JP2016108177A - Hydrotalcite compound, resin composition containing the compound and molded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydrotalcite compound having a crystal structure and particle size property having a special energy state and useful for example as an acid acceptor and an absorbent of halogen or an absorbent and a stabilizer of chlorine ion because adsorptivity of anion is excellent.SOLUTION: There is provided a hydrotalcite compound represented by the chemical formula of (a), having stretching vibration frequency of a hydroxyl group calculated by a Fourier transformation (FT-IR) of 3430 cmor more and satisfying following particle size property of (b) to (d). (a) MgAl(OH)AmHO (b) 5≤Sw≤20 (m/g) (c) 0.5≤Dp≤2 (μm) (d) D≤10.09 (μm ), where Arepresents n valent anion, x is 0.1≤x≤0.5 and m is 0≤m<1, Sw: BET specific surface area measured by a nitrogen adsorption method (m/g), Dp: 50% average particle diameter measured by a laser diffraction scattering particle size distribution measure (μm) and D: maximum particle diameter measured by the laser diffraction scattering particle size distribution measure (μm).SELECTED DRAWING: None

Description

The present invention relates to a hydrotalcite compound having a crystal structure having a specific energy state and a specific particle size characteristic, a resin composition containing the hydrotalcite compound, and a molded article thereof.
Specifically, by having a crystal structure in a specific energy state and particle size characteristics such as particle size and uniformity, it has better anion adsorption than conventional hydrotalcite compounds, For example, hydrotalcites that are useful as stabilizers that absorb hydrogen chloride or chloride ions released from molecular chains such as polyvinyl chloride resin by ultraviolet rays or heating when blended with polyvinyl chloride resin. The present invention relates to a compound, a resin composition containing the compound, and a molded article.

Hydrotalcite compounds are usually represented by the composition formula M ²⁺ _1-x M ³⁺ _x (OH) ₂ A ^n- _{x / n} · mH ₂ O, and the crystal structure has a layered structure. It consists of a basic layer composed of a composite hydroxide of divalent (M ²⁺ ) and trivalent (M ³⁺ ) metals, and an intermediate layer having anions (A ⁿ⁻ ) and water between the basic layers. The base layer is positively charged by the coordination of trivalent metal ions instead of a part of the divalent metal ions, and the anion intercalates between the layers of the base layer, so that the total charge is reduced. Neutralized.
Hydrotalcite compounds can adsorb anions between the surface layer and the interlayer of the basic layer, and are blended in synthetic resins, synthetic rubbers, ceramics, paints, papers, toners, etc. depending on their ability, and are used as halogen scavengers and receivers. It is used in a wide range of applications as an excellent stabilizer having an effect as an acid agent and an absorbent.

  Chlorine-containing resins such as polyvinyl chloride resin are excellent in water resistance, acid resistance, alkali resistance, solvent resistance, flame resistance and electrical insulation, and are processed because they soften when heated and harden when cooled. It has excellent properties, and the softness of the molded product itself can be changed by adding a plasticizer. Furthermore, it is inexpensive and has a wide range of applications, including clothing, wallpaper, bags, cushion materials, heat insulating materials, soundproofing materials, and protection. Widely used in materials, ropes, wire coverings, screen doors, packaging materials, water pipes, building materials, agricultural films, erasers, etc.

However, when a chlorine-containing resin is exposed to heat, ultraviolet rays, etc., hydrogen chloride in the molecular chain is likely to be eliminated and a carbon double bond in the molecular chain is likely to be generated. It has the problem of attracting the elimination of hydrogen chloride from the molecular chain, creating a continuum of carbon double bonds in the molecular chain, increasing the coloration and brittleness, and reducing the commercial value. And measures against long-term use are necessary.
As countermeasures, various stabilizers have been added to improve and improve the stability of chlorine-containing resins, and various stabilizers such as lead-based, organotin-based, and metal soap-based have been proposed. It is used.
However, lead-based and organic tin-based stabilizers have recently been in the direction of being avoided because lead and tin themselves are harmful to the human body and the environment. Alternatives to zinc-barium stabilizers are in progress.
However, if a large amount of zinc-based stabilizer is added to the chlorine-containing compound for the purpose of improving heat resistance, the phenomenon of blackening of the resin called zinc scorch and the fact that the zinc-based stabilizer also acts as an external lubricant hinders kneading. There are problems such as.
Therefore, in addition to zinc-based stabilizers, research to improve heat resistance has progressed by adding and using a stabilizing aid such as the hydrotalcite compounds listed above, and currently focusing on soft vinyl chloride resin It is used.

On the other hand, molded products of chlorine-containing resins such as polyvinyl chloride resin may be exposed to sunlight outdoors or indoors depending on the application, and there is a problem of causing weather resistance deterioration such as coloring due to ultraviolet rays or reduced brittleness. In order to suppress the above, antioxidants such as organic acid metal salts, inorganic metal salts, phosphites, ultraviolet absorbers, light stabilizers and the like are blended.
However, the antioxidants, UV absorbers, and light stabilizers react with metal ions in the chlorine-containing resin and become colored, reducing the commercial value without producing the original color tone. There is a problem that performance cannot be exhibited and designed weather resistance cannot be obtained.

