JP2958193B2 - Water-soluble UV absorber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ultraviolet absorber.
More specifically, the present invention relates to an ultraviolet absorber which can be suitably used for cosmetics such as hair and skin.

[0002]

2. Description of the Related Art The wavelength of sunlight falling on the ground is
Ultraviolet light having a wavelength of 290 to 400 nm has a particularly large energy, and is one of the causes of various chemical reactions such as fading and weakening of paints, dyes, and fibers, for example. It causes skin tanning, fine wrinkles, increased spots, and decreased skin elasticity, which causes damage such as skin aging.

[0003] In recent years, products containing various ultraviolet absorbers for preventing the above-mentioned obstacles caused by ultraviolet rays have been found in the fields of plastics, synthetic fibers, paints, medicines, cosmetics, and the like. Many products are being developed in the cosmetics field. UV absorbers used in these para aminobenzoate derivatives, salicylate derivatives, Baie benzophenone derivatives, cinnamate derivatives, dibenzoylmethane derivatives, and the like benzotriazole derivatives, most of which a low-molecular compound insoluble in water.

[0004] On the other hand, as seen in the fields of paints and cosmetics, the use of organic solvents and CFCs has been abolished in view of their harm to the human body and the pollution of the air. Aqueous coating agents and spray products mainly containing agents are increasing. However, since most of the ultraviolet absorbers are insoluble in water, a dispersant or the like, which is not originally required for the product, must be used in order to be incorporated into an aqueous product. In addition, even when blended in a product using a dispersant in this way, these ultraviolet absorbers separate when the product is stored for a long period of time, or the absorbent elutes during use of the product. There is a problem.
For these reasons, development of an ultraviolet absorber that is dispersed or dissolved in water and hardly dissolves during use has been desired.

As described above, the use of an ultraviolet absorbent in an aqueous solvent has been actively studied in the fields of medicine and cosmetics. For example, as an ultraviolet absorbent, an alkyl ester of p-dimethylaminobenzoic acid and ethanol are used as an interface between ethanol and ethanol. Opaque cosmetic material containing an activator as an essential component (JP-A-61-9
No. 1112) and 2-ethylhexyl p-dimethylaminobenzoate and 4-tert-butyl-
Lotions obtained by blending 4'-methoxybenzoylmethane (JP-A-61-167613) are known.

However, since these ultraviolet absorbers are fat-soluble low molecular weight compounds, they must be incorporated in a large amount when used in aqueous cosmetics. Nevertheless, there is a problem that there is a limit in terms of solubility and the like.

Further, it is generally considered that a high molecular compound has lower skin irritation and percutaneous absorption than a low molecular compound, and a method of polymerizing an ultraviolet absorbent is being studied. From such a viewpoint, an ultraviolet absorbent copolymerization type non-film-forming resin emulsion has been proposed (JP-A-3-2202).
No. 13), an ultraviolet absorber that has been polymerized and emulsified and dispersed in an aqueous solvent has been developed.

However, the production of an emulsion requires special equipment and advanced technology, and the emulsion contains essentially a large amount of a low molecular compound such as a surfactant. Because of these problems, development of an ultraviolet absorber that can be produced with conventional simple stirring type polymerization reaction equipment and technology and has excellent dispersibility and solubility in water has been awaited.

[0009]

SUMMARY OF THE INVENTION Accordingly, the present inventors
In view of the prior art, exhibit excellent ultraviolet absorption,
Develop an ultraviolet absorber that does not precipitate even when stored in a water-based product for a long period of time and does not separate during use, and can be suitably used in, for example, cosmetics. As a result of intensive research, we finally found an ultraviolet absorber that was not only excellent in ultraviolet absorption, but also excellent in moisture retention, surface activity, etc.
The present invention has been completed.

