JP2023081543A - Polymer composite material - Google Patents

Abstract

To provide a polymer composite material that can be produced by a simple process and has excellent toughness while utilizing the good points of syndiotactic polystyrene.SOLUTION: A polymer composite material according to the present invention comprises syndiotactic polystyrene and a cyclodextrin compound, the cyclodextrin compound being at least one selected from the group consisting of cyclodextrin and cyclodextrin derivatives. A polymer composite material according to the present invention can be produced by a simple process and has excellent toughness while utilizing the good points of syndiotactic polystyrene.SELECTED DRAWING: None

Description

The present invention relates to polymeric composites.

Syndiotactic polystyrene (SPS) is known as a polymeric material that has a regular structure, facilitates intermolecular packing, and has high crystallinity. Syndiotactic polystyrene exhibits properties similar to amorphous polystyrene (aPS), such as electrical properties, low specific gravity, and low hygroscopicity, but is excellent in heat resistance, chemical resistance, and dimensional stability. Because of these features, syndiotactic polystyrene is applied to films, adhesives, coating agents, molding materials, paints, etc., and is used in fields such as electronic parts, automobile parts, and packaging materials. It is a molecular material.

Especially in recent years, there is a demand for products with higher performance and higher precision in various fields, so polymer materials are also required to have higher performance and higher functionality. R&D is also being actively carried out with respect to toughening and the like.

As one means of improving the performance of polymeric materials, a method of forming a polymeric composite material by mixing a base polymeric compound with an additive such as an inorganic filler or a rubber component is generally known. ing. In addition, for example, Patent Document 1 or Patent Document 2 relates to precise control of polymer structure using host-guest interaction by inclusion complex in order to provide a polymer material imparted with high mechanical strength. Techniques have also been proposed.

WO2016/163550 WO2018/159791

However, the method of precisely controlling the polymer structure often complicates the process for manufacturing polymer composite materials, and at present it is difficult to mass-produce them, and efficient processes have yet to be established. It is said to be ahead. From this point of view, it can be said that providing a polymer composite material that can be produced by a simple process is valuable in the industrial world. In particular, in various fields, polymer composite materials with excellent mechanical properties are in demand. There is a strong demand for molecular materials.

The present invention has been made in view of the above, and it is an object of the present invention to provide a polymer composite material that can be produced by a simple process and has excellent toughness while taking advantage of the features of syndiotactic polystyrene.

As a result of intensive studies aimed at achieving the above object, the present inventors have found that the above object can be achieved by combining a syndiotactic polystyrene and a cyclodextrin compound, and have completed the present invention. rice field.

That is, the present invention includes, for example, the subject matter described in the following sections.
Item 1
containing syndiotactic polystyrene and a cyclodextrin compound,
The polymer composite material, wherein the cyclodextrin compound is at least one selected from the group consisting of cyclodextrin and cyclodextrin derivatives.
Item 2
The syndiotactic polystyrene includes polystyrene, poly(p-methylstyrene), poly(m-methylstyrene), poly(p-tert-butylstyrene), poly(p-chlorostyrene), poly(m-chlorostyrene). , poly(p-fluorostyrene), copolymers of styrene and p-methylstyrene, copolymers of styrene and p-tert-butylstyrene, copolymers of styrene and ethylene, and copolymers of styrene and divinylbenzene Item 2. The polymer composite material according to Item 1, which is at least one selected from the group consisting of polymers.
Item 3
In the cyclodextrin derivative, the hydrogen atoms of at least one or more hydroxyl groups of the cyclodextrin are substituted with at least one group selected from the group consisting of hydrocarbon groups, acyl groups and —CONHR (where R is an alkyl group). Item 3. The polymer composite material according to Item 1 or 2, having a structure.
Item 4
Item 4. The polymer according to any one of Items 1 to 3, wherein the content of the cyclodextrin compound is 0.5 to 10% by mass with respect to the total mass of the syndiotactic polystyrene and the cyclodextrin compound. Composite material.
Item 5
Item 5. The polymer composite material according to any one of Items 1 to 4, wherein the cyclodextrin compound forms an inclusion complex.
Item 6
Item 6. The polymer composite material according to any one of Items 1 to 5, wherein in the cyclodextrin compound, the cyclodextrin is at least one selected from the group consisting of α-form, β-form and γ-form.
Item 7
Item 7. A method for producing a polymer composite material, comprising the step of producing the polymer composite material according to any one of Items 1 to 6.
Item 8
Claim 7, comprising a step A1 of obtaining a solution by stirring the syndiotactic polystyrene and the cyclodextrin compound in the presence of a solvent, and a step A2 of removing the solvent from the solution obtained in the step A1. 3. A method for producing a polymer composite material according to .
Item 9
8. The method for producing a polymer composite material according to claim 7, comprising a step B of melt-kneading the syndiotactic polystyrene and the cyclodextrin compound.

