JP6501570B2 - Filler comprising aluminum phosphate composition fixed or coated with inorganic compound, method for producing the same, and thermally conductive composition containing the filler - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a filler or the like comprising a phosphate composition of aluminum in which elution of phosphorus and aluminum is suppressed and which has excellent thermal conductivity, and in particular, an inorganic compound is fixed or coated on all or part of the surface. The present invention relates to a filler comprising a phosphate composition of aluminum, a method for producing the same, and a thermally conductive composition containing the filler.

  Since the integration density of heat-generating components such as semiconductor devices has increased along with the reduction in size, weight, speed and multifunctionality of information processing equipment and precision machinery, heat dissipation characteristics are ensured so that heat is not accumulated in these equipment. A thermally conductive resin composition (also referred to as a heat dissipating resin composition) is being developed.

  As described in, for example, JP-A-2005-330426 (Patent Document 1), the heat conductive resin composition is a metal powder, a metal oxide powder, a ceramic powder, in order to obtain excellent heat dissipation characteristics. Specifically, aluminum powder, copper powder, silver powder, nickel powder, gold powder, aluminum oxide powder, zinc oxide powder, magnesium oxide powder, aluminum nitride powder, boron nitride powder, silicon nitride powder, diamond powder, carbon powder, silica It manufactures by using the particle | grains which consist of inorganic materials which have thermal conductivity, such as a powder, as a thermally conductive filler (heat dissipation filler), and mixing in resin.

  However, the production cost of nitride is extremely high, alumina is high in hardness and there is a problem in workability, magnesium oxide is in a problem of water resistance, silica is not good in thermal conductivity and inferior in workability. For example, the above-mentioned thermally conductive filler did not satisfy all of the thermal conductivity, the processability, the water resistance, the flame retardancy and the production cost.

  For this reason, the applicant exhibits excellent thermal conductivity, insulation, low specific gravity, low polishability and the like, and since it is relatively easy to manufacture and inexpensive to manufacture, Japanese Patent Application No. 2014-26252 (Patent Document 2) A thermally conductive filler was developed consisting of particles of a phosphate composition of aluminum, as described in U.S. Pat.

  However, high quality such as environmental stability is also required of the heat-releasing resin composition in which the heat conductive filler is used, and in particular, it is required to have high heat resistance / moisture resistance. In fact, it is required that the heat-dissipating resin composition does not deteriorate even when exposed to an atmosphere of temperature 120 ° C./humidity 100%, for example. For this reason, in the case of a thermally conductive filler comprising particles of the above-mentioned aluminum phosphate composition, in particular, phosphorus (P) in the filler elutes into the heat-dissipating resin composition, resulting in a molded body. There is a problem that it degrades to reduce its strength and the like.

JP 2005-330426 A Japanese Patent Application No. 2014-26252

  Therefore, in the present invention, a filler comprising a phosphate composition of aluminum having suppressed phosphorus elution and yet having excellent thermal conductivity, a method for producing the same, and a thermally conductive composition containing the filler are obtained. The purpose is

  The present inventors examined the factor etc. which phosphorus elutes from the filler of the phosphate composition of aluminum in the case of being exposed under high temperature and high humidity atmosphere, etc., and the improvement and modification method of the phosphate composition of aluminum As a result of repeated investigations, etc., it was found that the elution of phosphorus and aluminum can be effectively suppressed by surface-treating a filler consisting of a phosphate composition of aluminum with an inorganic compound, and the present invention has been completed. .

  That is, the filler of the aluminum phosphate composition of the present invention is characterized in that the inorganic compound adheres to all or part of the surface, or all or part of the surface is coated with the inorganic compound. have.

  As an inorganic compound used as a fixing or covering material, carbonates, hydroxides or oxides consisting of alkaline earth metals such as calcium, or carbonates or hydroxides of amphoteric metals such as magnesium, aluminum, zinc or the like An oxide is preferred, and more specifically, magnesium hydroxide, calcium carbonate or basic zinc carbonate and the like can be mentioned.

