JP2008001774A - Ultraviolet light absorber and its use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve limitation of the application of an organic ultraviolet absorber due to the problems of gradual decomposition of the absorber itself by ultraviolet light and low heat-resistance. <P>SOLUTION: An anionic benzophenone-type organic ultraviolet absorber is chemically bonded to the interlayer of a hydrotalcite structure to form an inorganic-organic composite in which an organic substance is guarded by an inorganic substance. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an organic / inorganic composite ultraviolet absorber excellent in ultraviolet resistance, heat resistance and transparency.

Examples of the ultraviolet absorber include inorganic ultraviolet absorbers such as titanium oxide and zinc oxide, and organic ultraviolet absorbers such as benzotriazole and benzophenone. Inorganic systems have excellent UV resistance and heat resistance, but UV absorption and transparency, especially transparency, are inferior to those of organic systems, have photocatalytic activity, and adversely affect human skin and resins. On the other hand, the organic system is excellent in UV absorption and transparency, but has poor UV resistance and heat resistance, particularly UV resistance, and is rarely used in sunscreen cosmetics.
None

  Provided is an ultraviolet absorber having all of ultraviolet absorption, transparency, ultraviolet resistance and heat resistance and having no photocatalytic activity.

  The present invention provides the following formula (1)

（但し、式中、Ｍ^２＋はＭｇおよび／またはＺｎを、Ｍ^３＋は３価金属、好ましくはＡｌを、Ｂは２−ヒドロキシ−４−メトキシベンゾフェノン−５−スルホン酸イオン、Ａ^ｎ−はｎ価のアニオンをそれぞれ示し、ｘ，ｙおよびｍはそれぞれ次の範囲にある。０＜ｘ＜０．５、好ましくは０．２＜ｘ＜０．４，０≦ｙ＜０．２、好ましくは０≦ｙ＜０．１，ｘ＞ｙ，０≦ｍ＜４）で表されるハイドロタルサイト類を有効成分として含有する紫外線吸収剤を提供する。

^(Wherein the ^{M 2+} is Mg and / or ^{Zn, M 3+} is a trivalent metal, preferably Al, B is 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid ^{ion, A n-is} n Each of x, y and m are in the following ranges: 0 <x <0.5, preferably 0.2 <x <0.4, 0 ≦ y <0.2, preferably An ultraviolet absorber containing hydrotalcites represented by 0 ≦ y <0.1, x> y, 0 ≦ m <4) as an active ingredient is provided.

  Furthermore, this invention provides the sunscreen cosmetics which contain the hydrotalcite represented by Formula (1) as an active ingredient.

  The present invention further provides an ultraviolet-resistant resin composition and a resin packaging material containing the hydrotalcite represented by the formula (1) as an active ingredient.

  The ultraviolet absorber of the present invention exhibits a transparency equal to or higher than that of an ultraviolet absorber close to a benzophenone ultraviolet absorber in a film containing 1% by weight of polyethylene. Furthermore, as UV resistance, UV absorption hardly changes even when irradiated for 24 hours. By thermal analysis, the benzophenone system starts to decompose at about 180 ° C., whereas the ultraviolet absorber of the present invention starts to decompose at 300 ° C., which is about 120 ° C. higher. In addition, titanium oxide and zinc oxide decompose oil adsorbed on them by ultraviolet irradiation, whereas the ultraviolet absorbent of the present invention does not exhibit oil decomposing activity, and therefore does not exhibit photocatalytic activity. It is safe against other skin.

  The ultraviolet absorber of the present invention has the following formula (2)

（但し、式中、Ｍ^２＋は２価金属、Ｍ^３＋は３価金属、Ａ^ｎ−はｎ価のアニオンをそれぞれ示し、ｘおよびｍは式（１）と同じ範囲にある）で表される層状構造をしているハイドロタルサイト類の層間アニオンＡ^ｎ−の一部または全部をベンゾフェノン系紫外線吸収剤である２−ヒドロキシ−４−メトキシベンゾフェノン−５−スルホン酸イオンで置換した構造をしている。

(However, shown in the ^{formula, M 2+} is a divalent ^{metal, M 3+} is a trivalent ^{metal, A n-n-valent} anion, respectively, x and m are in the same range as the formula (1)) represented by and hydrotalcite substituted structure with an interlayer anion a ^n- in some or benzophenone UV absorber all 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid ion, which has a layered structure Yes.

