JPH115886A - Polyoxymethylene resin composition improved in mechanical physical property - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition improved in mechanical physical properties represented by flexural modulus by using a laminar clay mineral material improved in affinity for the polyoxymethylene resin as a reinforcing material and finely grinding the reinforcing material. SOLUTION: This polyoxymethylene resin composition comprises (A) 100 pts.wt. of a polyoxymethylene resin comprising oxymethylene homopolymer or an oxymethylene copolymer, and (B) 0.01-100 pts.wt. of a laminar clay mineral material dispersible in organic solvents. The laminar clay mineral material is produced by allowing 100 pts.wt. of a laminar clay mineral having a cation exchange capacity of 50-200 milliequivalent/100 g to adsorb 5-500 pts.wt. of a lipophilic agent. The cleaved particles having sizes of <=5 μm and preferably having thicknesses of <=50 nm in the direction of their laminates in the component B are homogeneously dispersed in an average inter-particle distance of <=10 μm. The laminar clay mineral includes a smectite mineral and swelling fluoride mica.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a polyoxymethylene resin composition comprising a polyoxymethylene resin and a layered clay mineral material, which is lightweight and has improved mechanical properties.

[0002]

2. Description of the Related Art Polyoxymethylene resins have a wide range of industrial uses, and utilize their excellent strength characteristics, fatigue resistance, self-lubricating properties, heat resistance, etc., and are used in automobiles, electric products, mechanical parts, etc. Used in the field. By the way, in applications requiring mechanical properties typified by higher flexural modulus, polyoxymethylene resin is blended with a large amount of a reinforcing agent such as glass fiber and carbon fiber to improve the flexural modulus. . However, when these reinforcing agents are blended in a large amount, there are problems such as poor slidability.

[0003]

DISCLOSURE OF THE INVENTION The present invention relates to a polyoxymethylene resin having improved mechanical properties typified by flexural modulus at the same time while maintaining excellent inherent properties such as slidability of a polyoxymethylene resin. It is intended to obtain a methylene resin composition.

[0004]

Means for Solving the Problems As a result of intensive studies, the present inventors have used a layered clay mineral material having an improved affinity for a polyoxymethylene resin as a reinforcing agent, and used a finely divided layer of the reinforcing agent. Thus, the present inventors have found that a polyoxymethylene resin composition obtained with a relatively small amount of compound has excellent performance and can effectively solve the above-mentioned problems, and completed the present invention.

That is, the present invention provides: The polyoxymethylene resin is composed of 100 parts by weight and an organic solvent-dispersible layered clay mineral material of 0.01 to 100 parts by weight, and the average distance between particles of 5 μm or less in the layered clay mineral material is 10 μm or less. 1. a polyoxymethylene resin composition characterized by being uniformly dispersed; The organic solvent dispersible layered clay mineral material has a thickness of 5 μm or less, and has a thickness in the laminating direction of 50 nm or less. 2. the polyoxymethylene resin composition of the above 1; The polyoxymethylene resin composition according to the above 1 or 2, wherein the layered clay mineral material dispersible in an organic solvent is a swellable fluorinated mica-based mineral or a smectite-based mineral adsorbing a lipophilic agent. . 4. A molded article for an electric / electronic part obtained by molding the polyoxymethylene resin composition of the above 1, 2 or 3. 5. A molded product for a mechanical part obtained by molding the polyoxymethylene resin composition of the above 1, 2 or 3. It is intended to provide a molded article for automobile parts obtained by molding the polyoxymethylene resin composition of the above 1, 2 or 3.

Hereinafter, the present invention will be described in more detail. The polyoxymethylene resin targeted in the present invention may be an oxymethylene homopolymer or an oxymethylene copolymer. The oxymethylene homopolymer is substantially an oxymethylene unit — (CH) obtained by polymerizing a cyclic oligomer such as formaldehyde or its trimer (trioxane) or tetramer (tetraoxane).
₂ O)-. On the other hand, the oxymethylene copolymer is a polymer having a structure in which oxyalkylene units are randomly introduced into a chain composed of oxymethylene units, and the content of the oxyalkylene unit in the oxymethylene copolymer is , Per 100 mol of oxymethylene unit, preferably 0.01 to 1.0 mol, more preferably 0.01 to 0.8 mol. Examples of the oxyalkylene unit include an oxyethylene unit, a linear or branched oxypropylene unit, a linear or branched oxybutylene unit, an oxyphenylethylene unit, and the like. Or two or more kinds may be introduced. Among these oxyalkylene units, oxyethylene units, linear oxypropylene units, and linear oxybutylene units are particularly preferable from the viewpoint of improving the physical properties of the polyoxymethylene resin. The oxymethylene copolymer is formed by copolymerizing formaldehyde or a formaldehyde cyclic oligomer such as trioxane or tetraoxane with a cyclic ether such as ethylene oxide, propylene oxide, epichlorohydrin, 1,3-dioxolan, formal of glycol, or formal of diglycol. It can be obtained by: In the present invention, one kind of the above polyoxymethylene resin may be used, or two or more kinds may be used in combination.