[0010]

That is, the present invention provides one aspect of the present invention.
General formula (I):

Embedded image (In the formula, R ¹ is a hydrogen atom or a methyl group, and R ² is linear or
Or an alkylene group having 1 to 4 carbon atoms having a side chain, R ³ is
A hydrogen atom or an alkyl group having 1 to 4 carbon atoms, n is 1 to 30;
Monomer represented by the an integer) (A) (a hydrophilic or water soluble monomer (A)) and the general formula _{(II): CH 2 = CR} 4 -COO-R 5 -R 6 (II) ( wherein , R ⁴ is a hydrogen atom or a methyl group, and R ⁵ is
Or an alkylene group having 1 to 8 carbon atoms having a side chain, R ⁶ is
General formula:

Embedded image (Wherein, R ⁷ is a hydrogen atom or a methyl group, and R ⁸ is a hydrogen atom
Or a methoxy group).
A monomer represented by you) (B) (a monomer having an ultraviolet absorbing group (B)) as an essential copolymerization component, a hydrophilic solvent
A copolymer that is E copolymerized in medium regarding ultraviolet absorber.

[0011]

Function and Examples As described above, the ultraviolet absorber of the present invention is a copolymer containing a hydrophilic or water-soluble monomer (A) and a monomer (B) having an ultraviolet absorbing group as essential copolymer components. It consists of

The monomer (A) used in the present invention is a monomer exhibiting hydrophilicity or water solubility, and is used in combination with the monomer (B) which imparts water solubility to the ultraviolet absorbent of the present invention and has an ultraviolet absorbing group. By doing so, it shows good solubility in water.

The term "water-soluble" as used herein means a compound
When 10 g or more is dispersed or dissolved in 100 g of water and left at room temperature for 24 hours, the compound does not precipitate or separate into two layers.

Representative examples of the monomer (A) include, for example, the following general formula (I):

[0015]

Embedded image

(Wherein R ¹ is a hydrogen atom or a methyl group,
R ² is a linear or branched alkylene group having 1 to 4 carbon atoms, and R ³ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
And n represents an integer of 1 to 30).

In the general formula (I), n is 1 to
It is an integer of 30, and it is possible to adjust the water solubility, film forming property and adhesiveness of the ultraviolet absorber obtained by the value of n. When the n is greater than 30, the steric hindrance of such a monomer becomes large, and it becomes difficult to perform uniform copolymerization.Therefore, the water solubility of the obtained ultraviolet absorber tends to decrease, When n is 0, the water solubility of the ultraviolet absorbent may be insufficient. In the present invention, n is preferably an integer of 2 to 25.

Specific examples of the monomer (A) represented by the general formula (I) include, for example, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate , Polyethylene glycol mono (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, polypropylene glycol mono (meth) acrylate, and the like. Such monomers may be used alone or in combination of two or more. Although it can be used, methoxyethyl (meth) acrylate, hydroxyethyl (meth) acrylate, and the like in that high water solubility can be imparted to the ultraviolet absorber obtained among these. Polyethylene glycol mono (meth) acrylate and methoxypolyethylene glycol (meth) acrylate are preferred.

The amount of the monomer (A) used is 60 to 99.5% (% by weight, hereinafter the same) of the total amount of the copolymer components, preferably
It is desirable to adjust so as to be 62 to 99%. When the amount of the monomer (A) used is less than 60%,
The water solubility of the resulting UV absorber tends to decrease, and if it exceeds 99.5%, the amount of the monomer having a UV absorbing group relatively decreases,
UV absorption tends to decrease.

The monomer (B) used in the present invention is a monomer exhibiting ultraviolet absorbing properties, and imparts ultraviolet absorbing properties to the ultraviolet absorbing agent of the present invention.

Representative examples of the monomer (B) include, for example, a compound represented by the following general formula (II): CH ₂ ＣＲCR ⁴ —COO—R ⁵ —R ⁶ (II) (wherein R ⁴ is a hydrogen atom or a methyl group; R ⁵ is a linear or branched alkylene group having 1 to 8 carbon atoms, and R ⁶ is
General formula:

Embedded image (Wherein, R ⁷ is a hydrogen atom or a methyl group, and R ⁸ is a hydrogen atom
Or a methoxy group) .

