JP3505627B2 - Zinc phosphate UV absorber and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is applied to glass, cosmetics, resins, fibers, inks, etc. to protect the skin from ultraviolet rays and to prevent the deterioration of materials etc. due to ultraviolet rays. The present invention relates to an agent and a manufacturing method thereof. It has been conventionally known that ultraviolet rays deteriorate resins, paints, inks and the like. Also, recently
It has been pointed out that ultraviolet rays have an adverse effect not only on the skin of the human body but also on general living organisms in particular, and the protection against hard ultraviolet rays has become a major problem since the ozone hole appeared in both polar regions. Under such circumstances, cosmetics, fibers, resins, paints and the like having high ultraviolet blocking performance have been demanded. In order to meet such demands, the present invention intends to provide a new ultraviolet absorber which has a considerable transparency to visible light and selectively absorbs only ultraviolet light, and a method for producing the same. It is a thing.

[0002]

2. Description of the Related Art Organic UV absorbers such as benzoic acid and benzophenone and inorganic UV absorbers such as titanium dioxide and zinc oxide have been known. In addition, recently, inventions relating to various new ultraviolet absorbers have been disclosed. For example, JP-A-3-70776 discloses a resin composition containing cerium-containing zirconia particles, and JP-A-4-279518 discloses a non-swelling fluoromica powder containing a rare earth element. Cosmetics containing the body are disclosed. Also, Japanese Patent Application No. 5-
Japanese Patent No. 25458 discloses an ultraviolet absorber composed of hydroxyapatite supporting zinc or cerium, and Japanese Patent Application Laid-Open No. 5-117508 discloses aluminum oxide and cerium oxide having an average particle diameter of 0.5 μm. A polyester fiber contained is disclosed.
JP-A-132662 discloses an ultraviolet absorber composed of mica coated with mica fine particles containing a heavy metal on the surface.

[0003]

The conventional organic UV absorbers have problems in stability and safety, and the conventional titanium dioxide and zinc UV absorbers have recently been advanced in fine particle formation technology. However, there is still a problem in dispersibility and weather resistance, and its use is limited. Cerium-containing zirconia particles disclosed in JP-A-3-70776 and JP-A-5-
The ultraviolet absorber composed of hydroxyapatite supporting zinc or cerium disclosed in Japanese Patent No. 25458,
All of them are opaque, and when mixed with a resin or the like, there is a problem that it becomes difficult to maintain the transparency, and the invention disclosed in JP-A-5-117508 is limited to polyester fibers and the like. In addition, the non-swelling fluoromica powder containing a rare earth element disclosed in JP-A-4-279518, and JP-A-5-13266.
The mica coated with fine mica particles containing a heavy metal on the surface disclosed in Japanese Patent No. 2 has a scale-like shape and thus has a problem in dispersibility when kneaded into a resin. INDUSTRIAL APPLICABILITY The present invention has high safety and good dispersibility when kneaded into resin, fiber, etc.,
By directly synthesizing transparent crystalline inorganic compound fine particles that are stable over time, these problems are overcome, and there is considerable transparency to visible light, and only ultraviolet rays are selected. To provide a new ultraviolet absorber that absorbs energy and a method for producing the same.

[0004]

In order to solve the above-mentioned problems, the present inventors have proposed lithium, sodium, potassium,
The total amount is 1 to 20 relative to the sparingly soluble zinc phosphate compound consisting of zinc phosphate and one or more phosphates selected from the group consisting of ammonium, calcium, aluminum, magnesium and strontium. Zinc phosphate ultraviolet absorber characterized by supporting cerium or cerium and silver in an amount of 30% by weight (hereinafter referred to as "first invention"), and water-soluble phosphoric acid having a concentration of 30% by weight or more An aqueous solution of a salt requires an oxide, a carbonate, or a hydroxide of at least one selected from the group consisting of lithium, sodium, potassium, ammonium, calcium, aluminum, magnesium, and strontium, and After adding a quantity of zinc oxide, carbonate, or hydroxide and reacting to obtain a highly concentrated slurry of a sparingly soluble zinc phosphate compound A zinc phosphate ultraviolet ray according to the first aspect of the invention, characterized in that cerium or an aqueous solution of a water-soluble salt of cerium and silver is added and cerium or cerium and silver are supported by using a reactor having high miscibility. Provided is a method for producing an absorbent (hereinafter referred to as "second invention").

