JP2003160332A - Li-Al BASED LAMELLAR DOUBLE HYDROXIDE COMPOSITE PARTICLE POWDER AND METHOD FOR PRODUCTION THEREOF - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an Li-Al based lamellar double hydroxide composite particle powder large in plate face diameter, proper in thickness and having ultraviolet absorptivity, and also provide a method for production thereof. <P>SOLUTION: This Li-Al based lamellar double hydroxide composite particle powder comprises a Li-Al based lamellar double hydroxide particle and zirconium hydroxide, and is produced by mixing an anion-containing alkaline aqueous solution, a lithium salt aqueous solution and an aluminum compound capable of forming an aluminum ion, aging the resultant mixed solution to generate a core particle of the Li-Al based lamellar double hydroxide, adding the lithium salt aqueous solution and the above aluminum compound to the core particle- containing aqueous dispersion liquid, and then aging in the presence of a zirconium compound. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention has a large plate surface diameter,
Li having an appropriate thickness and having an ultraviolet absorbing ability
-Al-based layered double hydroxide composite particle powder.

The Li-Al layered double hydroxide composite particle powder according to the present invention can be used as a compounding agent of a chlorine-containing resin and an olefin resin which are required to have weather resistance.

[0003]

2. Description of the Related Art As is well known, there are various compounds other than clay minerals as layered compounds. Among them, layered double hydroxides such as hydrotalcite (Layered Dope) are included.
The double hydroxide) has a structure capable of inserting various ions, molecules and the like between the layers, and thus can exhibit an anion exchange function.

Generally, the structure of hydrotalcite is described in "[M 2 ⁺ _1-x M ³⁺ _x (OH)" as described in the Chemical Society of Japan, 1995 (8), p622-628.
₂ ] _x ⁺ [A ^n- _{x / n} · yH ₂ O] _x ^- where M ²⁺
Is a divalent metal ion such as Mg ²⁺ , Co ²⁺ , Ni ²⁺ , Zn ²⁺ , M ³⁺ is Al ³⁺ , Fe ³⁺ , Cr.
Trivalent metal ions such as ^{3+, A} n-is, ^OH -, C
An anion having a valence of 1 ⁻ , CO ₃ ²⁻ , SO ₄ ^2−, or the like, and x is generally in the range of 0.2 to 0.33. The crystal structure has a laminated structure including a two-dimensional basic layer in which regular octahedral brucite units having a positive charge are arranged and an intermediate layer having a negative charge. It is said that.

Hydrotalcite has been used as an antacid for a long time, but since then, it has been developed into various applications utilizing the anion exchange function. For example, an ion exchange material, an adsorbent, a deodorant, It is used in a wide variety of applications such as stabilizers for resins and rubbers such as polyethylene, polypropylene and vinyl chloride, as well as paints, various catalysts, agricultural films and inks.

In addition, at present when environmental consideration is required, it is desired that the additive used does not contain a toxic metal, so that it is not toxic and stable. It can be said that the compound hydrotalcite can meet such expectations.

[0007] In recent years, hydrotalcites have been synthesized by far more diverse combinations of anions and cations than naturally occurring minerals, and these are collectively called hydrotalcite-like compounds or layered double hydroxides. Has been done.

[0008] These are non-stoichiometric compounds represented by a general formula wider than the above composition formulas, and in the combination of metal ions, in addition to divalent-trivalent, monovalent-trivalent, divalent- Tetravalent,
Bivalent-divalent, trivalent-trivalent, trivalent-tetravalent, etc. are known. A typical monovalent-trivalent combination is a Li-Al-based layered double hydroxide.

The Li-Al-based layered double hydroxide is [Al_Two
Li (OH)₆]_n ⁺X^n-・ MH _TwoExpressed as O. This
X here^n-Represents an n-valent anion, and m ≧ 0.

The crystal structure is defined by Clays and Clay Miners.
als) Volume 30, p180-184. Al is arranged in a Gibbsite structure, and a Li ion occupies the vacancy (Vacancy) of the Al, which is two-dimensional.
Anions are incorporated between the layers to form an ayer and compensate for its charge. X-ray diffraction pattern of hydrotalcite _{(Mg 6 Al 2 (OH)} 16 CO 3 · 4H
₂ O) rather than a 3R type laminated structure shown indicates a 2H type laminated structures. It is also known that Li is regularly arranged in the basic layer containing Li and Al.

