JP2000109691A - Polyimide resin composition and preparation thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide polyimide resin compositions which do not mar surface appearance and inhibit an increase in specific gravity and warpage and excel in mechanical properties. SOLUTION: Polyimide resin compositions comprise a polyimide resin and a silane clay composite, and the silane clay composite is prepared by introducing a silane compound represented by the formula: YnSiX4-n (wherein n is an integer of 0-3; Y is a 1-25C hydrocarbon group or an organic group constituted by a 1-25C hydrocarbon group and a substituent; X is a hydrolyzable group and/or a hydroxyl group; and respective Y of n and respective X of 4-n may be the same or different from one another) into a swelling silicate salt, and the average layer thickness of the silane clay composite in the polyimide resin composition is not more than 500 Å.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyimide resin composition containing a polyimide resin and a silane clay composite, and to a method for producing the resin composition.

[0002]

2. Description of the Related Art Polyimide has thermal properties, mechanical properties,
Due to its excellent electrical insulation properties and chemical resistance, the molded products are widely used for various industrial parts such as office equipment and automobile parts. However, depending on the application, further improvement in dimensional stability such as a coefficient of thermal expansion and improvement in mechanical properties such as toughness are demanded. In order to cope with such a problem, addition of a filler, modification of a molecular structure, and the like have been performed (for example, JP-A-61-250030 and JP-A-1-292935). However, it is difficult to improve the required properties in a well-balanced manner by the conventional techniques.

[0003] The above-mentioned drawbacks in the blending of the fibrous inorganic substance and the particulate inorganic substance are generally considered to be caused by poor dispersion of the inorganic substance and an excessively large size of the dispersed particles.

[0004] As a technique for finely dispersing inorganic substances, International Publication No. 95-06090, US Pat. No. 5,514,734,
WO 93-04118 and WO 9
And the method disclosed in JP-A-3-11190.
According to the publication, a resin composite containing a resin matrix and a layered particle or the like having an average layer thickness of about 50 ° or less and a maximum layer thickness of about 100 ° or less is bonded to an organometallic compound such as a silane-based compound. An invention relating to a material is disclosed, and a nylon 6-based composite material comprising montmorillonite treated with a silane-based compound and nylon 6 as a resin matrix is disclosed. According to the above technology, the tensile modulus of the nylon 6-based composite material comprising montmorillonite and nylon 6 bonded with isocyanatopropyltriethoxysilane and the like to which caprolactam has been copolymerized is improved as compared with nylon 6 alone. Is not enough.

[0005]

As described above, a nylon 6-based composite material has been disclosed. However, by directly applying the nylon 6-based method to the polyimide resin, a polyimide resin in which layered particles are finely dispersed is obtained. It was difficult to make a composite material.

[0006] On the other hand, in Japanese Patent Application Laid-Open No. Hei 9-118792, when layered particles are separated one by one into a polypropylene resin or a vinyl polymer and dispersed molecularly, the layered particles form a laminate structure. , Making it difficult to express isotropic physical properties (Clay Science, 30 (2), 143-147)
(1990)), and it has been pointed out that when layered particles having a high elastic modulus by themselves are separated into a state close to a unit layer, they are distorted, and the elastic modulus originally expected cannot be obtained.

Further, the present inventors have obtained a composite material by incorporating layered particles into a polyimide resin in a very thin plate-like structure close to the unit layer (layer thickness of the unit layer is about 10 °), and evaluating the physical properties. As a result, it was found that the mechanical properties were improved, but the effect was by no means sufficient, as compared with those in which the layered particles were contained in the polyimide resin in the laminated / agglomerated state. .

[0008] Therefore, the layered silicate has an average layer thickness of about 50.
Even when dispersed in a resin matrix in a state close to the unit layer such that the maximum layer thickness is about 100 mm or less,
Or even if it is contained in a state of being laminated and aggregated,
In any case, it is difficult to obtain a polyimide resin composition having an excellent balance among mechanical properties, surface properties, dimensional stability and specific gravity. In order to obtain a polyimide resin composition having a good balance of physical properties, it is essential to disperse layered particles having an appropriate layer thickness.