In the present invention, an organic solvent-dispersible layered clay mineral material is defined as 5 to 200 parts by weight of a layered clay mineral having a cation exchange capacity of 50 to 200 meq / 100 g.
500 parts by weight, preferably 20 to 200 parts by weight of the lipophilic agent is adsorbed. The layered clay mineral used in the present invention is a layered clay mineral having a cation exchange capacity of 50 to 200 meq / 100 g. Here, the cation exchange capacity was set to 50 to 200 meq / 100 g when the capacity exceeded 200 meq / 100 g.
This is because the bonding strength between the layers of the mineral is so strong that it is difficult to disperse it at the molecular level. On the other hand, if it is less than 50 meq / 100 g, the lipophilic agent cannot be sufficiently exchanged and adsorbed. This is because it becomes difficult to obtain a solvent-dispersible layered clay mineral material.

Specific examples of the layered clay mineral used in the present invention include smectite-based minerals such as montmorillonite, saponite, beidellite, nontronite, hectorite, stevensite, permiculite, halloysite, and swellable fluorinated mica. And the like, and may be natural or synthetic. These layered clay minerals are composed of a layered silicate, and the layered silicate is a layered phyllosilicate formed of a magnesium silicate or aluminum silicate layer having a layer thickness of 7 to 12 angstroms. These layered silicates are negatively charged due to isomorphous ion substitution or the like. Although the characteristics vary depending on the density and distribution of the negative charge, in the present invention, it is preferable that the layer silicate has an area occupied by 25 to 200 square angstroms of the layer surface per negative charge. In particular, swellable fluorinated mica, smectite-based mineral, or a mixture thereof is preferably used as a raw material of the organic solvent-dispersible layered clay mineral material of the present invention. Preferably, the layered clay mineral is pulverized by using a mixer, a ball mill, a vibration mill, a pin mill, a jet mill, a beating machine, or the like to obtain a desired shape and size in advance. The preferred size of the layered clay mineral used in the present invention is 5 μm or less on one side and 0.5 μm or less in thickness.

The organic solvent-dispersible layered clay mineral material of the present invention is obtained by adsorbing an organic cation of a lipophilic agent between layers of the layered clay mineral. The lipophilic agent exchanged and adsorbed between the layers of the layered clay mineral has a role of expanding the clay layer and a role of improving the affinity with the solvent and the resin material. 50 nm
It is presumed that the following fine particles could be generated and the dispersibility of the layered clay mineral as a reinforcing agent could be improved, and as a result, a polyoxymethylene resin composition having improved mechanical properties could be provided.

The lipophilic agent that imparts solvent dispersibility and / or affinity to a resin material to the layered clay mineral includes the following: (1) an ammonium ion group, a phosphonium ion group, a sulfonium ion, which can be exchange-adsorbed between layers of the layered clay mineral. An onium ion group such as an ionic group, and (2) a functional group having an effect of expanding between clay layers (linear saturated aliphatic compound group, linear unsaturated aliphatic compound group, branched aliphatic compound group, hydroxypolyoxyalkylene group) Etc.), a functional group (a vinyl group, a carboxyl group, a hydroxyl group, an epoxy group, an amino group, etc.) having an effect of giving thermoplasticity to a layered clay mineral material and an effect of improving affinity with a solvent or a resin material. Functional group), and one or more of them are used.

In the present invention, an ammonium ion onium compound containing one or more linear aliphatic compound groups or hydroxypolyoxyalkylene groups represented by the following general formula is preferably used.

