JP2000290451A - Mg-al-based hydrotalcite type particle powder, stabilizer for chlorine-containing resin and production of the same powder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain Mg-Al-based hydrotalcite type particle powder having a large plate surface diameter and appropriate thickness, and suitable as a stabilizer for a chlorine-containing resin. SOLUTION: This Mg-Al-based hydrotalcite type particle powder having a large plate surface diameter and suitable thickness, and suitable as a stabilizer for a chlorine-containing resin, has 0.1-1.0 μm plate surface diameter and 0.02-0.08 μm thickness, contains 0.0010-0.0080 molar ratio of zinc based on the total number of moles of Mg and Al, and exhibits >=4 hr heat resistant time in the case of heating a resin sheet prepared by mixing 3 pt.wt. particle powder with 100 pts.wt. vinyl chloride resin at 180 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a large plate surface diameter,
An object of the present invention is to provide Mg-Al-based hydrotalcite-type particles having an appropriate thickness and suitable as a stabilizer for a chlorine-containing resin.

[0002]

2. Description of the Related Art As is well known, various compounds other than clay minerals are present in layered compounds. Among them, layered double hydroxides such as hydrotalcite are known.
bleHydroxide) has a structure in which various ions and molecules can be inserted between layers, so that it can exhibit an anion exchange function.

[0003] Generally, the structure of hydrotalcite is
Described in the journal of the Chemical Society of Japan, 1995 (8), pp. 622-628.
As mentioned, "[M²⁺ _1-xM³⁺ _x(OH)₂]_x ⁺[An⁻
_{x / n}・ YH₂O]_x ⁻  Where M²⁺Is Mg²⁺, Co²⁺, Ni²⁺, Zn
²⁺Divalent metal ions such as M³⁺Is Al³⁺, Fe
³⁺, Cr³⁺Trivalent metal ions such as An⁻Is OH
⁻, Cl⁻, CO₃ ^2-, SO₄ ^2-N-valent shades such as
On, x typically ranges from 0.2 to 0.33. Conclusion
The crystal structure is composed of a positively charged octahedral brucite unit.
It consists of a two-dimensional base layer in which
It has a laminated structure. "It is.

[0004] Hydrotalcite has been used for various applications utilizing its anion exchange function, for example, as an ion exchange material, an adsorbent, a deodorant and the like. In addition, it is used in a wide variety of applications such as resins, rubber stabilizers such as polyethylene, polypropylene, and chlorine-containing resins (typically, vinyl chloride resin), as well as paints, various catalysts, agricultural films, and inks. .

Particularly, among the hydrotalcite-type particles, Mg-Al-based hydrotalcite-type particles having Mg ^{2 + as} a divalent metal ion and Al ^{3 +} as a trivalent metal ion are stable, It is the one that has received the most attention. Examples of the hydrotalcite-type particle powder include an iron-based hydrotalcite-type particle powder (Japanese Patent Application Laid-Open No. 9-227127). However, since it has iron, it is colored when kneaded into a resin. It is difficult to say that the heat resistance is sufficient when used as a stabilizer for a chlorine-containing resin as compared with a Mg-Al-based hydrotalcite-type particle powder.

As a method for producing hydrotalcite, an aqueous metal salt solution containing a divalent metal ion and a trivalent metal ion constituting a basic layer and a carbonate aqueous solution containing a carbonate ion constituting an intermediate layer are mixed. In general, a method of controlling the temperature, pH value, and the like to obtain by coprecipitation reaction is used. In addition to the reaction under normal pressure, a method is also known in which the reaction is obtained by a hydrothermal reaction using an autoclave.

Conventionally, as a hydrotalcite-type particle powder for kneading resin, a particle powder having a large plate surface diameter and an appropriate thickness has been required in consideration of dispersibility at the time of kneading the resin. To produce hydrotalcite-type particles having a large plate surface diameter, special reaction conditions such as hydrothermal synthesis are required.

