JP2008184435A - Ultraviolet ray-shielding resin particles and cosmetic blended with them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple composition of inorganic composite resin particles without skin irritation and highly transparent in visible light region, and excellent in light resistance and ultraviolet ray-shielding effect, and cosmetics with high transparency in visible light and excellent in ultraviolet ray-shielding effect. <P>SOLUTION: The thermoplastic resin particles have primary particle sizes of 2-50 nm and contain zinc oxide and/or titanium oxide with almost spherical average particle sizes of 1-20 μm, and cosmetics are blended with the resin particles. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a substantially spherical resin particle that is less irritating to the skin, transparent in the visible range, and has an ultraviolet shielding property, and a cosmetic containing the same.

In recent years, needs for cosmetics have been diversified, and more characteristics than ever have been demanded. It is also important to make the cosmetics less irritating to the skin.
For this purpose, there is an attempt to contain an inorganic filler such as a pigment inside the thermoplastic resin particles so as not to directly touch the skin. Examples of such encapsulated composite powder include composite particles in which titanium oxide or zinc oxide fine powder is dispersed inside resin powder (Patent Document 1), and composite particles in which colored pigment is dispersed inside resin powder. There are published applications relating to inclusion type composite powders such as (Patent Document 2). However, in Patent Document 1, in order to obtain an ultraviolet blocking effect, slipperiness, water repellency and oil repellency, (1) a titanium oxide or zinc oxide powder is dispersed inside the resin powder; Zirconium oxide powder is supported on the surface of the powder, (3) and then the surface of (2) is surface treated with aluminum oxide, and (4) the powder obtained in (3) is further hydrophobized with silicone oil etc. It requires a complicated particle composition. Moreover, in patent document 1 or 2, the combination of a thermoplastic resin and a filler was limited. A substantially spherical composite powder having a desired particle size by freely combining a thermoplastic resin and an additive is strongly desired as a component to be blended in cosmetics.
In order to solve this problem, the present inventors manufactured a fine spherical composite powder in which a filler such as a color pigment and an extender pigment was dispersed in a thermoplastic resin, and disclosed a cosmetic containing the same. (See Patent Document 3). Patent Document 3 discloses an embodiment in which a color pigment such as titanium white is dispersed in a thermoplastic resin.

  In recent years, with the deterioration of the global environment, especially the destruction of the ozone layer, the amount of ultraviolet rays reaching the ground surface has increased, and there is a tendency for the incidence of skin cancer to increase. Composite particles for blending in cosmetics such as foundations useful as sunscreen agents that shield ultraviolet rays are known (see Patent Document 4). This Patent Document 4 has base material particles made of nylon resin or the like, and a powder of zirconium oxide or aluminum oxide is supported on the surface of the base material particles, and inside the base material particles is titanium oxide or oxide. Composite particles in which zinc powder is dispersed are disclosed. Such composite particles have low transmittance in the visible region (400 to 700 nm) as low as 25% or less, and cannot be said to have sufficient ultraviolet shielding properties, and complicated production processes for supporting zirconium oxide on the particle surface are complicated. It is.

  An ultraviolet shielding agent having a high visible light transmittance and an excellent property is desired, and an organic ultraviolet absorber has a light absorption property close to this requirement. For example, organic ultraviolet absorbers such as benzophenones and benzotriazoles can be candidates. However, these organic ultraviolet absorbers are not sufficiently light-resistant and are highly likely to irritate human skin. Further, even when blended with thermoplastic resin particles, the compatibility between the absorbent and the resin is not sufficient, and a bleeding phenomenon (bleed out) often occurs.

JP-A-9-30935 JP-A-10-231232 JP 2001-199836 A Japanese Patent Laid-Open No. 2-49717

The problems to be solved by the present invention are as follows. First, inorganic composite resin particles having a simple composition having no skin irritation, excellent light resistance, high transparency in the visible region, and excellent ultraviolet shielding properties. Secondly, it is to provide cosmetics such as a foundation having high visible light permeability and excellent ultraviolet shielding properties.
Further details of the invention will become apparent from the following detailed description.

