JPH0647459B2 - Silica-based filler and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a silica-based filler and a method for producing the same, more specifically, it is difficult to aggregate even if the primary particles have a very small particle size, The present invention relates to a silica-based filler which has good flowability due to its uniform shape, good dispersibility when compounded with it, and good workability in handling and compounding due to its large bulk specific gravity, and a method for producing the same.

(Prior Art and Problems Thereof) Conventionally, as a fine powder of amorphous silica, one produced by a wet method and one produced by a dry method (gas phase method) are known. Wet process silica is produced by treating an alkali metal silicate such as water glass with a mineral acid such as sulfuric acid in water. Such wet process silica has a fine primary particle size of 10 to 20 millimicrons, but a large number of the fine particles aggregate to form a considerably coarse secondary particle. The sizes are not uniform. Therefore, when such a silica is used as a filler, its flowability is poor and the silica is not uniformly dispersed in the medium, so that the filling effect cannot be sufficiently exhibited.

Further, a method of obtaining silica by hydrolyzing a silicic acid ester such as ethyl orthosilicate in water with a strong mineral acid, and a gas phase method produced by hydrolyzing silicon tetrachloride in an oxyhydrogen flame. Although silica has a small particle size, it has a low bulk specific gravity, is difficult to process as a filler, and has a very high production cost.

Therefore, it is difficult to aggregate even particles having a small particle size, and a filler having excellent dispersibility that can be compounded while maintaining the state of primary particles without forming secondary particles, and its easy and economical Manufacturing method is required.

(Object of the Invention) An object of the present invention is to provide a silica-based filler having a high content of silica (SiO ₂ ), hard to aggregate, uniform in shape, good in fluidity and dispersibility, and a method for producing the same. And

(Structure of the invention) The present invention is composed of an acid-treated zeolite, and is composed of substantially amorphous particles containing 75% by weight or more of SiO ₂ on the basis of solid content. Is an independent spherical or cubic particle having a particle size of 0.1 to 10 μm.

Further, the present invention, the crystalline zeolite having a spherical or cubic particle shape, acid treatment under conditions such that the crystal structure is substantially destroyed, but the particle morphology is not substantially impaired. , Alumina free of alkali metal
After producing silica particles and drying or calcining the alumina-silica particles, at least a part of the alumina component is removed by acid treatment under a condition that the particle morphology is not substantially impaired, and then dried. Or a calcination, which is a method for producing a silica-based filler.

(Effects of the Invention) The silica-based filler of the present invention has a particle size of 0.1 to 10 μm.
Are spherical or cubic particles, which are substantially aligned with the specific shape, and the primary particles do not aggregate to form secondary particles. Therefore, the filler of the present invention is blended. When it does, it is dispersed in the state of primary particles. Therefore, in the composition containing the filler of the present invention, the filler is present in a uniform and good dispersed state, and the filling effect is maximized. For example, when the filler of the present invention is blended with various resins, it is possible to remarkably improve the slip property and anti-block property of the resin molded product, further increase the mechanical strength, and produce the effect of not causing coloring or deterioration. .

In particular, when a thermoplastic resin film filled with a conventional silica-based filler was stretched, particularly biaxially stretched, minute irregularities on the surface appeared with a considerably large difference, but the silica-based filler of the present invention was used. When the agent is filled, fine irregularities on the film surface are almost evenly arranged, and the film having a smooth surface is obtained. Further, since the content of silica (SiO ₂ ) is large, there is no disadvantage that it acts on the added plasticizer and other additives to color them. Furthermore, the filler of the present invention is
Since the bulk specific gravity is large, there is an effect that workability during handling and compounding is good.

The production method of the present invention is a method capable of easily and economically producing the filler of the present invention having the excellent characteristics as described above. According to the production method of the present invention, it is possible to produce the filler in which the size of the particles is variously changed in a wide range of the particle size and the particle size is made to be the target particle size, that is, the particle size distribution is relatively narrow. it can. Further, according to the production method of the present invention, it is possible to freely produce those having various changes in the content of silica and / or the content of alumina.
Furthermore, according to the production method of the present invention, even if the size of the particles and the content of silica are changed, almost all of the particles have a particle shape capable of clearly distinguishing from spherical to cubic shapes. The agent may be manufactured.

