Biodegradable silicone elastomer particles having hydrophilic groups at crosslinking sites, cosmetic compositions and other uses

Abstract

This invention provides a novel silicone elastomer particle with excellent biodegradability and the ability to impart superior tactile and usability to cosmetics, as well as its uses. The biodegradable silicone elastomer particle has a structure in which at least two silicon atoms within the silicone elastomer particle are cross-linked through divalent organic groups containing hydrophilic groups, and the silicone elastomer particle contains -(R₂SiO₂) m The polyorganosiloxane structure represented by - (where R is an unsubstituted or halogenated alkyl group with 1 to 20 carbon atoms, an aryl group with 6 to 22 carbon atoms, or a hydroxyl group with 6 to 22 carbon atoms, and m is a number in the range of 1 to 1000).

Description

Technical Field

[0001] This invention relates to a novel organosilicon elastomer particle possessing a structure in which silicon atoms are cross-linked through divalent organic groups containing hydrophilic groups. This structure exhibits excellent biodegradability and imparts a superior tactile and user experience to cosmetics. Because this biodegradable organosilicon elastomer particle possesses a cross-linked structure containing hydrophilic groups active for biodegradability, it is expected that in nature, through degradation reactions by microorganisms or the like, its primary particles will break down along with the generation of non-cross-linked siloxane molecules, and its behavior as a biodegradable particle is anticipated. Furthermore, this invention relates to cosmetic raw materials, cosmetic compositions, organic resin additives, and other uses comprising this biodegradable organosilicon elastomer particle. Background Technology

[0002] Organosilicon elastomer particles are obtained by curing addition-reaction-curable organosilicon compositions or condensation-reaction-curable organosilicon compositions. Although their particle size or oil absorption varies depending on the manufacturing method, they are widely used as cosmetic raw materials or stress relievers for thermoplastic resins. For example, as organosilicon particles with excellent dispersibility, high lipophilicity, and excellent storage stability, the applicant has proposed an organosilicon particle described in Patent Document 1. This organosilicon particle has a low content of hydrogen atoms bonded to silicon atoms per unit mass. It is formed by curing organosilicon particles containing alkenyl groups with 4 to 20 carbon atoms, such as hexenyl groups, using a crosslinking composition. It also contains alkylene groups with 4 to 20 carbon atoms.

[0003] On the other hand, the applicant noted an inherent problem with existing silicone elastomer particles. That is, although existing silicone elastomer particles are formed through a cross-linking reaction of organopolysiloxane raw materials based on hydrosilylation, the cross-linked structure is chemically stable. If these silicone elastomer particles were released into nature, like so-called microplastics, the possibility of them remaining in nature for at least a short period without decomposition cannot be ruled out. Therefore, to reduce the risk to the environment, there may be a potential market demand for silicone elastomer particles that can readily replace or substitute for existing silicone elastomer particles and exhibit high biodegradability. In view of this potential market demand, the applicant has filed copolymer particles as described in Patent Documents 2-7. Furthermore, Patent Documents 8 and 9 disclose silicone-based particles with expected biodegradability.

[0004] On the other hand, Patent Documents 10 and 11 propose forming silicone elastomer particles through a crosslinking reaction between polyoxyalkylene compounds and organopolysiloxane raw materials via hydrosilylation or similar processes. However, the polyoxyalkylene crosslinked silicone elastomer particles involved are prone to swelling and even deformation, making it difficult to impart sufficient rubber properties. Furthermore, individual elastomer particles cannot achieve the same hardness, elasticity (rubber properties), and resulting feel and tactile sensation as existing products. Moreover, since they lack crosslinking sites active for biodegradability, even with hydrophilic sites within the molecule, highly biodegradable silicone elastomer particles cannot be provided, nor can they offer any structural inspiration regarding biodegradability to those skilled in the art.

[0005] On the other hand, Non-Patent Documents 1-3 disclose the biodegradability of polycarbonate compounds with polyol-terminated structures. In Non-Patent Document 1, polycarbonates with aromatic groups such as phenyl groups are difficult to biodegrade, but polycarbonates composed of aliphatic groups consisting of straight-chain hydrocarbons show good biodegradability. Non-Patent Documents 2 and 3 also show the biodegradability of polycarbonates composed of aliphatic groups. There is no record or suggestion regarding free-radical polymerizable polycarbonate-modified organosilicon compounds with multiple polycarbonate structures with low polymerization degree and specific polysiloxane structures, or organosilicon-polycarbonate copolymer particles obtained by free-radical polymerization of these compounds. In particular, no specific record or suggestion is provided for biodegradable organosilicon elastomer particles with inter-silicon atom cross-linking structures formed by cross-linking agents with specific hydrophilic groups.

[0006] In addition, Non-Patent Document 4 discloses a polydimethylsiloxane (PDMS) particle with a polycaprolactone (PCL) structure, and discloses a rubber-like elastomer particle with biodegradability and elastic modulus. However, it does not provide specific descriptions or instructions for biodegradable organosilicon elastomer particles with inter-silicon crosslinking structure formed by a crosslinking agent with specific hydrophilic groups.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: International Patent Publication WO2017 / 191798

[0010] Patent Document 2: International Patent Publication WO2022 / 138346

[0011] Patent Document 3: International Patent Publication WO2023 / 120689

[0012] Patent Document 4: International Patent Publication WO2023 / 120690

[0013] Patent Document 5: International Patent Application PCT / JP2023 / 46100

[0014] Patent Document 6: International Patent Application PCT / JP2023 / 46101

[0015] Patent Document 7: International Patent Application PCT / JP2023 / 46102

[0016] Patent Document 8: International Patent Publication WO2022 / 019179

[0017] Patent Document 9: International Patent Publication WO2023 / 238840

[0018] Patent Document 10: Japanese Patent Application Publication No. 2001-163732

[0019] Patent Document 11: Patent Publication No. 111393679 of the People's Republic of China

[0020] Non-patent literature

[0021] Patent Document 1: Biodegradation of Aliphatic and Aromatic Polycarbonates (Trishul Artham, Mukesh Doble et al., Macro-Molecular Bioscience, 2007)

[0022] Non-patent document 2: Phylogenetic Affiliation of Soil Bacteria That DegradeAliphatic Polyesters Available Commercially as Biodegradable Plastics (Tetsushi Suyama et al., Applied and Environmental Microbiology, 1998)

[0023] Non-patent literature 3: Bacterial isolates degrading aliphatic polycarbonates (Tetsushi Suyama et al., FEMS Microbiology Letters, 1998)

[0024] Non-patent literature 4: PCL-PDMS-PCL Copolymer-Based Microspheres MediateCardiovascular Differentiation from Embryonic Stem Cells (Liqing Song et al., TISSUE ENGINEERING: Part C, Vol. 23, No. 10, 2017) Attached Figure Description

[0025] Figure 1 The results of the enzymatic hydrolysis test (test time - degradation rate %) of the organosilicon elastomer particles in the examples and comparative examples are shown. Summary of the Invention

[0026] The problem that the invention aims to solve

[0027] The present invention was made to solve the above-mentioned problems and provides a biodegradable silicone elastomer particle. When the biodegradable silicone elastomer particle is formulated into cosmetic compositions, etc., it can achieve the same or better tactile and user experience as existing silicone elastomer particles, and has a structure that is active in biodegradability.

[0028] Furthermore, an object of the present invention is to provide cosmetic raw materials, organic resin additives, and other uses with excellent user experience by using the copolymer particles. Additionally, an object of the present invention is to provide a cosmetic composition containing the copolymer particles and possessing excellent user experience.

[0029] Furthermore, the present invention aims to provide a copolymer particle, the synthetic material thereof, and the use thereof, which, in addition to having properties equivalent to or greater than those of existing silicone elastomer particles, is also expected to be biodegradable, thereby reducing potential risks to the Earth's environment, enabling continuous and stable use in industry, and, as an environmentally friendly biodegradable material, can attract demanders and general consumers who are concerned about the impact on the Earth's environment.

[0030] Solution for solving the problem

[0031] To address the aforementioned issues, the inventors conducted in-depth research and discovered that biodegradable organosilicon elastomer particles can solve these problems, thus completing this invention. The biodegradable organosilicon elastomer particles have a structure in which at least two silicon atoms within the organosilicon elastomer particles are cross-linked through divalent organic groups containing hydrophilic groups, and the organosilicon elastomer particles contain a structure composed of…

[0032] -(R2SiO) m -

[0033] (In the formula, R is an unsubstituted or halogen-substituted alkyl group with 1 to 20 carbon atoms, an aryl group with 6 to 22 carbon atoms, or a hydroxyl group with 1 to 20 carbon atoms, and m is a number in the range of 1 to 1000.)

[0034] The structure of the polyorganosiloxane is represented.

[0035] Similarly, the inventors discovered that the above-mentioned problems can be solved by cosmetic raw materials, organic resin additives, cosmetics or organic resins containing the biodegradable organosilicon elastomer particles, thereby completing the present invention.

[0036] The effects of the invention

[0037] When the biodegradable silicone elastomer particles of this invention are formulated into cosmetic compositions, they can achieve a tactile and user experience equivalent to or better than that of conventional silicone elastomer particles. Furthermore, by using the biodegradable silicone elastomer particles of this invention, cosmetic ingredients, organic resin additives, and other applications containing these silicone elastomer particles can be provided. Additionally, cosmetic compositions containing the biodegradable silicone elastomer particles of this invention can provide cosmetics with superior user experience.

[0038] The biodegradable organosilicon elastomer particles of this invention have a cross-linked structure within their elastomer particles, formed by polyorganosiloxane chains and divalent organic groups containing hydrophilic groups. These divalent organic groups with hydrophilic groups are designed to possess the following properties: in a biodegradable environment, the cross-linked structure formed between silicon atoms within the copolymer particles at least partially breaks down, and the primary particles break down with the generation of non-cross-linked polyorganosiloxanes. Therefore, the elastomer particles of this invention are biodegradable, reducing the risk to the environment and, as an environmentally friendly material that can be used with considerable safety, attracting those concerned about environmental impact and general consumers. Detailed Implementation

[0039] In this specification, the term "(meth)acrylic acid" means "acrylic acid or methacrylic acid," and when expressed as "(meth)acrylic acid modified," it means that the modifying group can be one or both of an acrylic acid modifying group and a methacrylic acid modifying group. Similarly, the term "(meth)acryloyloxy" means "methacryloyloxy or acryloyloxy," and "organic group containing (meth)acryloyloxy" means that it can be one or both of an organic group containing methacryloyloxy and an organic group containing acryloyloxy.

[0040] [Organosilicon elastomer particles]

[0041] The following describes in detail the use of the biodegradable organosilicon elastomer particles of the present invention, particularly their use as cosmetic ingredients, their manufacturing method, and cosmetic compositions and organic resins (including coatings / coatings) containing these.