The above-mentioned problems of the present invention have been solved by means described in the following items 1), 7) and 8). The following are listed together with items 2) to 6) which are preferred embodiments.
Item 1) A resin characterized by containing zinc oxide and / or titanium oxide having a primary particle diameter of 2 to 50 nm inside a thermoplastic resin particle, an average particle diameter of 1 to 20 μm and being substantially spherical. particle,
Item 2) Resin particles according to Item 1) containing zinc oxide and / or titanium oxide having a primary particle diameter of 5 to 20 nm,
Item 3) Resin particles according to Item 1) or 2) containing 1 to 75 parts by weight of zinc oxide and / or titanium oxide with respect to 100 parts by weight of the thermoplastic resin,
Item 4) Resin particles according to any one of Items 1) to 3) containing zinc oxide and / or titanium oxide, which are subjected to a surface treatment with a surface treatment agent for inorganic particles.
Item 5) The resin particles according to any one of Items 1) to 4) containing zinc oxide and titanium oxide,
Item 6) The thermoplastic resin is selected from the group consisting of polyolefins, polyamides, ethylene / vinyl acetate copolymer (EVA), polymethyl methacrylate (PMMA), and ethylene / (meth) acrylate copolymer. Item 1) to 5) Resin particles according to any one of
Item 7) A cosmetic comprising the resin particles according to any one of Items 1) to 6),
Item 8) 1) A thermoplastic resin composition substantially consisting of at least one of a thermoplastic resin and an ultraviolet-absorbing inorganic oxide particle having a primary particle diameter of 2 to 50 nm is incompatible with the composition. Steps (1) and 2) obtained resin particles obtained by kneading together with a dispersion medium at a temperature equal to or higher than the melting point of the composition and dispersing the resin particles made of a thermoplastic resin composition having an average particle size of 1 to 20 μm. And a step (2) of cooling the resin to a temperature equal to or lower than its melting point to obtain a substantially spherical resin particle having an average particle diameter of 1 to 20 μm.

  According to the present invention, it was possible to provide resin particles that have no skin irritation, excellent ultraviolet durability, high transparency in the visible region, excellent ultraviolet absorption, and no bleeding out. In addition, according to the present invention, cosmetics such as a foundation having a high visible light permeability and an excellent ultraviolet shielding property and having a good stretch were obtained.

The present invention is described in detail below.
The resin particles of the present invention are resin particles having excellent ultraviolet shielding properties, and contain zinc oxide and / or titanium oxide having a primary particle size of 2 to 50 nm inside the thermoplastic resin particles, and have an average particle size of It is 1-20 micrometers and is substantially spherical. The resin particles of the present invention use a thermoplastic resin, not a thermosetting resin, have a substantially spherical shape including a true sphere, and have an average particle diameter of 1 to 20 μm. The resin particles contain ultraviolet absorbing inorganic oxide particles in a dispersed state therein. As described above, zinc oxide and / or titanium oxide having a primary particle diameter of 2 to 50 nm is preferable as the inorganic oxide.

  The thermoplastic resin is a resin that is plasticized by heating, and functions as a binder (binder) that encapsulates ultraviolet-absorbing inorganic oxide particles in order to form resin particles. As the thermoplastic resin, many amorphous transparent synthetic polymers are preferable. Examples of the thermoplastic resin that can be used in the present invention include polyolefins such as polyethylene and polypropylene; polyamides including various nylons such as nylon 6, nylon 66, nylon 610, nylon 612, nylon 11, nylon 12, and nylon 46; polylactic acid Copolymer of ethylene and ethylenically unsaturated compound such as ethylene / vinyl acetate copolymer (EVA), ethylene / acrylic acid copolymer, ethylene / propylene copolymer; polymethyl methacrylate (PMMA), ethylene / (meth) acrylic acid Homopolymers or copolymers of (meth) acrylic esters such as ester copolymers, methyl acrylate / methyl methacrylate copolymers; polyesters such as polyethylene terephthalate; polycarbonates; polyvinyl chloride, polystyrene Homopolymers or copolymers of ethylenically unsaturated compounds substituted with halogen atoms or aromatic groups such as polytetrafluoroethylene and polyvinylidene fluoride; saponified products of polyvinyl acetate, polyvinyl butyral, polyacetal, etc. Copolymers of polyvinyl alcohols and ethylene; polysulfones; copolymers of unsaturated acrylics such as acrylonitrile / styrene copolymers and ABS resins (acrylonitrile / butadiene / styrene copolymers); thermoplastic elastomers such as styrene / butadiene block polymers Can be illustrated. Among these thermoplastic resins, polyolefins, polyamides, ethylene / vinyl acetate copolymer (EVA), polymethyl methacrylate (PMMA), and ethylene / (meth) acrylic acid ester copolymers are more preferable, and polyamides Is particularly preferred.

