JP2023030683A - Styrenic resin composition, and production method of styrenic resin composition - Google Patents

Abstract

To provide a styrenic resin composition excellent in low odor, moldability, and appearance, and a production method thereof.SOLUTION: The styrenic resin composition contains: 49.6-98.6 mass% of a polystyrene component (A) containing a styrenic resin; 1-50 mass% of a polyphenylene ether component (B) containing a modified polyphenylene ether resin with a terminal group represented by the general formula (I) in the figure; and 0.4 mass% or less of an oligomer component (C) containing a styrene oligomer.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a styrenic resin composition and a method for producing a styrenic resin composition.

Styrene-based resins are used in a wide range of applications due to their excellent moldability, dimensional stability, and impact resistance. Among others, a technique related to a polymer alloy of a styrene-based resin and a polyphenylene ether-based resin having excellent high-frequency characteristics, flame retardancy, and heat resistance is one of the systems that have been extensively studied.
For example, Patent Literature 1 discloses a technique related to an alloy of a polyphenylene ether-based resin and a styrene-based resin. Specifically, a low odor polyphenylene ether/polystyrene material is produced by a process that includes passing a solution containing a polyphenylene ether-based resin and a styrenic resin through a volatile removal zone to reduce the content of odorous impurities in the product. A method of making is described. Further, in Patent Document 2, a low odor polyphenylene ether system containing polyphenylene ether, a styrene resin, and alumina containing transition alumina as a main component and having a median particle size of 150 μm or less and a BET surface area of 10 m ² /g or more A resin composition is described.

JP-A-2-215856 JP-A-8-143764

As described in Patent Documents 1 and 2 above, when producing or processing a polyphenylene ether-based resin, odors are generated due to components derived from the polyphenylene ether-based resin, so the odor of the indoor workplace where the production or processing is performed is ventilated outdoors. There is a problem that it must be discharged to. Therefore, in the technique of Patent Document 1, odorous impurities are reduced by devolatilizing a solution containing a polyphenylene ether-based resin. On the other hand, the technique of Patent Document 2 reduces odor by adsorbing odorous impurities on alumina.
However, the techniques of Patent Documents 1 and 2 do not address the new problem that a large amount of decomposed products are generated in the process of producing a low-odor polyphenylene ether/polystyrene material, resulting in deterioration of the appearance of molded articles.
Accordingly, an object of the present invention is to provide a styrenic resin composition having low odor, moldability and excellent appearance, and a method for producing the same.

In order to achieve the above object, the present inventors have made intensive studies and found that a composition containing a styrene resin and a specific polyphenylene ether resin has low odor, moldability, and appearance. The inventors have found that an excellent resin composition and a method for producing the same can be obtained, and have completed the invention.

（上記一般式（Ｉ）中、Ｒ^１は、水素原子、ハロゲン原子、又は炭素原子数１～４のアルキル基を表し、Ｒ^２は、置換基Ｌにより置換される又は無置換のフェニル基、－ＣＯＯ－Ｒ^６（Ｒ^６は、炭素原子数１～８のアルキル基）、又はニトリル基を表し、Ｒ^３、Ｒ^４及びＲ^５はそれぞれ独立して、水素原子又は炭素原子数１～３のアルキル基を表し、置換基Ｌは、炭素原子数１～４のアルキル基を表し、当該炭素原子数１～４のアルキル基中の１以上の水素原子はハロゲン原子に置換されてもよい。但し、Ｒ^３及びＲ^４が同時にメチル基となることはない。）
で表される基を末端に有する改質ポリフェニレンエーテル系樹脂を含むポリフェニレンエーテル成分（Ｂ）１～５０質量％と、
スチレンオリゴマーを含むオリゴマー成分（Ｃ）０．４質量％以下と、を含有する、スチレン系樹脂組成物である。
〔２〕本発明において、前記改質ポリフェニレンエーテル系樹脂の化学式（Ｉ）で表される末端構造は、前記ポリフェニレンエーテル成分（Ｂ）全体の主鎖構造１０００単位に対して、０．５単位以上１０単位以下含むことが好ましい。
〔３〕本発明に係るスチレン系樹脂組成物の製造方法は、ポリスチレン成分（Ａ）と、末端にイミノ基を有する改質ポリフェニレンエーテル系樹脂を含むポリフェニレンエーテル成分（Ｂ）と、芳香族ビニル系化合物と、を含む配合物を、６０℃以上２５０℃以下の温度範囲で加熱溶融して溶融物を調製する工程（Ｉ）と、
前記配合物又は前記溶融物を２００℃以上２５０℃以下の温度条件で脱揮する工程（ＩＩ）と、を有する。
〔４〕本発明に係るスチレン系樹脂組成物の製造方法おいて、前記芳香族ビニル系化合物を、ポリフェニレンエーテル成分（Ｂ）の添加量１００重量部に対し、１～１０００重量部添加することが好ましい。
〔５〕本発明に係るスチレン系樹脂組成物の製造方法おいて、前記配合物は、予め前記ポリフェニレンエーテル成分（Ｂ）と前記芳香族ビニル系化合物とを混練した後、前記ポリスチレン成分（Ａ）と溶融混練することが好ましい。
〔６〕本発明に係るスチレン系樹脂組成物の製造方法おいて、前記芳香族ビニル系化合物は、スチレン単量体であり、
前記工程（Ｉ）は、前記ポリフェニレンエーテル原料成分（Ｂ１）とスチレン単量体との共存下で前記スチレン単量体を重合させてポリスチレン成分（Ａ）を生成し、当該ポリスチレン成分（Ａ）と、前記ポリフェニレンエーテル原料成分（Ｂ１）と、前記芳香族ビニル系化合物である前記スチレン単量体と、を含む配合物を６０℃以上２５０℃以下の温度範囲で加熱する工程であることが好ましい。 The present invention is as shown below.
[1] The present invention comprises 49.6 to 98.6% by mass of a polystyrene component (A) containing a styrene resin,
The following general formula (I):