When hydrotalcite-type particle powder is used as a stabilizer for a resin or rubber containing chlorine such as a vinyl chloride resin, in order to obtain a resin or rubber product having excellent heat resistance, it is necessary to use a resin or rubber. It is required to be sufficiently dispersed and to have a higher ability to capture chloride ions.

[0009]

SUMMARY OF THE INVENTION Mg, which has a large plate surface diameter and an appropriate thickness, is suitable as a stabilizer for chlorine-containing resin.
-Al-based hydrotalcite-type particle powders are the most demanded at present.
g-Al-based hydrotalcite-type particles have not yet been obtained.

In other words, the conventional method based on the coprecipitation reaction cannot obtain hydrotalcite-type particle powder having a large plate surface diameter, and has a large plate surface diameter under special reaction conditions such as hydrothermal synthesis. Although hydrotalcite-type particle powder can be obtained, the heat resistance of a chlorine-containing resin using the particle powder as a stabilizer is not sufficient.

An object of the present invention is to obtain Mg-Al-based hydrotalcite-type particles having a large plate surface diameter and an appropriate thickness and suitable as a stabilizer for a chlorine-containing resin.

[0012]

The above technical object can be achieved by the present invention as described below.

That is, according to the present invention, the plate surface diameter is 0.1 to 1.0.
μm, the thickness is 0.02 to 0.08 μm,
Zinc is added in a molar ratio of 0.1 to the total number of moles of Mg and Al.
Mg-Al based high containing 0010-0.0080
Drotalsite type particle powder, wherein the particle powder is as follows:
The heat resistance time measured by the measurement method must be 4 hours or more
Characteristic Mg-Al-based hydrotalcite-type particle powder
(Invention 1). Hydrotalcite-type particle powder in vinyl chloride resin
And additives are mixed in the following composition ratio, and the resulting mixture 5
0 g is kneaded using a hot roll, and the kneaded sheet is kneaded.
Obtained. The kneading conditions were as follows: kneading temperature 155 ° C, roll
The gap is 0.75 mm and the kneading time is 3 min. Hydrotalcite-type particle powder: 3 parts by weight, vinyl chloride resin (degree of polymerization: 1300) (trade name: TK-1300, manufactured by Shin-Etsu Chemical): 100 parts by weight, diethylhexyl phthalate (DOP, manufactured by Daihachi Chemical): 50 Parts by weight, calcium stearate (primary reagent): 2 parts by weight, zinc stearate (primary reagent): 0.4 parts by weight, 1,3 diphenyl-1,3 propanedione (primary reagent): 0.2 parts by weight, Diethyl phosphate (primary reagent): 0.5 parts by weight. The obtained kneaded sheet is subjected to pressure treatment with a hot press,
Sheet pieces (thickness 1.5 mm) were prepared. Pressurization condition is
Press temperature 160 ° C, press pressure 100kg / cm ²,
Less time 1 minute, press gap 1.5mm, processing amount 35g
is there. The obtained sheet piece (20 mm × 20 mm) is placed in air 1
Place in an 80 ° C. oven and perform heat resistance test. Sheet pieces
The time during which the entire surface turned black is defined as the heat resistance time.

The present invention also relates to the Mg-Al hydrotalcite-type particles of the present invention coated with a hydroxide of silicon or a silicon oxide or a silicon hydroxide and a silicon oxide. Then, the particle powder of the present invention 1
A Mg—Al-based hydrotalcite-type particle powder characterized by having a heat resistance time of 4 hours or more as measured by the measurement method (Invention 2).

Further, the present invention is a chlorine-containing resin stabilizer comprising the Mg-Al-based hydrotalcite-type particles of the present invention 1 or 2.