However, at present, such a technique has not been provided yet, and an object of the present invention is to solve such a conventional problem.

[0010]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, have reached the present invention. That is, the unit layers of the swellable silicate are separated and cleaved,
A sheet-like silane clay composite prepared by subdividing aggregated particles of two swellable silicates into a very large number of very small sheet-like particles is obtained by being contained in a polyimide resin, polyimide A resin composition and a method for producing the same.

According to the present invention, a polyimide resin composition according to claim 1 is a polyimide resin composition containing a polyimide resin and a silane clay composite, wherein the silane clay composite is formed into a swellable silicate by the following general method. equation _{(1) Y n SiX 4-} n (1) ( where, n is an integer of 0 to 3, Y is 1 to 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 the silane compound represented by the formula (1), and the average layer thickness of the silane clay composite in the resin composition is 500 ° or less.

According to a second aspect of the present invention, there is provided the polyimide resin composition according to the first aspect, wherein the maximum thickness of the silane clay composite is 2000 ° or less.

[0013] The polyimide resin composition according to claim 3 is a polyimide resin composition containing a polyimide 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, 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.

[0014] The polyimide resin composition according to claim 4 is the polyimide resin composition according to claim 1 or 2,
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.

[0015] The polyimide resin composition according to claim 5 is the polyimide resin composition according to claim 1 or 2,
The average aspect ratio (layer length / layer thickness ratio) of the silane clay composite in the resin composition is 10 to 300.

The method for producing a polyimide resin composition according to claim 6 is the method for producing a polyimide resin composition according to claim 1, 2, 3, 4, or 5, wherein (A) the silane clay composite and the dispersion are dispersed. Preparing a clay dispersion containing a medium, (B)
The method includes a step of mixing a polymerizable prepolymer of a polyimide resin with the above clay dispersion, and a step of (C) polymerizing the polymerizable prepolymer.

According to a seventh aspect of the present invention, there is provided the method for producing a polyimide resin composition according to the sixth aspect, wherein the distance between the bottom surfaces of the silane clay composite in the clay dispersion obtained in the step (A) is swollen. It is at least three times as large as the distance between the bottom surfaces of the basic silicate.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The polyimide resin used in the present invention is not particularly limited. In addition to a wholly aromatic polyimide obtained by polycondensation of an aromatic acid anhydride and a diamine, a thermosetting polyimide resin may be used. And bismaleimide-based polyimides, polyparabanic acid obtained from diisocyanate and hydrocyanic acid, etc., and among them, wholly aromatic polyimide (hereinafter, referred to as polyimide) is preferable. Polyimide is generally obtained by forming a polyimide intermediate polymer by a ring-closing reaction. The polyimide intermediate polymer is obtained by a polycondensation reaction between a diamine and an acid dianhydride, and is, for example, polyamic acid. As the monomer of the intermediate polymer, all acid anhydrides and diamines which are known polyimide raw materials can be used. Examples of the acid anhydride include pyromellitic dianhydride and biphenyltetracarboxylic dianhydride. Anhydrides, benzophenonetetracarboxylic dianhydride and the like. Examples of the diamine include 4,4′-diaminodiphenyl ether and 3,4 ′.
-Diaminodiphenyl ether, p-phenylenediamine, m-phenylenediamine and the like.

The polyimide intermediate polymer may be homopolymerized to synthesize a homopolymer. Alternatively, a copolymer composed of several types of monomers may be synthesized. It is also possible to copolymerize dicarboxylic acids, diols and derivatives thereof and use them as intermediate polymers of polyamide imide, polyester amide imide and polyester imide.

As the aprotic polar solvent, N, N-
Dimethylformamide, N, N-dimethylacetamide,
N-methylpyrrolidone, 1,3-dimethylimidazolinone and the like can be mentioned.

Heating the polyamic acid solution of the intermediate polymer or adding a dehydrating agent and an amine-based catalyst to promote ring-closing polymerization can precipitate a polyimide powder.

