JP5159599B2 - Thermoplastic resin composition and film - Google Patents

Description

  The present invention relates to a resin composition, and particularly to a film excellent in gas impermeability and transparency.

  As a gas-impermeable film material, a molding material, a dispersant, a thickener, and a binder are blended with an inorganic material and used as a gas barrier material. For example, a carboxyl group-containing high hydrogen gas-bonding resin (A) having two or more carboxyl groups in the molecule, such as polyacrylic acid, and a hydroxyl group having two or more hydroxyl groups in the molecular chain, such as starches A composition is formed by 100 parts by weight of a mixture having a weight ratio A / B = 80/20 to 60/40 of the high hydrogen gas-binding resin (B) and 1 to 10 parts by weight of an inorganic layered compound such as clay mineral. It is known that when a film having a thickness of 0.1 to 50 μm produced from this composition is subjected to heat treatment and electron beam treatment, the film exhibits gas barrier properties (see Patent Document 1).

  By laminating a layer composed of a resin composition containing an inorganic stratiform compound and a resin between two polyolefin resin layers, it is possible to obtain a laminated film that is excellent in moisture resistance and gas barrier properties and can be applied to food packaging. Yes (see Patent Document 2).

  The film containing a layered inorganic compound as a main constituent is (1) composed of a layered inorganic compound and a water-soluble resin, (2) the weight ratio of the layered inorganic compound to the total solid is 70% or more, (3) all A transparent material characterized in that the light transmittance exceeds 80%, (4) has a gas barrier property, and (5) has a mechanical strength that can be used as a self-supporting film (Patent Document 3). .

However, in a gas-impermeable film material, transparency may be lowered due to an added inorganic compound or the like, and improvement has been desired.
Japanese Patent Laid-Open No. 10-231434 JP 7-251489 A JP 2007-63118 A

  An object of this invention is to provide the film material which is excellent in gas impermeability and transparency.

  1st invention of this application is the range whose average particle diameter measured by a thermoplastic resin 100 weight part and a dynamic light-scattering method is 10-100 nm, and a breadth / major axis ratio is 0.01-0.7 A thermoplastic resin composition comprising 5 to 60 parts by mass of flaky composite silica fine particles containing 25 to 90% by mass of smectite-type layered fine particles.

A second invention of the present application is the thermoplastic resin composition, wherein the flaky composite silica fine particles are formed by forming a silica layer on the surface of the smectite-type layered fine particles.
A third invention of the present application is the thermoplastic resin composition, wherein the flaky composite silica fine particles are obtained by growing particles with a silica component using smectite-type layered fine particles as core particles.

A fourth invention of the present application is the thermoplastic resin composition, wherein the smectite-type layered fine particles are composed of any of the trioctahedral smectites shown in the following (1) to (5): It is a thing.
(1) Saponite [X _0.33 (Mg ₃ ) (Al _0.33 Si _3.67 ) O ₁₀ (OH) ₂ .nH ₂ O
],
(2) Iron saponite _{[X 0.33 (Mg, Fe)} 3 (Al 0.33 Si 3.67) O 10 (OH) 2 · nH 2 O],
(3) Hectorite [X _0.33 (Mg _2.67 Li _0.33 ) Si ₄ O ₁₀ (OH) ₂ .nH ₂ O]
,
(4) sauconite _{[X 0.33 (Mg, Zn)} 3 (Si 3.67 Al 0.33) O 10 · nH 2 O],
(5) Steven site [X _{0.33 / 2} (Mg _2.97 ) Si ₄ O ₁₀ (OH) ₂ · nH ₂ O]
(However, X is K, Na, 1 / 2Ca or 1 / 2Mg. N is n ≧ 0.)
According to a fifth invention of the present application, the thermoplastic resin is selected from a polyvinyl chloride resin, a polyvinylidene chloride resin, a polyvinyl acetate resin, a polyethylene resin, or a polyethylene terephthalate resin. It is a composition.

  6th invention of this application is a film which consists of said thermoplastic resin composition.