The Li-Al-based layered double hydroxide particle powder is used as a stabilizer for chlorine-containing resins by taking advantage of the excellent heat-stabilizing action brought about by its anion-exchange function (JP-A-5-179052). Gazette).

Vinyl chloride resins, which are typical chlorine-containing resins, are excellent in mechanical properties, physical properties, electrical properties, molding processability, etc.
It is used in various applications such as the automobile field. In general,
Vinyl chloride resins are prone to deterioration due to heat and light during molding, which causes problems such as deterioration of mechanical properties of molded products and deterioration of color tone. Further, since it causes discoloration or discoloration when used for a long period of time in a place exposed to sunlight such as a door frame and a window frame, a vinyl chloride resin composition having excellent weather resistance that can be used for outdoor applications is desired. .

To meet such demands, a resin composition has been proposed in which a hydrotalcite compound, an ultraviolet absorber and an organic phosphite compound are mixed in a vinyl chloride resin (Japanese Patent Laid-Open No. 2001-181461, etc.). .

As the ultraviolet absorber, a benzophenone-based, salsylate-based, benzotriazole-based, or cyanoacrylate-based organic ultraviolet absorber is usually used.

Depending on the type of the organic UV absorber, its use is limited because the absorber itself is colored. It has a narrow UV absorption region and volatility during high temperature molding.
It has drawbacks such as poor compatibility, and is expensive.

If the Li-Al layered double hydroxide particles having an excellent heat stabilizing effect also have an ultraviolet absorbing ability, even if the ultraviolet absorber is not blended or the blending amount is reduced. Therefore, the vinyl chloride resin composition can obtain desired weather resistance. Therefore, as a compounding agent for a chlorine-containing resin such as a vinyl chloride-based resin, Li-Al-based layered double hydroxide particle powder having an ultraviolet absorbing ability and excellent weather resistance is required.

On the other hand, since the Li-Al layered double hydroxide particle powder has an infrared absorbing ability, it is blended with an olefin resin and used as a heat retaining agent for agricultural films used for greenhouse cultivation such as houses and tunnels. It is used as (Japanese Patent Laid-Open No. 9-142835).

When the Li-Al layered double hydroxide particle powder is used as a heat retaining agent for agricultural films, the organic ultraviolet absorber is often added to the resin composition. This is because the agricultural film is always exposed to direct sunlight, and therefore weather resistance capable of maintaining characteristics for a long period of time even under direct sunlight is required.

However, in addition to the above-mentioned drawbacks, the organic ultraviolet absorber, when incorporated into an olefin resin, easily bleeds out under outdoor exposure conditions such as agricultural applications, and has long-term weather resistance. It was hard to say enough to hold.

Therefore, as an olefin resin compounding agent, Li-Al layered double hydroxide particle powder having ultraviolet absorbing ability and excellent weather resistance is required.

The Li-Al layered double hydroxide particle powder as a compounding agent for chlorine-containing resin and olefin resin has a large plate surface diameter and an appropriate thickness in consideration of dispersibility when the resin is kneaded. However, in order to produce a Li-Al layered double hydroxide particle powder having a large plate surface diameter and an appropriate thickness, special reaction conditions such as hydrothermal synthesis are required. ing.

The Li-Al layered double hydroxide particles can be produced by reacting a water-soluble lithium salt or lithium hydroxide with a water-soluble aluminum salt in the presence of a water-soluble carbonate and an alkali ( JP-A-5-1790
52), a method of reacting Gibbsite type aluminum hydroxide fine particles with a lithium salt of carbonic acid or a combination of a lithium compound capable of forming lithium carbonate and a carbonate in the presence of water (JP-A-9-142835). Gazette), a lithium salt is used for either one of the alkali metal aluminate and the alkali metal salt and / or alkali metal hydroxide other than the alkali metal aluminate. There is a method of reacting an alkali metal salt other than a metal salt and / or an alkali metal hydroxide in water (JP-A-10-17322).