In the present invention, an alkaline aqueous solution containing anions, an aqueous magnesium salt solution and an aqueous aluminum salt solution are mixed, and the mixed solution is added in a molar ratio of 0.02 to 0 with respect to the total mole number of Mg and Al. 0.25 aqueous zinc salt solution, pH value is 10-14, 60-105
M of the invention 1 characterized by aging in a temperature range of ° C.
This is a method for producing g-Al-based hydrotalcite-type particles.

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

First, the Mg-Al-based hydrotalcite-type particles according to the present invention will be described.

The Mg-Al-based hydrotalcite-type particles according to the present invention are plate-like and have a plate surface diameter of 0.1 to 0.1.
1.0 μm, and the thickness is 0.02 to 0.08 μm.

When the plate surface diameter of the Mg-Al-based hydrotalcite-type particles according to the present invention is less than 0.1 μm,
Dispersibility upon kneading into resin is insufficient. 1.0 μm
When it exceeds, it is difficult to produce industrially. Preferably it is 0.2 to 0.8 μm.

When the thickness of the Mg—Al hydrotalcite type particles according to the present invention is less than 0.02 μm,
Dispersibility upon kneading into resin is insufficient. 0.08μ
If it exceeds m, it is difficult to produce industrially. Preferably it is 0.025 to 0.075 μm.

The Mg-Al-based hydrotalcite-type particles according to the present invention contain zinc in a molar ratio of 0.0010 to 0.0080 with respect to the total number of moles of Mg and Al.
Preferably, it contains 0.0010 to 0.0070.

In the case where the zinc content of the Mg-Al-based hydrotalcite-type particles according to the present invention is less than 0.0010 in a molar ratio with respect to the total number of moles of Mg and Al, and 0.
If it exceeds 0080, the plate surface diameter of the Mg-Al-based hydrotalcite-type particles cannot be sufficiently increased.

The Mg-Al-based hydrotalcite-type particle powder according to the present invention is characterized in that the particle powder
The heat resistance time when a resin sheet prepared by mixing 3 parts by weight with respect to parts by weight and heated at 180 ° C. is 4 hours or more.

When the heat resistance time is less than 4 hours, the heat resistance of the chlorine-containing resin cannot be said to be sufficient when used as a stabilizer. Preferably it is for 5 to 16 hours.

The composition formula of the Mg—Al-based hydrotalcite-type particles according to the present invention is as follows.

[Mg _x Zn _y ] · Al _z. (OH) _2.
An ^- _p · mH ₂ O 0.2 ≦ z / (x + z) ≦ 0.6, 0.0010 ≦ y / (x + z) ≦ 0.0080, x + y + z = 1 p = (2 (x + y−1) + 3z) / N, A: n-valent anion, m> 0.

The Mg-Al content ratio of the Mg-Al-based hydrotalcite-type particles according to the present invention is expressed by Al /
When (Mg + Al) = z / (x + z), z /
(X + z) is 0.2 to 0.6. When z / (x + z) is less than 0.2 (Mg: Al = 4: 1) and more than 0.6 (Mg: Al = 2: 3), the single phase of the hydrotalcite-type particles is It is difficult to obtain. z / (x +
The preferred range of z) is 0.2 to 0.56.

The sum of x, y and z is 1.

The types of anions (A ⁿ⁻ ) contained in the Mg—Al-based hydrotalcite-type particles according to the present invention include a hydroxyl ion (OH ⁻ ) and a carbonate ion (CO ₃ ).
^2- ) and sulfate ion (SO ₄ ^2- ), and particularly preferably a carbonate ion.

The Mg—Al-based hydrotalcite-type particles according to the present invention have a plate-like ratio (plate diameter / thickness) of 2 to 15%.
Is more preferably 2 to 13, the BET specific surface area value is preferably 8 to 90 m ² / g, more preferably 8 to 70 m ² / g, and the powder pH value is 9.0 to 1
1.0, more preferably 9,0 to 10.5.