  The film comprising the thermoplastic resin composition according to the present invention exhibits excellent gas impermeability and is excellent in transparency. For example, it is suitable as a packaging film for foods.

  The thermoplastic resin composition according to the present invention is obtained by dispersing flaky composite silica fine particles in which a silica layer is formed on the surface of smectite-type layered fine particles as a filler. Due to the structural characteristics of the flaky composite silica fine particles, the film made of this thermoplastic resin composition exhibits practical gas impermeability, and further, excellent transparency due to the influence of the silica component of the flaky composite silica fine particles. It is possible to show gender. The thermoplastic resin composition according to the present invention and the film comprising the thermoplastic resin composition will be described below.

[Thermoplastic resin composition]
The thermoplastic resin composition according to the present invention includes the following (A) and (B). (A) 100 parts by weight of thermoplastic resin (B) The average particle diameter measured by the dynamic light scattering method is in the range of 10 to 100 nm, and the short diameter / long diameter ratio is in the range of 0.01 to 0.7. 5 to 60 parts by mass of flaky composite silica fine particles containing 25 to 90% by mass of type-layered fine particles The blending ratio of the flaky composite silica fine particles to the thermoplastic resin is about 100 parts by mass of the thermoplastic resin. The range of 5 to 60 parts by mass of fine composite silica particles is preferred. When the amount of the flaky composite silica fine particles is less than 5 parts by mass, the gas impermeability of the film made of the thermoplastic resin composition may be insufficient. It is not always necessary to blend the flaky composite silica fine particles in excess of 60 parts by mass. A more preferable blending ratio of the flaky composite silica fine particles includes a range of 8 to 55 parts by mass.
Thermoplastic Resin As the thermoplastic resin, a known thermoplastic resin can be used. Examples of such thermoplastic resins include polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polyvinyl chloride, polyvinylidene chloride, polyimide, polyamide, polyester, polyvinyl alcohol, polyvinyl acetate, and polyethylene terephthalate. Other thermoplastic resins, and other copolymerization or graft copolymerization components may be appropriately used as necessary.

Flaky Composite Silica Fine Particles The flaky composite silica fine particles according to the present invention usually have an average particle diameter measured by a dynamic light scattering method in the range of 10 to 100 nm and a minor axis / major axis ratio of 0.01 to 0.00. 7 and exists in a state of a flaky composite silica fine particle dispersion in which flaky composite silica fine particles containing 25 to 90% by mass of smectite-type layered fine particles are dispersed in a dispersion medium. Since the flaky composite silica fine particles are those obtained by growing smectite-type layered fine particles as core particles and using a silica source such as a silicic acid solution, it can be said that a silica layer is formed on the surface of the smectite-type layered fine particles.

1) Average particle diameter The average particle diameter of the flaky composite silica fine particles measured by the dynamic light scattering method is preferably in the range of 10 to 100 nm. This particle size range is preferable in that excellent polishing characteristics can be obtained when used as an abrasive. In the production of the flaky composite silica fine particle dispersion, smectite-type layered particles are used as the core particles, but it is not easy to obtain smectite-type layered particles having an average particle diameter of less than 10 nm. Moreover, although it is possible to prepare flaky composite silica fine particles having an average particle diameter exceeding 100 nm, a more preferable average particle diameter range of the flaky composite silica fine particles is recommended to be in the range of 15 nm to 60 nm.

2) Particle minor axis / major axis ratio The flaky composite silica fine particles are flaky or substantially flaky particles similar to the structure of the smectite-type layered particle as a raw material. The short diameter / major diameter ratio of the flaky composite silica fine particles is preferably in the range of 0.01 to 0.7. This range is dependent on the shape of the smectite type layered particles comprising core particles.

3) Particle composition The flaky composite silica fine particles are formed from silica and smectite-type layered fine particles. The content ratio of the smectite-type layered fine particles in the flaky composite silica fine particles is usually 25 to 90% by mass,
The content ratio of silica is preferably in the range of 10 to 75% by mass. When the content ratio of the smectite-type layered fine particles is less than 25% by mass, the silica component may be excessively increased and the flakes may not be formed. Further, when the content ratio of the smectite-type layered fine particles exceeds 90% by mass, the silica layer may not be sufficiently formed on the surface of the smectite-type layered fine particles. A dispersion containing such flaky composite silica fine particles may be used. When applied to polishing applications, good polishing performance may not be exhibited. A more preferable content ratio of the smectite-type layered fine particles in the flaky composite silica fine particles is 28 to 88% by mass, and a silica content of 12 to 72% by mass is recommended.

