KR102384088B1 - Heat-resistant aluminum hydroxide and method for producing same - Google Patents

Abstract

The present invention relates to heat-resistant aluminum hydroxide containing 100 parts by mass of aluminum hydroxide powder having a boehmite precursor content of 0.1 mass% or more and 10 mass% or less, and 0.01 mass part or more and 5 mass parts or less of a fluorine atom-containing complex.

Description

Heat-resistant aluminum hydroxide and its manufacturing method {HEAT-RESISTANT ALUMINUM HYDROXIDE AND METHOD FOR PRODUCING SAME}

The present invention relates to aluminum hydroxide having heat resistance and a method for producing the same.

Gibbsite-type aluminum hydroxide is blended with various polymer materials used for electronic components such as printed wiring boards, electric wire covering materials, insulating materials, etc. using a mechanism in which water contained in crystals is dehydrated by heating. It is used as a flame retardant for imparting flame retardancy. On the other hand, as shown below, gibzite-type aluminum hydroxide starts dehydration from around 220 to 230 ° C. Depending on the type of resin, this dehydration range corresponds to the processing temperature range, so it is used as a flame retardant. There were times when it was difficult to do.

It is known that the dehydration of gibzite-type aluminum hydroxide (alumina trihydrate) generated when heated gradually in an atmospheric atmosphere originates from the following two.

(1) Al ₂ O ₃ ·3H ₂ O ⇒ Al ₂ O ₃ ·H ₂ O + 2H ₂ O

(2) Al ₂ O ₃ ·3H ₂ O ⇒ Al ₂ O ₃ + 3H ₂ O

(1) is dehydration from gibzite-type aluminum hydroxide to boehmite, which is alumina monohydrate, and (2) is dehydration to alumina. In general, dehydration in (1) occurs well from the low-temperature side (about 220°C), and (2) starts at the same time as (1) or from the high-temperature side (about 230°C). For this reason, in order to improve the heat resistance of gibzite-type aluminum hydroxide, heat treatment under various conditions is carried out, and the dehydration in (1) and (2) partially proceeds in advance, which occurs on the low temperature side. has been

For example, in Patent Document 1, aluminum hydroxide having an average particle diameter of 0.3 to 4.5 µm is partially dehydrated by heat treatment in advance, thereby representing Al ₂ O ₃ ·nH ₂ O (wherein n is the number of hydration water). It is described that aluminum hydroxide is obtained and is excellent in heat resistance.

Patent Document 2 discloses a method for producing χ-alumina by subjecting aluminum hydroxide particles to heat treatment at 230 to 270°C in an atmospheric atmosphere to improve heat resistance. Moreover, in the Example of patent document 2, it is described that aluminum hydroxide was heat-processed in air atmosphere using the disk dryer at 260 degreeC for a residence time of 30 minutes.

In addition, in Patent Document 3, the production of defects on the outermost surface by heat-treating gibzite-type aluminum hydroxide produced by the Bayer method under a pressure of atmospheric pressure or more and 0.3 MPa or less and a water vapor mole fraction of 0.03 or more and 1 or less. It is described that a thermal history can be provided while suppressing, and the heat resistance of aluminum hydroxide is improved.

On the other hand, as a method of further improving heat resistance, a method using various additives has been proposed. For example, in Patent Document 4, aluminum hydroxide and a reaction retardant that retards boehmite are mixed, and by hydrothermal treatment in a pressure vessel or pressurization and heating in a steam atmosphere, an environment in which the phase transition to boehmite is completely original. , it is described that a thermal history can be imparted while suppressing boehmite formation only partially, so that the heat resistance of aluminum hydroxide is improved.

Moreover, in patent document 5, the method of heat-processing 200 degreeC - 270 degreeC in the gas atmosphere containing aluminum hydroxide particle, or processing aluminum hydroxide particle with the solution containing a fluorine ion, The hydroxyl group of particle|grains A method of performing heat treatment at 200°C to 270°C after replacing a part of the fluorine with fluorine is described. According to these methods, aluminum hydroxide which has high heat resistance which cannot be achieved only by heat processing can be obtained.

Japanese Laid-Open Patent Publication No. 2002-211918 Japanese Patent Laid-Open No. 2011-84431 International Publication No. 2014/133049 International Publication No. 2004/080897 Japanese Laid-Open Patent Publication No. 2013-10665

However, in the method of patent document 4, it was necessary to heat-process aluminum hydroxide and an additive in an expensive pressure vessel. In addition, in the method of Patent Document 5, it is necessary to heat-treat together with harmful fluorine gas or heat-treat the surface of aluminum hydroxide after treating it with harmful hydrofluoric acid. For this reason, in the conventional method, it was difficult to manufacture heat-resistant aluminum hydroxide safely and with high productivity.

In addition, since aluminum hydroxide produced by the method described in Patent Documents 4 and 5 has a very high dehydration temperature, it is suitable for engineering plastics with a very high melting point, but for general-purpose resins with relatively low melting points, such as polyethylene and polypropylene, It has excessive heat resistance. On the other hand, in the aluminum hydroxide produced by the method described in Patent Documents 1 to 3, a dehydration reaction may occur at the processing temperature for processing the general-purpose resin, and the heat resistance is not sufficient.