The Mg-Al-based hydrotalcite-type particle powder according to the present invention has a particle surface coated with a silicon hydroxide or a silicon oxide or a silicon hydroxide and a silicon oxide as required. You may. When the Mg-Al-based hydrotalcite-type particles coated with the silicon compound according to the present invention are used as a chlorine-containing resin stabilizer, the ability to more uniformly disperse in the chlorine-containing resin and to capture chlorine ions is improved. Further, the stability and heat resistance of the resin are further improved.

The coating amount of the surface of the Mg-Al hydrotalcite-type particles according to the present invention with the hydroxides of silicon is 0 in terms of SiO _{2 with} respect to the Mg-Al-type hydrotalcite-type particles. It is preferably 0.05 to 50% by weight, more preferably 0.05 to 45% by weight. When the coating amount of the silicon compound is less than 0.05% by weight, the effect of coating with the silicon compound cannot be obtained. If it exceeds 50% by weight, the coating effect is saturated, so that there is no point in coating more than necessary.

The Mg-Al-based hydrotalcite-type particles which are surface-coated with a hydroxide of a silicon compound or the like according to the present invention are the same as the Mg-Al-based hydrotalcite-type particles which are not surface-coated.
It has a plate surface diameter, a thickness, a plate ratio, and a BET specific surface area value that are almost the same as those of the Al-based hydrotalcite-type particles.

The Mg-Al-based hydrotalcite-type particle powder surface-coated with a hydroxide of a silicon compound according to the present invention preferably has a powder pH value of 8.0 to 10.5, more preferably. 8.0 to 10.0, and the powder pH value is lower than that of the Mg-Al-based hydrotalcite-type particle powder according to the present invention, which is not surface-coated.

The Mg-Al-based hydrotalcite-type particle powder surface-coated with a hydroxide of silicon or the like according to the present invention was prepared by mixing 3 parts by weight of the particle powder with 100 parts by weight of vinyl chloride resin. Heat resistance time when the resin sheet is heated at 180 ° C. is 4 hours or more. More preferably, it is 5 to 20 hours.

When the Mg-Al-based hydrotalcite-type particles according to the present invention or the Mg-Al-based hydrotalcite-type particles whose surface is coated with a silicon compound are used as the chlorine-containing resin stabilizer, the mixing ratio is as follows. The Mg-Al-based hydrotalcite-type particle powder is 0.5 to 10 parts by weight with respect to 100 parts by weight of the contained resin. When the mixing ratio is less than 0.5 parts by weight, the effect of improving the heat resistance of the resin cannot be expected. When the mixing ratio is more than 10 parts by weight, the effect of improving the heat resistance is saturated, so that it is meaningful to add more than necessary. Absent. Preferably it is 1 to 6 parts by weight.

Next, a method for producing the Mg-Al-based hydrotalcite-type particles according to the present invention will be described.

The Mg-Al-based hydrotalcite-type particles according to the present invention are obtained by mixing an alkaline aqueous solution containing anions, a magnesium salt aqueous solution and an aluminum salt aqueous solution, adding a zinc salt aqueous solution to the mixed aqueous solution, and adding a pH value. Can be obtained by aging in a temperature range of 10 to 14, 60 to 105 ° C for 2 to 24 hours.

As the alkaline aqueous solution containing an anion in the present invention, a mixed alkaline aqueous solution of an aqueous solution containing an anion and an aqueous alkali hydroxide solution is preferable.

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

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

As the aqueous magnesium salt solution in the present invention, an aqueous solution of magnesium sulfate, an aqueous solution of magnesium chloride, an aqueous solution of magnesium nitrate and the like can be used, and an aqueous solution of magnesium sulfate and an aqueous solution of magnesium chloride are preferred.

As the aluminum salt aqueous solution in the present invention, an aluminum sulfate aqueous solution, an aluminum chloride aqueous solution, an aluminum nitrate aqueous solution and the like can be used, and an aluminum sulfate aqueous solution and an aluminum chloride aqueous solution are preferable.