  According to the present invention, a filler comprising a phosphate composition of aluminum is coated with an inorganic compound comprising a carbonate or hydroxide such as calcium, magnesium, aluminum or zinc, or an oxide, or the above inorganic compound The elution of phosphorus and aluminum can be suppressed to a negligible extent regardless of the range in which the inorganic compound is attached or coated on the surface of the filler. In addition, even if the inorganic compound is fixed or coated, the characteristics such as the excellent thermal conductivity, the insulating property, the low specific gravity, and the low abrasiveness originally possessed by the filler composed of the aluminum phosphate composition are impaired. There is nothing to be done.

  In addition, an inorganic compound such as magnesium hydroxide, calcium carbonate or basic zinc carbonate is contained in an amount of 1.0% by weight or more in the aluminum phosphate composition (filler) as the fixed amount or the covering amount thereof. Is more preferable, and 10.0% by weight or less is more preferably contained in the composition.

  When the above-mentioned inorganic compound is contained in the phosphate composition of aluminum as 1.0% by weight or more as the fixed amount or the coated amount, the elution amount of phosphorus does not adhere to or cover the inorganic compound. It is reduced to a few tenths to a few hundredths as compared with. Moreover, the elution amount suppression effect of phosphorus by carrying out the surface treatment of the phosphate composition of aluminum with an inorganic compound is that the adhering amount or covering amount of the inorganic compound in the phosphate composition of aluminum is 1.0 weight% Even if it increases, it becomes almost unchanged.

  In addition, when the above-mentioned inorganic compound is contained in the phosphate composition of aluminum in an amount of 3.0% by weight or more as the adhering amount or the covering amount, the elution amount of aluminum is suppressed to 0 ppm.

  Furthermore, a filler consisting of the aluminum phosphate composition of the present invention having an inorganic compound fixed or coated thereon has an excellent thermal conductivity of 2.0 W / m · K or more even when dispersed in a predetermined resin. Indicates the rate. In particular, the thermal conductivity described above has the highest value (peak value) when the amount of adhesion or coverage of the inorganic compound to the phosphate composition of aluminum is in the range of 1.0% by weight or more and 10.0% by weight or less. Indicates

  In the present invention, the aluminum phosphate composition is preferably adjusted to have an Al: P atomic ratio in the range of 1: 0.8 to 1: 3.2, preferably 1: 1 to 1: 3. More preferably, it is adjusted within the range of

  The atomic ratio of Al: P in the phosphate composition of aluminum is preferably adjusted in the range of 1: 0.8 to 1: 3.2, more preferably in the range of 1: 1 to 1: 3. Thus, a filler composed of a phosphate composition of aluminum can exhibit particularly excellent thermal conductivity, insulation, low density, and low polishability.

  Thus, the aluminum phosphate composition in which the atomic ratio of Al: P is adjusted within a specific range includes phosphorus of various aluminums such as aluminum tripolyphosphate, aluminum pyrophosphate, aluminum metaphosphate and aluminum orthophosphate. Contains acid salts. Among them, since aluminum metaphosphate, aluminum orthophosphate or a mixture thereof has excellent thermal conductivity, it is suitable as a material for producing the filler of the present invention in which elution of phosphorus and aluminum is suppressed.

Furthermore, the filler of the present invention, which is surface-treated with an inorganic compound, has a spherical shape because it exhibits excellent dispersibility when blended into a composition such as a resin material, an oil agent, or a grease as it has a roundness. Is preferred. In this case, the aspect ratio of the particles comprising the phosphate composition of aluminum before surface treatment with the inorganic compound is 1.0 to 1.2 and / or the specific surface area according to the BET method is 1.5 m ² / g or less Moreover, it is preferable that an aspect ratio exists in the range of 1.0-1.2 as another parameter | index which shows that the filler of this invention surface-treated by the inorganic compound is roundish.

In general, the density of alumina used as a thermally conductive filler is about 3.9 g / cm ³ . On the other hand, the density of the filler of the present invention surface-treated with an inorganic compound is about 2.6 g / cm ³ . For this reason, since the filler of the present invention has a specific gravity smaller than that of aluminum oxide, when it is filled with the same volume ratio as that of alumina in the thermally conductive composition as a thermally conductive filler, the total weight in the composition after filling Can be reduced. Therefore, the filler of the present invention, when used as a thermally conductive filler, greatly contributes to weight reduction of the final product and high filling of the filler per unit weight.