This powder is usually formed into a predetermined shape by a sintering method under a constant temperature and a high pressure.

[0023] a silane clay complex used in the present invention is represented by the following general formula swellable silicate _{(1) Y n SiX 4-} n (1) ( where, n is an integer of 0 to 3, Y 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, and examples thereof include smectite group clay and swellable mica. Can be When a smectite group clay and swellable mica are used as the swellable silicate, the dispersibility of the swellable silicate in the polyimide resin composition of the present invention, the availability and the improvement of the physical properties of the resin composition are improved. 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. H2O represents a water molecule bonded to an interlayer ion, and n is remarkably fluctuated according to 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 product may be used.

[0028] The in 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 polyimide resin composition of the present invention, availability, and the effect 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 one generally used can be used, and the silane compound is 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 has 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).

[0034] Substitutes or derivatives of the above silane compounds may also be used. These silane compounds can be used alone or in combination of two or more.

The silane clay composite is obtained, for example, by adding a silane-based compound after expanding the distance between the bottom surfaces of a swellable silicate in a dispersion medium.

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. These polar solvents may be used alone or in combination of two or more.

The expansion of the distance between the bottom surfaces of the swellable silicate in the dispersion medium can be achieved 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 is substantially present in a unit layer.

Here, in the present specification, the initial distance between the bottom surfaces of the swellable silicate means 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 effectively 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 spacing between the bottom surfaces of the swellable silicate is enlarged, and the layers that have been 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. When it is desired to introduce the silane compound more efficiently, the rotation speed of the stirring is set to 1000 rpm.
Or more, preferably 1500 rpm or more, more preferably 2000 rpm or more, or 500 (1 / s) or more, preferably 1000 (1) using a wet mill or the like.
/ S) or more, more preferably 1500 (1 / s) or more. The upper limit of the number of revolutions is about 25,000 rp
m, and the upper limit of the shear rate is about 500000 (1 /
s). Stir with a value larger than the upper limit,
It is not necessary to stir at a value greater than the upper limit because the effect does not tend to change any further when shearing is applied.

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

Alternatively, by adding a swellable silicate having an enlarged bottom surface spacing 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 such that the dispersibility of the silane clay composite in the clay dispersion, the affinity between the silane clay composite and the resin, and the dispersibility of the silane clay composite in the polyimide resin composition are sufficient. Can be prepared. If necessary, a plurality of silane compounds having different functional groups may be used in combination. Therefore, the amount of the silane compound to be added is not limited to a numerical value, but is 0.1 to 200 parts by weight, preferably 0.2 to 180 parts by weight, based on 100 parts by weight of the swellable silicate. Parts by weight, more preferably from 0.3 to 160 parts by weight, even more preferably from 0.4 to 140 parts by weight, particularly preferably from 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. Also, 20
If the amount is more than 0 parts by weight, the effect does not change, so it is not necessary to add more than 200 parts by weight.

The distance between the bottom surfaces of the silane clay composite obtained as described above can be enlarged as compared with 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.

The fact that the silane compound has been introduced into the swellable silicate can be confirmed by various methods. As a method for confirmation, for example, the following method can be mentioned. First, the adsorbed silane compound is simply washed and removed by washing the silane clay complex with an organic solvent such as tetrahydrofuran or chloroform. 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.

It can be confirmed by various methods that the distance between the bottom surfaces of the silane clay composite is larger than that of the swellable silicate. As a method for confirmation, for example, the following method can be mentioned.

That is, in the same manner as described above, the adsorbed silane-based compound is removed from the silane-clay composite by washing with an organic solvent, and after drying, the small-angle X-ray diffraction method (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.

After washing with an organic solvent as described above,
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 polyimide resin composition of the present invention,
The compounding amount of the silane clay composite with respect to 100 parts by weight of the polyimide resin is typically 0.1 to 50 parts by weight, preferably 0.2 to 45 parts by weight, more preferably 0.3 to 40 parts by weight, and still more preferably. Is prepared to be 0.4 to 35 parts by weight, particularly preferably 0.5 to 30 parts by weight. If the compounding amount of the silane clay composite is less than 0.1 part by weight, the effect of improving mechanical properties and dimensional stability may be insufficient, and if it exceeds 50 parts by weight, the appearance and moldability of the molded article may be insufficient. Etc. tend to be impaired.