As the aqueous zinc salt solution in the present invention, an aqueous zinc sulfate solution, an aqueous zinc chloride solution, an aqueous zinc nitrate solution and the like can be used, and an aqueous zinc sulfate solution and an aqueous zinc chloride solution are preferable.

The order of mixing the aqueous alkali solution, the aqueous magnesium salt solution, the aqueous aluminum salt solution and the aqueous zinc salt solution containing an anion is not particularly limited, and the aqueous solutions may be mixed simultaneously. Preferably, an aqueous solution in which an aqueous solution of a magnesium salt, an aqueous solution of an aluminum salt, and an aqueous solution of a zinc salt are mixed in advance is added to the aqueous alkali solution containing anions.

When each aqueous solution is added, the aqueous solution may be added at once, may be added in two or more portions, or may be added continuously.

The amount of the zinc salt aqueous solution to be added is 0.02 to 0.25, preferably 0.03 to 0.20, in a molar ratio to the total number of moles of Mg and Al.

In the present invention, the concentration of the magnesium salt in the reaction solution obtained by mixing the aqueous alkali solution, the aqueous magnesium salt solution, the aqueous aluminum salt solution and the aqueous calcium salt solution containing the anion is preferably 0.1 to 1.5 mol / l. Preferably, 0.1 to 1.2 mol / l, and the aluminum salt is preferably 0.03 to 1.0 mol / l,
More preferably, 0.04 to 0.8 mol / l, the zinc salt is preferably 0.002 to 0.25 mol / l, more preferably 0.002 to 0.20 mol / l, and the anion is 0.05 to 1 It is preferably 0.4 mol / l, more preferably 0.06 to 1.2 mol / l, and the alkali hydroxide aqueous 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 present invention is 60 to
The temperature is 105 ° C, preferably 80 to 105 ° C. 6
When the temperature is lower than 0 ° C., hydrotalcite-type particle powder is generated, but hydrotalcite-type particle powder having a large plate surface diameter cannot be obtained. If the temperature exceeds 105 ° C,
A pressure vessel such as an autoclave is required, which is not economical.

In the present invention, the pH value during the aging reaction is 10
To 14, preferably 11 to 14. If the pH value is less than 10, a hydrotalcite-type particle powder having a large plate surface diameter and an appropriate thickness cannot be obtained.

The reaction time of the aging reaction in the present invention is 2 to 2.
24 hours is preferred. When the aging time is less than 2 hours, it is difficult to obtain a hydrotalcite-type particle powder having a large plate surface diameter and an appropriate thickness. Aging beyond 24 hours is not economical.

After completion of the aging reaction, washing with water and drying by a conventional method yields Mg-Al hydrotalcite-type particles.

Next, in the surface coating treatment of the Mg-Al-based hydrotalcite-type particles coated with the hydroxide of silicon or the like, the Mg-Al-based hydrotalcite-based particles according to the present invention are dispersed. To the obtained aqueous suspension, a silicon compound is added to adjust the temperature of the aqueous suspension to 20 to 90 ° C., and the mixture is stirred and mixed. By adjusting
-The particle surface of the Al-based hydrotalcite type particle powder,
Coated with silicon hydroxide or silicon oxide or silicon hydroxide and silicon oxide, followed by filtration,
Wash, dry and crush.

As the silicon compound, No. 3 water glass, sodium orthosilicate, sodium metasilicate, colloidal silica and the like can be used. Preferred is No. 3 water glass.

The addition amount of the silicon compound is 0.05 to 50.00% by weight in terms of SiO ₂ with respect to the Mg—Al-based hydrotalcite-type particles. If the content is less than 0.05% by weight, it is difficult to coat the surface of the particles with a sufficient amount of silicon hydroxide or the like. 50.00% by weight
If it exceeds 3, the coating effect is saturated, and there is no point in adding more than necessary.