Silica filler of this invention (a preferred embodiment of the invention), based on the weight of the filler obtained by drying for 3 hours at about 110 ° C., silica SiO ₂ as 75 wt% or more, preferably 80 wt% Above, more preferably 85 wt% or more. In some cases, for example, in the production method of the present invention, the final stage firing temperature is set to about 1000.
The silica filler obtained by firing at a temperature of not less than 0 ° C. may contain 99% by weight or more of silica. When the content of silica is less than 75% by weight, the chemical characteristics of the silica filler are lost. The silica-based filler of the present invention may contain alumina as another component, and the content of alumina is 15% by weight or less,
In particular, it is preferably 10% by weight or less, more preferably 5% by weight or less. Further, the silica-based filler may contain an alkali metal component, and the content thereof is preferably 5% by weight or less, particularly 2% by weight or less as an oxide.

The particle size of the silica-based filler means the particle size according to an electron micrograph (in the case where the particle shape is a cubic shape, it means the length of one side thereof, and in the present specification, both the spherical shape and the cubic shape are included. The particle size) is 0.1 to 10 μm, and can be freely changed according to the purpose of use of the silica-based filler.

The shape of the silica-based filler is mostly spherical or cubic, and is difficult to aggregate. Therefore, this shape is maintained during compounding. An electron micrograph (magnification: 10,000 times) of one example of the silica-based filler of the present invention is shown in FIG. 1-B.

The silica-based filler is substantially amorphous by X-ray diffraction. An X-ray diffraction pattern (Cu-Kα) of one example of the silica-based filler of the present invention is shown in FIG.

The bulk density of the silica-based filler is 0.2 to 1.2.

In the production method of the present invention, the silica-based filler obtained when the temperature of the final stage of drying or firing is set to a temperature of about 800 ° C. or higher is 3% when maintained at a relative humidity of 20% for 24 hours.
It has a water absorption rate of less than or equal to weight%, and has a water absorption rate of less than or equal to 20 weight% when maintained at a relative humidity of 90% for 24 hours, which can significantly reduce the adsorption performance.

In the method for producing the silica-based filler of the present invention, first, the crystalline zeolite is acid-treated under conditions such that its crystal structure is substantially destroyed, but its particle morphology is not substantially impaired. Remove alkali metal.

As the crystalline zeolite, zeolite A, zeolite X, zeolite Y, zeolite P, zeolite S, and the like can be used, but zeolite A is economically preferable. According to the production method of the present invention, the shape of the used zeolite is maintained almost as it is, and in some cases, it is possible to produce a silica-based filler in which the size thereof is slightly reduced, so that the desired silica-based filler can be produced. The crystalline zeolite to be used may be appropriately selected according to the shape and size of the filler.

The acid used for the acid treatment may be an inorganic acid or an organic acid without particular limitation, but economically, an inorganic acid such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, carbonic acid or the like is used. These acids are used in the form of a dilute aqueous solution, preferably a dilute aqueous solution having a concentration of 30% by weight or less.

The acid treatment is performed at 20 to 100 ° C., preferably 30 to 70
It is desirable to carry out at a temperature of ° C under relatively mild conditions. When the acid treatment is performed under severe conditions such that the treatment temperature is higher than 100 ° C. or the acid concentration is increased, the crystalline zeolite and / or the amorphous metal produced by removing the alkali metal component from the crystalline zeolite Alumina-silica particles aggregate, or the surface of the particles dissolves and the particles are broken. Further, if the treatment temperature is lower than 20 ° C., there is no adverse effect on the properties of the amorphous alumina-silica particles produced, but a long time is required for the acid treatment to obtain the desired amorphous alumina-silica particles. It becomes costly and uneconomical.