In the general formula (II), R ⁵ is a linear or branched alkylene group having 1 to 8 carbon atoms, which enhances the water solubility of the ultraviolet absorber obtained therefrom. In view of this, a straight-chain one having 1 to 4 carbon atoms is preferable.

Examples of the monomer represented by the general formula (II) include carboxylic acids which exhibit ultraviolet absorption, such as o-aminobenzoic acid, p-aminobenzoic acid, o-N, N-dimethylaminobenzoic acid, and p-aminobenzoic acid. N, N-dimethylaminobenzoic acid, cinnamic acid or p- methoxy and cinnamic acid, arsenate Doroki <br/> Shiechiru (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxypentyl ( Meth) acrylates,
Hydroxyhexyl (meth) acrylate, hydroxy heptyl (meth) acrylate, esters of hydroxyalkyl (meth) acrylate bets such as hydroxy octyl (meth) acrylate. Specific examples of such monomers, for example, o-N, N -Dimethylaminobenzoic acid (meth) acryloyloxyethyl, p-
N, N-dimethylamino (meth) acryloyloxyethyl benzoate, p-methoxycinnamate (meth) acryloyloxyethyl, cinnamate (meth) acryloyloxyethyl
Etc. Le, and the like. In addition, such a monomer can be used alone or as a mixture of two or more kinds. Among them, the ultraviolet absorption wavelength region is preferable and a wide range,
In addition, p-
(Meth) acryloyloxyethyl N, N-dimethylaminobenzoate and (meth) acryloyloxyethyl p-methoxycinnamate are preferred.

The amount of the monomer (B) used is desirably adjusted so as to be 0.5 to 40%, preferably 1 to 38% of the total amount of the copolymer components. When the amount of the monomer (B) used is less than 0.5%, the ultraviolet absorbing ability of the monomer (B) tends to be insufficient, and when the amount exceeds 40%, the amount of the monomer (B) increases. The water solubility of the resulting UV absorber tends to decrease.

The monomer (C) used in the present invention is a monomer copolymerizable with the monomer (A) and the monomer (B), and includes, for example, a film-forming property, a water-soluble property, a foaming property, an adhesive property and an adhesive property. It is used to appropriately adjust physical properties such as the above and to improve copolymerizability of the monomer (A) and the monomer (B).

Specific examples of the monomer (C) include (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and cyclohexyl (meth) acrylate. , 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate,
Lauryl (meth) acrylate, tridecyl (meth) acrylate, (meth) acrylamide, diacetone (meth) acrylamide, N- (meth) acryloyloxyethyl-N, N, N-trimethylammonium chloride, N- (meth) acryl Leuroxyethyl-N-benzyl-N, N-dimethylammonium chloride and the like. Such monomers (C) is Ru can be used alone or in admixture of two or more.

The amount of the monomer (C) used is desirably 20% or less, preferably 5 to 15% of the total amount of the copolymer components. When the amount of the monomer (C) exceeds 20%, the water solubility of the obtained ultraviolet absorbent tends to decrease.

The ultraviolet absorbent of the present invention is obtained by adjusting the desired amount of the monomers (A) to (C) and copolymerizing the same in a hydrophilic organic solvent.

Here, the hydrophilic organic solvent is an organic solvent having a solubility in water of 10 g / 100 g of water (25 ° C.) or more. Specific examples of such a hydrophilic organic solvent include, for example, aliphatic C1-4 alcohols having 1 to 4 carbon atoms, ethyl cellosolve, butyl cellosolve, dioxane, methyl acetate, dimethylformaldehyde and the like. -Dihydric alcohols are particularly preferred in handling.

