JPH09255937A - Ultraviolet-protecting particle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain ultraviolet-protecting particles lightened in skin irritation caused by an ultraviolet protectant and having improved biocompatibility by chemically bonding a poly-α-amino acid to an ultraviolet protectant. SOLUTION: Ultraviolet-protecting particles each of which is composed of a poly-α-amino acid and an ultraviolet protectant chemically bonded thereto and which have a mean particle diameter of 0.01-100μm are obtained by adding 0.05-100 pts.wt. amino ultraviolet protectant and a dehydratively condensing agent to a liquid prepared by dissolving and/or suspending 100 pts.wt. poly-α- amino acid particles obtained by emulsion-polymerizing an amino acid N- carbonic anhydride in an organic solvent and reating the resultant mixture.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to polyamino acid particles having an ultraviolet ray-preventing property.

[0002]

2. Description of the Related Art Sun rays contain ultraviolet rays that cause red spots (sunburn) on human skin and cause spots, freckles, etc., and prevent ultraviolet rays to shield or absorb such ultraviolet rays. Cosmetics containing agents are used. Examples of the anti-ultraviolet agent include an organic anti-ultraviolet agent that absorbs ultraviolet rays and inorganic pigments such as titanium dioxide, zinc oxide and iron oxide that shield ultraviolet rays. Many organic UV protectants are irritating to the skin,
If used as it is with other cosmetic base materials, it may irritate the skin. Therefore, in order to prevent direct contact between such an organic ultraviolet protection agent and the skin,
There has been proposed a method in which an ultraviolet protective agent is dispersed inside resin particles and restrained before use. For example, Japanese Patent Publication Sho 62-51931
JP-A-62-198612 and the like disclose resin particles encapsulating such an organic ultraviolet protection agent. By restraining the organic UV inhibitor in the resin particles in this way, irritation should be reduced as compared with cosmetics in which the UV inhibitor is directly blended, but actually using such resin particles However, UV protection may still irritate the skin. That is, the organic UV protection agent is only physically constrained by the engaging force inside the pores existing in the particles formed from this resin, apart from the resin structure forming the particles, and the makeup inside the pores. If an oily base material or the like of the material invades, a few% of the organic ultraviolet protection agent may move out of the particles due to the oily base material. In this way, the anti-ultraviolet agent eluted outside the particles causes skin irritation. On the other hand, by coating the core material composed of the organic UV protection agent and the resin with a layer not containing the organic UV protection agent, for example, a layer composed of (meth) acrylic resin or styrene resin, the UV protection agent Japanese Patent Application Laid-Open No. 7-291837 discloses a method of suppressing the elution of the particles outside the particles. However, this method may not be able to sufficiently suppress the elution of the ultraviolet protective agent to the outside of the particles, and basically, the (meth) acrylic resin or the styrene resin has low biocompatibility, and the resin itself is not suitable for the skin. There is also a problem that stimulates people. On the other hand, an inorganic pigment hides the skin and blocks ultraviolet rays, but when such an inorganic pigment is applied to the skin, it is whitened or colored, and therefore cannot be incorporated in a large amount in cosmetics.

[0003]

DISCLOSURE OF THE INVENTION The present invention has been made based on the above circumstances, and its object is to provide:
The purpose of the present invention is to obtain anti-UV particles that are basically biocompatible and that have less irritation to the skin caused by the anti-UV agent without lowering the anti-UV effect.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides an anti-UV particle comprising a poly-α-amino acid chemically bonded with an anti-UV agent. Hereinafter, the present invention will be described in detail. Examples of the poly-α-amino acid forming the ultraviolet protective particle of the present invention include glutamic acid-γ-ester, aspartic acid-β-ester, and other acidic amino acid-ω-esters (here, ester means methyl ester, ethyl ester and ethyl ester). Ester, propyl ester, butyl ester, octyl ester, 2-ethylhexyl ester, cyclohexyl ester, phenyl ester, benzyl ester, etc.).