(In general formula (I) above, R ¹ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms; R ² represents a phenyl group substituted with a substituent L or unsubstituted; —COO—R ⁶ (R ⁶ is an alkyl group having 1 to 8 carbon atoms) or a nitrile group, and R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom or 1 to 3 carbon atoms and the substituent L represents an alkyl group having 1 to 4 carbon atoms, and one or more hydrogen atoms in the alkyl group having 1 to 4 carbon atoms may be substituted with a halogen atom. However, R ³ and R ⁴ are not methyl groups at the same time.)
1 to 50% by mass of a polyphenylene ether component (B) containing a modified polyphenylene ether-based resin having a terminal group represented by
A styrenic resin composition containing 0.4% by mass or less of an oligomer component (C) containing a styrene oligomer.
[2] In the present invention, the terminal structure represented by the chemical formula (I) of the modified polyphenylene ether resin is 0.5 units or more with respect to 1000 units of the main chain structure of the entire polyphenylene ether component (B). It preferably contains 10 units or less.
[3] A method for producing a styrenic resin composition according to the present invention comprises a polystyrene component (A), a polyphenylene ether component (B) containing a modified polyphenylene ether resin having an imino group at its end, and an aromatic vinyl-based A step (I) of heating and melting a compound containing a compound in a temperature range of 60° C. or higher and 250° C. or lower to prepare a melt;
and a step (II) of devolatilizing the compound or the melt under temperature conditions of 200° C. or higher and 250° C. or lower.
[4] In the method for producing a styrenic resin composition according to the present invention, the aromatic vinyl compound may be added in an amount of 1 to 1000 parts by weight per 100 parts by weight of the polyphenylene ether component (B). preferable.
[5] In the method for producing a styrenic resin composition according to the present invention, the compound is obtained by kneading the polyphenylene ether component (B) and the aromatic vinyl compound in advance, and then kneading the polystyrene component (A). It is preferable to melt-knead with.
[6] In the method for producing a styrenic resin composition according to the present invention, the aromatic vinyl compound is a styrene monomer,
In the step (I), the styrene monomer is polymerized in the presence of the polyphenylene ether raw material component (B1) and the styrene monomer to produce a polystyrene component (A), and the polystyrene component (A) and , The step of heating a compound containing the polyphenylene ether raw material component (B1) and the styrene monomer, which is the aromatic vinyl compound, at a temperature range of 60°C or higher and 250°C or lower.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a styrenic resin composition having low odor, moldability and excellent appearance, and a method for producing the same.

FIG. 1 is a schematic diagram showing an example of a method for producing a styrene-based resin composition of the present embodiment. Show how to knead. FIG. 2 is a schematic diagram showing another example of the method for producing the styrene-based resin composition of the present embodiment, showing a method of heating, melting and kneading raw materials using a polymerization solvent. FIG. 3 is a schematic diagram showing another example of the method for producing a styrenic resin composition of the present embodiment. , indicating how to heat. FIG. 4 is a schematic diagram showing another example of the method for producing the styrene-based resin composition of the present embodiment, in which polymerization of the polystyrene-based resin and mixing with the polyphenylene ether raw material component (B1) are carried out in the same step. Show how.