[0012]

Embedded image

(Wherein R ₁ is a functional group selected from H, CH ₃ and C ₂ H ₅ , and R ₂ , R ₃ and R ₄ are H, CH
₃ , C ₂ H ₅ , a linear saturated aliphatic compound group having 3 to 18 carbon atoms, a linear unsaturated aliphatic compound group having 3 to 18 carbon atoms, a branched aliphatic compound group having 3 to 18 carbon atoms, degree of polymerization Functional groups independently selected from 1 to 12 hydroxypolyoxyalkylene groups, which may be the same or different. X ^- is a chloride ion or the like, and is washed and removed after the lipophilic agent is exchange-adsorbed to the layered clay mineral. The organic solvent dispersible layered clay mineral material used in the present invention is one in which 5 to 500 parts by weight, preferably 20 to 200 parts by weight of the lipophilic agent is adsorbed per 100 parts by weight of the layered clay mineral. In the present invention, the lipophilic agent was removed by thermally decomposing the organic solvent-dispersible layered clay mineral material using a thermobalance, and the amount of the adsorbed lipophilic agent was determined from the weight loss. If the oleophilic agent is less than 5 parts by weight, the dispersibility of the organic solvent-dispersible layered clay mineral material is insufficient, and if it exceeds 500 parts by weight, the effect of improving the mechanical properties deteriorates, which is not preferable.

The method for producing a layered clay mineral material dispersible in an organic solvent achieves the object of forming a complex by infiltration and exchange adsorption of a lipophilic agent between clay layers of swellable fluorinated mica, smectite mineral or the like. The method is not particularly limited as long as it is performed, but as a typical method, first, a swellable fluorinated mica, a smectite-based mineral, or the like is dispersed in water to prepare a suspension. If necessary, this suspension is classified and impurities are removed, and then a lipophilic agent having a cation exchange capacity equal to or more than the cation exchange capacity of the layered clay mineral material is added to carry out exchange adsorption reaction. The reaction itself proceeds promptly and the product precipitates immediately, but is further stirred for 30 minutes or more in the reaction solution. At this time, a method of heating the reaction solution from room temperature to about 80 ° C. or applying ultrasonic vibration is also preferably used. The product is sufficiently washed with water and then subjected to suction filtration using a Buchner funnel to obtain a hydrated composite. Dry this,
By pulverizing, the desired organic solvent dispersible layered clay mineral material is obtained.

The amount of the organic solvent-dispersible layered clay mineral material in the polyoxymethylene resin composition of the present invention is as follows:
0.01 to 100 parts by weight of polyoxymethylene resin
To 100 parts by weight, preferably 0.1 to 50 parts by weight, more preferably 0.5 to 10 parts by weight. If the amount is less than 0.01 part by weight, the effect of improving mechanical properties is insufficient.
If the amount exceeds 0 parts by weight, the decrease in toughness increases.

In the method for producing the polyoxymethylene resin composition of the present invention, a polyoxymethylene resin and an organic solvent-dispersible layered clay mineral material are dissolved and mixed in a common solvent, and then the solvent is distilled off to form a composite. A method in which a polyoxymethylene resin and a layered clay mineral material dispersible in an organic solvent are heated and dissolved in a common solvent and mixed, and then the polyoxymethylene resin and the layered clay mineral material are simultaneously precipitated and precipitated to form a composite. A method of polymerizing a monomer in a state where a predetermined amount of a layered clay mineral material dispersible in a solvent with respect to a monomer forming a polyoxymethylene resin is used. A method of forming a composite by melt-kneading a resin and a layered clay mineral material dispersible in a solvent may be used. The most preferred method of producing the polyoxymethylene resin composition of the present invention is melt kneading using a twin-screw extruder in order to enhance cleavage of the clay layer of the organic solvent dispersible layered clay mineral material and improve dispersion. This is a method of compounding. The solvent may be any solvent that can dissolve both the polyoxymethylene resin and the layered clay mineral material dispersible in an organic solvent, and usually, dimethylformamide, dimethylacetamide, N
-Methylpyrrolidone, hexafluoroisopropanol and the like are used.

The present invention is a polyoxymethylene resin composition containing fine particles having a thickness in the laminating direction of 50 nm or less formed by cleavage of a clay layer and having improved dispersibility of clay fine particles. The resulting thickness in the stacking direction is 50n
The dispersion state of the fine particles having a particle diameter of not more than m and the fine particles having a dispersed particle diameter of not more than 5 μm can be evaluated by collecting a thin section of a molded article of the resin composition and analyzing the thin section using a transmission electron microscope. The length of the long side of the plane image of the independently dispersed clay fine particles observed in the transmission electron micrograph of the flake was defined as the dispersed particle diameter.
The distance between the centers of gravity of the plane images of the clay fine particles was defined as the distance between the dispersed particles.