When an acid is added to an aqueous slurry of crystalline zeolite, the pH naturally shifts to the acidic side as the acid is added, but after the end of the addition, the pH of the liquid shifts to the alkaline side again and tends to be saturated to a certain pH value. . It is desirable for the purpose of the present invention to carry out the neutralization so that the saturated pH, that is, the stable pH is in the range of 7.0 to 3.0, particularly 6.5 to 4.0. That is, when the pH is higher than the above range, it becomes difficult to effectively remove the alkaline component in the zeolite to make it amorphous. On the other hand, when the pH is lower than the above range, the alumina content in the zeolite is also eluted, and it tends to be difficult to leave the cubic particle morphology. The amount of acid used is
It should be sufficient to remove more than 50%, especially more than 70% of the alkali content in the zeolite.

Alumina-silica particles obtained by the above acid treatment,
Next, it is dried or baked. Drying or firing treatment is 11
It is carried out at a temperature in the range of 0 to 750 ° C. Although the treatment time can be shortened as the temperature is raised, it is preferable to treat at a relatively low temperature because particles having a small particle size tend to be fused when treated at a high temperature. Since the treatment time varies depending on the treatment method, it cannot be uniformly determined. For example, instantaneous drying within a few seconds to normal drying within a few hours can be applied. When the alumina-silica particles which have not been subjected to this drying or firing treatment or which have been insufficiently dried or fired are subjected to the acid treatment of the next step, the particles aggregate or fuse during the acid treatment. As a result, the intended silica-based filler having uniform particles cannot be obtained. When the drying or firing temperature is higher than 750 ° C, the alumina-silica particles tend to be crystallized or crystallized at 110 ° C.
Even if the temperature is lower than that, there is no particular problem, but it is not economical because it requires a long time.

The alumina-silica particles dried or calcined as described above are subsequently acid-treated under conditions such that the particle morphology is not substantially impaired, so that at least the alumina component in the alumina-silica particles is Remove a part. This acid treatment also removes acid-soluble components such as alkali metals.

As the acid used for this acid treatment, either an inorganic acid or an organic acid can be used without particular limitation, but economically, an inorganic acid such as hydrochloric acid, sulfuric acid, nitric acid or phosphoric acid is used.

These acids can be used as a high-concentration acid or in the form of a dilute aqueous solution, but under acid treatment,
It is preferably an aqueous solution having a concentration of 5 to 70% by weight. These acids may contain chlorides such as silicon tetrachloride, titanium tetrachloride, calcium chloride, magnesium chloride and the like. The amount of the acid used depends on the amount of alumina and alkali metal to be removed (the alkali metal remaining in the alumina-silica particles can also be removed by this acid treatment).
It is 0.5 mol or more calculated as Al ₂ O ₃ or M ₂ O (where M is an alkali metal).

This acid treatment is preferably carried out at room temperature to the boiling point of the acid aqueous solution, particularly at a temperature of 30 to 100 ° C. with stirring. When the treatment is carried out at a high temperature, the processing time is short, but for those having small particles, it is desirable to carry out the treatment at a relatively low temperature. The degree of acid treatment can be appropriately changed according to the alumina content of the intended silica-based filler, and the more severe the treatment conditions and the longer the time, the more the alumina content in the silica-based filler is increased. The content will decrease. By this acid treatment, it is necessary to remove at least a part of the alumina component in the alumina-silica particles and reduce the content of the alumina component. At least 10% by weight or more of the alumina component in the alumina-silica particles is removed, and the alumina content in the product silica-based filler is 15% by weight or less, more preferably 10% by weight or less, particularly 5% by weight
It is preferable to treat as follows. If necessary, the alumina content can be 0.1% by weight or less.

The silica-based filler obtained by removing the alumina component by this acid treatment can be filtered, washed with water and dried by a conventional method to obtain a product. The silica-based filler thus obtained comprises 75% by weight or more of SiO ₂ and is composed of independent spherical or cubic substantially amorphous primary particles having a particle size of 0.1 to 10 μm and having a particle size of 300 m ² BET non-surface area of / g or more.

