JP2000290467A - Polyacetal resin composition and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyacetal resin composition capable of preventing warp without impairing outer appearance and improved in flexural property. SOLUTION: This polyacetal resin composition comprises polyacetal resin and a silane-clay composite material. The silane-clay composite material is prepared by including in an expansive silicate a silane-based compound expressed by the general formula YnSiX4-n [wherein, (n) is an integer of 0-3; Ys are each an organic functional group consisting of a (substituted) 1-25C hydrocarbon group; Xs are each a hydrolyzable group and/or hydroxyl group] and exists in a state that the average layer thickness is <=500 Å in the polyacetal resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a polyacetal resin composition containing a polyacetal resin and a silane clay composite, and a method for producing the resin composition.

[0002]

2. Description of the Related Art Polyacetal resins are excellent in strength, rigidity, heat resistance, impact resistance, fatigue resistance, and deterioration resistance, and are used for electric / electronic, automobile / transportation equipment, precision machinery, building materials, etc.
Widely used in various fields. Since the polyacetal resin is a highly crystalline resin, it has a large shrinkage during solidification. Therefore, sinking and warping are likely to occur in a thick portion or an uneven thickness portion of a molded product, which is a problem in product design, and improvement is required. In order to solve the above problems, the blending of an inorganic filler has been mainly performed. By blending inorganic filler,
Sinks and warpages are certainly improved, but not enough. In addition, problems such as impairment of the surface appearance and an increase in specific gravity due to the incorporation of a large amount of inorganic filler have also occurred. It is generally considered that such a defect in the blending of the inorganic filler is caused by poor dispersion of the inorganic filler or an excessively large size of the dispersed particles.

[0003] Techniques for finely dispersing inorganic fillers include:
(1) An organic metal compound such as a silane-based compound is bonded, and the average layer thickness is about 50 ° or less and the maximum layer thickness is about 100 °.
Invention relating to a resin composite material containing the following layered particles and a resin matrix (WO 95/06090)
Pamphlet (1995), US Patent 5,514,734
No., WO 93/04118 pamphlet (199
3), WO 93/11190 pamphlet (19)
93)), (2) Invention relating to a resin composition in which a layered silicate is dispersed as crystalline nuclei at a molecular level at an aspect ratio of 20 or more in a crystalline thermoplastic resin (JP-A-9-1839).
No. 10), (3) An average layer thickness of 25 in the thermoplastic resin
An invention relating to a resin composition in which a layered silicate having an aspect ratio of 20 to 300 at 1000 ° is dispersed (Japanese Patent Application Laid-Open No. 9-124836) is disclosed.

In the invention of the above (1), the tensile modulus of the nylon 6-based composite material comprising montmorillonite and nylon 6 bonded with isocyanatopropyltriethoxysilane and the like in which caprolactam is copolymerized is improved as compared with nylon 6 alone. It has been done, but it is not enough. Further, although a nylon 6-based composite material is disclosed, it is difficult to obtain a polyacetal resin composite material in which layered particles are finely dispersed by directly applying a nylon 6-based method to a polyacetal resin. Also,
In the techniques (2) and (3), swellable mica is used as a layered silicate, and swellable mica swelled with water or alkylammonium-treated swellable mica swelled with xylene is mixed with polybutylene terephthalate or the like. A technique of a resin composition obtained by screw extrusion is disclosed. However,
Even if the above technique is directly applied to the polyacetal resin, it is possible to obtain a polyacetal resin composition having desired physical properties because the layered silicate is incomplete and uneven even though it is partially finely dispersed. Can not.

[0005]

Accordingly, the layered silicate layer is cleaved and uniformly dispersed in a polyacetal resin in the form of a small thin plate, so that warpage, sinking and bending characteristics can be achieved without impairing the surface appearance or specific gravity. At present, there has not been provided a technique for obtaining a polyacetal resin composition having a sufficiently improved polyacetal resin composition, and an object of the present invention is to solve such conventional problems.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventors have separated and cleaved unit layers of swellable silicate,
The above-mentioned object is achieved by containing, in a polyacetal resin, a sheet-like silane clay composite prepared by subdividing one swellable silicate aggregated particle into a very large number of extremely fine sheet-like particles. They have found that this can be achieved, and have completed the present invention.

That is, a first aspect of the present invention is a polyacetal resin composition containing a polyacetal resin and a silane clay composite, wherein the silane clay composite is converted into a swellable silicate by the following general formula (1): Y _n SiX _4-n (1) (where n is an integer of 0 to 3 and Y is 1 to 3 carbon atoms)
X is a hydrolyzable group and / or a hydroxyl group, which is an organic functional group composed of 25 hydrocarbon groups and a hydrocarbon group having 1 to 25 carbon atoms and a substituent. n Y and 4-n X may be the same or different. The present invention relates to a polyacetal resin composition prepared by introducing a silane compound represented by the formula (1), wherein the average layer thickness of the silane clay composite in the resin composition is 500 ° or less.

[0008] In a preferred embodiment, the present invention relates to the above polyacetal resin composition, wherein the maximum thickness of the silane clay composite is 2000 ° or less.

In a further preferred embodiment, the [N] value is 30 or more, wherein the [N] value is present in an area of 100 μm ² of the resin composition and the particles per unit ratio of the silane clay composite. It relates to a polyacetal resin composition as defined above, defined as being a number.

In a further preferred embodiment, the silane clay composite has an average aspect ratio (ratio of layer length / layer thickness) of 1%.
It relates to the polyacetal resin composition as described above, which is 0 to 300.

A second aspect of the present invention is a polyacetal resin composition containing a polyacetal resin and a silane clay composite, wherein the silane clay composite is converted into a swellable silicate by the following general formula (1): Y _n SiX _{4− n} (1) (where n is an integer of 0 to 3 and Y is 1 to 3 carbon atoms)
X is a hydrolyzable group and / or a hydroxyl group, which is an organic functional group composed of 25 hydrocarbon groups and a hydrocarbon group having 1 to 25 carbon atoms and a substituent. n Y and 4-n X may be the same or different. ) Is prepared by introducing a silane compound represented by the formula (1), and the resin composition has an average aspect ratio (ratio of layer length / layer thickness) of 10 to 300, and [ N] value is 30 or more, wherein the [N] value is defined as the number of particles per unit ratio of the silane clay complex present in an area of 100 μm ^{2 of the} resin composition. About things.