Then, an object of this invention is to manufacture aluminum hydroxide which has sufficient heat resistance in order to use it for general-purpose resin, and heat-resistant aluminum hydroxide safely and with high productivity.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, this inventor reached this invention, as a result of repeating examination in detail about heat-resistant aluminum hydroxide and its manufacturing method.

That is, this invention includes the following preferable aspects.

[1] Heat-resistant aluminum hydroxide comprising 100 parts by mass of aluminum hydroxide powder having a boehmite precursor content of 10 mass% or less, and 0.01 parts by mass or more and 5 parts by mass or less of a fluorine atom-containing complex.

[2] The heat-resistant aluminum hydroxide according to [1], wherein the aluminum hydroxide powder has an average particle diameter of 0.5 µm or more and 15 µm or less.

[3] The heat-resistant aluminum hydroxide according to [1] or [2], wherein the total sodium content of the aluminum hydroxide powder is 0.01 mass% or more and 0.1 mass% or less in terms of Na ₂ O.

[4] The heat-resistant aluminum hydroxide according to any one of [1] to [3], wherein the fluorine atom-containing complex is solid at 25°C and 100 kPa.

[5] The heat-resistant aluminum hydroxide according to any one of [1] to [4], wherein the central element of the fluorine atom-containing complex is boron (B), aluminum (Al), or phosphorus (P).

[6] The heat-resistant aluminum hydroxide according to any one of [1] to [5], wherein the fluorine atom-containing complex is aluminum fluoride or sodium fluoride phosphate.

[7] The heat-resistant aluminum hydroxide, wherein the time until it decreases by 1 mass% at 230°C is 5 minutes or more and 60 minutes or less.

[8] The heat-resistant aluminum hydroxide according to any one of [1] to [7], wherein the average particle diameter is 0.5 µm or more and 15 µm or less.

[9] The heat-resistant aluminum hydroxide according to any one of [1] to [8], wherein the BET specific surface area is 0.5 m 2 /g or more and 1.8 m 2 /g or less.

[10] The heat-resistant aluminum hydroxide according to any one of [1] to [9], wherein the boehmite content is 15 mass% or less.

[11] A resin composition comprising a resin and the heat-resistant aluminum hydroxide according to any one of [1] to [10].

[12] Any one of [1] to [10], comprising mixing 100 parts by mass of aluminum hydroxide powder having a boehmite precursor content of 10 mass% or less and 0.01 parts by mass or more and 5 parts by mass or less of the fluorine atom-containing complex Method for producing heat-resistant aluminum hydroxide described in.

[13] The method according to [12], which includes producing the aluminum hydroxide powder by the Bayer method.

ADVANTAGE OF THE INVENTION According to this invention, in order to use for general-purpose resin, the aluminum hydroxide which has sufficient heat resistance can be provided. Further, according to the present invention, heat-resistant aluminum hydroxide capable of withstanding the processing temperature of general-purpose resins can be safely and with high productivity, without the need for heat treatment with an additive containing harmful fluorine.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail.

The heat-resistant aluminum hydroxide of the present invention contains an aluminum hydroxide powder and a fluorine atom-containing complex. In this invention, content of the boehmite precursor of aluminum hydroxide powder is 10 mass % or less, Preferably it is 7 mass % or less, More preferably, it is 5 mass % or less, More preferably, it is 3 mass % or less. When the content of the boehmite precursor in the aluminum hydroxide powder is less than or equal to the upper limit, the heat-resistant aluminum hydroxide can exhibit more excellent heat resistance because boehmite is not easily generated when the heat-melted resin and heat-resistant aluminum hydroxide are kneaded. In addition, the lower limit of content of the boehmite precursor of aluminum hydroxide powder is 0 mass % or more normally, for example, it is 0.1 mass % or more.

The heat-resistant aluminum hydroxide of the present invention is 0.01 parts by mass or more, preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and 5 parts by mass or less, preferably 3 parts by mass with respect to 100 parts by mass of the aluminum hydroxide powder. part or less, more preferably 1 part by mass or less of the fluorine atom-containing complex. When the content of the fluorine atom-containing complex in the heat-resistant aluminum hydroxide of the present invention is equal to or greater than the lower limit, the aluminum hydroxide powder and the fluorine atom-containing complex can sufficiently contact, and the heat resistance of the heat-resistant aluminum hydroxide can be further improved. In addition, when the content of the fluorine atom-containing complex in the heat-resistant aluminum hydroxide of the present invention is below the upper limit, the content ratio of the aluminum hydroxide powder in the heat-resistant aluminum hydroxide does not decrease too much, and the heat-resistant aluminum hydroxide exhibits higher heat resistance. can

Heat-resistant aluminum hydroxide of the present invention WHEREIN: Time until the mass decreases by 1 mass % at 230 degreeC becomes like this. Preferably it is 5 minutes or more, More preferably, it is 7 minutes or more, More preferably, it is 10 minutes or more. and preferably 60 minutes or less, more preferably 30 minutes or less, and still more preferably 20 minutes or less.