The silica-based filler can be dried or calcined at a temperature of 110 ° C. or higher to reduce the water absorption and BET specific surface area of the filler. The upper limit of the temperature of the drying or calcination treatment is a temperature lower than the temperature at which the independence of the primary particles is lost by sintering, and the zeolite as a starting material or the silica-based filler before the drying or calcination treatment is used. It is generally 1500 ° C., though it depends on the properties. Baking temperature is 600 ℃
To a certain extent, the BET non-surface area of the silica-based filler does not change much, but calcination at higher temperatures than that of the silica-based filler, as seen in ordinary silica-based particles.
BET non-surface area is reduced. When the drying or baking treatment time is lengthened, the water absorption and the BET non-surface area of the silica-based filler tend to decrease. Therefore, a silica-based filler having a desired water absorption and a BET non-surface area can be produced by appropriately changing the temperature and time of the drying or firing treatment.

Further, the surface area of the silica-based filler can be reduced by hydrothermally treating the silica-based filler obtained by the acid treatment. The hydrothermal treatment is performed in the presence of water vapor at a temperature of 12
It can be carried out under pressure at a temperature of 0 to 250 ° C. Further, it is possible to obtain SiO _{2 of} 75% or more by repeating treatment of the zeolite as it is or after firing as an extremely dilute suspension with carbonated water or a dilute mineral acid of 1 N or less. The treatment time is long and the yield is low, which is not economically preferable.

The silica-based filler of the present invention has a particle surface, by a means known per se, a silane-based, titanate-based, zircoaluminate-based coupling agent, fatty acid, fatty acid metal soap, resin acid metal soap, or resin. Can also be coated with.

The silica-based filler of the present invention includes various resins, for example, olefin resins such as polypropylene, polyethylene, crystalline propylene-ethylene copolymer, and ion-crosslinked olefin copolymer; thermoplastic resins such as polyethylene terephthalate and polybutylene terephthalate. Polyester; Polyamide such as 6-nylon, 6,6-nylon, 6,8-nylon; Chlorine-containing resin such as vinyl chloride resin, vinylidene chloride resin; Polycarbonate; Polysulfone; Polyacetal and other thermoplastic resins It can be used to impart a slip property or an anti-blocking property to the formed resin molded product. Further, it can be added to a kneading composition or a liquid composition for forming a coating to impart antiblocking property to the coating. For such applications, the amorphous silica-based filler of the present invention may be added in an amount of 0.001 to 10 parts by weight, particularly 0.01 to 3 parts by weight, per 100 parts by weight of the resin.
Used in parts by weight. It can also be blended with thermosetting resins such as epoxy resins and phenol resins used for IC plastic packages.

The amorphous silica-based filler of the present invention has little alkali content, is slightly acidic, does not cause coloring or deterioration of the resin, and is also well kneaded with the resin, so that it can be used as a filler for the resin, Further, particularly when an alkaline silica-based filler is required, it can be blended with the resin as an alkaline silica-based filler in which a basic component such as calcium, magnesium, or barium is reconstituted as necessary. In particular, those made of hydrous silica can be blended with the above-mentioned resin or various thermosetting resins as a flame-retardant filler to be used for various purposes.

Further, the silica-based filler of the present invention utilizes the above-mentioned features, and is used as a cosmetic filler, a paint filler, a matting agent, a paper filler, a coating agent, a catalyst carrier, an agrochemical carrier, It can be used as a ceramic raw material or the like.

Next, examples of the present invention will be described. In each embodiment, (1) X
Crystallinity by line diffraction, (2) specific surface area, pore volume, (3) particle size by electron microscope, (4) chemical composition, (5) moisture absorption and
(6) The particle size distribution was measured by the following methods.

(1) Crystallinity by X-ray diffraction The sample was passed through a Tyler standard sieve of 200 mesh in advance, dried at 110 ° C for 3 hours in an electric constant temperature oven, then allowed to cool in a desiccator and then subjected to X-rays. Measure the diffraction,
The crystallinity is calculated according to the following formula.

(Device) Rigaku Denki Co., Ltd. X-ray diffractometer Goniometer PMG-S2 Rate meter ECP-D2 (Measurement conditions) Target Cu filter Ni voltage 35 kV current 20 mA 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 2 ^θ = 5 ° to 32 ° (2) Specific surface area and pore volume It was measured by BET method using a Sorptomatic Series 1800 manufactured by Carlo Erba.