Further, a method of imparting ultraviolet absorbing ability to the powder by substituting an anion contained in the powder of Li-Al layered double hydroxide particles with an organic anion capable of absorbing ultraviolet (Japanese Patent Laid-Open No. 6- 9358) is known.

[0024]

The Li-Al layered double hydroxide particle powder having a large plate surface diameter, a suitable thickness, an ultraviolet ray absorbing ability and excellent weather resistance is currently the most Although required, Li-Al-based layered double hydroxide particles powder satisfying this requirement have not yet been provided.

That is, according to the production methods of the above publications, Li-Al layered double hydroxide particles having a large plate surface diameter, an appropriate thickness, an ultraviolet absorbing ability, and excellent weather resistance. It is difficult to obtain powder.

Therefore, the present invention aims to obtain a Li-Al-based layered double hydroxide particle powder having a large plate surface diameter, an appropriate thickness, an ultraviolet absorbing ability and an excellent weather resistance. This is a technical issue.

[0027]

The above technical problems can be achieved by the present invention as follows.

That is, the present invention is a Li-Al-based layered double hydroxide composite particle powder comprising a Li-Al-based layered double hydroxide and a zirconium hydroxide, wherein the zirconium content is lithium. Li- which is 0.5 to 30.0 mol% in terms of Zr with respect to the total number of moles of aluminum.
It is an Al-based layered double hydroxide composite particle powder.

Further, in the present invention, the average plate surface diameter is 0.1 to 10.
2.0 μm, thickness is 0.010 to 0.080 μm
The above-mentioned Li-Al-based layered double hydroxide composite particle powder.

In the present invention, an alkaline aqueous solution containing anions, an aqueous lithium salt solution and an aluminum compound capable of forming aluminum ions are mixed to prepare a mixed solution having a pH value in the range of 10 to 14, and then the mixed solution is mixed. 8 solution
Aging is performed in a temperature range of 0 to 105 ° C. to generate core particles of Li—Al-based layered double hydroxide particles, and then an aqueous lithium salt solution and aluminum ions are formed in an aqueous suspension containing the core particles. After adding the obtained aluminum compound,
In the method for producing Li-Al layered double hydroxide particles by aging the pH value in the range of 8 to 14 and the temperature in the range of 60 to 105 ° C, the total number of moles of the total lithium and the total aluminum is On the other hand, 0.5 ~ in Zr conversion
A method for producing a Li-Al-based layered double hydroxide composite particle powder, which comprises allowing 30.0 mol% of a zirconium compound to be present during the aging.

The structure of the present invention will be described in more detail as follows.

First, the Li-Al-based layered double hydroxide composite particle powder according to the present invention will be described.

The Li-Al-based layered double hydroxide composite particle powder according to the present invention is a plate-shaped composite particle powder composed of Li-Al-based layered double hydroxide particles and zirconium hydroxide. .

The Li-Al layered double hydroxide composite particle powder according to the present invention is plate-shaped and has a plate surface diameter of 0.1-2.
The thickness is 0 μm and the thickness is 0.010 to 0.080 μm.

When the plate surface diameter of the Li-Al layered double hydroxide composite particle powder according to the present invention is less than 0.1 μm, the dispersibility when kneading into the resin is insufficient. If it exceeds 2.0 μm, industrial production is difficult.
It is preferably 0.12 to 1.8 μm.

When the thickness of the Li-Al layered double hydroxide particles according to the present invention is less than 0.010 μm, the dispersibility when kneading into the resin is insufficient. If it exceeds 0.08 μm, industrial production is difficult.
It is preferably 0.012 to 0.075 μm.

The BET specific surface area value of the Li-Al layered double hydroxide composite particle powder according to the present invention is preferably 7 to 90 m ² / g, more preferably 7 to 60 m ² / g.

The content of the zirconium hydroxide constituting the Li-Al layered double hydroxide composite particle powder according to the present invention is 0 in terms of Zr with respect to the total number of moles of lithium and aluminum. 5 to 30.0 mol% is preferable,
More preferably, it is 1.0 to 28.0 mol%.

The zirconium hydroxide content is 0.5
If it is less than mol%, the ultraviolet absorbing ability is low, which is not preferable. When it exceeds 30.0 mol%, a large amount of fine particles of zirconium hydroxide are formed to form an aggregate and the dispersibility in the resin decreases, which is not preferable.