  The smectite-type layered fine particles are composed of a clay mineral having the following general formula:

（式中、ＸはＫ，Ｎａ，１／２Ｃａ及び１／２Ｍｇの少なくとも一種であり、ｍは０．２５〜０．６であり、Ｙ²⁺はＭｇ²⁺、Ｆｅ²⁺、Ｍｎ²⁺、Ｎｉ²⁺、Ｚｎ²⁺及びＬｉ⁺の少なく
とも一種であり、Ｙ³⁺はＡｌ³⁺、Ｆｅ³⁺、Ｍｎ³⁺及びＣｒ³⁺の少なくとも一種であり、ＺはＳｉ及びＡｌの少なくとも一種であり、ｎＨ₂Ｏは層間水である。）
なお、（Ｙ²⁺，Ｙ³⁺）においてＹ²⁺，Ｙ³⁺は、Ｙ²⁺及び／又はＹ³⁺の意である。また、上記式で、Ｘは層間、Ｙは八面体、Ｚは四面体の陽イオンを表す。

(In the formula, X is at least one of K, Na, 1 / 2Ca and 1 / 2Mg, m is 0.25 to 0.6, and Y ²⁺ is Mg ²⁺ , Fe ²⁺ , Mn ^2+. , Ni ²⁺ , Zn ²⁺ and Li ⁺ , Y ³⁺ is at least one of Al ³⁺ , Fe ³⁺ , Mn ³⁺ and Cr ³⁺ , and Z is at least one of Si and Al NH ₂ O is interlayer water.)
In (Y ²⁺ , Y ³⁺ ), Y ²⁺ and Y ³⁺ mean Y ²⁺ and / or Y ³⁺ . In the above formula, X represents an interlayer, Y represents an octahedron, and Z represents a tetrahedral cation.

  Of these, trioctahedral smectite is preferably used. Specifically, the trioctahedral smectite of any one of the following (1) to (5) is preferable. These smectites can be obtained as particles or particle dispersions having an average particle size of about 10 to 100 nm. Since these smectites have a flaky structure, they are preferably used as seeds in the production method of the present invention.

(1) Saponite [X _0.33 (Mg ₃ ) (Al _0.33 Si _3.67 ) O ₁₀ (OH) ₂ .nH ₂ O
],
(2) Iron saponite _{[X 0.33 (Mg, Fe)} 3 (Al 0.33 Si 3.67) O 10 (OH) 2 · nH 2 O],
(3) Hectorite [X _0.33 (Mg _2.67 Li _0.33 ) Si ₄ O ₁₀ (OH) ₂ .nH ₂ O]
,
(4) sauconite _{[X 0.33 (Mg, Zn)} 3 (Si 3.67 Al 0.33) O 10 · nH 2 O],
(5) Steven site [X _{0.33 / 2} (Mg _2.97 ) Si ₄ O ₁₀ (OH) ₂ · nH ₂ O]
(Where X is selected from K, Na, 1 / 2Ca or 1 / 2Mg)
Part of the smectite-type layered fine particles can be synthesized. For example, saponite is commercially available as a synthetic product (“Smecton SA”, manufactured by Kunimine Kogyo Kagaku Co., Ltd.). In the present invention, any of natural mineral smectite-type layered fine particles or artificially synthesized smectite-type layered fine particles can be used.

4) Specific surface area The specific surface area of the flaky composite silica fine particles, which is the dispersoid of the flaky composite silica fine particle dispersion according to the present invention, is usually preferably in the range of ²⁰ to 400 m ² / g.
The flaky composite silica fine particle dispersion according to the present invention can be produced, for example, by the following production method.

