JP2509214B2 - Inorganic filler - Google Patents

Description

TECHNICAL FIELD The present invention relates to an inorganic filler composed of inert spherical particles of aluminosilicate.

(Prior Art) As a filler for various polymer films and other resins and rubbers, and a filler for cosmetics, an inorganic filler having a constant particle shape and less secondary aggregation is required.

Zeolite has a constant particle shape, and is known to give anti-blocking when blended with a resin. For example, Japanese Patent Publication No. 52-16134 discloses a zeolite having an average particle diameter of 20 microns or less with respect to polypropylene. It has been shown that the addition of 0.01 to 5% by weight of powder improves the blocking resistance of the biaxially stretched film.

Further, Japanese Patent Publication No. 61-36866 discloses a cubic primary particle having a composition in which a molar ratio of Al ₂ O ₃ : SiO ₂ is in the range of 1: 1.8 to 1: 5 and having a side length of 5 μm or less. And an alumina-silica resin compounding agent which is substantially amorphous in X-ray diffraction and has a BET specific surface area of 100 m ² / g or less.

(Problems to be Solved by the Invention) However, the zeolite adsorbs water called zeolitic water, and when it is mixed with a resin or the like and heated, it tends to release the water and foam. Therefore, an aluminosilicate compounding agent which is inert and has low adsorption performance is desired.

The amorphous aluminosilicate-based resin compounding agent described above is
Since the basic component of zeolite is removed, there is little coloring tendency of the resin molded product, and compared with zeolite, it has the advantage that the surface activity and adsorptivity are suppressed to low values, but the particle shape is There is still room for improvement in that the particles are cubic and the primary particles have some tendency to aggregate.

Therefore, an object of the present invention is to provide an aluminosilicate-based inorganic filler having a remarkably low surface activity and adsorptivity, a spherical particle shape, and a small tendency of secondary aggregation.

(Means for Solving the Problem) The present inventors have confirmed that a spherical zeolite such as a P-type zeolite converted to an amorphous aluminosilicate by acid treatment and / or heat treatment was suppressed to a significantly low value. It has been found that it can be a stabilized filler having surface activity and adsorption performance, substantially spherical, and less secondary aggregation.

That is, according to the present invention, an aluminosilicate obtained by acid treatment and / or heat treatment of spherical zeolite and having a SiO ₂ content of 50% by weight or more based on the anhydride is used, and the aluminosilicate is X-ray diffraction Is substantially amorphous, the aluminosilicate has a BET specific surface area of 50 m ² / g or less and RH 90%, hygroscopicity of 13% or less at room temperature and 24 hours, the aluminosilicate is 0.2 to An inorganic filler consisting of spherical particles having an electron microscopy primary particle size of 30 μm is provided.

(Operation) According to the present invention, when spherical zeolite is made amorphous by acid treatment and / or heat treatment, a spherical filler having stable low surface activity and low adsorptivity and having a small tendency of secondary aggregation is obtained. It is based on the finding that it can be obtained.

It has been found that spherical zeolites such as P-type zeolite behaves significantly differently during heat treatment from cubic zeolites such as A-type, X-type pressed and Y-type. When A-type, X-type and Y-type zeolite is calcined at high temperature, it transforms to a crystalline form such as carnegie stone and nepheline at a certain temperature (eg 900 ° C) or higher, but at the temperatures up to that point, the original crystalline form ( A-type, X-type, and Y-type) are stable, and zeolitic water is removed with firing, but if this is left in the atmosphere,
It is recognized that the original state of the adsorbed water is restored again. On the other hand, when the P-type zeolite is subjected to a firing treatment,
At 900 ° C or higher, crystal transition to nepheline occurs, but at about 500 ° C, which is lower than that, amorphization of P-type zeolite occurs, and an amorphous state is stable between these two temperatures. To do. Moreover, the amorphized product at a temperature of 700 ° C. or higher does not return to the P-type zeolite even if the product is left to cool to room temperature and left in the atmosphere,
The amorphous state is stably maintained, and the surface activity and the adsorptivity are stably maintained in a low state without returning to the original state.