（上記一般式（Ｉ）中、Ｒ^１は、水素原子、ハロゲン原子、又は炭素原子数１～４のアルキル基を表し、Ｒ^２は、置換基Ｌにより置換される又は無置換のフェニル基、－ＣＯＯ－Ｒ^６（Ｒ^６は、炭素原子数１～８のアルキル基である。）、又はニトリル基を表し、Ｒ^３、Ｒ^４及びＲ^５はそれぞれ独立して、水素原子又は炭素原子数１～３のアルキル基を表し、置換基Ｌは、炭素原子数１～４のアルキル基を表し、当該炭素原子数１～４のアルキル基中の１以上の水素原子はハロゲン原子に置換されてもよい。但し、Ｒ^３及びＲ^４が同時にメチル基となることはない。なお、上記一般式中（Ｉ）中の＊は他の原子との結合を表す。）で表される基を末端に有する改質ポリフェニレンエーテル系樹脂を含み、成分（Ｃ）はスチレンオリゴマーを含む。
これにより、低臭気性、成形性、及び外観に優れるスチレン系樹脂組成物を提供できる。 Embodiments of the present invention (hereinafter referred to as "present embodiments") will be described below, but the present invention is not limited to these embodiments.
"Styrene resin composition"
The styrene resin composition of the present embodiment comprises a polystyrene component (A) (hereinafter referred to as component (A)), a polyphenylene ether component (B) (hereinafter referred to as component (B)), and an oligomer component (C) (hereinafter referred to as Component (C)) and Then, component (A): 49.6 to 98.6% by mass, component (B): 1 to 50% by mass and component (C): It contains 0.4% by mass or less. Further, component (A) contains a styrenic resin, and component (B) has the following general formula (I):

(In general formula (I) above, R ¹ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms; R ² represents a phenyl group substituted with a substituent L or unsubstituted; —COO—R ⁶ (R ⁶ is an alkyl group having 1 to 8 carbon atoms) or a nitrile group, and R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom or a number of carbon atoms represents an alkyl group having 1 to 3, substituent L represents an alkyl group having 1 to 4 carbon atoms, and at least one hydrogen atom in the alkyl group having 1 to 4 carbon atoms is substituted with a halogen atom; However, R ³ and R ⁴ cannot be methyl groups at the same time.In addition, * in (I) in the general formula above represents a bond with another atom. and component (C) contains a styrene oligomer.
This makes it possible to provide a styrenic resin composition with low odor, moldability, and excellent appearance.

Each component (A) to (D) will be described below.
"Polystyrene component (A)"
The polystyrene component (A) that can be used in this embodiment is a component containing a styrene-based resin as a main component. The styrene-based resin is a resin obtained by polymerizing a styrene-based monomer and, if necessary, one or more selected from other vinyl monomers copolymerizable therewith and rubber-like polymers. The styrenic resin is not particularly limited, but is, for example, a rubber-modified styrenic resin in which particles of the rubber-like polymer (a) are dispersed in a styrenic resin matrix such as polystyrene, or a styrenic copolymer resin. is mentioned. Therefore, the styrenic resin according to the present invention contains a styrenic monomer as an essential component and, if necessary, other vinyl monomer units and/or rubber-like polymer monomer units.

In the present embodiment, the styrene-based resin that is the main component of the polystyrene component (A) is preferably polystyrene or a styrene-based copolymer resin.
In the present specification, "contains styrene resin as a main component" means that 90% by mass or more of styrene resin accounts for the total amount (100% by mass) of polystyrene component (A).
In the present embodiment, the content of the polystyrene component (A) with respect to the total amount (100% by mass) of the entire styrene resin composition is preferably 49.6 to 98.6% by mass, and 55 to 95% by mass. more preferably 60 to 90% by mass.

In the present embodiment, polystyrene is a homopolymer of styrene-based monomers, and commonly available materials can be appropriately selected and used. Styrenic monomers constituting polystyrene include, in addition to styrene, α-methylstyrene, α-methyl-p-methylstyrene, ο-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene, ethyl Styrene, isobutylstyrene, and styrene derivatives such as t-butylstyrene or bromostyrene and indene. Styrene is particularly preferred from an industrial point of view. These styrenic monomers can be used singly or in combination of two or more. Polystyrene is not excluded from further containing monomer units other than the above-mentioned styrene-based monomer units within a range that does not impair the effects of the present invention, but typically consists of styrene-based monomer units.
In the present embodiment, the weight average molecular weight (Mw) of polystyrene is preferably 100,000 to 350,000, more preferably 120,000 to 300,000, still more preferably 140,000 to 240,000. . When the weight-average molecular weight (Mw) is from 100,000 to 350,000, a resin having excellent balance between mechanical strength and fluidity can be obtained, and gel matter is less mixed. The weight average molecular weight (Mw) is a value obtained by standard polystyrene conversion using gel permeation chromatography.

