WO2009153936A1 - Magnesium hydrate composition and manufacturing method thereof, and resin composition and molded article thereof - Google Patents

Abstract

Provided is a magnesium hydrate composition comprising magnesium hydrate particles containing iron and/or manganese and sulfur. The content (M) of the iron and/or manganese as measured using an atomic absorption spectrophotometer is in the range of 10-1,000 ppm with respect to the magnesium hydrate particles, the content (S) of the sulfur as measured using an infrared absorption method is in the range of 10-1,800 ppm with respect to the magnesium hydrate particles, and the ratio (S/M) of the content (S) of the sulfur to the content (M) of the iron and/or manganese is in the range of 1.0-1.8. The magnesium hydrate composition has excellent flame retardancy and sustainability thereof when mixed with a resin, and excellent thermal deterioration resistance and a good hue can be imparted.

Description

Magnesium hydroxide composition, process for producing the same, resin composition and molded article thereof

The present invention provides a magnesium hydroxide composition that imparts higher flame retardancy and better hue than conventional magnesium hydroxide to a resin, a method for producing the same, and heat deterioration resistance obtained by blending the resin with the resin, The present invention relates to a resin composition excellent in flame retardancy and a molded product comprising the same. More specifically, the magnesium hydroxide particles having excellent dispersibility when blended with the resin improve the flame retardancy by containing a specific metal element, and further the hue deterioration caused by the inclusion of the metal element. The present invention relates to a magnesium hydroxide composition characterized by being hardly present, a production method thereof, a resin composition excellent in heat deterioration resistance and flame retardancy obtained by blending it with a resin, and a molded article comprising the same.

Synthetic resins are used in various fields because the resin itself is lighter and stronger than metal, easy to mold, and inexpensive. However, since resin is much easier to burn than metal, there is a demand for flame retardancy for resin molded products, and the demand is high and severe. In order to meet the demand for flame retardancy, flame retardants using halogen compounds and antimony trioxide in combination have been proposed and widely used.

However, this halogen compound is exposed to high temperatures during molding processing, and partly decomposes at that temperature to generate halogen gas, which corrodes the processing machine and molding machine. Heat resistance and weather resistance of resins and rubbers There are problems in manufacturing and physical properties such as adversely affecting the above. In addition, since halogen gas is toxic to the human body, it not only deteriorates the working environment during production, but also when a fire occurs during use by compounding with resin or rubber, and molded products When it is disposed of or incinerated, there is a problem that a large amount of smoke containing toxic gas is generated. In particular, the generation of toxic gases at the time of a fire is a serious problem, and it is used for the purpose of increasing the evacuation time of people who are indoors, for example, by delaying the spread of fire by making flame-retardant resin molded products in the event of a fire Nevertheless, the poisonous gas can have a negative effect on health and can even lead to the loss of human life. Such a case is the end of the end as the purpose of the original use of the halogen compound and should be avoided absolutely.
Moreover, phosphorus flame retardants are mentioned as flame retardants other than halogen flame retardants. However, since many phosphorus-based flame retardants are liquid, they degrade mechanical strength such as impact resistance of blended resin molded products, and are easily hydrolyzed. Therefore, long-term water resistance and weather resistance of molded products Has a number of problems that need to be solved, such as the inferiority and the risk of environmental hormone contamination due to the seepage of phosphorus compounds. For example, it meets UL-94 standards required for electric wires, cables, automotive harnesses, etc. On the other hand, it is difficult to eliminate the influence on water resistance, weather resistance, and environment over a long period of time with the current technology.

For this reason, demand for non-halogen flame retardants that do not have the above problems has increased, and metal hydroxides such as aluminum hydroxide and magnesium hydroxide have attracted attention. However, since aluminum hydroxide is decomposed and dehydrated from about 190 ° C, if it is blended with a resin having a molding process temperature of 190 ° C or higher, the aluminum hydroxide decomposes, dehydrates and foams during processing, and manufacturing handling This not only makes it difficult, but also has a problem that the resin to be used is limited because the commercial value is remarkably impaired, for example, the physical properties such as the strength and weather resistance of the resin and rubber are lowered and the appearance of the product is also impaired.

On the other hand, since magnesium hydroxide has a dehydration and decomposition start temperature of 340 ° C., it has an advantage that it can be blended into most resins. Magnesium hydroxide is a natural or heavy product that is finely pulverized from natural mineral brucite and classified as necessary to adjust the particle size. There is a compound obtained by purifying bitter juice containing magnesium chloride as a by-product as a main component and then reacting with alkali.

These magnesium hydroxide particles are desired to be fine, uniform and excellent in dispersibility in order not to impair the appearance, strength, durability and the like of the resin molded product obtained by blending them. When single or strongly aggregated large particles are present in a resin molded product, for example, when used in molded products such as the above-mentioned electric wires, cables, and automobile harnesses, fine, uniform, and highly dispersible particles are used. As compared to the molded product, the surface of the molded product has more irregularities and convex portions, and the appearance is impaired. In addition, it is well known and generally used to improve impact resistance and tensile strength when inorganic particles such as magnesium hydroxide are blended with resin or rubber. It is also known that when the particle size is large, the strength properties are lowered. Although the detailed mechanism is not clear at present, the strength of the resin molded article does not satisfy the desired physical properties when large particles are present in the resin regardless of single or aggregated particles. Furthermore, it becomes easy to be exposed on the surface of the molded product, and it takes in moisture and carbon dioxide in the atmosphere, and magnesium hydroxide changes to magnesium carbonate. The product value is reduced for reasons such as impairing durability.

Natural products have the advantage that they can be manufactured and adjusted at low cost because the raw material is mineral and the particle size adjustment method is relatively simple, such as pulverization and classification. However, there is a problem as a powder that fine particles form strong and coarse aggregates by their surface energy when grinding is strengthened more than necessary or repeated for the purpose of eliminating coarse particles. No means for solving this has been found at present at any of the pulverization and classification methods. Moreover, since the shape of the particles becomes non-uniform when pulverized, a uniform flame retardant effect cannot be expected when the flame retardant properties are exhibited by decomposition and dehydration, which is not preferable. A method of performing a surface treatment simultaneously with pulverization by adding a surface treatment agent at the time of pulverization has been proposed, but the above problems have not been solved in terms of cost and dispersibility.
Furthermore, since natural ore is used as a raw material, there are concerns about coloring due to impurities contained therein, asbestos content, and the like, and it is difficult to remove them at low cost with the current technology. Therefore, there is a problem of losing cost merit, which is the greatest advantage of using natural products.

On the other hand, the compound magnesium hydroxide can be removed at a relatively low cost by selecting or refining raw materials other than undesired impurities such as asbestos and natural ores. Furthermore, since the particle size and dispersion | distribution of the particle | grains to produce | generate can be adjusted to some extent or more by adjusting reaction conditions, it is used especially for uses, such as an electric wire, a cable, and an electronic component, in recent years.

For example, magnesium hydroxide obtained by the method of synthesizing magnesium hydroxide proposed in Patent Document 1 has a specific shape and particle size because its crystal structure has less structural distortion than conventional magnesium hydroxide. In addition, it has features such as low secondary aggregation, excellent dispersibility, and small residual water molecules or air, and is used for the above-mentioned applications.
However, in order to satisfy the UL-94 flame retardant standard, which is one of the flame retardant indicators for electric wires, cables, etc., it must be blended in a large amount with the resin. It has the problem of reducing impact strength, elongation, tensile strength, and the like.