The polymer composite material according to the present invention can be produced by a simple process, and has excellent toughness while taking advantage of the features of syndiotactic polystyrene.

1 shows the measurement results of ¹ H-NMR spectra of samples prepared in Example 1 and Comparative Example 1-1. 4 shows the evaluation results of a tensile test of the polymer composite materials obtained in Examples 2 to 4 and the film obtained in Comparative Example 2. FIG. 4 shows the evaluation results of a tensile test of the polymer composite material obtained in each Example 5 and the dumbbell test piece obtained in Comparative Example 3. FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail. In this specification, the expressions "contain" and "include" include the concepts of "contain", "include", "substantially consist of" and "consist only of".

The polymeric composite material of the present invention contains syndiotactic polystyrene and a cyclodextrin compound. In the polymer composite material of the present invention, the cyclodextrin compound is at least one selected from the group consisting of cyclodextrin and cyclodextrin derivatives.

The polymer composite material of the present invention can be produced by a simple process, and has excellent toughness while taking advantage of the features of syndiotactic polystyrene.

(syndiotactic polystyrene)
Syndiotactic polystyrene (hereinafter sometimes abbreviated as SPS) is a material that is the main component of a polymer composite material, and is, so to speak, a matrix component of the polymer composite material.

In the present invention, the type of SPS is not particularly limited, and for example, known syndiotactic polystyrene can be widely applied to polymer composite materials. SPS is, for example, a styrenic polymer having a syndiotactic structure, and may include a styrenic polymer having a highly syndiotactic structure. As used herein, the term “syndiotactic” means that the phenyl rings in adjacent styrene units are arranged alternately with respect to the plane formed by the main chain of the polymer block (hereinafter referred to as syndiotacticity). It can mean that there is a high percentage of

Tacticity can be quantitatively identified by a nuclear magnetic resonance method ( ¹³ C-NMR method) using carbon isotopes. By the ¹³ C-NMR method, it is possible to quantify the abundance ratio of a plurality of consecutive structural units, for example, two consecutive monomer units as diads, three consecutive monomer units as triads, and five consecutive monomer units as pentads.

As used herein, "a styrene-based polymer having a highly syndiotactic structure" is usually 75 mol% or more, preferably 85 mol% or more in terms of racemic diad (r), or racemic pentad (rrrr) Polystyrene, poly(hydrocarbon-substituted styrene), poly(halogenated styrene), poly(halogenated alkylstyrene), poly(alkoxystyrene), which usually has syndiotacticity of 30 mol% or more, preferably 50 mol% or more, It means poly(vinyl benzoate), hydrogenated polymers or mixtures thereof, or copolymers based on these.

Poly(hydrocarbon-substituted styrene) includes poly(methylstyrene), poly(ethylstyrene), poly(isopropylstyrene), poly(tert-butylstyrene), poly(phenyl)styrene, poly(vinylnaphthalene) and poly( vinyl styrene) and the like. Examples of poly(halogenated styrene) include poly(chlorostyrene), poly(bromostyrene) and poly(fluorostyrene), and examples of poly(halogenated alkylstyrene) include poly(chloromethylstyrene). be able to. Examples of poly(alkoxystyrene) include poly(methoxystyrene) and poly(ethoxystyrene).

When the SPS is a copolymer, the comonomer components of such a copolymer include, in addition to the monomers of the above-mentioned styrenic polymers, olefin monomers such as ethylene, propylene, butene, hexene and octene; dienes such as butadiene and isoprene; Monomers; polar vinyl monomers such as cyclic olefin monomers, cyclic diene monomers, methyl methacrylate, maleic anhydride and acrylonitrile.

Among the above styrenic polymers, particularly preferred ones include polystyrene, poly(p-methylstyrene), poly(m-methylstyrene), poly(p-tert-butylstyrene), poly(p-chlorostyrene), poly( m-chlorostyrene), poly(p-fluorostyrene). Further examples include copolymers of styrene and p-methylstyrene, copolymers of styrene and p-tert-butylstyrene, copolymers of styrene and divinylbenzene, copolymers of styrene and ethylene, and the like. can.
When the copolymer is used, for example, the content of p-methylstyrene in the copolymer of styrene and p-methylstyrene is 1 to 50 mol%, 1 to 40 mol%, 1 to 30 mol%, or 1 to 20 mol%. and the content of ethylene in the copolymer of styrene and ethylene is preferably 1 to 50 mol %, 1 to 40 mol %, 1 to 30 mol %, or 1 to 20 mol %.