A third aspect of the present invention is (A) a step of preparing a silane clay composite, (B) a step of mixing the polymerizable monomer of the polyacetal resin with the silane clay composite, and (C) polymerizing the polymerizable monomer. The present invention relates to a method for producing a polyacetal resin composition as described above, comprising the steps of:

In a preferred embodiment, step (B)
In the polyacetal resin composition according to the above, wherein the bottom spacing of the silane clay composite after being mixed with the polymerizable monomer of the polyacetal resin is at least three times the bottom spacing of the swellable silicate. It relates to a manufacturing method.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The polyacetal resin used in the present invention is a conventionally known polymer compound having an oxymethylene group (—CH ₂ O—) as a main component, and is a polyoxymethylene homopolymer or An oxymethylene group is a main repeating unit, and other structural units such as ethylene oxide, 1,3-dioxolan, 1,
Copolymers containing a comonomer unit such as 4-butanediol are exemplified. From the viewpoint of mechanical properties, the polyoxymethylene homopolymer and / or the polymer mainly composed of oxymethylene contain 0.1 to 4.0% of oxyalkylene units having 2 or more carbon atoms. Copolymers are preferred. Further, the polyacetal resin used in the present invention,
Some or all of the polyacetal resin may be a terpolymer or block polymer as long as the desired properties are not impaired. Further, a known modified polyacetal resin into which another organic functional group is introduced may be used.

[0015] The degree of polymerization of the polyacetal resin used in the present invention is not particularly limited as long as it has melt moldability, but the polyacetal resin is used at 190 ° C in accordance with ASTM D1238-89E.
The melt index measured in 1 to 50 g / 10 minutes,
More preferably, it is a thing of 5-35 g / 10 minutes.

The silane clay composite used in the present invention refers to a swellable silicate represented by the following general formula (1): Y _n SiX _4-n (1) (where n is an integer of 0 to 3; Has 1 to 1 carbon atoms
X is a hydrolyzable group and / or a hydroxyl group, which is an organic functional group composed of 25 hydrocarbon groups and a hydrocarbon group having 1 to 25 carbon atoms and a substituent. n Y and 4-n X may be the same or different. ) Is introduced.

The above-mentioned swellable silicate is mainly composed of a tetrahedral sheet of silicon oxide and an octahedral sheet of metal hydroxide. Examples of the swellable silicate include smectite group clay and swellable mica. Can be When using smectite group clay and swellable mica as the swellable silicate, the dispersibility of the swellable silicate in the polyacetal resin composition of the present invention, the availability and improvement of the physical properties of the resin composition. Preferred from the point.

The smectite group clay is represented by the following general formula (2): X _0.2 to _0.6 Y ₂ to ₃ Z ₄ O ₁₀ (OH) ₂ .nH ₂ O (2) (where X is K, Na, 1 / 2Ca , And 1 / 2Mg
At least one member selected from the group consisting of
e, Mn, Ni, Zn, Li, Al, and at least one member selected from the group consisting of Cr, and Z is at least one member selected from the group consisting of Si and Al. Note that H ₂ O represents a water molecule bonded to an interlayer ion, and n varies remarkably depending on the interlayer ion and the relative humidity. Specific examples of the smectite group clay include, for example, montmorillonite,
Examples include beidellite, nontronite, saponite, iron saponite, hectorite, sauconite, stevensite, bentonite, and the like, and substituted substances, derivatives, and mixtures thereof. The distance between the bottom surfaces of the smectite group clay in the initial aggregation state is about 10 to 1
7 °, and the average particle size of the smectite group clay in the agglomerated state is approximately 1000-1,000,000 °.

The swellable mica is represented by the following general formula (3): X _0.5 to _1.0 Y ₂ to ₃ (Z ₄ O ₁₀ ) (F, OH) ₂ (3) (where X is Li, Na, K , Rb, Ca, Ba, and Sr, at least one selected from the group consisting of
g, one or more selected from the group consisting of Fe, Ni, Mn, Al, and Li, and Z is Si, Ge, Al, F
at least one selected from the group consisting of e and B. )
And natural or synthetic. These are substances having the property of swelling in water, a polar solvent compatible with water at an arbitrary ratio, and a mixed solvent of water and the polar solvent. For example, lithium-type teniolite, sodium-type teniolite, lithium-type Examples thereof include silicon mica, sodium tetrasilicic mica, and the like, and substituted substances, derivatives, and mixtures thereof. The distance between the bottom surfaces of the swellable mica in the initial aggregation state is approximately 10 to 17
Å, and the average particle size of the swellable mica in the aggregated state is about 10
It is 00 to 1,000,000 °.

Some of the above-mentioned swellable mica have a structure similar to that of vermiculite, and such a vermiculite equivalent can be used. The said vermiculite such equivalent has three octahedral type and dioctahedral the following general formula (4) (Mg, Fe, Al) 2 ~ 3 (Si 4-x Al x) O 10 (OH) 2 · (M ⁺ , M ²⁺ _1/2 ) _x · nH ₂ O (4) (where M is an exchangeable cation of an alkali or alkaline earth metal such as Na and Mg, x = 0.6 to 0.9) , N =
3.5 to 5). The distance between the bottom surfaces of the vermiculite in the initial aggregation state is about 10 to 17 °, and the average particle size of the vermiculite in the aggregation state is about 1000 to 5,000,000 °.

The swellable silicate may be used alone.
It may be used in combination of more than one kind. Of these,
Montmorillonite, bentonite, hectorite and swellable mica having sodium ions between layers are preferred from the viewpoint of dispersibility in the polyacetal resin composition of the present invention, availability, and effects of improving the physical properties of the resin composition.

The crystal structure of the swellable silicate is desirably high in purity, which is regularly stacked in the c-axis direction. However, a so-called mixed layer mineral in which the crystal cycle is disordered and a plurality of types of crystal structures are mixed is also used. Can be done.

As the silane compound to be introduced into the swellable silicate, any commonly used silane compound can be used, and a compound represented by the following general formula (1) Y _n SiX _4-n (1) It is. N in the general formula (1) is an integer of 0 to 3, and Y is a group having 1 carbon atom which may have a substituent.
~ 25 hydrocarbon groups. When the hydrocarbon group having 1 to 25 carbon atoms has a substituent, examples of the substituent include a group bonded by an ester bond, a group bonded by an ether bond, an epoxy group, an amino group, and a carboxyl group. , A group having a carbonyl group at the terminal, an amide group, a mercapto group, a group bonded by a sulfonyl bond, a group bonded by a sulfinyl bond, a nitro group, a nitroso group, a nitrile group, a halogen atom and a hydroxyl group. . One of these may be substituted, or two or more may be substituted. X is a hydrolyzable group and / or
A hydroxyl group, and examples of the hydrolyzable group include at least one selected from the group consisting of an alkoxy group, an alkenyloxy group, a ketoxime group, an acyloxy group, an amino group, an aminoxy group, an amide group, and a halogen atom. . In the general formula (1), when n or 4-n is 2 or more, n Y or 4-n X may be the same or different.

