JPH1046135A - Ultraviolet-intercepting agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an inorganic ultraviolet-intercepting agent highly able to intercept ultraviolet rays and excellent in transparency by using titanium phosphate microparticles having a specified means particle diameter. SOLUTION: This agent comprises a titanium phosphate having a means particle diameter of 0.1μm or below, desirably a compound having a Ti/P atomic ratio of 0.5-1.5. Especially, titanium phosphate having a Ti/P atomic ratio of 0.8-1.0 possesses an excellent ability to intercept ultraviolet rays and excellent transparency and therefore is a desirable compound. When the titanium phosphate has a Ti/P atomic ratio smaller than 0.5 or larger than 1.5, there is the possibility of lowering the ability to intercept ultraviolet rays. Desirable examples of the titanium phosphates include Ti(OH)PO4 , TiPO4 and Ti(HPO4 )2 . This agent is excellent in both the ability to intercept ultraviolet rays and transparency, so that it is used as, for example, a modifier for ultraviolet- intercepting coatings used for, e.g., windowpanes of a high-rise building or an automobile or also as a cosmetic additive because of its safety and good spread on the skin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultraviolet ray shielding agent comprising inorganic fine particles having high transparency and excellent ultraviolet ray shielding properties. Alternatively, it is useful as a modifier that imparts a function of preventing deterioration of a material or a molded body due to ultraviolet irradiation by coating the molded body.

[0002]

2. Description of the Related Art Generally, when a certain substance is irradiated with light, a part of the incident light is reflected or absorbed by the substance, and the other incident light is transmitted through the substance. The ultraviolet shielding property of a substance indicates the property that the substance has low ultraviolet transmittance. There are organic and inorganic UV shielding agents. In general, organic UV-shielding agents have high UV-absorbing properties and low UV-reflecting properties.
It is high in transparency to visible light (hereinafter simply referred to as transparency). The disadvantage is that the organic ultraviolet shielding agent is weak to heat and may be decomposed by adding an organic ultraviolet shielding agent to the resin or by heating during the subsequent resin processing (Japanese Patent Laid-Open No. 8-4124).
No. 4), a resin into which the organic ultraviolet shielding agent has been kneaded has a large change with time, and the ultraviolet shielding property is reduced due to bleed out of the organic ultraviolet shielding agent from the kneaded resin. In order to improve the above disadvantages, copolymers in which a characteristic group having an ultraviolet absorbing property is bonded have been proposed (JP-A-4-161415, JP-A-6-880).
No. 65), the improvement effect is still insufficient.

On the other hand, inorganic ultraviolet shielding agents generally have low ultraviolet absorption and high ultraviolet reflectance, are excellent in bleed-out resistance and heat resistance, are highly safe to skin, and are organic. It has the advantages that it is stable even when it comes in contact with a solvent and that it does not decompose even when irradiated with ultraviolet light, so that its ultraviolet shielding ability is maintained for a long time. However, inorganic ultraviolet shielding agents have low ultraviolet shielding properties compared to organic ultraviolet shielding agents. Therefore, in order to sufficiently exhibit ultraviolet shielding properties by blending with a resin, it is necessary to add a large amount to the resin. However, since conventional inorganic ultraviolet shielding agents have low transparency, if added in a large amount, there is a problem that the original color tone and transparency of the resin are greatly impaired.

As a technique for improving the transparency of an inorganic ultraviolet shielding agent, a method of dispersing an ultraviolet shielding agent using a zinc oxide having an average particle diameter of 0.05 μm or less (JP-A-6-297630) or a paint shaker. [Chemistry and Industry, 69
(8), 320-325, (1995)], but none of the improvement effects are sufficient.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an inorganic ultraviolet shielding agent having high transparency as well as ultraviolet shielding properties.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that fine particles of titanium phosphate are excellent in both ultraviolet shielding properties and transparency, and have completed the present invention. That is, the present invention is an ultraviolet ray shielding agent comprising titanium phosphate having an average particle size of 0.1 μm or less.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION

○ Titanium phosphate The titanium phosphate in the present invention is a compound in which the main component of the anionic component is a phosphate ion and the main component of the cation component is a titanium ion, and may have an ion-exchangeable proton or hydroxy ion. As long as the effects of the present invention are not impaired, these ion-exchangeable ions may have a cation or anion that can be ion-exchanged. Specific examples of cations that can be supported on titanium phosphate include alkali ions such as sodium ion and potassium ion and alkaline earth metal ions such as calcium ion and magnesium ion. Specific examples of anions that can be supported on titanium phosphate Examples include halogen ions such as chlorine and bromine, and carbonate ions.