  From the viewpoint of producing the resin particles of the present invention by the melt dispersion method described later, the melting point of the thermoplastic resin is preferably in the range of 30 to 300 ° C, more preferably in the range of 30 to 200 ° C. Here, the melting point refers to a value obtained by differential scanning calorimetry (DSC).

  The thermoplastic resin may be a mixture of two or more of the same or different thermoplastic resins. When the components of the different thermoplastic resin mixture (polymer blend) are incompatible, it is preferable to improve the dispersion of both phases using a compatibilizing agent. More preferably, a so-called polymer alloy having a controlled mixing state can be used in the present invention. Heat resistance, toughness, and granulation properties can be improved by using a polymer alloy. Examples of polymer alloys include polyphenylene oxide (PPO) / polystyrene (PS), polybenzimidazole (PBI) / polyimide (PI), PPO / ABS, ABS / polycarbonate (PC), polybutylene terephthalate (PBT) / PC, PET / PC, PBT / PET, PBI / PI, nylon / modified polyolefin, PBT / modified polyolefin, nylon / PPO, ABS / nylon, ABS / PBT, nylon / PPO, nylon / ABS, nylon / PC Other specific examples are described in, for example, the Society of Polymer Science, Advanced Polymer Materials Series 3 “High Performance Polymer Alloys” (1993, Maruzen).

The resin particles of the present invention are preferably spherical or substantially spherical. The substantially spherical shape means that the axial ratio is 0.5 to 2, and preferably 0.75 to 1.33.
The resin particles used in the present invention have an average particle diameter of 1 to 20 μm and preferably 5 to 10 μm. An average particle diameter means the weight average value of a long axis. The particle diameter can be measured with an optical microscope or an electron microscope. When the average particle diameter is in the above range, it is preferable because it has a rolling effect, the spread of the blended cosmetics is good, and gives a free feeling.

The resin particles of the present invention contain an ultraviolet-absorbing inorganic oxide in a dispersed state therein. Examples of the inorganic oxide include so-called ultrafine zinc oxide and / or ultrafine titanium oxide. Zinc oxide is preferable, and it is also preferable to use zinc oxide in combination with zinc oxide.
Recently, ultrafine zinc oxide produced industrially in Japan has a fine particle size of 2 to 50 nm, a sharp particle size distribution, and the zinc oxide that has been used as a white pigment in the past. Compared to a particle size of 450-600 nm, it is orders of magnitude smaller and is transparent in the visible range (400-700 nm) when dispersed in a resin or liquid dispersion medium, but has excellent UV shielding properties, antibacterial / deodorant / deodorant It has the following characteristics. The absorption edge of zinc oxide of this ultrafine particle is about 380 nm and absorbs not only UV-B (290 to 320 nm) but also UV-A (320 to 400 nm), so that it has the property of shielding ultraviolet rays with a wide wavelength range. is there. On the other hand, the particle diameter is one tenths of visible light and the refractive index is as low as 1.9. Therefore, even when dispersed in resin particles, there is little visible light scattering, and it is colorless and transparent to the naked eye. New resin particles.
Ultrafine zinc oxide is commercially available, such as ZnO-310, ZnO-350, ZnO-410 from Sumitomo Osaka Cement Co., Ltd., and FINEX series (FINEX-30, FINEX- 30S-LP2, FINEX-30W-LP2, FINEX-50, FINEX-50S-LP2, etc.).

