platinum catalyst emulsion prepared as in Example 1 was stirred to homogeneity, in an amount that provided 5 weight-ppm platinum metal referred to the silicone composition, into the aforementioned water-based emulsion.

This was followed by holding at quiescence for one day to give a water-based suspension

of crosslinked silicone particles through the hydrosilylation-induced crosslinking of the silicone composition. The average particle size of the crosslinked silicone particles in the resulting water-based suspension and the stability of the suspension were measured; the results are reported in Table 1.

[0044] Example 3 94.8 weight parts dimethylvinylsiloyx-endblocked dimethylpolysiloxane (400 mm2/s) containing 2.5 weight% of an approxiamtely 20 mm2/s micture of dimethylsiloxane cyclics was mixed to homogeneity with 5.2 weight parts triemthylsiloxy- endblocked dimethylsiloxane-methylhydrogensil9oxane copolymer (50 mm2/s, silicon- bonded hydrogen content = 0.31 wt%, this quantity provided a value of 0.95 for the molar ratio of the silicon-bonded hydrogen to the vinyl in the dimethylpolysiloxane). To this was then added an aqueous solution of 20 weight parts pure water, 0.5 weight part polyoxyethylene (5. 5EO) n-cetyl ether (NIKKOL BC-5.5 from Nikko Chemicals Co. , Ltd., ethylene oxide adduct of cetyl alcohol of vegetable oil origin, number of moles of ethylene oxide addition = 5.5, HLB = 10.5, solid at room temperature), and 0.5 weight part polyoxyethylene (20EO) n-cetyl ether (NIKKOL BC-20TX from Nikko Chemicals Co., Ltd. , ethylene oxide adduct of cetyl alcohol of vegetable oil origin, number of moles of ethylene oxide addition = 20, HLB = 17.0, solid at room temperature) followed by emulsification using a colloid mill and then dilution with 30 weight parts pure water to give a water-based silicone composition emulsion. A water-based platinum catalyst emulsion prepared as in Example 1 was stirred to homogeneity, in an amount that provided 5 weight-ppm platinum metal referred to the silicone composition, into the aforementioned water-based emulsion. This was followed by holding at quiescence for one day to give a water-based suspension of crosslinked silicone particles through the hydrosilylation- induced crosslinking of the silicone composition. The average particle size of the crosslinked silicone particles in the resulting water-based suspension and the stability of the suspension were measured; the results are reported in Table 1.

[0045] Example 4

94.8 weight parts dimethylvinylsiloxy-endblocked dimethylpolysiloxane (400 mm2/s) containing 2.5 weight% of an approximately 20 mm2/s mixture of dimethylsiloxane cyclics was mixed to homogeneity with 5.2 weight parts trimethylsiloxy- endblocked dimethylsiloxane-methylhydrogensiloxane copolymer (50 mm2/s, silicon- bonded hydrogen content = 0.31 wt%, this quantity provided a value of 0.95 for the molar ratio of the silicon-bonded hydrogen to the vinyl in the dimethylpolysiloxane). To this was then added an aqueous solution of 20 weight parts pure water and a mixture of 0.2 weight part polyoxyethylene (10EO) n-cetyl ether (NIKKOL BC-lOTX from Nikko Chemicals Co. , Ltd., ethylene oxide adduct of cetyl alcohol of vegetable oil origin, number of moles of ethylene oxide addition = 10, HLB = 13.5, solid at room temperature) and 0.3 weight part polyoxyethylene (25EO) n-cetyl ether (NIKKOL BC-25TX from Nikko Chemicals Co. , Ltd. , ethylene oxide adduct of cetyl alcohol of vegetable oil origin, number of moles of ethylene oxide addition = 25, HLB = 18. 5, solid at room temperature) dissolved in 1.2 weight parts phenoxyethanol with the formula (PHE-S from Yokkaichi Chemical Co. , Ltd., purity = 92-94 weight%). Emulsification using a colloid mill and then dilution with 30 weight parts pure water gave a water-based silicone composition emulsion. A water-based platinum catalyst emulsion prepared as in Example 1 was stirred to homogeneity, in an amount that provided 5 weight-ppm platinum metal referred to the silicone composition, into the aforementioned water-based emulsion.

This was followed by holding at quiescence for one day to give a water-based suspension of crosslinked silicone particles through the hydrosilylation-induced crosslinking of the silicone composition. The average particle size of the crosslinked silicone particles in the resulting water-based suspension and the stability of the suspension were measured; the results are reported in Table 1.