The Mg-Al-based hydrotalcite-type particles in which the surface of the particles is coated with a hydroxide of silicon or the like are prepared from a higher fatty acid such as stearic acid or oleic acid, a silane-based coupling agent, Further coating may be performed using a system coupling agent, rosin, or the like.

[0058]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A typical embodiment of the present invention is as follows.

The plate surface diameter of the hydrotalcite-type particles is represented by the average value of the values measured from an electron micrograph.

The thickness of the particles of the hydrotalcite-type particles is determined by using an X-ray diffractometer RAD-2A (Rigaku Corporation).
(Tube: Fe, tube voltage: 40 kV, tube current: 20)
mA, goniometer: wide-angle goniometer, sampling width: 0.010 °, scanning speed: 0.5 ° / min,
(Divergence slit: 1 °, scattering slit: 1 °, light receiving slit: 0.30 mm), and the value calculated using the Scherrer equation from the diffraction peak curve of the (003) crystal plane of the hydrotalcite particles. It is a thing.

The identification of the hydrotalcite type particle powder is X
It was performed by a line diffraction measurement. The X-ray diffraction measurement was performed using the X-ray diffractometer at a diffraction angle 2θ of 5 to 90 °.

Composition formula [Mg _x Zn _y ] · Al _z · (OH) ₂ · A ⁿ _-p · m in Mg-Al type hydrotalcite type particle powder
The indices x, y, and z in H ₂ O were determined by dissolving Mg-Al-based hydrotalcite-type particles with an acid, and measuring with a “plasma emission spectrometer SPS4000 (Seiko Instruments Inc.)”. .

Note that CO _{3 is used} as an anion (A ⁿ⁻ ).
^2- The carbon content (% by weight) when used is
Sulfur analyzer: EMIA-2200 (HOR
IBA).

The amount of Si present on the surface of the Mg—Al-based hydrotalcite-type particles was determined according to JIS using “X-ray fluorescence spectrometer 3063M (manufactured by Rigaku Corporation)”.
The measurement was performed in accordance with K0119 “General rules for X-ray fluorescence analysis”.

The powder pH value was determined by weighing 5 g of a sample into a 300 ml Erlenmeyer flask, adding 100 ml of boiled pure water, heating and maintaining the state of boiling for about 5 minutes, then stoppering and allowing to cool to room temperature. Then, after adding water corresponding to the weight loss, stoppering again, shaking for 1 minute, and allowing to stand for 5 minutes, the pH value of the obtained supernatant was measured according to JIS Z 8802-7, and the obtained value was measured. The powder pH value was taken.

The heat resistance time of the Mg—Al hydrotalcite-type particles in the vinyl chloride resin was evaluated by the above method.

<Production of Mg-Al-based hydrotalcite-type particle powder> The CO ₃ ^2- ion concentration was 0.875 mol.
/ Ml of sodium carbonate aqueous solution 500ml and 5.308m
ol / l sodium hydroxide aqueous solution 3 l (pH = 1
4.2) is mixed, kept at 60 ° C. and stirred in the reaction vessel. A mixed solution of 500 ml of 3.75 mol / l magnesium sulfate aqueous solution and 500 ml of 0.625 mol / l aluminum sulfate aqueous solution was added thereto,
200 ml of a 0.75 mol / l aqueous solution of zinc sulfate was added to make the total amount 5 l. PH while stirring inside the reaction vessel
Aged at 95 ° C. for 18 hours with a value of 12.4 to produce a white precipitate. The white precipitate was filtered, washed with water, and dried at 60 ° C. to obtain a white particle powder. As a result of identifying the white particle powder, it was confirmed that the white particle powder was hydrotalcite-type particle powder.

The obtained Mg-Al-based hydrotalcite-type particles have an average plate surface diameter of 0.30 μm and a thickness of 0.3 μm.
0510 μm and a BET specific surface area of 14.6 m ² /
g, powder pH value was 9.3.

