JP2002114964A - UV protection agent and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a UV protective agent which has excellent ultraviolet blocking function, is fine particles, has excellent dispersion stability, is chemically stable and is hardly deteriorated, and is inexpensive and easily obtainable. A manufacturing method is provided. SOLUTION: Inorganic mineral particles (for example, montmorillonite, mica calcium carbonate) are used as a core material, and the surface thereof is coated with a substance having an ultraviolet protection effect (for example, titanium oxide, zinc oxide) by surface fusion or bonding. UV protection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an ultraviolet ray protective agent and a method for producing the same. More specifically, a resin composition,
The present invention relates to an ultraviolet ray protective agent which can be used for films, packaging materials, fibers, cosmetics, paints and the like and can impart an excellent ultraviolet ray protective function, and a method for producing the same.

[0002]

2. Description of the Related Art Ultraviolet rays have an adverse effect on human skin, such as causing suntan, sunburn, photosensitive dermatitis, promoting skin aging, and causing skin cancer. In recent years, this has been widely recognized, and attempts have been made to impart an ultraviolet ray preventing function to various things such as cosmetics and clothing. For example, in the case of cosmetics, an ultraviolet ray preventing effect is imparted by blending an inorganic ultraviolet ray scattering agent composed of fine particles of titanium oxide or an organic ultraviolet ray absorbent composed of a phenolic substance having a conjugated double bond. However, inorganic ultraviolet scattering agents have problems such as deterioration of usability due to fine particles, reaggregation of dispersed fine particles, and decrease in light resistance due to photocatalytic activity. In the case of an organic ultraviolet absorber, there is a problem that the amount that can be prescribed is limited. Further, organic UV protective agents are often used by dissolving them in an oily solvent, and their uses are limited.

[0003]

Therefore, the present invention is excellent in the function of preventing ultraviolet rays, is chemically stable and does not deteriorate,
It is an object of the present invention to provide an ultraviolet protective agent which has a good dispersion stability and is hardly restricted by formulation by being blended in a desired amount with various types and forms of materials, and a production method thereof which is inexpensive and easily obtained.

[0004]

Means for Solving the Problems The present inventor has conducted intensive studies in view of the above-mentioned problems, and as a result, has found that inorganic mineral particles are used as a core material and a substance having an ultraviolet protection effect is fused or bonded to the surface of the core material to form a film. The inventors have found that the complex formed is an ultraviolet protective agent having a high ultraviolet protective action, and based on this finding, have accomplished the present invention.

That is, the present invention provides (1) an ultraviolet ray protective agent characterized in that the surface of inorganic mineral particles is coated with an ultraviolet ray protective substance fused or bonded thereto, and (2) the ultraviolet ray protective substance has an ultraviolet ray protective action. And (3) the inorganic mineral particles are any one of mica clay minerals, layered silicate minerals, silica minerals, carbonate minerals and sulfate minerals. Consisting of more than species
(1) The ultraviolet protective agent according to (1) or (2), (4) the ultraviolet protective substance is selected from iron group, aluminum group, titanium group, zinc group, copper group, cerium group, alkaline earth metal or chromium group. (5) The ultraviolet ray protective agent according to the item (1), which is a metal or metal oxide, and (5) a surface fusion or bonding of the ultraviolet ray protective substance to the surface of the inorganic mineral particles by mechanically complexing treatment by rotational movement. And a method for producing an ultraviolet protective agent.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The inorganic minerals serving as the core material of the ultraviolet protective agent of the present invention include mica clay minerals such as muscovite, sericite and illite, and layered materials such as montmorillonite, saponite, hectorite, stevensite and acid clay. Silica minerals such as silicate, quartz, and opal, carbonate minerals such as calcium carbonate and dolomite, and sulfate minerals such as gypsum and alunite can be used. These may be natural products or synthetic products, but it is preferable to use natural products from the viewpoint of economy. Any of these may be used alone, or two or more of them may be used in combination. The average particle size of the inorganic mineral can be appropriately set and is not particularly limited, but is preferably 100 μm or less, and preferably 0.05 to 3 μm.
0 μm, more preferably 2 to 15 μm. If the particle size of the inorganic mineral is too large, the dispersibility is poor, and when blended in a resin, a paint, or the like, discoloration may occur due to sedimentation or obstruction of light transmission. On the other hand, when the amount is too small, the effect cannot be obtained unless the added amount is increased, and the ultraviolet protection effect may be reduced. The shape of the inorganic mineral particles may be any shape such as a layer shape, a plate shape, a fiber shape, etc., in addition to a spherical shape. The surface properties of the inorganic mineral particles used in the present invention are not particularly limited, but those having a microporous surface or a smooth surface are preferred.