The inorganic filler in the present invention is characterized in that it is amorphized only by heat treatment of P-type zeolite and is stabilized against adsorption-desorption phenomenon. However, in some cases, it is preferable to carry out the amorphization of the P-type zeolite by a combination of heat treatment and heat treatment. That is, by treating the P-type zeolite with an acid, it is possible to remove at least a part of the alkali metal content (soda content) or even a part of the alumina content in the P-type zeolite, whereby the final inorganic filler of It is possible to reduce the alkalinity and adjust the pH of the filler (suspension pH) to an arbitrary range. Moreover, it is extremely significant that when the P-type zeolite is subjected to the acid treatment and then the heat treatment, the heat treatment temperature required for amorphization is higher than that in the case where the P-type zeolite not treated with the acid is heat treated. Can be significantly reduced, the heat treatment conditions can be relaxed, and the cost can be reduced.

Figure 1 of the accompanying drawings is an X-ray diffraction diagram of an aluminosilicate filler amorphized by firing P-type zeolite at a temperature of 700 ° C, and Fig. 2 is an X-ray diffraction diagram of the raw material P-type zeolite. Fig. 3 shows 90% P-type zeolite.
FIG. 3 is an X-ray diffraction diagram of a nepheline-type aluminosilicate obtained by firing at a temperature of 0 ° C. In addition, FIG. 4 shows that X of the aluminosilicate filler amorphized by acid treatment so as to remove 50% of the soda component (Na ₂ O) in P-type zeolite, and then by heat treatment at a temperature of 300 ° C. It is a line diffraction diagram. It will be understood from these X-ray diffraction images that the P-type zeolite is amorphized by heat treatment or a combination of acid treatment and heat treatment.

Further, FIG. 5 of the accompanying drawings is an electron micrograph (magnification: 10,000 times, the same applies hereinafter) of the aluminosilicate filler (amorphized by heat treatment) shown in FIG.
The figure is an electron micrograph of the raw material P-type zeolite (Fig. 2), and Fig. 7 is the aluminosilicate filler shown in Fig. 4 (amorphized by acid treatment-heat treatment).
It is an electron micrograph of. From these electron micrographs, it is clear that the aluminosilicate filler of the present invention has a substantially spherical particle shape and is less in secondary aggregation, like the P-type zeolite as the raw material. Also,
Careful observation of these photographs reveals that the particle size of the amorphized zeolite is smaller than that of the starting P-type zeolite.

The aluminosilicate of the invention has a SiO ₂ content of 50% by weight or more, especially 60% by weight or more, based on the anhydride.
In the untreated acid, naturally, the molar ratio of SiO ₂ : Al ₂ O ₃ and SiO ₂ : Na ₂ O is the same as that of the raw material P-type zeolite, but in the acid treated one, Al ₂ O 3 The amounts of ₃ and Na ₂ O have decreased correspondingly. A suitable composition is shown below.

110 ° C. dried product oxide basis _{SiO 2 50~80% 60~90% Al 2} O 3 5~25% 6~30% Na 2 O 0.1~15% 0.1~20% soaking loss 5-20% - present invention The aluminosilicate filler is characterized by having a low surface activity and adsorptivity due to the amorphous treatment, and generally has a BET specific surface area of 50 m ² / g or less, especially 30 m 2.
^{It has} a BET specific surface area of ² / g or less and a hygroscopicity of 13% or less, especially 7% or less under the conditions of RH 90%, room temperature and 24 hours. Due to this feature, when the filler of the present invention is blended with the polymer and thermoformed, the tendency of releasing the adsorbed moisture to cause foaming of the polymer is effectively eliminated.

The aluminosilicate-based filler of the present invention generally has a primary particle size (particle size by electron microscope photography) of 0.2 to 30 μm, particularly 0.5 to 20 μm. In the aluminosilicate-based filler of the present invention, the individual particles have a definite shape, the secondary agglomeration tendency is small, and a desired primary particle size can be obtained. For use as a stretched film filler, it is generally preferred to have a particle size of 0.3 to 3 μm. In the case of the polymer filler, a filler having a sharp particle size distribution, for example, a filler having a standard deviation (σ) of 0.8 or less can be used. In other applications, for example, in the case of a filler for cosmetics, it can be used by broadening the particle size distribution.

The aluminosilicate fillers of the present invention generally have a refractive index of 1.40 to 1.55, especially 1.45 to 1.53. Amorphous aluminosilicate produced by heat treatment has a relatively large refractive index, within the range of 1.48 to 1.55, and acid treatment-amorphous aluminosilicate produced by heat treatment has a relatively small refractive index of 1.40 to 1.50. It is within the range. Thus, according to the present invention, it will be understood that the refractive index of the filler can be easily adjusted so that sufficient transparency can be obtained when the resin molded product such as a film is obtained.