[0042] [(A) Crosslinking agents with intramolecular hydrophilic groups]

[0043] The organosilicon elastomer particles of the present invention are characterized by having a cross-linked structure through divalent organic groups containing hydrophilic groups. Here, the divalent organic groups containing hydrophilic groups are active in biodegradability, imparting to the organosilicon elastomer particles the property that, in a biodegradable environment, the cross-linked structure formed between silicon atoms within the copolymer particles at least partially breaks.

[0044] (A) Preferably derived from:

[0045] (A1) The two ends of the molecular chain are composed of R Alk R2SiO (where R is the formula) Alk An organic group containing a carbon-carbon double bond, where R is an unsubstituted or halogenated alkyl group (1-20 carbon atoms), an aryl group (6-22 carbon atoms), or a hydroxyl group (representing a hydrosilylated reactive silyl-terminated crosslinking agent containing a hydrophilic group), and...

[0046] (A2) A crosslinking agent having at least two free radical polymerizable functional groups within its molecule and containing hydrophilic groups within its molecule.

[0047] The structure of at least one crosslinking agent in the process. It should be noted that when crosslinking organohydrogen polysiloxanes with polyether compounds that have unsaturated bonds only at the ends, sufficient biodegradability cannot be achieved, and in addition, it is sometimes impossible to obtain organosilicon elastomer particles with rubber-like properties.

[0048] The aforementioned crosslinking structure is preferably formed through a crosslinking reaction selected from free radical polymerization and hydrosilylation, and preferably has the following structure: at least two silicon atoms within the organosilicon elastomer particles are preferably crosslinked through one or more reactions selected from the free radical polymerization reaction involving component (A) and the hydrosilylation reaction of silicon atoms bonded to hydrogen atoms. It should be noted that component (A) is sometimes reactive to both free radical polymerization and hydrosilylation reaction of silicon atoms bonded to hydrogen atoms; in this case, it can be introduced into the organosilicon elastomer particles through either or both reactions, without particular limitation.

[0049] The (A) component, used as a crosslinking agent, can be hydrosilylated, and preferably has R at both ends of the (A1) molecular chain. AlkR2SiO represents a hydrosilylated reactive silyl-terminated crosslinking agent containing a hydrophilic group within its molecule. By using hydrophilic compounds with hydrosilylated reactive silyl groups at the ends, the rubber properties and biodegradability of the obtained organosilicon elastomer particles can sometimes be further improved.

[0050] In the formula, R Alk It is an organic group containing a carbon-carbon double bond, and is selected from -C(=O)-R. 1 -CR 2 =CH2 represents a reactive group with a (meth)acrylic acid terminal group and an alkenyl terminal group having 2 to 20 carbon atoms. Here, R 1 The chemical bond between CH and C (=O) or a divalent organic group with 0 to 20 carbon atoms is preferred, either a simple chemical bond like "-C(=O)-CH=" or an alkylene group with 1 to 20 carbon atoms represented by CmH2m, such as "-C(=O)-CmH2m-CH=" (where m is a number in the range of 1 to 20). (It should be noted that in R...) 1 In the case of a chemical bond between CH and C (=O), m is 0. Additionally, R... 2 For hydrogen atoms or methyl groups, respectively provide acrylic acid modified groups, methacrylic acid modified groups, or alkenyl groups.

[0051] R is an unsubstituted or halogenated alkyl group with 1 to 20 carbon atoms, an aryl group with 6 to 22 carbon atoms, or a hydroxyl group. Industrially, R is preferably methyl or phenyl, each independently.

[0052] The crosslinking agent as component (A1) is a crosslinking agent containing a hydrophilic group within its molecule. This hydrophilic group is particularly preferably a polyether structure, especially a polyoxyethylene-polyoxypropylene block copolymer structure (hereinafter sometimes referred to as "Pluronic(R) structure"). The crosslinking agent as component (A1) incorporating these structures may further have a polyester structure or a polycaprolactone structure.

[0053] As such a component (A1), examples can be shown from...

[0054] [Chemical Formula 1]

[0055]

[0056] This refers to a modified polycaprolactone compound having an intramolecular polyoxyethylene-polyoxypropylene block copolymer structure. Here, m and n are preferably positive numbers, and m+n is in the range of 2 to 100, more preferably 2 to 10, and even more preferably 2 to 8. Additionally, a is the number of ethyleneoxy (EO) units, and b is the number of propyleneoxy (PO) units; preferably a and b are positive numbers, and a+b is in the range of 2 to 100, more preferably 4 to 50, and even more preferably 6 to 30. It should be noted that, in the formula, one or both of the vinyl groups bonded to the molecular chain ends of silicon atoms can be processed according to the aforementioned R... Alk The organic groups other than vinyl groups containing carbon-carbon double bonds are substituted.

[0057] Component (A) as a crosslinking agent can be free radical polymerizable, and can be a crosslinking agent having at least two free radical polymerizable functional groups within the molecule and containing hydrophilic groups within the molecule. Such component (A2) contains hydroxyl (OH) groups or polyether structures that impart hydrophilicity to the crosslinking portion, preferably having two or more hydroxyl (OH) groups, or having a polyether structure rich in hydrophilicity. More specifically, it can be one or more crosslinking agents selected from sorbitan fatty acid esters or polyoxyalkylene sorbitan fatty acid esters having at least two free radical polymerizable functional groups within the molecule of (a2-1), and crosslinking agents containing at least two free radical polymerizable functional groups and polyether structures within the molecule of (a2-2), and preferably.

[0058] There are no particular restrictions on the functional groups of free radical polymerization, and they are related to R. Alk Similarly, organic groups containing carbon-carbon double bonds are preferred, and are selected from -C(=O)-R. 1 -CR 2 =CH2 represents the reactive group in the (meth)acrylate terminal group and the alkenyl terminal group with 2 to 20 carbon atoms (R in the formula). 1 and R 2 (For the same basis as above).

[0059] The sorbitan fatty acid ester or polyoxyalkylene sorbitan fatty acid ester, as component (A2), has at least two free radical polymerizable functional groups within its molecule, and is preferably a crosslinking agent selected from sorbitan laurate, sorbitan stearate, sorbitan oleate, and polyoxyethylene sorbitan oleate. As an example, a sorbitan fatty acid ester having two (meth)acrylate terminal groups within its molecule can be exemplified. In the formula, R′ can be an alkyl group (lauryl, stearyl, oleylene, etc.) with 8 to 22 carbon atoms. Such sorbitan fatty acid esters or polyoxyalkylene sorbitan fatty acid esters are hydrophilic due to the presence of multiple hydroxyl groups (OH) within their molecules, thus improving the biodegradability of the organosilicon elastomer particles obtained as the crosslinking agent in this invention.

[0060] [Chemical Formula 2]

[0061]

[0062] The crosslinking agent, which is a component of (A2) and contains at least two free radical polymerizable functional groups and a polyether structure, is preferably a crosslinking agent having a polyester structure or a polycarbonate structure, and may also have a polycaprolactone structure. The polyether structure in the crosslinking agent, which is a component of (A2), is particularly preferably a polyoxyethylene-polyoxypropylene block copolymer structure (“Pluronic(R) structure”). When the polyether structure in component (A2) is composed of ethyleneoxy (EO) units and propyleneoxy (PO) units, it is represented by (EO)a(PO)b, preferably with a and b each being positive numbers, and a+b being in the range of 2 to 100, preferably 4 to 80, and more preferably 6 to 70.

[0063] [Cross-linking reactive organosilicon composition]

[0064] The organosilicon elastomer particles involved in this invention are preferably organosilicon elastomer particles obtained by crosslinking reactive organosilicon emulsion particles in water. The crosslinking reactive organosilicon emulsion particles are obtained by emulsifying a crosslinking reactive organosilicon composition in water, which is capable of crosslinking through one or more reactions selected from free radical polymerization and hydrosilylation of silicon atoms to hydrogen atoms. The crosslinking reactive organosilicon composition comprises at least:

[0065] A crosslinking agent containing a hydrophilic group within the molecule of component (A) above;

[0066] (B) At least one reactive organopolysiloxane selected from components (b1) and (b2) below:

[0067] (b1) Organohydrogen polysiloxanes having at least three silicon atoms bonded to hydrogen atoms within their molecules, and

[0068] (b2) An organopolysiloxane having at least three organic groups selected from those containing methacryloyloxy and at least one organic group containing (meth)acryloyloxy; and

[0069] (C) A curing agent selected from (c1) hydrosilylation catalyst and (c2) free radical polymerization initiator.

[0070] [Free radical polymerization type organosilicon elastomer particles]

[0071] The product is characterized by being obtained by free radical polymerization of an organopolysiloxane having three or more functional groups with silicon atoms bonded to silicon atoms, such as organic groups containing (meth)acryloyloxy groups, in the presence of a free radical polymerization initiator, with the component (A2), and having at least two silicon-silicon pairs within the organosilicon elastomer particles having a cross-linked structure formed by the free radical polymerization reaction of the functional groups in component (A) that are bonded to silicon atoms.

[0072] [Hydroxysilane-reactive organosilicon elastomer particles]

[0073] The product is characterized by being obtained by hydrosilylating an organopolysiloxane (=organohydropolysiloxane) having three or more silicon atoms bonded to hydrogen atoms in the molecule with the (A1) component in the presence of a hydrosilylating catalyst, and having at least two silicon-silicon atoms in the organosilicon elastomer particles with a cross-linked structure formed by the hydrosilylating reaction (addition reaction) between the hydrosilylating reactive silane in the (A1) component and the silicon atoms bonded to hydrogen atoms.

[0074] The organosilicon elastomer particles of the present invention further have the following composition:

[0075] -(R2SiO) m -

[0076] (In the formula, R is an unsubstituted or halogen-substituted alkyl group with 1 to 20 carbon atoms, an aryl group with 6 to 22 carbon atoms, or a hydroxyl group with 1 to 20 carbon atoms, and m is a number in the range of 1 to 1000.)

[0077] The structure represents a polyorganosiloxane (linear polysiloxane structure). This imparts suitable hardness and flexibility to the organosilicon elastomer particles.

[0078] In industrial applications, R is preferably methyl or phenyl, and m is preferably a number in the range of 10 to 800, more preferably a number in the range of 20 to 750.

[0079] [(B) Component]

[0080] Component (B) is a component that introduces the above-mentioned polyorganosiloxane structure into organosilicon elastomer particles by crosslinking with component (A) through one or more reactions selected from free radical polymerization and hydrosilylation of silicon atoms to bond hydrogen atoms.

[0081] (b1) is an organopolysiloxane component that is cross-linked by component (A) through a hydrosilylation reaction, characterized in that it has at least three silicon atoms bonded to hydrogen atoms in the molecule, and there is no particular limitation on the bonding position of its hydrogen atoms in the molecule.