As used herein, the term "hydrocarbon group" refers to a linear or branched (ie, having a side chain) saturated or unsaturated monovalent or polyvalent aliphatic hydrocarbon group, and an aromatic hydrocarbon group. An alicyclic hydrocarbon group means an alkyl group, an alkenyl group, an alkynyl group, a phenyl group, a naphthyl group, a cycloalkyl group and the like. In the present specification, the term “alkyl group” is intended to include a polyvalent hydrocarbon group such as an “alkylene group” unless otherwise specified. Similarly, the alkenyl group, alkynyl group, phenyl group, naphthyl group, and cycloalkyl group include alkenylene group, alkynylene group, phenylene group, naphthylene group, cycloalkylene group, and the like, respectively.

In the above general formula (1), Y represents 1 carbon atom.
Examples of the hydrocarbon group having from 25 to 25 include those having a linear long-chain alkyl group such as decyltrimethoxysilane, those having a lower alkyl group such as methyltrimethoxysilane, and 2-hexenyltrimethoxy. Those having an unsaturated hydrocarbon group such as silane, those having an alkyl group having a side chain such as 2-ethylhexyltrimethoxysilane, those having a phenyl group such as phenyltriethoxysilane, and 3-β-naphthyl Examples include those having a naphthyl group such as propyltrimethoxysilane, and those having an aralkyl group such as p-vinylbenzyltrimethoxysilane. Examples of the case where Y is a group having a vinyl group among hydrocarbon groups having 1 to 25 carbon atoms include vinyltrimethoxysilane, vinyltrichlorosilane, and vinyltriacetoxysilane. Y
Is a group having a group substituted with a group bonded by an ester group, and examples thereof include γ-methacryloxypropyltrimethoxysilane. Examples of the case where Y is a group having a group substituted with a group bonded by an ether group include γ-polyoxyethylenepropyltrimethoxysilane and 2-ethoxyethyltrimethoxysilane. Examples of a case where Y is a group substituted with an epoxy group include γ-glycidoxypropyltrimethoxysilane. Examples of the case where Y is a group substituted with an amino group include γ-aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, and γ-anilinopropyltrimethoxysilane. No. Examples of the case where Y is a group substituted with a group having a carbonyl group at the terminal include γ-ureidopropyltriethoxysilane. Examples of the case where Y is a group substituted with a mercapto group include γ-mercaptopropyltrimethoxysilane. Examples of a case where Y is a group substituted with a halogen atom include γ-chloropropyltriethoxysilane. Examples of the case where Y is a group having a group substituted with a group bonded by a sulfonyl group include γ-phenylsulfonylpropyltrimethoxysilane. Examples of the case where Y is a group having a group substituted with a group bonded by a sulfinyl group include γ-phenylsulfinylpropyltrimethoxysilane. Examples of a case where Y is a group substituted with a nitro group include γ-nitropropyltriethoxysilane. Examples of the case where Y is a group substituted by a nitroso group include γ-
Nitrosopropyltriethoxysilane may be mentioned. Y
Is a group substituted with a nitrile group, examples thereof include γ-cyanoethyltriethoxysilane and γ-cyanopropyltriethoxysilane. Examples of the case where Y is a group substituted with a carboxyl group include γ- (4-carboxyphenyl) propyltrimethoxysilane. In addition to the above, silane compounds in which Y is a group having a hydroxyl group can also be used. Such an example includes N, N-di (2-hydroxyethyl) amino-3-propyltriethoxysilane. Hydroxyl groups can also be in the form of silanol groups (SiOH).

Substitutes or derivatives of the above silane compounds can also be used. These silane compounds can be used alone or in combination of two or more.

The distance between the bottom surfaces of the silane clay composite used in the present invention can be larger than the initial distance between the bottom surfaces of the swellable silicate due to the presence of the introduced silane compound. For example, a swellable silicate dispersed in a dispersion medium and having an increased bottom surface interval, when the silane-based compound is not introduced, when the dispersion medium is removed, the layers return to a state in which the layers are aggregated again. For example, by introducing the silane compound after expanding the bottom surface interval, even after removing the dispersion medium, the obtained silane clay composite can exist in a state where the bottom surface interval is expanded without the layers being aggregated. . The distance between the bottom surfaces of the silane clay complex is at least 1.3 times, preferably at least 1.5 times, more preferably at least 1.7 times, particularly preferably at least 2 times, the initial distance of the swellable silicate. It is expanding. As described above, the affinity between the silane clay composite and the resin can be increased by introducing the silane-based compound and by increasing the distance between the bottom surfaces.

Here, the introduction of the silane compound into the swellable silicate can be confirmed by various methods. As a method for confirmation, for example, the following method can be mentioned.

First, by simply washing the silane clay complex using an organic solvent such as tetrahydrofuran or chloroform, the adsorbed silane compound is simply washed and removed. The washed silane clay composite is powdered in a mortar or the like and then dried sufficiently. Subsequently, the silane clay composite is sufficiently mixed with a window material such as powdered potassium bromide (KBr) at a predetermined ratio to form a tablet under pressure, and the Fourier transform (FT) -IR is used to perform a transmission method or the like. , The absorption band derived from the silane compound is measured. When more accurate measurement is desired, or when the amount of the introduced silane compound is small, it is possible to measure a sufficiently dried powdery silane clay complex by a diffuse reflection method (DRIFT) as it is. desirable.

The fact that the distance between the bottom surfaces of the silane clay complex is larger than that of the swellable silicate can be confirmed by various methods. For example, the following method can be used.

That is, in the same manner as described above, the adsorbed silane compound is removed from the silane clay composite by washing with an organic solvent, dried, and then subjected to small angle X-ray diffraction (SAX).
S) or the like. In this method, the X-ray diffraction peak angle value derived from the (001) plane of the powdery silane clay composite is measured by SAXS, and the angle is applied to Bragg's formula to calculate the bottom surface interval. Similarly, the base spacing of the initial swellable silicate is measured, and by comparing the two, the expansion of the base spacing can be confirmed.

As described above, after washing with an organic solvent,
The absorption band derived from the added silane compound is FT-IR
By measuring with SAXS or the like that the bottom surface interval is larger than that of the raw material swellable silicate, it can be seen that a silane clay complex has been formed.

In the polyacetal resin composition of the present invention, the compounding amount of the silane clay composite per 100 parts by weight of the polyacetal resin is typically 0.1 to 50 parts by weight,
Preferably 0.2 to 45 parts by weight, more preferably 0.3 to 45 parts by weight.
The amount is adjusted to be 40 parts by weight, more preferably 0.4 to 35 parts by weight, particularly preferably 0.5 to 30 parts by weight. If the amount of the silane clay composite is less than 0.1 part by weight, the effect of improving mechanical properties and warpage may be insufficient, and if it exceeds 50 parts by weight, the surface appearance tends to be impaired.

The ash content of the polyacetal resin composition derived from the silane clay composite is typically 0.1 to 3
0% by weight, preferably 0.2 to 28% by weight, more preferably 0.3 to 25% by weight, still more preferably 0.4 to 23% by weight, particularly preferably 0.5 to 20% by weight. Prepared. If the ash content is less than 0.1% by weight, the effect of improving mechanical properties and warpage may be insufficient, and
If the content exceeds% by weight, the surface appearance tends to be impaired.