(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 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. Ten representative particles were selected from the cubic particle image in the visual field, the diameter of each cubic particle image was measured using a scale, and the particle size was displayed as the primary particle diameter in the examples of the present specification.

(4) Chemical composition Ignition loss (Ig-loss), silicon dioxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), and sodium oxide (Na ₂ O) were analyzed 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.

(5) Moisture absorption amount Approximately 1 g of the sample is placed in a 40 × 40 mm weighing bottle whose weight has been measured in advance, dried for 3 hours in an electric oven at 150 ° C., and then left to cool in a desiccator. Then, the weight of the sample was precisely weighed and placed in a desiccator adjusted to 20% and 90% relative humidity with sulfuric acid in advance, and the increase in weight after 24 hours was measured to determine the amount of moisture absorption.

(6) Particle size distribution The measurement was performed using a Micron Fort Sizer SKN-1000 manufactured by Seishin Enterprise. A 0.2% sodium pyrophosphate aqueous solution is used as the dispersion medium. At the beginning of measurement, adjust the zero point and swing width of the recorder using only the dispersion medium. The light transmission amount of the blank is adjusted to Log 1.95 of the recording paper.

The sample dispersion liquid was prepared as follows. 200 ml
Take 100 ml of the dispersion medium in a beaker, add about 15 mg of the sample, and disperse with a SK Disperser (ultrasonic disperser) for about 2 minutes. At this time, they are simultaneously stirred by a stirrer. After the dispersion is completed, the liquid is cooled or heated until the liquid temperature reaches a predetermined temperature. This dispersion is filled up to the marked line of the glass cell while maintaining a uniform dispersion state. When the cell is set in the cell holder and the light source lamp is turned on, the pen of the recorder is Log1.3-Log
If it is between 1.4, the dispersion liquid concentration is appropriate. If Log is 1.3 or less, it is too dark, and if Log is 1.4 or more, it is too thin, and therefore re-preparation is performed. Maximum particle size is 3
The condition is 0 μ.

Example 1 4A type zeolite powder having a primary particle diameter of about 0.9 μm (Mizusawa
Product name "Mizuka Sieves" manufactured by Chemical Industry Co., Ltd. 4A
P ") 400 g are dispersed in 3600 ml of water and stirred under stirring.
Sodium in olite (Na₂0) with respect to the number of moles of O).
6 moles of sulfuric acid (H₂SO_Four10% by weight aqueous solution containing
I added it completely.

After adding sulfuric acid, the mixture was stirred for additional 30 minutes, then the solid was filtered off and washed thoroughly with warm water of about 40 ° C. The obtained filter cake was dried in an electric constant temperature oven at 110 ° C. for 24 hours and then pulverized by a sample mill by a conventional method. The properties of the obtained powder (raw material 1) are shown in Table 1. An electron micrograph of the 4A type zeolite powder is shown in FIG. 1-A.

50 g of the above powder was precisely weighed and placed in a beaker No. 3, pure water 2 was added thereto, and the powder was dispersed by stirring for 5 minutes with a magnetic stirrer. Then, to this dispersion was added under stirring the reagent special grade sulfuric acid in an amount of 5.0 mol times the total mol number of Al ₂ O ₃ and Na ₂ O in the powder. At this time, the liquid temperature rose to about 70 ° C. Stirring was continued for another 20 minutes after the addition of sulfuric acid, then the solid was filtered off using No. 5A filter paper and washed thoroughly with water.

The obtained solid was dried in an electric constant temperature oven at 110 ° C. for 6 hours, and its weight was precisely weighed to calculate the acid-insoluble amount (% by weight). Table 2 shows the measurement results of the properties of the powder [silica-based filler (Sample 1)].

In addition, instead of the powder used for the second stage acid treatment, 4A
The results of performing the second stage acid treatment in the same manner as above except that the type zeolite powder is used are also shown in Table 2.