  The filler of the present invention surface-treated with an inorganic compound preferably has an average particle diameter of 1 to 100 μm, more preferably 5 to 70 μm, and 10 to 50 μm More preferably, it has an average particle size.

  When the average particle size of the filler consisting of the phosphate composition of aluminum fixed or coated with an inorganic compound is smaller than 1 μm, the filler becomes strongly coagulated, and the composition such as resin, paint, oil, grease etc. It can not be blended uniformly or in high concentration. On the other hand, when the average particle size is larger than 100 μm, the filler density in the composition such as resin, paint, oil, grease and the like can not be increased.

  A filler comprising the phosphate composition of aluminum of the present invention to which an inorganic compound is fixed or coated, is incorporated as a thermally conductive filler into a resin, a paint, an oil agent, a grease or the like to obtain a thermally conductive resin composition , Various kinds of heat conductive compositions such as a heat conductive paint composition, a heat conductive oil agent composition, a heat conductive grease composition, etc. can be obtained, and the obtained heat conductive composition has excellent heat conductivity. Indicates the conductivity. In addition, additives such as a curing accelerator, a catalyst, a vulcanizing agent, a lubricant / releasing agent, a stabilizer, a light stabilizer, a coloring agent, a flame retardant, a coupling agent and the like are optionally added to the thermally conductive composition. It can also be blended.

  For example, the filler of the present invention can be blended with a base material such as epoxy resin, silicone resin, polyamide resin, polycarbonate resin, silicone rubber, polystyrene rubber, etc. as a thermally conductive filler and then dispersed to obtain excellent thermal conductivity. The heat conductive resin composition which has it can be obtained. For example, a thermally conductive resin composition prepared by blending 40 vol% or more of the filler of the present invention in a matrix made of polyethylene resin or epoxy resin is 1.0 W / m · K or more, more preferably 2.0 W A thermally conductive resin composition having a high thermal conductivity of at least / m · K can be obtained.

  Moreover, since the filler of the present invention has a so-called hardness lower than that of alumina, when it is added to a resin composition as a thermally conductive filler and a thermally conductive composition or the like is produced, processing by grinding becomes easy. , It becomes easy to apply to precision machine equipment etc. In addition to the resin, when mixed with a composition such as paint, oil, grease, etc., the abrasion of the kneader is suppressed, the material of the kneader is not mixed, and maintenance of the kneader becomes easy. There is. The abrasiveness of the aluminum phosphate composition on which the inorganic compound constituting the filler of the present invention is adhered or coated is 1/2 or less of the abrasiveness of alumina.

  A filler consisting of the aluminum phosphate composition of the present invention to which an inorganic compound is fixed or coated can be produced by a production method including the following steps (steps).

In the filler of the present invention, first, aluminum hydroxide and phosphoric acid adjusted to have an atomic ratio of Al: P of 1: 0.8 to 1: 3.2 are placed in a container such as ceramics. The mixture is heated to dissolution with stirring and mixing, and then the mixture of the heated and dissolved aluminum hydroxide and phosphoric acid is roasted at a temperature of 300.degree. C. or higher, and the roasted product is crushed to thereby obtain a BET specific surface area. It is possible to obtain a rounded spherical filler having a size of 0.1 m ² / g to 2.0 m ² / g and / or an aspect ratio of 1.0 to 1.2.

In the above-mentioned roasting step, after primary roasting at a temperature of 300 to 500 ° C., the mixture obtained by grinding, classification and classification is further 900 to 1300 ° C., more preferably 1000 to 1200 ° C. When subjected to secondary roasting at a temperature, a rounded spherical filler having a BET specific surface area of 0.1 m ² / g or more and 2.0 m ² / g or less and / or an aspect ratio of 1.0 or more and 1.2 or less It will be easier to obtain.

If the secondary roasting temperature is higher than 1300 ° C., the BET specific surface area is 0.1 m ² / g or more and 2.0 m ² / g or less, or the aspect ratio is 1 due to the influence of melting of the aluminum phosphate composition. It becomes difficult to obtain a filler having a rounded spherical shape of 0 or more and 1.2 or less. In addition, in order to obtain the filler of a desired spherical form, it is preferable to implement primary roasting about 1 to 3 hours, and secondary roasting about 1 to 5 hours.

