JP2576824B2 - Ultraviolet ray blocking agent, resin composition containing the same and cosmetics - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inorganic ultraviolet blocking agent, and a resin composition and a cosmetic containing the same which have an excellent ultraviolet blocking effect and durability.

[0002]

2. Description of the Related Art It is well known that ultraviolet rays have a strong effect on living organisms, cause various changes to the skin, and deteriorate resin compositions. However, in order to avoid this effect, organic ultraviolet absorbers and inorganic ultraviolet rays are used. Various UV protection agents, called absorbers, have been developed and used.

[0003] When an organic material such as plastic absorbs ultraviolet rays, its constituent polymer or the like is excited to cause an organic photoreaction, thereby causing deterioration due to coloring or initiation of autoxidation. As a result, discoloration, generation of cracks, tensile strength, reduction in elongation, and the like are greatly affected by performance aspects. Therefore, as one of methods for preventing deterioration of plastics due to ultraviolet rays, an ultraviolet ray protective agent is added. Organic UV absorbers such as salicylic acid, benzophenone, benzotriazole and cyanoacrylate are often used for plastics. However, organic UV absorbers have low heat resistance and durability, so they will volatilize and decompose during processing. Due to safety issues, and its use was limited.

[0004] Recently, inorganic ultraviolet absorbers such as fine particle titanium oxide and fine particle zinc oxide have been developed. However, when these are used for plastics, problems such as poor dispersion and catalytic action occur. Further, conventionally, organic UV absorbers and inorganic UV absorbers have been used in cosmetics for the purpose of preventing the effects of ultraviolet rays on the skin. However, as in the case of plastics, organic UV absorbers have problems in stability and safety, and inorganic UV absorbers have problems such as dispersibility, opacity, and irritation to the skin.

[0005]

SUMMARY OF THE INVENTION In view of such circumstances, the present invention provides a colorless, transparent, highly dispersible, non-toxic, non-catalytic, and non-catalytic agent when formulated into plastics, fibers, paints, cosmetics, and the like. To provide a UV-blocking effect and a light-resistant resin composition and a highly safe cosmetic by blending this with an inorganic UV absorber excellent in heat resistance, chemical resistance and durability It is.

[0006]

The above objects are achieved by the present invention. That is, the present invention provides a refractive index of 1.45.
Natural silica having an average particle diameter of 0.1 to 50 μm,
Synthetic silica, a coating layer of insoluble cerium compound and amorphous silica provided on the particle surface of the particulate pigment composed of glass, etc.,
The gist of the present invention is an ultraviolet blocking agent characterized by being baked at 200 ° C. to 1000 ° C. for 30 minutes or more.

Hereinafter, the present invention will be described in more detail. The present inventors have conducted various studies on inorganic materials which have no toxicity or catalytic action when blended with an ultraviolet ray blocking agent in plastics, fibers, paints, cosmetics, etc., and which exhibit high transparency especially in plastics and high transparency. As a result, it was found that granular pigments such as natural silica, synthetic silica, and glass having a refractive index of 1.45 to 1.6 and an average particle diameter of 0.1 to 50 μm are suitable.

Using such a granular pigment as a starting material, an aqueous dispersion is prepared using a disperser or an emulsifier, and the aqueous dispersion is heated to 60 ° C. or higher, preferably 80 ° C., and added to cerium chloride and nitric acid. An aqueous solution of a cerium salt such as cerium or cerium sulfate is added dropwise. In this case, the addition amount is appropriately equivalent to 1 to 30% by weight as CeO _{2 with} respect to the granular pigment.

Subsequently, a phosphoric acid, a phosphate solution, a polyphosphoric acid solution, a carbonate solution such as sodium carbonate, aqueous ammonia,
When at least one kind of alkali hydroxide solution such as sodium hydroxide is added and the pH of the solution is adjusted to about 7 to 9, the insoluble cerium compound is deposited on the surface of the particulate pigment to form a coating layer.

In the present invention, this coating layer is filtered, washed with water,
It is important to bake after drying and pulverization. The firing temperature in this case is 200 ° C. to 1000 ° C., particularly 500 ° C.
As described above, when calcined for 30 minutes to 2 hours or more, a granular cerium-coated pigment is obtained. In the case of unfired or fired at 150 ° C. for 2 hours, no ultraviolet ray blocking action appears. In the sintering, the longer the temperature and the longer the temperature, the better the ultraviolet blocking effect, and finally a certain ultraviolet blocking effect is exhibited.
In addition, baking may be performed after the next silica coating, and the ultraviolet ray blocking action does not change.

The obtained granular cerium-coated pigment is dispersed in water using a disperser or an emulsifier. The pigment concentration of the dispersion is set to 40% by weight or less, and the aqueous dispersion is kept at 60 ° C. or higher, preferably 80% or higher. The silicate solution is added while heating and stirring at 0 ° C. The addition of the silicate causes amorphous silica to deposit on the particle surfaces of the particulate cerium-coated pigment. Deposition amount is suitably range from 2 to 40 wt% with respect to particulate pigment coated with the insoluble cerium compound as SiO _2.