Patent Document 2 proposes that a composite metal hydroxide is obtained by including any one of manganese, iron, cobalt, nickel, copper, and zinc in a magnesium hydroxide crystal. By making a part of the magnesium hydroxide crystal a hydroxide of a composite metal salt, its decomposition and dehydration temperature is lowered to improve flame retardancy, and accompanying the mass mixing of magnesium hydroxide particles of Patent Document 1 It is an attempt to solve the problem. However, since the metal element taken into the crystal structure of magnesium hydroxide exists in the crystal as a hydroxide, there is a problem that the color of the particle itself is remarkably colored.
When used for molded products such as electric wires, cables, and electronic parts, the composite metal hydroxide particles of Patent Document 2 need to be blended in a relatively large amount with resin or rubber. However, in the secondary purpose of coloring and distinguishing each wire, there is a problem that it is restricted by the remarkable coloring of the particles themselves. have. It is also possible to adjust the hue by adding a hue adjuster to resin or rubber, but since the amount of magnesium hydroxide blended in the resin is large, it is also necessary to add a large amount of hue adjuster. Considering the influence on moldability, weather resistance, and durability due to this, the use of the hue adjusting agent is limited.
In addition, the metal hydroxide has a flame retardant action when its hydroxyl group decomposes and dehydrates. However, since the above metal elements have an atomic weight greater than that of magnesium, they are blended in the same proportion as conventional magnesium hydroxide. There is a problem that the number of hydroxyl groups is relatively reduced and the flame retardancy is lowered. Although it is possible to cope with the problem by increasing the blending ratio, a decrease in moldability and strength physical properties of the resin molded product due to an increase in the blending ratio becomes a new problem.
Furthermore, chlorides of the above metal elements are obtained during the reaction, but nickel, chromium, and cobalt chlorides are expensive and require strict consideration for the environment when used and disposed of. There are many problems that must be solved in order to produce and use inexpensively and in large quantities.

In Patent Document 3, the impurities and physical properties mixed as solid solution or impurities in the magnesium hydroxide particles are examined, and contrary to Patent Document 2, iron, manganese, cobalt, chromium, copper, vanadium, It has been found that if nickel is present as an impurity in a specific amount or more, it will affect the thermal degradation of the resin, and it has been proposed to strictly limit the content thereof to a specific amount or less.
However, although the particles obtained in Patent Document 3 are intended to improve the flame retardancy by improving the heat deterioration resistance when blended with a resin or rubber, the heat deterioration resistance is not necessarily sufficient, and the hue or resin The problem of adding a large amount to rubber and rubber has not been solved.

In addition, one of the recent demands for improving flame retardancy is the continuous expression of flame retardancy. Metal hydroxides such as magnesium hydroxide have the problem of lack of sustainability because they do not contribute to flame retardancy once they are decomposed and dehydrated. No improvement measures have been proposed for the problem of flame retardancy.

JP 52-115799 A JP-A-6-41441 JP-A-9-227784

In view of the actual situation, the present invention may be formulated in a relatively small amount, and therefore, it is excellent in flame retardancy and its sustainability without causing deterioration in physical properties, and imparts excellent heat deterioration resistance and hue to the resin. The present invention provides a magnesium hydroxide composition that can be used, a method for producing the same, a resin composition comprising the composition, and a molded product thereof.

As a result of intensive studies aimed at solving the above problems, the present inventors have formulated a magnesium hydroxide composition containing a specific amount of iron and / or manganese and a sulfur component into the resin. In this case, it is excellent in flame retardancy and its sustainability, and by containing a sulfur component, coloring and thermal deterioration caused by iron and manganese are suppressed, and as a result, it is difficult to impair the strength physical properties of the resin. Magnesium hydroxide composition capable of obtaining molded articles such as resin compositions, electric wires, cables, electronic parts, etc. excellent in flammability and sustainability, heat resistance deterioration and hue, manufacturing method thereof, and water thereof A resin composition obtained by blending a magnesium oxide composition and a molded product thereof have been found, and the present invention has been completed.

That is, the first of the present invention consists of magnesium hydroxide particles containing iron and / or manganese and sulfur, and the content M of iron and / or manganese measured with an atomic absorption spectrophotometer is based on the magnesium hydroxide particles. The magnesium hydroxide composition is characterized in that it is in the range of 10 to 1000 ppm, and the sulfur content S measured by the infrared absorption method is in the range of 10 to 1800 ppm with respect to the magnesium hydroxide particles.

In a preferred embodiment, the magnesium hydroxide composition is characterized in that the ratio S / M of the sulfur content S to the iron and / or manganese content M is in the range of 1.0 to 1.8.

As a more preferred embodiment, the magnesium hydroxide composition is characterized in that the whiteness W is 98 or more, the L value is 78 or more, and the b value is 3.5 or less.

Further, as a preferred embodiment, selected from fatty acids, alicyclic carboxylic acids, aromatic carboxylic acids, resin acids, metal salts thereof, amine salts thereof, esters thereof, surfactants, coupling agents, and phosphate esters. The magnesium hydroxide composition is surface-treated with at least one surface treatment agent.

Further, as a preferred embodiment, the 50% average particle size Dp ₅₀ measured with a laser diffraction / scattering particle size distribution meter is 0.5 to 2.0 μm, and the maximum particle size D _Max measured with a laser diffraction / scattering particle size distribution meter is 6. 5μm or less, and magnesium hydroxide composition characterized by nitrogen adsorption method with measured BET specific surface area Sw is 1 ~ 10m ² / g.

In the second aspect of the present invention, magnesium hydroxide particles obtained by reacting a magnesium chloride solution containing sulfate ions with a hydroxide solution, or surface-treated magnesium hydroxide particles obtained by subjecting the magnesium hydroxide particles to surface treatment, an iron chloride solution And / or a manganese chloride solution is added.

In the third aspect of the present invention, magnesium hydroxide particles obtained by reacting a magnesium chloride solution and a hydroxide solution, or surface-treated magnesium hydroxide particles obtained by surface-treating them, an iron chloride solution and / or a manganese chloride solution, A method for producing a magnesium hydroxide composition, comprising adding a solution mixed with a sulfur compound.

In a preferred embodiment, the amount of iron and / or manganese in the iron chloride solution and / or manganese chloride solution is 10 to 1000 ppm with respect to the magnesium hydroxide particles or the surface-treated magnesium hydroxide particles obtained by surface-treating the particles. It is a manufacturing method of the magnesium hydroxide composition characterized by being.

In a preferred embodiment, the ratio Sm / Mm of the number of moles Sm of sulfur in the sulfur compound to the number of moles Mm of iron and / or manganese in the iron chloride solution and / or manganese chloride solution is 1.9 to 3.3. It is a manufacturing method of the magnesium hydroxide composition characterized by the above-mentioned.

In a preferred embodiment, the method for producing a magnesium hydroxide composition is characterized in that the sulfur compound is at least one reducing agent selected from a thiosulfuric acid compound and dechlorin.

A fourth aspect of the present invention is a resin composition obtained by blending the above magnesium hydroxide composition into a resin.

A fifth aspect of the present invention is a molded product obtained by molding the above resin composition.

Since the magnesium hydroxide composition of the present invention contains a specific amount of iron and / or manganese and a sulfur component, it is excellent in flame retardancy and its sustainability when blended in a resin, and iron is added by the sulfur component. Resin composition and electric wires and cables excellent in flame retardancy and sustainability, heat resistance deterioration and hue, without inhibiting coloring and thermal deterioration caused by copper and manganese, without impairing the strength physical properties of the resin A magnesium hydroxide composition capable of obtaining a molded article such as an electronic component can be provided.

The magnesium hydroxide composition of the present invention comprises magnesium hydroxide particles containing iron and / or manganese and sulfur, and the content M of iron and / or manganese is in the range of 10 to 1000 ppm with respect to the magnesium hydroxide particles. The sulfur content S is in the range of 10 to 1800 ppm with respect to the magnesium hydroxide particles.
When the magnesium hydroxide composition of the present invention contains iron or manganese in the above range, it is incorporated into the resin, and when it exhibits its effectiveness as a flame retardant, iron or manganese released from the particle surface of the magnesium hydroxide particles. Acts as a dehydrogenation catalyst in the resin, removing the hydrogen atoms in the resin and leaving only carbon. The remaining carbon improves the flame retardancy by generating non-combustible carbon called char, and further improves the sustainability as a flame retardant by continuing to inhibit the decomposition and combustion of the resin.