[0007] There is no particular limitation on the UV protective substance that coats the surface of the inorganic mineral. Examples of the ultraviolet protection substance in the present invention include iron group such as iron and nickel, aluminum group such as aluminum, titanium group such as titanium and zirconium, zinc group such as zinc, copper group such as copper, cerium group such as cerium, and barium. And a metal or metal oxide selected from the chromium group such as tungsten or an alkaline earth metal. Examples of such a metal oxide include iron oxide, aluminum oxide, zirconium oxide, zinc oxide, copper oxide, titanium oxide, and cerium oxide, and most preferably, titanium oxide, zinc oxide, and cerium oxide are used.

[0008] This ultraviolet protective substance is a dry type, which is formed into a thin film under the application of shearing stress, and is fused or bonded to the surface of the inorganic mineral particles to form a film and coat the surface of the inorganic mineral particles. The average particle size of the ultraviolet protection substance is set to 1/1 to 1/1000 of the inorganic mineral particles, preferably 1/6 to 1/1000.
800. The finer the UV protection particles, the better. If the particle size of the UV-protective particles is too large, the specific surface area will be small, and it will not be possible to cover the inorganic mineral particles densely, resulting in a decrease in UV-protection performance.
In the present invention, the coating of the ultraviolet protective particles covering the surface of the inorganic mineral particles with the ultraviolet protective particles may partially cover the surface of the inorganic mineral particles, but most preferably covers the entire surface. Is what it is. In the case of partial coating, it is more preferable to cover at least 60% or more of the surface. The amount of the UV protective particles used varies depending on the type of the inorganic mineral and the UV protective particles, but is usually 0.5 to 50% by weight, preferably 1 to 40% by weight of the inorganic mineral. The thickness of the film as a coating layer of the ultraviolet protection agent is 0.0
The thickness is set to 1 to 5.0 μm, preferably 0.05 to 1.0 μm.

In the ultraviolet protective agent of the present invention, since the coating layer of the ultraviolet protective particles is fused or bonded to the surface of the inorganic mineral serving as the core, it can be peeled off even when dispersed in an aqueous system. There is no. Therefore, for example, when a swellable layered silicate is used for the core material, the UV-protective particle layer does not peel off even if the core material swells in an aqueous system. It is possible to obtain an excellent ultraviolet protection agent having an ultraviolet protection property without impairing the properties of the core material, for example, it can be used as a system ultraviolet protection agent. Further, by adding a coloring agent such as a pigment or a dye to the inorganic mineral, an ultraviolet protective agent having a desired color and physical properties can be obtained.

[0010] The surface fusion or bonding between the inorganic mineral and the ultraviolet protective particles is formed by a mechanical complexing treatment. The mechanical compounding treatment of the method of the present invention is a treatment in which a physical force is exerted on the powder by the rotational movement of the device. For example, the inorganic mineral and the UV-protective particles exert centrifugal force on the inner wall of the rotating casing. In this casing, there is a stationary arm with an arc-shaped head, and due to the difference in curvature between this head and the inner wall of the casing, the powder layer caught between the two is rapidly compressed and strong. This is a method for producing an ultraviolet ray protective agent by receiving an appropriate protection. A device generally used as a fine pulverizer can be used. For example, a high-speed rotary impact pulverizer (pin mill, disk mill), a grinding mill, a medium stirring type pulverizer,
Cosmos (trade name, manufactured by Kawasaki Heavy Industries Co., Ltd.), mechanofusion system (trade name, manufactured by Hosokawa Micron Corporation), sheeter composer (trade name, manufactured by Tokuju Kogyo Co., Ltd.), etc., and it is particularly preferable to use the mechanofusion system .