The above-mentioned N-carbonic anhydride of α-amino acid (hereinafter referred to as "amino acid-NCA") may be an optically active substance, a racemate or a mixture thereof.
If necessary, two or more kinds can be used in combination. Further, other α-amino acid may be used in combination at a ratio of 70% by weight or less of the α-amino acid. Specific examples of other α-amino acids include neutral amino acids such as glycine, alanine, valine, norvaline, leucine, isoleucine, norleucine, phenylalanine, methionine and proline, N-carbobenzoxylysine, N-carbobenzoxyornithine. , N-acyl basic amino acids such as N-acetyllysine, and hydroxyl group-containing α-amino acid esters such as serine, threonine, cystine, and tyrosine (here, ester means methyl ester, ethyl ester,
Propyl ester, butyl ester, octyl ester, 2-ethylhexyl ester, cyclohexyl ester, phenyl ester, benzyl ester and the like are shown. ). As the ultraviolet protective agent used in the present invention, an organic compound having at least one amino group so that it can be dehydrated and condensed with the acidic polyamino acid is preferable. Examples of such an organic UV protection agent include 2-ethylhexyl-p-dimethylaminobenzoate, amyl-p-dimethylaminobenzoate, glyceryl-p-aminobenzoate, ethyl-p-dimethylaminobenzoate, ethyl-p-diethylamino. Examples thereof include benzoate, aminobenzoate-based UV protection agents such as glyceryl-mono-p-aminobenzoate, hindered amine-based UV protection agents, and the like. Of these, particularly preferred are aminobenzoate-based ultraviolet ray inhibitors. In the present invention, the UV inhibitor is bonded in an amount of 0.05 to 100 parts by weight, preferably 0.1 to 50 parts by weight, based on 100 parts by weight of the polyamino acid. The average particle diameter of the ultraviolet ray protective particles of the present invention is 0.01 to 100.
μm, preferably 0.05 to 50 μm. In addition, the coefficient of variation (CV) of the average particle diameter of the ultraviolet protective particles of the present invention.
The value) is 1 to 30%, preferably 1 to 20%.

The UV-preventive particles of the present invention are obtained by dissolving and / or suspending poly-α-amino acid particles obtained by emulsion polymerization of the above amino acid-NCA in an organic solvent,
It can be produced by adding a UV protection agent having an amino group and a dehydration condensation agent, and reacting the carboxy group of the poly-α-amino acid with the amino group of the UV protection agent. Water and / or an organic solvent can be used as a reaction medium when emulsion-polymerizing amino acid-NCA to produce poly-α-amino acid particles. The water and the organic solvent are preferably used in a weight ratio of water: organic solvent of 100: 0 to 50:50. When using an organic solvent,
The solubility of water under the condition of 1 atm and 25 ° C is 10 g /
It is preferably 100 ml or less, more preferably 5 g / 100 ml or less. The solubility of the water is 10
When an organic solvent exceeding g / 100 ml is used, a particulate polymer may not be obtained.

Specific examples of such organic solvents include chloromethane, dichloromethane, chloroform and 1,1-
Dichloroethane, 1,2-dichloromethane, 1,1,2
-Aliphatic halogenated hydrocarbons such as trichloroethane; chlorobenzene, o-dichlorobenzene, 1,2,
Aromatic halogenated hydrocarbons such as 4-trichlorobenzene; Esters such as ethyl acetate, butyl acetate and ethyl butyrate; Ethers such as ethyl ether, butyl ether, hexyl ether, octyl ether, anisole, ethoxybenzene, tetrahydrofuran and dioxane Hydrocarbon compounds such as pentane, hexane, heptane, octane, cyclohexane, benzene, toluene and xylene, and the like. These organic solvents can be used alone, of course, but by combining two or more kinds, the solubility of water and amino acid-N
It is possible to obtain an organic solvent in which important properties such as solubility of CA are preferably adjusted. The ratio of the amino acid-NCA to water and / or the organic solvent used as the polymerization reaction medium is 1: 0.5 to 1: 100, preferably 1 in the weight ratio of the amino acid-NCA: water and / or the organic solvent. : 1
~ 1:50.