[0082] Besides hydrogen atoms, the organic groups bonded to silicon atoms in component (b1) can be alkyl groups such as methyl, ethyl, propyl, butyl, and octyl, with methyl being preferred. Furthermore, the molecular structure of the organohydrogen polysiloxane as component (b1) can be any one of linear, branched, and branched cyclic structures, or a combination of one or more of these. It should be noted that the number of silicon-bonded hydrogen atoms in one molecule is the average of all molecules.

[0083] In particular, when component (b1) is a linear organopolysiloxane (organohydrogen polysiloxane), when the organosilicone elastomer particles involved in this invention are placed in a biodegradable environment, they easily decompose into non-crosslinked and linear organopolysiloxanes when the organosilicone elastomer particles break due to the rupture of the crosslinked structure, which has the advantage of easily reducing environmental burden and environmental risk.

[0084] The viscosity of component (b1) at 25°C is 1 to 1,000 mPa·s, preferably 5 to 500 mPa·s. If the viscosity of component (b1) at 25°C is less than 1 mPa·s, component (b1) is prone to volatilization from the crosslinking composition containing it; if it exceeds 1,000 mPa·s, the curing time of the crosslinking composition containing such component (a2) will be longer, or it may sometimes be the cause of poor curing. Such component (a2) is not particularly limited, and examples include, for instance, dimethylsiloxy-terminated dimethylsiloxane / methylhydrosiloxane copolymers, dimethylhydrosiloxy-terminated dimethylpolysiloxanes, dimethylsiloxy-terminated methylhydropolysiloxanes, cyclic methylhydropolysiloxanes, and cyclic methylhydrosiloxane / dimethylsiloxane copolymers.

[0085] Here, the molar ratio (=reaction ratio in the hydrosilylation reaction) of the carbon-carbon double bond (Alk) contained in component (A1) and the hydrogen atom content (H) of silicon atom bonded to component (b1), the H / Alk value, is preferably in the range of 0.7 to 1.2. The lower limit of the above-mentioned H / Alk is preferably 0.80 or more, 0.85 or more, 0.90 or more, or 0.95 or more, and the upper limit is 1.15 or less, more preferably 1.10 or less or 1.05 or less. If the upper limit of H / Alk exceeds the above value, unreacted silicon atom bonded to hydrogen atom is likely to remain after the reaction; conversely, if the upper limit of H / Alk is less than the above value, unreacted component (B) and its (meth)acrylate terminal groups are likely to remain after the reaction. These are curing reactive groups, and therefore, when they remain in large quantities in the particles, they can sometimes cause cross-linking reactions to occur between the particles over time. Regarding the resulting silicone elastomer particles containing oil, they can sometimes lead to poor aggregation and dispersion, and consequently, the generation of flammable hydrogen gas over time in the presence of residual reactive hydrogen atoms. Particularly preferred is that when the H / Alk value is between 0.9 and 1.1, especially close to 1.0, the curing reactive groups are completely consumed and the cross-linking reaction ends, effectively suppressing the long-term aggregation between particles.

[0086] Since component (b2) forms a cross-linked structure through a free radical reaction with component (A), it is necessary to have at least three organic groups containing (meth)acryloyloxy groups on average within the molecule. If the molecule has only two or fewer organic groups containing (meth)acryloyloxy groups on average, a sufficient cross-linked structure cannot be formed, and practical organosilicon elastomer particles are sometimes unattainable.

[0087] More specifically, an organic group containing (meth)acryloyloxy is a (meth)acryloyloxy group bonded to a silicon atom by a divalent organic group, exemplified by:

[0088] -R 2 -OC(=O)-C(R 3 )=CH2

[0089] {where R is the formula} 2 It is an alkylene group having 1 to 20 carbon atoms or (CH2). p -Si(CH3)2-O-Si(CH3)2-(CH2) q The binary linker shown (where p and q are numbers in the range of 1 to 20), R 3 It can be a hydrogen atom or a methyl group.

[0090] One or more functional groups are shown.

[0091] In the formula, R is used as 2Industrially, alkylene groups can be alkylenes with 2 to 10 carbon atoms, such as propylene, butylene, and hexylene. Additionally, (CH2) p -Si(CH3)2-O-Si(CH3)2-(CH2) q The divalent linker shown is a divalent linker with a siloxane converter structure. Industrially, examples can be shown where p and q are each independently numbered 3 to 6.

[0092] Preferably, component (b2) is a linear organopolysiloxane as shown in the following structural formula.

[0093] [Chemical Formula 3]

[0094]

[0095] In equation (1), R 11 Each of the following is independently an alkyl group (e.g., methyl, etc.) with 1 to 20 carbon atoms, an aryl group (e.g., phenyl, etc.) with 6 to 22 carbon atoms, or a hydroxyl group, either unsubstituted or halogen-substituted, with methyl or phenyl being preferred industrially. a The organic group containing (meth)acryloyloxy is described above, and is particularly preferred to be (meth)acryloyloxy with silicon atoms bonded via the aforementioned alkylene group or a divalent linker having a siloxane converter structure. R is independently derived from R 11 or R a The base is represented by m, where m is a number greater than or equal to 1, and n is a number greater than or equal to 1. Here, because component (a) contains at least three elements of R within the molecule... a The expression indicates an organic group containing (meth)acryloyloxy group; therefore, when m=1, R must always be R. a That is, the linear organopolysiloxane shown in the above structural formula has R at any one of the single-terminal and side-chain sites, the side-chain-only site, or the two-terminal and side-chain sites of its siloxane molecule. a The organic group containing (meth)acryloyloxy group shown can be an organopolysiloxane containing at least three organic groups containing (meth)acryloyloxy group within the molecule, and is preferred.

[0096] m+n is the degree of polymerization of the linear organopolysiloxane molecules other than the terminal siloxane structure. From the viewpoint of workability, emulsification, and the ability to break down into fine linear siloxane molecules during biodegradation, m+n is preferably in the range of 10 to 800, more preferably in the range of 20 to 600, and particularly preferably in the range of 30 to 500. Furthermore, it is particularly preferred that the viscosity of component (a) is in the range of 20 to 10,000 mPa·s at 25°C.

[0097] Component (C) is a curing agent, selected from (c1) a free radical polymerization initiator and (c2) a hydrosilylation reaction catalyst, depending on the choice of component (A) and the reaction system.

[0098] Component (c1) is a free radical initiator, which promotes the free radical polymerization or free radical copolymerization of components (a1) and (B) mentioned above. As a free radical initiator, existing and well-known compounds commonly used in free radical polymerization can be used. Specifically, examples include: azo compounds such as 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile), and 2,2'-azobis(2,4-dimethylpentanonitrile); organic peroxides such as benzoyl peroxide, lauroyl peroxide, tert-butyl peroxide, tert-butyl peroxide-2-ethylhexanoate, and tert-hexyl peroxide-2-ethylhexanoate; and persulfates such as potassium persulfate, sodium persulfate, and ammonium persulfate. This free radical initiator can be used alone or in combination with two or more.

[0099] The amount of the free radical initiator as component (c1) is preferably in the range of 0.1 to 5 parts by mass relative to the total of 100 parts by mass of components (a1) and (B) mentioned above. In particular, when component (c1) is a water-soluble persulfate such as potassium persulfate, it has the advantage of being extremely easy to add and react when cross-linking reactive organosilicon emulsion particles, which are obtained by emulsifying the cross-linking reactive organosilicon composition obtained by free radical polymerization in water, are subjected to cross-linking reaction in water. Furthermore, at the end of the free radical polymerization reaction, for the purpose of neutralizing the solution with the cessation of the reaction and pH adjustment, it is particularly preferable to add aminomethylpropylene glycol or the like in the range of 0.1 to 5 parts by mass.

[0100] The timing of adding component (c1) to the crosslinking composition can be selected according to the method of forming the silicone elastomer particles. It can be added to the composition in advance, or it can be added to either component (a1) or component (B) from different spray lines and mixed in the spray. The silicone elastomer particles in this invention are preferably formed by emulsification in water to form an aqueous suspension. Component (c1) can also be added to the crosslinking reactive silicone composition in advance, or an emulsion containing component (c1) can be added to the water separately.

[0101] During the polymerization reaction of the above-mentioned crosslinking reactive organosilicon composition, a chain transfer agent may be added arbitrarily. Specifically, examples of such chain transfer agents include: 2-mercaptoethanol, butyl mercaptan, n-dodecyl mercaptan, 3-mercaptopropyltrimethoxysilane, polydimethylsiloxane having a mercaptopropyl group, and other thiol compounds; and halides such as dichloromethane, chloroform, carbon tetrachloride, butyl bromide, and 3-chloropropyltrimethoxysilane.

[0102] (c2) is a hydrosilylation catalyst, which is a catalyst that promotes the addition reaction (hydrosilylation) of carbon-carbon double bonds contained in the alkenyl terminal groups present in the above-mentioned crosslinking composition and hydrogen atoms bonded to silicon atoms. Preferred hydrosilylation catalysts are hydrosilylation catalysts containing platinum group metals. Specifically, examples include: chloroplatinic acid, alcohol-modified chloroplatinic acid, olefin complexes of chloroplatinic acid, complexes of chloroplatinic acid and ketones, complexes of chloroplatinic acid and vinylsiloxanes, platinum tetrachloride, platinum fine powder, substances formed by supporting solid platinum on an alumina or silica support, platinum black, platinum olefin complexes, platinum alkenylsiloxane complexes, platinum carbonyl complexes, and platinum group catalysts containing methyl methacrylate resin, polycarbonate resin, polystyrene resin, silicone resin, and other thermoplastic organic resin powders. In particular, platinum-based siloxane complexes such as the complexes of chloroplatinic acid and divinyltetramethyldisiloxane, the complexes of chloroplatinic acid and tetramethyltetravinylcyclotetrasiloxane, the platinum-divinyltetramethyldisiloxane complex, and the platinum-tetramethyltetravinylcyclotetrasiloxane complex are preferred. It should be noted that non-platinum metal catalysts such as iron, ruthenium, and iron / cobalt can be used as catalysts to promote the hydrosilylation reaction.

[0103] The amount of component (c2) added to the crosslinking composition is only the amount of catalyst. Generally, relative to the total mass of the crosslinking composition, the amount of platinum group metal contained in component (c2) is preferably in the range of 1 to 1,000 ppm, and more preferably in the range of 5 to 500 ppm. It should be noted that the amount of platinum metal in organosilicon elastomer particles can also be reduced by the method proposed by the inventors in Japanese Patent Application Publication No. 2014-122316.

[0104] The timing of adding component (c2) to the crosslinking composition can be selected according to the method of forming the silicone elastomer particles. It can be added to the composition in advance, or it can be added to either component (A) or component (B) from different spray lines and mixed in the spray. The oil-containing silicone elastomer particles of the present invention are preferably formed via an aqueous suspension through emulsification in water. Component (c2) can also be added to the crosslinking reactive silicone composition in advance, or an emulsion containing component (c2) can be added to the water separately.