The preferred titanium phosphate in the present invention is a compound having an atomic ratio of titanium to phosphorus of 0.5 to 1.5, and particularly an atomic ratio of titanium to phosphorus of 0.8 to 1.5.
Titanium phosphate of 1.0 is a particularly preferred compound because it has particularly excellent ultraviolet shielding properties and transparency. If the atomic ratio of titanium to phosphorus is smaller than 0.5 or larger than 1.5, the ultraviolet shielding property may be reduced.

Specific examples of preferred titanium phosphate in the present invention include the following compounds. That is, Ti (OH) P
O ₄ , TiPO ₄ , Ti ₄ P ₆ O ₂₃ , TiP ₂ O ₇ , (Ti
O) ₂ P ₂ O ₇ , Ti ₂ O _1.3 (PO ₄ ) _1.6 , Ti (HP
O ₄ ) ₂ , Ti (HPO ₄ ) ₂ .H ₂ O, Ti (HPO ₄ ) _{2.
0.5H 2 O, Ti (HPO 4} ) is ₂ · 2H ₂ O or the like.

The crystallinity of the titanium phosphate in the present invention may be either amorphous or crystalline.
There are transformations such as α, β, and γ, but there is no particular limitation.

The average particle size of the titanium phosphate in the present invention is as follows:
It is 0.1 μm or less. If the average particle size is larger than 0.1 μm, the transparency of the ultraviolet shielding agent is significantly impaired. A preferable average particle size is 0.02 to 0.08 μm in consideration of the dispersibility of the ultraviolet shielding agent in the dispersion medium.
It is.

The titanium phosphate in the present invention can be easily synthesized by a known so-called wet method. Preferred raw materials for titanium include titanium oxysulfate, titanium sulfate, titanium oxychloride, titanium tetrachloride, hydrous titanium oxide and oxidized titanium. There are titanium and the like, and preferable raw materials of the phosphoric acid include phosphoric acid such as metaphosphoric acid, pyrophosphoric acid, orthophosphoric acid, triphosphoric acid and tetraphosphoric acid, sodium phosphate, potassium phosphate, and ammonium phosphate.

The titanium phosphate in the present invention can be easily obtained by reacting the above-mentioned titanium raw material and the phosphoric acid raw material in water, followed by filtration, washing and drying in accordance with a well-known inorganic powder synthesis method. . The preferred charging ratio of the titanium raw material and the phosphoric acid raw material is a ratio in which the atomic ratio of titanium to phosphorus in the raw material mixture is 0.5 to 1.5,
The preferred reaction temperature is between room temperature and 120 ° C., and the preferred reaction time is between 10 minutes and 4 hours.

The average particle size of the titanium phosphate obtained as described above and the atomic ratio of titanium to phosphorus can be easily controlled by the raw material charging ratio, reaction temperature, reaction time, and the like.

Method of Use The ultraviolet shielding agent of the present invention can be applied to various materials, and specifically, coating agents such as resin, compounding on paper, coating on glass, dispersing in liquid, and paint. Can be used. Materials to which the ultraviolet shielding agent of the present invention can be applied include nylon, polyester, polyolefin, polyvinyl chloride, ABS,
Resins such as polycarbonate, polyurethane and silicone rubber; paper such as Japanese paper and synthetic paper using resin fibers as binders; glass such as window glass, optical equipment glass, contact lenses and fibrous glass; water, ethyl alcohol, acetone, There are liquids such as toluene, ethyl ether, ethylene glycol and various organic solvents. The preferred blending ratio of the ultraviolet shielding agent of the present invention may be appropriately adjusted depending on the type and use of the material to be blended, and is usually 0.01 to 10% by weight based on the total weight of the material blended with the ultraviolet shielding agent. .

Uses The ultraviolet screening agent of the present invention includes cosmetics, sunscreen creams, paints, resin modifiers, fiber modifiers, film coating agents,
It is particularly useful as a color paper coating, a wallpaper coating, a lens coating, a sunglass coating, an organic pigment coating, a reagent bottle coating, and a photographic paper surface coating.

[0017]

The present invention will be described below in more detail with reference to examples. First, two types of titanium phosphate were synthesized. The average particle size of the synthesized titanium phosphate was measured by scanning electron microscope observation, and the atomic ratio of titanium to phosphorus in the titanium phosphate was measured as follows. That is, titanium phosphate was dissolved with hydrofluoric acid, the molar concentrations of titanium and phosphorus were measured by ICP emission spectrometry, and the molar ratio of titanium was divided by the molar concentration of phosphorus to calculate the atomic ratio of titanium to phosphorus. .