This phenomenon occurs even when a hydrotalcite compound containing a small amount of other metal elements based on magnesium or aluminum is used as a stabilizing aid in a chlorine-containing resin. Problems such as coloring are solved by adding a chemical aid (Patent Documents 1 and 2).
In addition, for example, a method for further preventing coloring without impairing the weather resistance by further adding a mercapto ester compound has been proposed (Patent Document 3).

In recent years, from the viewpoint of environmental protection and reduction of environmental load, chlorine-containing resins are also strongly required to have longer life, recycling, and reuse. As countermeasures, various stabilizers such as hydrotalcite-based compounds and ultraviolet absorbers are used as countermeasures. Proposals and investigations for increasing the amount of agent added are being made.
However, simply increasing the blending amount of various stabilizers such as hydrotalcite compounds and UV absorbers increases the opportunity for reaction between metal ions and UV absorbers, etc. Deterioration of weather resistance due to a decrease in capability is not preferable.
Therefore, it was proposed to increase the amount of β diketone, etc., which suppresses the reaction between various metal ions desorbed from the hydrotalcite compound and the UV absorber, depending on the hydrotalcite compound. Increasing the amount causes new problems such as burning of β-diketone itself at the time of kneading or molding, or blackening of the entire resin due to blackening, which prevents commercialization.
In addition, since the ester compound of mercapto is an organic substance, a phenomenon of floating from a resin called bleed occurs, so that it is unsuitable for addition in a large amount in applications such as electric wires that are used for a long time.
Furthermore, stabilizing aids such as β-diketones and ester compounds of mercapto have a problem that they are more expensive than stabilizing aids such as hydrotalcite compounds as well as lead-based and metal soap-based stabilizers.

The hydrotalcite compound can replace the metal ion in the basic layer made of the metal hydroxide depending on the reaction conditions. For example, magnesium which is a divalent metal ion of the hydrotalcite compound described above. It is also possible to replace some or all with other metals.
For example, hydrotalcite represented by the composition formula Zn _x Al ₂ (OH) _{4 + 2zx} CO ₃ · mH ₂ O (where 3.5 ≤ x ≤ 4.5, 0 ≤ m ≤ 4), in which all of magnesium is replaced with zinc It has been reported that the heat resistance of chlorine-containing resins is improved because the hydrotalcite compounds are superior in halogen absorption and acid-accepting ability to the conventional products including the hydrotalcite compounds described above. (Patent Document 4).

Further, a composition in which a part of magnesium is replaced with zinc (Mg _y Zn _z ) _1-x Al _x (OH) ₂ A ^n- _{x / n} · mH ₂ O (wherein 0.1 ≦ x ≦ 0.5, y + z = 1) , 0.5 ≦ y ≦ 1, 0 ≦ z ≦ 0.5, A is an n-valent anion, and 0 ≦ m ≦ 1) has been reported to improve the heat resistance of chlorine-containing resins. (Patent Documents 5 and 6).

  However, they focus only on improving the heat resistance when these hydrotalcite compounds are blended with chlorine-containing resins, and the use of zinc as a raw material for these hydrotalcite compounds is considered. Absent.

Zinc, which replaces part or all of magnesium in the hydrotalcite compounds mentioned above, is usually added during the reaction as chloride, sulfate or nitrate, and hydrotalcite is set under advanced reaction conditions. It is incorporated in the metal hydroxide layer which is the basic layer of the compound.
Zinc chloride, sulfate, and nitrate are obtained by reacting zinc oxide and metallic zinc with hydrochloric acid, sulfuric acid, and nitric acid, but most zinc oxide and metallic zinc are zinc blende (ZnS) and rhombozincite. It is obtained by refining zinc ore such as (ZnCO ₃ ) and then roasting to obtain zinc ore (ZnO) or by refining the zinc ore by a dry method or a wet method (electrolytic refining).
However, since zinc sulfate is in the form of zinc sulfate at the time of electrolytic refining, it is not necessary to refine even metallic zinc if the purpose is to obtain it.
However, since sphalerite contains cadmium and chalcopyrite contains lead, the refining process for removing these harmful substances, protecting the environment, protecting workers, etc. is advanced, and zinc oxide and metal Also, hydrochloric acid, sulfuric acid, and nitric acid that react with zinc are required, resulting in high manufacturing costs.
Furthermore, in Japan, zinc itself is regulated by the Water Pollution Law, and the concentration (drainage standard) in the discharged water is regulated to 2 ml / L or less (promulgated on November 10, 2006). However, this has become a severe burden on costs and handling.
Therefore, it has been demanded to further improve the anion absorption capacity without using materials such as zinc, which are burdensome on the environment, cost, and handling.