When the content M of iron and / or manganese in the magnesium hydroxide composition exceeds 1000 ppm, it is preferable in terms of improvement in sustainability of flame retardancy, but coloration becomes remarkable, and further, these metals contribute to heat deterioration of the resin. Adversely affected. The reason for this is not clear, but it is unlikely that all the added iron and / or manganese will react completely with the sulfur compound, and as the added amount increases, the remaining iron and / or manganese that does not react with the sulfur compound is oxidized. It is presumed that the resin is colored or radicalized to adversely affect the thermal degradation of the resin. In addition, by increasing the weight ratio of iron and / or manganese in the magnesium hydroxide composition, the ratio of magnesium hydroxide particles that provide a relatively flame-retardant action decreases, and the resin contains sufficient flame retardancy. Can no longer be granted.
On the other hand, when the content M of iron and / or manganese is less than 10 ppm, it is preferable in terms of hue and heat deterioration, but in terms of flame retardancy, there is no significant difference from the case where magnesium hydroxide particles are used alone, and flame retardancy. The effect of improving the sex and its sustainability is reduced. The total amount M of iron and manganese is preferably 100 to 1000 ppm, more preferably 200 to 500 ppm.
In addition, content of iron and manganese was measured with Shimadzu Corporation atomic absorption spectrophotometer AA6700F.

In addition, since the magnesium hydroxide composition contains sulfur within the above range, the resin is unlikely to be thermally deteriorated despite the fact that it contains iron or manganese, and a good hue is achieved with the magnesium hydroxide of the present invention. It can be applied to a composition, a resin composition, and a molded article. The reason and mechanism for preventing thermal degradation and imparting a good hue by containing sulfur in the above range is not clear, but in the magnesium hydroxide composition, sulfur is a sulfate or sulfite of iron or manganese, It is presumed that it is in the form of complex compounds such as sulfur-containing double salts and sulfur-containing complex salts, and the activity of iron and manganese is suppressed.

When the sulfur content S exceeds 1800 ppm, the hue of the magnesium hydroxide composition itself, and the resin composition and molded body containing the magnesium hydroxide composition deteriorate. The reason why the hue deteriorates is not clear, but not only the sulfur compound reacts with iron and manganese, but also magnesium and other impurities such as calcium and sulfites are generated and the content increases. It is guessed. On the other hand, when the sulfur content S is less than 10 ppm, not only the hue is deteriorated, but also the heat deterioration property is deteriorated when the resin molded body is obtained. The reason for this is not clear, but due to the small amount of sulfur compounds, the magnesium hydroxide particles do not fully work on iron and manganese, and coloring by iron and manganese hydroxides and radicalization cannot be suppressed. It is presumed that. The sulfur content S is preferably 100 to 1800 ppm, more preferably 200 to 800 ppm.
The sulfur content was measured by an infrared absorption method, specifically, carbon manufactured by LECO and a sulfur analyzer CS-444.

The ratio S / M of the sulfur content S to the iron and / or manganese content M is preferably in the range of 1.0 to 1.8, more preferably 1.2 to 1.5.
When the ratio S / M exceeds 1.8, the hue of the magnesium hydroxide composition itself, and the resin composition and molded body containing the magnesium hydroxide composition tend to deteriorate. The reason for this tendency is not clear, but not only sulfur compounds react with iron and manganese, but also magnesium and other impurities such as calcium and sulfites are produced, and their content is high. Presumed to be.
On the other hand, when the ratio S / M is less than 1.0, not only does the hue tend to deteriorate, but also the thermal deterioration property tends to deteriorate when it becomes a resin molded body. The reason for this is not clear, but due to the small amount of sulfur compounds, the magnesium hydroxide particles do not fully work on iron and manganese, and coloring by iron and manganese hydroxides and radicalization cannot be suppressed. It is presumed that.

As for the hue of the magnesium hydroxide composition of the present invention, the whiteness W as a powder of the magnesium hydroxide composition measured with a ket type phototube whiteness meter is preferably 98 or more, more preferably 100 or more. Particularly preferably, it is 102 or more.

When the whiteness W is less than 98, the resin composition formed by blending the magnesium hydroxide composition of the present invention and the molded body prepared therefrom are colored by the magnesium hydroxide composition. In some cases, it is preferable to adjust the hue, so that the strength of the molded body tends to be reduced accordingly.
The whiteness W was measured with a powder whiteness meter C-100-3 manufactured by KETT.

In addition, the magnesium hydroxide composition is dispersed in di-2-ethylhexyl phthalate (hereinafter abbreviated as DOP) at a ratio of 1: 2, and the color of the mixture (hereinafter abbreviated as DOP wet color) is expressed in Hunter Lab color. The L value when expressed in a system is preferably 78 or more, more preferably 80 or more, and still more preferably 81.5 or more.
Furthermore, the b value of the DOP wet color is preferably 3.5 or less, more preferably 2.8 or less, and still more preferably 2.0 or less.

When the L value is less than 78 or when the b value exceeds 3.5, the resin composition formed by blending the magnesium hydroxide composition and the molded body produced therefrom are affected by the hue of the magnesium hydroxide composition. Since it is colored, there may be a case where it is unavoidable to add a colorant or the like to adjust the hue for this correction, so that the strength and the like of the molded product tend to be weakened.
In addition, the measurement by the Hunter Lab color system in this invention was measured by Nippon Denshoku Industries Co., Ltd. colorimetric color difference meter ZE2000.

The magnesium hydroxide composition of the present invention preferably satisfies specific particle size characteristics. That is, the 50% average particle diameter Dp _{50 of the} magnesium hydroxide composition measured by a laser diffraction / scattering particle size distribution meter is preferably 0.5 to 2.0 μm, more preferably 0.5 to 1.5 μm, More preferably, it is in the range of 0.5 to 1.2 μm, and the maximum particle diameter D _Max of the magnesium hydroxide composition measured by a laser diffraction / scattering particle size distribution meter is preferably 6.5 μm or less. preferably 5.5μm or less, more preferably in the range of not less than 4.5 [mu] m, further preferably a BET specific surface area Sw by a nitrogen adsorption method is 1 ~ 10m ² / g, more preferably 2 ~ 7m ² / It is preferable to be in the range of g.

When the magnesium hydroxide composition of the present invention satisfies the above-mentioned 50% average particle diameter Dp ₅₀ , maximum particle diameter D _Max , and BET specific surface area Sw, it is blended into a resin and exhibits its effectiveness as a flame retardant. At this time, it can be dispersed throughout the resin, and since it is finer, it has a large area in contact with the particles in the event of a fire and is effective as a flame retardant because it can be easily dehydrated by decomposition of hydroxyl groups. Further, in order to exhibit the effect as a flame retardant, the shape of the particles is preferably a flat shape.

When the 50% average particle diameter Dp ₅₀ is less than 0.5 μm, the surface energy of the particles increases because of being too fine, and aggregates and stabilizes. Therefore, when blending into a resin or molding a resin composition Aggregates are easily generated. Further, when large particles that are strongly aggregated are present in the resin molded product, there are cases where the surface of the molded product has more spots and convex portions than the fine, uniform, and dispersible particles, and the appearance may be impaired. Furthermore, the detailed mechanism of strength properties such as impact resistance and tensile strength is not clear at present. However, if large particles are present in the resin, the stress is applied to the molded body in the same way as when the resin is stressed. Since it does not absorb, peeling at the resin interface and particle destruction may occur, and the strength of the resin molded body may not satisfy desired physical properties. Furthermore, the particles are easily exposed on the surface of the molded article, and take in moisture and carbon dioxide in the atmosphere, and the magnesium hydroxide changes into magnesium carbonate. There are cases where problems such as separation occur and the durability of the molded article decreases. In addition, in the case of small particles of less than 0.5 μm, it is difficult to carry iron and / or manganese uniformly on the surface of all the particles with the current technology, so it is blended in resin compositions and molded products. In this case, it tends to be inferior in terms of imparting flame retardancy.
On the other hand, when the average particle diameter Dp ₅₀ exceeds 2.0 μm, large particles are present in the resin molded product, so that the appearance of the molded body is impaired as in the case where the average particle diameter Dp ₅₀ is less than 0.5 μm. In some cases, problems such as deterioration of strength properties such as impact resistance and tensile strength and deterioration of durability may occur.