The polymerization initiator is not particularly limited as long as it is a compound capable of causing the polymerization reaction of amino acid-NCA. Specific examples thereof include (a) primary amines such as methylamine, ethylamine, isopropylamine, butylamine, hexylamine, heptylamine, octylamine, (b) dimethylamine, diethylamine, dibutylamine, dihexylamine, diheptyl. Secondary amines such as amines and dioctylamines, (c) tertiary amines such as trimethylamine, triethylamine, tributylamine, trihexylamine, triheptylamine, trioctylamine, (d) ethanolamine, diethanolamine, triethanolamine , Alcohol amines such as N, N-dimethylethanolamine, and polyamines such as (e) ethylenediamine, hexamethylenediamine, N, N-dimethyl-1,3-propanediamine and triethylenediamine. Emissions such, others. These polymerization initiators can be used alone or in combination of two or more kinds.

The ratio of the polymerization initiator used is amino acid-NC.
It is 1/2 to 1/5000 mol, preferably 1/5 to 1/1000 mol, relative to 1 mol of A. By adjusting the amount of the polymerization initiator used within this range, poly-α-amino acid particles having a desired size can be obtained. In the present invention, the emulsifier is not particularly limited as long as it does not inhibit the amino acid-NCA polymerization reaction used, but nonionic emulsifiers and anionic emulsifiers are particularly preferable. Specific examples of the nonionic emulsifier include polyoxyethylene alkyl ether, polyoxyethylene alkylphenol ether,
Polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene fatty acid ester, polyethylene glycol alkyl ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester,
Examples thereof include glycerin fatty acid ester. Specific examples of the anionic emulsifier include a fatty acid salt, an alkyl sulfate ester salt, an alkylbenzene sulfonate, a dialkyl sulfosuccinate ester salt, an alkyl phosphate ester salt, a naphthalene sulfonate formalin condensate, and a polyoxyethylene alkyl sulfate ester salt. Can be mentioned.
These emulsifiers can be used alone or in combination of two or more kinds.

The emulsifier is used in an amount of 0.1 to 100 parts by weight, preferably 1 to 50 parts by weight, based on 1 part by weight of amino acid-NCA used. If the proportion of the emulsifier used is less than 0.1 part by weight, the polymer particles produced may not have a sufficiently large molecular weight. In the present invention, the order of adding the polymerization initiator, the emulsifier and the amino acid-NCA is not limited as long as the amino acid-NCA can be stably dispersed by the emulsifier. That is, in the present invention, it is necessary to emulsify the amino acid-NCA before the amino acid-NCA is hydrolyzed. Specifically, it is preferable to add the above-mentioned amino acid-NCA to water containing a polymerization initiator and an emulsifier to perform polymerization. At this time, it is preferable to stir the water in the reactor, and therefore, a mechanical stirring means or a means by ultrasonic irradiation can be used, and they may be used in combination. According to such a method, the monomer amino acid-NCA
In the polymerization reaction medium consisting of water to which is added, since the conditions necessary for the immediate polymerization of the amino acid-NCA as it is are satisfied, the amino acid-NCA is
At the same time that A is added, a polymerization reaction is generated from the surface thereof, but since this polymerization reaction is preferentially performed over the hydrolysis reaction, the polymerization reaction is not hindered by the hydrolysis reaction. Polymer particles of useful poly-α-amino acid are produced, and as a result, the polymerization reaction system becomes an emulsion of the polymer particles of poly-α-amino acid as it is.

