JPH08120256A - Ultraviolet-intercepting agent - Google Patents

Abstract

PURPOSE: To obtain an ultraviolet-intercepting agent which is excellent in ultraviolet-intercepting effect, is a fine powder excellent in dispersion stability, and is so chemically stable that it, hardly undergoes changes in quality, by using a layered silicate mineral which contains metal ions intercalated between layers. CONSTITUTION: Metal ions are selected from among the groups of iron, aluminum, titanium, zinc, copper alkaline earth metals, and chromium. A layered silicate mineral as the raw material is a clay mineral belonging to the smectite group, including montmorillonite, etc. The intercalation is done by using a salt of one of the above metals (e.g. iron chloride), i.e., subjecting the silicate mineral to water elutriation, removing the precipitate, adding the salt to the supernatant liq., and conducting the intercalation under stirring at room temp., a pH of 10 or lower, and a cation-exchange rate of 90% or higher. The resulting product is filtered to separate solids, and the solids are dried and ground to give the objective product. The salt is added in an amt. of 3-20wt.% of the silicate mineral.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a UV protection agent having a layered silicate mineral.

[0002]

2. Description of the Related Art Ultraviolet rays have an adverse effect on human skin such as suntan, sunburn, photosensitivity dermatitis, acceleration of skin aging, and skin cancer. These things have become widely recognized, and it has been attempted to impart an ultraviolet protection function to various things such as cosmetics and clothes. For example, in the case of cosmetics, an ultraviolet ray-preventing effect is given by adding an inorganic ultraviolet ray-scattering agent composed of fine particles of titanium oxide or an organic ultraviolet-absorbing agent composed of a phenolic substance having a conjugated double bond.

[0003]

However, the inorganic ultraviolet scattering agent has problems such as deterioration of usability due to microparticulation, reaggregation after microparticulation, and reduction of light resistance due to photocatalytic activity. Further, in the case of an organic ultraviolet absorber, there is a problem in that there is a limit in terms of prescription. From these things, it has an excellent effect of preventing ultraviolet rays, is chemically stable, and is not easily restricted by prescription by being mixed with various types and forms of materials.
The development of new UV protection agents has been desired.

[0004]

As a result of intensive studies to solve the above problems, the present inventors have found that a layered silicate mineral in which metal ions are intercalated between layers exhibits an excellent ultraviolet blocking action. The present invention has been completed based on this finding. That is, the present invention provides (1) an ultraviolet protective agent having a layered silicate mineral in which metal ions are intercalated between layers, (2) the metal ions are iron group, aluminum group, titanium group, zinc group, A metal selected from the group consisting of copper, alkaline earth metals and chromium (1)
The ultraviolet protection agent according to the item, and (2) the metal ion is iron,
The ultraviolet protection agent according to item (1) is aluminum, nickel, zirconium, zinc, copper, barium or titanium.

The layered silicate mineral used in the present invention is composed of a tetrahedral sheet in which silica-oxygen tetrahedra are two-dimensionally continuous in a net shape and an octahedral sheet in which octahedra such as aluminum-oxygen are continuous in a net shape. It consists of combinations and can take various shapes depending on the combination. The surface of the layer has a property of adsorbing cations because it has a negative charge, but the cations that enter the layers have a weaker bond than an ionic bond and can be freely exchanged with other cations. Therefore, various ion exchange reactions can be performed on the layer surface. The present inventors have defined this exchangeable ion as an iron group such as iron and nickel, an aluminum group such as aluminum, a titanium group such as titanium and zirconium, a zinc group such as zinc, a family member such as copper, and an alkaline earth metal such as barium. It has also been found that when exchanging with ions of a metal selected from the genus of chromium such as tungsten, the layered silicate mineral, which has almost no property of blocking ultraviolet rays, has an excellent ultraviolet blocking effect.

The method for producing the ultraviolet protective agent of the present invention will be described. The layered silicate mineral as a raw material is a clay mineral belonging to the genus Smectite, generally montmorillonite, beidellite, nontronite, saponite, hectorite, etc., which may be natural or synthetic, Montmorillonite is preferred. As commercial products, Kunipia (Kunimine Industry Co., Ltd.), Smecton (Kunimine Industry Co., Ltd.), Veegum (Vanderbilt Co., Ltd.), Laponite (Laporte Co., Ltd.), Fluorotetrasilicon mica (Topy Industry Co., Ltd.) and the like can be used. The intercalation can be performed using the metal salt of the above metal. Such metal salts include iron chloride, aluminum chloride, nickel chloride,
Zirconium chloride, zinc chloride, copper chloride, barium chloride,
Examples include titanium chloride. Water is added to the starting layered silicate mineral, for example, a metal chloride or the like is added and stirred, and intercalation is performed by a usual method. The raw lamellar silicate mineral is preferably purified from a raw ore and used. That is, after elutriating the raw ore and removing the precipitate, a metal salt is added to the supernatant and intercalation is carried out under stirring. Next, the liquid is filtered to separate the solid content, which is dried and, if necessary, pulverized to obtain the desired ultraviolet protective agent. The amount of the metal salt added is determined by the cation exchange capacity of the layered silicate mineral, and in many cases, 2 parts by weight or more, preferably 3 to 2 parts by weight based on 100 parts by weight of the layered silicate mineral.
It is 0 parts by weight, but is not limited thereto. The intercalation reaction is carried out so that the cation exchange rate of the layered silicate mineral is preferably 85% or more, particularly preferably 90% or more. The pH of the liquid used for the intercalation is preferably 10 or less, and the temperature is usually room temperature. The layered silicate mineral in which the metal ions are intercalated is used by being dried as a powder or dispersed in a predetermined amount of an aqueous medium.