When the maximum particle diameter D _Max exceeds 6.5 μm, a large number of coarse particles are present in the resin regardless of single particles or agglomerated particles. As in the case where the average particle diameter Dp ₅₀ exceeds 2.0 μm, there is a tendency that the appearance of the molded body is impaired, the strength physical properties such as impact resistance and tensile strength are lowered, and the durability is lowered.
The 50% average particle diameter Dp ₅₀ and the maximum particle diameter D _Max were measured using a Microtrac FRA laser diffraction / scattering particle size distribution meter manufactured by Lees & Northrup, with the solvent as methanol.

When the BET specific surface area Sw is less than 1 m ² / g, a large number of single particles are present in the magnesium hydroxide composition, and as in the case where the average particle diameter Dp ₅₀ exceeds 2.0 μm, There is a tendency for the appearance of the molded article to be impaired, causing problems such as a reduction in strength properties such as impact resistance and tensile strength, and a reduction in durability.
On the other hand, when the Sw exceeds 10 m ² / g, fine particles increase in the magnesium hydroxide composition, and aggregates are formed when the resin composition is molded during storage or compounding into a resin. As in the case where the average particle diameter Dp ₅₀ exceeds 2.0 μm, the appearance of the molded body is impaired, the strength physical properties such as impact resistance and tensile strength are lowered, and the durability is lowered. Tend to occur.
The nitrogen adsorption BET specific surface area was measured with NOVA2000 manufactured by Yuasa Ionics Co., Ltd.

The magnesium hydroxide composition of the present invention, when blended in a resin composition, improves various physical properties such as durability and strength, and improves particle stability, dispersibility, affinity with resin and imparts water repellency. For the purpose. It is preferable to perform surface treatment (coating) with a surface treatment agent. Examples of such surface treatment agents include fatty acids, alicyclic carboxylic acids, aromatic carboxylic acids, resin acids, salts of these metal salts, amine salts, esters thereof, surfactants, coupling agents, and phosphoric acid. An ester etc. are mentioned, These are used individually or in combination of 2 or more types as needed.
The above-mentioned surface treatment agent may be appropriately selected from the viewpoints of the above various physical properties, applications, environmental influences, handling properties, and cost. For example, EEA or EVA resin used as a resin for coating eco wires For applications, surface treatment with fatty acids, metal salts thereof, and silane coupling agents is preferable from the viewpoint of hue, and silane coupling agents are more suitable for demands of hue and recent flame retardancy and strength properties. 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 acids such as naphthenic acid; benzene carboxylic acids such as benzoic acid and phthalic acid; aromatic carboxylic acids such as naphthoic acid and naphthalene carboxylic acid such as naphthalic acid; abietic acid and pimaric acid Resin acids such as parastrinic acid and neoabietic acid. And reactivity with Neshiumu, particle stability, dispersibility, mixed acid stearic acid and palmitic acid are preferable in terms of cost.

Examples of fatty acid, alicyclic carboxylic acid, aromatic carboxylic acid, metal salt of resin acid, and amine salt include potassium laurate, potassium myristate, potassium palmitate, sodium palmitate, barium stearate, calcium stearate, stearin. Saturated fatty acid salts such as zinc oxide, potassium stearate, cobalt (II) stearate, tin (IV) stearate, sodium stearate, lead (II) stearate; zinc oleate, potassium oleate, cobalt oleate (II) ), Unsaturated fatty acid salts such as sodium oleate and potassium diethanolamine salt; alicyclic carboxylates such as lead naphthenate and lead cyclohexylbutyrate; aromatic carboxylates such as sodium benzoate and sodium salicylate; sodium abietate, Abbie Potassium phosphate, sodium pimaric acid, potassium pimaric acid, sodium palustric acid, potassium palustric acid, sodium neoabietic acid, resin acid salts such as potassium neoabietic acid.

Further, prior to the surface treatment or surface treatment of the magnesium hydroxide particles of the present invention, the previously described fatty acid, alicyclic carboxylic acid, aromatic carboxylic acid, resin acid, lithium, sodium, potassium, rubidium, beryllium , Magnesium, Calcium, Strontium, Barium, Zinc, Aluminum, Lead, Cobalt, Tin, Compounds with acyl group are mixed and reacted to make fatty acid, alicyclic carboxylic acid, aromatic carboxylic acid, metal salt of resin acid, amine You may make a salt suitably.

Among the above fatty acid, alicyclic carboxylic acid, aromatic carboxylic acid, and resin acid metal salts, stearic acid or palmitic acid is mainly used in terms of reactivity with magnesium hydroxide, particle stability, dispersibility, and cost. The use of mixed soap as a component is preferred.

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, stearyl Saturated fatty acid esters such as methyl phosphate, butyl stearate, octyl stearate, stearyl stearate, cholesteryl stearate, isocetyl isostearate, methyl behenate, behenyl; methyl oleate, ethyl linoleate, isopropyl, ethyl olive oleate, Unsaturated fatty acid esters such as 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, isocetyl 12-stearoyl stearate, isostearyl 12-stearoyl stearate, stearyl 12-stearoyl stearate, beef tallow fatty acid octyl ester Heat-resistant special fatty acid esters such as Cole fatty acid esters / alkyl glyceryl ether fatty acid esters; aromatic esters represented by benzoic acid esters, among others, reactivity with magnesium hydroxide, particle stability, and dispersibility From the viewpoint of cost, the use of polyhydric alcohol stearic acid or palmitic acid or stearyl stearate of polyhydric alcohol fatty acid ester is preferable.

As the surfactant, a group consisting of a polymer of a monomer having a vinyl group and its alkali metal salt, ammonium, and a partially or completely neutralized product with an amine, for example, α, β-monoethylenic monomer. Unsaturated monocarboxylic acid, α, β-monoethylenically unsaturated dicarboxylic acid, methacrylic acid alkyl ester, (meth) acrylic ether having alkoxy group, (meth) acrylate having cyclohexyl group, α, β-monoethylenically unsaturated Saturated hydroxy ester, polyalkylene glycol mono (meta) acrylate, vinyl ester, vinyl aromatic, unsaturated nitrile, unsaturated dicarboxylic acid ester, vinyl ether, conjugated diene, chain olefin, cyclic olefin, sulfo group-containing monomer, etc. Can be mentioned. In addition, as another type of surfactant, alkyl ether sulfuric acid, alkyl ether phosphoric acid, alkyl aryl ether sulfuric acid, alkyl aryl ether phosphoric acid, alkyl sulfuric acid ester, alkyl phosphoric acid ester, alkyl aryl sulfuric acid, alkyl aryl phosphoric acid, alkyl Amidosulfuric acid ester, alkylsulfonic acid, alkylbenzenesulfonic acid, alkylnaphthalenesulfonic acid, sulfosuccinic acid, sulfosuccinic acid ester, α-olefin sulfonic acid, N-acylsulfonic acid, N-acylamino acid, alkyl ether carboxylic acid, acylation Peptide, aliphatic amine, aliphatic quaternary amine, aromatic quaternary ammonium, betaine, aminocarboxylic acid, imidazoline derivative, alkyl ether, alkyl allyl ether, alkyl discarded, alkyl amine Emissions, sorbitan derivatives, polycyclic phenyl ether, aliphatic ester, fluoroalkyl carbon acids, perfluoroalkyl carbon acid, perfluoroalkylsulfonic acid, acetylene alcohol, acetylene glycol, and the like. Among these, sulfates such as alkyl ether sulfuric acid, alkyl aryl ether sulfuric acid, alkyl sulfuric acid ester, sulfuric acid ether, sulfuric acid ester, in terms of dispersibility and stability of magnesium hydroxide particles themselves, improved affinity with resin, and cost. Is preferred.

Examples of silane coupling agents include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyl, tris (β-methoxyethoxy) silane, γ-chloropropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane , Β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -Γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, and the like. In terms of dispersibility and stability of magnesium hydroxide particles themselves, improved affinity with resin, and cost, vinyltrimethoxy Silane and β- (3,4- Carboxymethyl-cyclohexyl) ethyltrimethoxysilane, 3-methacryloxy use of trimethoxysilane is preferred.