The composition of the Li-Al-based layered double hydroxide particles of the Li-Al-based layered double hydroxide composite particles according to the present invention is as follows.

[0041] ^{_{[Al 2 Li (OH) 6}} ] n + X n- · mH 2 O X n-: n -valent anion, m ≧ 0.

The anion ^{(X n-)} are, ^OH not particularly specified -, _CO ^{3 2-} and the like, _preferably, ^{CO 3 2-.}

The ultraviolet absorption capacity of the Li-Al-based layered double hydroxide composite particles according to the present invention is preferably 0.010 or more, more preferably 0. 0, when evaluated by the linear absorption coefficient of ultraviolet rays having a wavelength of 340 nm. It is 015 or more. The linear absorption coefficient of ultraviolet rays was measured by the method described below.

Next, a method for producing the Li-Al-based layered double hydroxide composite particle powder according to the present invention will be described.

The method for producing the Li-Al-based layered double hydroxide composite particle powder according to the present invention comprises mixing an alkaline aqueous solution containing an anion, a lithium salt aqueous solution and an aluminum compound capable of forming aluminum ions to obtain a pH value. Is 1
After preparing a mixed solution in the range of 0 to 14, the mixed solution is mixed with 80
Lithium in an aqueous suspension containing the core particles obtained by the primary reaction, which is aged in the temperature range of ˜105 ° C. to form core particles of Li—Al-based layered double hydroxide composite particles. A salt solution and an aluminum compound capable of forming aluminum ions are added, and the pH value is in the range of 8 to 14 and the temperature is 6
It consists of a secondary reaction that matures in the range of 0 to 105 ° C.
0.5 to 30.0 m in terms of Zr with respect to the total number of moles of lithium and aluminum added in the secondary reaction and secondary reaction
ol% zirconium compound is present during aging.

The zirconium compound may be allowed to exist in the reaction solution during the aging of the primary reaction, the secondary reaction, or the primary reaction and the secondary reaction. The zirconium compound can be added to any one of the anion-containing alkaline aqueous solution, the lithium salt aqueous solution, and the aluminum compound-forming aluminum compound raw material.
Method of adding to mixed solution of next reaction, method of adding during aging of primary reaction, method of adding to reaction solution after completion of primary reaction, method of adding to any of raw materials of secondary reaction, 2
Any method of adding during the aging of the next reaction may be used. Preferably, a method of adding to any of the respective raw materials, a method of adding to a mixed solution of the primary reaction, a method of adding during aging of the primary reaction, a method of adding to a reaction solution in which the primary reaction is completed,
This is a method of adding to any of the raw materials for the secondary reaction. When it is added during the aging of the secondary reaction, it is preferably added by half the aging time.

The alkaline aqueous solution containing anions in the present invention is preferably a mixed alkaline aqueous solution of an aqueous solution containing anions and an alkaline hydroxide solution.

The aqueous solution containing anions is preferably an aqueous sodium carbonate solution.

As the alkali hydroxide aqueous solution, sodium hydroxide aqueous solution is preferable.

As the lithium salt aqueous solution in the present invention, lithium hydroxide, lithium carbonate, lithium chloride, lithium sulfate, lithium acetate, lithium nitrate or the like can be used. Preferred are lithium sulfate and lithium carbonate.

Examples of the aluminum compound in the present invention include aluminum sulfate, aluminum hydroxide, aluminum oxyhydroxide (boehmite), aluminum chloride,
Sodium aluminate, aluminum acetate, aluminum nitrate and the like can be used. Aluminum sulfate and aluminum hydroxide are preferable.

As the zirconium compound in the present invention, zirconium sulfate, zirconium chloride, zirconium oxychloride and the like can be used. Preferred are zirconium sulfate and zirconium oxychloride.

In the first-order reaction, the order of mixing the anion-containing alkaline aqueous solution, the lithium salt aqueous solution and the aluminum compound capable of forming aluminum ions is not particularly limited, and each aqueous solution or compound is mixed at the same time. May be.

When each aqueous solution or compound is added, the aqueous solution or compound may be added at once or continuously.