The structure of the silane clay composite dispersed in the polyacetal resin composition of the present invention has an agglomerate structure of a μm size in which a number of layers are laminated, such as a swellable silicate before compounding. Completely different. That is, by using a silane clay composite in which a silane-based compound having an affinity for the matrix resin is introduced and the bottom surface interval is increased compared to the initial swellable silicate, the layers are cleaved and become independent from each other. And subdivide it. As a result, the silane clay composite is dispersed in the polyacetal resin composition in a very fine and independent thin plate shape, and the number thereof is significantly increased as compared with the number of the swellable silicate as the raw material. The dispersion state of such a thin silane clay composite can be represented by the aspect ratio (ratio of layer length / layer thickness), the number of dispersed particles, the maximum layer thickness, and the average layer thickness described below.

First, when the average aspect ratio is defined as the number average value of the ratio of the layer length / layer thickness of the silane clay composite dispersed in the resin, the silane clay composite in the polyacetal resin composition of the present invention is defined. Average body aspect ratio is 10-30
0, preferably 15 to 300. More preferably, it is 20 to 300. If the average aspect ratio of the silane clay composite is less than 10, the effect of improving the mechanical properties, sink marks and warpage of the polyacetal resin composition of the present invention may not be sufficiently obtained. Further, even if it is larger than 300, the effect does not change any more, so that it is not necessary to make the average aspect ratio larger than 300.

When the [N] value is defined as the number of dispersed particles per unit weight ratio of the swellable silicate in an area of 100 μm ² of the polyacetal resin composition, the silane in the polyacetal resin composition of the present invention is defined as: The [N] value of the clay composite is 30 or more, preferably 45 or more, and more preferably 60 or more. There is no particular upper limit, but when the [N] value exceeds about 1000, the effect does not change any more. The [N] value can be obtained, for example, as follows. That is, the polyacetal resin composition is
The swelling silicate used was cut out into an ultrathin section having a thickness of 0 μm to 100 μm, and the number of particles of the silane clay complex existing in an arbitrary area having an area of 100 μm ² was determined on an image obtained by photographing the section with a TEM or the like. Divided by the weight ratio of Alternatively, on a TEM image, an arbitrary region (area is measured) in which 100 or more particles are present is selected, and the number of particles present in the region is divided by the weight ratio of the swellable silicate used. The value converted to the area of 100 μm ² may be used as the [N] value. Therefore, the [N] value can be quantified by using a TEM photograph or the like of the polyacetal resin composition.

When the average layer thickness is defined as the number average value of the layer thickness of the silane clay composite dispersed in a thin plate shape,
The upper limit of the average layer thickness of the silane clay composite in the polyacetal resin composition of the present invention is 500 ° or less, preferably 450 ° or less, more preferably 400 ° or less. If the average layer thickness is larger than 500 °, the effect of improving the mechanical properties, sink marks and warpage of the polyacetal resin composition of the present invention may not be sufficiently obtained. The lower limit of the average layer thickness is not particularly limited, but is preferably larger than 50 °,
It is more preferably at least 60 °, still more preferably at least 70 °.
Å or more.

When the maximum layer thickness is defined as the maximum value of the layer thickness of the silane clay composite dispersed in a thin plate shape in the polyacetal resin composition of the present invention, the upper limit of the maximum layer thickness of the silane clay composite is defined. The value is less than 2000 °, preferably less than 1800 °, more preferably 1500 °.
It is as follows. If the maximum layer thickness is more than 2000 °, the balance of the mechanical properties, sink marks, warpage, and surface appearance of the polyacetal resin composition of the present invention may be impaired. The lower limit of the maximum layer thickness of the silane clay composite is not particularly limited, but is preferably larger than 100 °, more preferably 1 °.
It is at least 50 °, more preferably at least 200 °.

The layer thickness and the layer length are determined by heating and melting the polyacetal resin composition of the present invention and then hot pressing or stretching the film, and a thin molded product obtained by injection molding the molten resin. Can be determined from an image captured using a microscope or the like.

That is, the thickness of the film prepared by the above method or the thickness of about 0.5 to 0.5 on the XY plane is now assumed.
It is assumed that a thin flat injection-molded test piece of about 2 mm is placed. Approximately 50 μm to 100 μm of the above film or test piece in a plane parallel to the XZ plane or the YZ plane
The thickness can be determined by cutting out an ultrathin section and observing the section with a transmission electron microscope or the like at a high magnification of about 4 to 100,000 or more. The measurement is performed by placing an arbitrary area containing 100 or more silane clay composites on an elephant of the transmission electron microscope obtained by the above method, forming an image with an image processing device or the like, and performing computer processing. And the like. Alternatively, it can also be obtained by measuring using a ruler or the like.

The method for producing the polyacetal resin composition of the present invention is not particularly limited. For example, (A) a step of preparing a silane clay composite; and (B) a step of preparing a polymerizable monomer of the polyacetal resin and the silane clay composite. Mixing,
(C) a step of polymerizing a polymerizable monomer is preferred.

First, the step (A) will be described in detail. The silane clay composite is obtained, for example, by adding a silane-based compound after expanding the swellable silicate in a dispersion medium to increase the distance between the bottom surfaces.

The above-mentioned dispersion medium means water, a polar solvent compatible with water, and a mixed solvent of water and the polar solvent. Examples of the polar solvent include alcohols such as methanol, ethanol and isopropanol; glycols such as ethylene glycol, propylene glycol and 1,4-butanediol; ketones such as acetone and methyl ethyl ketone; ethers such as diethyl ether and tetrahydrofuran. And amide compounds such as N, N-dimethylformamide and N, N-dimethylacetamide, and other solvents such as pyridine, dimethylsulfoxide and N-methylpyrrolidone. Also, carbonic acid diesters such as dimethyl carbonate and diethyl carbonate can be used. These polar solvents may be used alone or in combination of two or more.

The spacing between the bottom surfaces of the swellable silicate can be increased in the dispersion medium by sufficiently stirring and dispersing the swellable silicate in the dispersion medium. The spacing between the bottom surfaces after the enlargement is preferably at least 3 times, more preferably at least 4 times, particularly preferably at least 5 times, as compared to the initial spacing of the swellable silicate. There is no particular upper limit. However, when the distance between the bottom surfaces is increased by about 10 times or more, the measurement of the distance between the bottom surfaces becomes difficult. In this case, the swellable silicate substantially exists in a unit layer.

Here, in the present specification, the initial distance between the bottom surfaces of the swellable silicate refers to a particulate swellable silicate in which unit layers are stacked and aggregated before being added to the dispersion medium. It is intended to be the bottom spacing.

The distance between the bottom surfaces can be determined by small angle X-ray diffraction (SAXS) or the like. That is, the X-ray diffraction peak angle value of the dispersion containing the dispersion medium and the swellable silicate is determined by SA
XS is measured, and the peak angle value is applied to Bragg's formula to calculate the bottom surface interval.