The ash content of the polyimide resin composition derived from the silane clay composite is typically 0.1 to 30% by weight, preferably 0.2 to 28% by weight, more preferably 0.3 to 28% by weight. It is prepared to be 25% by weight, more preferably 0.4 to 23% by weight, particularly preferably 0.5 to 20% by weight. If the ash content is less than 0.1% by weight, the effect of improving mechanical properties and dimensional stability may be insufficient, and if it exceeds 30% by weight, the appearance and formability of the molded article tend to be impaired. There is.

The structure of the silane clay composite dispersed in the polyimide resin composition of the present invention has a cohesive structure of μm size in which a number of layers are laminated, such as the swellable silicate before compounding. Completely different. That is, a silane compound having an affinity for the matrix resin is introduced, and the layers are cleaved by using a silane clay composite in which the distance between the bottom surfaces is enlarged compared to the initial swellable silicate,
Subdivide independently of each other. As a result, the silane clay composite is dispersed in a very fine and independent thin plate shape in the polyimide resin composition, and the number thereof is significantly increased as compared with the swellable silicate as a raw material. The dispersion state of such a thin silane clay composite can be expressed 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 polyimide resin composition of the present invention is defined. The average body aspect ratio is between 10 and 300, preferably between 15 and 300. More preferably, it is 20 to 300. When the average aspect ratio of the silane clay composite is less than 10, the effect of improving the elastic modulus and dimensional stability of the polyimide 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 the area of 100 μm ² of the polyimide resin composition, the silane in the polyimide resin composition of the present invention is defined as follows. 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, about 50 μm to 1 μm
On an image obtained by cutting out an ultrathin section having a thickness of 00 μm and photographing the section with a TEM or the like, the number of particles of the silane clay composite present in an arbitrary area having an area of 100 μm ² was determined by the weight of the swellable silicate used. It can be determined by dividing by a ratio. 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. Then, a value converted to an area of 100 μm 2 may be used as the [N] value. Therefore, the [N] value is the TE value of the polyimide resin composition.
It can be quantified by using an M photograph or the like. Further, when the average layer thickness is defined as a 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 polyimide resin composition of the present invention is 50
0 ° or less, preferably 450 ° or less, more preferably 400 ° or less. If the average layer thickness is more than 500 °, the effect of improving the mechanical properties and dimensional stability of the polyimide 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 °, more preferably 60 ° or more, and further preferably 70 ° 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 polyimide resin composition of the present invention, the upper limit of the maximum layer thickness of the silane clay composite is defined. The value is 2000 ° or less, preferably 1800 ° or less, more preferably 1500 ° or less. If the maximum layer thickness is more than 2000 °, the balance of mechanical properties, dimensional stability and surface properties of the polyimide 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 150 ° or more, and further preferably 200 ° or more.

The layer thickness and the layer length can be determined from an image of a thin molded product obtained by sintering the polyimide resin composition resin of the present invention using a microscope or the like.

That is, it is now assumed that the test piece prepared by the above method is placed on the XY plane. An ultra-thin section of about 50 μm to 100 μm in thickness is cut out from the above film or test piece in a plane parallel to the XZ plane or the YZ plane, and the section is cut out for about 4 to 10
It can be determined by observing at a high magnification of 10,000 times or more. The measurement was placed on the elephant of the transmission electron microscope obtained by the above method,
An arbitrary area containing 100 or more silane clay composites can be selected, imaged with an image processing device or the like, and quantified by computer processing. Alternatively, it can also be obtained by measuring using a ruler or the like.