Specific examples of the above-mentioned monohydric alcohol include, for example, methanol, ethanol, isopropanol and the like. Specific examples of the dihydric alcohol include:
For example, propylene glycol and the like can be mentioned.

When the ultraviolet absorbent of the present invention is used in cosmetics, ethanol and isopropanol are particularly preferable among the above-mentioned hydrophilic organic solvents in consideration of their safety.

The above-mentioned copolymerization reaction is carried out with monomers (A) to
This is carried out by dissolving (C) in the hydrophilic organic solvent, adding a polymerization initiator, and stirring while heating under an inert gas stream such as nitrogen gas.

The polymerization initiator is not particularly limited as long as it is generally used in a solution polymerization method. Specific examples thereof include benzoyl peroxide (BP)
O), peroxides such as lauroyl peroxide, and azo compounds such as azobisisobutyronitrile (AIBN).

If any of the monomers (A), (B) and (C) contains a nitrogen atom,
When a peroxide is used as a polymerization initiator, an azo compound is preferably used because a side reaction other than polymerization may be a concern.

In the polymerization, the hydrophilic organic solvent is
It is preferable that the concentration of the copolymer component is adjusted to about 10 to 70% before use. When the concentration of the copolymer component exceeds 50%, the polymerization is carried out by dividing and gradually adding the copolymer component to avoid rapid generation of polymerization heat,
It is preferable for safe polymerization.

The polymerization temperature depends on the type of polymerization initiator used, and cannot be unconditionally determined. However, it is usually preferable to set the polymerization initiator at a temperature equal to or higher than the 10-hour half-life temperature of the polymerization initiator. It is preferable that the temperature is close to the reflux temperature of the organic solvent, since the polymerization with higher reproducibility can be carried out.

If the polymerization time is shorter than 8 hours, the polymerization may be incomplete and unreacted monomers may remain. Therefore, the polymerization time is set to 8 hours or more, preferably 12 to 36 hours. It is desirable.

It should be noted that whether or not the residual monomer exists is determined by
It can be performed by confirming whether or not a double bond exists by a general method, for example, the PSDB method.

The ultraviolet absorber of the present invention thus obtained preferably has a weight average molecular weight of about 1,000 to 100,000, preferably about 2,000 to 500,000, more preferably about 10,000 to 200,000. When the weight average molecular weight is less than 1000, there is a risk of percutaneous absorption, and the safety to the human body tends to be deteriorated.When the weight average molecular weight exceeds 1,000,000, it becomes solid grease. Water solubility tends to decrease.

The ultraviolet absorber of the present invention can be used usually as it is or after removing the solvent.

The ultraviolet absorbent of the present invention has excellent ultraviolet absorbability and can be suitably used, for example, in cosmetics.

The ultraviolet absorber of the present invention can be made into a liquid substance such as a lotion, a tonic, a lotion, an emulsion or the like by using, for example, glycerin, propylene glycol, vegetable oil, or the like as a base. By adding triethanolamine or the like to a base such as a cream emulsified, a cream can be used.

The ultraviolet absorbent of the present invention may contain a flavor, a coloring agent, an excipient, and the like, if necessary.

Next, the ultraviolet absorbent of the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

Production Example 1 In a 500 ml four-necked flask equipped with a reflux condenser, a thermometer, a charging tube and a stirrer, 50 parts of p-N, N-dimethylaminobenzoic acid (parts by weight, hereinafter the same), 43 parts of thionyl chloride and 200 parts of toluene were added, and the mixture was heated and refluxed at 100 to 108 ° C for 4 hours. At this time, the generated acidic gas was led from an end of the reflux cooling pipe to an alkali trap and captured. The reaction solution was cooled to room temperature, and a mixed solution of 39 parts of hydroxyethyl methacrylate and 1 part of hydroquinone as a polymerization inhibitor was added dropwise, followed by stirring at room temperature for 24 hours. After the reaction solution was washed with a 2N aqueous solution of sodium hydroxide and water, toluene was distilled off under reduced pressure. The concentrated residue was recrystallized from methanol to obtain a reaction product as white crystals.