The aluminum hydroxide powder can provide a flame retardance to resin by mix|blending with resin. On the other hand, when mix|blending with resin, it is necessary to knead|mix with heat-melted resin. Although the temperature of heat melting differs depending on the resin composition and compounding composition, if it is a general-purpose resin such as polypropylene or polyethylene, it is generally 230 ° C. or less, so it is preferable that the material to be blended does not decompose when kneaded at 230 ° C. . Although the melt-kneading time also varies depending on the resin composition and the compounding composition, in order to ensure the uniformity of the resin and the aluminum hydroxide powder in the resin composition, it is preferable to knead for at least 5 minutes or longer. Therefore, as for the heat-resistant aluminum hydroxide of this invention, heat-resistant aluminum hydroxide is hard to decompose|disassemble at the time of kneading|mixing with resin that time until it reduces by 1 mass % in 230 degreeC is more than the said lower limit. Further, in the heat-resistant aluminum hydroxide of the present invention, if the time until the decrease by 1 mass% at 230°C is less than or equal to the upper limit, the water release rate does not decrease in the resin composition containing the resin and heat-resistant aluminum hydroxide, the resin The composition can exhibit excellent flame retardancy.

In the present invention, the average particle diameter of the aluminum hydroxide powder contained in the heat-resistant aluminum hydroxide is preferably 0.5 µm or more, more preferably 1.0 µm or more, still more preferably 2.0 µm or more, and preferably 15.0 µm or less, More preferably, it is 10.0 micrometer or less, More preferably, it is 7.0 micrometer or less. When the average particle diameter of the aluminum hydroxide powder is less than or equal to the above upper limit, the resin composition containing the resin and heat-resistant aluminum hydroxide is particularly excellent in flame retardancy, and when used as a wire covering material or a printed wiring board, the smoothness of the surface does not decrease easily. . Moreover, when the average particle diameter of aluminum hydroxide powder is more than the said lower limit, the uniformity of aluminum hydroxide powder and a fluorine atom containing complex can be ensured, and the heat resistance of heat-resistant aluminum hydroxide can be improved further.

In the present invention, the total sodium content of the aluminum hydroxide powder is preferably 0.1 mass% or less, more preferably 0.05 mass% or less, in terms of Na ₂ O. The heat resistance of the heat-resistant aluminum hydroxide obtained as total sodium content of the aluminum hydroxide powder in this invention being below the said upper limit can be improved further. In addition, the lower limit of the total sodium content of the aluminum hydroxide powder in this invention is 0.01 mass % or more normally, for example, it is 0.03 mass % or more. The total sodium content can be measured, for example, by the spectroscopic analysis method described in JIS-R9301-3-9.

In the present invention, the BET specific surface area of the aluminum hydroxide powder contained in the heat-resistant aluminum hydroxide is preferably 0.5 m / g or more, more preferably 0.7 m / g or more, still more preferably 1.0 m / g or more, Preferably it is 8.0 m2/g or less, More preferably, it is 5.0 m2/g or less, More preferably, it is 3.0 m2/g or less. When the BET specific surface area of the aluminum hydroxide powder is equal to or less than the upper limit, the amount of adsorbed water on the surface of the aluminum hydroxide powder is suppressed, and foaming due to dehydration can be suppressed during processing and use. Moreover, the flame retardance of the resin composition containing resin and heat-resistant aluminum hydroxide that the BET specific surface area of aluminum hydroxide powder is more than the said lower limit improves further.

The aluminum hydroxide powder contained in the heat-resistant aluminum hydroxide of the present invention is a coupling agent such as a silane coupling agent and a titanate coupling agent; Aromatic carboxylic acids, such as benzoic acid, and their ester; You may surface-treat with additives, such as a silicate and silicone. The surface treatment can be performed by either dry or wet treatment methods.

As a dry surface treatment method, for example, a method of mixing aluminum hydroxide powder and an additive in a Henschel mixer or a Rodige mixer, and in order to uniformly coat the additive, a mixture of aluminum hydroxide powder and an additive is put into a grinder and pulverized how to do it, etc.

Examples of the wet surface treatment method include a method of dispersing or dissolving an additive in a solvent, dispersing aluminum hydroxide powder in the obtained solution, and drying the obtained dispersion.

It is preferable that the fluorine atom containing complex in this invention is solid at 25 degreeC and 100 kPa. When the fluorine atom-containing complex is gas or liquid at 25°C and 100 kPa, it becomes difficult to immobilize the fluorine atom-containing complex with respect to the aluminum hydroxide powder. this may be hindered.

The fluorine atom-containing complex in the present invention is, for example, represented by the general formula MF _n (wherein n represents an integer of 1 or more) by the central element (M) and fluorine (F) as a ligand. Examples of the central element M include boron (B), aluminum (Al), silicon (Si), phosphorus (P), titanium (Ti), and zirconium (Zr). The central element M is preferably boron (B), aluminum (Al), or phosphorus (P), and more preferably aluminum (Al) or phosphorus (P) from the viewpoint of safety during production or use.

Specific examples of the fluorine atom-containing complex represented by MF _n include boron fluoride (BF ₃ ), aluminum fluoride (AlF ₃ ), phosphorus fluoride (PF ₃ ), and the like.

Further, in the fluorine atom-containing complex in the present invention, H _p MF _q (wherein p and q are each independently 1 It may be an acid represented by the above integer), or may be a polymerization salt thereof or the like. As an element contained in a neutralization salt, an alkali metal and alkaline-earth metal are mentioned, for example, Lithium, sodium, potassium, magnesium, calcium, etc. are mentioned specifically,. Examples of the acid and its polymerization salt include fluoroboric acid (HBF ₄ ), lithium fluoroborate (LiBF ₄ ), sodium fluoroborate (NaBF ₄ ), aluminic acid fluoride (H ₃ AlF ₆ ), lithium aluminate fluoride ( Li ₃ AlF ₆ ), sodium fluoride aluminate (Na ₃ AlF ₆ ), fluorophosphoric acid (H ₃ PF ₆ ), lithium fluorophosphate (Li ₃ PF ₆ ), and sodium fluorophosphate (Na ₃ PF ₆ ); there is.