The method for producing the polyimide resin composition of the present invention is not particularly limited. For example, (A) a step of preparing a clay dispersion containing a silane clay composite and a dispersion medium, (B) a polymerization of the polyimide resin It is preferable to use a method including a step of mixing the polymerizable prepolymer with the clay dispersion and a step of polymerizing the polymerizable prepolymer (C).

The dispersion medium used in the above step (A) means water, a polar solvent compatible with water, or a mixed solvent of water and the polar solvent.

The method for preparing the clay dispersion is not particularly limited.
For example, a method in which a system containing a dispersion medium and a silane clay composite obtained when a silane clay composite is prepared is directly used as a clay dispersion (referred to as a direct method: in this case, the silane clay composite must be prepared). Is the step (A)) or the system containing the dispersion medium and the silane clay composite obtained when the silane clay composite is prepared is mixed with another desired dispersion medium and then replaced. A method of using a system composed of a newly added desired dispersion medium and a silane clay composite as a clay dispersion (referred to as a substitution method), or a method of drying a silane clay composite obtained by removing a dispersion medium and a desired silane clay composite. For example, a method of sufficiently mixing a dispersion medium can be used. From the viewpoint of the dispersibility of the silane clay composite, the direct method and the substitution method are preferred.

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 upper limit of the 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 dispersion obtained in the step (A), the initial lamination / agglomeration structure such as that of the swellable silicate disappears almost completely and becomes a thin plate. Either it is subdivided or the interval between the layers is 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 dispersion is preferably at least three times, preferably at least four times, the initial distance between the bottom surfaces of the swellable silicate in order for the silane clay complex to be finely divided and formed into a thin plate. Is more preferable, and more preferably 5 times or more.

Next, a step (B), that is, a step of mixing the above-mentioned clay dispersion and a polymerizable prepolymer of a polyimide resin is performed. Here, the above-mentioned polymerizable prepolymer means a polymerizable monomer of the polyimide resin and / or a polymer intermediate of the polyimide resin.

The polymerizable monomer of the polyimide resin means, for example, diamine and / or acid dihydrate. As the acid anhydride, those similar to the acid anhydride constituting the polyimide resin used in the present invention are used, for example, pyromellitic dianhydride, biphenyltetracarboxylic dianhydride, benzophenonetetracarboxylic dianhydride One or more selected from materials and the like can be used. As the diamine, those similar to the diamine constituting the polyimide resin used in the present invention are used. For example, 4,4 ′
One or more selected from -diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, p-phenylenediamine, m-phenylenediamine and the like can be used.

Further, the polymerization intermediate of the polyimide resin is
It means a condensate obtained by the reaction of the polymerizable monomer and having such a viscosity that the clay dispersion containing the silane clay composite can be sufficiently uniformly dispersed. The intermediate polymer may be a homopolymer obtained by homopolymerizing the above-mentioned polymerizable monomer, or may be a copolymer composed of several kinds of monomers. It is also possible to copolymerize dicarboxylic acids, diols and derivatives thereof and use them as intermediate polymers of polyamide imide, polyester amide imide and polyester imide.

The method of mixing the clay dispersion and the polymerizable prepolymer is not particularly limited. For example, a method of batch-mixing the polymerizable prepolymer and the clay dispersion in a solution, and a method of mixing the polymerizable prepolymer in a solution state. A method of continuously adding a clay dispersion is included. In the case of continuous addition, the rate of addition of the clay dispersion is not particularly limited, but the clay dispersion is added in an amount of from 0.02 to 4.0 with respect to 100 parts by weight of the polymerizable prepolymer.
0 parts by weight / minute, preferably 0.03 to 3.8 parts by weight / minute,
More preferably, it is added continuously at 0.05 to 3.5 parts by weight / minute.

Then, the step (C), that is, the step of heating the polymerizable prepolymer or subjecting it to catalytic ring-closing polymerization may be performed.

The reason why the polyimide resin composition of the present invention is excellent in mechanical properties, dimensional stability, and surface appearance is that the silane clay composite is dispersed in the resin as a large number of fine plate-like particles. This is because 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 state, are in the ranges described above.