3 parts by weight of the above-mentioned Mg—Al-based hydrotalcite-type particles were mixed in the above composition ratio to prepare a kneaded sheet. The heat resistance time at 180 ° C. of the obtained sheet piece was 6 hours.

[0070]

An important point in the present invention is that a specific amount of an aqueous solution of a zinc salt is added in a coprecipitation reaction to obtain a Mg-Al-based hydrotalcite-type particle powder having a large plate surface diameter and an appropriate thickness under normal pressure. Is obtained.

The reason why Mg-Al-based hydrotalcite-type particles having a large plate surface diameter can be obtained is not yet known.
The present inventor has found that by adding a zinc salt aqueous solution, zinc having a large ionic radius becomes a Mg—Al layer (bruc
By penetrating into the network of the (item layer),
It is thought that the crystal structure distortion caused by aluminum having a small ionic radius is eliminated and crystal growth is promoted.

Further, the journal of the Chemical Society of Japan, 1997 (7), p.
As described in 502 to 507, when an organic anion is added to layered zinc hydroxide by a coprecipitation method, a crosslinked layered hydroxide is generated in which an organic anion is directly coordinated with zinc ion and cross-linked by interlayer, and a crystal is formed. It becomes particles with high properties. In the present invention, the anions (hydroxyl ions, carbonate ions, sulfate ions, etc.) introduced into the hydrotalcite-type particle powder are not organic anions, but act in a similar manner in the c-axis direction (the thickness direction of the plate-like particles). It is thought that it promotes the crystal growth of ()).

When the Mg-Al-based hydrotalcite-type particles according to the present invention are used for kneading a resin such as a chlorine-containing resin, the reason why the heat resistance is improved is that the present inventor proposes that the brucite layer has a zinc layer. By taking into account, the hydrotalcite-type particle powder has a higher chloride ion trapping ability, and the ability to trap unstable chloride ions in the chlorine-containing resin has been increased. We believe that the stability will improve and the heat resistance will also improve.

The Mg-Al-based hydrotalcite-type particles having a particle surface coated with a silicon hydroxide or a silicon oxide or a silicon hydroxide and an oxide according to the present invention may be made of a resin such as a chlorine-containing resin. As a reason for further improving heat resistance when used for kneading, the present inventor has found that the dispersibility of hydrotalcite-type particles in a resin is improved, and that the powder is more uniformly dispersed in a chlorine-containing resin. We believe that the synergistic effect resulting from the improved ability to trap unstable chlorine ions in the chlorine-containing resin will improve the stability and heat resistance of the resin. Also,
It is believed that the coating reduces the surface basicity of the Mg-Al-based hydrotalcite-type particles, thereby suppressing the decomposition of the resin and improving the stability and heat resistance of the resin.

[0075]

Next, examples and comparative examples will be described.

Examples 1 to 8 and Comparative Examples 1 to 6 The type and concentration of magnesium compound, the type and concentration of aluminum compound, the concentration of sodium carbonate, the concentration of aqueous alkali solution, the amount of zinc salt added and the ripening temperature varied. Other than that, Mg-A was used in the same manner as in the embodiment of the invention.
1-type hydrotalcite-type particle powder was obtained. In Comparative Example 6, Mg-Al-based hydrotalcite-type particles were obtained using an autoclave.

Example 9 A suspension (concentration: 56.7 g / l) containing the Mg—Al-based hydrotalcite-type particles obtained in Example 1 was heated to 70 ° C. to make No. 3 water glass. 8.9 g was gradually added, and after the addition was completed, the mixture was aged for 60 minutes. Next, the resultant was filtered, washed with water, dried and pulverized to obtain a Mg-Al-based hydrotalcite-type particle powder whose particle surface was coated with a hydroxide of silicon or the like.

Examples 10 and 11 In the same manner as in Example 9 except that the addition amount of the Mg-Al-based hydrotalcite-type particle powder and No. 3 water glass was changed, the surface of the particles was changed to silicon hydroxide or the like. Mg-coated with
An Al-based hydrotalcite-type particle powder was obtained.