-Rubber Modified Styrenic Resin-
In the present embodiment, the rubber-modified styrene-based resin is a styrene-based resin as a matrix in which particles of the rubber-like polymer (a) (also referred to as rubber-like polymer (a) particles) are dispersed. It can be produced by polymerizing a styrenic monomer in the presence of the rubber-like polymer (a).
The styrenic monomer constituting the rubber-modified styrenic resin of the present embodiment is the same as the styrenic monomer that can be used in the polystyrene described above. Styrene is particularly preferred. These styrenic monomers can be used singly or in combination of two or more.
The rubber-like polymer (a) particles contained in the rubber-modified styrenic resin of the present embodiment include, for example, a resin containing a styrenic monomer unit obtained from the above styrenic monomer inside. and/or may be grafted with a resin containing styrenic monomer units on the outside.
Examples of the rubber-like polymer (a) include polybutadiene (including forms encapsulating polystyrene or acrylic resin), polyisoprene, natural rubber, polychloroprene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer. etc. can be used, but polybutadiene or styrene-butadiene copolymer is preferred. Both high cis polybutadiene with a high cis content and low cis polybutadiene with a low cis content can be used for the polybutadiene. Both a random structure and a block structure can be used as the structure of the styrene-butadiene copolymer. One or more of these rubber-like polymers (a) can be used. Saturated rubber obtained by hydrogenating butadiene rubber can also be used.
Examples of such rubber-modified styrene resins include HIPS (high impact polystyrene), ABS resin (acrylonitrile-butadiene-styrene copolymer), AAS resin (acrylonitrile-acrylic rubber-styrene copolymer), AES resin ( acrylonitrile-ethylene propylene rubber-styrene copolymer) and the like.
When the rubber-modified styrene-based resin is a HIPS-based resin, among these rubber-like polymers (a), particularly preferred is a high-cis polybutadiene composed of 90 mol % or more of cis-1,4 bonds. In the high-cis polybutadiene, the vinyl 1,2 bond is preferably 6 mol % or less, particularly preferably 3 mol % or less.
The content of compounds having a cis 1,4, trans 1,4, or vinyl 1,2 structure as isomers related to the constituent units of the high-cis polybutadiene was measured using an infrared spectrophotometer and measured by the Morello method. It can be calculated by data processing by
The high-cis polybutadiene can be easily obtained by polymerizing 1,3-butadiene using a known production method, for example, a catalyst containing an organoaluminum compound and a cobalt or nickel compound.

The content of the rubber-like polymer (a) contained in the rubber-modified styrenic resin is preferably 3 to 20% by mass, more preferably 5 to 15% by mass, based on 100% by mass of the rubber-modified styrenic resin. is. If the content of the rubber-like polymer (a) is less than 3% by mass, the impact resistance of the styrene-based resin may deteriorate. Moreover, when the content of the rubber-like polymer (a) exceeds 20% by mass, the flame retardancy may be lowered.
In the present disclosure, the content of the rubber-like polymer (a) contained in the rubber-modified styrenic resin is a value calculated using pyrolysis gas chromatography.

The average particle size of the rubber-like polymer (a) particles contained in the rubber-modified styrenic resin is preferably 0.5 to 4.0 μm, more preferably 0.5 to 4.0 μm, from the viewpoint of impact resistance and flame retardancy. 0.8 to 3.5 μm.
In the present disclosure, the average particle size of the rubber-like polymer (a) particles contained in the rubber-modified styrenic resin can be measured by the following method.
A 75 nm-thick ultra-thin section is prepared from a rubber-modified styrenic resin stained with osmium tetroxide, and photographed at a magnification of 10,000 using an electron microscope. In the photograph, particles dyed black are rubber-like polymer (a) particles. From the picture, the following formula (N1):
Average particle size = ΣniDri ³ /ΣniDri ² (N1)
(In the above formula (N1), ni is the number of rubber-like polymer (a) particles having a particle diameter Dri, and the particle diameter Dri is a particle diameter calculated as a circle-equivalent diameter from the area of the particles in the photograph. ) to calculate the area-average particle size, which is defined as the average particle size of the rubber-like polymer (a) particles. For this measurement, a photograph is loaded into a scanner at a resolution of 200 dpi and measured using particle analysis software of an image analyzer IP-1000 (manufactured by Asahi Kasei Co., Ltd.).

The reduced viscosity of the rubber-modified styrenic resin (which is an index of the molecular weight of the rubber-modified styrenic resin) is preferably in the range of 0.50 to 0.85 dL/g, more preferably 0.55. ~0.80 dL/g. If it is less than 0.50 dL/g, the impact strength may decrease, and if it exceeds 0.85 dL/g, the fluidity may decrease, resulting in a decrease in moldability.
In the present disclosure, the reduced viscosity of the rubber-modified styrenic resin is a value measured in a toluene solution at 30° C. and a concentration of 0.5 g/dL.

The method for producing the rubber-modified styrenic resin is not particularly limited, but bulk polymerization (or solution polymerization) in which a styrenic monomer (and a solvent) is polymerized in the presence of the rubber-like polymer (a), Alternatively, it can be produced by bulk-suspension polymerization that shifts to suspension polymerization during the reaction, or emulsion graft polymerization that polymerizes a styrenic monomer in the presence of the rubber-like polymer (a) latex. In bulk polymerization, a mixed solution containing a rubber-like polymer (a), a styrenic monomer, and optionally an organic solvent, an organic peroxide, and/or a chain transfer agent is added to a complete mixing reactor. Alternatively, it can be produced by continuously supplying to a polymerization apparatus constructed by connecting a tank reactor and a plurality of tank reactors in series.