[Method for producing flaky composite silica fine particle dispersion]
The method for producing a flaky composite silica fine particle dispersion according to the present invention comprises adding a predetermined amount of a silica component such as silicic acid solution to a water-based dispersion of smectite-type layered fine particles at a predetermined rate, thereby The growth of smectite-type layered fine particles is performed.

In the production method of the present invention, an aqueous dispersion of flaky trioctahedral smectite-type layered fine particles having an average particle diameter measured by a dynamic light scattering method in the range of 10 to 100 nm is obtained with a solid content concentration of 0.01. The dispersion is adjusted to 10 to 10% by mass and pH 8 to 12.5, and maintained at 60 to 200 ° C., with respect to 100 parts by mass of the hydrated particles of the trioctahedral smectite type particles, the following (i) After adding 5 to 4900 parts by mass (silica conversion) of any silica source shown in (iv) at an addition rate of 0.1 to 10 parts by mass (silica conversion) / min, aging at 60 to 200 ° C. By doing so, the silica-based composite fine particle dispersion is produced.
Silica source:
(I) Silica solution (silica concentration 1 to 10% by mass)
(Ii) Aqueous silicate aqueous solution (silica concentration 0.1 to 5% by mass)
In addition, as an alkali here, sodium or potassium is preferable.
(Iii) Silicic acid solution (silica concentration 2 to 6% by mass) and alkali silicate aqueous solution (silica concentration 0.1 to 5% by mass)
In addition, as an alkali here, sodium or potassium is preferable.
(Iv) Any of the above (i) to (iii) and an aqueous inorganic salt solution (excluding an aqueous alkali silicate solution, a solid content concentration of 0.1 to 5% by mass)

  As the trioctahedral smectite-type layered fine particles applied to the production method according to the present invention, those having an average particle diameter measured by a dynamic light scattering method in the range of 10 to 100 nm are preferably used. It is not easy to obtain trioctahedral smectite-type layered fine particles having an average particle diameter of less than 10 nm. Further, trioctahedral smectite-type layered fine particles having an average particle diameter exceeding 100 nm are not necessarily required.

  The solid content concentration of the aqueous dispersion of the trioctahedral smectite-type layered fine particles is preferably in the range of 0.01 to 10% by mass. If it is less than 0.01% by mass, it is not easy to prepare a flaky composite silica fine particle dispersion under practical conditions. When the amount exceeds 10% by mass, the viscosity becomes too high and there is a problem such as aggregation during particle growth.

  The aqueous dispersion of the trioctahedral smectite-type layered fine particles is preferably used after adjusting the pH in the range of 8 to 12.5. If the pH is less than 8, gelation may occur by adding a silica source. When the pH exceeds 12.5, problems such as aggregation due to dissolution of silica tend to occur. About this pH range, the range of 9-12 is recommended more suitably. Sodium hydroxide or the like is appropriately used for adjusting the pH of the aqueous dispersion.

  The trioctahedral smectite-type layered fine particles preferably have a minor axis / major axis ratio in the range of 0.01 to 0.7. When the minor axis / major axis ratio is within this range, it is easy to obtain flaky composite silica fine particles that satisfy the above-mentioned requirements.

  When adding the silica source, it is preferable to keep the aqueous dispersion in a temperature range of 60 to 200 ° C. When the temperature is lower than 60 ° C., the progress of particle growth is slow and is not practical. It is not necessary to advance the particle growth while maintaining the temperature above 200 ° C.

Any of the above (i) to (iv) is used as a silica source used for particle growth.
The silicic acid solution is obtained by dealkalizing a water-soluble silicate selected from alkali metal silicate, tertiary ammonium silicate, quaternary ammonium silicate or guanidine silicate. The concentration of the silicic acid solution is preferably in the range of 1 to 10% by mass, more preferably 2 to 7% by mass in terms of SiO ₂ . The pH of the silicic acid solution is preferably in the range of 1 to 5.0, more preferably 1.5 to 4.0. In particular, when the pH of the silicic acid solution is in the range of 1.5 to 4.0, the residual cation in the acidic silicic acid solution is small and the stability is excellent.