[0105] The aforementioned crosslinking reactive organosilicon compositions may also contain curing retarders, such as hydrosilylation inhibitors. Examples of curing retarders include acetylene compounds, enyne compounds, organonitrogen compounds, organophosphorus compounds, and oxime compounds. Specific compounds include acetylene alcohols such as 2-methyl-3-butyn-2-ol, 3,5-dimethyl-1-hexyn-3-ol, 3-methyl-1-pentyn-3-ol, 2-phenyl-3-butyn-2-ol, and 1-ethynyl-1-cyclohexanol (ETCH); 3-methyl-3-trimethylsilaneoxy-1-butyne, 3-methyl-3-trimethylsilaneoxy-1-pentyne, 3,5-dimethyl-3-trimethylsilaneoxy-1-hexyne, 3-methyl-3-... -Penten-1-yne and 3,5-dimethyl-3-hexen-1-yne, etc., are alkenyne compounds; 1-ethynyl-1-trimethylsiloxycyclohexane, bis(2,2-dimethyl-3-butynoxy)dimethylsilane, methyl(tris(1,1-dimethyl-2-propynoxy))silane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane and 1,3,5,7-tetramethyl-1,3,5,7-tetrahexenylcyclotetrasiloxane, etc., are alkenyl siloxanes. The amount added is in the range of 0.001 to 5 parts by mass per 100 parts by mass of component (a), but can be appropriately designed according to the type of curing delay agent used, the characteristics of the hydrosilylation reaction catalyst used, and the amount used.

[0106] From the viewpoint of preventing unexpected side reactions, the above-mentioned crosslinking reactive organosilicon composition may contain one or more polymerization inhibitors. For example, it may contain one or more inhibitors selected from hindered phenolic polymerization inhibitors, hydroquinone polymerization inhibitors, and catechol polymerization inhibitors. The amount used can be appropriately selected, but the total concentration of the polymerization inhibitors relative to the sum of the above components (A) to (C) is preferably 50 ppm by mass or less, more preferably 30 ppm by mass or less.

[0107] The crosslinking reactive organosilicon composition may contain components other than those mentioned above, without impairing the technical effects of the present invention. For example, it may contain: aliphatic hydrocarbons such as n-hexane, cyclohexane, and n-heptane; aromatic hydrocarbons such as toluene, xylene, and mesitylene; ethers such as tetrahydrofuran and dipropyl ether; organic solvents such as ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; antioxidants such as phenols, quinones, amines, phosphorus compounds, phosphites, sulfur compounds, or thioethers; light stabilizers such as triazoles or benzophenone; flame retardants such as phosphate esters, halogens, phosphorus compounds, or antimony compounds; one or more antistatic agents composed of cationic surfactants, anionic surfactants, or nonionic surfactants; dyes; pigments, etc.

[0108] The organosilicon elastomer particles of the present invention may also optionally have (i) a structure in which part or all of their surface is covered by one or more selected from organopolysiloxane resins, silica and other organosilicon elastomer particles; (ii) a mesoporous structure; (iii) a structure containing an oil that is liquid at 40°C; and (iv) a structure cross-linked by silane alkylene groups having 2 to 20 carbon atoms. Any components that impart these structures may also be used in combination.

[0109] [Hardness of silicone elastomers]

[0110] Although the hardness of silicone elastomer particles cannot be directly measured, it can be indirectly measured by curing the cross-linked silicone composition used to form the silicone elastomer particles. Specifically, the cross-linked reactive silicone composition can be cured into a sheet in a non-emulsified state in water, and the hardness of the silicone elastomer sheet can be measured using a JIS A hardness tester as specified in JIS K6301. The hardness of the silicone elastomer involved in this invention varies depending on the type of cross-linked silicone composition, the amount of component (a) / (b), and the cross-linking density, but is preferably in the range of 10 to 80. Furthermore, the preferred hardness is as described above.

[0111] [Formation and Manufacturing Method of Organosilicon Elastomer Particles]

[0112] The organosilicon elastomer particles involved in this invention can be described by a method including the following steps: in the presence of a curing agent (C), curing cross-linked reactive organosilicon emulsified particles formed by emulsifying a cross-linked organosilicon composition used to form the above-mentioned organosilicon elastomer particles in water to obtain spherical organosilicon elastomer particles.

[0113] Crosslinked silicone compositions used to form silicone elastomer particles can be uniformly mixed using mechanical forces such as mixers.

[0114] In this method, silicone elastomer particles can be obtained by emulsifying and curing the above-mentioned crosslinked silicone composition in an aqueous solution of a surfactant. Furthermore, the particle size can be easily adjusted by changing the emulsion particle size. Examples of surfactants include water-soluble polymers such as nonionic, anionic, cationic, betaine, and polyvinyl alcohol. The particle size of the obtained silicone elastomer particles varies depending on the type and content of the surfactant. To prepare silicone elastomer particles with small particle sizes, the amount of surfactant added is preferably in the range of 0.5 to 50 parts by weight relative to 100 parts by weight of the crosslinked silicone composition.

[0115] To ensure that the above-mentioned crosslinked organosilicon composition is uniformly dispersed in water in the form of crosslinked reactive organosilicon emulsion particles, an emulsifier is preferably used. Examples of such emulsifiers include: homogenizers, paddle mixers, Henschel mixers, homogenizers, colloid mills, propeller agitators, homogenizers, inline continuous emulsifiers, ultrasonic emulsifiers, and vacuum mixers.

[0116] Next, by heating or placing the aqueous dispersion of crosslinked reactive organosilicon emulsion particles prepared by the above method at room temperature, the crosslinked reactive organosilicon emulsion particles in the aqueous dispersion are solidified, thereby preparing an aqueous dispersion of organosilicon elastomer particles. When heating the aqueous dispersion, from the viewpoint of hydrosilylation reactivity or free radical polymerization reactivity, the heating temperature is preferably below 100°C, and particularly preferably 10–95°C. Furthermore, as a method for heating the aqueous dispersion containing the crosslinked reactive organosilicon emulsion particles, examples include: directly heating the aqueous dispersion, and adding the aqueous dispersion to hot water. The liquid crosslinked reactive organosilicon emulsion particles, through this crosslinking reaction, solidify in water, forming an aqueous dispersion of organosilicon elastomer particles.

[0117] The resulting silicone elastomer particles of the present invention can be directly used as an aqueous dispersion (aqueous suspension). In particular, they can be used in cosmetic ingredients, etc., in the form of this aqueous suspension, and are preferred. When an aqueous solution is used as a dispersion medium in cosmetics (e.g., hair cosmetics), sometimes by formulating it in the form of an aqueous dispersion containing the silicone elastomer particles of the present invention, the silicone elastomer particles can be easily and uniformly dispersed, achieving the desired performance and user experience.

[0118] Preferably, the silicone elastomer particles involved in this invention can be separated by removing water from the aqueous dispersion of silicone elastomer particles. Methods for removing water from the aqueous dispersion include, for example, drying using a vacuum dryer, a hot air circulating oven, or a spray dryer. It should be noted that the heating / drying temperature of the spray dryer needs to be appropriately set based on the heat resistance, crosslinking temperature, etc., of the silicone elastomer particles. It should also be noted that, to prevent secondary agglomeration of the obtained particles, the temperature of the silicone elastomer particles is preferably controlled below their glass transition temperature. The silicone elastomer particles thus obtained can be recovered using a cyclone separator, bag filter, etc. It should be noted that, as a pretreatment for this operation, the dispersion can be concentrated using methods such as heating dehydration, filtration separation, centrifugation, and decantation; the dispersion can also be washed with water if necessary.

[0119] As needed, the silicone elastomer particles of the present invention can be surface-treated, which can sometimes further improve the aggregation inhibition effect of the silicone elastomer particles of the present invention. Furthermore, surface treatment can also be performed using other known hydrophilic or hydrophobic treatment agents. Optionally, as described above, the obtained silicone elastomer particles can be further coated with part or all of their surface with inorganic fine particles such as silica, silicone resin, etc. Additionally, as needed, the obtained silicone elastomer particles can be mechanically crushed or pulverized, or classified using known techniques.

[0120] Furthermore, the silicone elastomer particles obtained through this manufacturing process, especially when used as cosmetic raw materials, can sometimes further improve the appearance, spreadability, and feel of cosmetics, and the particles obtained by this manufacturing method tend to better address the problems of the present invention. Thus, one of the preferred methods for achieving the technical effects of the present invention can be specified and appropriately defined by the manufacturing process.

[0121] The average primary particle size of the silicone elastomer particles involved in this invention is not particularly limited, but they impart a smooth feel and comfortable use to cosmetics without causing undesirable appearance. From the viewpoint of ensuring the stability of the particles in storage and formulation as a cosmetic ingredient, the average primary particle size, as determined by laser diffraction scattering, is preferably in the range of 0.5–20 μm, more preferably in the range of 0.5–15 μm. It should be noted that the particle size of the silicone elastomer particles can be controlled according to the crushing / grading process of the cross-linked reactive silicone emulsion particles and the resulting silicone elastomer particles.

[0122] The shapes of the organosilicon elastomer particles involved in this invention include, for example, spherical, perfectly spherical, elliptical, and irregular shapes, with spherical and perfectly spherical shapes being particularly preferred. In the form of an aqueous suspension described later, spherical organosilicon elastomer particles can be easily obtained by drying using a vacuum dryer, a hot air circulating oven, or a spray dryer.

[0123] Furthermore, in this invention, when the cross-linking reactive silicone composition used to form silicone elastomer particles is cured into a sheet, the hardness is preferably measured using a JIS A hardness tester as specified in JIS K6301, preferably in the range of 10 to 80. If the JIS-A hardness of the rubber sheet measured after curing the cross-linking reactive silicone composition into a sheet is within the range of this range, the cohesion of the obtained silicone elastomer particles is sufficiently suppressed, making it easy to produce particles with good fluidity, dispersibility, dryness, smoothness, and softness. Furthermore, by selecting the aforementioned JIS-A hardness, the usability, feel, and workability when formulated in cosmetics can be designed or predicted to some extent. In addition, the stress relief properties when formulated in organic resins can be improved. When using the silicone elastomer particles according to this invention as stress relievers in cosmetic raw materials or organic resins, silicone elastomer particles with a JIS-A hardness in the range of 30 to 80, particularly 50 to 80, are especially preferred.

[0124] Optionally, the silicone elastomer particles of the present invention may have a structure in which part or all of their surface is coated with one or more selected from organopolysiloxane resins, silica, and other silicone elastomer particles. This coating can sometimes lead to further reductions in cohesion, control of oil absorption, and improvement in tactile feel.

[0125] Optionally, the organosilicon elastomer particles of the present invention can be mesoporous structures with micropores.

[0126] Optionally, the silicone elastomer particles of the present invention may contain an oil that is liquid at 40°C. This oil can be readily contained within the silicone elastomer particles by emulsification together with the crosslinking reactive silicone composition described later. By containing this oil, further reduction in cohesion, control of oil absorption, and improvement in tactile feel can be expected.