In order to efficiently increase the distance between the bottom surfaces of the swellable silicate, stirring may be performed at a speed of several thousand rpm or more, or a method of applying a physical external force as described below. Physical external forces can be applied by using commonly performed wet milling of fillers. As a general wet-milling method of a filler, for example, a method using hard particles can be mentioned. In this method, the hard particles, the swellable silicate, and an optional solvent are mixed and stirred, and the swellable silicate is separated by physical collision between the hard particles and the swellable silicate. Hard particles generally used are filler grinding beads, for example, glass beads or zirconia beads. These grinding beads are selected in consideration of the hardness of the swellable silicate or the material of the stirrer, and are not limited to the above-mentioned glass or zirconia. The particle size is also not specifically limited by a numerical value because it is determined in consideration of the size of the swellable silicate and the like, but a particle having a diameter of 0.1 to 6.0 mm is preferable. . Although the solvent used here is not particularly limited, for example, the above-described dispersion medium is preferable.

As described above, the interval between the bottom surfaces of the swellable silicate is enlarged, and the layers in the aggregated state are cleaved to be separated. After the layers are independently present, the silane compound is added and stirred. . In this way, a silane clay composite is obtained by introducing the silane compound to the surface of the cleaved swellable silicate layer.

In the case of using a dispersion medium, the silane-based compound is introduced by adding the silane-based compound to a dispersion containing the swellable silicate having an enlarged bottom surface spacing and the dispersion medium, followed by stirring. Can be done. The method of stirring is not particularly limited, and for example, is performed using a conventionally known wet stirrer.
Examples of the wet stirrer include a high-speed stirrer in which a stirring blade rotates at a high speed and stirs, a wet mill for wet-milling a sample in a gap between a rotor and a stator at a high shear rate, and a mechanical method using a hard medium. Examples include wet crushers and wet crushers that collide a sample at a high speed with a jet nozzle or the like. When it is desired to introduce the silane compound more efficiently, the rotation speed of the stirring should be 1000 rpm or more,
Preferably 1500 rpm or more, more preferably 200 rpm
The shear rate is set to 0 rpm or more, or 500 (1 / s) or more, preferably 1000 (1 / s) or more, and more preferably 1500 (1 / s) or more. The upper limit of the number of revolutions is about 25,000 rpm, and the upper limit of the shear rate is about 500,000 (1 / s). It is not necessary to stir at a value larger than the upper limit since stirring does not tend to change the effect even if the stirring is performed at a value larger than the upper limit or shearing is applied.

In the case of a method using a physical external force, a silane compound is added thereto while applying a physical external force to the swellable silicate (for example, while wet milling).
A silane compound may be introduced.

Alternatively, by adding a swellable silicate having an increased bottom distance by a physical external force to a dispersion medium and adding a silane compound to the dispersion medium in the same manner as in the above-described method using a dispersion medium. Alternatively, a silane compound can be introduced into the swellable silicate.

The introduction of the silane compound into the swellable silicic acid is carried out by reacting a hydroxyl group present on the surface of the swellable silicate having an increased bottom distance with a hydrolyzable group and / or a hydroxyl group of the silane compound. By doing so, a silane compound can be introduced into the swellable silicate.

When the silane compound introduced into the swellable silicate further has a reactive group such as a hydroxyl group, a carboxyl group, an amino group, an epoxy group, or a vinyl group, such a silane compound may be used. It is also possible to further add a compound capable of reacting with a reactive group and react the compound with the reactive group. Thus, the chain length of the functional group chain of the silane compound introduced into the swellable silicate and the polarity can be changed. In this case, as the compound to be added, the above-mentioned silane-based compound itself can be used, but the compound is not limited thereto, and any compound can be used according to the purpose. For example, an epoxy group-containing compound, an amino group Examples of the compound include a compound containing a carboxyl group, a compound containing an acid anhydride group, and a compound containing a hydroxyl group.

The reaction proceeds sufficiently at room temperature, but may be heated if necessary. The maximum temperature during heating can be arbitrarily set as long as it is lower than the decomposition temperature of the silane compound used and lower than the boiling point of the dispersion medium. The amount of the silane compound used is determined by the affinity between the obtained silane clay composite and the polyacetal resin, or a mixture containing a polymerizable monomer of the silane clay composite and the polyacetal resin (hereinafter, clay-based resin).
(Referred to as monomer dispersion) can be adjusted so as to sufficiently enhance the dispersibility. If necessary, a plurality of silane compounds having different functional groups may be used in combination. Therefore,
The amount of the silane-based compound added is not generally limited by numerical values, but based on 100 parts by weight of the swellable silicate,
0.1 to 200 parts by weight, preferably 0.2 to 1 part by weight.
It is 80 parts by weight, more preferably 0.3 to 160 parts by weight, still more preferably 0.4 to 140 parts by weight, particularly preferably 0.5 to 120 parts by weight.
When the amount of the silane compound is less than 0.1 part by weight, the effect of finely dispersing the obtained silane clay composite tends to be insufficient. If the amount is more than 200 parts by weight, the effect does not change. Therefore, it is not necessary to add more than 200 parts by weight.

Next, step (B), that is, a step of mixing the silane clay composite and the polymerizable monomer of the polyacetal resin is performed. Here, the polymerizable monomer of the polyacetal resin, as described above, in addition to formaldehyde and trioxane, cyclic ether or cyclic formal as a comonomer, for example, ethylene oxide, propylene oxide, butylene oxide, 1,3-dioxolan,
Examples thereof include 1,3-dioxane, 1,4-butanediol formal, diethylene glycol formal, and trioxeopan, and one or more of these may be used. The amount of comonomer used is 0.1 relative to trioxane.
~ 12% is preferred. The method for preparing the clay-monomer dispersion by mixing the polymerizable monomer of the polyacetal resin and the silane clay composite is not particularly limited, and may be performed using the above-described conventionally known wet stirrer. In addition to the method of directly mixing the composite and the polymerizable monomer, as shown below, first, a mixture containing the dispersion medium and the silane clay composite is prepared, and the method of adding the polymerizable monomer thereto and mixing the mixture is exemplified. Can be

The above mixture is prepared by mixing the silane clay composite and the above-mentioned dispersion medium. The method for preparing the mixture is not particularly limited. For example, a method using a system containing a dispersion medium and a silane clay complex as obtained as a mixture, which is obtained when a silane clay composite is prepared (referred to as a direct method),
Alternatively, the desired dispersion newly added by adding and mixing another desired dispersion medium to the system containing the dispersion medium and the silane clay complex, which is obtained when the silane clay composite is prepared, and then replacing the dispersion medium. A method using a system comprising a solvent and a silane clay composite as a mixture (referred to as a substitution method), or a method of thoroughly mixing a silane clay composite obtained by drying and removing a dispersion medium with a desired dispersion medium, and the like. Can be

For efficient mixing, the rotation speed of the stirring should be 500 rpm or more, or 300 (1 / s).
Apply the above shear rate. The maximum number of revolutions is 25000
rpm, and the upper limit of the shear rate is 500000 (1 /
s). There is a tendency that the effect does not change even if the stirring is performed at a value larger than the upper limit, so that it is not necessary to perform the stirring at a value larger than the upper limit.