  Further, the filler in the spherical form which has been subjected to primary roasting or primary roasting and secondary roasting, carbonates, hydroxides or oxides of alkaline earth metals, or carbonates, hydroxides or oxides of amphoteric metals Surface treatment with the above to suppress the elution of phosphorus and aluminum, yet having excellent thermal conductivity, a filler comprising the phosphate composition of the present invention, which is adhered or coated with an inorganic compound You can get it.

  As a method of surface treatment, water-soluble metal salts such as calcium chloride, calcium nitrate, calcium sulfate, magnesium chloride, magnesium nitrate, magnesium sulfate, zinc chloride, zinc nitrate, zinc sulfate, zinc-ammine complex, aluminum chloride, nitrate Dissolve aluminum in water and neutralize it with an aqueous alkaline solution such as sodium hydroxide, ammonia water, various amines, sodium carbonate, ammonium carbonate, sodium hydrogen carbonate, sodium hydrogen carbonate, etc. To process. Further, the hydroxide can be surface-treated by neutralizing an aqueous metal alkaline solution such as sodium aluminate or potassium aluminate with an acid such as sulfuric acid, hydrochloric acid or nitric acid. The oxide can be surface-treated by roasting the surface-treated aluminum phosphate composition.

  Alternatively, surface treatment can also be carried out by causing fine particles of an inorganic compound to be surface treated to be supported by mechanochemicals on core particles and the like. Further, the method of surface treatment usable in the present invention is not limited to these, and any known surface treatment can be used as long as fine particles of an inorganic compound to be surface treated can be fixed to core particles and the like. The method can be used.

  According to the present invention, there is provided a filler of spherical form consisting of a phosphate composition of aluminum fixed or coated with an inorganic compound, in which elution of phosphorus and aluminum is sufficiently suppressed. In addition, the filler of the present invention exhibits excellent thermal conductivity, insulation, low specific gravity, low polishability, and can be manufactured inexpensively by a relatively simple manufacturing method. Furthermore, the thermally conductive composition which expresses high thermal conductivity can be produced by mix | blending the filler of this invention with resin, a coating material, an oil agent, grease etc. as a thermally conductive filler by predetermined amounts.

  Further, according to the production method of the present invention, the aluminum compound and the phosphoric acid compound are mixed so that the atomic ratio of Al: P is in a specific range, roasted in a specific temperature range, and the surface with the inorganic compound. By the treatment, it is possible to easily obtain a filler of spherical form consisting of a phosphate composition of aluminum fixed or coated with an inorganic compound.

It is a SEM photograph of the filler (raw material) which consists of a phosphate composition of aluminum which is not surface-treated with an inorganic compound. It is a SEM photograph of the filler which consists of a phosphate composition of aluminum which surface-treated with magnesium hydroxide concerning one embodiment of the present invention. The moisture heat resistance test shows the relationship with the elution amount of phosphorus when the amount of fixed or coating amount of the inorganic compound is changed. The heat conductivity of the resin composition at the time of changing the adhering amount or the covering amount of the inorganic compound of the filler mix | blended with resin to 0 to 75% is shown.

  Hereinafter, a filler consisting of a phosphate composition of aluminum according to an embodiment of the present invention in which an inorganic compound is fixed or coated on all or part of the surface, a method for producing the same, and a thermally conductive composition containing the filler The objects will be described in detail with specific examples. In addition, this invention is not limited to embodiment shown below, A various change is possible within the range which does not deviate from the technical idea of this invention.

1. Preparation of Raw Materials While stirring a material (Al / P atomic ratio = 1/3) containing 3,900 g of aluminum hydroxide and 17,250 g of 85% phosphoric acid until the contents are dissolved in a ceramic container Heat on a hot plate. The solution is subjected to primary roasting and coarse crushing at 400 ° C. for 2 hours. The product is pulverized and classified with a fluid mill (manufactured by Pacific Kiko Co., Ltd., Multinojet mill MJ2070-M type) with a built-in classifier, and particles of 100 μm or more are further cut with a sieve (140 mesh). By subsequent roasting, a filler consisting of a phosphate composition of aluminum was obtained. The main component of the obtained aluminum phosphate is aluminum metaphosphate, and when the particle shape is confirmed by a scanning electron microscope, it has a round spherical shape as shown in FIG. The aspect ratio was 1.12, and the specific surface area according to the BET method was 0.5 m ² / g.