The production conditions at this time are shown in Tables 1 and 2, and various properties of the obtained Mg-Al-based hydrotalcite-type particles are shown in Table 3.

[0080]

[Table 1]

[0081]

[Table 2]

[0082]

[Table 3]

[0083]

The Mg-Al-based hydrotalcite-type particles according to the present invention have a large plate surface diameter, an appropriate thickness, and excellent heat resistance when kneaded into a chlorine-containing resin. It is suitable as a stabilizer for chlorine-containing resins.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08K 5/524 C08K 5/524 9/02 9/02 (72) Inventor Akinori Yamamoto Naka-ku, Hiroshima-shi, Hiroshima 4-1-2, Funeru Minami 4-chome Toda Kogyo Co., Ltd. Creative Center F-term (reference) 4J002 BD041 DE286 EG038 EG048 EH147 EW069 FD027 FD206 FD208 FD209

Claims (4)

[Claims] 1. A sheet having a plate surface diameter of 0.1 to 1.0 μm and a thickness of 0.02 to 0.08 μm, wherein zinc is contained in a molar ratio of 0.0010 to the total number of moles of Mg and Al. ~ 0.
Mg-Al-based hydrotalcite-type particle powder containing 0080, wherein the heat resistance time of the particle powder measured by the following measurement method is 4 hours or more.
-Al-based hydrotalcite-type particle powder. The resulting mixture 5 was prepared by mixing hydrotalcite-type particles and additives in a vinyl chloride resin at the following composition ratios.
0 g was kneaded using a hot roll to obtain a kneaded sheet. The kneading conditions are a kneading temperature of 155 ° C., a roll gap of 0.75 mm, and a kneading time of 3 minutes. Hydrotalcite-type particle powder: 3 parts by weight, vinyl chloride resin (degree of polymerization: 1300) (trade name: TK-1300, manufactured by Shin-Etsu Chemical): 100 parts by weight, diethylhexyl phthalate (DOP, manufactured by Daihachi Chemical): 50 Parts by weight, calcium stearate (primary reagent): 2 parts by weight, zinc stearate (primary reagent): 0.4 parts by weight, 1,3 diphenyl-1,3 propanedione (primary reagent): 0.2 parts by weight, Diethyl phosphate (primary reagent): 0.5 parts by weight. The obtained kneaded sheet is subjected to pressure treatment with a hot press,
A sheet piece (thickness 1.5 mm) was obtained. Pressing conditions are a pressing temperature of 160 ° C., a pressing pressure of 100 kg / cm ² , a pressing time of 1 minute, a pressing gap of 1.5 mm, and a processing amount of 35 g. The obtained sheet piece (20 mm × 20 mm) is placed in air 1
Place in an 80 ° C. oven and perform heat resistance test. The time during which the entire sheet piece turns black is defined as the heat resistance time. 2. The Mg-Al hydrotalcite-type particle powder according to claim 1, wherein the particle surface is coated with silicon hydroxide, silicon oxide or silicon hydroxide and silicon oxide. 2. The method according to claim 1, wherein
A Mg-Al-based hydrotalcite-type particle powder, wherein the heat resistance time measured by the measurement method described above is 4 hours or more. 3. Mg-Al according to claim 1 or claim 2.
Chlorine-containing resin stabilizer consisting of hydrotalcite-based particles. 4. An alkaline aqueous solution containing an anion,
A magnesium salt aqueous solution and an aluminum salt aqueous solution are mixed, and a zinc salt aqueous solution having a molar ratio of 0.02 to 0.25 with respect to the total mole number of Mg and Al is added to the mixed solution.
The method for producing Mg-Al-based hydrotalcite-type particles according to claim 1, wherein the H value is from 10 to 14 and aging is performed in a temperature range of from 60 to 105 ° C.