In the silane clay composite contained in the clay-monomer dispersion obtained in the step (B), the initial lamination / agglomeration structure, which the swellable silicate had, had almost completely disappeared, and the sheet was thin. The layers are subdivided into shapes, or the intervals between the layers are enlarged, so that a so-called swollen state is obtained. The bottom surface interval can be used as an index indicating the swelling state. The distance between the bottom surfaces of the silane clay composite in the clay-monomer dispersion is preferably at least three times the initial distance between the bottom surfaces of the swellable silicate in order for the silane clay composite to be finely divided and formed into a thin plate. It is more preferably at least five times, more preferably at least five times.

Then, step (C), that is, a step of polymerizing a polymerizable monomer can be performed. The polymerization method is not particularly limited, and a polymerization method of a polyacetal resin generally performed generally, for example, (a) a method using formaldehyde or trioxane as a main monomer, (b) a method using trioxane as a main monomer, and a cyclic ether or cyclic formal as a comonomer And (c) a method using formaldehyde as a main monomer and a cyclic ether or cyclic formal as a comonomer.

That is, for example, according to the method (A), the clay-monomer dispersion containing the silane clay complex and the polymerizable monomer (formaldehyde or trioxane) obtained in the step (B) is treated with water. ,methanol,
Compounds having active hydrogen such as formic acid are removed. Then
Anion polymerization is performed using a catalyst such as an ammonium salt while removing the heat of polymerization. When the molecular weight has risen sufficiently,
The polymerization is terminated by stabilizing the terminal hydroxyl groups of the polymer by terminal esterification with acetic anhydride or the like. According to the above method, a polyacetal resin composition using a homopolymer of polyacetal as a matrix resin can be obtained.

According to the above method (b), a clay-monomer dispersion containing a silane clay composite and a polymerizable monomer (trioxane as a main monomer and a cyclic ether or cyclic formal as a comonomer) is mixed. And water or methanol having active hydrogen acting as a chain transfer agent is removed. Then, a cationic polymerization catalyst such as boron trifluoride or a coordination compound thereof or various protonic acid catalysts is added, and copolymerization can be performed by bulk polymerization or the like. After polymerization, a basic compound such as triethylamine, or
The polymerization is terminated by stabilizing the polymer with a chain transfer agent such as a low molecular weight linear acetal such as a methylalal having an alkoxy group at both ends. According to the above method, a polyacetal resin composition using the copolymerized polyacetal resin as a matrix resin can be obtained.

The reasons why the polyacetal resin composition of the present invention has a small warp and sink and does not impair the surface appearance are as follows.
The silane clay composite is dispersed in the polyacetal resin as a large number of small thin plate-like particles, and the average layer thickness, the maximum layer thickness, the number of dispersed particles, and the average aspect ratio of the silane clay composite, which are indicators of the dispersion state, Is within the range described above.

The dispersion state of the silane clay composite can be determined by the step (A) in the method for producing a polyacetal resin composition described above.
And one or more steps selected from step (B).

For example, in the step (A), the dispersion state of the silane clay composite can be controlled by the organic functional group of the silane compound to be introduced, the amount of the silane compound used, the type of the dispersion medium to be used, and the like. Assuming that the stirring force and shearing force when dispersing the swellable silicate are constant, the type of the dispersion medium, and when using a plurality of types of dispersion medium, the swelling is performed according to the mixing ratio and the order of mixing. The state of swelling and cleavage of the silicate changes. For example, when montmorillonite is used as the swellable silicate, if the dispersion medium is only water, montmorillonite swells and cleaves to a state close to the unit layer, and in that state, an amino group, a mercapto group, a nitrile group, etc. By reacting a silane compound having a highly polar group, a dispersion in which a silane clay composite having a unit layer thickness of approximately approximately is dispersed is prepared. On the other hand, ethanol, tetrahydrofuran (THF), methyl ethyl ketone (MEK), pyridine, N, N-dimethylformamide (DMF),
When a mixed solvent of a polar solvent such as N, N-dimethylacetamide (DMAc) and N-methylpyrrolidone (NMP) and water is used as a dispersion medium, or when montmorillonite is dispersed in the polar solvent and then water is added. Is cleaved and subdivided into a state in which about several to several hundreds of unit layers are stacked. By reacting the silane compound in this state, a dispersion in which the silane clay composite having a thickness of about several to about one hundred and several tens of sheets is dispersed is prepared. The dispersion state of the silane clay composite can be controlled by performing steps (B) and (C) in the method for producing a polyacetal resin composition so as to maintain those states.

Further, in the step (B), the mixing conditions of the silane clay composite and the polymerizable monomer, for example, the number of stirring, the shearing force at the time of stirring, and the stirring time, are used to adjust the silane clay composite in the clay-monomer dispersion. The swelling state is controlled. The dispersion state of the silane clay composite can be controlled by performing the step (C) in the method for producing a polyacetal resin composition so as to maintain those states.

The polyacetal resin composition of the present invention includes:
If necessary, polybutadiene, butadiene-styrene copolymer, acrylic rubber, ionomer, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, natural rubber, chlorinated butyl rubber, homopolymer of α-olefin, Impact resistance of a copolymer of two or more α-olefins (including any copolymer such as random, block and graft, or a mixture thereof), or a thermoplastic elastomer such as an olefin-based elastomer A property improver can be added. These may be modified with an acid compound such as maleic anhydride or an epoxy compound such as glycidyl methacrylate. Also,
Mechanical properties, as long as properties such as moldability are not impaired, any other resin, for example, polyester resin, polycarbonate resin, polyester carbonate resin, liquid crystal polyester resin, polyolefin resin, styrene resin,
Thermoplastic resins such as rubbery polymer reinforced styrene resin, polyamide resin, polyphenylene sulfide resin, polyphenylene ether resin, polyarylate resin, polysulfone resin, polyimide, polyetherimide resin,
A thermosetting resin such as an unsaturated polyester resin, an epoxy resin, and a phenol novolak resin may be used alone or in combination of two or more.

Further, the polyacetal resin composition of the present invention may contain a pigment, a dye, a heat stabilizer, an antioxidant, an ultraviolet absorber, a light stabilizer, a lubricant, a plasticizer, a flame retardant,
And an additive such as an antistatic agent. The polyacetal resin composition of the present invention may be molded by injection molding, extrusion molding, hot press molding, or can be used for blow molding.