The concentration of the lithium salt is preferably 0.04 to 1.0 mol / l in the reaction solution obtained by mixing the anion-containing alkaline aqueous solution, the lithium salt aqueous solution and the compound capable of forming aluminum ions in the primary reaction. More preferably 0.05 to 0.9 mol / l, the aluminum compound is preferably 0.08 to 2.0 mol / l, more preferably 0.10 to 1.8 mol / l, and the anion is 0.04 to 1.7 mol. / L is preferable, more preferably 0.05 to 1.5 mol / l, and the aqueous alkali hydroxide solution is preferably 0.5 to 8 mol / l, more preferably 0.8 to 6 mol / l.

The temperature during the aging reaction in the primary reaction was 80.
It is ~ 105 ° C, preferably 85 ~ 105 ° C.
Even when the temperature is lower than 80 ° C., the Li—Al-based layered double hydroxide composite particle powder is produced, but the core particle of the Li—Al-based layered double hydroxide composite particle having a large plate surface diameter and an appropriate thickness is obtained. Can't get If the temperature exceeds 105 ° C, a pressure resistant container such as an autoclave is required, which is not economical.

The pH value during the aging reaction in the primary reaction is 1
It is 0 to 14, preferably 10.5 to 14. p
When the H value is less than 10, the plate surface diameter is large, and the core particles of the Li—Al-based layered double hydroxide composite particles having an appropriate thickness cannot be obtained.

The reaction time of the aging reaction in the primary reaction is 2
~ 24 hours are preferred. When the aging time is less than 2 hours, it is difficult to obtain the core particles of the Li—Al-based layered double hydroxide composite particles having a large plate surface diameter and an appropriate thickness. Aging for more than 24 hours is not economical.

The core particles of the Li-Al-based layered double hydroxide composite particles obtained by the first-order reaction have a plate surface diameter of 0.09 to 1.8.
0 μm is preferable, and the thickness is 0.009 to 0.070 μm.
Is preferred, and the BET specific surface area value is 10 to 110 m ² / g
Is preferred.

In the secondary reaction, the total number of moles of lithium and aluminum added is 0.90 or less with respect to the total number of moles of lithium and aluminum added in the primary reaction. It is preferably 0.85 or less. If it exceeds 0.90, a large amount of fine particles are deposited, the plate surface diameter is large,
Li-Al-based layered double hydroxide composite particles having an appropriate thickness cannot be obtained.

In the secondary reaction, the order of adding the lithium salt aqueous solution and the aluminum compound capable of forming aluminum ions is not particularly limited, and each may be added simultaneously.

When each aqueous solution or compound is added, the aqueous solution or compound may be added all at once or continuously.

The concentration of the lithium salt in the reaction solution obtained by mixing the lithium salt aqueous solution and the aluminum compound capable of forming aluminum ions in the secondary reaction is 0.02 to 0.02.
0.5 mol / l is preferable, and 0.02 is more preferable.
~ 0.45 mol / l, the aluminum compound capable of forming aluminum ions is preferably 0.04 to 1.0 mol / l, and more preferably 0.04 to 0.95 mol / l.
It is l. The total molar ratio (Li / Al) of lithium and aluminum added in the primary reaction and the secondary reaction is 0.48 to
0.75 is preferable.

The total addition amount of the zirconium compound in the primary reaction and / or the secondary reaction is 0.5 to 30.0 mol% with respect to the total number of moles of lithium and aluminum added in the primary reaction and the secondary reaction. It is more preferably 1.0 to 28.0 mol%.

The temperature during the aging reaction in the secondary reaction is 60.
˜105 ° C., preferably 65˜105 ° C.
Even when the temperature is lower than 60 ° C, the Li-Al-based layered double hydroxide composite particle powder is produced, but a Li-Al-based layered double hydroxide composite particle powder having a large plate surface diameter and an appropriate thickness is obtained. Absent. If it exceeds 105 ° C, if it exceeds 105 ° C, a pressure resistant container such as an autoclave is required, which is not economical.

The pH value during the aging reaction in the secondary reaction is 8
It is -14, preferably 8.1-14. When the pH value is less than 8, the plate surface diameter is large and a Li-Al-based layered double hydroxide composite particle powder having an appropriate thickness cannot be obtained.