[0018]

Example 1 Titanium oxysulfate (TiOSO ₄ .nH ₂ O n = 1 to
2) 82.26 g, 85% phosphoric acid (H ₃ PO ₄ ) 214.62
g and 400 g of ion-exchanged water are mixed and stirred, and ion-exchanged water is added to make the total amount 800 g. This is put in a 1-liter polyethylene bottle, and shaken for 30 minutes while keeping the temperature at 40 ° C. did. Thereafter, the reaction product was filtered and washed with ion-exchanged water until the electric conductivity of the filtrate became 100 μS / cm or less. After the washed filtrate was dried at 100 ° C., it was lightly pulverized with a small pulverizer (produced by Iuchi Corporation) to obtain titanium phosphate A. Titanium phosphate A
Had an average particle size of 0.06 μm and an atomic ratio of titanium to phosphorus of 1.0. Titanium phosphate A is used as ultraviolet ray shielding agent A.

[0019]

Example 2 Titanium phosphate B was obtained in the same manner as in Example 1 except that the reaction temperature was changed to 120 ° C. instead of 40 ° C., and the reaction time was changed to 120 minutes instead of 30 minutes. Titanium phosphate B had an average particle size of 0.06 μm and an atomic ratio of titanium to phosphorus of 0.9. Titanium phosphate B is used as ultraviolet shielding agent B.

[0020]

[Use example 1] 0.1% by weight based on the total weight after blending the ultraviolet ray shielding agent A obtained in Example 1 with soft vinyl chloride
The mixture was heated and kneaded at 150 ° C. by a roll forming machine, and a molded body A having a thickness of 0.5 mm was obtained by a hot press machine.

[0021]

Use Example 2 A molded product B was obtained in the same manner as in Use Example 1 except that the ultraviolet ray shielding agent B was used instead of the ultraviolet ray shielding agent A.

[0022]

[Comparative Use Example 1] Use example except that UV-shielding agent C consisting of α-titanium phosphate (atomic ratio of titanium to phosphorus: 0.5) having an average particle size of 0.2 μm was used in place of UV-shielding agent A Molded product C was obtained in the same manner as in 1.

[0023]

[Comparative Use Example 2] Molding was performed in the same manner as in Use Example 1 except that the ultraviolet shielding agent A was replaced with an ultraviolet shielding agent D made of titanium dioxide (P25 manufactured by Nippon Aerosil Co., Ltd.) having an average particle size of 0.05 μm. Obtained body D.

[0024]

Comparative Example 3 The procedure of Example 1 was repeated except that the ultraviolet ray shielding agent A was replaced with an ultraviolet ray shielding agent E made of zinc oxide (trade name: ZNOUVE manufactured by Mitsui Kinzoku Mining Co., Ltd.) having an average particle size of about 0.1 μm. A molded product E was obtained in the same manner.

Next, the molded articles A to E obtained as described above
Was evaluated for ultraviolet shielding properties and weather resistance by the following methods. -Evaluation of ultraviolet shielding properties Measurement of absorbance Spectrophotometer (trade name: UV-24 manufactured by Shimadzu Corporation)
0), the absorbance (O
D ₃₀₀ nm). In order to offset the influence of soft vinyl chloride, the same kind of soft vinyl chloride as that used for molding in Example 1 was used as a control.

Measurement of Transparency Using a turbidimeter (trade name: 80NDH type, manufactured by Nippon Denshoku Industries Co., Ltd.), the turbidity (HA
ZE) was measured.

Calculation of the ratio of the absorbance to the transparency The absorbance (OD300 nm) measured above was divided by the turbidity (HAZE) measured above (OD300 nm / H).
AZE. Hereinafter, abbreviated as standardized ultraviolet shielding property) was calculated. When the ultraviolet ray shielding material X is kneaded into the transparent resin R, the ultraviolet ray shielding property of the resin R tends to be directly proportional to the mixing ratio of the ultraviolet ray shielding substance together with the turbidity. Is directly proportional to turbidity. Therefore, when evaluating the ultraviolet shielding property in comparison with another ultraviolet shielding substance, it is necessary to keep the turbidity of the substance the same. Here, the influence of the turbidity is offset by dividing the absorbance by the turbidity as described above, and this ratio (OD
It can be said that as the value of (300 nm / HAZE) is larger, the turbidity is higher than the turbidity. In other words, the turbidity is lower (the transparency is higher) relative to the opacity. Table 1 below shows the molded articles A to
D shows the standardized ultraviolet shielding property.