The infrared absorption spectrum and proton nuclear magnetic resonance spectrum of the obtained reaction product were measured and analyzed. As a result, it was confirmed that the product was methacryloyloxyethyl pN, N-dimethylaminobenzoate. confirmed.

The melting point and ultraviolet absorption spectrum of the obtained product were measured according to the following methods.

(Melting point) Melting point measuring apparatus (manufactured by Mettler, F
As a result of measurement using P-61), it was 65 ° C.

(Ultraviolet absorption spectrum) Using an ultraviolet spectrophotometer (UV-240, manufactured by Shimadzu Corporation), the sample was measured as a solution having a concentration of 35 ppm with anhydrous ethanol in a quartz cell having an optical path difference of 10 mm. The result is shown in FIG.

From the measurement results, the ultraviolet absorption wavelength region and the maximum characteristic absorption wavelength of the obtained monomer (B) having an ultraviolet absorbing group were obtained. The ultraviolet absorption wavelength region was 260 to 340 nm, and the maximum characteristic absorption wavelength was 260 to 340 nm. The absorption wavelength was 310 nm.

Preparation Example 2 In Preparation Example 1, the charged composition was changed to p-methoxycinnamic acid.
A crude reaction product was obtained in the same manner as in Production Example 1, except that 36 parts, 29 parts of thionyl chloride, 100 parts of toluene, and 26 parts of hydroxyethyl methacrylate were used. This was purified by silica gel column chromatography to obtain a yellow oily reaction product.

The infrared absorption spectrum and proton nuclear magnetic resonance spectrum of the obtained reaction product were measured and analyzed. As a result, it was confirmed that the product was methacryloyloxyethyl p-methoxycinnamate.

The ultraviolet absorption spectrum of the obtained product was measured in the same manner as in Production Example 1. As a result, the spectrum was almost the same as that shown in FIG. 1. The ultraviolet absorption wavelength range of the monomer was 250 to 350 nm. , The maximum characteristic absorption wavelength is
308 nm.

Example 1 A 100 ml five-necked flask equipped with a reflux condenser, a thermometer, a nitrogen inlet tube, a charging tube, and a stirrer was charged with 45 parts of 2-methoxyethyl acrylate as a copolymer component.
-Hydroxyethyl acrylate 50 parts and p-N, N
-Methacryloyloxyethyl dimethylaminobenzoate 5
Parts, and 400 parts of absolute ethanol as a solvent,
To this, 2 parts of α, α'-azobisisobutyronitrile as a polymerization initiator was added, and the mixture was stirred at 80 ° C. under a nitrogen stream.
And heated to reflux. After refluxing for 6 hours, 0.25 parts of α, α'-azobisisobutyronitrile was added, and the mixture was refluxed for further 12 hours to complete the reaction.

Ethanol was distilled off from the obtained polymer solution using a concentrator until the resin solid content concentration became 50%, and an ultraviolet absorber (50% ethanol solution) was obtained. The weight average molecular weight of the resin solids contained in the solution was measured by gel permeation chromatography (hereinafter, referred to as GPC) to be 19100 (in terms of styrene).

Next, the appearance, water solubility, characteristic absorption wavelength and tactile sensation of the obtained ultraviolet absorber were examined according to the following methods. Table 2 shows the results.

(A) Appearance The appearance was visually observed.

(B) Water was added to a 50% aqueous ethanol solution at a liquid temperature of around 25 ° C. to determine whether the solution was diluted. The evaluation criteria are shown below.