Japanese Unexamined Patent Publication No. 57-80444 Japanese Unexamined Patent Publication No. 06-192520 JP 2013-10834 A Japanese Patent Publication No. 11-255973 W099 / 01409 Publication W099 / 05219 Publication

The present invention provides various resins, particularly chlorine-containing resins, for the purpose of reducing recent environmental burdens, and has excellent water resistance, acid resistance, alkali resistance, solvent resistance, flame resistance, and electrical insulation properties. To provide hydrotalcite compounds that improve heat resistance without sacrificing economics, extend life, recycle, and reuse, while maintaining processability and properties according to the use of molded products Objective.
Specifically, paying attention to the energy state of hydrotalcite compounds, and having a specific crystal structure, the adsorbability of anions is superior to conventional hydrotalcite compounds, and the size and uniformity of the particles It aims at providing the hydrotalcite composition which does not impair the intensity | strength characteristic, when it mix | blends with various resin and it is set as a resin composition by having particle size characteristics, such as.
Furthermore, by utilizing the adsorbability of anions, the hydrogel of the present invention can be used as a stabilizer that absorbs hydrogen chloride or chlorine ions that are desorbed from molecular chains such as polyvinyl chloride resin by ultraviolet rays or heating. It aims at providing resin compositions, such as a polyvinyl chloride resin composition which mix | blended the talcite type compound, and a molded object.

  In view of such circumstances, the present inventor has eagerly studied to achieve the above object, and as a result, a hydrotalcite compound having a crystal structure in a specific energy state and a specific particle size characteristic has an adsorption capacity for anions and in a resin. It has been found that, when blended in a resin, it is excellent in absorption of anions such as halogen in the resin. Specifically, the hydrotalcite compound is, for example, halogenated. It was found that when blended in a resin composition to be contained, the resin composition was imparted with excellent stability due to excellent halogen capture and adsorption properties, and the present invention was completed.

The present invention includes the following inventions.
(1) The hydroxyl group stretching vibration frequency expressed by the chemical formula (a) below and obtained by Fourier transform (FT-IR) is 3430 cm ⁻¹ or more, and satisfies the following particle size characteristics (b) to (d). Hydrotalcite compounds characterized by
(A) Mg _1-x Al _x (OH) ₂ A ^n-1 _{x / n} · mH ₂ O
(B) 5 ≦ Sw ≦ 20 (m ² / g)
(C) 0.5 ≦ Dp ₅₀ ≦ 2 (μm)
(D) D _Max ≦ 10.09 (μm)
However, in the formula of (a), A ^n- represents an n-valent anion, x is 0.1 ≦ x ≦ 0.5, m is 0 ≦ m <1.
Sw: BET specific surface area (m ² / g) measured by nitrogen adsorption method
Dp ₅₀ : 50% average particle diameter (μm) of hydrotalcite compound compound measured with a laser diffraction / scattering particle size distribution analyzer,
D _Max : The maximum particle size (μm) of the hydrotalcite compound compound measured with a laser diffraction / scattering particle size distribution analyzer.
(2) The above-described surface treatment with at least one surface treatment agent selected from fatty acids, alicyclic carboxylic acids, aromatic carboxylic acids, resin acids, metal salts thereof, and esters thereof Hydrotalcite compounds.
(3) A resin composition comprising the hydrotalcite compound of (1) or (2) and a resin.
(4) The resin composition as described in (3) above, wherein the resin is a vinyl chloride resin.
(5) A molded product comprising the resin composition of (3) above.
(6) A molded article comprising the resin composition of (4) above.

According to the present invention, a hydrotalcite compound having an anionic adsorptivity superior to a conventional hydrotalcite compound by having a crystal structure of a specific energy state and a specific particle size characteristic, and containing the same The resin composition which becomes, and its molded object can be provided.
The hydrotalcite compound of the present invention utilizes the superior adsorption property of its anion. For example, the hydrotalcite compound of hydrogen chloride or chloride ion desorbed from a molecular chain such as a polyvinyl chloride resin by ultraviolet rays or heating, for example. Useful as a trapping / adsorbing agent or stabilizer.

The hydrotalcite compound of the present invention is represented by the following chemical formula (a), and the hydroxyl group stretching vibration frequency determined by Fourier transform (FT-IR) is 3430 cm ⁻¹ or more, and the following (b) to ( It is characterized by satisfying the particle size characteristic of d).
(A) Mg _1-x Al _x (OH) ₂ A ^n-1 _{x / n} · mH ₂ O
(B) 5 ≦ Sw ≦ 20 (m ² / g)
(C) 0.5 ≦ Dp ₅₀ ≦ 2 (μm)
(D) D _Max ≦ 10.09 (μm)
In the formula, A ⁿ⁻ represents an n-valent anion, x is 0.1 ≦ x ≦ 0.5, and m is 0 ≦ m <1.
Sw: BET specific surface area (m ² / g) measured by nitrogen adsorption method
Dp ₅₀ : 50% average particle diameter (μm) of hydrotalcite compound compound measured with a laser diffraction / scattering particle size distribution analyzer,
D _Max : The maximum particle size (μm) of the hydrotalcite compound compound measured with a laser diffraction / scattering particle size distribution analyzer.