  The ultrafine zinc oxide is preferably subjected to a surface treatment, which can be adopted by a known inorganic surface treatment or an organic surface treatment, and a surface treatment with an organic silicon compound is more preferred. In addition to the surface treatment with the surface treatment agent, coating with a fatty acid such as lauric acid or stearic acid can be appropriately performed. The coating of ultrafine particles with fatty acid can be achieved by immersing the fine particles in a solution of fatty acid in isopropyl alcohol and then drying.

Ultrafine titanium oxide has a fine particle size of 2 to 50 nm, has a sharp particle size distribution, and is compared with the particle size of 200 to 300 nm of titanium oxide for pigments conventionally used as white pigments. When it is dispersed in a resin or liquid dispersion medium, it is transparent in the visible range (400 to 700 nm), but has excellent ultraviolet shielding properties and antibacterial, deodorant, and deodorant properties. The absorption edge of titanium oxide of this ultrafine particle is about 350 nm, and has a property of shielding UV-B (290 to 320 nm) ultraviolet rays. Its particle size is a few tenths of visible light, and its refractive index is 2.7.
Ultrafine titanium oxide has a spindle shape, and its particle size is, for example, 30 × 90 nm. It has a high shielding property in the UVB region and also has visible light transparency. Examples of commercially available products include TTO-55, 51, F, and S series from Ishihara Sangyo Co., Ltd., and STR-60 and STR-100 from Sakai Chemical Industry Co., Ltd.
Ultrafine titanium oxide is also preferably subjected to surface treatment, and examples thereof include inorganic surface treatment with aluminum oxide and organic surface treatment with organopolysiloxane. By surface treatment, aggregation of primary particles can be prevented, and dispersion into a thermoplastic resin can be facilitated.

  The resin particles of the present invention preferably contain 1 to 75 parts by weight of ultrafine zinc oxide and / or titanium oxide with respect to 100 parts by weight of the thermoplastic resin. The content of zinc oxide is preferably 10 to 40 parts by weight, and more preferably 20 to 30 parts by weight. By setting it as this compounding quantity, ultraviolet-ray shielding property and visible-light transmittance can be ensured. Further, the more preferable blending amount of 20 to 30 parts by weight can suppress the exposure of the ultrafine zinc oxide to the resin particle surface, and elution of zinc ions when the zinc oxide comes into contact with moisture in the cosmetic. No. Since zinc ions significantly reduce the stability of the thickener blended in cosmetics, the absence of zinc ion elution is extremely important in blending into cosmetics.

  Titanium oxide mainly shields UV-B and can also be used as extender pigments. Therefore, depending on whether transparency is important or whether the function of extender pigments is added while blocking UV-B, preferred blending amount Is different. When UV-B shielding and transparency are compatible, the preferred blending amount is 10 to 20 parts by weight. When UV-B shielding and extender functions are both compatible, the preferred blending amount is 50 to 75 parts by weight. is there. As the amount of titanium oxide increases, the proportion of titanium oxide exposed on the surface of resin particles increases, but titanium oxide does not react with moisture in cosmetics, and therefore ions that affect the stability of the thickener. Therefore, a large amount of 75 parts by weight can be blended.

The ultrafine particles of zinc oxide and titanium oxide filled in the resin particles of the present invention are different in particle diameter from titanium oxide (titanium white) and zinc oxide used as a color pigment. Note that the absorption intensity is quite different.
Ultrafine zinc oxide and / or ultrafine titanium oxide are superior to organic ultraviolet absorbers in light resistance and heat resistance to ultraviolet rays and have the advantage of not bleeding out from resin particles or foundation films.