The fluorine atom-containing complex is more preferably aluminum fluoride or sodium fluoride phosphate having low toxicity from the viewpoint of safety during production or use.

Aluminum fluoride is solid at 25°C and 100 kPa. When using aluminum fluoride, it is preferable to grind|pulverize and use it. By grinding, the activity of aluminum fluoride can be increased, and the heat resistance of aluminum hydroxide can be further improved. The grinding method is not particularly limited, and it can be carried out by either a dry or wet treatment method.

Although a hydrate may be used as aluminum fluoride, it is preferable to use the anhydride represented by AlF ₃ . In addition, when using a hydrate as aluminum fluoride, content of the fluorine atom containing complex in heat-resistant aluminum hydroxide is converted into an anhydride, and is computed.

The average particle diameter of aluminum fluoride is preferably 0.01 µm or more, more preferably 0.05 µm or more, still more preferably 0.1 µm or more, particularly preferably 0.2 µm or more, preferably 5 µm or less, more preferably 1 μm or less, more preferably 0.8 μm or less, particularly preferably 0.5 μm or less. Aggregation of aluminum fluoride does not generate|occur|produce easily that the average particle diameter of aluminum fluoride is more than the said lower limit, and it mixes with aluminum hydroxide powder easily. Moreover, aluminum fluoride can fully contact aluminum hydroxide powder as the average particle diameter of aluminum fluoride is below the said upper limit, and heat resistance can further be improved.

The BET specific surface area of aluminum fluoride is preferably 10 m2/g or more, more preferably 20 m2/g or more, still more preferably 30 m2/g or more, still more preferably 35 m2/g or more, and preferably preferably 300 m2/g or less, more preferably 200 m2/g or less, still more preferably 100 m2/g or less, even more preferably 70 m2/g or less. If the BET specific surface area of aluminum fluoride is more than the said lower limit, aluminum fluoride can fully contact aluminum hydroxide powder, and heat resistance can be improved further. Moreover, when the BET specific surface area of aluminum fluoride is below the said upper limit, the amount of adsorbed water on the surface of aluminum fluoride is suppressed, and foaming by dehydration can be suppressed at the time of processing and use.

Sodium fluorophosphate is solid at 25 degreeC and 100 kPa. When using sodium fluorophosphate, you may grind|pulverize and use it. By pulverizing, the dispersibility of sodium fluorophosphate can be improved, and the heat resistance of aluminum hydroxide can be improved further. The grinding method is not particularly limited, and either dry or wet processing can be used. Since sodium fluorophosphate has high solubility in water and alcohols such as methanol and ethanol, dry grinding is preferable.

When sodium fluorophosphate is used in wet processing such as wet grinding and wet mixing, since solubility in water and alcohols such as methanol and ethanol is high, a part or all of sodium fluorophosphate is mixed with fluorophosphate ions. It exists as an ionized state with sodium ions. In that case, it can be recrystallized as sodium fluorophosphate by drying and removing a solvent.

The average particle diameter of sodium fluorophosphate is preferably 0.01 µm or more, more preferably 0.05 µm or more, preferably 500 µm or less, and more preferably 100 µm or less. When the average particle diameter of sodium fluorophosphate is more than the said lower limit, aggregation of sodium fluorophosphate does not generate|occur|produce easily, and it is easy to mix aluminum hydroxide powder. Moreover, sodium fluorophosphate can fully contact aluminum hydroxide powder as the average particle diameter of sodium fluorophosphate is below the said upper limit, and heat resistance can further be improved.

The BET specific surface area of sodium fluorophosphate is preferably 0.01 m/g or more, more preferably 1 m/g or more, still more preferably 10 m/g or more, still more preferably 35 m/g or more, Preferably it is 300 m 2 /g or less, more preferably 200 m 2 /g or less, still more preferably 100 m 2 /g or less, even more preferably 70 m 2 /g or less. If the BET specific surface area of sodium fluorophosphate is more than the said lower limit, sodium fluorophosphate can fully contact aluminum hydroxide powder, and heat resistance can further be improved. Moreover, when the BET specific surface area of sodium fluorophosphate is below the said upper limit, the amount of adsorbed water on the surface of sodium fluorophosphate can be suppressed, and foaming by dehydration can be suppressed at the time of processing and use.

The average particle diameter of the heat-resistant aluminum hydroxide of the present invention is preferably 0.5 µm or more, more preferably 1.0 µm or more, still more preferably 2.0 µm or more, preferably 15 µm or less, more preferably 10.0 µm or less, More preferably, it is 7.0 micrometers or less. When the average particle diameter of heat-resistant aluminum hydroxide is less than or equal to the above upper limit, the resin composition containing a resin and heat-resistant aluminum hydroxide is particularly excellent in flame retardancy, and when used for a wire covering material or a printed wiring board, the surface smoothness is not easily reduced . In addition, when the average particle diameter of the heat-resistant aluminum hydroxide is equal to or greater than the lower limit, the viscosity of the resin composition containing the resin and heat-resistant aluminum hydroxide does not become excessively high, and the uniformity of the resin and heat-resistant aluminum hydroxide in the resin composition can be ensured. and a resin composition can be appropriately prepared. In addition, in this invention, an average particle diameter is the particle size distribution measured by the laser scattering method. WHEREIN: It means the particle diameter used as 50% on a volume basis.