In order to protect the high transparency and non-toxicity to low toxicity characteristic of the ultraviolet absorber of the present invention, M ²⁺ is preferably Mg and / or Zn, and M ³⁺ is preferably Al and / or Fe, particularly Al. As the amount x of M ³⁺ increases, the amount of B ⁻ that contributes to ultraviolet absorption increases.

In order that the ultraviolet absorber represented by the formula (1) of the present invention may have higher transparency, it is preferable to reduce the primary particles and suppress the aggregation of the secondary particles. On the other hand, in order to improve elongation as a sunscreen cosmetic or when used in a resin, it is preferable that the primary particles are large to some extent. From this demand, BET specific surface area of 5 to 40 m ² / g, average secondary particle diameter thereof at an accumulation of 50% is preferably in the range of 0.1-2 .mu.m, respectively particularly 9~25m ² / g, 0. A range of 1-1 μm is preferred.

  The ultraviolet absorber of the present invention can be used as it is, but for use in addition to sunscreen cosmetics or resins, an anionic surfactant such as a higher fatty acid, an alkali metal salt of a higher fatty acid, a phosphate ester, It is preferable to use after surface treatment with a silane, titanate or aluminum coupling agent. In particular, phosphate esters (including fluorine-containing phosphate esters) are preferable. Examples of these surface treatment agents include higher fatty acids such as lauric acid and stearic acid, alkali metal salts of higher fatty acids such as sodium laurate and sodium stearate, phosphate esters such as stearyl acid phosphate and oleyl acid phosphate, Coupling agents such as γ-methacryloxypropyltrimethoxysilane of vinyltriethoxysilane, isopropyltriisostearoyl titanate, acetoalkoxyaluminum diisopropionate and the like can be mentioned. The surface treatment can be performed by a method known per se. For example, the surface treatment agent is added to a slurry of water or alcohol medium of the compound of formula (1) in a liquid or emulsion form dissolved or diluted in water or alcohol with stirring, and mixed uniformly. Alternatively, the surface treatment agent liquid or emulsion is added to the powder of the compound of formula (1) under high-speed stirring with a Henschel mixer or the like, and mixed uniformly with heating or non-heating. The addition amount of the surface treatment agent is 0.1 to 10% by weight, preferably 1 to 5% by weight, based on the weight of the compound of formula (1) of the present invention.

Preparation of the ultraviolet absorbent of the present invention, an interlayer anion A ^n- is a monovalent anion A in formula (2) ^- prepared hydrotalcite is a conventional known method, the alkali metal salt solution of this B Can be produced by ion exchange. Ion exchange, A ^- to equivalent or more, preferably performed using 2 to 4 times equivalents of class B alkali metal salt aqueous solution. As A ⁻ , the larger the ion radius, the more easily ion exchange is performed. Specific examples include NO ₃ ⁻ , ClO ₄ ⁻ , HCOO ⁻ , and CH ₃ COO ⁻ .

In the formula ^(2), the production of ^{A n-} is a monovalent hydrotalcites There are two, for example, ^{A n-} is the case of NO _3, it will be described in detail. The first method involves co-precipitation of a mixed aqueous solution of Mg and / or Zn nitrate and aluminum nitrate and an aqueous sodium hydroxide solution while maintaining the pH at about 9 or higher, and then the steps of filtration, washing with water, drying and grinding are performed. It can manufacture by selecting suitably and using. The second method can be prepared by A ^n- is using hydrotalcite CO ₃ is ^2-, causes the CO ₃ ^2- in the mixed reaction under stirring and equivalent or more of nitric acid solution.

  In order to improve the transparency of the ultraviolet absorber of the present invention, the dispersibility in the resin, and the elongation as a sunscreen cosmetic, the hydrotalcite prior to ion exchange with an alkali metal salt of B is 120 ° C. Hydrothermal treatment is preferably performed at ˜200 ° C. for 10 to 20 hours.

  Examples of the ultraviolet absorber of the present invention include silicone oil, higher alcohol, lanolin glycerol stearate, cocoa butter, sorbitan sesquiolate, propylene glycol, mineral oil, isopropyl myristate, petrolactam, acrylic acid polymer, ethanol, water, and these It can be dispersed in a liquid carrier such as a mixture and used as a sunscreen cosmetic. As a sunscreen cosmetic, the transparency and photocatalytic activity, which are the disadvantages of the currently mainstream particulate zinc oxide and titanium oxide, can be eliminated.