Examples of phosphate esters include trimethyl phosphate, triethyl phosphate, tributyl phosphate, 2-ethylhexyl phosphate, butoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, Cresyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, cresyl di-2,6-xylenyl phosphate, resorcinol diphenyl phosphate, various aromatic condensed phosphates, 2-chloroethyl-chloropropyl phosphate, dichloropropyl phosphate, tribromoneopentyl Phosphate, halogen-containing condensed phosphoric acid, bis-2-ethylhexylphos Phosphate, diisodecyl phosphate, 2-methacryloyloxyl ethyl acid phosphate, diphenyl-2-methacryloyloxyethyl phosphate, methyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, dibutyl phosphate, monobutyl phosphate, 2-butylhexyl acid phosphate, isodecyl Acid phosphate, monoisodecyl phosphate, triphenyl phosphite, dibutyl hydrogen phosphite, dibutyl hydrogen phosphite, diphenyl phosphorochloridate, phenyl phosphorodichloridate, polyoxyethylene lauryl ether phosphate, 12 to 12 alkyl groups 26 polyoxyalkyl ether phosphates, polyoxyethylene alkyl phosphates Nyl ether phosphoric acid, polyoxyethylene dialkyl phenyl ether phosphoric acid, etc. Use of triethyl phosphate or tributyl phosphate in terms of dispersibility and stability of magnesium hydroxide particles themselves, improved affinity with resin, and cost Is preferred.

The amount of the surface treatment agent to be treated is appropriately selected depending on the type and use of the resin used in the resin composition obtained in the present invention. For example, when blended in a synthetic resin, the amount is 100 parts by weight of the particles. The amount is usually 0.01 to 10 parts by weight, preferably 0.05 to 8 parts by weight.
When the treatment amount of the surface treatment agent is less than 0.01 parts by weight, the effect of improving the handling during the production of the resin composition or the molded product is not recognized, and the magnesium hydroxide particles in the unsurface-treated part in the resin The effect of the surface treatment agent is not recognized, as in the case of untreated magnesium hydroxide particles, such as whitening that moisture adsorbs and reacts with the carbon dioxide gas dissolved in the atmosphere to cause whitening. On the other hand, when the surface treatment amount exceeds 10 parts 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.

The action and effect of the magnesium hydroxide composition of the present invention can be appropriately selected depending on the purpose of use. For example, when the flame retardancy is more important than the hue, a magnesium hydroxide composition having a high content of iron and / or manganese and sulfur is selected for the purpose of greatly improving the flame retardancy, or flame retardancy For the purpose of placing more emphasis on hue, it is possible to select a magnesium hydroxide composition having a low content of iron and / or manganese and sulfur. It is also possible to select a magnesium hydroxide composition having an improved hue and flame retardancy, which is intermediate between the two.

As a preferable method for producing the magnesium hydroxide composition of the present invention, for example, after mixing a magnesium chloride solution and a hydroxide solution such as sodium hydroxide, calcium hydroxide, ammonium hydroxide in a certain ratio, Then, hydrothermal reaction is performed in an autoclave at 120 ° C. or more for 2 hours or more, and a method of dehydration and washing as appropriate, or slaked lime is added to seawater to obtain magnesium hydroxide particles, which are calcined to produce magnesium oxide And then reacting with water to obtain magnesium hydroxide particles. Any of these methods may be used, but the former method is preferable from the viewpoints of particle size, dispersibility, impurity content, hue, and cost. In addition, although the upper limit of temperature and time is not particularly limited, from the viewpoint of energy cost and productivity, about 300 ° C. and about 8 hours are preferable, and further, the lower the temperature and the shorter the time.

Iron and / or manganese is preferably added after the production of magnesium hydroxide particles for the purpose of increasing the probability of existing on the surface of the magnesium hydroxide particles. About a sulfur component, you may exist in the magnesium chloride which is a raw material, and may add after the production | generation of magnesium hydroxide particle | grains similarly to iron and / or manganese.

As for magnesium chloride, bitter juice produced as a by-product during salt production from seawater can be obtained easily and inexpensively, but it is necessary to desulfurize it and further remove trace impurities such as potassium chloride. However, since the magnesium hydroxide composition of the present invention can use sulfate ions contained in bitter juice, it is advantageous because the cost and labor required for its removal can be reduced.

However, from the viewpoint of the influence on the hue of the obtained magnesium hydroxide composition and the resin composition obtained by blending it, and its molded product, and heat resistance deterioration, a sulfur component should also be added after the production of magnesium hydroxide particles. Is preferred. Which method should be selected may be selected in consideration of the cost required for them, handling, and physical properties of the particles obtained.
When the sulfur component is added after the production of magnesium hydroxide particles, it is preferably carried out simultaneously with the addition of iron and / or manganese. In particular, the iron chloride solution and the solution containing the sulfur component are mixed in advance, and the magnesium hydroxide particles or the surface is added. More preferably, it is added to the treated magnesium hydroxide particles and supported on the surface thereof.

The content of iron and / or manganese in the iron chloride solution and / or manganese chloride solution added to the magnesium hydroxide particles or the surface-treated magnesium hydroxide particles is in the range of 10 to 1000 ppm with respect to the magnesium hydroxide particles. Preferably, it is in the range of 100 to 1000 ppm, more preferably in the range of 200 to 500 ppm. When the iron and / or manganese content is less than 10 ppm, the flame retardancy is not sufficient. On the other hand, when the content exceeds 1000 ppm, the hue of the magnesium hydroxide composition itself, the resin composition containing the same and the molded product tends to deteriorate. There is.

For sulfur compounds added simultaneously or in advance with the iron chloride solution and / or manganese chloride solution, the number of moles of sulfur in the sulfur compound relative to the number of moles of iron and / or manganese in the iron chloride solution and / or manganese chloride solution Mm The Sm ratio Sm / Mm is preferably in the range of 1.9 to 3.3, and more preferably in the range of 2.1 to 2.8. When the molar ratio Sm / Mm is less than 1.9, the hue and heat deterioration of the magnesium hydroxide composition itself, the resin composition and molded product containing the magnesium hydroxide composition are deteriorated. Tend to get worse.

More preferably, the sulfur compound is a reducing agent selected from one or more of thiosulfuric acid and dechlorin.
Examples of thiosulfate-based reducing agents include hydrosulfite (sodium hyposulfite), Rongalite C (sodium formaldehyde sulfoxylate), Rongalite Z (zinc formaldehyde sulfoxylate), hypo (sodium thiosulfate), sulfite (sulfurous acid) Sodium), sulfur monosulfide, hydroxylamine sulfate, etc., but hypo and hydrosulfite are preferable in terms of environment, cost, and handling, and hydrosulfite is particularly preferable in terms of cost because hydrosulfite is effective in a small amount. Used.

In the method for producing a magnesium hydroxide composition of the present invention, an iron chloride solution and / or a solution prepared by previously mixing a manganese chloride solution and a sulfur compound is added to either magnesium hydroxide particles or surface-treated magnesium hydroxide particles. In addition, it may be added together with the surface treatment agent during the surface treatment.
Furthermore, even when magnesium hydroxide particles or surface-treated magnesium hydroxide particles are in a dry powder or suspension state, they are effective in improving the hue of the particles and the hue when blended with the resin, and flame retardancy. Show.
However, it is advantageous in terms of handling when magnesium hydroxide particles are subjected to wet surface treatment and then a solution in which a sulfur compound is mixed in advance in an iron chloride solution and / or a manganese chloride solution is dried. When used, it is good in terms of flame retardancy and hue.
Although it is not clear about these mechanisms, the uniformity of their loading on magnesium hydroxide particles or surface-treated magnesium hydroxide particles is further improved by adding iron and / or manganese after surface treatment in a wet manner. It is estimated that

In order to adjust the total amount M of iron and manganese contained in the magnesium hydroxide composition to 10 to 1000 ppm based on the magnesium hydroxide particles, iron (II) chloride, iron (III) chloride or manganese chloride iron or manganese is added. It may be adjusted by dissolving in water so as to be in the above range.

Further, in order to adjust the amount S of sulfur contained in the magnesium hydroxide composition to 10 to 1800 ppm with respect to the magnesium hydroxide particles, when using sulfate ions in bitter juice, the amount of sulfate ions in bitter juice was determined. Later, sulfate ions other than the required amount may be removed by adding calcium chloride or barium chloride to precipitate calcium sulfate or barium sulfate. Moreover, when using a sulfur compound, what is necessary is just to melt | dissolve and adjust the sulfur content of the sulfur compound to be used in the water which melt | dissolved iron chloride or manganese chloride in the above-mentioned range.