The molecular weight of the SPS is not particularly limited, but from the viewpoint of the fluidity of the resin during molding and the mechanical properties including the toughness of the resulting molded product, the weight-average molecular weight should be 1×10 ⁴ or more and 1×10 ⁶ or less. preferably 50,000 or more and 500,000 or less, even more preferably 50,000 or more and 300,000 or less. If the weight average molecular weight is 1×10 ⁴ or more, a molded article having excellent toughness and sufficient mechanical properties can be obtained. On the other hand, if the weight average molecular weight is 1×10 ⁶ or less, there is no problem with the fluidity of the resin during molding. The weight average molecular weight (Mw) of SPS referred to in this specification is a polystyrene-equivalent value obtained by gel permeation chromatography (GPC) measurement.

The SPS has an MFR measurement value of, for example, 2 g/10 minutes or more, preferably 4 g/10 minutes or more, under conditions of a temperature of 300° C. and a load of 1.2 kgf. When the MFR measurement value of SPS is within the above range, there is no problem with the fluidity of the resin during molding. In addition, the SPS has an MFR measurement value of, for example, 50 g/10 minutes or less, preferably 30 g/minute or less, and in these ranges, it has excellent toughness and sufficient mechanical properties. It is possible to obtain a molded article having

SPS can be produced, for example, by a known method. SPS can be produced, for example, by referring to the technique disclosed in Japanese Patent Application Laid-Open No. 62-187708. Specifically, a predetermined styrenic monomer is polymerized in an inert hydrocarbon solvent or in the absence of a solvent, using a titanium compound and a condensation product of water and trialkylaluminum as a catalyst. can be manufactured. When the SPS is poly(halogenated alkylstyrene), it is produced by the method described in JP-A-1-146912, and its hydrogenated polymer is produced by the method described in JP-A-1-178505. be able to.

The SPS contained in the polymer composite material of the present invention can be one type alone or two or more types.

(Cyclodextrin compound)
The cyclodextrin compound contained in the polymer composite material of the present invention is, as described above, at least one selected from the group consisting of cyclodextrin and cyclodextrin derivatives.

Cyclodextrins include α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin. Similarly, cyclodextrin derivatives include α-cyclodextrin derivatives, β-cyclodextrin derivatives and γ-cyclodextrin derivatives. That is, in the cyclodextrin compound, the cyclodextrin can be at least one selected from the group consisting of α-, β- and γ-isomers.

When the cyclodextrin compound is α-form (that is, when it is α-cyclodextrin or an α-cyclodextrin derivative), the polymer composite material of the present invention tends to have high breaking strain, and therefore tends to have excellent mechanical properties. It is easy to improve toughness. In addition, when the cyclodextrin compound is in the β form (that is, when it is β-cyclodextrin or a β-cyclodextrin derivative), the polymer composite material of the present invention tends to have high rigidity.

As used herein, the cyclodextrin derivative means, for example, a compound in which at least one or more hydrogen atoms of hydroxyl groups of cyclodextrin are substituted with other substituents. The type of such substituent is not particularly limited, and for example, a wide range of monovalent groups capable of substituting the hydrogen atom of the hydroxyl group of cyclodesquitrin can be applied. Substituents include various hydrophobic groups, among which hydrocarbon groups, acyl groups and --CONHR (R is an alkyl group) are preferred.

Therefore, when the cyclodextrin compound is a cyclodextrin derivative, the cyclodextrin derivative has at least one hydrogen atom of a hydroxyl group of the cyclodextrin that is a hydrocarbon group, an acyl group, or -CONHR (R is an alkyl group). It is preferred to have a structure substituted with at least one group selected from the group consisting of. In this case, the toughness of the polymer composite material is likely to be further improved, and the excellent features of SPS, especially the excellent heat resistance, solvent resistance and dimensional stability of SPS can be maintained.

The type of the hydrocarbon group is not particularly limited, and examples thereof include alkyl groups, alkenyl groups, and alkynyl groups. The number of carbon atoms in the hydrocarbon group is not particularly limited, and is preferably 1 to 4, for example. Specific examples of hydrocarbon groups having 1 to 4 carbon atoms include methyl, ethyl, propyl and butyl groups. When the hydrocarbon group is a propyl group or a butyl group, it may be linear or branched.

The type of acyl group is not particularly limited, and examples thereof include acetyl group, propionyl group, formyl group and the like, and the acyl group is preferably acetyl group.

—CONHR (R is a methyl group or an ethyl group) includes, for example, a methyl carbamate group, an ethyl carbamate group, and the like, preferably an ethyl carbamate group.