According to the present invention, fine particles of 5 μm or less in an organic solvent-dispersible layered clay mineral material have an average distance between particles of 10 μm.
It is a polyoxymethylene resin composition uniformly dispersed with a particle size of not more than μm. The dispersibility of the layered clay mineral can be controlled by the design of the organic solvent dispersible layered clay mineral material, the conditions for forming a composite with the polyoxymethylene resin, and the like. In the present invention, the method for obtaining the average particle diameter of the fine particles of 5 μm or less and the average distance between the fine particles was performed by the method described in the embodiment of the present invention. Further, in the present invention, it is assumed that the particles are uniformly dispersed if the average distance between the fine particles of 5 μm or less at the measurement points described in the embodiment of the invention is 10 μm or less at any measurement point.

If the fine particles having a dispersed particle size of 5 μm or less cannot be uniformly dispersed with each other at an average distance between particles of 10 μm or less, the affinity between the polyoxymethylene resin and the particles of the layered clay mineral material dispersible in an organic solvent is reduced. It is considered that sex is lacking. In this case, since the particles of the layered clay mineral material dispersible in the organic solvent are aggregated, the effect of improving the mechanical properties is small. Even if fine particles having a dispersed particle size of 5 μm or less are present, the effect of improving the mechanical properties is still small when the average distance between the fine particles exceeds 10 μm due to the small amount of the fine particles. Since the polyoxymethylene resin composition of the present invention has a greater effect of improving the mechanical properties as the dispersed particle size of clay fine particles and the distance between the fine particles are smaller, the fine particles having a dispersed particle size of 5 μm or less are preferably formed with an average interparticle distance of 5 μm or less. That they are evenly distributed,
More preferably, the fine particles having a dispersed particle size of 2 μm or less are uniformly dispersed with an average interparticle distance of 5 μm or less, and particularly preferably the fine particles having a dispersed particle size of 1 μm or less and 1 nm or more have an average interparticle distance of 2 μm or less and 20 nm or more. That is, they are uniformly dispersed.

The organic solvent-dispersible layered clay mineral compound incorporated in the present invention is preferably cleaved into fine particles having a thickness in the lamination direction of 50 nm or less, more preferably 30 nm or less. The thickness in the laminating direction is preferably small, and most preferably cleaved to 1 nm, which is the thickness of one layer. The average distance between the fine particles is preferably 10 μm or less by increasing the ratio of the fine particles having a thickness in the laminating direction of 50 nm or less, and more preferably 5 μm or less and the mechanical properties are further improved by 20 nm or more. Is done. The proportion of the fine particles can be controlled by the design of the solvent-dispersible layered clay mineral material and the conditions for forming a composite with the polyoxymethylene resin. The fine particles having a thickness of 50 nm or less in the laminating direction correspond to those which appear thin in a transmission electron micrograph.

The polyoxymethylene resin composition of the present invention contains various stabilizers such as a heat stabilizer, an antioxidant and a weathering agent, as well as dyes, pigments, flame retardants and the like, as long as the object of the present invention is not largely impaired. It is possible to mix a moldability improving agent such as a plasticizer, a release agent, and other reinforcing agents, and to knead the mixture at the time of molding and before molding. Further, if necessary, another polymer, a multi-layered interpolymer or the like can be blended in the resin composition of the present invention.