2. Preparation of Fillers of Examples 1 to 3 and Comparative Examples 1 and 2 by Surface Treatment of Raw Materials [Example 1]
Slurry 3,000 g of aluminum phosphate prepared in the above-mentioned "1. Preparation of raw materials" with 15 L of water. To the slurried aluminum phosphate, 1.5 L (530 g of magnesium chloride hexahydrate) of 350 g / L of an aqueous solution of magnesium chloride is added, and a 24 wt% aqueous solution of sodium hydroxide is added to adjust to pH 8.5. The slurry solution adjusted to pH 8.5 is heated to 80 ° C., aged for 30 minutes, filtered and washed to remove unnecessary salts. In addition, the slurry is made again, and filtration and washing are performed. The slurry solution subjected to filtration and washing is dried at 120 ° C., and crushed with an ectomicizer to obtain the filler of Example 1 in which 5% by weight of magnesium hydroxide is fixed or coated to aluminum phosphate. The

  When the obtained filler of Example 1 surface-treated with magnesium hydroxide was observed with a scanning electron microscope, as shown in FIG. 2, magnesium hydroxide covered a part of the surface of aluminum phosphate. It was observed that the filler consisting of a phosphate composition of aluminum fixed to magnesium hydroxide fixed thereto has a rounded spherical morphology as a whole.

Example 2
Slurry 3,000 g of aluminum phosphate prepared in the above-mentioned "1. Preparation of raw materials" with 15 L of water. 0.48 L of calcium chloride aqueous solution of 350 g / L (167 g of calcium chloride) is added to the slurried aluminum phosphate, and 100 g / L of sodium carbonate aqueous solution is added to adjust to pH 8.5. The slurry solution adjusted to pH 8.5 is heated to 80 ° C., aged for 30 minutes, filtered and washed to remove unnecessary salts. In addition, the slurry is made again, and filtration and washing are performed. The slurry solution subjected to filtration and washing was dried at 120 ° C., and ground with an ectomizer to obtain the filler of Example 2 in which 5% by weight of calcium carbonate was adhered to or coated with aluminum phosphate. .

[Example 3]
Slurry 3,000 g of aluminum phosphate prepared in the above-mentioned "1. Preparation of raw materials" with 15 L of water. To the slurried aluminum phosphate, 1 L (205 g of zinc chloride) of a 200 g / L aqueous solution of zinc chloride is added, and a 100 g / L aqueous solution of sodium carbonate is added to adjust to pH 8.5. The slurry solution adjusted to pH 8.5 is heated to 80 ° C., aged for 30 minutes, filtered and washed to remove unnecessary salts. In addition, the slurry is made again, and filtration and washing are performed. The slurry solution subjected to filtration and washing is dried at 120 ° C., and crushed with an ectomicizer, whereby the filler of Example 3 in which 5% by weight of basic zinc carbonate is adhered to or coated with aluminum phosphate is obtained. Obtained.

Comparative Example 1
The aluminum phosphate produced in the above-mentioned "1. Production of raw material" was used as a filler of Comparative Example 1.

Comparative Example 2
Slurry 3,000 g of aluminum phosphate prepared in the above-mentioned "1. Preparation of raw materials" with 15 L of water. To the slurryed aluminum phosphate, a 24 wt% aqueous sodium hydroxide solution is added to adjust to pH 8.5. The slurry solution adjusted to pH 8.5 is heated to 80 ° C., aged for 30 minutes, filtered and washed to remove unnecessary salts. The slurry solution subjected to filtration and washing was dried at 120 ° C., and pulverized with an ectomizer to obtain a filler of Comparative Example 2 in which aluminum phosphate was washed with water.

3. Properties of Fillers of Examples 1 to 3 and Comparative Examples 1 and 2 The aspect ratio and particle diameter of the filler composed of the phosphate composition of aluminum obtained by Examples 1 to 3 and Comparative Examples 1 and 2 are the following methods. It measured by.