The process of producing the ultraviolet protective agent by mechanical complexation is considered as follows. First, the ultraviolet protective particles adhere and grow on the surface of the inorganic mineral particles serving as the core material, and the specific surface area of the inorganic mineral particles decreases while increasing the adhesion rate with the treatment time. Then, after the increase in the adhesion rate has stopped, the UV protective particles on the surface of the core material become denser,
The specific surface area further decreases with the processing time. In this way, the inorganic mineral particles and the UV protection particles are fixed to the inner wall of the rotating casing and receive a very strong shearing action under a strong compressive force in the gap between the inner piece with the head with a curvature, Thereafter, the process of stripping and mixing with a scraper is repeated. Since the compression and shearing effects act simultaneously, the individual particles tend to rotate in the powder layer, and the fusion of the particles is promoted by the relative friction between the particles, so that the fine particles of the UV protection particles are densely coated. A complex is formed in which the layers are tightly bound to the surface of the inorganic mineral particles.
Therefore, it is possible to change the microstructure of the coating layer of the ultraviolet protection agent by changing the stress condition and the processing time of the rotational movement of the apparatus, and it is possible to adjust the ultraviolet protection performance. The temperature is raised by this mechanical treatment, but the temperature is 20 to 2
The temperature is set to 50 ° C, preferably 80 to 150 ° C. It is necessary to adjust the number of revolutions, the geometrical factor of the device, the flow of air in the device, and the like so that the stress condition is at least equal to or less than the fracture limit of the inorganic mineral, preferably 100 to 3000 rpm, more preferably 1000 to 2500 rpm. Perform processing.
The processing time is usually 1 minute or more, preferably 10 to 60 minutes. Even if the complex obtained by the mechanical complexing process is shaken in a solvent or atomized, observation with an electron microscope shows that the coating layer of the UV protective particles is stable on the surface of the inorganic mineral particles. Is attached.
Since the method of the present invention is a dry method using no solvent, no solvent remains in the produced ultraviolet protective agent. In addition, a process for removing the solvent is not required, and the device can be easily manufactured.

[0012]

Next, the present invention will be described in more detail with reference to examples. Example 1 Montmorillonite (trade name: Kunipia, manufactured by Kunimine Industries Co., Ltd., average particle size: 15 μm) 95% by weight and titanium oxide (trade name: Taipaque, manufactured by Ishihara Sangyo Co., average particle size: 0.02 μm)
m) 5% by weight was treated with a mechanofusion system (manufactured by Hosokawa Micron Corp., AM-15F type) at 2000 rpm for 60 minutes to obtain an ultraviolet ray protective agent (average particle size: 14 μm, thickness of titanium oxide film: 0.06 μm). Was. In addition, the result of having observed the structure of the particle | grains at the processing time of 20 minutes, 40 minutes, and 60 minutes with an electron microscope is shown in FIG. From FIG. 1, it can be understood that titanium oxide forms a dense coating layer on the surface of montmorillonite. Example 2 Plate-shaped mica (Yamaguchi Mica Industrial Co., Ltd., average particle size 8 μm)
m) 95% by weight and 5% by weight of the same titanium oxide used in Example 1 were treated in the same manner as in Example 1 to give an ultraviolet ray protective agent (average particle size: 8 μm, thickness of titanium oxide film: 0.07 μm)
m). Example 3 Calcium carbonate (Nitto Powder Chemical Co., Ltd., average particle size 2 μm)
95% by weight and 5% by weight of zinc oxide (manufactured by Kanto Kagaku Co., Ltd., crushed to an average particle size of 0.8 μm by a jet mill) were treated in the same manner as in Example 1, and an ultraviolet protective agent (average particle size of 2 μm, zinc oxide) (Thickness of the film of 0.05 μm) was obtained. Example 1
The ultraviolet protective agent obtained in 3 was used as a suspension having a concentration of 0.125%, and the transmittance of ultraviolet rays (wavelength: 300 to 500 nm) was measured with a self-recording spectrophotometer U-3200 (manufactured by Hitachi, Ltd.). For comparison, untreated montmorillonite powder (trade name: Kunipia, manufactured by Kunimine Industries, average particle size 15 μm)
, The ultraviolet transmittance was measured in the same manner. Table 1 shows the results.