  In the cosmetic of the present invention, two or more different resin particles having different functions or the same function can be used in combination as necessary. The ultrafine zinc oxide or the like to be filled is preferably contained inside the spherical particles of the thermoplastic resin. In addition, it does not exclude that some of these ultrafine particles are also present on the surface of the resin particles.

  The resin particles of the present invention are preferably substantially composed of a thermoplastic resin and an ultraviolet shielding inorganic oxide. “Consisting essentially of a thermoplastic resin and an ultraviolet shielding inorganic oxide” means that the other components are 20% by weight or less, preferably 10% by weight or less, and the properties of the ultraviolet shielding inorganic oxide are It means not hindered.

The production method of the resin particles used in the present invention can be exemplified by a production method including the following steps 1) and 2):
1) A thermoplastic resin composition consisting essentially of at least one of a thermoplastic resin and ultraviolet absorbing inorganic oxide particles having a primary particle diameter of 2 to 50 nm, together with a dispersion medium incompatible with this composition Steps (1) for kneading at a temperature equal to or higher than the melting point of the composition and dispersing the resin particles made of a thermoplastic resin composition having an average particle diameter of 1 to 20 μm, and 2) A step (2) of cooling to a temperature of 2 to form a substantially spherical resin particle having an average particle diameter of 1 to 20 μm.
This melt-kneading method is described in Patent Document 3.

  In the dispersion step of the step (1), the dispersion medium forms a continuous phase for dispersing the thermoplastic resin composition in the fine particles, and is not compatible with the thermoplastic resin. “Not having compatibility” means having no solubility of 1% by weight or more at the heating temperature in the step (1). The dispersion medium of the present invention may be a mixture of two or more dispersion media, and is desirably not compatible with the thermoplastic resin composition over a range of room temperature to the heating temperature in step (1). The dispersion medium of the present invention is used in a volume of 0.5 to 5 times the thermoplastic resin composition.

  Preferred examples of the dispersion medium used in the present invention include polyalkylene oxides such as polyethylene oxide, polyethylene glycol, polyvinyl alcohol and derivatives thereof (acetalized products, etc.), polybutene, wax, natural rubber, synthetic rubber such as polybutadiene and styrene. -Butadiene copolymer rubber, petroleum resin, etc., and these can be used alone or in combination. Polyalkylene oxides having different degrees of polymerization are commercially available. By appropriately combining these components, the dispersion medium can be adjusted so as to have a desired viscoelasticity at the dispersion temperature in step (1). it can.

  In the present invention, the melting point of the thermoplastic resin composition refers to a value measured by a differential scanning calorimetry (DSC) method. The melting point of the thermoplastic resin composition substantially composed of the thermoplastic resin and the inorganic filler can be approximated by the melting point of the thermoplastic resin. The above melting points are described as melting points of various thermoplastic resins in handbooks, manufacturer's technical data, etc. (for example, practical plastic dictionary, material edition, supplementary revision, page 320, Table 1-4 (1993)). For example, the melting point of nylon 12 is about 180 ° C. In the present invention, the melting point of the thermoplastic resin is preferably 30 ° C. or more and 300 ° C. or less. The temperature of the dispersing step is preferably 10 to 200 ° C. higher than the melting point of the thermoplastic resin to be used, preferably 20 to 150 ° C. and preferably mixed. If the temperature is too high, the thermoplastic resin composition is difficult to disperse in the fine particles and tends to become entangled fibers, and if the heating temperature is too high, thermal decomposition or the like occurs, which is not preferable.

  In the method for producing a substantially spherical composite powder used in the present invention, the method and apparatus for dispersing the resin composition in fine particles in the dispersion medium in the step (1) is not particularly limited. For example, it can be dispersed by a roll, a Banbury mixer, a kneader, a single screw extruder, a twin screw extruder, or the like. In the granulation method of the present invention, it is considered that the granulation method belongs to wet stirring granulation, and the shearing force by stirring, which is a force for splitting fine particles, and the viscoelasticity and interfacial tension of the composition, which is a force for holding fine particles It is thought that the particle size is determined by the balance. In order to obtain a uniform particle size distribution, it is preferable to uniformly shear the composition by stirring. For this purpose, a closed disperser is used and the temperature distribution inside the disperser is made uniform. It is preferable.