In the polyacetal resin composition of the present invention, the silane clay composite is very fine and thin and plate-like, and is uniformly dispersed, so that the surface appearance is not impaired and the specific gravity is not significantly increased. , Warpage and sink can be improved.

[0070]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention.

The main raw materials used in the examples and comparative examples are shown below. Unless otherwise specified, the raw materials were not purified. Trioxane: Trioxane from Wako Pure Chemical Industries, Ltd. (hereinafter referred to as trioxane) was used.・ Swellable silicate: Kunimine F Co., Ltd.
(Hereinafter, referred to as Kunipia F, bottom spacing = 13 °), and Wenger HVP of Toyshun Yoko Co., Ltd. (hereinafter, referred to as Wenger HVP, bottom spacing = 13 °). -Γ-aminopropyltrimethoxysilane: A-1110 from Nippon Unicar Co., Ltd. (hereinafter referred to as A1110) was used. Γ- (polyoxyethylene) propyltrimethoxysilane: A-1230 of Nippon Unicar Co., Ltd. (hereinafter A1
230). -Polyethylene glycol diglycidyl ether: Polyethylene glycol diglycidyl ether (hereinafter referred to as PEGDG) of Sakamoto Yakuhin Kogyo Co., Ltd. was used. Also,
Evaluation methods in Examples and Comparative Examples are summarized below. (FT-IR) 1.0 g of the silane clay complex was added to 50 ml of tetrahydrofuran (THF), and the mixture was stirred for 24 hours to wash and remove the adsorbed silane compound, and then centrifuged to separate the supernatant. This washing operation was repeated three times. After washing, a well dried silane clay complex about 1
mg and about 200 mg of KBr powder were sufficiently mixed in a mortar, and a KBr disk for measurement was prepared using a tabletop press. Next, an infrared spectrometer (Shimadzu Corporation, 810
0M) by the transmission method. The detector used was an MCT detector cooled with liquid nitrogen, the resolution was 4 cm ⁻¹ , and the number of scans was 100. (Measurement of dispersion state) Regarding the silane clay composite, TE
The following procedure was performed using M.

Ultrathin sections having a thickness of 50 to 100 μm were used. Transmission electron microscope (JEOL JEM-1200E
Using X), the dispersion state of the silane clay composite was observed and photographed at an acceleration voltage of 80 kV and a magnification of 40,000 to 1,000,000 times. TEM
In the photograph, a region where 100 or more dispersed particles are present is selected, and the number of particles ([N] value), layer thickness and layer length are manually measured using a ruler with a scale, or interquest as required. The measurement was performed by processing using an image analysis device PIASIII of the company. The average aspect ratio was a number average value of the ratio between the layer length and the layer thickness of each silane clay composite.
[N] value was measured as follows. First, TE
On the M image, the number of particles of the silane clay composite present in the selected area is determined. Separately, the ash content of the resin composition derived from the silane clay composite is measured. The value obtained by dividing the number of particles by the ash content and converting the result to an area of 100 μm ² was defined as the [N] value.

The average layer thickness was the number average of the layer thicknesses of the individual silane clay composites, and the maximum layer thickness was the maximum value among the layer thicknesses of the individual silane clay composites.

When the dispersed particles are large and observation with a TEM is inappropriate, the [N] value can be determined using an optical microscope (optical microscope BH-2 manufactured by Olympus Optical Co., Ltd.) in the same manner as described above. I asked. However, if necessary, the sample was melted at 190 to 210 ° C. using a hot stage THM600 manufactured by LINKAM, and the state of the dispersed particles was measured in the molten state.

The aspect ratio of the dispersed particles that do not disperse in a plate shape was the value of major axis / minor axis. Here, the long diameter is intended to be the long side of the rectangle assuming a rectangle having the smallest area among rectangles circumscribing the target particle in a microscope image or the like. Further, the minor axis is intended to mean the short side of the minimum rectangle. (Measurement of bottom spacing by small angle X-ray diffraction (SAXS))
Using an X-ray generator (RU-200B, manufactured by Rigaku Corporation), target CuKα ray, Ni filter, voltage 4
0 kV, current 200 mA, scanning angle 2θ = 0.2 to 16.0
°, the step angle = 0.02 ° under the measurement conditions, the bottom spacing was measured.

The distance between the bottom surfaces is represented by a small angle X-ray diffraction peak angle value of B
It was calculated by substituting into the formula of ragg. However, when it is difficult to confirm the small-angle X-ray peak angle value, it is confirmed that the layer has been sufficiently cleaved and the crystallinity has substantially disappeared, or the peak angle value is approximately 0.8 ° or less. Was considered difficult, and the evaluation result of the bottom surface spacing was set to> 100 °. (Warp) Dry the polyacetal resin composition (120 ° C,
5 hours), using an injection molding machine (IS-75E, manufactured by Toshiba Machine Co., Ltd.) with a mold clamping pressure of 75 t, using a mold temperature of 50 ° C., a resin temperature of 200 ° C., a gauge pressure of about 10 MPa, and an injection speed of about 5 MPa.
Injection molding under 0% condition, dimension about 120 × 120 × 1
mm plate-shaped test pieces were prepared. The flat test piece was placed on a flat surface, and the degree of warpage was checked. (Surface appearance) Dry the polyacetal resin composition (120
C. for 5 hours). Using an injection molding machine (IS-75E, manufactured by Toshiba Machine Co., Ltd.) with a mold clamping pressure of 75 t, a resin temperature of 200
C., a gauge pressure of about 10 MPa, and an injection speed of about 50%, a JIS No. 1 dumbbell-shaped test piece having a thickness of about 3 mm was injection-molded, and the center line average roughness was evaluated. The center line surface roughness is a surface roughness meter manufactured by Tokyo Seimitsu Co., Ltd .;
It measured using A. (Bending Characteristics) A test piece having a size of about 10 × 100 × 6 mm was injection-molded under the same conditions as the above-mentioned dumbbell-shaped test piece. The flexural strength and flexural modulus of the obtained test piece were determined by ASTM D
Measured according to -790. (Ash content) The ash content of the polyacetal resin composition derived from the silane clay composite was measured according to JIS K7052. (Example 1) Step (A) 160 g of Kunipia F was added to 3500 g of ion-exchanged water, and 5000 rpm was used using a wet mill manufactured by Nippon Seiki Co., Ltd.
m, and mixed by stirring for 5 minutes. Then 30 g of A11
After adding 10 and stirring further under the conditions shown in Table 1, a silane clay composite was prepared. (Confirmation of the silane clay complex is as follows:
The measurement was performed by measuring the bottom surface interval by AXS and measuring the absorption band of the functional group derived from the silane compound by FT-IR after washing with THF. Table 1 shows the results
Shown in ).