The heat-resistant aluminum hydroxide of the present invention has a BET specific surface area of preferably 0.5 m 2 /g or more, more preferably 0.7 m 2 /g or more, still more preferably 1.0 m 2 /g or more, and preferably 8.0 m 2 /g or less. , more preferably 3.0 m 2 /g or less, still more preferably 1.8 m 2 /g or less. When the BET specific surface area of the heat-resistant aluminum hydroxide is equal to or less than the upper limit, the amount of adsorbed water on the surface of the heat-resistant aluminum hydroxide is suppressed, and foaming due to dehydration can be suppressed during processing and use. Moreover, the flame retardance of the resin composition containing resin and heat-resistant aluminum hydroxide that the BET specific surface area of heat-resistant aluminum hydroxide is more than the said lower limit improves further.

The boehmite content of the heat-resistant aluminum hydroxide of the present invention is preferably 15 mass% or less, more preferably 11 mass% or less, still more preferably 5 mass% or less, still more preferably 1 mass% or less, particularly preferably Preferably it is 0.7 mass % or less, Very preferably, it is 0.5 mass % or less. When the boehmite content of heat-resistant aluminum hydroxide is below the said upper limit, when mix|blending with resin, the transparency peculiar to aluminum hydroxide is not impaired, and the resin composition can exhibit the outstanding flame retardance. Moreover, the lower limit of the boehmite content of heat-resistant aluminum hydroxide is 0 mass % or more normally, for example, it is 0.01 mass % or more.

The heat-resistant aluminum hydroxide of this invention can be manufactured by the method (it is also mentioned the manufacturing method of this invention) including the process of mixing aluminum hydroxide powder and a fluorine atom containing complex.

In the production method of the present invention, 100 parts by mass of aluminum hydroxide powder and 0.01 parts by mass or more, preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and 5 parts by mass or less, preferably 3 parts by mass Partial or less, more preferably 1 part by mass or less of the fluorine atom-containing complex is mixed. Moreover, in the heat-resistant aluminum hydroxide obtained as the mixing amount of a fluorine atom containing complex is more than the said lower limit, a fluorine atom containing complex and aluminum hydroxide powder can fully contact, and heat resistance can be improved further. Moreover, if the mixing amount of a fluorine atom containing complex is below the said upper limit, the content rate of the aluminum hydroxide powder in the heat-resistant aluminum hydroxide obtained does not fall too much, but heat-resistant aluminum hydroxide can exhibit still higher heat resistance.

In the production method of the present invention, the content of the boehmite precursor in the aluminum hydroxide powder is 10 mass% or less, preferably 7 mass% or less, more preferably 5 mass% or less, still more preferably 3 mass% or less. . When the content of the boehmite precursor in the aluminum hydroxide powder is less than or equal to the above upper limit, the heat-resistant aluminum hydroxide can exhibit more excellent heat resistance because boehmite is not easily generated when the heat-melted resin and the obtained heat-resistant aluminum hydroxide are kneaded. In addition, the lower limit of content of the boehmite precursor of aluminum hydroxide powder is 0.1 mass % or more normally, for example, 0.3 mass % or more.

Although the manufacturing method of aluminum hydroxide powder is not specifically limited, From a manufacturing cost viewpoint, Preferably, the manufacturing method of this invention includes manufacturing aluminum hydroxide powder by the Bayer method. The Bayer method is a method in which an aqueous sodium aluminate solution in a supersaturated state is prepared, seeds are added to the aqueous solution to precipitate the aluminum component contained in the aqueous solution, and the obtained slurry containing aluminum hydroxide is washed and dried to obtain aluminum hydroxide powder can be obtained

The content of the boehmite precursor in the aluminum hydroxide powder corresponds to the amount of defects in the particles contained in the gibzite-type aluminum hydroxide powder produced by the Bayer method. Defects in the particles contained in the gibzite-type aluminum hydroxide powder are gradually extinguished while generating boehmite by receiving heat of about 220°C in an atmospheric atmosphere. Therefore, although it is also possible to reduce the defect in a particle|grain by heat-processing beforehand, it is preferable to use the aluminum hydroxide powder with few intra-particle defects, preferably without heat-processing. Although it is so preferable that there is little content of the boehmite precursor in aluminum hydroxide powder, since advanced technique is required, the manufacturing cost of aluminum hydroxide powder increases. When too many, the effect of improving the heat resistance by the fluorine atom-containing complex to be mixed becomes small.

The aluminum hydroxide powder manufactured by the Bayer method is _{a gibzite -} type aluminum hydroxide powder, and the crystal structure is represented by the formula of Al(OH) ₃ or Al2O3*3H2O. The aluminum hydroxide powder in this invention may be the mixture which produced|generated the boehmite partly by heat-processing beforehand. In addition, aluminum hydroxide powder can also be mixed with a fluorine atom containing complex in the state of not only a powder form, but a cake containing water|moisture content, or water slurry.