Example 2 A powdery silica-based filler was obtained in the same manner as in Example 1 except that the amount of sulfuric acid used in the second stage acid treatment was changed to 10 times the molar amount. . The amount of acid-insoluble matter and the properties of the powder (Sample 2) are shown in Table 2. An electron micrograph of the powder is shown in Figure 1-B.

Example 3 In Example 1, the amount of sulfuric acid used in the first stage acid treatment was 0.
A silica-based filler was obtained by the same treatment as in Example 1 except that the 6-fold molar ratio was changed to 0.8-fold molar ratio.

Table 1 shows the properties of the powder (raw material 2) dried by the first stage acid treatment, and Table 2 shows the properties of the silica-based filler (sample 3).

Example 4 A silica-based filler (Sample 4) was obtained in the same manner as in Example 3, except that the amount of sulfuric acid used in the acid treatment in the second step was changed to 10 mol times. It was The properties are shown in Table 2.

Examples 5 to 8 In Example 2, the temperature for drying the first-stage acid treatment was 250 ° C (Example 5), 350 ° C (Example 6), and 450 ° C (Example 7). And 550 ° C. (Example 8), respectively, and the drying or firing treatment was repeated.
6, 7, 8) were obtained. The properties are shown in Table 2.

Example 9 Silica-based filler powder (Sample 2) 10 obtained in Example 2
g was placed in a 500 ml beaker, 300 ml of a 20% sulfuric acid aqueous solution prepared using special grade sulfuric acid was added thereto, and the mixture was subjected to acid treatment at 80 ° C. for 6 hours while stirring with a magnetic stirrer.

Then, the same treatment as in the second stage after the acid treatment in Example 2 was carried out to obtain a silica-based filler (Sample 9). The chemical composition and properties are shown in Table 3. The analysis of Fe, Mg and Ca was carried out by the atomic absorption method after melting.

Examples 10 and 11 Example 4 was repeated except that nitric acid (Example 10) or hydrochloric acid (Example 11) was used in the same molar amount in place of the sulfuric acid used in the second stage acid treatment in Example 4. A silica-based filler was obtained in the same manner as in. Table 1 shows the properties of the first-stage acid-treated and dried powder, and the silica-based filler (Sample 10,
The properties of 11) are shown in Table 2.

Example 12 In Example 2, Y type was used instead of 4A type zeolite powder.
Zeolite powder (manufactured by Mizusawa Chemical Industry Co., Ltd., trade name "Mizu"
Cassipes )) Is used in the first stage acid treatment.
The amount of acid is Na in the zeolite.₂2.0 mole times O
Silica-based material in the same manner as in Example 2 except that
A filler (Sample 12) was obtained.

Table 4 shows the properties of the zeolite, the properties of the first-stage acid-treated powder and the dry-treated powder (raw material 3), and the properties of the silica-based filler are shown in Table 5. An electron micrograph of the Y-type zeolite is shown in FIG. 3-A, and an electron micrograph of the silica-based filler is shown in FIG. 3-B.

Example 13 In Example 12, drying temperature 1 after the second stage acid treatment
A silica-based filler (Sample 1) was prepared in the same manner as in Example 12 except that the temperature was changed from 10 ° C. to 450 ° C. and drying or firing was performed.
3) was obtained. The properties are shown in Table 5.

Example 14 In the same manner as in Example 12, except that a P-type zeolite powder synthesized from a commercially available sodium silicate and sodium aluminate by a known method was used in place of the Y-type zeolite powder in Example 12, the silica-based powder was used. A filler (Sample 14) was obtained.

Table 6 shows the properties of the P-type zeolite, properties of the first-stage acid-treated and dried powder (raw material 4), and Table 7 shows the properties of the silica-based filler.

In addition, the electron micrograph of the P-type zeolite powder is shown in No. 4-
In Fig. A, an electron micrograph of the silica-based filler is shown in Fig. 4-B.
Shown in the figure.

Example 15 In Example 14, drying temperature 1 after the second stage acid treatment
Silica-based filler (Sample 15) was carried out in the same manner as in Example 14 except that the temperature was changed from 10 ° C to 450 ° C and the drying or firing treatment was performed.
Got The properties are shown in Table 7.