In order to adjust the average particle diameter Dp ₅₀ of the magnesium hydroxide composition to a range of 0.5 to 2.0 μm, the molar ratio of magnesium in the magnesium chloride solution to be mixed to the hydroxyl group in the hydroxide solution is 1: 2. ~ 2: 3, the temperature of both liquids is 20 ° C ± 10 ° C, and the hydroxide solution is added dropwise to the magnesium chloride solution within 1 to 15 minutes while stirring, and then the temperature rises to 120 ° C or higher within 4 hours by autoclave. It is preferable to warm and hold at that temperature for 1 hour or longer. These conditions have been found to affect each other. For example, when the molar ratio of magnesium to hydroxyl group approaches 1: 2 or 2: 3, Dp ₅₀ tends to increase and tends to approach 2.0 μm. . When the liquid temperature of both liquids approaches 10 ° C. or 30 ° C., Dp ₅₀ increases and tends to approach 2.0 μm. Stirring should be appropriately selected depending on the amount of liquid, but if the stirring force is too strong or too weak, Dp ₅₀ tends to increase and approach 2.0 μm. Regarding the temperature rise in the autoclave, when the time to reach 120 ° C. or higher is short, Dp ₅₀ tends to decrease and approaches 0.5 μm, and when close to 4 hours, Dp ₅₀ increases and is close to 2.0 μm. Tend to be. When the retention time at 120 ° C. or higher in the autoclave is short, Dp ₅₀ tends to increase, and when it is less than 1 hour, Dp ₅₀ exceeds 2.0 μm, and when the retention time increases, the particle size tends to decrease. Although there is no significant change in Dp ₅₀ even after holding for 8 hours or more.

In order to adjust the maximum particle diameter D _Max of the magnesium hydroxide composition to 6.5 μm or less, the magnesium in the magnesium chloride solution to be mixed and the hydroxyl groups in the hydroxide solution are mixed as in the case of the average particle diameter Dp ₅₀ . The molar ratio was 1: 2 to 2: 3, the temperature of both solutions was 20 ° C. ± 10 ° C., and the hydroxide solution was added dropwise to the magnesium chloride solution within 1 to 15 minutes while stirring. It is preferable that the temperature is raised to 120 ° C. or higher within the time and maintained at that temperature for 1 hour or longer. These conditions have been found to affect each other. For example, when the molar ratio of magnesium to hydroxyl group approaches 1: 2 or 2: 3, D _Max tends to be close to a large value of 6.5 μm. . When the liquid temperature of both liquids approaches 10 ° C. or 30 ° C., D _Max increases and tends to be close to 6.5 μm. Stirring should be appropriately selected depending on the amount of the liquid, but D _Max tends to increase and approach 6.5 μm even if the stirring force is too strong or too weak. For heating in an autoclave, D _Max decreases the short time to reach the above 120 ° C., the D _Max approaches the 4 hours tend to become closer to the larger becomes 6.5 [mu] m. When the holding time at 120 ° C. or higher in the autoclave is short, D _Max tends to increase. When it is less than 1 hour, D _Max exceeds 6.5 μm, but when the holding time is increased, D _Max tends to decrease. There is.

In order to adjust the BET specific surface area Sw of the magnesium hydroxide particles to 1.0 to 10 m ² / g, similarly to the average particle diameter Dp ₅₀ and the maximum particle diameter D _Max , magnesium and hydroxide in the mixed magnesium chloride solution are mixed. The hydroxide solution was added dropwise to the magnesium chloride solution within 1 to 15 minutes while stirring, with the molar ratio of hydroxyl groups in the product solution being 1: 2 to 2: 3, the liquid temperature of both solutions being 20 ° C. ± 10 ° C., Furthermore, it is preferable that the temperature is raised to 120 ° C. or higher within 4 hours in an autoclave and maintained at that temperature for 1 hour or longer. It has been found that these conditions influence each other. For example, when the molar ratio of magnesium and hydroxyl group approaches 1: 2, Sw increases and approaches 10 m ² / g, and when approaching 2: 3, S increases. w tends to decrease and approach 1 m ² / g. When the liquid temperature of both liquids approaches 10 ° C., Sw increases and approaches 10 m ² / g, and as it approaches 30 ° C., Sw decreases and tends to approach 1 m ² / g. Stirring should be appropriately selected depending on the amount of liquid, but if the stirring force is too strong or too weak, the Sw will increase and tend to approach 10 m ² / g. Regarding the temperature rise in the autoclave, if the time to reach 120 ° C. or higher is short, Sw becomes small, and if it approaches 4 hours, Sw tends to approach 10 m ² / g. If the holding time at 120 ° C. or higher in the autoclave is short, Sw tends to increase, and if it is less than 1 hour, Sw exceeds 10 m ² / g. If the holding time is lengthened, Sw tends to be small, but even if it is lengthened for 8 hours or more, there is no significant change in Sw.

A surface-treated or untreated suspension of magnesium hydroxide composition to which iron chloride and / or manganese chloride and a sulfur compound are added may be washed, dehydrated, granulated, dried, pulverized, classified, etc., if necessary. By appropriately selecting the means, a final product form as a magnesium hydroxide composition is obtained.

The magnesium hydroxide composition of the present invention obtained as described above is blended with various resins to form a resin composition. The magnesium hydroxide composition of the present invention is blended in a proportion of preferably 15 to 80 wt%, more preferably 20 to 70 wt%, based on the total weight with the resin.
The resin used in the resin composition of the present invention may be any resin as long as it is usually used as a molded product, and examples thereof include thermoplastic resins, thermosetting resins, and synthetic rubbers.

Thermoplastic resins include polyolefins such as polymers or copolymers of C2 to C8 olefins (α-olefins) such as polyethylene, polypropylene, ethylene / propylene copolymers, polybutene, poly-4-methylpentene-1, etc. Resin, olefin and diene copolymer, ethylene-acrylate copolymer, polystyrene, ABS resin, AAS resin, AS resin, MBS resin, ethylene-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, ethylene -Vinyl chloride-vinyl acetate copolymer, polyvinylidene chloride, polyvinyl chloride, chlorinated polyethylene, chlorinated polypropylene, vinyl chloride-propylene copolymer, polyvinyl acetate, phenoxy resin, polyacetal, polyamide, polyimide, polycarbonate, polysulfone , Poly E two alkylene oxide, polyphenylene sulfide, polyethylene terephthalate, polybutylene terephthalate, and methacrylonitrile based resins.
Among these thermoplastic resins, preferred examples of the resin composition of the present invention include polyolefin resins or copolymers thereof. Among them, resins used for various general-purpose electric wires and cables such as EEA resins and EVA resins. When used, it is suitable because it provides mechanical strength in addition to hue and flame retardancy.

Examples of the thermosetting resin include an epoxy resin, a phenol resin, a melamine resin, an unsaturated polyester resin, an alkyd resin, and a urea resin. Examples of the synthetic rubber include EPDM, butyl rubber, isoprene rubber, SBR, NBR, chlorosulfonated polyethylene, NIR, urethane rubber, butadiene rubber, acrylic rubber, silicone rubber, and fluorine rubber.

Although the resin composition of the present invention has excellent flame retardancy, the blending ratio of the magnesium hydroxide composition particles of the present invention can be reduced by further adding a flame retardant aid, and the flame retardant effect is further improved. It can be made.
As the flame retardant aid, red phosphorus, carbon powder or a mixture thereof is preferable. As red phosphorus, for example, red phosphorus whose surface is coated with a thermosetting resin, polyolefin, carboxylic acid polymer, titanium oxide, titanium aluminum condensate, or the like can be used in addition to normal red phosphorus for a flame retardant. Examples of the carbon powder include carbon black, activated carbon, and graphite. The carbon black may be prepared by any method of an oil furnace method, a channel method, a thermal method, or an acetylene method.
When the flame retardant aid is blended, it is preferably added in the range of 0.5 to 20 wt%, more preferably 1 to 15 wt% with respect to the entire resin composition.