The spherical P-type zeolite particles used as a raw material are of course known per se, but in the conventional synthesis method, P-type zeolite is mixed during the synthesis of X-type zeolite and Y-type zeolite. It has not been known yet to synthesize all of them in a spherical form with good dispersion.

The present inventors have determined that sodium silicate or activated silicate gel, sodium aluminate and sodium hydroxide are in the following condition component ratio molar ratio suitable molar ratio Na ₂ O / SiO ₂ 0.2 to 8 0.5 to 2.0 SiO ₂ / Al ₂ O ₃ 3 to 20 4 to 10 H ₂ O / Na ₂ O 20 to 200 30 to 100 are mixed so as to form an alkali aluminosilicate gel, and this gel is homogenized and then 85 to 200 ° C.
The P-type zeolite is synthesized by crystallizing at a temperature of 1, 2, or under atmospheric pressure or hydrothermal conditions.

The raw material P-type zeolite preferably has the following composition.

P-type zeolite SiO ₂ 40 to 70 wt% Al ₂ O ₃ 15 to 30 wt% Na ₂ O 8 to 20 wt% H ₂ O 0 to 20 wt% From the above chemical composition, the raw material zeolite used in the present invention is SiO ₂ It can be seen that the / Al ₂ O ₃ ratio is high.

When P-type zeolite is amorphized only by heat treatment, the temperature is generally 500 to 900 ° C, especially 650 to 800 ° C.
The P-type zeolite is calcined at the temperature. Although the firing time depends on the temperature, it is set within a range of 0.5 to 5 hours, which is sufficient for amorphization.

In the case of the combination of the acid treatment and the heat treatment, at least 30%, especially 50% or more of the soda content in the P-type zeolite is removed by the acid treatment, and then the temperature is 50 to 600 ° C., especially 100 to 50.
Heat treatment is performed at a temperature of 0 ° C.

The acid to be used may be an inorganic acid or an organic acid without particular limitation, but it is economically preferable to use a mineral acid such as hydrochloric acid, sulfuric acid, nitric acid or phosphoric acid. These acids are preferably used in the form of an aqueous acid solution for the neutralization of zeolite and the elution of alumina.

The acid treatment is preferably performed by converting crystalline zeolite into an aqueous slurry and converting the acid in the slurry. With the addition of acid, the pH shifts to the acid side, and as the neutralization progresses, it tends to shift to the alkali side again and saturate to a certain pH value, but this saturated pH value is 2.0 to 7.0, and particularly 3.5 to 7.0 value. It is desirable to carry out neutralization so that When the saturated pH value is higher than the above range, it is difficult to remove the alkali content of the zeolite as the amorphization of the zeolite proceeds,
When it is lower than the above range, it becomes difficult to carry out the acid treatment while keeping the shape of the produced particles in a predetermined shape. As other conditions for the acid treatment, the temperature is preferably in the range of 20 to 100 ° C., and the concentration of zeolite particles in the slurry is preferably in the range of 5 to 30% by weight.

The acid treatment can be performed in one step or in multiple steps of two or more steps. For example, when only the sodium content is removed, one-step treatment is sufficient, but when a part of the alumina content is also removed, two or more multi-step treatments may be performed.

With this acid treatment alone, the acid-treated product still has the crystal structure of P-type zeolite, but by heat-treating it, the amorphization is completed.

In the present invention, the surface of the particles of the aluminosilicate filler may be coated with metal soap, resin acid soap, various resins or waxes, silane-based or titanium-based coupling agents, silica coating, etc., if desired.

The amorphous aluminosilicate filler of the present invention includes various resins, for example, olefin resins such as polypropylene, polyethylene, crystalline propylene-ethylene copolymer, ion-crosslinked olefin copolymer, ethylene-vinyl acetate copolymer and the like; Thermoplastic polyesters such as polyethylene terephthalate and polybutylene terephthalate; 6-nylon,
Polyamide such as 6,6-nylon; Chlorine-containing resin such as vinyl chloride resin and vinylidene chloride resin; Polycarbonate;
Polysulfones; compounded with a thermoplastic resin such as polyacetal, can be used for the purpose of imparting slip property or anti-blocking property to a resin molded product formed, for example, a biaxially stretched film.

Further, it can be used as a charging agent or a reinforcing agent for a thermosetting resin for molding or a coating material for coating, and also as a ceramic substrate.