  The ultraviolet absorbent according to the present invention is added to, dispersed or applied to a resin film such as a food material such as polyethylene, polypropylene, polyvinyl chloride, nylon, polyester, polyvinyl alcohol, etc. Deterioration, coloring, freshness reduction, etc. can be prevented. The film necessarily contains a heat-sealable resin and can be used by laminating one or two or more different resin films. Moreover, the bad influence by ultraviolet rays of various rubber | gum and resin itself can be reduced. It is 0.001-10 weight part with respect to 100 weight part of rubber | gum and / or resin of this invention ultraviolet absorber, Preferably it is 0.01-5 weight part.

  Hereinafter, the present invention will be specifically described based on examples.

And [Comparative Example 1] Commercially available hydrotalcite powder _{(composition: Mg 4.5 Al 2 (OH)} 13 CO 3 · 3.5H 2 O, BET specific surface area = ^12m 2 / g, cumulative 50% average secondary Disperse 500 g of particle size = 0.4 μm in about 4 liters (about 35 ° C.) of water with a chemistor, and gradually add 4 liters (about 35 ° C.) of 0.7 mol / liter HNO ₃ aqueous solution with stirring. Added. After heating this slurry to about 70 ° C., about 5 liters of an aqueous solution (about 70 ° C.) in which 4 mol of 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid soda was dissolved was added with stirring, and the reaction was continued for about 20 minutes. I let you. Thereafter, a solution obtained by dissolving 20 g of stearyl acid phosphate in 300 ml of isopropyl alcohol by heating (about 60 ° C.) was added for surface treatment. Thereafter, filtration, washing with water, drying and pulverization were performed. The XRD measurement result of the pulverized product was a diffraction pattern considered to be hydrotalcite with an expanded interlayer, and was the strongest peak d ₀₀₃ = about 20.8 mm. No diffraction of 7.6 mm and 9.0 mm corresponding to d ₀₀₃ of CO ₃ type and NO ₃ type hydrotalcite was detected, and therefore almost no CO ₃ type and NO ₃ type hydrotalcite remained. This indicates that the unit layer thickness in the layered structure has increased from about 7.6 mm of the CO ₃ type to about 20.8 mm with B ions entering instead of CO ₃ . BET specific surface area measured by liquid nitrogen adsorption method = 15 m ² / g, put in ethanol and subjected to ultrasonic wave for 5 minutes, then average secondary particle diameter of 50% cumulative obtained from particle size distribution measured by laser diffraction method = It was 0.4 μm.

Chelate titration of Mg and Al, NO ₃ absorption spectrophotometry, TOC measurement of organic substances, and measurement of the amount of water of crystallization by TG-DTA were as follows. Mg _4.5 Al ₂ (OH) ₁₃ (B ⁻ ) _1.99 (NO ₃ ) _0.01 · 2H ₂ O

  Table 1 shows the results obtained by measuring TG-DTA of the above-described ultraviolet absorber and B acid type trihydrate [Comparative Example 1] and evaluating the thermal decomposition rate of heat resistance.

  Since the weight loss at 100 to 150 ° C. is due to crystallization water, the weight loss due to the structural breakage of B is 150 ° C. or more. Therefore, when the weight loss between 150 to 300 ° C. is compared, the weight loss of the ultraviolet absorber of the present invention is 5.5%, whereas B is 51.6%. B is greatly improved in thermal stability according to the present invention. Considering that the processing temperature of the resin is about 200 to 300 ° C., B decomposes by 50% or more by 300 ° C. and its use is limited, whereas the ultraviolet absorber of the present invention is only about 5%. Since it does not decompose, the range of use can be extended to many resins.

In order to investigate the ultraviolet decomposition resistance of the ultraviolet absorbent of the present invention, about 1 g of a powder sample was placed in a watch glass, irradiated with ultraviolet rays having an intensity of 0.4 mw / cm ² for 7 hours, and the change in weight was measured. The result is shown in FIG.

  As a result of the above, it is shown that B is decomposed by ultraviolet irradiation and the weight is decreased, whereas the ultraviolet absorbent according to the present invention is hardly decomposed by a slight increase in weight.