The cyclodextrin derivative preferably has a structure in which 70% or more of the hydrogen atoms of the hydroxyl groups out of the total number of hydroxyl groups present in one cyclodextrin molecule are substituted with the substituents, and 80% or more of the hydrogen atoms of the hydroxyl groups It is more preferable to have a structure in which atoms are substituted with the substituent, more preferably have a structure in which 90% or more of the hydrogen atoms of the hydroxyl groups are substituted with the substituent, and all the hydrogen atoms of the hydroxyl groups are substituted with the substituent. It is particularly preferred to have a structure substituted with a group.

In the polymer composite material of the present invention, the cyclodextrin compound is preferably the cyclodextrin derivative. In this case, as will be described later, an inclusion complex between the SPS and the cyclodextrin compound is likely to be formed, so the toughness of the polymer composite material is likely to be improved. Among them, in the cyclodextrin derivative, the substituent is more preferably an alkyl group having 1 to 4 carbon atoms or an acyl group, more preferably a methyl group or an acetyl group.

The cyclodextrin compound is more preferably an α-cyclodextrin derivative from the viewpoint of increasing the breaking strain of the polymer composite material of the present invention and improving the toughness. In this case, the substituent in the α-cyclodextrin derivative is more preferably an alkyl group having 1 to 4 carbon atoms or an acyl group, particularly preferably a methyl group or an acetyl group.

Moreover, from the viewpoint of improving the rigidity of the polymer composite material of the present invention, the cyclodextrin compound is more preferably a β-cyclodextrin derivative. In this case, the substituent in the β-cyclodextrin derivative is more preferably an alkyl group having 1 to 4 carbon atoms or an acyl group, particularly preferably a methyl group or an acetyl group.

The cyclodextrin compound contained in the polymer composite material of the present invention may be one type alone, or two or more different types.

A cyclodextrin compound can be produced by a known method, or can be obtained from a commercial product. When the cyclodextrin compound is a cyclodextrin derivative, for example, the cyclodextrin compound can be produced by a known method using cyclodextrin as a raw material (eg, International Publication No. 2018/159791).

For example, as a method for substituting a hydrocarbon group for a hydrogen atom of a hydroxyl group present in cyclodextrin, a wide range of known alkylation reactions can be employed. As a method for substituting a hydrogen atom of a hydroxyl group present in cyclodextrin with an acyl group such as an acetyl group, for example, a widely known acylation reaction can be adopted. Another example of a method for substituting an acetyl group for a hydrogen atom of a hydroxyl group present in cyclodextrin is acetylation using a solvent capable of trapping an acid such as pyridine in the presence of acetic anhydride or isopropyl acetate. method. A widely known alkyl carbamate reaction can be adopted as a method for substituting —CONHR (R is a methyl group or an ethyl group) for a hydrogen atom of a hydroxyl group present in cyclodextrin.

In addition, since the cyclodextrin compound contained in the polymer composite material of the present invention does not have a radically polymerizable functional group, the cyclodextrin compound can be produced by a simple method. A molecular composite material can be produced easily.

(polymer composite material)
In the polymer composite material of the present invention, the content ratio of SPS (syndiotactic polystyrene) and cyclodextrin compound is not particularly limited, but SPS is the main component in that the polymer composite material tends to exhibit excellent toughness. Preferably.

Specifically, in the polymer composite material, the content of the cyclodextrin compound is preferably 0.5 to 10% by mass with respect to the total mass of the SPS and the cyclodextrin compound. In this case, the polymer composite material tends to have excellent toughness while maintaining the features of syndiotactic polystyrene (in particular, heat resistance, solvent resistance and dimensional stability). The content of the cyclodextrin compound is more preferably 0.7% by mass or more, more preferably 0.8% by mass or more, relative to the total mass of the SPS and the cyclodextrin compound, and It is more preferably 6 mass or less, still more preferably 5 mass or less, even more preferably 4.5 mass or less, and particularly preferably 4 mass or less. In particular, when the content of the cyclodextrin compound is 0.5 to 4% by mass, the toughness of the polymer composite material tends to be remarkably improved.

The polymer composite material of the present invention can contain other components as additives in addition to the SPS and the cyclodextrin compound as long as the effects of the present invention are not impaired. Such other components include, for example, light stabilizers, antioxidants, crystal nucleating agents, preservatives, surfactants, fillers such as inorganic particles, flame retardants, pigments, colorants, antifungal agents, lubricants, and the like. mentioned. The content ratio of the other component is also not particularly limited. For example, 20 parts by mass or less, preferably 15 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 5 parts by mass or less, and particularly preferably 1 part by mass or less per 100 parts by mass of the total mass of the SPS and the cyclodextrin compound. can be The polymeric composite material of the present invention may consist of SPS and cyclodextrin compound only.