In the resin composition 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, crosslinking agents, light stabilizers, ultraviolet absorbers, and lubricants. Depending on the purpose, for the purpose of further improving the flame retardancy, it can be used in combination with a flame retardant such as bromine, phosphorus, nitrogen or inorganic metal other than magnesium hydroxide particles.

The resin composition of the present invention is formed into a molded product by various molding methods.
The molded article of the present invention can be obtained from the resin composition obtained as described above by a known method such as extrusion molding, injection molding or calendar molding.
According to the molded article of the present invention, since the magnesium hydroxide composition of the present invention is blended, the flame retardancy and its continuity are excellent, and the appearance of the molded article is also excellent. Applications of such molded products include wire coverings such as the above-mentioned electric wires and cables, housings for home appliances, wallpaper for building materials, foam insulation, mattresses, connector connection parts for electrical and electronic components, semiconductors Sealing material, prepreg, multilayer circuit board, laminated board for circuit board, and the like.

Hereinafter, the present invention will be described in detail based on examples and comparative examples. However, the present invention is not limited to these examples.
In the examples and comparative examples of the present invention, the average particle size and the maximum particle size of the magnesium hydroxide composition were measured with a Microtrac FRA laser diffraction scattering particle size distribution meter manufactured by Lees & Northrup, and the BET specific surface area was Measured with NOVA2000 manufactured by Ionics Co., Ltd. The iron and manganese contents were measured with an atomic absorption spectrophotometer AA6700F manufactured by Shimadzu Corporation. Sulfur was measured with carbon and sulfur analyzer CS-444 manufactured by LECO. The whiteness was measured with a powder whiteness meter C-100-3 manufactured by KETT, and the DOP wet color was measured with a colorimetric color difference meter ZE2000 manufactured by Nippon Denshoku Industries Co., Ltd.

First, the magnesium chloride solution used as a raw material for the magnesium hydroxide particles in Examples and Comparative Examples of the present invention was prepared by the method described below.
<Preparation of magnesium chloride solution 1>
The salt water collected from the salt fields is roughly purified by removing foreign substances and humic substances by sand filtration and adsorption with activated carbon, and then the sulfate ion and equimolar calcium chloride contained in the brine after rough purification are brined. In addition to the above, sulfate ions in brine were precipitated as calcium sulfate and filtered to remove calcium sulfate, thereby producing a purified bitter solution containing magnesium chloride as a main component.
The obtained purified bitter solution was a magnesium chloride solution with a Baume specific gravity of 1.33 and contained 2360 ppm of sulfur with respect to magnesium chloride.

<Preparation of magnesium chloride solution 2>
The salt water collected from the salt fields is roughly purified by removing foreign substances and humic substances by sand filtration and adsorption with activated carbon, and then the sulfate ion and equimolar barium chloride contained in the brine after rough purification are brined. In addition to this, sulfate ions in the brine were precipitated as barium sulfate, filtered to remove calcium sulfate, and a purified bitter solution containing magnesium chloride as a main component was prepared.
The obtained purified bitter solution was a magnesium chloride solution with a Baume specific gravity of 1.33 and contained 0.8 ppm of sulfur with respect to magnesium chloride.

<Preparation of hydroxide solution>
Limestone was calcined with kerosene to obtain quicklime, and industrial lime milk obtained by digesting it was removed with a sieve or the like to adjust its concentration to 12 wt%. The resulting lime milk is a solution made of calcium hydroxide, and is cheaper because it is for industrial use, but it is burned with kerosene, so it is far more impure than those burned with anthracite or coke. Less is.

Example 1
Barium chloride corresponding to 90% of the number of moles of sulfur remaining in the magnesium chloride solution 1 was added to the bitter solution to precipitate barium sulfate, followed by filtration and further concentration or dilution to obtain a chloride with a Baume specific gravity of 1.3. A magnesium solution was prepared.
5 L of the obtained solution was charged into a 10 L autoclave to adjust the liquid temperature to 20 ° C., and 5 L of lime milk having a concentration of 12 wt% adjusted to the liquid temperature of 20 ° C. was added over 5 minutes under stirring conditions. And calcium hydroxide are reacted to form magnesium hydroxide particles, and after the addition of lime milk, the autoclave is heated with stirring, and the liquid temperature in the autoclave is increased to 160 ° C. over 2 hours and 4 hours. Maintained.
After that, cooling by natural heat dissipation is performed, and the resulting reaction suspension of magnesium hydroxide particles is dehydrated with a centrifugal dehydrator, washed with tap water, and the electrical conductivity of the waste water is higher than the electrical conductivity of tap water. Washing was terminated when it dropped to a level as high as 20 μS / cm.
Vinyl trimethoxysilane equivalent to 0.5 wt% with respect to the magnesium hydroxide particles in the magnesium hydroxide particle suspension is mixed and dissolved in a 1 wt% acetic acid solution, and the vinyl triethoxylane-acetic acid mixed solution is dissolved in water. Surface treatment was performed by adding to the magnesium oxide particle suspension.
Further, iron (III) chloride whose iron content is 210 ppm with respect to the magnesium hydroxide particles in the magnesium hydroxide particle suspension is added to the magnesium hydroxide particle suspension, and after sufficient stirring, the suspension The liquid was dried with a spray dryer to obtain a magnesium hydroxide composition.
Table 1 shows the preparation conditions and various physical properties of the obtained magnesium hydroxide composition.

Examples 2-7
A magnesium hydroxide composition was prepared in the same manner as in Example 1 except that the conditions described in Table 1 were changed. Table 1 shows the preparation conditions and various physical properties of the obtained magnesium hydroxide composition.
In Example 2, iron (III) chloride corresponding to an iron content of 450 ppm and manganese chloride corresponding to a manganese content of 45 ppm were added.

Example 8
A magnesium hydroxide composition was prepared in the same manner as in Example 1 except that the charging time of lime milk charged into the magnesium chloride solution in the autoclave was changed to 12 minutes. Table 1 shows the preparation conditions and various physical properties of the obtained magnesium hydroxide composition.

Example 9
The magnesium chloride solution 2 was diluted to prepare a magnesium chloride solution having a Baume specific gravity of 1.3, and 5 L of the obtained solution was charged into a 10 L autoclave to adjust the liquid temperature to 20 ° C., and the liquid temperature was adjusted to 20 ° C. Add 5 liters of lime milk with a concentration of 12 wt% over 5 minutes under stirring conditions, react magnesium chloride with calcium hydroxide to produce magnesium hydroxide, and heat the autoclave while stirring after the lime milk is charged. The liquid temperature in the autoclave was raised to 160 ° C. in 2.5 hours and then maintained for 4 hours.
Then, cooling by natural heat dissipation is performed, and the resulting magnesium hydroxide particle reaction suspension is dehydrated with a centrifugal dehydrator. After dehydration, it is washed with tap water. The test was terminated when the pressure dropped to a level 20 μS / cm higher than the degree.
Vinyl trimethoxysilane equivalent to 0.5 wt% with respect to the magnesium hydroxide particles in the magnesium hydroxide particle suspension is mixed and dissolved in a 1 wt% acetic acid solution, and the vinyl triethoxylane-acetic acid mixed solution is dissolved in water. Surface treatment was performed by adding to the magnesium oxide suspension.
Further, iron (III) chloride whose iron content is 210 ppm with respect to the magnesium hydroxide particles in the surface-treated magnesium hydroxide particle suspension is 2.2 times the number of moles of iron (III) chloride. The hydrosulfite containing sulfur is dissolved in 100 g of water, added to the magnesium hydroxide particle suspension, and after sufficient stirring, the suspension is dried with a spray drier to obtain a magnesium hydroxide composition. Got.
Table 2 shows the preparation conditions and various physical properties of the obtained magnesium hydroxide composition.

Examples 10-15
A magnesium hydroxide composition was prepared in the same manner as in Example 9 except that the conditions described in Table 2 were changed. Table 2 shows the preparation conditions and various physical properties of the obtained magnesium hydroxide composition.