The poorly soluble zinc phosphate compound in the first invention is, as described in the first half of the second invention, a water-soluble phosphate, for example, a water-soluble phosphate such as lithium, sodium, potassium, ammonium, magnesium, aluminum and zinc. 30% by weight or more, preferably 40 to 6 of the acid phosphate
A 0% by weight highly concentrated aqueous solution containing at least one metal oxide, carbonate, or hydroxide selected from the group consisting of calcium, aluminum, magnesium, and strontium, and the required amount of zinc. It is manufactured by adding and reacting with the oxide, carbonate, or hydroxide. Here, the zinc oxide, carbonate, or hydroxide is limited to a necessary amount because an aqueous solution of a zinc salt such as an aqueous solution of zinc dihydrogen phosphate is used as the water-soluble aqueous solution of phosphate. This is in consideration of the case where the addition of zinc oxide, carbonate or hydroxide is not required. The molar ratio of zinc to the dissimilar metal (Zn / dissimilar metal) is in the range of 1/8 to 20/1,
It is preferable to react in the range of 1/4 to 5/1. The reaction may be either a wet reaction or a dry reaction, but the wet reaction is preferred. As the reactor, it is preferable to use a reactor having a high miscibility. For example, as a reactor, a kneader, an emulsifier, a medium mill is preferably used, and further, a ball mill, a bead mill, a vibration mill or the like having a mechanochemical effect is more preferably used.

To support cerium or silver on the sparingly soluble zinc phosphate compound produced as described above, an aqueous solution of a water-soluble salt of cerium or silver such as cerium nitrate or silver nitrate is added and reacted. Supported, at the time of addition, at the same time as the production of the sparingly soluble zinc phosphate compound, during the production, or
It may be any after production. The supporting reaction of cerium or silver is preferably a wet reaction, similarly to the production of the sparingly soluble zinc phosphate compound, and it is preferable to use a reactor having a high miscibility as a reactor. It is more preferable to use a reactor having a mechanochemical effect.

[0007]

[Function] The zinc phosphate-based ultraviolet absorber according to the present invention,
It is not known in detail what kind of action shows excellent characteristics as an ultraviolet absorber, but it is thought that the following characteristics and actions are involved. Generally, zinc such as zinc phosphate is easy to form a basic salt, has a wide range of crystallinity and is easy to obtain transparency. Therefore, the transparency is maintained even when kneaded into a paint or resin. it is conceivable that. Further, to this zinc phosphate, a compound such as lithium, sodium, potassium, calcium, magnesium, strontium, and aluminum having a high ionization tendency is blended, and a high-concentration slurry is reacted with a highly miscible reactor to react, It is considered that not only it is possible to form a fine refractory salt that is highly dispersible in paints and resins, but also it is possible to firmly support cerium and silver.

[0008]

【Example】

1. Production of Zinc Phosphate Ultraviolet Absorber and the Like [Example 1] 600 g of a 40% sodium dihydrogen phosphate (NaH ₂ PO ₄ ) solution heated to 40 ° C. was put into a Dispermill, and zinc oxide (ZnO) 162.8 g Was gradually dispersed and added to react, and the mixture was stirred for 30 minutes. After cooling the slurry, which had reached 60 ° C. by the reaction, to 30 ° C., cerium nitrate (Ce (NO ₃ ) ₃ 6H ₂ O) 58.
0 g was added and kneaded for 30 minutes for reaction. The reaction slurry is filtered and the resulting filter cake is washed at 250 ° C. for 1 hour.
Dry powder for 0 hours (hereinafter referred to as "UV absorber 1")
Got The cerium content of this ultraviolet absorber 1 was 5% by weight.

Example 2 280 g of a 40% lithium dihydrogen phosphate (LiH ₂ PO ₄ ) solution heated to 50 ° C. was placed in a Futaba kneader, and calcium dihydrogen phosphate (Ca (H
After 126 g of ₂ PO ₄ ) ₂ H ₂ O) was added and dissolved, 200 g of zinc hydroxide (Zn (OH) ₂ ) was gradually added while kneading and reacted. The slurry, which had reached 65 ° C. by the reaction, was kneaded for 1 hour while cooling, then, 33 g of cerium nitrate (Ce (NO ₃ ) ₃ 6H ₂ O) and silver nitrate (AgN
O ₃ ) (5.5 g) was added, and the mixture was further kneaded at 40 ° C. for reaction. The reaction slurry was treated in the same manner as in Example 1 to obtain a powder (hereinafter referred to as "ultraviolet absorber 2"). The UV absorber 2 had a cerium content of 3% by weight and a silver content of 1% by weight.

Example 3 2 l of 400 ml of water at 20 ° C.
Put in an alumina ball mill, and further, ammonium dihydrogen phosphate (NH ₄ H ₂ PO ₄ ) 287.6 g, zinc oxide (ZnO) 142.5 g, aluminum hydroxide (gibbsite Al ₂ O ₃ 3H ₂ O) 39.0 g. , And 90.9 g of cerium nitrate (Ce (NO ₃ ) ₃ 6H ₂ O) were added, and the mixture was kneaded for 20 hours for reaction. Reaction slurry is 25 ℃
Had reached. The reaction slurry was treated in the same manner as in Example 1 to obtain a powder (hereinafter referred to as "ultraviolet absorber 3"). The cerium content of this ultraviolet absorber 3 was 7% by weight.