[0007]

EXAMPLES Next, the present invention will be described in more detail based on examples. Example 1 Bentonite raw ore whose main component is montmorillonite produced in Yamagata Prefecture is crushed using a crushing roll, 3 kg of the obtained crushed raw ore is put into a 50-liter beaker, and water is added to bring the total weight to 30 kg. Was allowed to stand for 24 hours to swell. Then, after stirring this for 30 minutes using a stirrer,
After standing for 20 hours, the precipitate was removed by decantation. The resulting clear liquid was separated by a centrifuge to obtain a solid content of 2.
A supernatant containing 7% was obtained. This was designated as a purified layered silicate mineral (I). (The same thing as the commercially available Kunipia (Kunimine Industries Co., Ltd.) was obtained.) 3 kg of this purified layered silicate mineral (I) was placed in a 5 liter beaker, and iron chloride was added to 6.3 with stirring with a stirrer.
g was added. Then put it in a Buchner funnel and filter with suction,
After drying at 105 ± 5 ° C., it was pulverized, and layered silicate minerals (Sample No.
1) 81 g was obtained. The particle size of this product was 42 μm. This sample No. For each of 1 and the untreated purified layered silicate mineral, the transmittance of ultraviolet rays (wavelength 300 to 500 nm) of the suspension having a concentration of 0.125% was measured with a self-recording spectrophotometer U-3200 (manufactured by Hitachi Ltd.). did. Table 1 shows the results.

[0008]

[Table 1]

It can be seen from Table 1 that intercalation of metal ions between the layers causes a remarkable ultraviolet scattering effect on the layered silicate mineral, which has a low ultraviolet scattering effect and could not be used as an ultraviolet protective agent. .

Example 2 An aluminum ion-intercalated layered silicate mineral (Sample No. 2) was prepared in the same manner as in Example 1 except that iron chloride was changed to aluminum chloride and 5.2% by weight was added. ) Was produced. Example 3 A layered silicate mineral intercalated with nickel ions (Sample No. 3) was prepared in the same manner as in Example 1 except that iron chloride was changed to nickel chloride and 7.6% by weight was added.
3) was produced. Example 4 A layered silicate mineral (Sample No. 4) in which zirconium ions were intercalated was prepared in the same manner as in Example 1 except that iron chloride was changed to zirconium chloride and 6.8 wt% was added. did. Example 5 A layered silicate mineral in which zinc ions were intercalated (Sample No. 5) was produced in the same manner as in Example 1 except that iron chloride was changed to zinc chloride and 7.9% by weight was added. did. Example 6 A layered silicate mineral (sample No. 6) in which copper ions were intercalated was produced in the same manner as in Example 1 except that iron chloride was changed to copper chloride and 7.8% by weight was added. did. Example 7 A layered silicate mineral in which barium ions were intercalated (Sample No. 4) was prepared in the same manner as in Example 1 except that iron chloride was changed to barium chloride and 12.1% by weight was added.
7) was produced.

These sample Nos. The ultraviolet transmittances of the suspensions 2 to 7 (concentration 0.125%) were measured by the same method as in Example 1. The results are shown in Table 2. In addition, Example 1
The cation exchange capacity of the purified layered silicate mineral (I) used in Example 7 was 117.5 meq / 100 g. In addition, the sample No. When producing 1 to 7, the amount of sodium chloride contained in the filtrate obtained by solid-liquid separation was analyzed to determine the exchange rate of metal ions, and the values were as shown in Table 3.

[0012]

[Table 2]

[0013]

[Table 3]

As is clear from the results shown in Table 2, all of the layered silicate minerals in which each metal ion is intercalated have an excellent ultraviolet light scattering action and can be effectively used as an ultraviolet light protective agent.

Sample N obtained in Examples 1 to 7 above
o. The particle sizes of 1 to 7 were measured and were as follows.

[0016]

[Table 4]

Reference Example The following compositions were kneaded by a roll mill by a conventional method,
Sample No. manufactured in Example 1 A uniform foundation with 1 was prepared. (Wt%) Sample No. 1 5.2 Liquid paraffin 15.0 Propylene glycol monostearate 6.0 Stearic acid 2.5 Sodium lauryl sulfate 1.1 Triethanolamine 1.3 Pigment 11.0 Purified water 53.1 Bentonite 4.7 Paraoxybenzoic acid Methyl 0.1 Fragrance Appropriate amount The foundation obtained was concentrated to 0.07% and 0.1
A 7% suspension was prepared and the ultraviolet transmittance at a wavelength of 300 nm was measured. The results are shown in Table 5.

[0018]

[Table 5]

From the results shown in Table 5, it can be seen that the foundation containing the ultraviolet protective agent of the present invention effectively exhibits an ultraviolet protective action.

[0020]

As is clear from the above results, the UV protective agent of the present invention is excellent in UV blocking effect and is fine particles,
It has excellent dispersion stability, is chemically stable and does not easily deteriorate. This UV protection agent can be used in various applications such as cosmetics, resins, paints and fibers.

Claims (3)

[Claims] 1. An ultraviolet protective agent having a layered silicate mineral in which metal ions are intercalated between layers. 2. The ultraviolet protection agent according to claim 1, wherein the metal ion is a metal selected from the group consisting of iron group, aluminum group, titanium group, zinc group, copper group, alkaline earth metal and chromium group. 3. The ultraviolet protection agent according to claim 1, wherein the metal ion is iron, aluminum, nickel, zirconium, zinc, copper, barium or titanium.