- Styrene-based copolymer resin -
In the present embodiment, the styrenic copolymer resin essentially contains a styrenic monomer unit and optionally contains an unsaturated carboxylic acid monomer unit and/or an unsaturated carboxylic acid ester monomer unit. It is a resin contained in Styrene-based copolymer resin, when the total content of styrene-based monomer units, unsaturated carboxylic acid-based monomer units, and unsaturated carboxylic acid ester-based monomer units is 100 mass%, styrene-based monomer The content of the monomer unit is preferably 69 to 98% by mass, more preferably 74 to 96% by mass, still more preferably 77 to 92% by mass.
In the styrenic copolymer resin, the unsaturated carboxylic acid-based monomer unit plays a role of improving heat resistance. When the total content of styrene-based monomer units, unsaturated carboxylic acid-based monomer units, and unsaturated carboxylic acid ester-based monomer units in the styrene-based copolymer resin is 100% by mass, unsaturated carboxylic acid The content of acid monomer units is preferably 0 to 16% by mass, more preferably 0 to 14% by mass, still more preferably 0 to 13% by mass.
In general, styrene-methacrylic acid-based resins including styrene-methacrylic acid-methyl methacrylate copolymer resins are produced by radical polymerization in most cases on an industrial scale. Various alcohols can be added to the polymerization system to suppress the polymerization reaction.

The unsaturated carboxylic acid ester-based monomer suppresses the dehydration reaction of the unsaturated carboxylic acid-based monomer through intermolecular interaction with the unsaturated carboxylic acid-based monomer, and the mechanical strength of the resin can be used to improve Furthermore, the unsaturated carboxylic acid ester monomer contributes to the improvement of resin properties such as weather resistance and surface hardness.

In the present embodiment, when the total content of styrene-based monomer units, unsaturated carboxylic acid-based monomer units, and unsaturated carboxylic acid ester-based monomer units is 100% by mass, unsaturated carboxylic acid ester The content of system monomer units is preferably 0 to 15% by mass, more preferably 1 to 12% by mass, still more preferably 2 to 10% by mass. By setting the content to 15% by mass or less, the fluidity of the resin can be improved and the water absorption can be suppressed. In addition, by setting the content of the unsaturated carboxylic acid ester-based monomer unit to 0% by mass, it is possible to improve heat resistance and reduce costs, but from the above viewpoint, the unsaturated carboxylic acid ester-based monomer The body unit content can also be greater than 0% by weight.
When an unsaturated carboxylic acid-based monomer and an unsaturated carboxylic acid ester-based monomer unit are bonded side by side, if a high-temperature, high-vacuum devolatilization apparatus is used, a dealcoholization reaction may occur depending on the conditions. Six-membered cyclic anhydrides may be formed. Although the copolymer resin of the present embodiment may contain this six-membered cyclic anhydride, it is preferable that the amount of the six-membered cyclic anhydride produced is as small as possible because it reduces fluidity.

In the present embodiment, styrene-based monomer units (e.g., styrene monomer units), unsaturated carboxylic acid-based monomer units (e.g., methacrylic acid monomer units) and unsaturated The content of saturated carboxylic acid ester-based monomeric units (for example, methyl methacrylate monomeric units) can be obtained from the integral ratio of the spectrum measured by a proton nuclear magnetic resonance ( ¹ H-NMR) spectrometer. can.

In the present embodiment, the styrene-based copolymer resin includes styrene-based monomer units and optional monomer units other than unsaturated carboxylic acid-based monomer units and unsaturated carboxylic acid ester-based monomer units. is not excluded as long as it does not impair the effects of the present invention. However, the styrenic copolymer resin in the present invention is typically composed of styrenic monomer units, unsaturated carboxylic acid monomer units, and unsaturated carboxylic acid ester monomer units. is preferred.

The styrene-based monomer constituting the styrene-based copolymer resin of the present embodiment is the same as the styrene-based monomer that can be used in the polystyrene described above.
The unsaturated carboxylic acid-based monomer constituting the styrene-based copolymer resin of the present embodiment is not particularly limited, but examples thereof include methacrylic acid, acrylic acid, maleic anhydride, maleic acid, fumaric acid, and itaconic acid. be done. As the unsaturated carboxylic acid-based monomer, methacrylic acid is preferable because it has a large effect of improving heat resistance and is liquid at room temperature and excellent in handleability. These unsaturated carboxylic acid-based monomers can be used singly or in combination of two or more.