The dispersion state of the silane clay composite is controlled by one or more steps selected from the step of preparing the silane clay composite and the steps (A) and (B) in the above-mentioned method for producing a polyimide resin composition. obtain.

That is, for example, in the step of preparing the silane clay composite (that is, the direct method in the step (A)), if the stirring force and the shearing force in dispersing the swellable silicate are constant. For example, when the type of the dispersion medium and a plurality of types of dispersion medium are used, the swelling / cleaving state of the swellable silicate changes according to the mixing ratio and the order of mixing. 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 and tetrahydrofuran (TH
F), methyl ethyl ketone (MEK), pyridine, N,
When a mixed solvent of water and a polar solvent such as N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAc) or N-methylpyrrolidone (NMP) is used as a dispersion medium, or montmorillonite is dispersed in the polar solvent. In the case where water is added and then water is added, about several to several hundreds of unit layers are cleaved and subdivided into a laminated state. 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. Steps (A) and (B) in the method for producing a polyimide resin composition so as to maintain those states.
By performing (C) and (C), the dispersion state of the silane clay composite can be controlled.

In the substitution method (method of replacing the dispersion medium used in preparing the silane clay composite with another desired dispersion medium) in the step (A), the kind of the dispersion medium to be newly added and a plurality of kinds of dispersion mediums are used. When used, the dispersion state of the silane clay composite in the clay dispersion varies depending on the mixing ratio and the order of mixing. For example, when a polar solvent having a low affinity for the functional group of the silane-based compound is added to a water matrix dispersion containing the silane clay complex in a unit layer state and replaced with water, the silane clay complex in the unit layer state is obtained. About several to about several tens of bodies agglomerate and can be laminated. The dispersion state of the silane clay composite can be controlled by performing steps (B) and (C) in the method for producing a polyimide resin composition so as to maintain those states.

In the step (B), the dispersion state of the silane clay composite changes depending on the type and molecular weight of the polymerizable prepolymer mixed with the clay dispersion. The dispersion state of the silane clay composite can be controlled by performing the step (C) in the method for producing a polyimide resin composition so as to maintain those states.

The polyimide resin composition of the present invention may contain, if necessary, other optional resins such as polycarbonate resin, liquid crystal polyester resin, polyamide resin, polyphenylene sulfide resin, polyphenylene ether resin, polysulfone resin, and polyetherimide. Resins and thermoplastic resins such as polyarylate resins, and thermosetting resins such as epoxy resins and phenol novolak resins can be used alone or in combination of two or more.

Further, according to the purpose, the polyimide resin composition of the present invention may contain pigments and dyes, heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, lubricants, plasticizers, flame retardants,
And an additive such as an antistatic agent. The polyimide resin composition of the present invention is preferably formed by a sintering method.

Since such a molded article is excellent in appearance, mechanical properties, dimensional stability and the like, it is suitably used, for example, for precision mechanical parts, electric product parts, automobile parts, and other general industrial materials.

In the polyimide resin composition of the present invention, the silane clay composite is very fine and thinly dispersed in a plate shape, so that the surface appearance is not impaired.
The elastic modulus and dimensional stability can be improved without significantly increasing the specific gravity.

[0081]