  Examples of the alkali silicate aqueous solution include aqueous solutions of potassium silicate (potassium water glass), sodium silicate (sodium water glass), and the like. The silica concentration of the alkali silicate aqueous solution is preferably in the range of 0.1 to 5% by mass. Moreover, it is preferable that pH of alkali silicate aqueous solution exists in the range of 9-12, Furthermore, 10-11.5.

When using both of the silicate solution and the alkali silicate aqueous solution, the concentration of the silicic acid solution is preferably in a range of from 2 to 6% by weight in terms of SiO _2, the concentration of the alkali silicate aqueous solution in terms of SiO ₂ The range of 0.1-5 mass% is preferable.

  As the inorganic salt aqueous solution, sodium aluminate, aluminum sulfate, aluminum chloride, aluminum nitrate, aluminum phosphate, or the like can be used. The inorganic salt aqueous solution is added together with the above (i), (ii) or (iii) for the purpose of making it porous or forming a solid acid.

As in (iii) and (iv) above, when two or more kinds of liquids are used as the silica source, these can be added simultaneously or sequentially.
The addition amount of the silica source is preferably in the range of 5 to 1500 parts by mass (silica conversion) with respect to 100 parts by mass of the trioctahedral smectite type layered fine particles. If the addition amount is less than 5 parts by mass, it may be difficult to provide a sufficient silica coating on the core particles. When the addition amount exceeds 1500 parts by mass, the particle growth proceeds excessively, and as a result, it does not remain in the form of flakes, but may be, for example, spherical fine particles.

  The addition rate of the silica source is preferably in the range of 0.1 to 10 parts by mass / minute with respect to 100 parts by mass of the trioctahedral smectite type layered fine particles. When the addition rate is less than 0.1 parts by mass / minute, the growth rate is slow, and the stability of the silicic acid solution used for the addition deteriorates.

When the addition rate exceeds 10 parts by mass / min, the silica deposition rate is high and new nuclei are likely to be generated, which is not preferable.
By adding the silica source, silica adheres mainly in the thickness direction of the smectite-type layered fine particles to form flaky composite silica fine particles.

  After the addition of the silica source, aging is performed to grow the fine particles by further attaching silica to the formed flaky composite silica fine particles. The aging temperature is preferably in the range of 60 to 200 ° C, and more preferably in the range of 80 to 150 ° C. When the aging temperature is lower than 60 ° C., the particle growth rate is low and the particles aggregate. When the temperature is higher than 200 ° C., productivity is poor, which is not preferable.

  The aging time is preferably in the range of 0.5 to 5 hours, and more preferably in the range of 1 to 3 hours. When the aging time is less than 0.5 hours, the uniformity of the particle size distribution is inferior, and when it exceeds 5 hours, the amount of scale tends to increase.

[Method for producing thermoplastic resin composition]
Regarding the method for producing a thermoplastic resin composition according to the present invention, usually, a flaky composite silica fine particle dispersion is mixed with a solution obtained by dissolving a thermoplastic resin in water or an organic solvent, and the thermoplastic resin composition is selected according to the thermoplastic resin. It hardens | cures on conditions and it is set as a thermoplastic resin composition. When the thermoplastic resin is dispersed in an organic solvent, it is necessary to replace the flaky composite silica fine particle dispersion with a solvent to make the solvent an organic solvent. If necessary, the surface of the flaky composite silica fine particles must be treated with a silane coupling agent to impart dispersibility in an organic solvent.

  About the film which consists of a thermoplastic resin composition concerning this invention, you may manufacture by a extending | stretching process from a thermoplastic resin composition, and may shape | mold a thermoplastic resin composition in a film form previously.

  The film comprising the thermoplastic resin composition according to the present invention has excellent gas impermeability and transparency, and can be applied to packaging films and the like in various fields such as food, agriculture and medical fields. .

Next, the present invention will be specifically described based on examples, but the present invention is not limited to these examples.
[1] Method for measuring average particle size by dynamic light scattering method A sample (fine particle dispersion) is diluted with 0.58% ammonia water to adjust the solid content concentration to 1% by mass. The average particle size was measured.