  Next, in order to examine the ultraviolet absorptivity and transparency, the ultraviolet absorber of the present invention and the acid anhydride of B, commercially available ultrafine titanium oxide [Comparative Example 2], and zinc oxide [Comparative Example 3] After mixing 1 part by weight with respect to 100 parts by weight of each linear low density polyethylene, it was melt-kneaded at about 190 ° C. using an open roll, and then formed into a sheet having a thickness of 0.3 mm using a press molding machine. Using this sheet, the light transmittance in the wavelength range of 250 to 500 nm was measured. The results are shown in Table 2.

  Table 2 shows the following. The ultraviolet absorber of the present invention exhibits the same transparency (visible light transmittance) and ultraviolet absorptivity as those of an organic system. Transparency is clearly superior to inorganic systems, and UV absorption is almost the same as inorganic systems.

A mixed aqueous solution of zinc oxide and aluminum nitrate (Zn ⁻ = 1.0 mol / liter, Al = 0.5 mol / liter) (about 30 ° C.) and a 3 mol / liter aqueous sodium hydroxide solution (about 30 ° C.), respectively Using a metering pump at a rate of about 100 ml / min, it was continuously fed into a reaction vessel having a volume of about 5 liters, and co-precipitated with stirring at a pH of about 7.5 to 7.8. The coprecipitate was washed with water, placed in an autoclave, and hydrothermally treated at 150 ° C. for 20 hours. 500 g of the resulting slurry in terms of dry matter was taken, heated to about 60 ° C. with stirring, 5 liters of 1 mol / liter B Na salt aqueous solution was added, and the mixture was further stirred at about 60 ° C. for 30 minutes. . Thereafter, filtration, washing with water, drying and pulverization were performed. The chemical composition and physical properties of this powder were as follows. CO ₂ was measured by the AGK CO ₂ measurement method. Chemical composition: Zn _0.67 Al _0.33 (OH) ₂ B ⁻ _0.31 (CO ₃ ) _0.01 · 1.8H ₂ O. BET specific surface area = 12 m ² / g, average secondary particle diameter of 50% cumulative = 0.3 μm. 100 g of the above powder was dispersed in about 400 ml of ethanol, 3 g of perfluoroalkyl phosphate diethanolamine salt was dispersed in 100 ml of ethanol, added, stirred for about 20 minutes, filtered, dried and pulverized. This was uniformly mixed with a high speed mixer with the following formulation to prepare a sunscreen cosmetic.
Ion exchange water 30% by weight
20% by weight of the present invention UV absorber
Branched polyether-modified silicon 1% by weight
1,3-butylene glycol 6% by weight
Capryl Methicone 5% by weight
Octamethylcyclotetrasiloxane 26% by weight
Octyl methoxycinnamate 9% by weight
Edetate 0.5% by weight
Ethanol 2.5% by weight
This cosmetic had very good growth on the skin.

It is the graph which showed the decomposability | degradability of the ultraviolet absorber by ultraviolet irradiation.

Claims (7)

Following formula (1)

^{(Wherein, M 2+} is Mg and / or ^{Zn, M 3+} is a trivalent metal such as Al, B is 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid ^{ion, A n-is} the n-valent X, y and m are respectively in the following ranges: 0 <x <0.5, 0 ≦ y <0.2, x> y, 0 ≦ m <4) An ultraviolet absorber containing sites as an active ingredient. The ultraviolet absorber according to claim 1, wherein the surface of the hydrotalcite of formula (1) is surface-treated with a phosphate ester anionic surfactant. The ultraviolet absorbent according to claim 1, wherein the 50% cumulative secondary particle size of the hydrotalcite of formula (1) is 1.0 µm or less and the BET specific surface area is 25 m ² / g or less. The ultraviolet absorber according to claim 1, wherein M ^{3+ in the} formula (1) is Al. In a liquid carrier such as silicone oil, higher alcohol, lanolin glycerol stearate, cocoa butter, sorbitan sesquiolate, propylene glycol, mineral oil, isopropyl myristate, petrolactam, acrylic acid polymer, ethanol, water, and mixtures thereof A sunscreen cosmetic characterized by dispersing an ultraviolet absorber of formula (1). A UV-resistant and / or UV-absorbing resin composition in which 0.01 to 20 parts by weight of the UV absorber represented by the formula (1) is blended with 100 parts by weight of a resin. A multilayer film obtained by laminating a single layer or two or more types of films in which a UV absorber represented by the formula (1) is dispersed or applied to a resin such as polyethylene, polypropylene, polyamide, polyester, polyvinyl alcohol, and ethylene vinyl acetate copolymer. UV-absorbing packaging material consisting of.

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