[0077]

[Table 1] Next, 30 g of PEGDG was added, and stirring was continued for another 30 minutes, followed by dry powdering. Step (B) The silane clay composite obtained in Step (A) and 2400 g of trioxane are sufficiently mixed with a high-speed stirrer (5000 rpm × 3).
(0 min, 80 ° C.). The bottom spacing of the silane clay composite in the clay-monomer dispersion was> 100 °. Step (C) While stirring the clay-monomer dispersion obtained in Step (B) at 80 ° C., 1.25 g of methylal and 0.8 g
Of boron trifluoride in the presence of the silane clay complex,
The trioxane was polymerized. Subsequently, a 0.1% aqueous solution of triethylamine at 30 ° C. was added, and the system was cooled to obtain a polyacetal resin composition. Table 2 shows the evaluation results.

[0078]

[Table 2] (Example 2) Step (A) The amount of A1110 was 15 g, and the amount of PEGDG was 15 g.
A silane clay composite was prepared in the same manner as in Example 1, except that The results are shown in Table 1. Step (B) The silane clay composite and trioxane were mixed in the same manner as in Example 1. The bottom spacing of the silane clay composite in the clay-monomer dispersion was 75 °. Step (C) Performed in the same manner as in Example 1 to obtain and evaluate a polyacetal resin composition. The results are shown in Table 2. (Example 3) Step (A) 20 g of A1110 was used, and 20 g was used instead of PEGDG.
A1230 (previously hydrolyzed with PH 3.0) was used to prepare a silane clay composite in the same manner as in Example 1. The results are shown in Table 1. Step (B) The silane clay composite and trioxane were mixed in the same manner as in Example 1. The bottom spacing of the silane clay composite in the clay-monomer dispersion was 69 °. Step (C) Performed in the same manner as in Example 1 to obtain and evaluate a polyacetal resin composition. The results are shown in Table 2. (Example 4) Step (A) A silane clay composite was prepared in the same manner as in Example 1 except that 180 g of Wengel HVP was used instead of Kunipia F. The results are shown in Table 1. Step (B) The silane clay composite and trioxane were mixed in the same manner as in Example 1. The bottom spacing of the silane clay composite in the clay-monomer dispersion was> 100 °. Step (C) Performed in the same manner as in Example 1 to obtain and evaluate a polyacetal resin composition. The results are shown in Table 2. Comparative Example 1 A polyacetal resin was obtained by polymerizing trioxane in the same manner as in Example 1 except that the silane clay composite was not used, and evaluated. The results are shown in Table 3.

[0079]

[Table 3] Comparative Example 2 A polyacetal resin was polymerized and evaluated in the same manner as in Example 1 except that 160 g of Kunipia F was used instead of the silane clay composite. The results are shown in Table 3. (Comparative Example 3) 160 g of Kunipia F, 30 g of A111
Kunipia F was treated by mixing 0 and 30 g of PEGDG directly for 1 hour at room temperature. The distance between the bottom surfaces of the silane-treated Kunipia F was 13 °. A polyacetal resin was polymerized and evaluated in the same manner as in Example 1 except that the above-mentioned silane-treated Kunipia F was used instead of the silane clay composite. The results are shown in Table 3. (Comparative Example 4) 768 g of ion-exchanged water and 256 g of Kunipia F were mixed by applying ultrasonic waves to swell Kunipia F.

Twin screw extruder (Nippon Steel Corporation, TEX4
4), using a temperature of 190 to 200 ° C. and a rotation speed of 350 rpm
Under the conditions of m, 3900 g of the polyacetal resin polymerized in the same manner as in Comparative Example 1 and the above mixture were melt-kneaded. The results are shown in Table 3. (Comparative Example 5) 2400 g of polyacetal resin polymerized in the same manner as in Comparative Example 1 and 270 g of glass fiber T1
95H is a twin screw extruder (LABOT, manufactured by Nippon Steel Corporation)
EX30) at a temperature of 190 to 200 ° C. and a rotation speed of 10
The mixture was melt-kneaded at 0 rpm. The results are shown in Table 3.

[0081]

According to the present invention, the unit layers of the swellable silicate are separated and cleaved in the polyacetal resin, and the aggregated particles of the swellable silicate are subdivided into a very large number of very small thin plate-like layers. By doing so, it is possible to improve warpage and sinkage without impairing the surface appearance and without significantly increasing the specific gravity, and to obtain a polyacetal resin composition having significantly improved bending properties.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09C 3/08 C09C 3/08

Claims (7)

[Claims] 1. A polyacetal resin composition containing a polyacetal resin and a silane clay composite, wherein the silane clay composite is converted into a swellable silicate by the following general formula (1): Y _n SiX _4-n (1) ( Here, n is an integer of 0 to 3, and Y is 1 to 3 carbon atoms.
X is a hydrolyzable group and / or a hydroxyl group, which is an organic functional group composed of 25 hydrocarbon groups and a hydrocarbon group having 1 to 25 carbon atoms and a substituent. n Y and 4-n X may be the same or different. A) a polyacetal resin composition prepared by introducing a silane compound represented by the formula (1), wherein the average layer thickness of the silane clay composite in the resin composition is 500 ° or less. 2. The maximum thickness of the silane clay composite is 2000.
ポ リ The polyacetal resin composition according to claim 1, wherein 3. The [N] value is 30 or more, where the [N] value is defined as the number of particles per unit ratio of the silane clay complex present in an area of 100 μm ² of the resin composition. The polyacetal resin composition according to claim 1, which is used. 4. The polyacetal resin composition according to claim 1, wherein the silane clay composite has an average aspect ratio (ratio of layer length / layer thickness) of 10 to 300. 5. A polyacetal resin composition containing a polyacetal resin and a silane clay composite, wherein the silane clay composite is converted into a swellable silicate by the following general formula (1): Y _n SiX _4-n (1) ( Here, n is an integer of 0 to 3, and Y is 1 to 3 carbon atoms.
X is a hydrolyzable group and / or a hydroxyl group, which is an organic functional group composed of 25 hydrocarbon groups and a hydrocarbon group having 1 to 25 carbon atoms and a substituent. n Y and 4-n X may be the same or different. ) Is prepared by introducing a silane compound represented by the formula (1), and the resin composition has an average aspect ratio (ratio of layer length / layer thickness) of 10 to 300, and [ N] value is 30 or more, wherein the [N] value is defined as the number of particles per unit ratio of the silane clay complex present in an area of 100 μm ^{2 of the} resin composition. object. 6. A method comprising: (A) a step of preparing a silane clay composite; (B) a step of mixing the polymerizable monomer of the polyacetal resin with the silane clay composite; and (C) a step of polymerizing the polymerizable monomer. A method for producing the polyacetal resin composition according to claim 1, 2, 3, 4, or 5. 7. The method according to claim 1, wherein the distance between the bottom surfaces of the silane clay composite after being mixed with the polymerizable monomer of the polyacetal resin in the step (B) is at least three times the distance between the bottom surfaces of the swellable silicate. A method for producing the polyacetal resin composition according to claim 6.