The amino acid-NCA polymerization reaction occurs spontaneously when the amino acid-NCA contacts a polymerization initiator in water. The polymerization temperature depends on the type of amino acid-NCA,
Although it varies depending on the type of the polymerization initiator, it is usually 0 to 10
It is 0 ° C, preferably 5 to 90 ° C. By controlling the polymerization temperature, it is possible to produce poly-α-amino acid polymer particles having a desired molecular weight. The polymerization pressure is not particularly limited. During the polymerization reaction, it is necessary to stir the system to maintain the emulsified state. This stirring is preferably carried out, for example, by means of mechanical stirring in a reactor, and the number of rotations thereof is usually 20 to 3000 rpm. p. m. It is. It is preferable to perform an organic solvent removal treatment on the emulsion in the state in which the above-mentioned amino acid-NCA polymerization reaction is completed by a steam stripping method, a vacuum distillation method or the like, if necessary. Acidic amino acid-N is used to produce poly-α-amino acid particles.
Acidic poly-α-amino acid particles can be obtained by a method such as re-emulsification of CA after solution polymerization and pulverization of acidic polyamino acid bulk, but the above-mentioned emulsion polymerization method is preferable in view of cost.

As means for separating the polymer particles in the emulsion from water, means for evaporating water all at once using a spray dryer or the like, and centrifugal separation treatment of the emulsion to settle and separate the ultraviolet ray preventing particle particles are carried out. And means for drying the resulting solid,
Means for drying the solid after concentrating the emulsion using a water separation membrane and the like can be mentioned. If necessary, the polymer particles can be washed with water and / or an organic solvent to remove the emulsifier and be purified.

Acidic poly-α-obtained by the above method
The amino acid particles are preferably hydrolyzed to convert the ester group into a carboxy group. The hydrolysis treatment can be performed by a known method in the presence of an alkali or an acid. In addition, when the carboxy group and the amino group are reacted, a known dehydration condensation agent such as dicyclohexylcarbodiimide (DCC) is used, or the carboxy group existing in the poly-α-amino acid is chemically activated to cause the reaction. The activity can be increased.

Here, examples of the method for chemically activating the carboxy group include a method of forming an acid chloride and an active esterification with succinimide and the like.

Specific examples of the organic solvent used for immobilizing the ultraviolet ray inhibitor on the poly-α-amino acid include poly-
The same aliphatic halogenated hydrocarbons, aromatic halogenated hydrocarbons, esters, ethers, hydrocarbon compounds, and acetonitrile, dimethylformamide, dimethyl sulfoxide, etc., which are used in the polymerization of α-amino acids, It can be illustrated. The condensation reaction at the time of immobilizing the anti-UV agent on the poly-α-amino acid can be achieved by a known method, but it is usually under stirring at −80.
It is completed by reacting at + 80 ° C for 0.05 to 24 hours. The solution or suspension obtained by the above reaction is directly filtered, purified and then dried, or the solution is re-emulsified by a known method, and then solvent removal, purification and drying are carried out to prevent ultraviolet rays of the present invention. Particles are obtained.

The particles obtained by chemically immobilizing the ultraviolet ray inhibitor on the poly-α-amino acid obtained as described above are reacted with alcohol amines such as ethanolamine, propanolamine and butanolamine to give hydrophilicity on the particle surface. Can be converted. Further, the shell portion composed of poly-α-amino acid, diamines such as ethylenediamine, propylenediamine, hexamethylenediamine, octamethylenediamine, glycols such as ethylene glycol and propylene glycol, or malonic acid, succinic acid, adipic acid, etc. Crosslinking can be performed by reacting with dicarboxylic acids.

The poly-α obtained by the above method
-Poly-α-having no UV inhibitor on the surface of the particles by emulsion-polymerizing the amino acid-NCA with the particles obtained by chemically fixing the UV light on the amino acid as a seed.
It is also possible to form a layer of amino acids. The anti-ultraviolet particles of the present invention can be blended with raw materials and used as cosmetics.

[0018]

EXAMPLES Examples of the present invention will be described in detail below, but the present invention is not limited to these examples. The average particle size of the polymer particles in the following examples is measured by observing with a transmission electron microscope, and the CV value of the polymer particles shows a value calculated from the formula represented by the following mathematical formula 1.