[Particle size measuring device]
Laser particle analyzer (manufactured by Otsuka Electronics Co., Ltd., laser particle size analysis system: LP-510 model PAR-III, measurement principle: dynamic light scattering method, measurement angle 90 °, photo detector 2 inch photomultiplier tube, measurement range 3 nm to 5 μm , Light source He-Ne laser 5mW 632.8nm, Temperature adjustment range 5 ~ 90 ℃, Temperature adjustment system Peltier element (cooling), Ceramic heater (heating), Cell
10mm square plastic cell, measurement object: colloidal particles)

[2] Measuring method of ratio of minor axis / major axis In a photographic projection view obtained by photographing a sample (fine particle dispersion) at a magnification of 250,000 times with a transmission electron microscope (H-800, manufactured by Hitachi, Ltd.) , For any 50 particles, the ratio (DS / DL) of the major axis (DL), which is the maximum diameter, and the minor axis (DS) orthogonal to the maximum diameter is measured, and the average value thereof is calculated as The major axis ratio was used.

[3] pH measurement For measuring the pH of silica sol, about 50 g of a sample for measurement was collected in a polyethylene sample bottle and immersed in a thermostatic bath at 25 ° C. for 30 minutes or more, and then a standard solution of pH 4, 7 and 9 The glass electrode of pH meter F22 manufactured by HORIBA, Ltd., for which correction was completed, was inserted and carried out.

[4] Measurement of Smectite-type Layered Particle Content Regarding the composition of the flaky composite silica fine particles, silica was dissolved by an alkali melting method, and the silica concentration was determined by a gravimetric method.

[5] Light transmittance measurement of film The light transmittance is measured with a spectrophotometer (U-vest 560 manufactured by JASCO Corporation) to measure the light transmittance at the absorption peak wavelength. The difference was taken as the light transmittance of the gas impermeable film.

[6] Oxygen permeability The gas permeability test was carried out by a differential pressure method based on Japanese Industrial Standard JIS K7126 "Plastic film and sheet gas permeability test method". It consists of a permeation cell for allowing gas to pass through the test piece, a pressure detector for measuring a pressure change due to the permeated gas, a gas supplier for supplying oxygen to the permeation cell, and a vacuum pump. The pressure detector was measured with an accuracy of 1 Pa using a NEW Palmyl vacuum gauge PVD-9500-L21 manufactured by Sato Vacuum Co., Ltd. The diameter of the transmission surface was 30 mm, and the test piece was dried for 48 hours or more using silica gel in a desiccator. The test conditions were a room temperature of 25 ° C. and a test temperature of 25 ° C. One (low pressure side) separated by the test piece was kept in vacuum, gas was introduced into the other (high pressure side) (about 1 atm), and the pressure on the low pressure side was recorded to obtain a transmission curve. Calculated pressure variation of the low pressure side of the unit from the slope of a steady state permeation curve time was calculated gas permeability ^{[ml / m 2 / 24hrs /} MPa].
In addition, oxygen was used for gas and the average value measured three places was used for the thickness of the test piece.

(Synthesis Example 1)
100 g of saponite [Na _0.33 (Mg ₃ ) (Al _0.33 Si _3.67 ) O ₁₀ (OH) ₂ .5H ₂ O, average particle diameter 20 nm (by dynamic light scattering method), minor axis / major axis ratio 0.3] Pure water and a 5% by weight aqueous solution of sodium hydroxide were added, and 10 kg of a saponite aqueous solution (solid content 1% by weight,
pH 11.0) was prepared.

This saponite aqueous solution was kept at 80 ° C., and 17.8 kg of a silicic acid solution (silica concentration: 4.5 mass%) was added at an addition rate of 59 g / min (in terms of silica). 80 hours after addition, 80 hours
After aging by holding at 0 ° C., the mixture was concentrated by a rotary evaporator to obtain a flaky composite silica fine particle dispersion having a solid content of 20% by mass. The details of the production conditions of this flaky composite silica fine particle dispersion are shown in Table 1, and the flaky composite silica fine particle dispersion and polishing characteristics are shown in Table 2.