The polyoxymethylene resin composition of the present invention can be used to produce a desired molded article by a usual molding method. For example, a thin film can be formed by a casting method of a thermoplastic resin such as injection molding, extrusion molding, or blow molding, or a casting method from an organic solvent solution. The resin composition of the present invention has a polyoxymethylene resin originally because the effect of improving the mechanical properties with respect to the compounding amount is remarkable as compared with the composition using another reinforcing agent, sliding property, chemical resistance, Lightweight molded products with improved mechanical properties can be obtained while maintaining excellent properties such as fatigue resistance, so mechanical parts and housings such as switches, connectors and pins in electrical and electronic equipment and gears in machinery. It can be particularly suitably used for exterior and interior parts in the field of automobile parts, such as bearings, bearings, cams and rollers.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described specifically with reference to examples. In addition, each characteristic of the polyoxymethylene resin composition was determined as follows. (1) Flexural modulus According to ASTM D-790, cylinder temperature 20
Using a molding machine set at 0 ° C. and a mold at 70 ° C., a bending test piece of the polyoxymethylene resin composition was prepared with a cooling time of 30 seconds, and then the bending elastic modulus was evaluated. (2) Dispersion state of particles of layered clay mineral material dispersible in organic solvent Using an ultramicrotome, three cross sections of the bending test piece of the polyoxymethylene resin composition (center part, surface part, middle part between center and surface) From one piece 0.5mm thickness 90nm
Slices were collected. Using a transmission electron microscope (JEM-100SX, JEOL Ltd.), this was applied to one place at a magnification of 1,000 times (60 μm × 80 μm) and 30,000 times (2 μm × 2.7 μm) depending on the particle size to be measured. The slices were photographed at any three sites. The length of the long side of the plane image of the independently dispersed clay fine particles observed in the transmission electron micrograph of the flake was defined as the dispersed particle diameter. The distance between the centers of gravity of the planar images of the clay fine particles was defined as the distance between dispersed particles. The thickness in the stacking direction caused by cleavage of the clay layer is 50n
Similarly, the distance between the centers of gravity of the planar images of the fine particles having a thickness of 50 nm or less is defined as the distance between the fine particles having a thickness in the stacking direction of 50 nm or less. The average dispersed particle diameter (D) is obtained by dividing a photograph into four equal parts, arbitrarily selecting one particle of 5 μm or less from each part, measuring the particle diameter, and calculating the average of 4 × 3 × 3 particles of the entire test piece. Was. The average distance between particles (L1) was calculated by dividing the photograph into four equal parts, and
m is arbitrarily selected, and the distance to the nearest particle of 5 μm or less is measured in four directions (up and down and left and right) around the particle, an average value thereof is obtained, and 4 × of the entire test piece is obtained. An average of 3 × 3 pieces was obtained. The same procedure was applied to fine particles having a thickness in the stacking direction of 50 nm or less generated by cleavage of the clay layer, and the average distance between the fine particles (L2) was obtained. If the average interparticle distance was 4 μm or less at 4 × 3 × 3 measurement points on the entire test piece, it was determined that the particles were uniformly dispersed. The proportion of the fine particles having a particle size of 5 μm or less was determined by the following equation based on the area of the planar image of the particles (S = 100 × (the sum of the areas of the fine particles having a particle size of 5 μm or less).
/ (Sum of areas of planar images of all viscosity particles)) (3) Sliding characteristics Friction and wear tester (AFT-15, manufactured by Tosoh Seimitsu Kogyo Co., Ltd.)
MS), surface pressure 10 kg / cm ² , linear velocity 60 cm /
Secondly, the measurement was performed without lubrication of the mating material S45C, and the mating surface condition was evaluated. At this time, the case where the surface of the partner material was severely scratched was evaluated as x, the case where the surface was slightly scratched was evaluated as 場合, and the case where the partner material did not change was evaluated as ○. The following materials were used as the polyoxymethylene resin and the solvent-dispersible layered clay mineral material. (1) POM1: oxymethylene homopolymer Melt index 9.9 g / 10 min [ASTM D-
1238-57T (E condition)], a formaldehyde polymer whose terminal is stabilized by a methoxy group and an acetyl group. (2) POM2: oxymethylene copolymer Melt index of 9.0 g / 10 min obtained by copolymerizing trioxane and ethylene oxide and introducing 1.6 mol of ethylene oxide as a comonomer component per 100 mol of oxymethylene unit [ ASTM D-1238
-57T (E condition)]. (3) POM3: oxymethylene copolymer 9.0 g of ethylene oxide, a comonomer component, obtained by copolymerizing trioxane and 1,3-dioxolane, into which 1.6 moles were introduced per 100 moles of oxymethylene units. / 10 min [ASTM D-1
238-57T (E condition)]. (4) CLAY1: Swellable fluorinated mica (hydrophilic) Swellable fluorinated mica (Somasif ME-100 manufactured by Corp Chemical Co., Ltd.) (cation exchange capacity = 75 meq / 1)
00g). (5) CLAY2: Organic solvent dispersible swellable fluorinated mica (lipophilic) 500 g of swellable fluorinated mica (Somasif ME-100 manufactured by Corp Chemical Co., Ltd.) is dispersed in 5 L of pure water,
Add dioctadecyl dimethyl ammonium chloride 500
The product lipophilized and precipitated by adding g was collected by filtration and washed repeatedly with water. This was dried and pulverized and used for producing a polyoxymethylene resin composition. CLAY
By thermally decomposing 2 with TGA to remove the lipophilic agent,
When the ratio of the layered clay mineral material in CLAY2 was determined, it was 60 wt%. (6) CLAY3: Organic solvent dispersible swellable fluorinated mica (lipophilic) 500 g of swellable fluorinated mica (Somasif ME-100, manufactured by Corp Chemical Co., Ltd.) is dispersed in 5 L of pure water,
To this was added 500 g of trioctylmethylammonium chloride, and the lipophilic and precipitated product was collected by filtration and washed repeatedly with water. This was dried and pulverized and used for producing a polyoxymethylene resin composition. CLAY3 is thermally decomposed with TGA to remove the lipophilic agent, thereby obtaining CL.
When the ratio of the layered clay mineral material in AY3 was determined,
It was 0 wt%. (7) CLAY4: Solvent-dispersible synthetic smectite (lipophilic) Synthetic smectite (SWN manufactured by Corp Chemical Co., Ltd.)
(Cation exchange capacity = 101 meq / 100g) 50
0 g was dispersed in 5 L of pure water, and 500 g of trioctylmethylammonium chloride was added thereto, and the product which was made lipophilic and precipitated was collected by filtration and washed repeatedly with water. The product was dried and pulverized and used for producing a polyoxymethylene resin composition. CLAY4 was thermally decomposed with TGA to remove the lipophilic agent, and the ratio of the layered clay mineral material in CLAY4 was determined to be 68 wt%.