When the boehmite precursor in the aluminum hydroxide powder is previously reduced by heat treatment, the atmospheric pressure or more and 0.3 MPa or less, preferably 0.2 MPa or less, a pressure of 180°C or more and 300°C or less, preferably 200°C or more 280 C or less, more preferably, heat-processing at the temperature of 220 degreeC or more and 260 degrees C or less.

The mixing method of the aluminum hydroxide powder and the fluorine atom containing complex is not specifically limited, Any processing method of dry type and wet type can be implemented.

As the dry treatment method, for example, a method of mixing in a Henschel mixer or a Rodige mixer, or a method of pulverizing a mixture of aluminum hydroxide powder and a fluorine atom-containing complex by putting it into a pulverizer for uniform mixing there is. Examples of the wet treatment method include a method of dispersing or dissolving a fluorine atom-containing complex in a liquid, spraying the obtained solution onto aluminum hydroxide powder, and drying the obtained wet cake. Although the liquid used as a dispersion medium is not specifically limited, Water which can be easily removed by drying is preferable. Further, when the fluorine atom-containing complex is soluble in the dispersion medium, the aluminum hydroxide powder can be treated uniformly using the fluorine atom-containing complex, regardless of the average particle and BET specific surface area of the fluorine atom-containing complex.

The heat-resistant aluminum hydroxide of the present invention is a coupling agent such as a silane coupling agent and a titanate coupling agent; aliphatic carboxylic acids such as oleic acid and stearic acid; Acid and their ester; You may surface-treat with additives, such as a silicate and silicone. The surface treatment can be performed by either dry or wet treatment methods.

As a dry surface treatment method, for example, a method of mixing aluminum hydroxide powder and an additive in a Henschel mixer or a Rodige mixer, and in order to uniformly coat the additive, a mixture of heat-resistant aluminum hydroxide and an additive is put into a grinder and pulverized how to do it, etc.

Examples of the wet surface treatment method include a method in which an additive is dispersed or dissolved in a solvent, heat-resistant aluminum hydroxide is dispersed in the obtained solution, and the obtained dispersion is dried.

The heat-resistant aluminum hydroxide of the present invention has high heat resistance and a small amount of adsorbed water, and is suitable as a filler for a resin, and can be used as a filler for a resin. Resin is not specifically limited, For example, Thermosetting resin, such as thermoplastic resins, such as rubber|gum, polypropylene and polyethylene, and an epoxy resin, etc. are mentioned. Since the heat-resistant aluminum hydroxide of this invention has the outstanding heat resistance in 230 degreeC, as for resin, the temperature of heat-melting is generally 230 degrees C or less, and it is preferable that it is a general-purpose thermoplastic resin. As such a general-purpose thermoplastic resin, polyolefin, such as polypropylene and polyethylene, polyamide, polystyrene, polyvinyl chloride, ABS (acrylonitrile butadiene styrene) resin, etc. are mentioned. The heat-resistant aluminum hydroxide of the present invention can be preferably used as a filler for general-purpose resins having a heat-melting temperature of generally 230°C or less.

The resin composition containing the heat-resistant aluminum hydroxide and resin of this invention can be obtained by mixing heat-resistant aluminum hydroxide and resin using a well-known method generally used.

The resin composition containing heat-resistant aluminum hydroxide and resin of the present invention is, for example, a printed wiring board or a prepreg constituting the same, in addition to members such as electronic components of electronic devices, wire covering materials, polyolefin molding materials, tires, artificial Building materials, such as marble, etc. are mentioned, Especially preferable uses are components of electronic devices, such as a printed wiring board and sealing material, which require high heat resistance at the time of processing and use, and a wire covering material.

Example

The present invention will be described in more detail below by way of Examples and Comparative Examples.

In addition, the average particle diameter, BET specific surface area, total sodium content, boehmite precursor content, and boehmite content were measured about the aluminum hydroxide powder in an Example and a comparative example according to the measuring method shown below. Moreover, an average particle diameter, BET specific surface area, boehmite content, and heat resistance were measured about the heat-resistant aluminum hydroxide in an Example and a comparative example according to the method shown below.

(1) average particle diameter

As the measuring device, a laser scattering particle size distribution measuring device (“Microtrack MT-3300 EXII” manufactured by Nikkiso Co., Ltd.) was used. After adding a sample to 0.2 mass % sodium hexametallic acid aqueous solution and adjusting to a measurable concentration, after irradiating the ultrasonic wave of output 25W for 120 second, it measured with the sample number 2, and the particle diameter and particle diameter distribution curve were calculated|required from the average value. The average particle diameter was calculated|required as 50 mass % equivalent particle diameter (D50 (micrometer)). Moreover, when the average particle diameter calculated|required by the said method showed 2 micrometers or less, the measurement condition was changed and the value measured after irradiating the ultrasonic wave of output 40W for 300 second was employ|adopted.

(2) BET specific surface area

The BET specific surface area of the sample was determined by the nitrogen adsorption method using a fully automatic specific surface area measuring device ["Macsorb HM-1201" manufactured by Mountech] in accordance with the method specified in JIS-Z-8830.

(3) total sodium content

The total sodium content contained in the sample was calculated|required in accordance with the ICP emission spectroscopy method prescribed|regulated to JIS-R9301-3-9.