[0127] [Cosmetic ingredients and cosmetic compositions]

[0128] The organosilicon elastomer particles of the present invention can be used as cosmetic raw materials. When formulated into cosmetic compositions, they are soft and have a superior effect on improving the feel and usability of cosmetics. They also exhibit significantly superior workability, storage stability, and stability when formulated into a system as cosmetic raw materials.

[0129] In particular, compared with known silicone particles, the silicone elastomer particles of the present invention offer superior usability and tactile feel, greater freedom in formulation design, and when formulated into cosmetics, they absorb oily ingredients over time without thickening or changes in texture. When applied to skin or hair, they suppress greasiness and stickiness, imparting smooth spreadability and a soft or moisturizing feel, and improving skin integration, thus providing excellent usability. Furthermore, compared with other powders or existing silicone elastomer particles, when the silicone elastomer particles of the present invention are used in combination with UV protection ingredients, their UV protection effect can be improved without compromising the feel and usability of the cosmetic.

[0130] Furthermore, the organosilicon elastomer particles of the present invention possess the following properties: they have properties equivalent to or higher than those of existing known organosilicon elastomer particles, while being active in biodegradability. In a biodegradable environment, the cross-linked structure formed between silicon atoms within the organosilicon elastomer particles at least partially cracks, and the primary particles of the organosilicon elastomer particles break down with the generation of non-cross-linked polyorganosiloxanes. Therefore, they are materials with low risk to the Earth's environment and low environmental impact. Furthermore, they can replace existing known organosilicon elastomer particles and have extremely excellent versatility.

[0131] Cosmetic compositions containing the organosilicon elastomer particles of the present invention are not particularly limited in type, but examples include: cleansing cosmetics such as soaps, shower gels, and facial cleansers; basic cosmetics such as lotions, creams / lotions, and face masks; base makeup cosmetics such as face powder and foundation; eye makeup cosmetics such as lipsticks, blushes, eyeshadows, eyeliners, and mascaras; color cosmetics such as nail polish; hair cosmetics such as shampoos, conditioners, hair styling lotions, hair growth agents, hair conditioning agents, and hair dyes; aromatic cosmetics such as perfumes and colognes; toothpaste; bath products; and special cosmetics such as depilatory agents, shaving lotions, antiperspirants / deodorants, and sunscreens. Furthermore, examples of dosage forms for these cosmetic compositions include: aqueous liquids, oily liquids, lotions, creams, foams, semi-solids, solids, and powders. These cosmetic compositions can also be used by spraying.

[0132] In these cosmetic compositions, the content of the aforementioned silicone elastomer particles is preferably in the range of 0.5% to 99.0% by mass, and particularly preferably in the range of 1.0% to 95% by mass. This is because if the content of the aforementioned silicone elastomer particles exceeds the upper limit of the above range, the cosmetic effect will be lost; conversely, if it is less than the lower limit of the above range, it will be difficult to improve the user experience and other aspects of the cosmetic composition.

[0133] For cosmetic compositions (especially formulation examples) containing organosilicon particles (such as organosilicon rubber powder) or organosilicon composite particles proposed in Patent Document 1 (Japanese Patent Application Publication No. 07-316014), Patent Document 2 (International Patent Publication No. WO2017 / 191798), Patent Document 3 (Japanese Patent Application Publication No. 02-243612), Japanese Patent Application Publication No. 2011-105663, Japanese Patent Application Publication No. 2011-168634, Japanese Patent Application Publication No. 2011-102354, and Japanese Patent Application Publication No. 2014-122316, the organosilicon elastomer particles of the present invention can replace some or all of these organosilicon particles, and can sometimes further improve the user experience and production efficiency of the cosmetic compositions proposed in these patent documents. It should be noted that the silicone elastomer particles of the present invention are not limited to the examples described above as examples of cosmetic compositions containing adaptable silicone particles (such as silicone rubber powder) or silicone composite particles. Formulations can be designed to replace part or all of the silicone particles in commercially available cosmetics with the silicone elastomer particles of the present invention through general technical solutions for those skilled in the art.

[0134] Furthermore, the organosilicon elastomer particles of the present invention can replace and apply some or all of the organosilicon particles in the cosmetic compositions and formulations disclosed in the aforementioned patent documents, and such uses are included within the scope of the present invention. As an example, the silicone elastomer particles of the present invention are selected in the same manner and amount range as those disclosed in Patent Document 2 (International Patent Publication WO2017 / 191798), and can be used in combination with any of the following: cosmetic media (aqueous or oily media), oily media (including oils and volatile oils), water, colorants, pigments, UV-protective ingredients, alcohols, water-soluble polymers, film-forming agents, oils, oil-soluble gelling agents, organically modified clay minerals, surfactants, resins, salts, moisturizers, preservatives, antibacterial agents, antioxidants, pH adjusters, chelating agents, cooling agents, anti-inflammatory agents, skin-beautifying ingredients (whitening agents, cell activators, skin roughness improvers, blood circulation promoters, skin astringents, and anti-seborrheic agents, etc.), vitamins, amino acids, nucleic acids, hormones, inclusion complexes, physiologically active substances, pharmaceutical active ingredients, fragrances, etc., and preferably.

[0135] In particular, the silicone elastomer particles of the present invention have equal or better usability, tactile feel, workability, storage stability, dispersibility, and high oil absorption properties compared with existing known silicone particles, silicone composite particles coated with silsesquioxane, and silicone particles containing oil. Specifically, in…

[0136] (1) Cosmetic compositions and formulations containing oily media (oily cosmetic raw materials) such as oils;

[0137] (2) Cosmetic compositions and formulations containing lipophilic anti-UV ingredients (such as octyl paramethoxycinnamate, etc.);

[0138] (3) In cosmetic compositions and formulations containing inorganic powders such as colorants or pigments,

[0139] It can achieve a particularly suitable appearance and feel. These specific formulations are described in more detail in the following examples.

[0140] In addition, the silicone elastomer particles of the present invention can be easily designed into aqueous dispersions, thus offering excellent freedom of formulation design and formulation stability even in aqueous cosmetic compositions and formulations, enabling a comfortable user experience. These specific formulations are described in more detail in the following examples.

[0141] Regarding the manufacture of cosmetics according to the present invention, they can be easily manufactured by simply and uniformly mixing the cosmetic raw materials of the present invention as described above with other cosmetic raw materials. As a mixing method, various mixing and kneading apparatuses commonly used in the manufacture of cosmetics can be used. Examples of such apparatuses include, for example: homogenizers, paddle mixers, Henschel mixers, homogeneous dispersers, colloid mixers, propeller agitators, homogenizers, inline continuous emulsifiers, ultrasonic emulsifiers, and vacuum kneaders.

[0142] [Organic resin additives, as well as organic resins, coatings, and coating agents]

[0143] Because the silicone elastomer particles of the present invention possess the aforementioned properties, they are also very useful as additives for organic resins. Specifically, the silicone elastomer particles of the present invention exhibit excellent uniform dispersion of organic resins and desired stress-relieving properties, and are not prone to aggregation even during long-term storage, thus demonstrating significantly superior workability and storage stability. Furthermore, the components, coatings, or coating films cured with organic resins incorporating these silicone elastomer particles exhibit improved flexibility (including the flexibility of the coating itself), durability, and adhesion / follow-the-substrate properties, particularly excellent flexibility and thermal shock resistance, making them extremely useful as high-functionality organic resins, coatings, or coating agents for electronic materials.

[0144] [Organic resin]

[0145] As an organic resin comprising the silicone elastomer particles of the present invention, examples of curable organic resin compositions or thermoplastic resins are preferably provided. Among these, the curable resin is suitable for electronic materials such as semiconductor substrates. More specifically, examples of curable organic resin compositions include: phenolic resins, formaldehyde resins, xylene resins, xylene-formaldehyde resins, ketone-formaldehyde resins, furan resins, urea resins, imide resins, melamine resins, alkyd resins, unsaturated polyester resins, aniline resins, sulfone-amide resins, silicone resins, epoxy resins, copolymers of these resins, and combinations of two or more of these curable resins. In particular, as a curable resin, at least one selected from the group consisting of epoxy resins, phenolic resins, imide resins, and silicone resins is preferred. As the epoxy resin, any compound containing glycidyl groups or alicyclic epoxy groups is acceptable. Examples include: o-cresol phenolic varnish epoxy resin, phenolic phenolic varnish epoxy resin, biphenyl type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene type epoxy resin, anthracene type epoxy resin, naphthol aralkyl type epoxy resin, polyvinylphenolic type epoxy resin, diphenylmethane type epoxy resin, and diphenyl... The phenolic resins include: sulfone-type epoxy resins, triphenol alkane-type epoxy resins, cresol-naphthol co-condensation epoxy resins, biphenyl vinyl-type epoxy resins, fluorene-type epoxy resins, succinate-type epoxy resins, spirocoumarone-type epoxy resins, norbornene-type epoxy resins, terpene-type epoxy resins, phenol cyclohexane-type epoxy resins, halogenated epoxy resins, epoxy resins containing imide groups, epoxy resins containing maleic anhydride groups, allyl-modified epoxy resins, and organosilicon-modified epoxy resins. Examples of phenolic resins include: polyvinylphenol type, phenolic varnish type, naphthol type, terpene type, phenol dicyclopentadiene type, phenol aralkyl type, naphthol aralkyl type, triphenol alkane type, dicyclopentadiene type, cresol / naphthol co-condensation type, and xylene / naphthol co-condensation type. Furthermore, examples of silicone resins include epoxy-modified silicone resins, which are obtained by reacting epoxy resin with silanol groups or alkoxy groups bonded to silicon atoms in a silicone resin. Examples of curing mechanisms for such curable resins include thermosetting, high-energy ray curing (such as ultraviolet light or radiation), moisture curing, condensation reaction curing, and addition reaction curing. Additionally, the properties of such curable resins at 25°C are not limited; they can be either liquid or a solid that softens upon heating.

[0146] In the organic resin containing the organosilicon elastomer particles of the present invention, curing agents, curing accelerators, fillers, photosensitizers, higher fatty acid metal salts, ester waxes, plasticizers, etc., can be formulated as other arbitrary components. Examples of curing agents include: organic acids such as carboxylic acids and sulfonic acids and their anhydrides; organic hydroxyl compounds; organosilicon compounds having silanol groups, alkoxy groups, or halogen groups; primary or secondary amino compounds, and combinations of two or more of these may also be used. Examples of curing accelerators include: tertiary amine compounds, organometallic compounds such as aluminum or zirconium; organophosphorus compounds such as phosphine; other heterocyclic amine compounds, boron compounds, organoammonium salts, organosulfonium salts, organic peroxides, and catalysts for hydrosilylation. Examples of fillers include: fibrous fillers such as glass fiber, asbestos, alumina fiber, ceramic fiber composed of alumina and silica, boron fiber, zirconium oxide fiber, silicon carbide fiber, metal fiber, polyester fiber, aramid fiber, nylon fiber, phenolic fiber, and natural animal and plant fibers; and powder fillers such as fused silica, precipitated silica, fumed silica, calcined silica, zinc oxide, calcined clay, carbon black, glass beads, alumina, talc, calcium carbonate, clay, aluminum hydroxide, barium sulfate, titanium dioxide, aluminum nitride, silicon carbide, magnesium oxide, beryllium oxide, kaolin, mica, and zirconium oxide. Combinations of two or more of these fillers are also possible. In the case of epoxy resins, curing agents containing amines are particularly preferred.

