JP2000109625A - Styrene resin composition and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a styrene resin compsn. not deteriorating transparency and surface appearance, and excellent in mechanical characteristics and heat deflection temp. under load. SOLUTION: This is a styrene resin compsn. contg. a styrene resin and a silane clay complex, and the silane clay complex is prepared by introducing a silane compd. represented by the formula: YnSiX4-n [wherein n is an integer of 0-3, Y is a 1-25C hydrocarbon group or an org. functional group comprising a 1-25C hydrocarbon group and a substitute group, and X is a hydrolysable group and/or a hydroxide group and n pieces of Y and (4-n) pieces of X may be the same or different kind] to a swelling silicate, and an average thickness of the silane clay complex layer in the styrene resin compsn. is not greater than 500 Å.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Styrene resins represented by polystyrene are used in various fields such as automobile parts, electric equipment parts, household goods, containers, miscellaneous goods, etc. by utilizing their transparency, dimensional stability and moldability. Although widely used, higher mechanical properties and heat resistance are required. For such purposes, various fillers, for example, glass fiber, carbon fiber, fibrous inorganic substances such as potassium titanate whiskers, glass flakes, glass beads, talc, mica, and the like are mixed with particulate inorganic substances such as kaolin. Have been. Although the mechanical properties and the like are certainly improved by the blending of the above-mentioned inorganic substances, transparency, which is a major feature of the styrene resin, is impaired, the surface appearance of the molded article is impaired, and the specific gravity is increased. Was. As another problem, there is a problem that anisotropy occurs due to the orientation of the fibrous inorganic material during injection molding.

It is generally considered that such a defect in the compounding of the fibrous inorganic substance and the particulate inorganic substance is 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 a nylon 6-based method to a styrene-based resin, styrene in which layered particles are finely dispersed is obtained. It was difficult to use a resin-based 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 obtained a composite material by incorporating layered particles in a styrene resin in a very thin plate-like structure close to the unit layer (the layer thickness of the unit layer was about 10 °). When the evaluation was carried out, the mechanical properties and the deflection temperature under load were improved, compared with those in which the layered particles were contained in the styrene-based resin in a laminated / agglomerated state by a method such as extrusion melt-kneading, It turned out that the effect was not enough.

[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 styrene-based resin composition having an excellent balance among mechanical properties, deflection temperature under load, transparency, surface properties, and specific gravity. In order to obtain a styrene 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 one swellable silicate into a very large number of extremely small sheet-like particles is obtained by being contained in a styrene-based resin, A styrene resin composition and a method for producing the same.

According to the present invention, a styrene resin composition according to claim 1 is a styrene resin composition containing a styrene resin and a silane clay composite, wherein the silane clay composite is a swellable silicate. the following general formula _{(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, in the styrenic resin composition according to the first aspect, the maximum thickness of the silane clay composite is 2000 ° or less.

The styrenic resin composition according to claim 3 is a styrenic resin composition containing a styrenic resin and a silane clay composite, wherein the silane clay composite is formed by 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 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.

The styrenic resin composition according to claim 4 is the styrenic 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 styrene resin composition according to claim 5 is the styrene 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 styrene resin composition according to claim 6 is the method for producing a styrene resin composition according to claim 1, 2, 3, 4 or 5, wherein (A) a silane clay composite. And (B) polymerizing the polymerizable monomer in the clay dispersion.

[0017] In the method for producing a styrene resin composition according to claim 7, the distance between the bottom surfaces of the silane clay composite in the clay dispersion obtained in the step (A) is as follows: It is at least three times the distance between the bottom surfaces of the swellable silicate.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The styrene resin used in the present invention is an aromatic vinyl compound or a polymer obtained by polymerizing an aromatic vinyl compound and another vinyl monomer copolymerizable therewith. .

As the aromatic vinyl compound, styrene,
α-methylstyrene, 2,4-dimethylstyrene, monochlorostyrene, dichlorostyrene, p-bromostyrene, 2,4,5-tribromostyrene, 2,4,6-tribromostyrene, p-methylstyrene, p- tert
-Butyl styrene, ethyl styrene, vinyl xylene and the like.