In the polymer composite material of the present invention, the mixed state of the polymer component and the cyclodextrin compound is not particularly limited. may be present. For example, the polymeric composites of the present invention can form islands-in-the-sea structures. The form of the sea-island structure is not particularly limited, and examples thereof include a form in which spherical islands are dispersed in a matrix (sea). When the islands are spherical, their average diameter is not particularly limited, and can be, for example, 0.5 to 100 μm, preferably 1 to 50 μm, more preferably 2 to 10 μm. The average diameter of the islands refers to the value obtained by measuring the equivalent circle diameters of five randomly selected islands by direct observation of the polymer composite material with a scanning electron microscope and arithmetically averaging them.

In particular, in the polymer composite material of the present invention, the cyclodextrin compound preferably forms an inclusion complex. This makes it easier for the polymer composite material to further improve toughness while maintaining the features of syndiotactic polystyrene (in particular, heat resistance, solvent resistance and dimensional stability). The cyclodextrin compound can, for example, include aromatic rings attached to the main chain of syndiotactic polystyrene, thereby forming the inclusion complex.

It should be noted that the fact that the ^cyclodextrin compound forms an inclusion complex can be confirmed by various methods. The presence or absence of inclusion complex formation can be determined from the change in chemical shift based on the cyclodextrin compound.

Although this is not necessarily intended to be a restrictive interpretation, the presence of the inclusion complex in the polymer composite material of the present invention forms a so-called host-guest interaction. It can be inferred that both are strongly bound together as they are dispersed, thereby improving the toughness of the polymer composite material. As described above, when the polymer composite material forms a sea-island structure, the interphase separation between the sea portion and the island portion is strongly bonded, so that interphase separation is less likely to occur, and the toughness can be improved.

In conventional polymer composite technology, etc., unless a large amount of filler is added for the purpose of improving strength, the purpose of the present invention cannot be achieved in many cases. It makes it possible to remarkably improve the toughness even without containing it (for example, by adding it in the above-mentioned content ratio). One of the reasons for this is presumed to be the formation of host-guest interaction due to the presence of the inclusion complex.

The polymeric composites of the present invention can have a melting point lower than that of SPS. For example, when SPS is a homopolymer of polystyrene, the melting point is generally about 270° C., but the polymer composite material of the present invention has a melting point lower than this because it contains the cyclodextrin compound. Further, for example, when the SPS is a copolymer of styrene and p-methylstyrene, it is possible to lower the melting point of the polystyrene homopolymer by controlling the copolymerization ratio. However, the polymer composite material of the present invention has a melting point lower than these by containing the cyclodextrin compound.

Since the polymer composite material of the present invention can exist in the SPS with the cyclodextrin compound forming an inclusion complex, the polymer composite material of the present invention further has a melting point lower than that of the SPS. It seems to have Specifically, when the cyclodextrin compound is contained, a crystal based on an inclusion complex is generated, and interaction points between SPS crystals are less likely to be formed, resulting in a lower melting point than the SPS crystal. It is speculated that

From this, it can be said that the melting point can be adjusted by including the cyclodextrin compound in the SPS. By adjusting the melting point to lower the melting point, for example, the options for usable additives, solvents, etc. can be increased.

The shape of the polymer composite material is not particularly limited, and for example, it can be formed into an appropriate molded body according to the desired application. For example, the polymer composite material can have various shapes such as plate-like, film-like, sheet-like, block-like, powdery, granular, pellet-like, fiber-like, paste-like, and clay-like.

A method for molding the polymer composite material of the present invention is not particularly limited, and for example, a wide range of known molding methods can be employed. For example, a molded body having a desired shape can be obtained by a known molding means using a polymer composite material in the form of powder, pellets, or the like.

The method for producing the polymer composite material is not particularly limited as long as it includes the step of producing the polymer composite material. For example, the polymer composite material is produced using the syndiotactic polystyrene and the cyclodextrin compound. method can be adopted. Specifically, a method of using a solution or dispersion containing SPS and a cyclodextrin compound, a method of melting and mixing SPS and cyclodextrin, and a composite obtained using a solution or dispersion containing SPS and cyclodextrin A polymer composite material can be obtained by a method of melting and kneading materials and molding them.

Various organic solvents can be widely used when a solvent is used in the method for producing a polymer composite material. For example, the organic solvent includes chlorinated hydrocarbons such as chloroform and 1,2-dichloroethane; ether compounds such as diethyl ether and tetrahydrofuran; aliphatic hydrocarbons such as hexane and heptane; alicyclic hydrocarbons such as cyclohexane; , toluene, xylene, trichlorobenzene and other aromatic compounds; acetone, methyl ethyl ketone, ethyl ethyl ketone, butyl ethyl ketone, diethyl ketone, dibutyl ketone and other ketone compounds; vinyl acetate and other ester compounds; methanol, ethanol, isopropyl alcohol and t alcohols such as -butanol; formamides such as N,N-dimethylformamide and N,N-dimethylacetamide; pyrrolidones such as 2-pyrrolidone and N-methylpyrrolidone; Among these organic solvents, chloroform, 1,2-dichloroethane, tetrahydrofuran, toluene, xylene, trichlorobenzene, methyl ethyl ketone, ethyl ethyl ketone, butyl ethyl ketone, diethyl ketone, dibutyl ketone, vinyl acetate, N,N-dimethylformamide, N,N-dimethylacetamide, 2-pyrrolidone, N-methylpyrrolidone and dimethylsulfoxide can be preferably used.