Example 16
A magnesium hydroxide composition was prepared in the same manner as in Example 1 except that the charging time of the lime milk charged into the magnesium hydroxide solution in the autoclave was changed to 12 minutes.
Table 2 shows the preparation conditions and various physical properties of the obtained magnesium hydroxide composition.

Comparative Examples 1-7
A magnesium hydroxide composition was prepared in the same manner as in Example 1 except that the conditions described in Table 3 were changed. Table 3 shows the preparation conditions and various physical properties of the obtained magnesium hydroxide composition.

Examples 17 to 32, Comparative Examples 8 to 14
125 parts of the magnesium hydroxide compositions obtained in Examples 1 to 16 and Comparative Examples 1 to 7 were added to 100 parts by weight of ethylene-ethyl acrylate resin (trade name EVAFLEX-EEA) manufactured by Mitsui, DuPont Polychemical Co., Ltd. 2 parts calcium stearate as a lubricant, 0.2 part by weight of Adeka Stub AO-60 manufactured by Asahi Denka Kogyo Co., Ltd. as a stabilizer, and a laboratory blast mill 4C150-01 manufactured by Toyo Seiki Seisakusho Co., Ltd. The resin composition was obtained by kneading with 2D25W.
The obtained resin composition was press-molded at 150 ° C. to prepare a 3 mm thick sheet.

<Hue evaluation of molded resin>
The obtained sheet was molded into a flat plate of 40 mm in length and width, the whiteness W was measured, and represented by L value and b value of Hunter Lab color system.
<Flame retardance evaluation of resin moldings>
A test piece having a length of 150 mm and a width of 6.5 mm was prepared as a molded body for a combustion test by the oxygen index method, and the oxygen index was measured in accordance with JISK7201. Further, during the measurement of the oxygen index of the compact, the degree of char formation was visually observed. Furthermore, regarding the flame retardancy, in accordance with ASTM E1354, the heat generation rate is obtained using a corn calorimeter, the time T1 from the ignition until reaching the maximum calorific value (kw / m ² ), and the maximum calorific value The ratio (T2 / T1) of time T2 until the calorific value decreased to 30% of the maximum calorific value after showing
<Evaluation of heat resistance of resin moldings>
The heat-resistant deterioration of the molded body was tested by cutting the prepared sheet into a 50 mm length and 25 mm width and hanging it on a rotating ring in a gear oven with a 50 ° C. damper opening at 50 ° C. The time until whitening due to precipitation of particles on one surface and the time until 10% of the weight was reduced were determined.
<Strength evaluation of resin molding>
About the created sheet | seat, the tension test was done based on the rubber | gum tensile characteristic of JISK6251, and the yield point, the maximum tensile strength, and elongation at break were calculated | required. The dumbbell used in the test was dumbbell-shaped No. 1 according to JISK6251.

Tables 4 to 6 show the evaluation results of the resin moldings of Examples 17 to 32 and Comparative Examples 8 to 14, respectively.

As is apparent from Tables 1 to 6, the magnesium hydroxide composition of the present invention represented by the examples is a resin composition having a good balance of hue, flame retardancy and durability, heat deterioration resistance, and strength. And a molded object can be provided.

On the other hand, as represented by a comparative example, a magnesium hydroxide composition that does not satisfy the requirements of the present invention provides a resin composition and a molded body having a good balance of hue, flame retardancy and its sustainability, and strength. I can't.
Specifically, since the magnesium hydroxide composition of Comparative Example 1 has a low content of iron and manganese, the resin composition of Comparative Example 8 using the composition shows no char formation and persistence. It is inferior in nature.

In addition, since the magnesium hydroxide composition of Comparative Example 2 has a high content of iron and manganese, the resin composition of Comparative Example 9 using the composition is inferior in the L value and b value of the hue, and also deteriorated in heat resistance. Slightly inferior in sex (time to 10% weight loss).

Further, since the magnesium hydroxide composition of Comparative Example 3 has a low sulfur content, the resin composition of Comparative Example 10 using the composition is inferior in heat resistance deterioration (time to 10% weight loss). . *

Further, since the magnesium hydroxide composition of Comparative Example 4 has a high sulfur content, the resin composition of Comparative Example 11 using the composition is inferior in heat resistance deterioration (time to 10% weight loss). The b value of the hue is slightly inferior.

In addition, since the magnesium hydroxide composition of Comparative Example 5 has a small ratio S / M, the resin composition of Comparative Example 12 using the composition has a hue b value and heat deterioration resistance (time to 10% weight loss). ).

In addition, since the magnesium hydroxide composition of Comparative Example 6 has a large ratio S / M, the resin composition of Comparative Example 13 using the composition is inferior in the L value of the hue.

In addition, since the magnesium hydroxide composition of Comparative Example 7 has a low content of iron and manganese, the resin composition of Comparative Example 14 using the composition does not show the formation of char and is also durable. Inferior.

The magnesium hydroxide composition of the present invention contains a metal element of iron and / or manganese and sulfur, so that the flame retardancy and its persistence can be achieved with a relatively small amount of blending, and without causing deterioration of physical properties. In addition to excellent heat resistance, it can impart excellent heat resistance and hue to the resin, so it is useful especially in the field of resin compositions for molded products used under severe conditions such as electric wires, cables and electronic parts. is there.

Claims (11)

1. It consists of magnesium hydroxide particles containing iron and / or manganese and sulfur, and the content M of iron and / or manganese as measured with an atomic absorption spectrophotometer is in the range of 10 to 1000 ppm with respect to the magnesium hydroxide particles. The sulfur content S measured by the absorption method is in the range of 10 to 1800 ppm with respect to the magnesium hydroxide particles, and the ratio S / M of the sulfur content S to the iron and / or manganese content M is 1.0 to A magnesium hydroxide composition having a range of 1.8.
2. The magnesium hydroxide composition according to claim 1, wherein the whiteness W is 98 or more, the L value is 78 or more, and the b value is 3.5 or less.
3. At least one surface treatment selected from fatty acids, alicyclic carboxylic acids, aromatic carboxylic acids, resin acids, their metal salts, their amine salts, their esters, surfactants, coupling agents, and phosphate esters The magnesium hydroxide composition according to claim 1 or 2, which is surface-treated with an agent.
4. 50% average particle size Dp ₅₀ measured with a laser diffraction / scattering particle size distribution meter is 0.5 to 2.0 μm, maximum particle size D _Max measured with a laser diffraction / scattering particle size distribution meter is 6.5 μm or less, nitrogen adsorption method The magnesium hydroxide composition according to any one of claims 1 to 3, wherein the BET specific surface area Sw measured in (1) is 1 to 10 m ² / g.
5. An iron chloride solution and / or a manganese chloride solution is added to magnesium hydroxide particles obtained by reacting a magnesium chloride solution containing sulfate ions with a hydroxide solution, or surface-treated magnesium hydroxide particles obtained by surface-treating the magnesium hydroxide particles. The manufacturing method of the magnesium hydroxide composition characterized by adding.
6. Magnesium hydroxide particles obtained by reacting a magnesium chloride solution and a hydroxide solution, or surface-treated magnesium hydroxide particles obtained by surface-treating it, a solution obtained by mixing an iron chloride solution and / or a manganese chloride solution and a sulfur compound. The manufacturing method of the magnesium hydroxide composition characterized by adding.
7. The amount of iron and / or manganese in the iron chloride solution and / or manganese chloride solution is 10 to 1000 ppm with respect to the magnesium hydroxide particles or the surface-treated magnesium hydroxide particles obtained by surface-treating the particles. The manufacturing method of the magnesium hydroxide composition of Claim 5 or 6.
8. The ratio Sm / Mm of the mole number Sm of sulfur in the sulfur compound to the mole number Mm of iron and / or manganese in the iron chloride solution and / or manganese chloride solution is 1.9 to 3.3, The manufacturing method of the magnesium hydroxide composition of Claim 6.
9. The method for producing a magnesium hydroxide composition according to claim 6 or 8, wherein the sulfur compound is at least one reducing agent selected from a thiosulfuric acid compound and dechlorin.
10. A resin composition comprising the resin and the magnesium hydroxide composition according to any one of claims 1 to 4.
11. A molded product obtained by molding the resin composition according to claim 10.