(4) Boehmite precursor content

The boehmite precursor was completely crystal-transformed into boehmite by injecting 10 g of a sample into the hot-air dryer with an internal volume of 216 L and an atmospheric temperature of 220 degreeC, and heat-processing under atmospheric atmosphere and atmospheric pressure for 4 hours.

Next, Cu was used as an X-ray source, and in the powder X-ray-diffraction measuring apparatus ["RINT-2000" manufactured by Rigaku Corporation], the content of the boehmite precursor was measured under the following measurement conditions.

Step width: 0.02 deg

Scan speed: 0.04 deg/sec

Acceleration voltage: 40 kV

Acceleration current: 30mA

Comparing the measurement results under the above measurement conditions and JCPDS card 70-2038 (corresponding to Gibbite-type aluminum hydroxide), the area S (002) of the peak corresponding to the (002) plane of Gibbite-type aluminum hydroxide is calculated, Similarly, the area S (020) of the peak corresponding to the (020) plane of boehmite was calculated by comparing the measurement result with the JCPDS card 83-1505 (corresponding to boehmite). The boehmite content was computed using these two peak areas and the following formula|equation.

Boehmite content (mass %) = s (020)/[S (020) + S (002)] s x 100

The boehmite precursor content contained in the sample before heat processing was computed using the calculated|required boehmite content and the following formula|equation.

Boehmite precursor content (mass %) = ｛ (boehmite content x 78/60)/[(boehmite content x 78/60) + (100 - boehmite content)] x 100

(5) Boehmite content

Cu was used as the X-ray source, and the boehmite content of the sample was measured in a powder X-ray diffraction measuring apparatus [“RINT-2000” manufactured by Rigaku Co., Ltd.] under the following measurement conditions.

Step width: 0.02 deg

Scan speed: 0.04 deg/sec

Acceleration voltage: 40 kV

Acceleration current: 30mA

Comparing the measurement results under the above measurement conditions and JCPDS card 70-2038 (corresponding to Gibbite-type aluminum hydroxide), the area S (002) of the peak corresponding to the (002) plane of Gibbite-type aluminum hydroxide is calculated, Similarly, by comparing the measurement results with JCPDS card 83-1505 (corresponding to boehmite), the area S (020) of the peak corresponding to the (020) plane of boehmite was obtained. The boehmite content was computed using these two peak areas and the following formula|equation.

Boehmite content (mass %) = s (020)/[S (020) + S (002)] s x 100

(6) heat resistance

In a differential thermogravimetric analyzer ["Thermo Plus TG8120" manufactured by Rigaku Co., Ltd.], the measurement was performed using a sample of about 10 mg. Air having a dew point temperature of -20°C or lower was flowed at a flow rate of 100 ml/min, and the temperature was raised from room temperature to 230°C at a temperature increase rate of 10°C/min, and maintained as it was. The heat resistance was evaluated by measuring the time when the weight decreased by 1% based on the time of reaching 230°C.

Example 1

Using the aluminum hydroxide powder ["CL-303" manufactured by Sumitomo Chemical Co., Ltd.] used as a raw material in Comparative Example 4 to be described later, according to the method described in WO2014/133049 [Example 1], the aluminum hydroxide powder shown in Table 1 was produced. did 100 parts by mass of the aluminum hydroxide powder shown in Table 1, and 5 parts by mass of a 10 mass % water slurry of fine powder having a BET specific surface area of 36 m 2 /g and an average particle diameter of 0.3 µm by pulverizing aluminum fluoride [manufactured by Morita Chemical Industry Co., Ltd.] powder in a polybag It wet-shake-mixed inside, and it dried at 120 degreeC, and obtained heat-resistant aluminum hydroxide (1). Each physical property of this heat-resistant aluminum hydroxide (1) was measured according to the said measuring method. The results are shown in Table 1.

Example 2

100 parts by mass of the aluminum hydroxide powder shown in Table 1 produced in Example 1, 0.3 parts by mass of sodium fluorophosphate (manufactured by Wako Pure Chemical Industries, Ltd.) powder, and 1.5 parts by mass of pure water were mixed with wet shaking in a polybag, and the mixture was stirred at 120°C. It dried to obtain heat-resistant aluminum hydroxide (2). Each physical property of this heat-resistant aluminum hydroxide (2) was measured according to the said measuring method. The results are shown in Table 1.

Example 3

100 parts by mass of the aluminum hydroxide powder shown in Table 1 produced in Example 1, 0.3 parts by mass of sodium fluorophosphate (manufactured by Wako Pure Chemical Industries, Ltd.) powder, and methyl silicate ["MS-51" manufactured by Mitsubishi Chemical Corporation, in terms of SiO ₂ ] Silicon content 51 mass %, mass average molecular weight 500-700] 0.6 mass part and 0.9 mass part of ethanol were wet-shake-mixed in a polybag, and it dried at 120 degreeC, and obtained heat-resistant aluminum hydroxide (3). Each physical property of this heat-resistant aluminum hydroxide (3) was measured according to the said measuring method. The results are shown in Table 1.

Example 4

Heat-resistant aluminum hydroxide (4) was obtained by the method similar to Example 1 except having used the aluminum hydroxide powder ["CL-310" by Sumitomo Chemical Corporation] shown in Table 1. Each physical property of this heat-resistant aluminum hydroxide (4) was measured according to the said measuring method. The results are shown in Table 1.