[0147] The silicone elastomer particles of the present invention can be used as additives in thermoplastic resins other than those mentioned above, and can also be used as modifiers of physical properties such as surface lubricants or stress relievers, or modifiers of optical properties such as light scattering agents. There are no particular limitations on the type of thermoplastic resin; it can be a polymer selected from at least one of the following groups: polycarbonate resins, polyester resins, polyether resins, polylactic acid resins, polyethylene, polypropylene, ethylene-propylene copolymers, polyolefin resins, polystyrene resins, styrene copolymers, fluorinated polymers such as tetrafluoroethylene, polyvinyl ethers, and cellulose polymers, or a composite resin composed of these. For the silicone resin-coated silicone elastomer particles of the present invention, they can be uniformly dispersed in these thermoplastic resins (including masterbatches) using a mixing device such as a biaxial / single-axial extruder or a kneader, and can be molded into desired shapes such as films for use.

[0148] The amount of silicone elastomer particles added according to the present invention can be reasonably selected according to the desired physical properties of the organic resin. However, in general, it is in the range of 0.1 to 30 parts by mass relative to 100 parts by mass of the organic resin, or even 0.5 to 10 parts by mass. This is because when the amount of particles added is less than the lower limit mentioned above, the stress relief properties of the resin and the like may become insufficient, and there is a tendency for the flexibility and thermal shock resistance of the resulting cured organic resin to decrease, especially the thermal shock resistance after moisture absorption. On the other hand, when the amount of the particles added exceeds the upper limit mentioned above, the formulated organic resin or coating / coating agent may thicken, reducing workability. In addition, there is a tendency for the mechanical properties of the resulting cured organic resin to decrease.

[0149] Furthermore, the silicone elastomer particles of the present invention exhibit excellent stress-relieving properties when formulated into organic resins. Therefore, they can be formulated into epoxy resins for printed circuit boards to form prepregs. Furthermore, copper foils for printed circuit boards with a resin layer containing filler particles can be formed, so that one side of the copper foil has a resin layer containing the silicone elastomer particles of the present invention, thereby realizing its use in copper clad laminates (CCLs).

[0150] [Paints, coating agents]

[0151] Examples of coatings / coating agents containing the silicone elastomer particles of the present invention include: room temperature curing type, room temperature drying type, and heat curing type. In addition, examples of coatings / coating agents based on their properties include: water-based, oil-based, and powder-based. Furthermore, examples of coatings based on the resin of the carrier include: polyurethane resin coatings, butyraldehyde resin coatings, long-oil phthalic acid resin coatings, alkyd resin coatings, amino alkyd resin coatings composed of amino resins and alkyd resins, epoxy resin coatings, acrylic resin coatings, phenolic resin coatings, silicone-modified epoxy resin coatings, silicone-modified polyester resin coatings, and silicone resin coatings.

[0152] The amount of silicone elastomer particles added according to the desired physical properties of the coating / coating agent is rationally selected. However, in order to uniformly impart a soft matte finish to the resulting coating film, it is preferably in the range of 0.1 to 150 parts by weight relative to 100 parts by weight of the solid content of the coating, more preferably in the range of 0.1 to 100 parts by weight, and particularly preferably in the range of 0.1 to 50 parts by weight and 0.1 to 20 parts by weight. When the amount of particles added is less than the above-mentioned lower limit, the properties of the coating film, such as matte finish, adhesion, and stress relief characteristics, may be insufficient. If the amount of particles added exceeds the above-mentioned upper limit, the formulated organic resin or coating / coating agent may thicken, resulting in reduced workability.

[0153] The coatings / coating agents containing the organosilicon elastomer particles of the present invention may also contain: alcohols such as methanol and ethanol; ketones such as methyl ethyl ketone and methyl isobutyl ketone; esters such as ethyl acetate, butyl acetate, and acetic acid solvents; amides such as N,N-dimethylformamide; olefins such as hexane, heptane, and octane; organic solvents such as toluene and xylene; and known inorganic fillers, organic fillers, curing accelerators, silane coupling agents, carbon black, pigments, dyes, antioxidants, thickeners composed of polymer compounds, flame retardants, and weather-resistant agents such as reinforcing silica.

[0154] [As an environmentally friendly material]

[0155] As described above, the silicone elastomer particles of the present invention differ from existing non-biodegradable thermoplastic resin particles and silicone particle materials. In a biodegradable environment, the following biodegradable properties are expected: at least a portion of the cross-linked structure formed between silicon atoms within the silicone elastomer particles will crack, and the primary particles of the silicone elastomer particles will break down with the generation of non-cross-linked polysiloxanes. Therefore, in addition to being used as an "environmentally friendly" cosmetic and industrial raw material with low environmental burden and risk in response to restrictions such as microplastics, it is also expected to be promoted as a biodegradable "environmentally friendly" raw material to those who value the impact on the global environment and to general consumers.

[0156] Example

[0157] The biodegradable organosilicon elastomer particles and their manufacturing method of the present invention will be described in detail through examples and comparative examples. However, the present invention is not limited to these examples. The viscosity values ​​in the examples are values ​​at 25°C. Furthermore, the characteristics of each organosilicon particle were measured as follows. It should be noted that, unless otherwise specified in the examples, organosilicon particles refer to the general term for particles composed of cured organosilicon (cured organosilicon particles), excluding emulsions.

[0158] [Average primary particle size of emulsion particles]

[0159] The emulsions before the addition of the free radical polymerization initiator and before the addition of the hydrosilylation catalyst were measured using a laser diffraction particle size analyzer (Beckman Coulter LS-230). The median diameter (the particle size corresponding to 50% of the cumulative distribution and the 50% particle size) was set as the average particle size.

[0160] [Average secondary particle size of organosilicon particles (powder)]

[0161] Ethanol was used as the dispersion medium, and the particle size of the cured silicone particles was measured using a laser diffraction particle size analyzer (Malvern Panalytical Mastersizer 3000). The median diameter (the particle size equivalent to 50% of the cumulative distribution, D90, μm) and arithmetic dispersion (representing the degree of dispersion of the particle size distribution, SD, μm2) of the cured silicone particles in ethanol were obtained. The sample was dispersed in a 300 mL cup using a stirring blade and an ultrasonic vibrator to disperse 1 g of cured silicone particles and 100 mL of ethanol.

[0162] [Synthetic Example 1: Alkenyl-Modified Polycaprolactone Compound No. 1]

[0163] A four-necked separable flask was filled with 35.12 parts by weight of Pluronic L-31 (manufactured by ADEKA Co., Ltd., a glycol-type polyoxyethylene-polyoxypropylene copolymer, molecular weight: approximately 1100), 49.70 parts by weight of chloroform, and 0.22 parts by weight of triazabicyclodecene. 14.58 parts by weight of ε-caprolactone were added dropwise while N2 was bubbled through the flask. The mixture was stirred at room temperature for 4 hours. After the reaction, 0.38 parts by weight of benzoic acid were added. After standing overnight, the chloroform was removed by heating under reduced pressure while bubbling with N2, yielding a transparent polymer. 83.21 parts by weight of the obtained polymer and 16.79 parts by weight of vinylsilazane were added. The mixture was heated to 50°C while bubbling with N2, and 0.02 parts by weight of trifluoromethanesulfonic acid were added. The reaction was carried out for 4 hours. After filtration, byproducts were removed while bubbling with N2, yielding a transparent polymer. Analysis by H-NMR and Si-NMR revealed a peak originating from vinyl silaneoxy groups in the polymer, yielding a polycaprolactone (alkenyl-modified EOPO polycaprolactone compound No. 1) with the following structure and terminal modification to vinyl silaneoxy groups.

[0164] [Chemical Formula 4]

[0165]

[0166] (In the formula, m+n=4.0, a+b=18)

[0167] [Example 1: Organosilicon elastomer particles No. 1 (hydrosilylation reaction type)]

[0168] A linear organohydrogen polysiloxane (viscosity 55 mm² / s) and alkenyl-modified polycaprolactone compound No. 1 were uniformly mixed at room temperature at a mass ratio of 15:85. Next, the composition was dispersed in an aqueous solution at 25°C consisting of 0.5 parts by mass of polyoxyethylene alkyl (C12-14) ether and 30 parts by mass of pure water. The mixture was further emulsified uniformly using a colloid mill and diluted with 526 parts by mass of pure water to prepare an emulsion. Then, an isopropanol solution of chloroplatinic acid (in this composition, the amount of platinum metal is 10 ppm by mass) and the polyoxyethylene alkyl (C12-14) ether in pure water were added to the emulsion and stirred. The emulsion was then allowed to stand at 50°C for 4 hours to prepare a uniform aqueous suspension of elastomer particles. The aqueous suspension was then filtered, and the residue was dried in an oven at 50°C for 5 hours to obtain organosilicon elastomer particles No. 1. The average primary and secondary particle sizes of the obtained organosilicon elastomer particles were 0.95 μm and 30.2 μm, respectively.

[0169] [Synthesis Example 2: Methacrylic Acid Modified Organosilicon Polymer]

[0170] In a four-necked separable flask, 91.03 parts by weight of octamethylcyclosiloxane, 0.01 parts by weight of MEHQ (hydroquinone monomethyl ether, polymerization inhibitor), and 6.54 parts by weight of 3-methacryloyloxypropylmethyldimethoxysilane were charged. The mixture was heated while stirring at 200 rpm and introducing 2% O2 / N2. At 50°C, 0.05 parts by weight of trifluoromethanesulfonic acid and 1.52 parts by weight of water were added. After reacting at 55°C for 1 hour, the liquid temperature was raised to 70°C. The pressure was further reduced to 100 mmHg and reacted for approximately 1 hour to remove the byproduct methanol. Then, 0.85 parts by weight of hexamethyldisiloxane and a trace amount of water were added, and the reaction was continued for 3 hours. After the reaction, ammonia gas was bubbled in to neutralize the trifluoromethanesulfonic acid, and the resulting salt was removed by filtration with diatomaceous earth. The filtrate was then subjected to reduced pressure treatment at 150°C for 3 hours to remove volatile components. C and Si-NMR analysis revealed a methacrylic acid-modified organosilicon polymer with (a1-1)dimethylsiloxane unit 214, methacrylic acid-introduced siloxane unit 5, and a viscosity of 472 mPas.