Other vinyl monomers copolymerizable with the aromatic vinyl compound include vinyl cyanide compounds such as acrylonitrile and methacrylonitrile, methyl acrylate, and the like.
Alkyl acrylates such as ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, and cyclohexyl acrylate; alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, 2-ethylhexyl methacrylate, and cyclohexyl methacrylate Maleimide compounds such as esters, maleimide, N-methylmaleimide, N-ethylmaleimide, N-phenylmaleimide, N-cyclohexylmaleimide, unsaturated compounds containing epoxy groups such as glycidyl methacrylate, allyl glycidyl ether, acrylic acid, methacrylic acid, itacone Acid, unsaturated acid such as maleic acid, itaconic anhydride, maleic anhydride, anhydride Unsaturated carboxylic acid anhydrides such as Torakon acid, acrylic amines, aminoethyl methacrylate, aminopropyl, amino group-containing unsaturated compounds such as amino styrene, 3-hydroxy-1 Puropen,
4-Hydroxy-1-butene, cis-Ye4e4e4e4e4e453
And hydroxy-containing unsaturated acids such as -hydroxy-2-butene, trans-4-hydroxy-2-butene, 3-hydroxy-2-methyl-1-propene, 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate, and acrylamide, vinyl oxazoline and the like. These compounds can be used alone or in combination of two or more.

Particularly preferred as the styrene resin is
Polystyrene, rubber-modified polystyrene (HIPS), and acrylonitrile-styrene copolymer (AS).

The method for producing the styrenic resin used in the present invention is not particularly limited, and the monomer component may be prepared by a known polymerization method such as emulsion polymerization, solution polymerization, suspension polymerization, bulk polymerization, or bulk suspension. It is obtained by polymerizing by a polymerization method.
At this time, the blending ratio of the aromatic vinyl monomer and other copolymerizable monomer components used as needed is not particularly limited, and each component is appropriately blended according to the use.

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, and examples thereof include smectite group clay and swellable mica. Can be When a smectite group clay and a swellable mica are used as the swellable silicate, the dispersibility of the swellable silicate in the styrenic resin composition of the present invention, the availability of the swellable silicate, and the improvement of the physical properties of the resin composition It is preferable from the point of view.

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 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 viewpoints of dispersibility in the styrene 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, but 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 compound 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” means 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 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 dimethylformamide, and other solvents such as dimethylsulfoxide and 2-pyrrolidone.

These polar solvents may be used alone.
It may be used in combination of more than one kind.

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 distance between the bottom surfaces after the enlargement is preferably 3 times or more, more preferably 5 times or more, as compared with the distance between the bottom surfaces of the initial 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. Means 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 depends on 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 styrene resin composition. It can be prepared to be sufficiently high. 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 styrenic resin composition of the present invention,
The compounding amount of the silane clay composite per 100 parts by weight of the styrene 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, furthermore The amount is preferably adjusted to 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 the mechanical properties and the deflection temperature under load may be insufficient, and if it exceeds 50 parts by weight, the transparency and surface of the molded article may be insufficient. Appearance tends to be impaired.

The ash content of the styrene resin composition derived from the silane clay composite is typically 0.1 to 30% by weight, preferably 0.2 to 28% by weight, and more preferably 0.3% by weight. To 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 the mechanical properties and the deflection temperature under load may be insufficient, and if it exceeds 30% by weight, the transparency and surface appearance of the molded article are impaired. Tend. The structure of the silane clay composite dispersed in the styrenic resin composition of the present invention is, as the swellable silicate before compounding has, a μm-sized aggregate structure in which many layers are stacked. 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 styrene-based 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 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 in the styrene resin composition of the present invention is defined as follows. The average aspect ratio of the composite is 10 to 300, 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 styrene-based resin composition of the present invention may not be able to sufficiently obtain the mechanical specialty and the effect of improving the deflection temperature under load. 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 styrene resin composition, the styrene resin composition of the present invention The [N] value of the silane clay composite in the above 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 styrenic resin composition is adjusted to about 50 μm to 1
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. The value converted to the area of 100 μm ² may be used as the [N] value. Therefore, the [N] value is the TE value of the styrenic resin composition.
It can be quantified by using an M photograph or the like.

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 styrenic resin composition of the present invention is 500 ° or less, preferably 4% or less.
It is 50 ° or less, more preferably 400 ° or less. If the average layer thickness is more than 500 °, the effect of improving the mechanical properties and the deflection temperature under load of the styrenic 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 °.
That is all.

When the maximum layer thickness is defined as the maximum value of the layer thickness of the silane clay composite dispersed in the styrenic resin composition of the present invention in the form of a thin plate, the maximum layer thickness of the silane clay composite is determined. The upper limit is 2000 ° or less, preferably 1800 ° or less, and more preferably 1500 ° or less. If the maximum layer thickness is more than 2000 °, the transparency and surface appearance of the styrene 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 20 ° or more.
0 ° or more.