(1) Aspect Ratio The aspect ratio was obtained by photographing the powder with a scanning electron microscope and measuring the length of the vertical and horizontal axes of each particle by 500 samples or more to calculate the aspect ratio of each particle.

(2) Particle Size The particle size was measured by a laser diffraction / scattering method using MICROTRAC MT 3000 manufactured by Nikkiso Co., Ltd.

  The results of measurement of the aspect ratio, particle size and Al / P atomic ratio of the filler comprising the aluminum phosphate composition obtained in Examples 1 to 3 and Comparative Examples 1 and 2 are shown in Table 1.

  The filler comprising the phosphate composition of aluminum, to which the inorganic compound of the present invention is fixed or coated, is adjusted so that the atomic ratio of Al: P is 1: 0.8 to 1: 3.2. Is preferred. If the atomic ratio of P to Al is smaller than the above range, it becomes difficult to heat and dissolve aluminum hydroxide in phosphoric acid, while if the atomic ratio of P to Al is larger than the above range, the desired Al It is not possible to obtain a phosphate composition of aluminum having an atomic ratio of P: P.

4. Moisture and Heat Resistance Test of Fillers of Examples 1 to 3 and Comparative Examples 1 and 2 The fillers of Examples 1 to 3 and Comparative Examples 1 and 2 are allowed to stand still in a thermostatic humidifier with a temperature of 100 ° C. and a humidity of 100%. After 0 hours, 250 hours and 700 hours, the fillers of Examples 1 to 3 and Comparative Examples 1 and 2 are taken out. 10 g of the fillers of Examples 1 to 3 and Comparative Examples 1 and 2 taken out are slurried in 100 mL of ion exchanged water, and boiled for 5 minutes. After cooling, the concentration of the slurry was adjusted, and after solid-liquid separation with a 0.2 μm membrane filter, the elution amounts of aluminum (Al) and phosphorus (P) in the solution were measured with an ICP emission analyzer. Moreover, the conductivity and pH of the slurry after cooling were measured.

  The measurement results of the elution amount of phosphorus and aluminum of the filler consisting of the phosphate composition of aluminum obtained in Examples 1 to 3 and Comparative Examples 1 and 2 are shown in Table 2.

  The measurement results of the pH value and the conductivity (μS / cm) of the filler comprising the aluminum phosphate composition obtained in Examples 1 to 3 and Comparative Examples 1 and 2 are shown in Table 3.

  From Tables 2 and 3, it was found that not only phosphorus but also aluminum was eluted in the case of the filler consisting of the aluminum phosphate composition of Comparative Examples 1 and 2 which was not surface-treated with an inorganic compound. . Moreover, in Comparative Examples 1 and 2, the elution of phosphorus, which causes deterioration of the resin composition, was 400 to 600 times the elution amount of phosphorus after 700 hours with respect to the elution amount of phosphorus at the beginning of the test (0 hour) It was found to increase to some extent.

  For this reason, in the case of the fillers of Comparative Examples 1 and 2, the pH value also tends to decrease as time passes. In addition, it was found that the conductivity (μS / cm) of the fillers of Comparative Examples 1 and 2 largely changed (increased by about 500 to 1000 times) as time passed, and became unstable.

  On the other hand, a filler consisting of a phosphate composition of aluminum surface-treated with magnesium hydroxide of Example 1, a filler consisting of a phosphate composition of aluminum surface-treated with calcium carbonate of Example 2 All the fillers made of the phosphate composition of aluminum surface-treated with the basic zinc carbonate of Example 3 stably suppress the elution of phosphorus and aluminum over a long period of time even under severe conditions of high temperature and humidity. It turned out to be done. For this reason, in the case of the fillers of Examples 1 to 3, the pH value and the conductivity (μS / cm) of the filler hardly change regardless of the passage of time.