At the same time, a mineral acid such as sulfuric acid or nitric acid is added,
After the addition of the silicate, the whole amount is added to adjust the pH of the solution to 9-1.
When the mixture is further stirred for 30 minutes or more and neutralized with a mineral acid, amorphous silica is deposited on the surface of the pigment particles, and the coating is completed. Cerium-silica-coated pigment of the present invention is obtained.

FIG. 1 shows the results of measuring the light transmittance of various ultraviolet ray blocking agents. The samples were those without a blocking agent, the conventional organic ultraviolet ray absorbing agent, and the synthetic silica ultraviolet ray shielding of the present invention. Agent (CeO ₂ coverage 30% by weight, Si
O ₂ coating amount 18 wt%), natural silica UV screening agent of the present invention (CeO ₂ coating amount 30 wt%, SiO ₂ coating amount 18 wt%), the zinc oxide particles, is ultrafine titanium dioxide.

From this figure, it can be seen that the sample and the sample have a slightly lower UV blocking effect in the 290 nm to 400 nm region, but are more excellent. Also, 400-800
The light transmittance in the nm range is slightly less, but better, indicating that it has sufficient transparency.

In this case, the light transmittance is such that the addition ratio is 3.0% with respect to the sample and the resin solid content, and the sample is such that the addition ratio is 1.0% with respect to the resin solid content. 0.4 ml of castor oil was added to the mixture to give a fiber muller (5).
After dispersing at 0 rpm × 2), 6 ml of clear lacquer was added and kneaded, and then this liquid was applied to a transparent quartz plate to a thickness of 35 μm, and a spectrophotometer (UV-2200 manufactured by Shimadzu Corporation) was used.
(Type).

Next, the resin composition and the cosmetic according to the present invention will be described. Generally, photodeterioration of a resin composition is caused by absorbing light having a wavelength of 290 nm or more (especially in the ultraviolet region), which is a wavelength region of sunlight, and further exciting a chemical reaction before excited singlet and triplet are deactivated. Be started. Even a polymer that does not have absorption in this region in the basic skeleton of the polymer causes photodeterioration due to the presence of a trace amount of UV-absorbing groups or impurities as starting points. In polyethylene, polypropylene, and the like, there is absorption tailing in this region, and it has been confirmed that there is absorption that causes photodegradation. Therefore, some measures against ultraviolet rays are required.

FIG. 2 shows the natural silica pigment ultraviolet blocking agent of the present invention (CeO ₂ coating amount 30% by weight, SiO ₂ coating amount 18
2 shows the result of measuring the light reflectance of the sample (% by weight).
This indicates that the ultraviolet blocking agent of the present invention absorbs light in the ultraviolet region well.

Therefore, the photodeterioration can be prevented or greatly reduced by adding the ultraviolet ray blocking agent of the present invention to the resin composition. It is more effective when used in combination with a conventionally used ultraviolet absorber. The term “resin composition” as used herein refers to all compositions including synthetic resins such as polyethylene and polyester and natural resins, as well as paints and the like containing these resins.

The ultraviolet ray blocking agent of the present invention is excellent in ultraviolet ray shielding property and has little irritation to the skin and no toxicity because its surface is coated with amorphous silica. Also, the dispersibility is excellent. Therefore, by blending it with various cosmetics, it is possible to obtain a cosmetic having a good dispersibility, an aesthetic appearance and a comfortable feeling of use, and a physicochemically stable and highly safe ultraviolet blocking effect. In addition, depending on the purpose of use, there is no problem when used in combination with a conventionally used ultraviolet absorber or the like.

[0020]

【Example】

(Example 1) 500 g of natural silica was dispersed in 10 liters of pure water, and then dispersed for 1 hour using a despamill (manufactured by Hosokawa Micron). While heating and stirring this dispersion at 80 ° C.,
Cerium nitrate aqueous solution (CeO ₂ content 19% by weight, insoluble cerium compound deposition amount 30% by weight as CeO ₂ ) 7
90 g are added dropwise. Subsequently, a sodium hydroxide solution was added to neutralize the pH of the solution to 7 to 9, and cerium hydroxide was deposited on the surface of natural silica to form a coating layer. This was filtered, washed with water, dried and pulverized to obtain a granular cerium-coated natural silica pigment.

After the granular cerium-coated natural silica pigment is dispersed in 10 liters of pure water, the dispersion is dispersed for 1 hour by a despamill. While heating and stirring this dispersion at 80 ° C. or higher, 3
No. sodium silicate (SiO ₂ content 28, 5% by weight,
Amorphous silica deposition amount 18% by weight as SiO ₂ ) 41
Add 1 g. The pH of the solution was maintained at 9 to 11 by adding sulfuric acid, and stirring was further continued for 1 hour. This was filtered, washed with water, dried and pulverized to obtain a granular cerium-silica-coated natural silica pigment. Next, this is 50
Baking at 0 ° C. for 2 hours, UV-blocking agent (CeO ₂ content 3
0% by weight and 18% by weight of SiO ₂ ).