The unsaturated carboxylic acid ester-based monomer constituting the copolymer resin of the present embodiment is not particularly limited, but examples thereof include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, ( butyl meth)acrylate, cyclohexyl (meth)acrylate, and the like. As the (meth)acrylic acid ester-based monomer, methyl (meth)acrylate is preferable because it has little effect on deterioration of heat resistance. These unsaturated carboxylic acid ester monomers can be used singly or in combination of two or more.
In the present embodiment, the weight average molecular weight (Mw) of the styrenic copolymer resin is preferably 100,000 to 350,000, more preferably 120,000 to 300,000, still more preferably 140,000 to 240. , 000. When the weight-average molecular weight (Mw) is from 100,000 to 350,000, a resin having excellent balance between mechanical strength and fluidity can be obtained, and gel matter is less mixed. The weight average molecular weight (Mw) is a value obtained by standard polystyrene conversion using gel permeation chromatography.
In the present embodiment, the method for polymerizing the copolymer resin is not particularly limited, but for example, a bulk polymerization method or a solution polymerization method can be suitably employed as a radical polymerization method. The polymerization method mainly includes a polymerization step of polymerizing raw materials for polymerization (monomer components) and a devolatilization step of removing volatile matter such as unreacted monomers and polymerization solvent from the polymerization product.

"Polyphenylene ether component (B)"
The styrenic resin composition according to this embodiment essentially contains a polyphenylene ether component (B). The polyphenylene ether component (B) in the present embodiment is a component containing a modified polyphenylene ether resin having a chemical structure represented by general formula (I). In other words, the polyphenylene ether component (B) is a polyphenylene ether-based resin (b1) and a polyphenylene ether-based resin (b2) that have different chemical structures from the modified polyphenylene ether-based resin and the modified polyphenylene ether-based resin. , contains The polyphenylene ether-based resin (b1) is a polyphenylene ether-based resin having a terminal hydroxyl group-unsealed structure and having an amino group or an imino group at its terminal. For example, the polyphenylene ether-based resin (b1) may have a repeating unit structure represented by the following general formula (II) and a terminal group represented by the following general formula (III), as described later.
Further, the polyphenylene ether-based resin (b2) is a polyphenylene ether-based resin other than the modified polyphenylene ether-based resin and the polyphenylene ether-based resin (b1), which has a repeating unit structure represented by the following general formula (II). Possible.

In the present embodiment, the content of the polyphenylene ether component (B) with respect to the total amount (100% by mass) of the entire styrene resin composition is preferably 1 to 50% by mass, and may be 5 to 45% by mass. More preferably, 10 to 40% by mass is even more preferable. In the present embodiment, for 1000 repeating structural units of the main chain of the polyphenylene ether component (B) (repeating units represented by the chemical formula (II) contained in the polyphenylene ether component (B)), the general formula (I) The terminal structure of preferably contains 0.5 to 10 units, more preferably 1 to 10 units, still more preferably 1 to 8 units, and particularly preferably 2 to 6 units.
When the terminal structure represented by general formula (I) exceeds 10 units with respect to 1000 repeating units represented by chemical formula (II), the polyphenylene ether component (B) contains a large amount of resin having a low molecular weight, Various physical properties tend to decrease. Further, when the terminal structure represented by the general formula (I) is less than 0.5 units per 1000 repeating units represented by the chemical formula (II), the odor peculiar to the polyphenylene ether component (B) is reduced at a high level. becomes difficult to reduce. The number of repeating units in the terminal structure of general formula (I) is calculated using ¹ H-NMR as described in Examples.

The weight average molecular weight (Mw) of the entire polyphenylene ether component (B) in the present embodiment is desirably 19,000 to 150,000, more preferably 30,000 to 110,000, and still more preferably 40,000 to 800,000. be. If the weight average molecular weight (Mw) is less than 19,000, the strength will be insufficient, and if it exceeds 150,000, the fluidity will be reduced.

-Modified polyphenylene ether resin-
As described in Patent Documents 1 and 2 described above, polyphenylene ether generally generates an odor during heat processing, and there is a current situation that improvement in workability during heat processing has been desired. Therefore, in the present embodiment, a modified polyphenylene ether resin in which the terminal hydroxyl groups are blocked is used for the purpose of suppressing the modification of the terminal hydroxyl groups, which is one of the causes of the odor of polyphenylene ether.

（上記一般式（Ｉ）中、Ｒ^１は、水素原子、ハロゲン原子、又は炭素原子数１～４のアルキル基を表し、Ｒ^２は、置換基Ｌにより置換される又は無置換のフェニル基、－ＣＯＯ－Ｒ^６（Ｒ^６は、炭素原子数１～８のアルキル基）、又はニトリル基を表し、Ｒ^３、Ｒ^４及びＲ^５はそれぞれ独立して、水素原子又は炭素原子数１～３のアルキル基を表し、置換基Ｌは、炭素原子数１～４のアルキル基を表し、当該炭素原子数１～４のアルキル基中の１以上の水素原子はハロゲン原子に置換されてもよい。但し、Ｒ^３及びＲ^４が同時にメチル基となることはない。）で表される基を１又は２以上の末端に有し、かつ後述の一般式（ＩＩ）で表される繰返し単位構造を有するポリフェニレンエーテル系重合体をいう。換言すると、当該改質ポリフェニレンエーテル系樹脂は、ポリフェニレンエーテル系樹脂（ｂ１）の１又は２以上の末端部を、上記一般式（Ｉ）で表される基に改質された重合体をいう。 The modified polyphenylene ether-based resin in this embodiment has the following general formula (I):