(Evaluation Criteria) A: No turbidity occurs when diluted 10 times or more. B: No turbidity occurs when diluted 5 times or more. C: Turbidity occurs when diluted 5 times or more, but no aggregated precipitate is observed. D: When diluted 5 times or more, turbidity occurs, and coagulated precipitates are slightly observed. E: When diluted 5 times or more, turbidity occurs, and aggregate precipitates are clearly observed.

(C) Characteristic absorption wavelength Using a UV spectrophotometer (UV-240, manufactured by Shimadzu Corporation), the sample was used as a 100 ppm aqueous solution, and the UV absorption spectrum was measured in a quartz cell having an optical path difference of 10 mm. The absorption wavelength (nm) was examined.

(D) Tactile feel A 50% ethanol solution was uniformly applied on a glass plate so as to have a concentration of 20 g / m ² , air-dried at room temperature for 24 hours, and the feel of the surface was examined with a finger.

Examples 2 to 5 and 8 to 12 An ultraviolet absorber (50% ethanol solution) was obtained in the same manner as in Example 1 except that the copolymerized components blended were changed as shown in Table 1.

The results of GPC measurement of the weight average molecular weight of the resin solids contained in the solution are shown in Table 1.

Next, the physical properties of the obtained ultraviolet absorbent were examined in the same manner as in Example 1. Table 2 shows the results.

Examples 6 and 7 An ultraviolet absorber (50% ethanol) was used in the same manner as in Example 1 except that the blended copolymer components were changed as shown in Table 1 and the amount of anhydrous ethanol used was changed to 300 parts. Solution). Table 1 shows the results of measuring the weight average molecular weight of the resin solids contained in the solution by GPC.

Next, the physical properties of the obtained ultraviolet absorbent were examined in the same manner as in Example 1. Table 2 shows the results. FIG. 2 shows the measurement results of the ultraviolet absorption spectrum of the ultraviolet absorbent obtained in Example 6. The ultraviolet absorption spectra of the ultraviolet absorbents obtained in Examples 1 to 5 and 7 to 12 are almost the same as the spectra shown in FIG. 2, and have a wide ultraviolet absorption wavelength range of 250 to 350 nm. there were.

In the table, each abbreviation means the following.

MEA: 2-methoxyethyl acrylate HEA: 2-hydroxyethyl acrylate HEMA: 2-hydroxyethyl methacrylate M2GM: methoxydiethylene glycol methacrylate M4GM: methoxypolyethylene glycol methacrylate (n ≒ 4) M9GM: methoxypolyethylene glycol methacrylate (n ≒ 9) ) M23GM: methoxypolyethylene glycol methacrylate (n） 23) MEDB: p-N, N-dimethylamino methacryloxylethyl benzoate MEMC: p-methoxycinnamate methacrylyloxyethyl MMA: methyl methacrylate SMA: stearyl methacrylate TMA: tridecyl meth click relay preparative M A: methacrylic acid

[0069]

[Table 1]

[0070]

[Table 2]

From the results shown in Table 2, Example 1 of the present invention was obtained.
The ultraviolet absorber obtained in ~ 12 has a transparent to pale yellow appearance, is water-soluble, and has an ultraviolet characteristic absorption wavelength of 3 to 3.
It can be seen that it is around 10 nm.

Comparative Examples 1 to 5 The water solubility of a compound prepared by dissolving or decomposing only 50 parts of the compound exhibiting ultraviolet absorption shown in Table 3 in 50 parts of ethanol was examined in the same manner as in Example 1.

As a result, all of the compounds used in Comparative Examples 1 to 5 became turbid when water was added at a liquid temperature of about 25 ° C. and diluted 5 times or more, and aggregate precipitates were clearly observed. (Evaluation E of water solubility), and it could not be said that it exhibited water solubility.

[0074]

[Table 3]

Formulation Examples 1 to 12 14 g of stearic acid, 4 g of liquid paraffin and 10 g of the ultraviolet absorbent (50% ethanol solution) obtained in Examples 1 to 12 were heated to 75 ° C. in a water bath and mixed.