Example 4 518.8 g of a 50% zinc dihydrogen phosphate (Zn (H ₂ PO ₄ ) ₂ ) solution at 20 ° C. was added to 3 parts.
l Place in a bead mill and strontium carbonate (SrC
34 4.4 g of powder of O ₃ ) was added and kneaded to react. 300 ml of water and 145.5 g of cerium nitrate (Ce (NO ₃ ) ₃ 6H ₂ O) were added to the slurry that had reached 30 ° C.
Was added, and the mixture was further kneaded for 1 hour for reaction. The reaction slurry was treated in the same manner as in Example 1 to obtain powder (hereinafter referred to as “UV absorber 4”).
I got). The cerium content of this ultraviolet absorber 4 was 10% by weight.

Example 5 A 60% magnesium dihydrogen phosphate (Mg (H ₂ PO ₄ ) ₂ ) solution at 30 ° C. 363.8
g was placed in a Dispermill, 77.9 g of 48% potassium hydroxide (KOH) was added while cooling, and 162.8 g of zinc oxide (ZnO) was gradually added to form a slurry, and then cerium nitrate (Ce (NO _{3) 3 6H 2 O) 23} .
5 g and 11.7 g of silver nitrate (AgNO ₃ ) were added, and the mixture was kneaded for 60 minutes for reaction. The reaction slurry having reached 35 ° C. was treated in the same manner as in Example 1 to obtain a powder (hereinafter referred to as “ultraviolet absorber 5”). The UV absorber 5 had a cerium content of 2% by weight and a silver content of 2% by weight.

Comparative Example For comparison, a commercially available zinc oxide powder was used as the ultraviolet absorber 6 and a commercially available rutile titanium dioxide powder was used as the ultraviolet absorber 7.

2. UV Absorption Test 20 g each of the UV absorbers 1 to 5 obtained in Examples 1 to 5 and the UV absorbers 6 and 7 obtained in Comparative Examples
For, since the absorption of visible light is high,
4 g of water-soluble epoxy ester resin (Watersol CD-540 manufactured by Dainippon Ink and Chemicals, Inc.) 200
g and 100 g of glass beads (Φ1.5 mm) were dispersed in a sand mill for 10 minutes. Each of the obtained dispersions was applied on a transparent quartz plate to a thickness of 20 μm, and the light transmittance was measured with a spectrophotometer. The result is shown in Figure 1.
It was shown to. In this figure, the horizontal axis represents the wavelength of transmitted light (n
m), and the vertical axis represents the light transmittance. The numbers attached to the curves represent the ultraviolet absorbers 1 to 7, and B represents the transmittance when only the water-soluble epoxy ester resin was applied to the transparent quartz plate to a thickness of 20 μm.

As shown in FIG. 1, the zinc oxide shown in the ultraviolet absorber 6 already has a considerably low transmittance for visible light (400 to 800 nm), and likewise, it does not emit ultraviolet light (400 nm or less). It also has a low transmittance and does not appear to selectively absorb UV light. Further, it can be recognized that the titanium dioxide shown in the ultraviolet absorber 7 also has a considerably low transmittance for visible light and has a slight selective absorption of ultraviolet light. Not too much. In contrast to these comparative examples, all of the ultraviolet absorbers 1 to 6 according to the present invention have a considerably high transmittance for visible light, whereas they have a low transmittance for ultraviolet rays. It can be seen that UV rays are selectively absorbed.

[0016]

EFFECT OF THE INVENTION The zinc phosphate ultraviolet absorber according to the present invention has the structure and action as described above, and therefore is safe for human body and has good dispersibility even when kneaded into resin. It is a fine powder that is highly stable and chemically stable, and has a high transmittance for visible light, but it has the property of selectively absorbing ultraviolet light. It brings about an effect that it can be used as an ultraviolet absorber in a wide range including necessary uses. Further, the method for producing a zinc phosphate-based ultraviolet absorber according to the present invention brings the effect of enabling the production of such an excellent ultraviolet absorber for the first time.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the light wavelength and the transmittance of an ultraviolet absorber and another ultraviolet absorber according to an example of the present invention.

Claims (2)

(57) [Claims] 1. Lithium, sodium, potassium, ammonium, calcium, aluminum, magnesium,
And cerium in a total amount of 1 to 20% by weight with respect to the sparingly soluble zinc phosphate compound consisting of zinc phosphate and one or more kinds of phosphate selected from the group consisting of strontium or Zinc phosphate UV absorber characterized by supporting cerium and silver 2. One or more selected from the group consisting of lithium, sodium, potassium, ammonium, calcium, aluminum, magnesium, and strontium in an aqueous solution of a water-soluble phosphate having a concentration of 30% by weight or more. Oxides, carbonates, or hydroxides of the above, and a necessary amount of zinc oxide, carbonate, or hydroxide are added and reacted to form a highly concentrated slurry of a sparingly soluble zinc phosphate compound. After obtaining, cerium or an aqueous solution of a water-soluble salt of cerium and silver is added, and cerium or cerium and silver are supported by using a reactor having high miscibility.
Method for producing zinc phosphate-based ultraviolet absorber described in