(In general formula (I) above, R ¹ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms; R ² represents a phenyl group substituted with a substituent L or unsubstituted; —COO—R ⁶ (R ⁶ is an alkyl group having 1 to 8 carbon atoms) or a nitrile group, and R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom or 1 to 3 carbon atoms and the substituent L represents an alkyl group having 1 to 4 carbon atoms, and one or more hydrogen atoms in the alkyl group having 1 to 4 carbon atoms may be substituted with a halogen atom. provided that R ³ and R ⁴ are not methyl groups at the same time. It refers to a polyphenylene ether-based polymer having In other words, the modified polyphenylene ether-based resin refers to a polymer in which one or more terminal portions of the polyphenylene ether-based resin (b1) are modified to groups represented by the general formula (I).

In general formula (I) above, R ¹ preferably represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. In general formula (I) above, R ² preferably represents a phenyl group substituted with a substituent L or unsubstituted. In general formula (I) above, the substituent L preferably represents an alkyl group having 1 to 4 carbon atoms.
In general formula (I) above, R ³ , R ⁴ and R ⁵ preferably each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

In the present specification, examples of alkyl groups having 1 to 8 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl and octyl groups. Examples of the alkyl group having 1 to 4 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group and tert-butyl group.
The modified polyphenylene ether according to this embodiment is obtained by modifying the polyphenylene ether-based resin (b1) with a capping compound (for example, an aromatic vinyl compound described later).

（上記一般式（ＩＩ）中、Ｒ^３、Ｒ^４、Ｒ^５、及びＲ^６はそれぞれ独立して、水素原子、ハロゲン原子、炭素原子数１～８のアルキル基、置換基Ｌにより置換される又は無置換のフェニル基、ハロアルキル基、アミノアルキル基、炭化水素オキシ基、又は少なくとも２個の炭素原子がハロゲン原子と酸素原子とを隔てているハロ炭化水素オキシ基からなる群から選択されるものである。）

（上記一般式（ＩＩＩ）中、Ｒ^３、Ｒ^４及びＲ^５はそれぞれ独立して、水素原子又は炭素原子数１～３のアルキル基を表し、Ｒ^ａ、Ｒ^ｂ、Ｒ^ｃ及びＲ^ｄはそれぞれ独立して、水素原子又は炭素原子数１～８のアルキル基を表し、これらＲ^ａ、Ｒ^ｂ、Ｒ^ｃ及びＲ^ｄは同時に水素原子であることはない。） The polyphenylene ether resin (b1) used in the present embodiment has a repeating unit structure represented by the following general formula (II) and a terminal group represented by the following general formula (III), and the terminal group The total number is preferably 0.8 or less per 100 phenylene ether units (= repeating unit structure represented by the following general formula (II)) constituting the polyphenylene ether resin (b1). , is preferably 0.01 or less.

(In general formula (II) above, R ³ , R ⁴ , R ⁵ and R ⁶ are each independently substituted by a hydrogen atom, a halogen atom, an alkyl group having 1 to 8 carbon atoms, or a substituent L or an unsubstituted phenyl group, a haloalkyl group, an aminoalkyl group, a hydrocarbonoxy group, or a halohydrocarbonoxy group in which at least two carbon atoms separate the halogen atom from the oxygen atom. is.)

(In general formula (III) above, R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R ^a , R ^b , R ^c and R ^d are Each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and these R ^a , R ^b , R ^c and R ^d are not hydrogen atoms at the same time.)

In general, when synthesizing a polyphenylene-based resin, a substituent is added to the terminal aromatic ring of the intermediate of the polyphenylene-based resin, and the added substituent is activated to cause a side reaction. Coloring (yellowing) may occur. In addition, when the polyphenylene resin or the intermediate is exposed to high temperature, Fries-type transition may occur to form a condensed ring such as a fluorenone ring, resulting in coloration. However, when a structure such as the terminal group represented by the above general formula (III), for example, a solvent or the like is added to the active site of the intermediate (for example, an amine or imine is added), it causes coloring. Although the side reaction can be suppressed, it causes odor during heat processing. Therefore, in polyphenylene-based resins, there may be a trade-off relationship between low odor and yellowness.
The ratio of the unit (general formula (III)) in which the amino group at the end of the polyphenylene ether is substituted is calculated by ¹ H-NMR or the like according to the method described later in Examples.

In general formula (II) above, R ³ , R ⁴ , R ⁵ and R ⁶ preferably each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
Preferred forms of the polyphenylene ether resin (b1) of the present embodiment include poly(2,6-dimethyl-1,4-phenylene ether), poly(2-methyl-6-ethyl-1,4-phenylene ether), One or more polymers selected from the group consisting of poly(2-methyl-6-phenyl-1,4-phenylene ether) and poly(2,6-dichloro-1,4-phenylene ether), It preferably has a terminal group represented by general formula (III), and the total number of the terminal groups is 0.8 or less per 100 phenylene ether units constituting the polymer.