The hydrotalcite compound of the present invention is represented by the chemical formula (a). Examples of the n-valent anion include divalent CO ₃ ²⁻ , SO ₄ ^2−, and monovalent OH ⁻ , F ⁻ , Cl ⁻ , Br ⁻ , NO ₃ ⁻ and I ⁻ . Divalent CO ₃ ^2- is easy to obtain, is economically effective, is advantageous in terms of environmental burden, and is stable and good as a hydrotalcite compound in the examination so far. The hydrotalcite compound of the present invention has a hydroxyl group (OH) stretching vibration frequency (hereinafter simply referred to as a hydroxyl group stretching vibration frequency) determined by Fourier transform (FT-IR) within the above range. Increases the amount of anion adsorbed and improves the ability to capture, adsorb and absorb halogens when incorporated in a resin, and is effective as an acid acceptor and stabilizer.
Although this mechanism is not always clear, halogens are bonded or adsorbed to the surface of the hydrotalcite particles or between the hydroxyl groups by hydrogen bonds, etc., and the energy state of the hydroxyl groups affects the ease of bonding and adsorption, the adsorption rate, and the adsorption amount. It has a large influence, and it is assumed that the energy state is improved by setting the energy state in the above-described range.
The stretching vibration frequency of the hydroxyl group is considered to be measured not only from the hydroxyl group of the hydrotalcite basic layer (metal hydroxide layer) but also from the stretching vibration energy of the hydroxyl group water contained between the layers. In addition, the stretching vibration frequency of the hydroxyl group in the interlayer water seems to be strongly influenced by the energy state of the hydroxyl group in the hydrotalcite base layer, but the effect is unknown. And, it is conceivable that the stretching vibration frequency of the hydroxyl group of interlayer water has some influence on the capture, adsorption and absorption of halogen, but the mechanism is also unknown.
For the above reason, if a hydrotalcite compound having a hydroxyl group stretching vibration frequency larger than usual is selected and blended with the resin, for example, chlorine or chloride ions desorbed from the molecular chain in the polyvinyl chloride resin, Bonding and adsorption reactions of hydrogen chloride with hydroxyl groups on the surface and between layers of hydrotalcite compound particles are performed well, improving the amount of trapped, adsorbed, and absorbed chlorine and chloride ions in the resin. It is considered that the heat stability is improved.

The stretching vibration frequency of the hydroxyl group needs to be 3430 cm ^-1 or more, and hydrotalcite compounds smaller than this value have a small amount of anion adsorption. For example, when compounded in polyvinyl chloride resin, chlorine or chlorine ions in the resin The amount of trapped, adsorbed and absorbed is insufficient, and means for improving this is required. This applies to the hydrotalcite mentioned in the prior art.
A hydrotalcite compound having a hydroxyl group stretching vibration frequency exceeding 4000 cm ⁻¹ has not been obtained in the study of the present invention.
The stretching vibration frequency of the hydroxyl group in the present invention was measured with FT-IR660Plus manufactured by JASCO Corporation.

The BET specific surface area Sw of the hydrotalcite compound measured by the nitrogen adsorption method of (b) above is 5 to ²⁰ m ² / g. By being within this range, the hydrotalcite compound is produced or used. When handling, for example, when blended with a vinyl chloride resin as a stabilizer or acid acceptor, for example, it is well dispersed in the resin and a halogen adsorption reaction easily occurs.

When the BET specific surface area Sw is less than 5 m ² / g, the production is difficult. On the other hand, when the BET specific surface area Sw is more than 20 m ² / g, the cost and handling during the production of the hydrotalcite compound deteriorate, which is not preferable. When blended with a chlorine-containing resin, voids and depressions called sinks and fine foaming are liable to occur, which not only impairs the appearance of the molded product, but also causes a decrease in strength properties and insulation properties.
The reason why sink marks and fine foaming occur when blended with a chlorine-containing resin is unknown, but the surface area of the hydrotalcite compound particles increases and the area exposed to the resin increases. It is speculated that there is.
The nitrogen adsorption type BET specific surface area Sw in the present invention was measured with NOVA2000 manufactured by Yuasa Ionics.

The 50% average particle diameter Dp ₅₀ of the hydrotalcite compound obtained by the laser diffraction / scattering particle size distribution analyzer of (c) is 0.5 ≦ Dp ₅₀ ≦ 2 (μm), preferably 0.5 ≦ Dp ₅₀ ≦ 1.5 ( Similarly, the maximum particle diameter D _Max measured by the laser diffraction / scattering particle size distribution analyzer of (d) above is D _Max ≦ 10.09 (μm), preferably D _Max ≦ 8.482 (μm), Those having little or little secondary aggregation are preferred.

Particles having a 50% average particle diameter Dp ₅₀ of less than 0.5 μm are difficult to produce, and particles having the 50% average particle diameter Dp ₅₀ of less than 0.5 μm can be obtained by observation with an electron microscope or the like. Since the surface energy of the particles becomes too large and tends to agglomerate and stabilize, particles showing such values in particle size measurement have not been obtained at this time.
On the other hand, when the average particle diameter Dp ₅₀ exceeds 2 μm, for example, when blended with a chlorine-containing resin, the heat resistance is slightly inferior, and when these resins are used for coatings for electric wires, the insulation tends to decrease. This is not preferable. The reason for this is unclear, but it is presumed that when blended with a chlorine-containing resin, one particle is large, so the density of the number in the resin decreases and the anion adsorption capacity decreases.