The reaction time of the aging reaction in the secondary reaction is 2
~ 24 hours are preferred. When the aging time is less than 2 hours, it is difficult to obtain a Li-Al-based layered double hydroxide composite particle powder having a large plate surface diameter and an appropriate thickness. Aging for more than 24 hours is not economical.

It is also possible to carry out a tertiary reaction under the same reaction conditions as the secondary reaction, and further to obtain Li-Al-based layered double hydroxide composite particle powder in which the surfaces of the core particles are coated.

After completion of the secondary reaction, Li-Al type layered double hydroxide composite particles are obtained by washing with water and drying by a conventional method.

The Li-Al layered double hydroxide composite particle powder was heated in air or N ₂ , H ₂ at 120 to 350 ° C.
Decrystallization water treatment may be performed by heating in an atmosphere such as e for 1 to 24 hours.

In the present invention, the Li-Al layered double hydroxide composite particle powder is surface-coated with one or more surface coating agents selected from higher fatty acids, organic silane compounds and rosins. Is also good.

[0072]

BEST MODE FOR CARRYING OUT THE INVENTION A typical embodiment of the present invention is as follows.

The plate surface diameter of the Li-Al-based layered double hydroxide composite particle powder is the average value of the numerical values measured from the electron micrograph.

The particle thickness of the Li-Al-based layered double hydroxide composite particle powder is "X-ray diffractometer RAD-2A (manufactured by Rigaku Denki Co., Ltd.)" (tube: Fe, tube voltage: 40 kV, tube Current: 20mA, Goniometer: Wide-angle goniometer,
Sampling width: 0.010 °, scanning speed: 0.500
° / min, divergence slit: 1 °, scattering slit: 1
, Light receiving slit: 0.30 mm), using Li-A
It is shown by the value calculated using the Scherrer's formula from the diffraction peak curve of the (002) crystal plane of the 1-system layered double hydroxide particles.

The particle powder thus obtained was identified by X-ray diffraction, and the diffraction angle 2θ was 5 to 5 using the X-ray diffractometer.
It was measured at 90 °.

The BET specific surface area value is shown by the value measured by the BET method.

[0077] Among the Li-Al-based layered double hydroxide composite particles, the Li-Al-based layered double hydroxide particles ^{_{[Al a Li b (OH)}} 6] n + X n- · mH 2 O X n ⁻ : N-valent anion, a, b when expressed as m ≧ 0, and zirconium content in the Li—Al-based layered double hydroxide composite particle powder, the powder is dissolved with an acid, “plasma emission spectroscopy Analyzer SPS400
0 (Seiko Denshi Kogyo Co., Ltd.) ”.

The carbon content (% by weight) and the content of the sulfur compound or the sulfate ion when CO ₃ ^{2− was} used as the anion (X ⁿ⁻ ) were measured with a carbon sulfur analyzer: EMIA-2200 (manufactured by HORIBA). did.

The ultraviolet absorbing ability of the Li-Al-based layered double hydroxide composite particle powder was evaluated by the following method.

5.0 g of Li-Al-based layered double hydroxide composite particles powder, 10.0 g of melamine resin (trade name: Super Beckamine J-820, manufactured by DIC), alkyd resin (trade name: Beckol 1307-60-). EL, DIC)
20.0 g, butanol (primary reagent) 0.5 g, xylol (primary reagent) 15.0 g were mixed in the coating composition,
Add 160 g of glass beads and disperse using a paint shaker to make a paint, and then use an applicator (GAP1
00 μm) was applied onto a transparent film to form a coating film. About the obtained coating film, "self-recording photoelectric spectrophotometer U
The light transmittance was measured using "V-2100" (manufactured by Shimadzu Corporation). The linear absorption coefficient of ultraviolet rays having a wavelength of 340 nm was calculated by inserting the value of the above light transmittance into the following formula.

Linear absorption coefficient (μm ⁻¹ ) = [ln (1 / t)] / FT t: Light transmittance at wavelength 340 nm (−) FT: Thickness of coating layer of coating film used for measurement (μm) Line The absorption coefficient represents the absorption capacity of ultraviolet rays per unit film thickness.