The layer thickness and the layer length can be determined from an image of a thin molded product obtained from the styrene resin composition of the present invention taken with a microscope or the like.

That is, the thickness of the film prepared by the above-described method on the XY plane is about 0.5 to 0.5.
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 styrene 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 polymerizable monomer of a styrene resin; (B) a step of polymerizing the polymerizable monomer in the clay dispersion.

Here, the polymerizable monomer of the styrene resin is the same as the aromatic vinyl compound and / or vinyl monomer constituting the styrene resin used in the present invention. As the aromatic vinyl compound, for example, styrene,
α-methylstyrene, 2,4-dimethylstyrene, monochlorostyrene, dichlorostyrene, p-bromostyrene, 2,4,5-tribromostyrene, 2,4,6-tribromostyrene, p-methylstyrene, p- tert
-Butylstyrene, ethylstyrene, vinylxylene, etc., and these compounds can be used alone or in combination of two or more. As the vinyl monomer, acrylonitrile, vinyl cyanide such as methacrylonitrile, methyl acrylate, ethyl acrylate, alkyl acrylate such as butyl acrylate, methyl methacrylate, alkyl methacrylate such as ethyl methacrylate, maleimide,
Maleimide compounds such as N-methylmaleimide, N-ethylmaleimide and N-phenylmaleimide; unsaturated compounds containing epoxy groups such as glycidyl methacrylate and allyl glycidyl ether; unsaturated acids such as acrylic acid, methacrylic acid and maleic acid; and maleic anhydride Unsaturated carboxylic anhydrides such as acids, unsaturated compounds containing amino groups such as acrylamine and aminoethyl methacrylate, 3-hydroxy-1
-Propene, hydroxyl-containing unsaturated acids such as 4-hydroxy-1-butene, and acrylamide, vinyloxazoline, etc., and these compounds may be used alone or
More than one species can be used in combination.

The above-mentioned polymerizable monomer may contain a styrene-based polymer having a low degree of polymerization. The styrene-based low-polymer has a molecular weight that is obtained by radical polymerization or ionic polymerization of a polymerizable monomer of a styrene-based resin and has a viscosity such that the silane clay composite can sufficiently be uniformly dispersed. I do.

Here, the above-mentioned clay dispersion may contain an organic solvent capable of dissolving a styrene resin as a component other than the polymerizable monomer. As the organic solvent, for example, hexane, octane, decane, aliphatic hydrocarbon compounds such as hexene, cyclohexane, alicyclic hydrocarbon compounds such as cyclodecane, benzene, toluene, ethylbenzene, n-propylbenzene, cumene, t-butylbenzene, mesitylene, bromotoluene, chlorotoluene, aromatic hydrocarbon compounds such as xylene, methylene chloride, halogenated hydrocarbon compounds such as chloroform, tetrahydrofuran, dioxane, ether compounds such as methylphenyl ether, methyl ethyl ketone, Methyl allyl ketone, methyl phenyl ketone,
Ketone compounds such as cyclohexanone, ester compounds such as ethyl acetate, butyl acetate, and ethyl acetoacetate; amine compounds such as triethylamine, tri-t-butylamine, piperidine, pyridine, cyclohexylamine, aniline, and ethylenediamine; N, N-dimethylformamide; An amide compound such as N, N-dimethylacetamide;
One or more selected from the group consisting of organic solvents such as organic sulfur compounds such as dimethyl sulfoxide.

The method of preparing the clay dispersion in the above step (A) is not particularly limited. For example, a method of sufficiently mixing a silane clay composite prepared in advance and a polymerizable monomer of a styrene resin, or a method of preparing a silane clay. After sufficiently mixing the complex and the organic solvent, a method in which a polymerizable monomer is further added and mixed may be used.

For efficient mixing, a shearing speed of 500 rpm or more or a shear rate of 300 (1 / s) or more is applied. The upper limit of the number of revolutions is 25000 rp
m, and the upper limit of the shear rate is 500000 (1 / s).
It is. 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, which the swellable silicate had, had almost completely disappeared and became 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.

Then, step (B), that is, a step of polymerizing a polymerizable monomer can be performed. The polymerization method is not particularly limited, and the polymerization can be performed by a generally-used polymerization method of a styrene resin. Examples of such a method include a bulk polymerization method and a suspension polymerization method.