When the maximum particle size D _{Max in} (d) exceeds 10.09 μm, the heat resistance is slightly inferior when blended with a chlorine-containing resin, and coloring called initial coloring tends to deteriorate, which is not preferable.
The reason for this is also unclear, but when blended with a chlorine-containing resin, the presence of large particles in the resin is presumed to have a bad influence.

The hydrotalcite compound of the present invention can be produced by considering the following reaction conditions.
As described above, the stretching vibration frequency, average particle diameter Dp ₅₀ , maximum particle diameter D _Max , and BET specific surface area Sw of the hydroxyl group are determined by using a solution in which raw materials such as Mg, Al, CO ₃ and OH have been dissolved. The pH of the solution reaction when the hydrotalcite compound is produced by mixing, and the temperature, time, and stirring during the hydrothermal reaction of the resulting hydrotalcite compound reaction solution may be affected. It turns out.
However, the above conditions affect each physical property of the hydrotalcite compound of the present invention, and the magnitude and correlation of each effect are not necessarily clear.
As a tendency, first, when the pH during the solution reaction is increased, the stretching vibration frequency of the hydroxyl group increases. Next, when the temperature during the hydrothermal reaction is increased, the average particle diameter Dp ₅₀ and the maximum particle diameter D _Max increase, and the BET specific surface area Sw tends to decrease. The maximum particle diameter D _Max increases when the temperature is lowered too much, but this is considered to be caused by aggregation of fine particles.
As the time during the hydrothermal reaction is increased, the average particle diameter Dp ₅₀ and the maximum particle diameter D _Max increase, and the BET specific surface area Sw tends to decrease. However, the maximum particle diameter D _Max increases as the time is short, but this is considered to be caused by aggregation of fine particles.
Regarding the stirring during the hydrothermal reaction, when the number of stirring is increased, the average particle diameter Dp ₅₀ tends to be small and the maximum particle diameter D _Max tends to be small.
Since the BET specific surface area Sw is large regardless of whether the number of stirring is large or small, it is necessary to appropriately select the number of stirring depending on the reaction apparatus and reaction conditions.

The hydrotalcite compound of the present invention is used for the purpose of improving various physical properties such as durability and strength when blended and molded into a resin to form a resin molded body, and the stability and dispersibility of the particles. In order to impart affinity and water repellency, it is preferable to perform surface treatment with a surface treating agent such as fatty acid, alicyclic carboxylic acid, aromatic carboxylic acid, resin acid, metal salt thereof, or ester thereof.
The above surface treatment agents are used alone or in combination of two or more as required. From the viewpoints of various physical properties of the resin composition, application, environmental impact, handling properties, and cost, fatty acids and metal salts thereof are used. preferable.

  Examples of fatty acids, alicyclic carboxylic acids, aromatic carboxylic acids, and resin acids used in the present invention include acetic acid, butyric acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, Saturated fatty acids such as arachidic acid, behenic acid, lignoceric acid; unsaturated fatty acids such as sorbic acid, elaidic acid, palmitoleic acid, oleic acid, linoleic acid, linolenic acid, cetoleic acid, erucic acid, ricinoleic acid; cyclopentane ring and cyclohexane Ring-containing alicyclic carboxylic acid such as naphthenic acid; benzene carboxylic acid represented by benzoic acid, phthalic acid, etc .; aromatic carboxylic acid such as naphthoic acid carboxylic acid such as naphthoic acid and naphthalic acid; abietic acid, pimaric acid Resin acids such as parastrinic acid and neoabietic acid. Or reactive with sites such compound, particle stability, dispersibility, ease to obtain, mixed acid stearic acid and palmitic acid are preferable in terms of cost.

  Examples of each metal salt of fatty acid, alicyclic carboxylic acid, aromatic carboxylic acid, and resin acid include, for example, potassium laurate, potassium myristate, potassium palmitate, sodium palmitate, barium stearate, calcium stearate, zinc stearate , Potassium stearate, cobalt stearate (II), tin stearate (IV), sodium stearate, potassium stearate, lead stearate (II) saturated fatty acid salts; zinc oleate, potassium oleate, cobalt oleate (II), unsaturated fatty acid salts such as sodium oleate; alicyclic carboxylates such as lead naphthenate and lead cyclohexylbutyrate; aromatic carboxylates such as sodium benzoate and sodium salicylate.

  Further, during or before the surface treatment of the hydrotalcite compound of the present invention, the above-described fatty acid, alicyclic carboxylic acid, aromatic carboxylic acid, resin acid, lithium, sodium, potassium, rubidium, beryllium, magnesium, Metal salts of these acids may be prepared by mixing and reacting compounds having calcium, strontium, barium, zinc, aluminum, lead, cobalt, and tin.

  Among the above fatty acid, alicyclic carboxylic acid, aromatic carboxylic acid and resin acid metal salts, in terms of reactivity with hydrotalcite compounds, particle stability, dispersibility, availability, and cost It is preferable to use a mixed soap mainly composed of stearic acid or palmitic acid.