(Example 2) The low-density polyethylene was blended with 0, 1, 2, 3, 4% by weight of an ultraviolet ray blocking agent of the granular cerium-coated natural silica pigment obtained in Example 1, and the mixture was heated with a roll. Into a film having a thickness of 50 μm. The light transmittance of these films was measured with a spectrophotometer (UV-2 manufactured by Shimadzu Corporation).
200 type), the result of FIG. 3 was obtained. From this figure, it was found that the higher the blending ratio, the higher the light blocking effect in the ultraviolet region, but that the ultraviolet blocking agent of the present invention maintained good transparency in the visible region. Next, the weather resistance test of the film containing 0% by weight and the film containing 3% by weight was carried out for 20 days.
A 0 hour sunshine weather meter test showed that the 0% by weight blended film was colored, but the 3% by weight blended film did not show any coloration, and had the same UV blocking properties as before the test. And good transparency.

Example 3 A liquid foundation was produced using the granular cerium-coated natural silica pigment obtained in Example 1 and the ultraviolet ray blocking agent according to the following composition and adjustment method. Composition: (1) 2.5% by weight of stearic acid (2) Propylene glycol monostearate 2.0 (3) Cetanol 0.3 (4) Liquid lanolin 2.0 (5) Liquid paraffin 2.5 (6) Isopropyl myristate 7.0 (7) Propyl paraoxybenzoate 0.1 (8) Purified water 57.9 (9) Sodium carboxymethylcellulose 0.2 (10) Bentonite 0.5 (11) 1 9., 3-butyleneglycol 5.0 (12) triethanolamine 1.2 (13) methyl paraoxybenzoate 0.2 (14) titanium oxide 5.0 (15) granular natural cerium-silica-coated natural silica pigments 10. 0 (16) Bengala 2.0 (17) Yellow iron oxide 1.5 (18) Black iron oxide 0.1 100.0% by weight in total

Preparation method: (14) to (18) are mixed well. Add (10) to (8) at 70 ° C and swell well,
(9) Add and dissolve the dispersions of (11) to (13). (1) to (7) are dissolved at 70 to 80 ° C (oil phase). When the mixture has been added, the mixture is passed through a colloid mill (aqueous phase). The aqueous phase is adjusted to 75 ° C., the oil phase is adjusted to 80 ° C., the oil phase is added to the aqueous phase to emulsify, and the mixture is stirred and cooled to 30 ° C. The liquid foundation obtained as described above had a transparent feeling and good elongation, and was excellent in an ultraviolet ray blocking effect and light resistance.

[0025]

The ultraviolet blocking agent of the present invention is particularly useful for UV-B
It has an excellent effect of blocking ultraviolet rays in the vicinity, has no toxicity or catalytic action, and is excellent in heat resistance, chemical resistance, dispersibility, and transparency. In addition, resin compositions such as plastics, fibers, and paints and cosmetics containing the ultraviolet blocking agent of the present invention have excellent ultraviolet blocking and light resistance.

[0026]

[Brief description of the drawings]

FIG. 1 is a curve diagram showing the relationship between the light transmittance and the wavelength of the ultraviolet blocking agent of the present invention and various conventional ultraviolet blocking agents.

FIG. 2 is a curve diagram showing the relationship between the light reflectance and wavelength of the ultraviolet blocking agent of the present invention.

FIG. 3 is a curve diagram showing the relationship between the light transmittance and the wavelength of various films in which the ultraviolet blocking agent obtained in Example 1 is blended with low-density polyethylene at 0, 1, 2, 3, and 4% by weight.

[Description of References] No Additive Sample Organic Ultraviolet Blocker Sample Synthetic Silica Blocker Sample of the Present Invention Natural Silica Ultraviolet Blocker Sample of the Present Invention Fine Particle Zinc Oxide Sample Fine Particle Titanium Oxide Sample a Film Sample without Additives Film sample with 1% UV-blocking agent c Film sample with 2% UV-blocking agent d Film sample with 3% UV-blocking agent e Film sample with 4% UV-blocking agent

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical indication location C09C 3/06 PBT C09C 3/06 PBT (56) References JP-A-1-190626 (JP, A JP-A-60-228406 (JP, A) JP-A-60-226805 (JP, A) JP-A-2-214478 (JP, A)

Claims (3)

(57) [Claims] (1) a refractive index of 1.45 to 1.6, and an average particle diameter of 0.
A coating layer of an insoluble cerium compound and amorphous silica provided on the particle surface of a granular pigment composed of 1 to 50 μm of natural silica, synthetic silica, glass, etc., is fired at 200 ° C. to 1000 ° C. for 30 minutes or more. Characterized ultraviolet blocking agent. 2. A resin composition comprising the ultraviolet blocking agent according to claim 1. 3. A cosmetic comprising the ultraviolet blocking agent according to claim 1.