Example 16 10 g of each of the silica-based fillers produced by the method described in Example 9 was heated at 300 ° C. (Sample 16-
1), 500 ° C, 600 ° C, 700 ° C, 800 ° C, 10
A silica-based filler was manufactured by firing at 00 ° C., 1200 ° C. and 1500 ° C. for 3 hours each. The obtained silica-based filler Ig-loss (%), SiO ₂ content (%), specific surface area, moisture absorption,
The pore volume is shown in Table 8.

Example 17 Silica-based filler powder (Sample 2) 30 obtained in Example 2
g was placed in a beaker 2 and 900 ml of a 20% sulfuric acid aqueous solution prepared by using special grade sulfuric acid was added to the beaker, followed by acid treatment at 80 ° C. for 6 hours while stirring.

Then, the silica powder obtained by the same treatment as the treatment after the second stage acid treatment in Example 2 was divided into 3 equal parts, and 1% of hydroxides such as calcium, magnesium and barium were respectively obtained.
The slurry and 1% solution were added and treated at 80 ° C. for 30 minutes with stirring.

Then, after excessive separation, the silica-based filler according to the present invention having a uniform alkaline shape was obtained by firing at 300 to 900 ° C. for 30 minutes each. The shape is shown in Table 9.

The aqueous dispersion pH was measured by preparing a 5% by weight dispersion of each sample powder.

Application Example 1 100 parts by weight of polypropylene resin having a melt flow rate of 1.9 g / 10 min, 0.10 parts by weight of 2,6-di-t-butyl-p-cresol, and 0.0 of calcium stearate.
5 parts by weight and 0.02 to 0.10 of spherical silica (Sample 2) of about 1.0 μm prepared in Example 2 were added, mixed with a super mixer and pelletized at 230 ° C. In addition, as Comparative Examples 1, 2, and 3, synthetic silica (0.8 μ) as an inorganic additive, calcium char (Escalon # 1500), and no inorganic substance were pelletized in the same manner.

Next, the pellets were formed into a sheet-like film by using an extruder and stretched 6 times in the length and width to obtain a stretched film of 30μ.

These biaxially stretched films were measured for transparency, blocking property, slip property, and scratch property. First result
Although shown in Table 0, the measuring method was as follows.

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

(3) Sliding property Compliant with ASTM D1894 (4) Scratchability Comparison is made on the degree of scratching when two films are rubbed with a finger.

◎ Not scratched ○ Slightly scratched △ Scratched × Very scratched

[Brief description of drawings]

FIG. 1-A is an electron micrograph showing the particle structure of 4A type zeolite powder, and FIG. 1-B is an electron micrograph showing the particle structure of the silica-based filler (Sample 2) obtained in Example 2. FIG. 2 is an X-ray diffraction diagram of the silica-based filler obtained in Example 2, and FIG. 3-A is an electron micrograph showing the particle structure of Y-type zeolite powder. FIG. 4B is an electron micrograph showing the particle structure of the silica-based filler (Sample 12) obtained in Example 12, and FIG.
FIG. 4-B is an electron micrograph showing a particle structure of the zeolite zeolite powder, and FIG. 4-B is an electron micrograph showing a particle structure of the silica-based filler (Sample 14) obtained in Example 14.

Claims (2)

[Claims] 1. An acid-treated zeolite, comprising substantially amorphous particles containing 75% by weight or more of SiO ₂ on a solids basis, each particle having a particle diameter of 0.1 to 10.
A silica-based filler characterized by being independent spherical or cubic particles having a size of μm. 2. A crystalline zeolite having a spherical or cubic particle shape is treated with an acid under conditions such that the crystal structure is substantially destroyed but the particle morphology is not substantially impaired. Alumina-silica particles from which alkali metal components have been removed are produced, and after the alumina-silica particles are dried or calcined, they are acid-treated under conditions such that the particle morphology is not substantially impaired, and the alumina component A method for producing a silica-based filler, which comprises removing at least a part of, and then drying or firing.