  Examples of esters of fatty acids, alicyclic carboxylic acids, aromatic carboxylic acids, and resin acids include, for example, ethyl caproate, vinyl caproate, diisopropyl adipate, ethyl caprylate, allyl caprate, ethyl caprate, vinyl caprate , Diethyl sebacate, diisopropyl sebacate, cetyl isooctanoate, octyldodecyl dimethyloctanoate, methyl laurate, butyl laurate, lauryl laurate, methyl myristate, isopropyl myristate, cetyl myristate, myristyl myristate, isocetyl myristate Octyldodecyl myristate, isotridecyl myristate, methyl palmitate, isopropyl palmitate, octyl palmitate, cetyl palmitate, isostearyl palmitate, Saturated fatty acid esters such as methyl phosphate, butyl stearate, octyl stearate, stearyl stearate, cholesteryl stearate, isocetyl isostearate, methyl behenate, behenyl behenate; methyl oleate, ethyl linoleate, isopropyl linoleate, olive Unsaturated fatty acid esters such as ethyl oleate and methyl erucate; other long-chain fatty acid higher alcohol esters, neopentyl polyol (including long and medium chain) fatty acid esters and partial ester compounds, dipentaerythritol long-chain fatty acid esters , Complex medium chain fatty acid ester, 12-stearoyl stearic acid isocetyl / isostearyl / stearyl, beef tallow fatty acid octyl ester, polyhydric alcohol fatty acid ester / alkyl glyceryl ester Examples thereof include heat-resistant special fatty acid esters such as ether fatty acid esters and aromatic esters represented by benzoic acid esters. Among them, the use of polyhydric alcohol fatty acid ester polyhydric alcohol stearic acid, polyhydric alcohol palmitic acid, polyhydric alcohol stearyl stearate in terms of reactivity with hydrotalcite compounds, particle stability, dispersibility, and cost Is preferred.

The treatment amount of the surface treatment agent is appropriately selected depending on the type and use of the resin in which the hydrotalcite compound obtained in the present invention is used. For example, the acid acceptor of the polyolefin resin catalyst or the polyvinyl chloride resin When used as a stabilizer, the amount is usually 0.01 to 15% by weight, preferably 0.05 to 8% by weight, based on 100% by weight of the particles.
When the treatment amount of the surface treatment agent is less than 0.01% by weight, a sufficient effect of the surface treatment agent is not recognized, and it is not preferable because it causes deterioration in handling and cost increase during production. On the other hand, when the treatment amount exceeds 15% by weight, for example, when a molded body is prepared by blending with a resin, the strength of the resin is remarkably lowered, and in some cases, even the shape of the molded body cannot be maintained, which is not preferable.

The second of the present invention relates to a resin composition comprising the hydrotalcite compound of the present invention and a resin.
The hydrotalcite compound of the present invention is usually blended in an amount of 0.001 to 10 parts by weight, preferably 0.01 to 5 parts by weight per 100 parts by weight of the resin.

The resin in which the hydrotalcite compound of the present invention is used may be any resin as long as it is usually used as a molded product, but in general, a thermoplastic resin is preferably used.
For example, polyolefin resins such as polymers or copolymers of C2 to C8 olefins (α-olefins) such as polyethylene, polypropylene, ethylene-propylene polymer, polybutene, poly (4-methylpentene-1), These olefin and diene copolymers, ethylene-acrylate copolymer, polystyrene, ABS resin, AAS resin, AS resin, MBS resin, ethylene-vinyl chloride copolymer resin, ethylene-vinyl acetate copolymer resin, ethylene -Vinyl chloride-vinyl acetate copolymer resin, polyvinylidene chloride, polyvinyl chloride, chlorinated polyethylene, chlorinated polypropylene, vinyl chloride-propylene copolymer, polyvinyl acetate, phenoxy resin, polyacetal, polyamide, polyimide, polycarbonate, Polysulfone, polyphenylene Kisaido, polyphenylene sulfide, polyethylene terephthalate, polybutylene terephthalate, include resin such methacrylonitrile system, they are used singly or in combination of two or more, if necessary.

Among these thermoplastic resins, examples of excellent thermal deterioration prevention effect and mechanical strength retention property by the hydrotalcite compound of the present invention are polyolefins or copolymers thereof, and halogen-containing resins, specifically Are polypropylene homopolymers, polypropylene resins such as ethylene-propylene copolymers, high density polyethylene, low density polyethylene, linear low density polyethylene, ultra low density polyethylene, EEA (ethylene ethyl acrylate resin), EVA (ethylene vinyl). Acetate resin), EMA (ethylene acrylic methyl copolymer resin), EAA (ethylene acrylic acid copolymer resin), polyethylene resins such as ultra-high molecular weight polyethylene, and C2 such as polybutene and poly (4-methylpentene-1). ~ C8 polyolefin (α- Polymer or copolymer of styrene) and the like.
Among these, polyethylene, polypropylene, polybutene, poly (4-methylpentene-1) or a copolymer thereof is particularly preferable. Furthermore, biodegradable plastics such as polylactic acid resin, polybutylene succinate, polyamide 11 and polyhydroxybutyric acid and biomass plastics can also be used.

These polyolefin resins contain halogens derived from Ziegler-based polymerization catalysts in the resins. However, since the hydrotalcite compounds of the present invention are extremely excellent in absorption and acid reception of these halogens, The effect of suppressing the thermal degradation caused by is excellent.
In addition, the hydrotalcite compound of the present invention is particularly excellent in the effect of suppressing thermal deterioration for the same reason with respect to a polyvinyl chloride resin or a copolymer thereof.