  In the present invention, after step (2), the mixture of the thermoplastic resin composition and the dispersion medium is cooled to the melting point or lower, and then the developing solvent which is a poor solvent for the composition and a good solvent for the dispersion medium, and the mixture. May be mixed to form a suspension of the composite powder. In this case, after cooling the mixture, the mixture may be pulverized with a crusher or the like, pelletized with a pelletizer, or formed into a sheet with an extruder, a roll, or the like and then immersed in a developing solvent.

  As a developing solvent, water, an organic solvent, and a mixture thereof can be used. When polyalkylene oxides are used as the dispersion medium, water can be used as a developing solvent. The target substantially spherical composite powder can be separated from the suspension of the composite powder by centrifugation, filtration, or a combination of these methods. The separated composite powder is used after drying if necessary.

  According to the method for producing a composite powder of the present invention, substantially spherical particles (hereinafter also simply referred to as “spherical particles”) having an average particle diameter of 1 μm or more and 20 μm or less can be obtained. Here, “substantially spherical” refers to particles having a ratio of three orthogonal axes of 0.5 to 2 or less, preferably 0.75 to 1.33. Needless to say, the substantially spherical particles include true spherical particles. The obtained resin particles can be classified into a desired average particle diameter range by classification as necessary. For classification, a known dry or wet classification method and classification apparatus can be used.

For cosmetic blending, resin particles having an average particle diameter of 1 to 20 μm are generally used. More preferably, resin particles having an average particle diameter of 5 to 10 μm are used. Synthetic polymer spherical resin particles have a rolling effect, and since the free energy on the surface of the resin is small as represented by polyethylene, nylon, etc., they have excellent surface lubricity and a low coefficient of friction with other materials. . Therefore, a cosmetic compounded with synthetic polymer spherical resin particles has a good spread and a smooth feel, giving the user a comfortable feeling of application and use.
In addition, when blended into a press cosmetic product, the spherical resin fine particles disperse and relax the internal stress of the press-molded product, so that pressability and workability are improved and effective in preventing cracks. The relaxation effect of internal stress is also useful for preventing cracking when a pressed product such as a solid foundation is accidentally dropped during use, and can provide high drop impact resistance.
The spherical resin particles can add an ultraviolet shielding function by the filled inorganic oxide while maintaining the above-mentioned characteristics such as coating feeling, feeling of use, pressability, and impact resistance. In addition, for cosmetics, powders, oils, surfactants, UV absorbers, thickeners, bactericides, preservatives, antioxidants, fragrances, and pigments that have been used in cosmetics are added at the same time. be able to.
As described in paragraph 0017, the spherical resin particles of the present invention are particularly effective in suppressing the interaction with the thickener.
JP-A-2002-370920, JP-A-2006-28035, JP-A-5-262622, etc. describe examples of cosmetics formulated with resin particles and effects on touch.

In the present invention, a preferable example of elements such as a thermoplastic resin, a filler, a dispersion medium, a developing solvent, etc., or an aspect in which two or more arbitrary elements are combined from a preferable range of process conditions is a further preferable embodiment.
Examples of the present invention will be given below, but the present invention is not limited thereto.

Example 1: Zinc oxide-encapsulated nylon particles 1
Daicel Degussa Co., Ltd. Daiamide 1640 (nylon 12) 0.75 Kg and ultrafine zinc oxide (Sakai Chemical Industry Co., Ltd. FINEX-50S-LP2; average particle size 20 nm) 0.25 Kg, Meisei Chemical Industry After mixing well with 1.3 Kg of polyethylene oxide R150 manufactured by Co., Ltd., it is kneaded while uniformly heating to 230 ° C. in a biaxial pressure kneader to disperse the zinc oxide inside. Manufactured. The obtained mixture was cooled to about 150 ° C., and then mixed with 20 liters of water as a dispersion medium to obtain a suspension of ultrafine zinc oxide-containing nylon composite powder. The target composite powder was separated by centrifugal separation and then dried by heating to obtain substantially spherical nylon particles 1 having an average particle diameter of about 5 μm and containing ultrafine zinc oxide.