[0024]

Examples 1 to 8 As shown in Table 1, a twin-screw extruder heated to 200 ° C. after dry-blending various polyoxymethylene resins and an organic solvent-dispersible layered clay mineral material at a predetermined ratio. And melt-kneaded into pellets. This was subjected to molding and evaluation of flexural modulus according to ASTM D-790 as described above. In addition, the slidability was evaluated by the method described above. Further, the diameter of the dispersed particles and the distance between the dispersed particles were evaluated using a transmission electron microscope. In Examples 1 to 8, all were uniformly dispersed.

[0025]

Comparative Examples 1 to 6 As shown in Table 1, various polyoxymethylene resins alone or a layered clay mineral material were dry-blended at a predetermined ratio and then heated to 200 ° C. using a twin-screw extruder. It was melt-kneaded and pelletized. This was subjected to molding and evaluation of flexural modulus according to ASTM D-790 as described above. In addition, the slidability was evaluated by the method described above. Further, the diameter of the dispersed particles and the distance between the dispersed particles were evaluated using a transmission electron microscope.

[0026]

[Table 1]

[0027]

The polyoxymethylene resin composition of the present invention improves the affinity between the polyoxymethylene resin and the toughening agent and makes the dispersion of the toughening agent finer, so that the mechanical properties as compared with the compounding amount are improved. A polyoxymethylene resin composition having improved mechanical properties typified by flexural modulus without impairing the inherently excellent sliding property of the polyoxymethylene resin which has been significantly improved.

[Brief description of the drawings]

FIG. 1 is a transmission electron micrograph of Example 8 which was stretched twice at 5,000 times magnification and developed.

FIG. 2 is a transmission electron micrograph of Comparative Example 4 which was stretched twice at 5,000 times magnification and developed. In Comparative Example 4, extremely small particles were selected and photographed. The blending amount is the same as that in FIG. 1, but there is no neighboring particle over several tens μm around the particle.

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[Procedure amendment]

[Submission date] June 27, 1997

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

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[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

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Claims (6)

[Claims] 1. An average particle size of 100 parts by weight of a polyoxymethylene resin and 0.01 to 100 parts by weight of an organic solvent-dispersible layered clay mineral material, wherein the average particle size of fine particles of 5 μm or less in the layered clay mineral material is reduced. A polyoxymethylene resin composition having a distance of 10 μm or less and being uniformly dispersed. 2. An organic solvent dispersible layered clay mineral material having a thickness of 5 μm or less and having a thickness of 50 nm or less in the laminating direction and having an average interparticle distance of 10 μm or less, which is uniformly dispersed. The polyoxymethylene resin composition according to claim 1, wherein: 3. The organic solvent-dispersible layered clay mineral material comprises:
3. A swellable fluorinated mica-based mineral or a smectite-based mineral to which a lipophilic agent is adsorbed.
The polyoxymethylene resin composition according to the above. 4. A molded article for an electric / electronic part obtained by molding the polyoxymethylene resin composition according to claim 1, 2 or 3. 5. A molded article for a mechanical part obtained by molding the polyoxymethylene resin composition according to claim 1, 2 or 3. 6. A molded article for an automobile part obtained by molding the polyoxymethylene resin composition according to claim 1, 2 or 3.