In addition, the spherical particles, powder foundation,
Liquid (paste) foundation, baby powder,
It can also be used as a filler for various cosmetic bases such as creams, pharmaceuticals, agricultural chemicals, fragrances, and aromatics.

(Effects of the Invention) According to the present invention, a spherical aluminosilicate, such as P-type zeolite, is heat-treated to be amorphized, so that the surface activity and the adsorptivity are suppressed to a low value and stabilized in the formulation. An inorganic filler was provided.

(Example) Next, the Example of this invention is shown.

In each example, (1) specific surface area, (2) pH, (3)
The particle size by an electron microscope, (4) X-ray diffraction, (5) moisture absorption, (6) chemical composition, and (7) refractive index were measured by the following methods, respectively.

(1) Specific surface area The specific surface area was measured by BET method using Sorptomatic Series 1800 manufactured by Carlo Erba.

(2) pH Conforms to JIS K-5101 24A.

(3) Particle Size by Electron Microscope An appropriate amount of sample fine powder is placed on a metal sample plate, sufficiently dispersed, and metal-coated with a metal coal coating device (Hitachi E-101 type ion sputter) to obtain a photographed sample. Then, the field of view is changed by a scanning electron microscope (S-570 manufactured by Hitachi) by a conventional method, and a 10,000 times electron micrograph image suitable for measuring primary particles is obtained. Representative particles were selected from the particle images in the visual field, the diameter of each particle image was measured using a scale, and the particles were displayed as the particle shape in Examples of the present specification.

(4) X-ray diffraction The sample was passed through a Tyler standard sieve of 200 mesh in advance, dried at 80 ° C for 3 hours in an electric constant temperature oven, and then
After cooling in a desiccator, X-ray diffraction is performed to identify the crystal form.

(Device) Rigaku Denki Co., Ltd. X-ray diffractometer Goniometer PMG-S2 Rate meter ECP-D2 (Measurement condition) Target Cu filter Ni Voltage 35kV Current 20mA Count full scale 4 × 10 ³ C / S time constant 1sec chart Speed 1cm / min Scanning speed 1 ° / min Diffraction angle 1 ° Slit width 0.15mm Measuring range 2θ = 5 ° to 32 ° (5) Moisture absorption amount Approximately 1g of sample is put into a 40 × 40mm weighing bottle whose weight is measured in advance. After drying for 3 hours in an electric constant temperature oven at ℃, cool in a desiccator. Then, the weight of the sample was precisely weighed, placed in a desiccator which was previously adjusted to a relative humidity of 90% with sulfuric acid, and the weight increase after 24 hours was measured to determine the moisture absorption.

(6) Chemical composition The ignition loss (Ig-loss), silicon dioxide (SiO _2), aluminum oxide (Al ₂ O _3), the analysis of sodium oxide (Na ₂ O) was measured according to JIS M 8852. However, when the amounts of aluminum oxide and sodium oxide were very small, the atomic absorption method was also used.

(7) Refractive index Using an Atago digital refractometer RX-1 (manufactured by ATAGO), it was measured by the Larsen oil immersion method.

Example 1 Commercially available reagent water glass (27 wt% sodium silicate SiO ₂
%, Na ₂ O 9.0 wt%), sodium aluminate (Al ₂ O ₃ 2
2.5 wt%, Na ₂ O 15.5 wt%) and caustic soda were used to prepare a dilute sodium silicate solution and a dilute sodium aluminate solution so that the total molar ratio was 16 kg at the following molar ratio.

Na ₂ O / SiO ₂ = 0.7 SiO ₂ / Al ₂ O ₃ = 8.0 H ₂ O / Na ₂ O = 80 Next, in a stainless steel container with an internal volume of about 25, 8.3 kg of dilute sodium silicate solution and dilute sodium aluminate. 7.8 kg was slowly mixed with stirring to obtain a uniform aluminosilicate alkali gel throughout. Next, this aluminosilicate alkali gel was heated to 90 ° C with vigorous stirring and kept at that temperature for 48 hours.
Crystallized over time.

After that, the mother liquor and the solid content were separated by suction and sufficiently washed with water to obtain about 1.7 kg of a P-type zeolite cake having a solid content concentration of 43%.

An electron micrograph of the cake dried in an oven at 80 ° C. for 24 hours is shown in FIG. 6, and an X-ray diffraction pattern thereof is shown in FIG. The powder properties and chemical composition are shown in Table 1 (Sample 1-1).