Example 2: Zinc oxide-encapsulated nylon particles 2
In the production of the nylon particles 1 described above, the ultrafine zinc oxide (ZincO-350 manufactured by Sumitomo Osaka Cement Co., Ltd .; particle diameter 10 to 30 nm) 0.25 kg was used in the same manner as the ultrafine zinc oxide. Substantially spherical nylon particles 2 having an average particle diameter of about 7 μm and containing ultrafine zinc oxide were obtained.

Example 3: Titanium oxide-encapsulated nylon particles 3
Other than using 0.75 kg of Daiamide 1640 (nylon 12) manufactured by Daicel Degussa and 0.25 kg of ultrafine titanium oxide (STR-60C-LP manufactured by Sakai Chemical Industry Co., Ltd .; particle size 30 × 90 nm) In substantially the same manner, substantially spherical nylon particles 3 having an average particle diameter of about 6 μm and containing ultrafine titanium oxide were obtained.

Example 4
The following solid foundation 1 was produced using the above-described zinc oxide-containing nylon particles 1.
(Solid foundation 1)
Zinc oxide-encapsulated nylon particles 1 15% by weight
Titanium oxide for pigments 8% by weight
Sericite 45.2% by weight
Talc 10% by weight
Mica titanium 2wt%
Bengala 2% by weight
Yellow iron oxide 3.5% by weight
Ultramarine 1% by weight
Aluminum stearate 1% by weight
Dimethylpolysiloxane 5% by weight
Squalane 7% by weight
Paraben 0.2% by weight
Fragrance 0.1% by weight
The above components were mixed using a Henschel mixer, and oil was added to this and further mixed. This was filled in an intermediate dish to obtain a solid foundation 1.

Example 5
(Solid foundation 2)
A solid foundation 2 was produced in the same manner as in Example 1 except that the zinc oxide-containing nylon particles 2 were used instead of the zinc oxide-containing nylon particles 1.

Example 6
The following solid foundation 3 was produced using the above-described zinc oxide-encapsulated nylon particles 1 and titanium oxide-encapsulated nylon particles 3.
(Solid foundation 3)
Zinc oxide-encapsulated nylon particles 1 5% by weight
Titanium oxide-encapsulated nylon particles 3 10% by weight
Titanium oxide for pigments 8% by weight
Sericite 45.2% by weight
Talc 10% by weight
Mica titanium 2wt%
Bengala 2% by weight
Yellow iron oxide 3.5% by weight
Ultramarine 1% by weight
Aluminum stearate 1% by weight
Dimethylpolysiloxane 5% by weight
Squalane 7% by weight
Paraben 0.2% by weight
Fragrance 0.1% by weight
The above components were mixed using a Henschel mixer, and oil was added to this and further mixed. This was filled in an intermediate dish to obtain a solid foundation 3.

Example 7: Zinc oxide-encapsulated polyethylene particles 4
In the production of the nylon particles 1, zinc oxide was used in exactly the same manner except that 0.75 kg of diamide 1640 (nylon 12) was used and 0.75 kg of low density polyethylene having a Shore hardness of 42 on the D scale was used. Thus, substantially spherical polyethylene particles 4 having an average particle diameter of about 10 μm were obtained.

Example 8:
The following solid foundation 4 was produced using the nylon particles 1 and the polyethylene particles 4 described above.
(Solid foundation 4)
Zinc oxide-encapsulated nylon particles 1 5% by weight
Zinc oxide-encapsulated polyethylene particles 4 10% by weight
Titanium oxide for pigments 8% by weight
Sericite 45.2% by weight
Talc 10% by weight
Mica titanium 2wt%
Bengala 2% by weight
Yellow iron oxide 3.5% by weight
Ultramarine 1% by weight
Aluminum stearate 1% by weight
Dimethylpolysiloxane 5% by weight
Squalane 7% by weight
Paraben 0.2% by weight
Fragrance 0.1% by weight
The above components were mixed using a Henschel mixer, and oil was added to this and further mixed. This was filled in an intermediate dish to obtain a solid foundation 4.