[0046] Comparative Example 1 A water-based suspension of crosslinked silicone particles was prepared as in Example 1, but in this case using a polyoxyethylene stearyl ether (NIKKOL BS-20 from Nikko Chemicals Co. , Ltd. , ethylene oxide adduct of stearyl alcohol of vegetable oil origin,

HLB = 18. 0, number of moles of ethylene oxide addition = 20, solid at room temperature) in place of the polyoxyethylene hexyldecyl ether that was used in Example 1. The average particle size of the crosslinked silicone particles in the resulting water-based suspension and the stability of the suspension were measured; the results are reported in Table 1.

[0047] Comparative Example 2 The attempt was made to prepare a water-based suspension of crosslinked silicone particles as in Example 1 using 0.2 weight part polyoxyethylene (4EO) stearyl ether (NIKKOL BS-4 from Nikko Chemicals Co. , Ltd. , ethylene oxide adduct of stearyl alcohol of vegetable oil origin, HLB = 9. 0, number of moles of ethylene oxide addition = 4, solid at room temperature) and 0.3 weight part polyoxyethylene (20EO) stearyl ether (NIKKOL BS-20 from Nikko Chemicals Co. , Ltd. , ethylene oxide adduct of stearyl alcohol of vegetable oil origin, HLB = 18.0, number of moles of ethylene oxide addition = 20, solid at room temperature) in place of the polyoxyethylene hexyldecyl ether that was used in Example 1. However, emulsification could not be achieved in this case and a water-based suspension could not be prepared.

[0048] Table 1. Ex. 1 Ex. 2 Ex. 3 Ex. 4 Comp. Comp. Ex. 1 Ex. 2 surfactant HLB* 13.4 13.5 13.8 15.3 18 14.4 particle size of the crosslinked silicone particles average particle size (jum) 4.4 3.5 4.8 4.4 8. 5 90% particle size 7.5 5.9 8.5 7.7 21. 3 suspension stability: height of the water layer (mm) 10 6 12 10 30 * The HLB is the weighted average value when two species of surfactants were used.

[0049] Example 5 The following were mixed to homogeneity: 18. 02 weight parts dimethylvinylsiloxy-endblocked methylvinylsiloxane-dimethylsiloxane copolymer (400 mm2/s, vinyl content = 1.18 weight%), 1.98 weight parts trimethylsiloxy-endblocked dimethylsloxane-methylhydrogensiloxane copolymer (55 mm2/s, silicon-bonded hyrogen content = 0.48 weight%, this quantity provided a value of 0.95 for the molar ratio of the silicon-bonded hydrogen to the vinyl in the methylvinylsiloxane-dimethylsiloxane copolymer), and 80 weight parts trimethylsiloxy-endblocked dimethylpolysiloxane (100 mm2/s). To this was then added an aqueous solution of 20.0 parts pure water, 0.2 weight part polyoxyethylene (10EO) hexyldecyl ether (NIKKOL BH-10 from Nikko Chemicals Co. , Ltd. , ethylene oxide adduct of isocetyl alcohol of vegetable oil origin, number of moles of ethylene oxide addition = 10, HLB = 13. 4, liquid at room temperature), 0.3 weight part polyoxyethylene (25EO) hexyldecyl ether (NIKKOL BH-25TX from Nikko Chemicals Co. , Ltd. , ethylene oxide adduct of isocetyl alcohol of vegetable oil origin, number of moles of ethylene oxide addition = 25, HLB = 16.6, solid at room temperature), and 1.2 weight parts phenoxyethanol with the formula (PHE-S from Yokkaichi Chemical Co. , Ltd. , purity = 92-94 weight%). Emulsification using a colloid mill and then addition of an aqueous solution of 28 weight parts pure water and 8 weight parts ethanol gave a water-based silicone composition emulsion.

A water-based platinum catalyst emulsion with an average particle size of 0. 3 um was prepared as follows: 1 weight part of a 1,3-divinyltetramethyldisiloxane and isopropyl alcohol mixed solution of a 1,3-divinyltetramethyldisiloxane complex of platinum was stirred to homogeneity into an aqueous solution of 27 weight parts ion-exchanged water and 0.3 weight part of the aforementioned polyoxyethylene (1 OEO) hexyldecyl ether (NIKKOL BH-10 from Nikko Chemicals Co. , Ltd. , number of moles of ethylene oxide addition = 10, HLB = 13. 4, liquid at room temperature).