Next, put sample 1-1 into a magnetic crucible with a diameter of about 5 cm in an amount of 40 to 50 g and a small electric furnace (Tanaka Kagakuki Co., Ltd. Sof-temp IFP-H).
At 500 ℃ (Sample 1-2), 600 ℃ (Sample 1-3), 700 ℃
(Sample 1-4), 800 ° C (Sample 1-5), 900 ° C (Sample 1-
In 6), heat treatment was performed for 1 hour each, and the crystal form and other properties were measured. The results are shown in Table 1.

An X-ray diffraction pattern of the 700 ° C. heat treated product is shown in FIG. 1, and an electron micrograph is shown in FIG. Further 900 ° C, heat treated product X
The line diffraction pattern is shown in FIG.

Example 2 As the raw material silicic acid content, a fine particle siliceous gel obtained by acid-treating the acid clay of Nakajo from Niigata prefecture, which is a smectite group viscous mineral, was used. The preparation method is described below.

Acid white clay from Nakajo, Niigata Prefecture, has a moisture content of 45% by weight in its natural state.
Contains, the main component of which is dry weight% (110 ° C)
Dry) SiO ₂ 72.1, Al ₂ O ₃ 14.2, Fe ₂ O ₃ 3.87, MgO 3.2
5, GaO 1.06, ignition loss 3.15. This raw material acid clay was molded into a cylindrical shape with a diameter of 5 mm and a length of 5 to 20 mm, and the amount equivalent to 1250 Kg in terms of dry matter was put into a 5 m ³ lead beam wood tank, and a sulfuric acid solution 3300 of 47 wt% concentration was added. In addition, after heating to 90 ° C and granular acid treatment for 40 hours, the sulfuric acid salt of the basic component that has reacted with sulfuric acid was removed by washing with a thin sulfuric acid solution and water using a decantation method. It was washed with water until it disappeared to obtain a granular acid-treated product.

The results of chemical composition analysis after the above acid-treated product was dried at 110 ° C. for 2 hours are shown below.

Ig-loss (1000 ℃ × 1hr) 3.75% SiO ₂ 94.34% Al ₂ O ₃ 1.16% Fe ₂ O ₃ 0.16% MgO 0.18% Then, adjust the active silica gel to a concentration of 20% with a ball mill. After wet pulverization, it was used as a silica raw material.

Using the above-mentioned activated silicic acid gel slurry, reagent sodium aluminate (Al ₂ O ₃ 22.5 wt%, Na ₂ O 15.5 wt%) and caustic soda, the dilute activated silicic acid gel slurry and dilute aluminium were prepared so that the total molar ratio would be 16 kg. A sodium acid solution was prepared.

Na ₂ O / SiO ₂ = 0.55 SiO ₂ / Al ₂ O ₃ = 6.0 H ₂ O / Na ₂ O = 65 After that, crystallization was performed in the same manner as in Example 1 to obtain a P-type zeolite.

An electron micrograph of the cake dried for 24 hours in an electric constant temperature oven at 80 ° C. is shown in FIG. 8, and the powder properties and chemical composition are shown in Table 2 (Sample 2-1). Next, the sample 2-1 was processed at 600 ° C. (sample 2-2) and 700 ° C. in the same manner as in Example 1.
(Sample 2-3), 800 ° C (Sample 2-4), 900 ° C (Sample 2
Table 2 shows the results of measuring the crystal form and other properties by heat treatment to (5).

An electron micrograph of the 700 ° C. heat treated product is shown in FIG.

Example 3 100 g of the sample 1-1 obtained in Example 1 was placed in a beaker of 2, 900 ml was added, and after sufficiently dispersing with a magnetic stirrer, 440 ml of hydrochloric acid diluted to 5% with stirring was poured over about 10 hours. Added

After completion of pouring, the mixture was stirred for 1 hour, the mother liquor and the solid content were separated by suction, washed thoroughly with water, and the cake was dried in an electric constant temperature oven at 80 ° C. for 24 hours. The powder properties and chemical composition of this dried product are shown in Table 3 (Sample 3-1).

Further, an X-ray diffraction pattern of the sample 3-1 which was heat-treated at 350 ° C. for 1 hour is shown in FIG. 4, an electron micrograph is shown in FIG. 7, and powder properties are shown in Table 3 (sample 3-2).