[0171] [Chemical Formula 5]

[0172]

[0173] (where m=5, n=214) represents the methacrylic acid-modified organosilicon polymer (viscosity at 25°C is 472 mPas).

[0174] [Synthesis Example 3: Acrylic acid-modified cross-linked sorbitan anhydride monolaurate]

[0175] 35.37 parts by weight of sorbitan monolaurate and 45.18 parts by weight of chloroform were added to a four-necked separable flask. While purging with nitrogen, the mixture was stirred at room temperature, and 9.81 parts by weight of adipic acid chloride was added dropwise to bring the temperature below 30°C. After reacting for 5 hours at room temperature, 9.63 parts by weight of potassium carbonate were added, and the reaction was continued for 1 hour. Excess potassium carbonate was removed by filtration. The resulting solution was heated to 70°C. The pressure was further reduced to 100 mmHg, and chloroform was removed over approximately 1 hour. Then, the pressure was reduced to 5 mmHg, and chloroform was removed at 70°C for 2 hours. 33.94 parts by weight of the resulting cross-linked sorbitan monolaurate, 44.66 parts by weight of chloroform, 0.05 parts by weight of MEHQ (hydroquinone monomethyl ether, polymerization inhibitor), and 10.63 parts by weight of potassium carbonate were then added to a four-necked separable flask. While stirring at room temperature and passing N2 containing 2% O2, 10.71 parts by weight of acryloyl chloride were added dropwise at a temperature not exceeding 30°C, and the reaction was carried out at room temperature for 5 hours. Water was added until the liquid was neutral on pH paper. The mixture was heated to 70°C, and the pressure was reduced to 100 mmHg to remove chloroform for about 1 hour. Then, the pressure was reduced to 5 mmHg, and the chloroform was removed at 70°C for 2 hours. Analysis by H-NMR and C-NMR revealed that the polymer, which is a sorbitan anhydride laurate crosslinked with adipic acid chloride and modified with acrylic acid, was a (meth)acrylic acid modified sorbitan anhydride laurate compound.

[0176] [Chemical Formula 6]

[0177]

[0178] (R′ stands for lauryl base)

[0179] [Example 2: Organosilicon elastomer particles No. 2 (free radical polymerization type)]

[0180] The methacrylic acid-modified organosilicon polymer and the (meth)acrylic acid-modified polysorbate laurate compound were uniformly mixed at room temperature in a mass ratio of 17.2:82.8. The composition was then dispersed in a 25°C aqueous solution consisting of 0.27 parts by mass of Gohsenol EG-05C, 0.53 parts by mass of Gohsenol EG-18P, and 46 parts by mass of pure water. The mixture was further emulsified uniformly using a colloid mill, and then diluted with 526 parts by mass of pure water to prepare an emulsion. The emulsion was heated in a 1L flask to 70°C, and then 0.5g of potassium persulfate (manufactured by Sigma-Aldrich) dissolved in 9.5g of water was added dropwise over 1 minute. The emulsion was stirred at 70°C for 3 hours, and then at 80°C for 2 hours to carry out free radical polymerization, preparing a uniform aqueous suspension of organosilicon rubber particles. The aqueous suspension was then filtered and washed with 200ml of ethanol and 100ml of acetone. The residue was dried in an oven at 70°C for 5 hours to obtain silicone elastomer particles No. 3. The average primary and secondary particle sizes of the obtained silicone elastomer particles were 2.84 μm and 318 μm, respectively.

[0181] [Synthesis Example 4: Acrylic Acid Modified Polycaprolactone Compound]

[0182] In a four-necked separable flask, 42.79 parts by weight of Pluronic L-64 (manufactured by ADEKA Co., Ltd., glycol-type polyoxyethylene-polyoxypropylene copolymer, molecular weight: approximately 2900), 49.86 parts by weight of chloroform, and 0.10 parts by weight of triazabicyclodecene were added. 7.07 parts by weight of ε-caprolactone were added dropwise while N2 was bubbled through the flask. The mixture was stirred at room temperature for 4 hours. After the reaction, 0.18 parts by weight of benzoic acid were added. After standing overnight, the chloroform was removed by heating under reduced pressure while bubbling with N2 to obtain a transparent polymer. 44.53 parts by weight of the obtained polymer, 0.02 parts by weight of MEHQ (hydroquinone monomethyl ether, polymerization inhibitor), and 3.62 parts by weight of potassium carbonate were added to a four-necked separable flask and stirred at room temperature. 3.65 parts by weight of acryloyl chloride were added dropwise at a temperature not exceeding 30°C, and the reaction was allowed to proceed for 8 hours. After standing overnight, the reaction was carried out again at room temperature for 8 hours. Add a small amount of water until the solution is neutral on pH paper. Add a small amount of sodium sulfate and filter. Heat the resulting filtrate to 70°C, reduce the pressure to 100 mmHg, and remove chloroform for about 1 hour. Then, reduce the pressure to 5 mmHg and remove chloroform at 70°C for 2 hours. Analysis by ¹H-NMR and C-NMR revealed that the polymer was end-modified with acrylate groups to form polycaprolactone ((meth)acrylic acid modified polycaprolactone compound).

[0183] [Chemical Formula 7]

[0184]

[0185] (In the formula, m+n=4.0, a+b=43~45)

[0186] [Example 3: Organosilicon elastomer particles No. 3 (free radical polymerization type)]

[0187] The methacrylic acid-modified organosilicon polymer and (meth)acrylic acid-modified polycaprolactone compound NO.4 were uniformly mixed at room temperature in a mass ratio of 16.9:83.1. The composition was then dispersed in a 25°C aqueous solution consisting of 0.27 parts by mass of Gohsenol EG-05C, 0.53 parts by mass of Gohsenol EG-18P, and 46 parts by mass of pure water. The mixture was further emulsified uniformly using a colloid mill, and then diluted with 526 parts by mass of pure water to prepare an emulsion. The emulsion was heated in a 1L flask to 70°C, and then 0.5g of potassium persulfate (manufactured by Sigma-Aldrich) dissolved in 9.5g of water was added dropwise over 1 minute. The emulsion was stirred at 70°C for 3 hours, and then at 80°C for 2 hours to carry out free radical polymerization, preparing a uniform aqueous suspension of organosilicon rubber particles. The aqueous suspension was then filtered and washed with 200ml of ethanol and 100ml of acetone. The residue was dried in an oven at 70°C for 5 hours to obtain silicone elastomer particles No. 4. The average primary and secondary particle sizes of the obtained silicone elastomer particles were 15.24 μm and 592 μm, respectively.

[0188] [Comparative Synthesis Example 1: (Meth)acrylic Acid Modified Polycaprolactone Compound] No. C (*without hydrophilic groups)

[0189] In a four-necked separable flask, 18.81 parts by weight of Placcel 205 (manufactured by Daicel Co., Ltd., glycol-type polycaprolactone, molecular weight: 530), 18.81 parts by weight of chloroform, 8.77 parts by weight of triethylamine, and 0.03 parts by weight of MEHQ (hydroquinone monomethyl ether, polymerization inhibitor) were added. While stirring at 200 rpm and passing N2 containing 2% O2 through the flask, 6.55 parts by weight of acryloyl chloride were added dropwise. The mixture was cooled in a water bath to ensure that the exothermic reaction did not exceed 30°C. After the addition was complete, the stirring time was extended by 1 hour. The liquid temperature was further raised to 50°C and allowed to mature for approximately 2 hours. Next, 28.21 parts by weight of water-1 were added and stirred thoroughly. The mixture was then transferred to a separatory funnel, and the lower phase containing the modified polycaprolactone was extracted. Another 18.81 parts by weight of water-2 were added to homogenize the mixture. The mixture was then transferred back to a separatory funnel and allowed to stand overnight for further separation. After one night, the extracted solution was transferred to another four-necked flask, and chloroform was removed under reduced pressure while bubbling with N2 containing 2% O2, yielding a transparent orange polymer. H-NMR analysis revealed peaks originating from the acrylate groups, confirming the polymer as a polycaprolactone with the following structure, terminally modified to acrylate groups ((meth)acrylic acid modified polycaprolactone compound No. C).

[0190] [Chemical Formula 8]

[0191]

[0192] (In the formula, m+n=3.7)

[0193] [Comparative Example 1: Organosilicon elastomer particles No. 4 (free radical polymerization type)]

[0194] A methacrylic acid-modified silicone polymer and a (meth)acrylic acid-modified polycaprolactone compound NO.C were uniformly mixed at room temperature in a mass ratio of 30.0:70.0. The composition was then dispersed in a 25°C aqueous solution consisting of 0.27 parts by mass of Gohsenol EG-05C, 0.53 parts by mass of Gohsenol EG-18P, and 46 parts by mass of pure water. The mixture was further emulsified using a colloid mill, and then diluted with 526 parts by mass of pure water to prepare an emulsion. The emulsion was heated in a 1L flask to 70°C, and then 0.5 g of potassium persulfate (manufactured by Sigma-Aldrich) dissolved in 9.5 g of water was added dropwise over 1 minute. The emulsion was stirred at 70°C for 3 hours, followed by stirring at 80°C for 2 hours to carry out free radical polymerization, preparing a uniform aqueous suspension of silicone rubber particles. The aqueous suspension was then filtered and washed with 200 ml of ethanol and 100 ml of acetone. The residue was dried in an oven at 70°C for 5 hours to obtain silicone elastomer particles No. 5. The average primary and secondary particle sizes of the obtained silicone elastomer particles were 3.41 μm and 31.1 μm, respectively.

[0195] The average primary particle size and average secondary particle size of each particle obtained through Examples 1 to 3 and Comparative Example 1 are summarized in Table 1 below.

[0196] [Table 1]

[0197]

[0198] [Example of a cosmetic formulation]

[0199] The following are examples of formulations of cosmetics of the present invention capable of incorporating organosilicon elastomer particles, as one aspect of the present invention. However, the present invention is not limited to these examples.

[0200] [Examples 4-6, Comparative Example 2]

[0201] The composition described in Table 3 below was evaluated by experts based on their comparison of the user experience of loose powders using silicone elastomer particles.

[0202] [Table 2]

[0203]

[0204] (Preparation method)

[0205] 1. Mixed A phase.

[0206] 2. Mixed B phase.

[0207] 3. Stir phase A and phase B until homogeneous.

[0208] (Tactile feedback)

[0209] The smoothness of the coating sample was evaluated when it was applied to the inner forearm of 18 team members.

[0210] [Table 3]

[0211]

[0212] [Examples 7-9, Comparative Examples 3 and 4]

[0213] Experts compared and evaluated the user experience of oil-in-water sunscreens. Additionally, an SPF analyzer was used to compare and measure SPF and PA values.

[0214] [Table 4]

[0215]

[0216] (Preparation method)

[0217] Mixed A phase.

[0218] Mixed B phase.

[0219] While stirring phase A, slowly add phase B.

[0220] Add phase C to the above 4 and stir until homogeneous.