The method of forming the polymer composite material from the solution or dispersion containing the SPS and the cyclodextrin compound is not particularly limited, and examples thereof include various film forming methods such as known casting methods and coating methods. In addition, a film-like polymer composite material can be directly obtained by a method of pouring the solution or dispersion into a mold having a predetermined shape and then evaporating volatile matter by an appropriate method to form a film.

One embodiment of the method for producing a polymer composite material includes a production method (hereinafter referred to as production method 1) including the following steps A1 and A2.
Step A1: A step of stirring the syndiotactic polystyrene and the cyclodextrin compound in the presence of the solvent to obtain a solution Step A2: A step of removing the solvent from the solution obtained in the step A1.

In step A1, the temperature for preparing the solution is not particularly limited, and for example, room temperature to 300°C is preferable, 100 to 150°C is preferable, and 120 to 200°C is more preferable. The method for preparing the solution is not particularly limited, and for example, the solution can be prepared by known stirring means or mixing means. Additives such as known antioxidants can also be added when preparing the solution.

In the step A2, the method of removing the solvent is not particularly limited, either, and for example, widely known drying means can be employed. Drying conditions can also be carried out under appropriate conditions depending on the boiling point of the solvent and the like.

By the production method 1 including the steps A1 and A2, for example, a film-like or sheet-like polymer composite material can be obtained.

Further, as another embodiment of the method for producing a polymer composite material, a production method comprising the following step B (hereinafter referred to as production method 2) can be mentioned.
Step B: A step of melt-kneading a syndiotactic polystyrene and a cyclodextrin compound.

In step B, the melt-kneading method is not particularly limited, and a wide range of known melt-kneading methods can be employed, and the kneading can be performed using a known melt-kneader. The conditions for melt-kneading are not particularly limited, for example, the melting temperature, the screw rotation speed of the melt-kneader, the kneading time, etc. are also not particularly limited, and can be in the same range as known melt-kneading conditions using SPS. . Also, an antioxidant, a crystal nucleating agent, and other additives may be added during the melt-kneading.

By performing melt-kneading in step B, for example, a pellet-shaped product can be obtained, and after post-treatment such as drying as necessary, molding is performed to obtain a polymer composite material having a desired shape. Obtainable.

In the method for producing a polymer composite material including the production method 1 and production method 2, the proportion of SPS and the cyclodextrin compound used is not particularly limited. For example, the proportion of the cyclodextrin compound used in the production of the polymer composite material is preferably 0.5 to 10% by mass with respect to the total mass of the SPS and the cyclodextrin compound. In this case, the obtained polymer composite material tends to have excellent toughness while maintaining the features of syndiotactic polystyrene (in particular, heat resistance, solvent resistance and dimensional stability). The proportion of the cyclodextrin compound used is more preferably 0.7% by mass or more, more preferably 0.8% by mass or more, relative to the total mass of the SPS and the cyclodextrin compound, and It is more preferably 6 mass or less, still more preferably 5 mass or less, even more preferably 4.5 mass or less, and particularly preferably 4 mass or less. In particular, when the proportion of the cyclodextrin compound used is 0.5 to 4% by mass, the toughness of the obtained polymer composite material tends to be remarkably improved.

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the embodiments of these examples.

(Example 1; Preparation of sample for NMR measurement)
SPS-1 (a copolymer of styrene and p-methylstyrene, p-methylstyrene content of 7.5 mol%, MFR 14.0 g/10 min) and hydrogen of all hydroxyl groups of β-cyclodextrin as a cyclodextrin compound A compound having an atom substituted with an acetyl group (hereinafter sometimes abbreviated as “AcβCD”) was prepared. AcβCD was produced by a known method. Specifically, AcβCD was produced by a method of reacting β-cyclodextrin and acetic anhydride in the presence of pyridine. A 5.2 mg/ml deuterated chloroform solution of the SPS-1 and a 100.9 mg/ml deuterated chloroform solution of the AcβCD were prepared, and each solution was used to express SPS-1/AcβCD. Various samples were prepared with solution volume ratios of 90/10, 80/20, 70/30, 60/40, 50/50, 40/60, 30/70, 20/80 and 10/90. The heavy chloroform used in the heavy chloroform solution was 99.8% deuterated chloroform manufactured by Sigma-Aldrich Co., to which 0.03 vol % of tetramethylsilane was added. ¹ H-NMR spectra were measured using the various samples described above. The NMR measurement was performed using ECA500 manufactured by JEOL RESONANCE, and the analysis was based on the peak of tetramethylsilane at 0 ppm.