The water-based platinum catalyst emulsion was stirred to homogeneity, in an amount that provided 5 weight-ppm platinum metal referred to the silicone composition,

into the water-based silicone composition emulsion. This was followed by holding at quiescence for one day to give, through occurrence of the hydrosilylation reaction, a water- based emulsion of silicone oil that contained crosslinked silicone particles. The resulting water-based emulsion was submitted to measurement of its stability, the average particle size of the crosslinked silicone particles, and the average particle size of the silicone oil droplets; the results are reported in Table 2.

[0050] Example 6 The following were mixed to homogeneity: 18.02 weight parts dimethylvinylsiloxy-endblocked methylvinylsiloxane-dimethylsiloxane copolymer (400 mm2/s, vinyl content = 1. 18 weight%), 1.98 weight parts trimethylsiloxy-endblocked dimethylsiloxane-methylhydrogensiloxane copolymer (55 mm2/s, silicon-bonded hydrogen content = 0.48 weight%, this quantity provided a value of 0.95 for the molar ratio of the silicon-bonded hydrogen to the vinyl in the methylvinylsiloxane-dimethylsiloxane copolymer), and 80 weight parts trimethylsiloxy-endblocked dimethylpolysiloxane (100 mm2/s). To this was then added an aqueous solution of 20.0 weight parts pure water, 0.2 weight part polyoxyethylene (lOEO) n-cetyl ether (NIKKOL BC-lOTX from Nikko Chemicals Co. , Ltd. , ethylene oxide adduct of cetyl alcohol of vegetable oil origin, number of moles of ethylene oxide addition = 10, HLB = 13.5, solid at room temperature), 0.3 weight part polyoxyethylene (25EO) n-cetyl ether (NIKKOL BC-25TX from Nikko Chemicals Co. , Ltd. , ethylene oxide adduct of cetyl alcohol of vegetable oil origin, number of moles of ethylene oxide addition = 25, HLB = 18.5, solid at room temperature), and 1.2 weight parts phenoxyethanol with the formula (PHE-S from Yokkaichi Chemical Co. , Ltd., purity = 92-94 weight%). Emulsification using a colloid mill and then addition of an aqueous solution of 28 weight parts pure water and 8 weight parts ethanol gave a water-based silicone composition emulsion. A water- based platinum catalyst emulsion prepared as in Example 5 was stirred to homogeneity, in an amount that provided 5 weight-ppm platinum metal referred to the silicone composition,

into the water-based silicone composition emulsion. This was followed by holding at quiescence for one day to give, through occurrence of the hydrosilylation reaction, a water- based emulsion of silicone oil that contained crosslinked silicone particles. The resulting water-based emulsion was submitted to measurement of its stability, the average particle size of the crosslinked silicone particles, and the average particle size of the silicone oil droplets; the results are reported in Table 2.

[0051] Comparative Example 3 Using the procedure of Example 5, the attempt was made to prepare a water-based emulsion of silicone oil that contained crosslinked silicone particles by using 0.2 weight part polyoxyethylene (4EO) stearyl ether (NIKKOL BS-4 from Nikko Chemicals Co. , Ltd., ethylene oxide adduct of stearyl alcohol of vegetable oil origin, HLB = 9.0, number of moles of ethylene oxide addition = 4, solid at room temperature) and 0.3 weight part polyoxyethylene (20EO) stearyl ether (NIKKOL BS-20 from Nikko Chemicals Co. , Ltd., ethylene oxide adduct of stearyl alcohol of vegetable oil origin, HLB = 18. 0, number of moles of ethylene oxide addition = 20, solid at room temperature) in place of the polyoxyethylene (10EO) hexyldecyl ether and polyoxyethylene (25EO) hexyldecyl ether that were used in Example 5. However, emulsification could not be achieved in this case and a water-based emulsion could not be prepared.

[0052] Table 2. Example 5 Example 6 Comparative Example 3 surfactant HLB* 15.3 15.3 14.4 particle size of the silicone oil droplets average particle size (jus) 3.6 4. 6 - 90% particle size 6.5 8. 4 particle size of the crosslinked silicone particles average particle size (µm) 3 4 - emulsion stability: height of the water layer (mm) 2 4- * The HLB is the weighted average value when two species of surfactants were used.