[0221] (Tactile feedback)

[0222] The spreadability and whitening residue of the samples were evaluated when they were applied to the inner forearm of 18 team members.

[0223] [Table 5]

[0224]

[0225] (SPF measurement)

[0226] Samples (2 mg / cm2) were coated on HelioScreen Labs HELIOPLATE HD6 and SPF and PA values ​​were measured using Labsphere UV-2000S (values ​​were the average of 30 sites, 3 coated samples and 10 test sites).

[0227] [Examples 10-12, Comparative Examples 5 and 6]

[0228] Experts conducted a comparative evaluation of the user experience of water-in-oil foundations.

[0229] [Table 6]

[0230]

[0231] (Preparation method)

[0232] Mixed A phase.

[0233] Mixed B phase.

[0234] A mixture of phase A and phase B.

[0235] While stirring phases AB, slowly add phase C.

[0236] Add phase D to the above 4 and stir until homogeneous.

[0237] (Tactile feedback)

[0238] The spreadability and wettability of the samples applied to the inner forearm of 18 team members were evaluated.

[0239] [Table 7]

[0240]

[0241] [Example 13, Comparative Examples 7 and 8]

[0242] A comparative evaluation of the user experience and soft-focus effect of water-in-oil type wrinkle concealers.

[0243] [Table 8]

[0244]

[0245] (Preparation method)

[0246] Mixed A phase.

[0247] Mixed B phase.

[0248] While stirring phase A, slowly add phase B.

[0249] Add phase C to the above 4 and stir until homogeneous.

[0250] (Tactile feedback)

[0251] The spreadability and wettability of the samples applied to the inner forearm of 18 team members were evaluated.

[0252] [Table 9]

[0253]

[0254] (Soft focus effect)

[0255] The material is coated onto a glass slide to a thickness of 10 micrometers, and the soft-focus effect is determined by the degree of blurring of the characters under the slide. The silicone elastomer particles involved in the embodiments of this invention have shown good results in any cosmetic composition.

[0256] [Table 10]

[0257]

[0258] <Enzymatic hydrolysis test of organosilicon elastomer particles>

[0259] [Examples 1-3 (silicone elastomer particles No. 1-3), Comparative Example 1 (silicone elastomer particles No. 4), and existing silicone elastomer products]

[0260] 0.1 g of the prepared silicone elastomer particles and the existing "Our Silicone Elastomer (Product)" (manufactured by Dow Toray Co., Ltd., product name: EP-9610 Cosmetic Powder; silicone elastomer particles obtained by hydrosilylation of alkenyl-modified polysiloxane and organohydrogen polysiloxane) were weighed and placed in microcentrifuge tubes. Type XIII lipase from *Pseudomonas* bacteria was mixed with 0.1 M phosphate-buffered saline (pH 7.4) to prepare an 8 U / mL enzyme solution. 1 mL of the prepared enzyme solution was added to each tube to prepare the test specimens. The test specimens were placed in a 37°C oven, with the enzyme replaced every 24 hours, for a maximum test duration of 96 hours. After the predetermined time, each sample was removed, washed with water, dried overnight, and then thoroughly dried in a vacuum oven. The weight of the absolutely dried sample was measured, and the rate of weight reduction was defined as the decomposition rate. This enzymatic hydrolysis test (test time - decomposition rate %) is shown below. Figure 1 As shown.

[0261] The silicone elastomer particles involved in these examples all exhibited weight loss over time in the presence of enzymes, suggesting their degradability. In particular, the silicone elastomer particles involved in Examples 1-3 all showed a high degradation rate exceeding 10% at the 96-hour time point, and the silicone elastomer particles involved in the embodiments of this application strongly indicate their biodegradability. On the other hand, existing silicone elastomers of this company do not exhibit biodegradability, and the silicone elastomer particles involved in the comparative examples, which lack hydrophilic groups in their crosslinking portions, showed a lower degradation rate compared to Examples 1-3.

Claims

1. A biodegradable organosilicon elastomer particle having a structure in which at least two silicon atoms within the organosilicon elastomer particle are cross-linked through a divalent organic group containing a hydrophilic group, and having within the organosilicon elastomer particle a structure composed of… -(R2SiO) m - (In the formula, R is an unsubstituted or halogen-substituted alkyl group with 1 to 20 carbon atoms, an aryl group with 6 to 22 carbon atoms, or a hydroxyl group with 1 to 20 carbon atoms, and m is a number in the range of 1 to 1000.) The structure of the polyorganosiloxane is represented.

2. The biodegradable organosilicon elastomer particles according to claim 1, characterized in that, The cross-linked structure, which is formed by divalent organic groups containing hydrophilic groups, is derived from a selection of... (A1) The two ends of the molecular chain are composed of R Alk R2SiO (where R is the formula) Alk A silyl-terminated crosslinking agent containing hydrosilylic groups, represented by an organic group containing a carbon-carbon double bond (R being alkyl or aryl), and exhibiting hydrosilylic reactivity. (A2) A crosslinking agent having at least two free radical polymerizable functional groups within its molecule and containing hydrophilic groups within its molecule. At least one crosslinking agent.

3. The biodegradable organosilicon elastomer particles according to claim 2, wherein, (A1) is a crosslinking agent containing a polyether structure within its (a1-1) molecule. (A2) is a crosslinking agent selected from (a2-1) a sorbitan fatty acid ester or a polyoxyalkylene sorbitan fatty acid ester having at least two free radical polymerizable functional groups in the molecule, and (a2-2) a crosslinking agent containing at least two free radical polymerizable functional groups and a polyether structure in the molecule.

4. The biodegradable organosilicon elastomer particles according to claim 2, wherein, (A1) is a crosslinking agent containing a polyoxyethylene-polyoxypropylene block copolymer structure within its (a1-1-1) molecule. (A2) The component is one or more crosslinking agents selected from (a2-1-1) sorbitan laurate, sorbitan stearate, sorbitan oleate, and polyoxyethylene sorbitan oleate, which have at least two free radical polymerizable functional groups in the molecule, and (a2-2-1) crosslinking agents containing at least two free radical polymerizable functional groups and a polyoxyethylene-polyoxypropylene block copolymer structure in the molecule.

5. The biodegradable organosilicon elastomer particles according to claim 1 or 2, wherein the crosslinking reactive organosilicon emulsion particles are obtained by crosslinking reactive organosilicon particles in water, wherein the crosslinking reactive organosilicon emulsion particles are obtained by emulsifying a crosslinking reactive organosilicon composition capable of crosslinking through one or more reactions selected from free radical polymerization and hydrosilylation of hydrogen atoms bonded to silicon atoms in water, wherein the crosslinking reactive organosilicon composition comprises at least: (A) at least one crosslinking agent selected from components (A1) and (A2) below: (A1) The two ends of the molecular chain are composed of R Alk R 1 2SiO (where R is the formula) Alk An organic group containing a carbon-carbon double bond, where R is an unsubstituted or halogenated alkyl group (1-20 carbon atoms), an aryl group (6-22 carbon atoms), or a hydroxyl group (representing a hydrosilylated reactive silyl-terminated crosslinking agent containing a hydrophilic group), and... (A2) A crosslinking agent having at least two free radical polymerizable functional groups in its molecule and containing hydrophilic groups in its molecule; (B) At least one reactive organopolysiloxane selected from components (b1) and (b2) below: (b1) Organohydrogen polysiloxanes having at least three silicon atoms bonded to hydrogen atoms within their molecules, and (b2) An organopolysiloxane having at least three organic groups selected from those containing methacryloyloxy and at least one organic group containing (meth)acryloyloxy; and (C) A curing agent selected from (c1) hydrosilylation catalyst and (c2) free radical polymerization initiator.

6. The biodegradable organosilicon elastomer particles according to claim 1, characterized in that, It is formed by cross-linking reactive emulsified particles in water. The cross-linking reactive emulsified particles are formed by emulsifying a cross-linking reactive organosilicon composition that can be cross-linked through hydrosilylation in water. The cross-linking reactive organosilicon composition contains: (A1) molecular chains with R at both ends. Alk R 1 2SiO (where R is the formula) Alk A crosslinking agent that is hydrosilylated and contains a hydrophilic group, represented by an organic group containing a carbon-carbon double bond (where R is an unsubstituted or halogen-substituted alkyl group with 1 to 20 carbon atoms, an aryl group with 6 to 22 carbon atoms, or a hydroxyl group with 1 to 20 carbon atoms). (b1) Organohydrogen polysiloxanes having at least three silicon atoms bonded to hydrogen atoms within their molecules; and (c2) Catalyst for hydrosilylation reaction.

7. The biodegradable organosilicon elastomer particles according to claim 1, characterized in that, It is formed by cross-linking reactive emulsified particles in water. The cross-linking reactive emulsified particles are formed by emulsifying a cross-linking reactive organosilicon composition that can be cross-linked through free radical polymerization in water. The cross-linking reactive organosilicon composition contains: (A2) a cross-linking agent having at least two free radical polymerizable functional groups in the molecule and containing hydrophilic groups in the molecule. (b2) An organopolysiloxane having at least three organic groups selected from those containing methacryloyloxy and at least one organic group containing (meth)acryloyloxy; and (c2) Free radical polymerization initiator.

8. The biodegradable organosilicon elastomer particles according to any one of claims 1 to 7, wherein, The average primary particle size, as determined by laser diffraction scattering, is 0.5–20 μm.

9. The biodegradable organosilicon elastomer particles according to any one of claims 1 to 7, wherein, The JIS-A hardness, measured by curing the free radical polymerizable polycarbonate-modified organosilicon compound used to form particles into a sheet, is in the range of 10 to 80.

10. The biodegradable organosilicon elastomer particles according to any one of claims 1 to 7, wherein, It has a structure in which part or all of its surface is covered by one or more of organopolysiloxane resins, silica and other organosilicon elastomer particles.

11. The biodegradable organosilicon elastomer particles according to any one of claims 1 to 7, wherein, The particles have a mesoporous structure.

12. The biodegradable organosilicon elastomer particles according to any one of claims 1 to 7, wherein, The particles contain an oil that is liquid at 40°C.

13. The biodegradable organosilicon elastomer particles according to any one of claims 1 to 12, wherein, It possesses the following properties: the divalent organic groups containing hydrophilic groups within the particles are active in biodegradation reactions; in a biodegradable environment, the cross-linked structure formed between silicon atoms within the particles cracks at least partially, and its primary particles break down with the generation of non-cross-linked polyorganosiloxanes.

14. A cosmetic ingredient containing biodegradable organosilicon elastomer particles as described in any one of claims 1 to 13.

15. A cosmetic composition comprising the biodegradable organosilicon elastomer particles according to any one of claims 1 to 13.

16. An organic resin additive containing biodegradable organosilicon elastomer particles as described in any one of claims 1 to 13.

17. An organic resin containing biodegradable organosilicon elastomer particles as described in any one of claims 1 to 13.

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