  In addition, thermosetting resins such as epoxy resin, phenol resin, melamine resin, unsaturated polyester resin, alkyd resin and urea resin, and EPDM, butyl rubber, isoprene rubber, SBR, NBR, chlorosulfonated polyethylene, NIR, urethane rubber It can also be applied to synthetic rubbers such as butadiene rubber, acrylic rubber, silicone rubber and fluorine rubber.

There are no particular restrictions on the method of compounding the hydrotalcite compound of the present invention into a resin or rubber, and for example, the same method as a known method of compounding various stabilizers and fillers used in the above-described resins and rubbers into these. By means, it may be blended with other compounding agents or separately in resin or rubber so as to be as uniform as possible.
Specifically, a method of blending using a known mixing device such as a ribbon blender, a high-speed mixer, a kneader, a pelletizer, an extruder, or a suspension of a thermal deterioration inhibitor containing a hydrotalcite compound as an active ingredient. Can be added to the slurry after polymerization while stirring and mixing and drying.

  In the resin composition containing the hydrotalcite compound of the present invention, other additives can be blended in addition to the above components as long as the efficacy of the present invention is not impaired. Examples of such additives include antioxidants, antistatic agents, pigments, foaming agents, plasticizers, fillers, reinforcing agents, flame retardants, crosslinking agents, light stabilizers, ultraviolet absorbers, lubricants, and the like other than the above. Inorganic or organic stabilizers may be mentioned.

EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example and a comparative example, this invention is not limited at all by these examples.
In Examples and Comparative Examples of the present invention, the stretching vibration frequency of the hydroxyl group of the hydrotalcite compound was measured by FT-IR660Plus manufactured by JASCO Corporation.
The average particle size Dp ₅₀ and the maximum particle size D _Max of the hydrotalcite compound were measured with a Microtrac MT3300EX II laser diffraction / scattering particle size distribution meter manufactured by Microtrac Bell.
The BET specific surface area Sw of the hydrotalcite compound was measured with NOVA2000 manufactured by Yuasa Ionics Co., Ltd.
The SO ₂ adsorption amount of hydrotalcite compounds is measured by placing a scale with hydrotalcite in a sealed container, filling nitrogen in the container, and then filling sulfur dioxide at a pressure of 500 torr for 1 hour. After the lapse of time, the system was sealed with nitrogen to deaerate sulfur dioxide, and the increased weight of the hydrotalcite compound was defined as the sulfur dioxide adsorption amount, that is, the anion adsorption amount.
The compositional analysis of hydrotalcite compounds was measured and calculated by ICP-MS method, CO ₃ by CHN measurement method, and OH and H ₂ O content by calorimetric analysis method.

Example 1
A 3.5 mol / L magnesium chloride solution and a 1.0 mol / L aluminum sulfate solution were mixed so that the molar ratio of magnesium to aluminum was 2.1: 1 and adjusted to 20 ° C.
Next, an 18.08 mol / L sodium hydroxide solution and a 0.51 mol / L sodium carbonate solution were mixed so that the molar ratio of hydroxide to carbonate group was 6.4: 1 and adjusted to 20 ° C.
The reaction of the hydrotalcite compound is a continuous method in which both solutions are mixed and reacted while maintaining the pH within the range of 13.0 ± 0.1, and the reaction solution overflows from the top of the reaction tank. A liquid was created.
Further, the obtained reaction solution was put into an autoclave, and after stirring at 120 rpm, the temperature was raised to 150 ° C. in 70 minutes and maintained for 6 hours, and then allowed to cool to room temperature to suspend the hydrotalcite compound. A liquid was obtained.
The obtained hydrotalcite compound suspension was dehydrated with a press filter and washed with tap water, and the washing was terminated when the washing wastewater became 20 μS / cm higher than the electric conductivity of the tap water.
Furthermore, the liquid temperature was adjusted to 80 ° C., and the product was equivalent to 2.2% by weight based on the hydrotalcite compound in the hydrotalcite compound suspension, 65% of commercially available sodium stearate-35% sodium palmitate A surface treatment agent composed of a mixed soap (industrial use) was dissolved in water at 80 ° C. and then added, followed by stirring for 60 minutes for surface treatment of the hydrotalcite compound.
The obtained suspension of surface-treated hydrotalcite compound was dehydrated again with a press filter to form a cake, then dried in a gear oven at 105 ° C for 12 hours, and then crushed with a Koroflex pulverizer. A dry powder of a hydrotalcite compound was obtained.
The resulting surface-treated hydrotalcite compound has a hydroxyl group stretching vibration frequency of 3432 cm ^-1 , a BET specific surface area Sw of 12.6 m ² / g, and a chemical formula of Mg _0.673 Al _0.327 (OH) ₂ (CO ₃ ) _0.15 · 0.53H _{With 2} O, the particles had an average particle diameter Dp ₅₀ of 1.52 μm, a maximum particle diameter D _Max of 10.09 μm, and an SO ₂ adsorption amount of 202 mg / g.
Table 1 shows the reaction conditions, various physical properties and chemical formula of the obtained surface-treated hydrotalcite compound.