<Production Method of Li-Al Layered Double Hydroxide Composite Particle Powder> CO ₃ ²⁻ ion concentration is 0.96 mol /
500 ml of 1 L sodium carbonate aqueous solution and 18.4 mol
/ L sodium hydroxide aqueous solution 402 ml (pH value = 1
4.2) and 500 ml of water are mixed, kept at 60 ° C. and stirred in the reaction vessel. 1.0 mol /
l lithium sulfate aqueous solution 400 ml, 1.0 mol / l
Aluminum sulfate aqueous solution of 800 ml and 0.48 m
A mixed solution with 400 ml of an ol / l zirconium sulfate aqueous solution was added to make the total amount 3.2 l. While stirring the inside of the reaction vessel, the pH value was 13.6 and the mixture was aged at 95 ° C. for 7 hours to form a white precipitate. The obtained Li-Al-based layered double hydroxide core particles had a plate surface diameter of 0.30 μm and a thickness of 0.01.
67 μm, the specific surface area was 35.0 m ² / g. (1
Next reaction)

Then, a mixed solution of 100 ml of a 1.0 mol / l lithium sulfate aqueous solution and 200 ml of a 1.0 mol / l aluminum sulfate aqueous solution was added, and the mixture was further added to 0.4
Add 100 ml of 8 mol / l zirconium sulfate aqueous solution to make the total amount 4.0 l, and p while stirring the inside of the reaction vessel.
After aging at H value of 12.1 and 95 ° C. for 6 hours, a white precipitate was formed (second reaction). The ratio of the total number of moles of lithium and aluminum added in the secondary reaction to the total number of moles of lithium and aluminum added in the primary reaction is 0.25.
Is. The white precipitate was filtered, washed with water, and then dried at 60 ° C. to obtain white particle powder.

As a result of identifying this white particle powder by X-ray diffraction, it was confirmed that it was a composite particle powder composed of a layered double hydroxide and zirconium hydroxide.

The obtained Li-Al layered double hydroxide composite particle powder had an average plate surface diameter of 0.37 μm and a thickness of 0.0.
201 μm, plate ratio 18.4, BET specific surface area value 2
8.6 m ² / g, zirconium content is 7.97 in terms of Zr with respect to the total number of moles of lithium and aluminum.
The linear absorption coefficient of mol%, ultraviolet light with a wavelength of 340 nm is
It was 0.0224 μm ⁻¹ .

[0086]

In the present invention, the important point is that L consisting of Li-Al layered double hydroxide particles and zirconium hydroxide.
The i-Al-based layered double hydroxide composite particle powder has an ultraviolet absorbing ability, and the resin composition obtained by using the Li-Al-based layered double hydroxide composite particle powder has excellent weather resistance. is there.

The reason why the Li-Al-based layered double hydroxide composite particle powder according to the present invention has an ultraviolet absorbing ability is that the hydroxide of zirconium constituting the composite particle powder has an ultraviolet absorbing ability. It is considered to be a thing.

It is known that the zirconium oxide particles themselves serve as a scatterer of ultraviolet rays, thereby exhibiting a function of shielding ultraviolet rays. Li-A according to the present invention
Whether the hydroxide of zirconium constituting the l-type layered double hydroxide composite particle powder acts as a scatterer of ultraviolet rays and shields the ultraviolet rays to reduce the ultraviolet transmittance, or the same as the organic ultraviolet absorber. Although it is not clear whether the ultraviolet transmittance is reduced by the ultraviolet energy absorption effect due to the resonance coupling, the hydroxide of zirconium having the above function is present in the Li-Al-based layered double hydroxide composite particle powder according to the present invention. The present inventor presumes that the uniform distribution on the surface reduces the ultraviolet transmittance and improves the weather resistance.

Further, an important point in the present invention is Li-
Generating core particles of Al-based layered double hydroxide composite particles 1
By carrying out the secondary reaction using the secondary reaction and the aqueous suspension containing the core particles obtained in the primary reaction, a Li-Al-based layered composite having a large plate surface diameter and an appropriate thickness under normal pressure. This is the point where a hydroxide composite particle powder is obtained.