When another styrene-based polymerizable monomer component is copolymerized with the resin component, it can be obtained by adding and mixing a desired styrene-based polymerizable monomer at any time during the reaction to carry out the reaction.

The styrenic resin composition of the present invention can also be produced by the following method. First, a good solvent of a styrene-based resin such as benzene, toluene, dichloromethane, chlorobenzene, tetrahydrofuran (THF), methyl ethyl ketone, and ethyl acetate is sufficiently mixed with a silane clay complex prepared in advance. The number of agitation during mixing and the like are the same as those described above, and the bottom spacing of the silane clay composite after mixing is preferably at least three times, more preferably at least four times the initial bottom spacing of the swellable silicate. More preferably 5 times or more. Next, the styrene-based resin composition is obtained by adding and dissolving the styrene-based resin, thoroughly mixing and removing the solvent. The reason that the styrene-based resin composition of the present invention is excellent in mechanical properties, deflection temperature under load, and does not impair the surface appearance or transparency is that the silane clay composite in the resin is a large number of fine thin 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 dispersion state, are in the above-described ranges.

The dispersion state of the silane clay composite can be controlled by the step of preparing the silane clay composite and / or the above step (A).

Regarding the method for controlling the dispersion state of the styrene resin composition in the step of preparing the silane clay composite, the type and amount of the silane compound and the reaction conditions (reaction time) between the silane compound and the swellable silicate , Reaction temperature, stirring power), the type of the dispersion medium, and the like can be mentioned as control factors. In particular, the control is performed by the reaction time between the silane compound and the swellable silicate, the stirring power during the reaction, and the type of the dispersion medium. Is simple and preferred.

As such a method, for example, if the number of stirring and the shearing force during the reaction are constant, the type of the dispersion medium, and if a plurality of types of dispersion media are used, the mixing ratio and the order of mixing are determined. The state of swelling / cleavage of the swellable silicate changes. For example, when montmorillonite is used as the swellable silicate, if the dispersion medium is water alone, the montmorillonite swells and cleaves to a state close to the unit layer. A silane clay composite in which a silane compound has reacted for each unit layer is prepared. On the other hand, ethanol and tetrahydrofuran (TH
F), when a mixed solvent of water and a polar solvent such as methyl ethyl ketone (MEK) or N-methylpyrrolidone (NMP) is used as a dispersion medium, or when montmorillonite is dispersed in the polar solvent and then water is added, It is cleaved and subdivided into a state in which about several to several hundreds of unit layers are stacked. By reacting the silane-based compound in that state, a silane clay composite having a thickness of about several sheets to about one hundred and several tens of sheets is prepared. The dispersion state of the silane clay composite can be controlled by polymerizing the styrene resin composition so as to maintain those states.

Regarding the method of controlling the dispersion state of the styrene resin composition in the step (A), the method for controlling the affinity between the silane-clay composite constituting the clay dispersion and the polymerizable monomer and / or the organic solvent, Mixing conditions (stirring power, mixing time, temperature) of the clay complex with the polymerizable monomer and / or the organic solvent may be mentioned as control factors.
It is convenient and preferable to control by affinity, stirring power and mixing time.

As such a method, for example, when the number of stirring, the shearing force and the time during mixing are constant and styrene is used as the polymerizable monomer, the silane compound bonded to the silane clay composite is If the compound has a hydrocarbon group such as a phenyl group or a cycloalkyl group, the silane clay composite is dispersed in a unit layer to several tens of sheets because of high affinity with the polymerizable monomer. Conversely, if a silane compound having a highly polar group such as an amino group, a mercapto group or a nitrile group is reacted, about several to about one hundred and several tens of unit layers are cleaved and subdivided. The dispersion state of the silane clay composite can be controlled by polymerizing the polymerizable monomer so as to maintain those states.

The styrene resin composition of the present invention may contain, 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, copolymer of two or more α-olefins (including any copolymer such as random, block, and graft, or a mixture thereof) Alternatively, an impact modifier such as an olefin-based elastomer can be added. These may be modified with an acid compound such as maleic anhydride or an epoxy compound such as glycidyl methacrylate. In addition, other arbitrary resins, for example, a polycarbonate resin, a polyester resin, a liquid crystal polyester resin, a polyolefin resin, a polyamide resin, a polyphenylene sulfide resin, a polyphenylene ether resin, and a polyacetal as long as the properties such as mechanical properties and moldability are not impaired. Thermoplastic resins such as resins, polysulfone resins, polyimides, polyetherimide resins, and polyarylate resins, and unsaturated polyester resins, epoxy resins, and thermosetting resins such as phenol novolak resins alone or in combination of two or more. Can be used.