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. (Raw materials) Tetrahydrofuran: Tetrahydrofuran (hereinafter, THF) manufactured by Wako Pure Chemical Industries, Ltd. was used. -N-methylpyrrolidone: N-methylpyrrolidone (NMP) manufactured by Wako Pure Chemical Industries, Ltd. was used. -Diamino diphenyl ether: Diamino diphenyl ether (hereinafter referred to as ODA) manufactured by Wako Pure Chemical Industries, Ltd. was used. -Pyromellitic anhydride: Pyromellitic anhydride (PMDA) manufactured by Wako Pure Chemical Industries, Ltd. was used. Montmorillonite: Natural montmorillonite from Yamagata Prefecture (bottom spacing = 13 °) was used. Swellable mica: A mixture obtained by mixing 25.4 g of talc and 4.7 g of finely pulverized sodium silicofluoride and heat-treating the mixture at 800 ° C. (bottom interval = 12 °) was used. -Γ- (2-aminoethyl) aminopropyltrimethoxysilane: manufactured by Nippon Unicar Co., Ltd., A-1120 (hereinafter A
.Gamma .- (polyoxyethylene) propyltrimethoxysilane: manufactured by Nippon Unicar Co., Ltd., A-1230 (hereinafter A)
The evaluation methods in Examples and Comparative Examples are collectively shown 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, followed by centrifugation to separate the supernatant. This washing operation was repeated three times. After washing, about 1 mg of the sufficiently dried silane clay complex and about 200 mg of KBr powder were sufficiently mixed using a mortar, and a KBr disk for measurement was prepared using a tabletop press. Next, an infrared spectrometer (Shimadzu Corporation)
, 8100M). The detector used was an MCT detector cooled with liquid nitrogen, and the resolution was 4c.
m ⁻¹ and the number of scans were 100. (Measurement of dispersion state) Regarding the silane clay composite, TE
The following procedure was performed using M.

An ultra-thin section having a thickness of 50 to 100 μm was 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 PIAS # 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 unsuitable, 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.

The aspect ratio of the dispersed particles that are not dispersed in a plate shape was a 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 °. (Bending characteristics) Approximately 10 × 100 × by press molding
A 6 mm test piece was prepared. The bending strength and the flexural modulus of the test piece of the obtained test piece were measured according to ASTM D-790. (Linear expansion coefficient) JI with a thickness of about 3mm
An S1 dumbbell-shaped test piece was used. The center part of the dumbbell-shaped test piece was cut into about 7 mm × 7 mm. SSC-5200 and TMA-1 manufactured by Seiko Electronics Co., Ltd.
After holding at 20 ° C. for 5 minutes using 20C, the temperature was raised from 20 ° C. to 300 ° C. at a rate of 5 ° C./min. 30 ~
The linear expansion coefficient in the range of 300 ° C. was calculated. (Ash content) The ash content of the polyimide resin composition derived from the silane clay composite was measured according to JIS K7052.

(Example 1) Step (A) 125 g of montmorillonite was added to 3500 g of ion-exchanged water, and the resulting mixture was mixed with a wet mill manufactured by Nippon Seiki Co., Ltd. for 500 minutes.
The mixture was stirred at 0 rpm for 5 minutes and mixed. Thereafter, 14 g of A1120 was added, and the mixture was further stirred under the conditions shown in Table 1 to prepare a silane clay composite. (Confirmation of the silane clay complex was conducted by separating, drying, and pulverizing the solid content, measuring the bottom surface interval with SAXS, and washing the product with THF to determine the absorption band of the functional group derived from the silane compound by FT-IR. The results are shown in Table 1. The same applies to Examples 2 to 4.) Then 120
0 g of NMP is added and mixed well, and then heated to remove water, that is, a clay dispersion containing a silane clay composite and NMP (ASi-Mo1 / N
MP) was prepared. The bottom spacing of the silane clay composite in the clay dispersion was> 100 °. Step (B) Clay dispersion (ASi-Mo1 / N) prepared in step (A)
MP) at 1310 g ODA and 1430 g PMD
A was mixed and dissolved. Step (C) The reaction proceeds while generating heat, and an NMP solution containing a polyamic acid and a silane clay composite, which is an intermediate polymer of polyimide, is obtained. Next, the ring closure reaction was allowed to proceed under heating to obtain a polyimide powder containing a silane clay composite. Thereafter, a polyimide molded body containing the silane clay composite was obtained by sinter molding and evaluated. The ash content and properties are shown in Table 2 together with the following examples.

(Example 2) In step (A), A11
Clay dispersion (AS
i-Mo2 / NMP) was prepared in the same manner as in Example 1 to obtain and evaluate a polyimide molded body containing a silane clay composite.

(Example 3) In the step (A), 14 g
Instead of A1120, 22 g of A1230 (previously,
Except that a clay dispersion (ESi-Mo / NMP) was prepared by a displacement method using
In the same manner as in Example 1, a polyimide molded body containing the silane clay composite was obtained and evaluated.