  Obtained zinc oxide-encapsulated nylon particles 1 (Example 1), particles of Daiamide 1640 (nylon 12) made by Daicel Degussa Co., Ltd., which do not contain a metal oxide (Comparative Example 1), and a resin not encapsulated in resin Chemical Industry Co., Ltd. ultrafine zinc oxide FINEX-50S-LP2 (Comparative Example 2) was mixed and dispersed in trioctanoin (Nisshin Oilio Group Co., Ltd.) and then applied to a quartz plate with a thickness of 20 μm. Then, the spectral transmittance of this test piece was measured. The mixing dispersion ratio of trioctanoin and each particle was 25% by weight for each particle with respect to 75% by weight for trioctanoin.

The spectral transmittance of each test piece is shown in FIG.
In Example 1, the transparency in the visible light region was maintained well, and at the same time, the transmission in the ultraviolet region was suppressed. In Comparative Example 1, although the transparency in the visible light region was good, the effect of suppressing transmission in the ultraviolet region was not exhibited. In Comparative Example 2, transparency in the visible light region and high transmission suppression in the ultraviolet region are observed. However, as described in paragraph 0017, there is a problem of elution of zinc ions for use as a cosmetic.

The evaluation feeling of the solid foundation obtained in the examples was applied to the face of 10 evaluation panelists with a sponge, and the number of panelists who felt that the feeling of elongation, smoothness and softness at that time was good was counted. The evaluation was made according to the criteria shown in Table 1 below. The evaluation results are shown in Table 2.
In addition, the comparative example 3 is the prescription which did not mix | blend the resin particle in Example 4. FIG.

  The cosmetics containing the zinc oxide-encapsulated nylon particles, the titanium oxide-encapsulated nylon particles, and the zinc oxide-encapsulated polyethylene particles of the present invention were found to have excellent stretch feeling, smooth feeling, and soft feeling when applied.

It is a figure which shows the spectral transmittance | permeability of the thermoplastic resin particle which contains a zinc oxide or a titanium oxide in particle | grain inside.

Claims (8)

  A resin particle comprising zinc oxide and / or titanium oxide having a primary particle diameter of 2 to 50 nm in a thermoplastic resin particle, an average particle diameter of 1 to 20 μm and a substantially spherical shape.   The resin particles according to claim 1, comprising zinc oxide and / or titanium oxide having a primary particle diameter of 5 to 20 nm.   The resin particle according to claim 1 or 2, comprising 1 to 75 parts by weight of zinc oxide and / or titanium oxide with respect to 100 parts by weight of the thermoplastic resin.   The resin particle according to any one of claims 1 to 3, comprising zinc oxide and / or titanium oxide subjected to a surface treatment.   Resin particle | grains as described in any one of Claims 1-4 containing a zinc oxide and a titanium oxide.   The thermoplastic resin is selected from the group consisting of polyolefins, polyamides, ethylene-vinyl acetate copolymer (EVA), polymethyl methacrylate (PMMA), and ethylene / (meth) acrylic acid ester copolymers. The resin particle as described in any one of -5.   Cosmetics which mix | blended the resin particle as described in any one of Claims 1-6.   1) A thermoplastic resin composition consisting essentially of at least one of a thermoplastic resin and ultraviolet absorbing inorganic oxide particles having a primary particle diameter of 2 to 50 nm, together with a dispersion medium incompatible with this composition Steps (1) and 2) of dispersing the resin particles obtained from the thermoplastic resin composition having an average particle diameter of 1 to 20 μm by kneading at a temperature equal to or higher than the melting point of the composition. A step (2) of cooling to a temperature of 2 to form a substantially spherical resin particle having an average particle diameter of 1 to 20 μm.

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