Examples 2-16, Comparative Examples 1-4
Except for changing the pH during the solution reaction, the number of stirring during the hydrothermal reaction, the temperature, and the time as described in Table 1, the same operation as in Example 1 was carried out. A surface-treated hydrotalcite compound having a specific surface area, average particle size, maximum particle size, and SO ₂ adsorption amount was obtained.

Examples 17-32, Comparative Examples 5-8
After mixing the surface-treated hydrotalcite compounds obtained in Examples 1 to 16 and Comparative Examples 1 to 4 with the following composition, sheets were prepared with a roll kneader set at 161 ° C.
Composition: Polyvinyl chloride resin (degree of polymerization 1300) 100 parts by weight
DOP 50 parts by weight Zinc stearate 0.5 parts by weight Dibenzoylmethane (β-diketone) 0.1 parts by weight Hydrotalcite compound 1.5 parts by weight Further, using a pressure press with a heater in which the obtained sheet is set at 160 ° C., the thickness A 1 mm sheet was prepared, and the physical properties were measured and evaluated by the following methods. The results are shown in Tables 2 and 3.

<Heat resistance degradation>
Cut the prepared sheet into 20mm x 10mm, place it in a gear oven (Gabeh GPHH-100 manufactured by Tabai Espec Corp.) with a damper opening of 50% at 190 ° C and take it out every 15 minutes until the specimen turns black Seeking time.

<Initial colorability>
The prepared sheet was cut into 20 mm × 20 mm, and the sheet was taken out after being heated at 190 ° C. for 30 minutes while applying pressure using a pressure press with a heater, and the hue of the sheet was measured.
The apparatus was evaluated by the YI value of transmitted light using a colorimetric color difference meter ZE 2000 manufactured by Nippon Denshoku Industries Co., Ltd.

<Sink and foam resistance>
Cut out the prepared sheet to 20mm x 20mm, apply pressure using a pressure press with a heater, take it out after heating the sheet at 190 ° C for 5, 15, and 30 minutes. Indentations and voids in the sheet were observed and evaluated according to the following five levels.
5: No sink marks or bubbles in the sheet 4: Fine bubbles (less than 0.1 mm) are observed at the edge of the sheet 3: 2-5 sink marks of about 1 to 2 mm and fine bubbles are observed in the sheet 2: Sheet 6 or more sink marks of about 1 to 2 mm are observed in the sheet. 1: There are remarkable sink marks and bubbles on the entire sheet surface.

<Volume specific resistance>
The measurement was performed in accordance with JIS K6723 according to the following procedure. That is, a sheet of 120 mm or more in length and breadth is punched from the prepared sheet, the thickness of the test piece is measured at five locations, the average value is taken as the thickness, and the test apparatus and the punched sheet are placed in a thermostat set at 30 ° C. for 30 minutes or more. The volume resistivity was measured at an applied voltage of 500 V and a charging time of 1 minute.
The apparatus used was Agilent Technologies' 4339B High Resistance Mater.

ADVANTAGE OF THE INVENTION According to this invention, the hydrotalcite compound which was excellent in the adsorptivity of an anion than the conventional hydrotalcite compound can be provided by having the crystal structure of a specific energy state, and a specific particle size characteristic.
The hydrotalcite compound of the present invention utilizes the superior adsorption property of its anion. For example, the hydrotalcite compound of hydrogen chloride or chloride ion desorbed from a molecular chain such as a polyvinyl chloride resin by ultraviolet rays or heating, for example. Useful as a trapping / adsorbing agent or stabilizer.

Claims (6)

It is represented by the chemical formula of the following (a), and the stretching vibration frequency of the hydroxyl group determined by Fourier transform (FT-IR) is 3430 cm ⁻¹ or more, and satisfies the particle size characteristics of the following (b) to (d). Characteristic hydrotalcite compound.
(A) Mg _1-x Al _x (OH) ₂ A ^n-1 _{x / n} · mH ₂ O
(B) 5 ≦ Sw ≦ 20 (m ² / g)
(C) 0.5 ≦ Dp ₅₀ ≦ 2 (μm)
(D) D _Max ≦ 10.09 (μm)
However, in the formula of (a), A ^n- represents an n-valent anion, x is 0.1 ≦ x ≦ 0.5, m is 0 ≦ m <1.
Sw: BET specific surface area (m ² / g) measured by nitrogen adsorption method
Dp ₅₀ : 50% average particle diameter (μm) of hydrotalcite compound compound measured with a laser diffraction / scattering particle size distribution analyzer,
D _Max : The maximum particle size (μm) of the hydrotalcite compound compound measured with a laser diffraction / scattering particle size distribution analyzer.   2. The surface treatment is performed with at least one surface treatment agent selected from fatty acids, alicyclic carboxylic acids, aromatic carboxylic acids, resin acids, metal salts thereof, and esters thereof. Hydrotalcite compounds.   A resin composition comprising the hydrotalcite compound according to claim 1 or 2 and a resin.   The resin composition according to claim 3, wherein the resin is a vinyl chloride resin.   A molded article comprising the resin composition according to claim 3.   A molded body comprising the resin composition according to claim 4.