  In particular, in the fillers of Examples 1 to 3, the elution of phosphorus, which causes deterioration of the resin composition, is such that the elution amount of phosphorus after 700 hours is 2 to 7 with respect to the elution amount of phosphorus at the beginning of the test (0 hour) It was found that it was suppressed almost negligible, such as being about double. For this reason, the fillers of Examples 1 to 3 which have been surface-treated with an inorganic compound have an elution amount of phosphorus several times smaller than the fillers of Comparative Examples 1 and 2 which have not been surface-treated with an inorganic compound. Can be reduced to

  FIG. 3 shows 700 hours after the adhesion amount or covering amount of magnesium hydroxide, calcium carbonate or basic zinc carbonate to aluminum phosphate of the filler is changed to 0 to 75% in the heat and humidity resistance test described above. The elution amount of phosphorus is shown.

  As will be understood with reference to FIG. 3, the filler comprising the aluminum phosphate composition surface-treated with the inorganic compound of the present invention may be magnesium hydroxide, calcium carbonate or an inorganic compound to be fixed or coated. In any case of basic zinc carbonate, the elution amount of phosphorus is surface-treated with an inorganic compound when the fixed amount or the covering amount is 1.0% by weight or more in the aluminum phosphate composition. It was found to be reduced to a few tenths to a few hundredths as compared to unfilled fillers. Moreover, the elution amount suppression effect of phosphorus by carrying out the surface treatment of the phosphate composition of aluminum with an inorganic compound is that the adhering amount or covering amount of the inorganic compound in the phosphate composition of aluminum is 1.0 weight% It has been found that even if the

5. Preparation of thermally conductive resin compositions of Examples 4 to 6 and Comparative Examples 3 and 4 [Example 4]
96 parts by weight of a polyethylene resin (Sumikasen F 705) was wound on a roll of a kneader, and 390 parts (filler content 60 volume%) of the filler of Example 1 was kneaded. The heat-conductive resin composition of Example 4 was obtained by putting the kneaded body taken out into a mold of 5 cm long x 10 cm wide x 1 mm thick and curing at a pressure of 200 kg / cm ² and 120 ° C. for 5 minutes.

[Example 5]
A thermally conductive resin composition of Example 5 was obtained under the same production conditions and production method as in Example 4 except that the filler of Example 2 was used as a filler to be blended in a polyethylene resin.

[Example 6]
A thermally conductive resin composition of Example 6 was obtained under the same production conditions and production method as in Example 4 except that the filler of Example 3 was used as a filler to be blended in a polyethylene resin.

Comparative Example 3
A thermally conductive resin composition of Comparative Example 3 was obtained under the same production conditions and method as in Example 4 except that the filler of Comparative Example 1 was used as a filler to be blended in a polyethylene resin.

Comparative Example 4
A thermally conductive resin composition of Comparative Example 4 was obtained under the same production conditions and production method as in Example 4 except that the filler of Comparative Example 2 was used as a filler to be blended in a polyethylene resin.

5. Properties of Thermally Conductive Resin Compositions of Examples 4 to 6 and Comparative Examples 3 and 4 The thermal conductivity of the thermally conductive resin compositions of Examples 4 to 6 and Comparative Examples 3 and 4 was measured by the following method.

(3) Measurement of thermal conductivity The specific heat at 25 ° C. of the obtained resin composition was measured by Hitachi High-Tech Science Co., Ltd. High sensitivity type differential scanning calorimeter DSC 7020 type, true density by Cantachrome Instruments GK Co., Ltd. Fully automatic pycnometer The thermal diffusivity was measured using an IPHASE's i-phase mobile 1u thermal diffusivity / thermal conductivity measuring apparatus using an ULTRAPYC 1200e type machine, and the thermal conductivity was calculated according to the following formula.
λ = a × ρ × Cp
[Λ: thermal conductivity (W / m · K), a: thermal diffusivity × 10 ⁻⁷ (m ² / s), :: true density (g / mL), Cp: specific heat (J / g · K) ]

  The measurement results of the thermal conductivity of the thermally conductive resin compositions of Examples 4 to 6 and Comparative Examples 3 and 4 are shown in Table 4.

  From Table 4, it was found that the thermally conductive resin compositions of Examples 4 to 6 and Comparative Examples 3 and 4 all have excellent thermal conductivity of 2.0 W / m · K or more.

  This is because the heat conductive resin compositions of Examples 4 to 6 and Comparative Examples 3 and 4 have excellent heat conductivity such that the main component of the filler compounded in each of them is aluminum metaphosphate, aluminum orthophosphate or a mixture thereof It is considered to be due to being composed of the aluminum phosphate composition having the ratio.