Li having a large plate surface diameter and an appropriate thickness
With respect to the reason why the -Al-based layered double hydroxide composite particle powder is obtained, the present inventor has found that Li- having an appropriate size in the primary reaction.
Core particles of Al-based layered double hydroxide composite particles are produced, and lithium ions and aluminum ions added in the secondary reaction are co-precipitated on the surface of the core particles to make the layered double hydroxide layer topotactic. It is considered that the formation of the coating further promotes the crystal growth of the core particles.

In the present invention, since the zirconium compound is added during the reaction for forming the Li-Al layered double hydroxide particles, the Li-Al layered double hydroxide composite particles of the present invention are constituted. The zirconium hydroxide is attached to the particle surface of the Li-Al-based layered double hydroxide particles in the form of fine particles or uniformly dispersed in the Li-Al-based layered double hydroxide particle powder. It is presumed that the zirconium hydroxide adheres to each other to suppress the aggregation of individual Li-Al-based layered double hydroxide particles, and contributes to the improvement of the dispersibility in the resin. Presumed to be present.

[0092]

EXAMPLES Next, examples and comparative examples will be given.

Examples 1 to 8 and Comparative Examples 1 to 4 The kinds and concentrations of lithium compounds, the kinds and concentrations of aluminum compounds, the concentrations of alkaline aqueous solutions, the aging temperature and the kinds of zirconium compounds, the addition amount and the addition timing were variously changed. Other than that, Li-
An Al-based layered double hydroxide composite particle powder was obtained. Comparative Example 4 is a commercially available Li-Al layered double hydroxide particle powder (plate surface diameter 0.35 μm, thickness 0.0290 μm, plate ratio 12.1, specific surface area 22.6 m ² / g). Mizukarak L (trade name, manufactured by Mizusawa Chemical Co., Ltd.).

The production conditions of the primary reaction (core particles) at this time are shown in Table 1, the characteristics of the core particles of the obtained Li-Al-based layered double hydroxide composite particles are shown in Table 2, and the characteristics of the secondary reaction are shown. The production conditions are shown in Table 3, and various properties of the obtained Li-Al-based layered double hydroxide composite particles and Li-Al-based layered double hydroxide composite particles are shown in Table 4.

[0095]

[Table 1]

[0096]

[Table 2]

[0097]

[Table 3]

[0098]

[Table 4]

[0099]

EFFECT OF THE INVENTION The Li-Al layered double hydroxide composite particle powder according to the present invention has a large plate surface diameter, an appropriate thickness, and an ultraviolet absorbing ability, and therefore has a weather resistance. It is suitable as a compounding agent for the required chlorine-containing resin and olefin resin.

Continued front page    F-term (reference) 4G076 AA10 AA18 AA24 AB06 AB18                       BA11 CA02 DA30                 4J037 AA08 AA24 CA09 CA12 DD05                       EE28 EE43 EE46 EE47 FF02                       FF22

Claims (3)

[Claims] 1. A Li-Al-based layered double hydroxide composite particle powder comprising Li-Al-based layered double hydroxide particles and zirconium hydroxide, wherein the content of the zirconium hydroxide is 1. , Li to Al layered double hydroxide composite particle powder, which is 0.5 to 30.0 mol% in terms of Zr with respect to the total number of moles of lithium and aluminum. 2. The Li—Al-based layered double hydroxide composite according to claim 1, wherein the average plate surface diameter is 0.1 to 2.0 μm and the thickness is 0.010 to 0.080 μm. Particle powder. 3. An alkaline aqueous solution containing anions, an aqueous lithium salt solution and an aluminum compound capable of forming aluminum ions are mixed to form a mixed solution having a pH value in the range of 10 to 14, and the mixed solution is then added to 80 to Alumina capable of forming core particles of Li-Al-based layered double hydroxide particles by aging in a temperature range of 105 ° C, and then forming an aqueous lithium salt solution and aluminum ions in an aqueous suspension containing the core particles. After adding the compound, the pH value is 8 ~ 1
In the method of producing Li-Al-based layered double hydroxide particles by aging in the range of 4, the temperature is in the range of 60 to 105 ° C, in the total number of moles of the total lithium and the total aluminum during the aging. On the other hand, 0.5 ~ in Zr conversion
A method for producing a Li-Al-based layered double hydroxide composite particle powder, wherein 30.0 mol% of a zirconium compound is present.