Further, the styrenic resin composition of the present invention may contain a pigment or 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 styrenic resin composition of the present invention may be molded by injection molding or hot press molding, and may be formed into foam beads for foaming or used in extrusion foam molding.

Further, the styrenic resin composition of the present invention
It can also be used as a film or sheet. Since such molded products and films are excellent in appearance, mechanical properties, heat resistance, etc., for example, they are used in automobile parts, household electric parts, precision machine parts, household daily necessities, packaging and container materials, and other general industrial materials. It is preferably used.

In the styrenic resin composition of the present invention, the silane clay composite is very fine and thinly dispersed in a plate shape, so that the surface smoothness is not impaired and the specific gravity is significantly increased. Without this, the mechanical properties and heat resistance can be improved.

[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 Examples and Comparative Examples are shown below. Unless otherwise specified, the raw materials were not purified.

(Raw materials, etc.) Styrene: manufactured by Wako Pure Chemical Industries, Ltd., styrene (hereinafter referred to as St)
) Was used. Acrylonitrile: Acrylonitrile (hereinafter, referred to as AN) manufactured by Wako Pure Chemical Industries, Ltd. was used. Tetrahydrofuran: Tetrahydrofuran (hereinafter, referred to as THF) manufactured by Wako Pure Chemical Industries, Ltd. was used. Reaction catalyst: Azobisisobutyronitrile (hereinafter, AIBN) 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.・ Phenyltrimethoxysilane: Shin-Etsu Silicone Co., Ltd.
LS2750 (hereinafter referred to as LS2750).・ Dodecyltriethoxysilane: Shin-Etsu Silicone Co., Ltd.
LS6570 (hereinafter, referred to as LS6570). The 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, 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. However, if necessary, the sample was melted at 250 to 270 ° 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 are not dispersed in a plate shape was a value of major axis / minor axis. Here, the long diameter means the long side of the rectangle having the smallest area among the rectangles circumscribing the target particle in a microscope image or the like. Further, the minor axis means 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 °. (Deflection temperature under load: HDT) The styrene-based resin composition was dried and injection molded to prepare a test piece having a size of about 10 × 100 × 6 mm. The deflection temperature under load of the obtained test piece,
Measured according to ASTM D-648. (Bending characteristics) The bending strength and the bending elastic modulus of the test piece prepared in the same manner as in the case of the deflection temperature under load were determined by ASTM D-
790. (Transparency) Transparency was evaluated by the haze (haze value) of a JIS No. 1 dumbbell-shaped test piece having a thickness of about 3 mm and manufactured under the same conditions as the deflection temperature under load.

The haze was measured according to JIS K7103 using a turbidity meter NDH- # 80 manufactured by Nippon Denshoku Industries Co., Ltd. (Surface Appearance) The surface appearance was evaluated by the center line average roughness of a JIS No. 1 dumbbell-shaped test piece having a thickness of about 3 mm and manufactured under the same conditions as in the case of the deflection temperature under load.

The center line surface roughness was measured using a surface roughness meter (Surfcom 1500A, manufactured by Tokyo Seimitsu Co., Ltd.). (Ash content) The ash content of the styrene 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 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, 35 g of LS2750 was added, and the mixture was further stirred under the conditions shown in Table 1 to prepare a silane-clay composite, which was dried and powdered. , And FT-
The measurement was performed by measuring the absorption band of a functional group derived from the silane compound by IR. The results are shown in Table 1. Examples 2 to 5 are similar). 100 g of the above silane clay composite and 1500 g of St are sufficiently wet milled (5000 rpm × 3).
(0 min) to prepare a clay dispersion containing the silane clay complex and St. Step (B) Clay dispersion prepared in step (A), 0.3 g AIBN
Was charged into a polymerization machine, and stirred and mixed while bubbling with nitrogen. By performing bulk polymerization at a polymerization temperature of 95 to 105 ° C for 1.5 hours, a polystyrene resin composition containing a silane clay composite was obtained and evaluated.

(Example 2) In step (A), LS2
A polystyrene resin composition containing a silane clay composite was obtained and evaluated in the same manner as in Example 1 except that the amount of 750 was changed to 25 g.

(Embodiment 3) In the step (A), LS2
Except that 35 g of LS6570 was used instead of 750 (however, stirring conditions were 5000 rpm, 2.5 hours)
Was performed in the same manner as in Example 1 to obtain and evaluate a polystyrene resin composition containing a silane clay composite.