[0013]

[Table 1]

From Table 1, it was found that an ultraviolet ray protective agent having a function of protecting ultraviolet rays can be obtained by surface fusion or bonding of ultraviolet ray protective particles to inorganic mineral particles.

In addition, even if the composite particles obtained by the mechanical composite treatment of the example are shaken in a solvent or subjected to an atomizer treatment, electron micrograph observation shows that the ultraviolet protective agent is stable on the surface of the inorganic mineral particles. Was attached. Comparative Example 95% by weight of montmorillonite as used in Example 1
And 5% by weight of titanium oxide were stirred at 1200 rpm for 10 minutes with an Erich mixer (Nippon Erich Co., R02 type) to obtain a composite. The ultraviolet protective agent obtained in Example 1 and the complex obtained in this comparative example were each dispersed in water at a concentration of 4% by weight, and the viscosity and dispersibility were examined. Dispersibility was evaluated by visually observing the degree of sedimentation.

[0016]

[Table 2]

The composite obtained in the comparative example is a surface-coated composite that has not been subjected to surface fusion or bonding.
It is considered that the titanium oxide on the surface was peeled off in water, the titanium ions exchanged with the ions between the layers of montmorillonite, and the montmorillonite aggregated and settled. However, the ultraviolet protective agent of the present invention obtained in Example 1 has excellent dispersibility without impairing the viscosity, which is the inherent property of montmorillonite, because the titanium oxide coating the surface does not peel off. Understand.

Reference Example Next, an example in which the ultraviolet protective agent obtained in the present invention is used in a foundation will be described. 90% by weight of montmorillonite and 10% by weight of titanium oxide used in Example 1 were treated in the same manner as in Example 1 to obtain an ultraviolet protection agent. This UV protection agent was added to and mixed with a commercially available foundation (commercially available product A) at 10% by weight and 30% by weight, respectively. These three types of ultraviolet transmittance, including those not mixed, were measured in the same manner as described in Example 3. The result is shown in FIG. FIG. 3 shows the result of measuring the ultraviolet transmittance of a commercially available UV cut foundation for reference. Commercially available TiO _{2 of} A, B, C
The contents are 1.8%, 18.4% and 29.1%, respectively.
It is. The mixture containing the ultraviolet protective agent of the present invention has an excellent UV shielding effect despite the low content of titanium oxide.

[0019]

As is clear from the above results, the ultraviolet protective agent of the present invention is excellent in the effect of blocking ultraviolet rays,
It has excellent dispersion stability and is chemically stable and hardly deteriorates. This UV protection agent can be used for various uses such as cosmetics, resins, paints, and fibers. In addition, since the production method is based on dry mechanical treatment, the steps and treatment operations are simple, and an inexpensive ultraviolet protective agent can be obtained.

[Brief description of the drawings]

FIGS. 1A, 1B, and 1C show the processing times of a mechanical compounding process in Example 1, 20 minutes, 40 minutes, and 6 minutes.
It is an electron micrograph which shows the structure of the particle | grains at 0 minute, respectively.

FIG. 2: 10 UV protection agents in a commercially available foundation
It is a figure which shows the transmittance | permeability of what mixed 30% and 30%.

FIG. 3 is a diagram showing the transmittance of a commercially available foundation.

Claims (5)

[Claims] 1. An ultraviolet ray protective agent, wherein an ultraviolet ray protective substance is surface-fused or bonded to the surface of an inorganic mineral particle and coated. 2. The ultraviolet protective agent according to claim 1, wherein the ultraviolet protective substance is a metal or a metal oxide having an ultraviolet protective action. 3. The ultraviolet protective agent according to claim 1, wherein the inorganic mineral particles comprise at least one of a mica clay mineral, a layered silicate mineral, a silica mineral, a carbonate mineral, and a sulfate mineral. 4. The method according to claim 1, wherein the ultraviolet ray protective substance is a metal or metal oxide selected from the group consisting of iron group, aluminum group, titanium group, zinc group, copper group, cerium group, alkaline earth metal and chromium group. UV protection agent. 5. A method for producing an ultraviolet ray protective agent, wherein an ultraviolet ray protective substance is surface-fused or bonded to the surface of inorganic mineral particles by mechanically complexing treatment by rotating motion.