(Comparative Example 1-1)
Samples were prepared in the same manner as in Example 1, except that the solution volume ratio represented by SPS-1/AcβCD was changed to 100/0 and 0/100.

FIG. 1 shows the measurement results of ¹ H-NMR spectra of the samples prepared in Example 1 and Comparative Example 1-1. ^{The 1} H-NMR spectrum confirms that the peak at 6.44 ppm measured in the sample with a ratio of SPS-1/AcβCD of 100/0 increases in chemical shift value as the ratio of SPS-1 decreases. was done. It was also confirmed that the chemical shift values of some other peaks changed according to the change of the SPS-1/AcβCD ratio. This change in spectrum confirmed the formation of an inclusion complex between the cyclodextrin compound and the aromatic ring of SPS.

In the same manner, instead of AcβCD used in Example 1 as a cyclodextrin compound, a compound (hereinafter abbreviated as “AcαCD”) in which all hydrogen atoms of hydroxyl groups of α-cyclodextrin were substituted with acetyl groups was used. or a compound in which all the hydrogen atoms of the hydroxyl groups of γ-cyclodextrin are substituted with acetyl groups (hereinafter abbreviated as "AcγCD"), a spectral change similar to that shown in Fig. 1 was confirmed. was done. Therefore, it was confirmed that any of the α-, β-, and γ-cyclodextrin compounds formed an inclusion complex with the aromatic ring of SPS.

Both AcαCD and AcγCD were produced by known methods. Specifically, AcβCD was produced by a method of reacting α-cyclodextrin or γ-cyclodextrin with acetic anhydride in the presence of pyridine.

(Example 2-1)
The SPS-1 and the AcαCD were prepared. SPS and AcαCD produced as described above were weighed so that the mass ratio was 99:1 (SPS:AcαCD). Chlorobenzene (TCB) was added to a concentration of 10 mg/mL. The vial was covered with aluminum foil and left standing in this state in an oil bath at 180° C. for 3 hours while stirring to obtain a solution. The hot solution thus obtained was immediately poured into a glass petri dish, allowed to cool naturally for 30 minutes, and then left to stand in a convection oven at 180° C. for 2 hours together with the glass petri dish for drying. As a result, a film-like polymer composite material having a thickness of 0.1 mm was obtained.

(Example 2-2)
A film-like polymer composite material having a thickness of 0.1 mm was obtained in the same manner as in Example 2-1, except that the mass ratio of SPS and AcαCD was changed to 97:3 (SPS:AcαCD). rice field.

(Example 3-1)
A film-like polymer composite material having a thickness of 0.1 mm was obtained in the same manner as in Example 2-1, except that AcβCD was used instead of AcαCD as the cyclodextrin compound.

(Example 3-2)
A film-like polymer composite material having a thickness of 0.1 mm was obtained in the same manner as in Example 3-1, except that the mass ratio of SPS and AcβCD was changed to 97:3 (SPS:AcβCD). rice field.

(Example 4-1)
A film-like polymer composite material having a thickness of 0.1 mm was obtained in the same manner as in Example 2-1, except that AcγCD was used instead of AcαCD as the cyclodextrin compound.

(Example 4-2)
A film-like polymer composite material having a thickness of 0.1 mm was obtained in the same manner as in Example 4-1, except that the mass ratio of SPS and AcγCD was changed to 97:3 (SPS:AcγCD). rice field.

(Comparative example 2)
A film-like polymer composite material for comparison was obtained in the same manner as in Example 1-1 except that AcβCD was not used (that is, a film-like polymer composite material was obtained only with SPS).

(Example 5-1)
SPS-2 (polystyrene homopolymer, MFR 13.0 g/10 min) and AcβCD, which is a cyclodextrin compound, were blended in a mass ratio of 99:1 (SPS-2:AcβCD) and dry-blended to obtain a resin mixture. rice field. Subsequently, using an Xplore MC 15HT small kneader (manufactured by Xplore Instruments), the barrel temperature is 300 ° C., the screw rotation speed is 50 rpm, and the kneading time is 3 minutes. Polymer composite materials were molded using an injection molding machine (manufactured by Xplore Instruments). The molding was carried out under conditions of a cylinder temperature of 300°C and a mold temperature of 150°C. As the molding, dumbbell test piece type A12, which is 1/2 scale of dumbbell test piece type A1 in accordance with ISO527-1,2:2012, was produced.