Example 5

Heat-resistant aluminum hydroxide (5) was obtained by the method similar to Example 2 except having used the aluminum hydroxide powder ["CL-310" by Sumitomo Chemical Co., Ltd.] shown in Table 1. Each physical property of this heat-resistant aluminum hydroxide (5) was measured according to the said measuring method. The results are shown in Table 1.

Example 6

Heat-resistant aluminum hydroxide (6) was obtained by the method similar to Example 2 except having used the aluminum hydroxide powder ["C-301N" by Sumitomo Chemical Co., Ltd.] shown in Table 1. Each physical property of this heat-resistant aluminum hydroxide (6) was measured according to the said measuring method. The results are shown in Table 1.

Comparative Example 1

The aluminum hydroxide powder shown in Table 1 produced in Example 1 was used as aluminum hydroxide (1), and each physical property of this aluminum hydroxide (1) was measured according to the said measuring method. The results are shown in Table 1.

Comparative Example 2

The aluminum hydroxide powder ["CL-310" manufactured by Sumitomo Chemical Co., Ltd.] used as a raw material in Example 4 was used as aluminum hydroxide (2), and each physical property of this aluminum hydroxide (2) was measured according to the said measuring method. The results are shown in Table 1.

Comparative Example 3

Aluminum hydroxide powder ["C-301N" manufactured by Sumitomo Chemical Co., Ltd.] used as a raw material in Example 6 was used as aluminum hydroxide (3), and each physical property of this aluminum hydroxide (3) was measured according to the above measurement method. The results are shown in Table 1.

Comparative Example 4

Aluminum hydroxide (4) was obtained by the method similar to Example 2 except having used the aluminum hydroxide powder ["CL-303" by Sumitomo Chemical Co., Ltd.] shown in Table 1. Each physical property of this aluminum hydroxide (4) was measured according to the said measuring method. The results are shown in Table 1.

Comparative Example 5

Aluminum hydroxide powder ["CL-303" manufactured by Sumitomo Chemical Co., Ltd.] used as a raw material in Comparative Example 4 was used as aluminum hydroxide (5), and each physical property of this aluminum hydroxide (5) was measured according to the above measurement method. The results are shown in Table 1.

Comparative Example 6

Aluminum hydroxide (6) was obtained by the method similar to Example 2 except having used the aluminum hydroxide powder ["C-303" by Sumitomo Chemical Co., Ltd.] shown in Table 1. Each physical property of this aluminum hydroxide (6) was measured according to the said measuring method. The results are shown in Table 1.

Comparative Example 7

Aluminum hydroxide powder ["C-303" manufactured by Sumitomo Chemical Co., Ltd.] used as a raw material in Comparative Example 6 was used as aluminum hydroxide (7), and each physical property of this aluminum hydroxide (7) was measured according to the above measurement method. The results are shown in Table 1.

Time until heat-resistant aluminum hydroxide (1)-(6) obtained by Examples 1-6 decreased by 1 mass % in 230 degreeC was long, and heat resistance brought the result high. On the other hand, it turns out that the time until aluminum hydroxide (1)-(7) in Comparative Examples 1-7 decreases by 1 mass % in 230 degreeC is short, and heat resistance is low.

Claims (13)

Heat-resistant aluminum hydroxide containing 100 mass parts of aluminum hydroxide powder whose content of a boehmite precursor is 10 mass % or less, and 0.01 mass part or more and 5 mass parts or less of a fluorine atom containing complex. The method of claim 1,
The average particle diameter of the aluminum hydroxide powder is 0.5 µm or more and 15 µm or less. The method of claim 1,
Heat-resistant aluminum hydroxide whose total sodium content of aluminum hydroxide powder is 0.01 mass % or more and 0.1 mass % or less in conversion _of Na2O. The method of claim 1,
The fluorine atom-containing complex is heat-resistant aluminum hydroxide that is solid at 25°C and 100 kPa. The method of claim 1,
The heat-resistant aluminum hydroxide whose central element of a fluorine atom containing complex is boron (B), aluminum (Al), or phosphorus (P). The method of claim 1,
The fluorine atom-containing complex is heat-resistant aluminum hydroxide, which is aluminum fluoride or sodium fluoride phosphate. The method of claim 1,
Heat-resistant aluminum hydroxide whose time until it reduces by 1 mass % in 230 degreeC is 5 minutes or more and 60 minutes or less. 8. The method of claim 1 or 7,
Heat-resistant aluminum hydroxide having an average particle diameter of 0.5 µm or more and 15 µm or less. 8. The method of claim 1 or 7,
Heat-resistant aluminum hydroxide having a BET specific surface area of 0.5 m 2 /g or more and 1.8 m 2 /g or less. 8. The method of claim 1 or 7,
Heat-resistant aluminum hydroxide whose boehmite content is 15 mass % or less. A resin composition comprising a resin and the heat-resistant aluminum hydroxide according to claim 1 or 7. The heat-resistant aluminum hydroxide according to claim 1 or 7, comprising mixing 100 parts by mass of aluminum hydroxide powder having a boehmite precursor content of 10% by mass or less, and 0.01 parts by mass or more and 5 parts by mass or less of a fluorine atom-containing complex, How to manufacture. 13. The method of claim 12,
A method comprising producing aluminum hydroxide powder by the Bayer method.