[0028]

[Table 1] ────────────────── Sample OD300nm / HAZE ────────────────── Molded product A 0.083 Molded body B 0.081 Molded body C 0.055 Molded body D 0.057 Molded body E 0.053

From the results shown in Table 1 above, when an ultraviolet ray shielding agent is blended with a vinyl chloride resin at the same turbidity, the molded article A and the molded article B containing the ultraviolet ray shielding agent of the present invention are the same as those of the present invention. The molded product C containing an average particle size larger than that of the shielding agent and the molded product (D, E) containing a conventional ultraviolet shielding agent made of titanium dioxide or zinc oxide were about 50%.
It can be seen that the film has an ultraviolet shielding property that is larger by%.

The transmission spectrum of the molded article A was measured using the same spectrophotometer as that used for measuring the absorbance, and the results are shown in FIG. A vinyl chloride resin was used). The diffuse reflectance spectrum of titanium phosphate A was measured using a diffuse reflectometer, and the results are shown in FIG. From the spectrum of FIG. 1, it can be seen that there is little transmitted light in the ultraviolet region near the wavelength of 300 nm, which means that ultraviolet light absorption or reflection occurs in the ultraviolet region near the wavelength of 300 nm. . On the other hand, it can be seen from the spectrum of FIG. 2 that the reflected light sharply decreases in the ultraviolet region having a wavelength of 380 nm or less. Therefore, considering the result of FIG. 2, the wavelength 300 in the spectrum of FIG.
It can be seen that the peak near nm is due to absorption of ultraviolet light.

Evaluation of weather resistance Weather resistance tester (trade name UVCO manufactured by Atlas Co., Ltd.)
Using N), a forced deterioration test in which a cycle consisting of heating for 4 hours at a relative humidity of 90% and a temperature of 60 ° C. and irradiating ultraviolet rays for 4 hours is repeated 12 times is performed, and then the above-described method for evaluating ultraviolet shielding properties is performed. Similarly, the standardized ultraviolet shielding property was calculated. The results are shown in Table 2 below.

[0032]

[Table 2] ────────────────── Sample OD300nm / HAZE ────────────────── Molded product A 0.080 Molded body B 0.083 Molded body C 0.055 Molded body D 0.053 Molded body E 0.033

As is clear from the comparison between Tables 1 and 2, both of the molded products A and B have almost no change in the standardized ultraviolet shielding property before and after the forced deterioration test and are excellent in weather resistance. You can see that.

X Powder X-ray Diffraction The powder X-ray diffraction of the ultraviolet shielding agents A to D was performed under the conditions shown in Table 3 below. The result is shown in FIG.

[0035]

[Table 3]

The following can be seen from the X-ray diffraction diagram of FIG. That is, since the ultraviolet ray shielding agent A has almost no diffraction peak, it is amorphous titanium phosphate, and the ultraviolet ray shielding agent B is 2θ.
Is crystalline titanium phosphate having broad peaks at 8.4 °, 17.2 °, and 27.0 °, and ultraviolet ray shielding agent C is crystalline α-titanium phosphate, and ultraviolet ray shielding agent D
Is crystalline titanium dioxide.

[0037]

The ultraviolet shielding agent of the present invention has various characteristics such as fine particles having high transparency, high ultraviolet shielding property, excellent heat resistance, and high weather resistance. Therefore, the ultraviolet shielding agent of the present invention is hardly deteriorated by heat even after being added to the resin and molded by heating, and the molded resin is exposed to sunlight for a long time without impairing the original color tone and transparency of the resin. Even so, the ultraviolet shielding property can be maintained. The ultraviolet shielding agent of the present invention is, for example, useful as a modifier for an ultraviolet shielding coating used in places where transparency is required and used under severe conditions, for example, high-rise buildings or window glasses of automobiles, Also, since it is highly safe for living organisms and has good elongation to the skin, it exerts an excellent effect as a compounding agent for cosmetics.

[Brief description of the drawings]

FIG. 1 is a transmission spectrum diagram of a molded article A produced in use example 1.

FIG. 2 is a diagram showing a diffuse reflection spectrum of titanium phosphate A prepared in Example 1.

FIG. 3 shows an ultraviolet shielding agent A (Example 1) and an ultraviolet shielding agent B
(Example 2) It is an X-ray-diffraction figure about ultraviolet-ray shielding agent C (comparative example 1) and ultraviolet-ray shielding agent D (comparative example 2).

Claims (2)

[Claims] 1. An ultraviolet shielding agent comprising titanium phosphate having an average particle size of 0.1 μm or less. 2. The method according to claim 1, wherein the atomic ratio of titanium to phosphorus in the titanium phosphate is 0.5 to 1.5.
The ultraviolet shielding agent according to the above.