Example 4 In step (A), swelling mica was used in place of montmorillonite, and the amount of A1120 was 28 g.
Mi / NMP) was prepared in the same manner as in Example 1 to obtain and evaluate a polyimide molded body containing a silane clay composite. The distance between the bottom surfaces of the silane clay composite in the clay dispersion was 69 °.

Comparative Example 1 A polyimide molded body was obtained and evaluated in the same manner as in Example 1 without using the clay dispersion.

The results are shown in Table 2 together with the following comparative examples.

(Comparative Example 2) 125 g of montmorillonite and 1200 g of NMP were wet milled at 5000 rpm and 5 rpm.
The mixture was stirred and mixed for minutes to obtain a mixed solution.

A polyimide resin composition was obtained and evaluated in the same manner as in Example 1 except that the above mixture 1 was used instead of the clay dispersion ASi-Mo1 / NMP.

Comparative Example 3 14 g of A1120 was directly sprayed on 125 g of montmorillonite using a spray.
The montmorillonite was silane treated by mixing for one hour. The bottom spacing of silane treated montmorillonite is 13
After washing with THF, measurement by FT-IR showed absorption bands derived from primary amino groups, secondary amino groups, and ethylene groups.

The above-mentioned silane-treated montmorillonite and 120
0 g of NMP was stirred and mixed with a wet mill at 5000 rpm for 5 minutes to obtain a mixed solution.

A polyimide resin composition was obtained and evaluated in the same manner as in Example 1, except that the above mixture 2 was used instead of the clay dispersion ASi-Mo1 / NMP.

[0099]

As described in detail above, in the polyimide resin, the unit layers of the swellable silicate are separated and cleaved to form a very large number of aggregated particles of the swellable silicate. Subdivision into smaller lamellar layers, ie, to reduce the average layer thickness to 500 ° or less, or to reduce the maximum layer thickness to 2000 ° or less as required, or to reduce the average aspect ratio (layer length / layer thickness) Is 10 to 300,
By increasing the number of particles per unit ratio of the silane clay complex existing in the area of 100 μm ² to 30 or more, it is possible to improve dimensional stability such as improving mechanical properties and suppressing anisotropy without adversely affecting the surface appearance. Can be obtained efficiently.
In order to subdivide the swellable silicate into a thin plate as described above in the polyimide resin, it is essential to introduce a silane compound into the swellable silicate to form a silane clay composite.

The polyimide resin composition of the present invention can be produced, for example, by the production method of the present invention, that is, (A) a step of preparing a clay dispersion containing a silane clay composite and a dispersion medium, (B)
It can be obtained by a production method including a step of mixing a polymerizable prepolymer of a polyimide resin and the above clay dispersion, and a step of (C) polymerizing the polymerizable prepolymer.

[0101]

[Table 1]

[0102]

[Table 2]

[0103]

[Table 3]

Claims (7)

[Claims] 1. A polyimide resin composition containing a polyimide 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 polyimide resin composition prepared by introducing a silane compound represented by the formula (1), wherein the average 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 イ ミ ド The polyimide resin composition according to claim 1, which is: 3. A polyimide resin composition containing a polyimide resin and a silane clay composite, wherein the silane clay composite is added to 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. 4. 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 polyimide resin composition according to claim 1, which is prepared. 5. The polyimide resin composition according to claim 1, wherein the silane clay composite in the resin composition has an average aspect ratio (layer length / layer thickness ratio) of 10 to 300. 6. A step of preparing a clay dispersion containing a silane clay composite and a dispersion medium, (B) a step of mixing a polymerizable prepolymer of a polyimide resin with the clay dispersion, and (C) The method for producing a polyimide resin composition according to claim 1, which comprises a step of polymerizing a polymerizable prepolymer. 7. The method according to claim 6, wherein the bottom spacing of the silane clay complex in the clay dispersion obtained in the step (A) is at least three times the bottom spacing of the swellable silicate. A method for producing the polyimide resin composition according to the above.