(Synthesis Example 2)
The same saponite aqueous solution 10 kg (solid content 1 mass%, pH 11.0) as in Synthesis Example 1 was prepared.

This saponite aqueous solution was kept at 80 ° C., and 6 kg of a silicic acid solution (silica concentration: 4.5 mass%) was added at an addition rate of 59 g / min (silica conversion). After completion of the addition, the mixture was aged by holding at 80 ° C. for another hour, and then concentrated with a rotary evaporator to obtain a solid content of 2
A 0 mass% flaky composite silica fine particle dispersion was obtained. The details of the production conditions of this flaky composite silica fine particle dispersion are shown in Table 1, and the flaky composite silica fine particle dispersion and polishing characteristics are shown in Table 2.

(Synthesis Example 3)
The same saponite aqueous solution 10 kg (solid content 1 mass%, pH 11.0) as in Synthesis Example 1 was prepared.

This saponite aqueous solution was kept at 80 ° C., and 35.6 kg of a silicic acid solution (silica concentration: 4.5 mass%) was added at an addition rate of 59 g / min (silica conversion). 80 hours after addition, 80 hours
After aging by holding at ° C., the mixture was concentrated by a rotary evaporator to obtain a silica-based composite fine particle dispersion having a solid content of 20% by mass. Details of the production conditions of this silica-based composite fine particle dispersion are shown in Table 1, and silica-based composite fine particle dispersion and polishing characteristics are shown in Table 2.

Example 1
An aqueous polyvinyl acetate solution (solid content concentration 10% by mass) was added to the flaky composite silica fine particle dispersion (average particle size 30 nm, solid content concentration 20% by mass ) obtained by the production method of Synthesis Example 1 , and flaky composite silica fine particles and It added so that it might become the ratio shown in Table 3, and it shaked violently, and obtained the uniform dispersion liquid containing flaky composite silica fine particles and polyvinyl acetate. This dispersion was deaerated with a vacuum deaerator. Next, this dispersion was applied to a fluororesin tray having a flat surface. Using a spacer, this tray was dried in a forced air oven at 60 ° C. for 1 hour to obtain a uniform film having a thickness of about 10 μm. The film performance is shown in Table 3.

(Example 2)
An aqueous polyvinyl acetate solution (solid content concentration 10% by mass) was added to the flaky composite silica fine particle dispersion (average particle size 30 nm, solid content concentration 20% by mass ) obtained by the production method of Synthesis Example 1 , and flaky composite silica fine particles and It added so that it might become the ratio shown in Table 3, and it shaked violently, and obtained the uniform dispersion liquid containing flaky composite silica fine particles and polyvinyl acetate. This dispersion was deaerated with a vacuum deaerator. Next, this dispersion was applied to a fluororesin tray having a flat surface. Using a spacer, this tray was dried in a forced air oven at 60 ° C. for 1 hour to obtain a uniform film having a thickness of about 10 μm. The film performance is shown in Table 3.

(Example 3)
An aqueous polyvinyl acetate solution (solid content concentration 10% by mass) was added to the flaky composite silica fine particle dispersion (average particle size 22 nm, solid content concentration 20% by mass ) obtained by the production method of Synthesis Example 2, and the flaky composite silica fine particles and It added so that it might become the ratio shown in Table 3, and it shaked violently, and obtained the uniform dispersion liquid containing flaky composite silica fine particles and polyvinyl acetate. This dispersion was deaerated with a vacuum deaerator. Next, this dispersion was applied to a fluororesin tray having a flat surface. Using a spacer, this tray was dried in a forced air oven at 60 ° C. for 1 hour to obtain a uniform film having a thickness of about 10 μm. The film performance is shown in Table 3.