  FIG. 4 shows the adhesion amount or coating amount of magnesium hydroxide, calcium carbonate or basic zinc carbonate to aluminum phosphate of the filler to be added to the polyethylene resin under the same production conditions and production method as Example 4 described above. The heat conductivity of the heat conductive resin composition when changing to% is shown.

  As understood with reference to FIG. 4, the filler comprising the phosphate composition of aluminum surface-treated with the inorganic compound of the present invention, the inorganic compound to be fixed or coated is magnesium hydroxide, calcium carbonate or In any case of the basic zinc carbonate, the thermal conductivity of the thermally conductive resin composition containing the filler when the adhering amount or the covering amount is in the range of 1.0% by weight or more and 10.0% by weight or less It was found that the rate was induced to the highest value (peak value).

5. Moisture and Heat Resistance Test of Thermally Conductive Resin Composition of Examples 4 to 6 and Comparative Examples 3 and 4 A constant temperature of 100 ° C. and humidity of 100% for the thermally conductive resin compositions of Examples 4 to 6 and Comparative Examples 3 and 4 After standing for 100 hours, 200 hours, 500 hours and 1000 hours in a humidifier, the state of deterioration of the thermally conductive resin composition was visually observed and evaluated. The results are shown in Table 5.

  From Table 5, it was confirmed that the thermally conductive resin compositions of Comparative Examples 3 and 4 which have not been surface-treated with an inorganic compound deteriorate with the passage of time. This is considered that the filler of Comparative Examples 1 and 2 blended to the heat conductive resin composition of Comparative Examples 3 and 4 is due to an increase in the elution amount of phosphorus with the passage of time under high temperature and humidity conditions. .

  On the other hand, the thermally conductive resin compositions of Examples 4 to 6 which were surface-treated with an inorganic compound did not deteriorate with the passage of time. This was surface-treated with the calcium carbonate of Example 2, a filler comprising the phosphate composition of aluminum surface-treated with magnesium hydroxide of Example 1 blended into the thermally conductive resin compositions of Examples 4 to 6 The filler consisting of the phosphate composition of aluminum and the filler consisting of the phosphate composition of aluminum surface-treated with the basic zinc carbonate of Example 3 both cause elution of phosphorus under severe conditions of high temperature and humidity. Is considered to have been suppressed.

Claims (10)

A filler consisting of a phosphate composition of aluminum, in which an inorganic compound of magnesium hydroxide, calcium carbonate or zinc carbonate is fixed or coated on all or part of the surface. The filler according to any one of claims 1 to 10 , wherein the inorganic compound is contained in an amount of 1.0% by weight or more based on the aluminum phosphate composition. The filler according to claim 1 or 2 , wherein the inorganic compound is contained in an amount of 10.0% by weight or less based on the aluminum phosphate composition. The filler according to any one of claims 1 to 3 , wherein the atomic ratio of Al: P in the aluminum phosphate composition is 1: 0.8 to 1: 3.2. The filler according to claim 4 , wherein the aluminum phosphate composition is aluminum metaphosphate, aluminum orthophosphate or a mixture thereof. The filler according to any one of claims 1 to 5 , which has a spherical form with an aspect ratio of 1.0 to 1.2. The filler according to any one of claims 1 to 6 , which has an average particle size of 1 to 100 m. A thermally conductive composition in which the filler according to any one of claims 1 to 7 is dispersed in an amount of 40% by volume or more. The heat conductive composition according to claim 8 , having a thermal conductivity of 1.0 W / m · K or more. Preparing a mixture of an aluminum compound and a phosphoric acid compound adjusted to have an atomic ratio of Al: P of 1: 0.8 to 1: 3.2;
Heating and melting the mixture;
Primary roasting the heated and melted mixture at a temperature of 300-500 ° C .;
Pulverizing and classifying said primary roasted mixture;
Secondary roasting the ground and classified mixture at a temperature of 900-1300 ° C., and the secondary roasted mixture is alkaline earth metal carbonate, hydroxide or oxide, or amphoteric metal Surface treatment with carbonates, hydroxides or oxides of
The method for producing a filler according to any one of claims 1 to 7 , further comprising