[0019]

[Equation 1]

Example 1 2 liters of purified water was placed in a round bottom separable flask, and 1 g of an emulsifier (polyoxyethylene sorbitan monolaurate "Tween 20" (manufactured by Kao Corporation) was added thereto and mixed well. After emulsification, 14.4 mmol of triethylamine was added and stirred, and 100 g of powder of γ-benzyl-L-glutamate-N-carbonic anhydride (hereinafter referred to as “BLG-NCA”) was added to this emulsion.
(380 mmol) was added, and BLG-NCA was polymerized at room temperature for 5 hours while continuing stirring to give poly-γ.
An aqueous dispersion of -benzyl-L-glutamate (hereinafter referred to as "PBLG") particles was obtained. PB produced after the reaction
LG particles were separated by filtration, washed with water and filtered twice and dried. Disperse 50 g of the above PBLG particles in a solution prepared by dissolving 10 g of sodium hydroxide in 100 g of water,
The mixture was stirred at 60 ° C for 5 hours. The obtained dispersion was acidified with hydrochloric acid, filtered, washed with water, and the obtained particles were dried. 30 g of the thus obtained acidic polyamino acid particles, 500 ml of acetonitrile, and 5 g of 2-ethylhexyl-p-dimethylaminobenzoate were added to and dispersed in a separable flask, then 10 g of dicyclohexylcarbodiimide was gradually added, and the mixture was cooled with ice. Stir for 4 hours. The obtained particles were washed with water and dried to obtain ultraviolet ray-preventing particles having an average particle diameter of 10 μm and a CV value of 19%.

Example 2 By following the same procedure as in Example 1 except that 100 g (500 mmol) of γ-ethyl-L-glutamate-N-carbonic anhydride was used in place of BLG-NCA.
UV protection agent is chemically immobilized average particle size 9μ
m, CV value 19% poly-γ-ethyl-L-glutamate particles were obtained. Example 3 UV protection having an average particle size of 10 μm and a CV value of 19% in which the UV protection agent was chemically immobilized was prepared by the same method as in Example 1 except that the UV protection agent was changed to glyceryl-p-aminobenzoate. Particles were obtained. Test Example 1 In addition, as a result of performing a patch test by a strip method with respect to the ultraviolet ray-proof particles obtained in Examples 1 to 3, the above-mentioned was not observed in both the 24-hour patching test and the 48-hour patching test.

Test Example 2 The UV-resistant particles obtained in Examples 1 to 3 were blended according to the following prescription 1 to produce a powder foundation. The powder foundation produced as described above had a more lustrous gloss than the foundation produced without using the UV-preventing particles of the present invention, had good makeup paste, and showed almost no irritation to the skin.

[0024]

INDUSTRIAL APPLICABILITY In the UV-preventing particles of the present invention, the UV-preventing agent is chemically immobilized on poly-α-amino acid particles having excellent biocompatibility. Therefore, even if the particles come into contact with the oily base material, the oily base material hardly penetrates into the core portion containing the ultraviolet protection agent, and thus the ultraviolet protection agent is not substantially eluted to the outside of the particle and biocompatible. Excel. Therefore, the cosmetics containing the ultraviolet protective particles of the present invention cause less skin irritation. In addition, since the polyamino acid has high transparency, and further, since the UV protective agent is uniformly dispersed in the core portion, it is not necessary to add more than necessary, and it is possible to suppress whitening and coloring due to the UV protective agent. it can.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshitaka Yamakawa 2-11-24 Tsukiji, Chuo-ku, Tokyo Within Nippon Synthetic Rubber Co., Ltd. (72) Inventor Kyoko Kuroda 2-11-24 Tsukiji, Chuo-ku, Tokyo Within Nippon Synthetic Rubber Co., Ltd.

Claims (1)

[Claims] 1. A poly-polymer chemically bonded with an anti-UV agent.
Anti-UV particles comprising α-amino acid.