(Example 5-2)
A dumbbell test piece type A12 was produced in the same manner as in Example 5-1, except that the mass ratio of SPS-2 to AcβCD (SPS-2:AcβCD) was changed to 97:3.

(Example 5-3)
A dumbbell test piece type A12 was produced in the same manner as in Example 5-1, except that the mass ratio of SPS-2 to AcβCD (SPS-2:AcβCD) was changed to 94:6.

(Comparative Example 3)
Dumbbell test piece type A12 for comparison was obtained in the same manner as in Example 5-1 except that AcβCD was not used (that is, dumbbell test piece type A12 was obtained only with SPS).

(Evaluation of toughness of film polymer composite material)
The toughness of the film-like polymer composite materials obtained in Examples 2 to 4 was evaluated by the following tensile test. For this tensile test, a "stroke-test force curve" test (manufactured by Shimadzu Corporation "AUTOGRAPH" (model number: AGX-plus) was used, and a tensile speed of 0.1 mm/s at room temperature (uniaxial elongation until breakage. Record the stress change) to observe the breaking point of the sample.In addition, with this breaking point as the end point, the maximum stress to the end point is the breaking stress of the sample.This tensile test is performed at the lower end of the polymer material was fixed and the upper end was pulled at a speed of 0.1 mm / s.In addition, the stroke at that time, that is, the maximum length when the specimen was pulled, was divided by the specimen length before tension The resulting value was calculated as an elongation rate (which may also be referred to as a strain rate), and as a result, a stress-strain curve shown in Fig. 2 was obtained.

FIG. 2 shows the evaluation results of the tensile test of the polymer composite materials obtained in Examples 2 to 4 and the film obtained in Comparative Example 1. Specifically, FIG. 2(a) shows tensile tests of the polymer composite materials obtained in Examples 2-1 and 2-2 and Comparative Example 1, and FIG. 2(b) shows Examples 3-1 and 3. -2, tensile test of the polymer composite material obtained in Comparative Example 1, FIG. 1 shows stress-strain curves obtained from testing.

(Evaluation of toughness of polymer composite material with dumbbell specimen shape)
FIG. 3 shows the results of tensile nominal strain measurement using the dumbbell test pieces obtained in Examples 5-1 to 5-3 and Comparative Example 3. The measurement was performed in accordance with ISO 527-1, 2:2012 using an INSTRON5567 (a universal testing machine manufactured by INSTRON) under the conditions of room temperature, chuck distance of 57.5 mm, and tensile speed of 1 mm/min.

From the results of FIGS. 2 and 3, it was found that the polymer composite material containing syndiotactic polystyrene and a cyclodextrin compound is a material with excellent toughness while making the most of the features of syndiotactic polystyrene.

Claims (9)

containing syndiotactic polystyrene and a cyclodextrin compound,
The polymer composite material, wherein the cyclodextrin compound is at least one selected from the group consisting of cyclodextrin and cyclodextrin derivatives. The syndiotactic polystyrene includes polystyrene, poly(p-methylstyrene), poly(m-methylstyrene), poly(p-tert-butylstyrene), poly(p-chlorostyrene), poly(m-chlorostyrene). , poly(p-fluorostyrene), copolymers of styrene and p-methylstyrene, copolymers of styrene and p-tert-butylstyrene, copolymers of styrene and ethylene, and copolymers of styrene and divinylbenzene The polymer composite material according to claim 1, which is at least one selected from the group consisting of polymers. In the cyclodextrin derivative, the hydrogen atoms of at least one or more hydroxyl groups of the cyclodextrin are substituted with at least one group selected from the group consisting of hydrocarbon groups, acyl groups and —CONHR (where R is an alkyl group). The polymer composite material according to claim 1 or 2, having a structure of The content of the cyclodextrin compound is 0.5 to 10% by mass with respect to the total mass of the syndiotactic polystyrene and the cyclodextrin compound, the high content of any one of claims 1 to 3 molecular composites. The polymer composite material according to any one of claims 1 to 4, wherein the cyclodextrin compound forms an inclusion complex. The polymer composite material according to any one of claims 1 to 5, wherein in the cyclodextrin compound, the cyclodextrin is at least one selected from the group consisting of α-form, β-form and γ-form. A method for producing a polymer composite material, comprising the step of producing the polymer composite material according to any one of claims 1 to 6. Claim 7, comprising a step A1 of obtaining a solution by stirring the syndiotactic polystyrene and the cyclodextrin compound in the presence of a solvent, and a step A2 of removing the solvent from the solution obtained in the step A1. 3. A method for producing a polymer composite material according to . 8. The method for producing a polymer composite material according to claim 7, comprising a step B of melt-kneading the syndiotactic polystyrene and the cyclodextrin compound.

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