Example 4 Sample 2-1 obtained in Example 2 was treated in the same manner as in Example 3 and dried at 80 ° C. Sample 4-1 was obtained. The powder properties and chemical composition of this product are shown in Table 4.

Further, an electron micrograph of powder (Sample 4-2) obtained by heat-treating Sample 4-1 at 350 ° C. for 1 hour is shown in FIG. 10, and powder properties are shown in Table 4.

Application example 1 Polypropylene resin 1 with melt flow rate 1.9g / 10min
2,6-di-t-butyl-p-cresol 0.10 in 00 parts by weight
Parts by weight, 0.05 parts by weight of calcium stearate and 0.8 parts of the sample shown in Table 5 were added, mixed with a super mixer and pelletized at 230 ° C. In addition, synthetic silica (Syloid # 65), calcium char (escaron # 15) as inorganic additives
00), pellets were also similarly prepared without addition of inorganic substances.

Next, this pelut was formed into a sheet-like film using an extruder and stretched 6 times in the length and width to obtain a stretched film of 30 μm.

The transparency, blocking property, and scratch property of these biaxially stretched films were measured. The results are shown in Table 5, and the measuring method was as follows.

(1) Transparency Compliant with ASTM D1003 (2) Blocking property Two films are stacked and a load of 20 kg is applied and the film is left in an oven at 40 ° C for 24 hours. Then, the force required to peel the two films is measured. The blocking property was used.

(3) Scratchability The two scratched films are compared with each other for scratching when they are rubbed with a finger.

◎ Not scratched ○ Slightly scratched △ Scratched ×
It is considerably scratched. Nos. 1 and 2 are samples 2-3 obtained in Example 2 and Example 4.
Sample No. 3 to No. 3 obtained in No. 3 to No. 4 are the No. 1 to No. 2 surface-treated. The surface treatment was performed as follows.

20 g of the sample is thinly spread on a watch glass having a diameter of 10 cm, and a silane coupling agent (SH-6040 manufactured by Toray Silicone is diluted 1: 1 with ethanol) is coated with about 2% by a small sprayer.

Next, stir thoroughly to evaporate the alcohol content and then
After being treated with an electric constant temperature dryer at 150 ° C. for 3 hours, it was ground and used as a sample.

[Brief description of drawings]

Fig. 1, X-ray diffraction diagram of heat-treated Pc zeolite, Fig. 2, X-ray diffraction diagram of raw material Pc zeolite, Fig. 3, X-ray diffraction diagram of nepheline, Fig. 4, Pc zeolite acid treatment → heat treated product X-ray diffraction diagram, Fig. 5, electron microscope photograph of particle shape of heat-treated Pc zeolite, Fig. 6, electron microscope photograph of particle shape of Pc zeolite, Fig. 7, Pc zeolite acid treatment → particle shape of heat-treated product Electron micrograph, Figure 8, Electron micrograph of Pc zeolite particle shape from activated silicic acid, Figure 9, Electron micrograph of heat-treated Pc zeolite particle shape from activated silicic acid, Figure 10, activity Acid treatment of Pc zeolite from silicic acid → Electron micrograph of particle shape of heat treated product.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masami Yawata 18-5-10 Hoshinomiyamachi, Nakajo-machi, Kitakanbara-gun, Niigata Prefecture

Claims (5)

(57) [Claims] 1. An aluminosilicate inorganic filler, which comprises an aluminosilicate having a SiO ₂ content of 50% by weight or more based on the anhydride obtained by acid treatment and / or heat treatment of spherical zeolite, the aluminosilicate being X-ray diffraction is substantially amorphous, and the aluminosilicate has a BET specific surface area of 50 m ² / g or less and RH 90%, room temperature and 24
An inorganic filler consisting of spherical particles having a hygroscopicity of not more than 13% under the conditions of time, the aluminosilicate having an electron microscope primary particle size of 0.2 to 30 μm. 2. The inorganic filler according to claim 1, wherein the aluminosilicate has a BET specific surface area of 30 m ² / g or less and a moisture absorption amount of 7% or less. 3. The inorganic filler according to claim 1, wherein the aluminosilicate has a refractive index of 1.40 to 1.55. 4. The inorganic filler according to claim 1, wherein the aluminosilicate is obtained by firing P-type spherical zeolite at a temperature of 500 to 850 ° C. 5. The aluminosilicate is obtained by subjecting a P-type spherical zeolite to an acid treatment so that at least 30% of the contained soda is removed, and then drying or calcining. Inorganic filler according to item.