Example 4
An aqueous polyvinyl acetate solution (solid content concentration 10% by mass) was added to the flaky composite silica fine particle dispersion (average particle size 22 nm, solid content concentration 20% by mass ) obtained by the production method of Synthesis Example 2, and the flaky composite silica fine particles and It added so that it might become the ratio shown in Table 3, and it shaked violently, and obtained the uniform dispersion liquid containing flaky composite silica fine particles and polyvinyl acetate. This dispersion was deaerated with a vacuum deaerator. Next, this dispersion was applied to a fluororesin tray having a flat surface. Using a spacer, this tray was dried in a forced air oven at 60 ° C. for 1 hour to obtain a uniform film having a thickness of about 10 μm. The film performance is shown in Table 3.

(Comparative Example 1)
Silica composite particle dispersion obtained by the production method of Synthesis Example 3 (average particle diameter 37 nm, solid concentration 20 wt%) in the polyvinyl acetate solution (solid concentration 10 wt%), silica-based composite fine particles and polyvinyl acetate It added so that it might become a ratio shown in Table 3, and it shaked violently, and obtained the uniform dispersion liquid containing a silica type composite fine particle and polyvinyl acetate. This dispersion was deaerated with a vacuum deaerator. Next, this dispersion was applied to a fluororesin tray having a flat surface. Using a spacer, this tray was dried in a forced air oven at 60 ° C. for 1 hour to obtain a uniform film having a thickness of about 10 μm. The film performance is shown in Table 3.

(Comparative Example 2)
20 masses of saponite [Na _0.33 (Mg ₃ ) (Al _0.33 Si _3.67 ) O ₁₀ (OH) ₂ .5H ₂ O, average particle diameter 20 nm (by dynamic light scattering method), minor axis / major axis ratio 0.3] 100 g of an aqueous polyvinyl acetate solution (solid content concentration: 10% by mass) was added to 500 g of 100% aqueous solution and shaken vigorously to obtain a uniform dispersion containing flaky composite silica fine particles and polyvinyl acetate. This dispersion was deaerated with a vacuum deaerator. Next, this dispersion was applied to a fluororesin tray having a flat surface. Using a spacer, this tray was dried in a forced air oven at 60 ° C. for 1 hour to obtain a uniform film having a thickness of about 10 μm. The film performance is shown in Table 3.

Claims (6)

  100 parts by weight of a thermoplastic resin and an average particle diameter measured by a dynamic light scattering method are in the range of 10 to 100 nm, the short diameter / long diameter ratio is in the range of 0.01 to 0.7, and 25 smectite-type layered fine particles are used. A thermoplastic resin composition comprising 5 to 60 parts by weight of flaky composite silica fine particles containing ~ 90% by mass.   The thermoplastic resin composition according to claim 1, wherein the flaky composite silica fine particles are formed by forming a silica layer on the surface of smectite-type layered fine particles.   2. The thermoplastic resin composition according to claim 1, wherein the flaky composite silica fine particles are those obtained by growing particles with a silica component using smectite-type layered fine particles as core particles. The thermoplastic according to any one of claims 1 to 3, wherein the smectite-type layered fine particles are composed of any one of the trioctahedral smectites shown in the following (1) to (5). Resin composition.
(1) Saponite [X _0.33 (Mg ₃ ) (Al _0.33 Si _3.67 ) O ₁₀ (OH) ₂ .nH ₂ O],
(2) Iron saponite _{[X 0.33 (Mg, Fe)} 3 (Al 0.33 Si 3.67) O 10 (OH) 2 · nH 2 O],
(3) Hectorite [X _0.33 (Mg _2.67 Li _0.33 ) Si ₄ O ₁₀ (OH) ₂ .nH ₂ O],
(4) sauconite _{[X 0.33 (Mg, Zn)} 3 (Si 3.67 Al 0.33) O 10 · nH 2 O],
(5) Steven site [X _{0.33 / 2} (Mg _2.97 ) Si ₄ O ₁₀ (OH) ₂ · nH ₂ O]
(However, X is K, Na, 1 / 2Ca or 1 / 2Mg. N is n ≧ 0.)   The heat according to any one of claims 1 to 4, wherein the thermoplastic resin is selected from polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl acetate resin, polyethylene resin or polyethylene terephthalate resin. Plastic resin composition. The film which consists of a thermoplastic resin composition of any one of Claims 1-5 .