(Example 4) Step (A) Swellable mica was used instead of montmorillonite, and LS2
The amount of 750 is 40 g (however, the stirring condition is 6000 rpm
m, 3.0 hours) to prepare a silane clay composite in the same manner as in Example 1. 125 g of the above silane clay complex and 1500 g of St were sufficiently wet milled (5000).
(rpm × 45 minutes) to prepare a clay dispersion containing the silane clay composite and St. Step (B) Bulk polymerization was performed in the same manner as in Example 1. (Example 5) Step (A) Silane clay composite 10 prepared in the same manner as in Example 1
0 g, 1125 g of St, and 375 g of AN were sufficiently mixed by a wet mill (5000 rpm × 30 minutes) to prepare a clay dispersion containing the silane clay composite and St and AN. Step (B) Clay dispersion prepared in step (A), 0.3 g AIBN
Was charged into a polymerization machine, and stirred and mixed while bubbling with nitrogen. By performing bulk polymerization at a polymerization temperature of 95 to 105 ° C for 1.5 hours, an acrylonitrile-styrene copolymer composition containing a silane clay composite was obtained and evaluated. (Comparative Example 1) Example 1 without using a silane clay composite
A polystyrene resin was obtained and evaluated in the same manner as described above. The results are shown in Table 3 together with the following comparative examples. Comparative Example 2 A polystyrene resin composition was obtained and evaluated in the same manner as in Example 1 except that 100 g of montmorillonite was used instead of the silane clay composite.

Comparative Example 3 100 g of montmorillonite was directly sprayed with 35 g of LS2750 using a spray and mixed for 1 hour to subject the montmorillonite to silane treatment. The bottom surface interval of the silane-treated montmorillonite was 13 °, and after washing with THF, as measured by FT-IR, an absorption band derived from a phenyl group was observed. A polystyrene resin composition was obtained and evaluated in the same manner as in Example 1, except that the above-mentioned silane-treated montmorillonite was used instead of the silane clay composite. (Comparative Example 4) Example 5 without using a silane clay composite
An acrylonitrile-styrene copolymer was obtained and evaluated in the same manner as described above. The results are shown in Table 3 together with the following comparative examples. (Comparative Example 5) An acrylonitrile-styrene copolymer composition was obtained in the same manner as in Example 5, except that 100 g of montmorillonite was used instead of the silane clay composite.
evaluated.

[0095]

As described in detail above, in the styrene 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 extremely thin plate-like layers, that is, an average layer thickness of 500 ° or less, or a maximum layer thickness of 2
000 ° or less, or an average aspect ratio (ratio of layer length / layer thickness) of 10 to 300 and an area of 100 μm
By setting the number of particles per unit ratio of the silane clay composite in m ² to 30 or more, the mechanical properties and the deflection temperature under load can be improved without impairing the transparency and the surface appearance. For the swellable silicate to be subdivided into a thin plate as described above in the styrene resin, it is essential to introduce a silane compound into the swellable silicate to form a silane clay composite.

The styrenic resin composition of the present invention can be produced, for example, by the method of the present invention, that is, (A) a step of preparing a clay dispersion containing a silane clay composite and a polymerizable monomer of a styrene resin; B) a step of polymerizing a polymerizable monomer in the clay dispersion.

[0097]

[Table 1]

[0098]

[Table 2]

[0099]

[Table 3]

Claims (7)

[Claims] 1. A styrenic resin composition containing a styrenic 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) (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. A styrene-based resin composition prepared by introducing a silane-based compound represented by the formula (1), wherein the silane-clay composite in the resin composition has an average layer thickness of 500 ° or less. 2. The maximum thickness of the silane clay composite is 2000.
ス チ レ ン The styrenic resin composition according to claim 1, wherein 3. A styrenic resin composition containing a styrenic resin and a silane clay composite, wherein the silane clay composite is formed 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 composite present in the area of 100 μm ² of the resin composition. Composition. 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 styrenic resin composition according to claim 1, wherein 5. The styrene-based resin composition according to claim 1, wherein the silane clay composite in the resin composition has an average aspect ratio (ratio of layer length / layer thickness) of 10 to 300. 6. A step of preparing a clay dispersion containing a silane clay composite and a polymerizable monomer of a styrene resin, and (B) a step of polymerizing the polymerizable monomer in the clay dispersion. Item 6. The method for producing a styrene resin composition according to item 1, 2, 3, 4, or 5. 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 styrene resin composition according to the above.