Next, 4 g of glycerin, 2 g of triethanolamine and 56 g of purified water were mixed and heated to 75 ° C. to form a uniform solution.

This solution was added to the above-mentioned mixed solution of stearic acid, liquid paraffin and an ultraviolet absorbent, mixed well with stirring, and cooled to room temperature to obtain a sunscreen.

After the obtained cream was stored at room temperature for one month, the condition was visually observed, and no change was observed in any of the creams.

Next, the sunscreen effect of the obtained cream was examined according to the following test methods. As a result, when the cream of the control was applied, the skin of the portion showed a red color close to red, whereas when the cream of Formulation Examples 1 to 12 was applied, the skin of the portion was red. The color showed little difference compared to the color of the unexposed part.

(Test Method) The creams of Formulation Examples 1 to 12 and the control cream (Preparation Examples 1 to 12 except that the ultraviolet absorbent of Examples 1 to 12 was not used) were applied to three places on the back of each of 15 panelists. Each of them was applied in a 5 x 5 cm square at a concentration of 2 mg / cm ^2, and the other parts were covered with a bleaching cloth and exposed to direct sunlight after 15 minutes (location: Osaka, time :
It was exposed for 2 hours at 1:00 pm in mid-August, weather: sunny.

The effect was judged visually one hour after the end of the exposure.

[0082]

The ultraviolet absorbent according to the present invention exhibits excellent ultraviolet absorptivity in a wide range of wavelengths and does not precipitate even when it is blended with an aqueous product and stored for a long period of time. Since there is no separation in the inside, there is an effect that it can be suitably used for, for example, cosmetics.

[Brief description of the drawings]

FIG. 1 is a graph showing an ultraviolet absorption spectrum of methacryloyloxyethyl pN, N-dimethylaminobenzoate obtained in Production Example 1.

FIG. 2 is a graph showing an ultraviolet absorption spectrum of the ultraviolet absorbent of the present invention obtained in Example 6.

──────────────────────────────────────────────────続 き Continuation of front page (51) Int.Cl. ⁶ identification code FI C08F 220/36 C08F 220/36 290/06 290/06 (58) Field surveyed (Int.Cl. ⁶ , DB name) C09K 3 / 00 104 A61K 7/42 C08F 220/00-220/70 C08F 290/00-290/14

Claims (4)

(57) [Claims] 1. A general formula (I): ## STR1 ## (In the formula, R ¹ is a hydrogen atom or a methyl group, and R ² is linear or
Or an alkylene group having 1 to 4 carbon atoms having a side chain, R ³ is
A hydrogen atom or an alkyl group having 1 to 4 carbon atoms, n is 1 to 30;
A) represented by the general formula (I):
Formula (II): CH ₂ ＣＲCR ⁴ —COO—R ⁵ —R ⁶ (II) (In the formula, R ⁴ is a hydrogen atom or a methyl group, and R ⁵ is a straight chain.
Or an alkylene group having 1 to 8 carbon atoms having a side chain, R ⁶ is
General formula: ## STR2 ## (Wherein, R ⁷ is a hydrogen atom or a methyl group, and R ⁸ is a hydrogen atom
Or a methoxy group).
It represented Ru monomer (B) and essential copolymerization component to)
And water-soluble ultraviolet absorbing agent comprising a copolymer that is E copolymerized with a hydrophilic solvent. 2. The water-soluble ultraviolet absorbent according to claim 1, wherein the copolymer comprises a copolymer component containing a monomer (C) copolymerizable with the monomer (A) and the monomer (B). Wherein monomer (A) 60-99.5 wt% and the monomer (B) 0.5 to 40% by weight of essential copolymerization component to a copolymer according to claim 1 or 2, wherein the water-soluble UV absorber . 4. The monomer water-soluble <br/> ultraviolet absorbent described 3 usage claim 2 or at most 20% by weight of the copolymer components total amount of (C).