The weight average molecular weight (Mw) of the polyphenylene ether resin (b1) in the present embodiment is preferably 20,000 to 120,000, more preferably 30,000 to 100,000, still more preferably 40,000 to 70, 000. If the weight average molecular weight (Mw) is 20,000 or less, the strength will be insufficient, and if it exceeds 120,000, the fluidity will be reduced.
The weight-average molecular weight (Mw) can be adjusted by appropriately selecting conditions such as the atmosphere, solvent type, catalyst type, reaction temperature, reaction time, etc., particularly the catalyst type, during oxidative coupling polymerization. In the present disclosure, the weight average molecular weight (Mw) can be measured by GPC as a polystyrene equivalent molecular weight.
The polyphenylene ether-based resin (b2) that can be contained in the polyphenylene ether component (B) in the present embodiment is not particularly limited, and is a homopolymer having a repeating unit structure represented by the general formula (II) and / Alternatively, a known resin can be used as long as it is a copolymer. Moreover, the polyphenylene ether-based resin (b2) may have the same chemical structure as the polyphenylene ether-based resin (b1) except that it has a terminal group represented by the general formula (II). The polyphenylene ether resin (b2) includes, for example, poly(2,6-dimethyl-1,4-phenylene ether), poly(2-methyl-6-ethyl-1,4-phenylene ether), poly(2- methyl-6-phenyl-1,4-phenylene ether) and poly(2,6-dichloro-1,4-phenylene ether).

The weight average molecular weight (Mw) of the polyphenylene ether resin (b2) in the present embodiment is desirably 20,000 to 120,000, more preferably 30,000 to 100,000, and still more preferably 40,000 to 70,000. When the weight-average molecular weight (Mw) is 20,000 or less, the strength is insufficient, and when the Z-average molecular weight (Mz) is more than 120,000, the fluidity is lowered.

<Method for producing polyphenylene ether component (B)>
In the present embodiment, the method for producing the polyphenylene ether component (B) (eg, polyphenylene ether resins (b1) and (b2)) is not particularly limited, and conventionally known methods can be used. For example, it can be easily produced by oxidative polymerization of, for example, 2,6-xylenol using the complex of cuprous salt and amine described in US Pat. No. 3,306,874 as a catalyst. Alternatively, US Pat. No. 3,306,875, US Pat. No. 3,257,357, US Pat. It can be produced by methods described in publications and the like.

In this embodiment, the polyphenylene ether component (B) is produced by oxidative coupling of phenolic compounds. The oxidation coupling reaction catalyst for the polyphenylene ether resin (B) is not particularly limited, but at least one of heavy metal compounds such as copper, manganese and cobalt is used (U.S. Pat. Nos. 4,042,056 and 4,042,056, 3,306,874 and 3,306,875).
Specific examples of the phenol compound include phenol, o-, m-, p-cresol, 2,6-, 2,5-, 2,4- or 3,5-dimethylphenol, 2-methyl-6-phenyl phenol, 2,6-diphenylphenol, 2,6-diethylphenol, 2-methyl-6-t-butylphenol and the like. Two or more of the above phenol compounds may be copolymerized, and two or more of the resulting homopolymers or copolymers may be used in combination. Among the above phenol compounds, 2,6-dimethylphenol is particularly suitable, and therefore, in the present embodiment, poly(2,6-dimethyl-1,4-phenylene) ether obtained by polymerizing this gives good results. give.

In the styrene-based resin composition of the present embodiment, the polystyrene component (A) and the polyphenylene ether component (B) can be separated by the following method and the molecular weight of each component can be measured. After dissolving the styrenic resin composition in chloroform to a concentration of 5% by mass, three times the amount of methanol is added for reprecipitation, followed by filtration and drying to recover the solid content. Next, the collected solid content is dissolved in dichloromethane at about 50° C. so that the solid content becomes 5% by mass, and then allowed to stand at −30° C. for 24 hours. After that, since the solid content is precipitated, the solid content is filtered and then dried to separate and recover the polyphenylene ether component (B). Then, three times the amount of methanol is added to the remaining dichloromethane solution to cause reprecipitation, and then the polystyrene component (A) is recovered by filtration and drying.

(Oligomer component (C))
The styrenic resin composition in this embodiment essentially contains an oligomer component (C). The oligomer component (C) in the styrene-based resin composition of the present embodiment is contained in an amount of 0.4% by mass or less with respect to the total amount (100% by mass) of the styrene-based resin composition. The oligomer component (C) in the present embodiment is contained as an impurity in the polystyrene component (A) (more specifically, a styrene resin), has two or more styrene monomer units, and has a weight average molecular weight of A styrene oligomer having a (Mw) of 10,000 or less, in particular dimers and trimers of styrene-based monomers produced during polymerization of the styrene-based resin that is the main component of the polystyrene component (A). ). Therefore, oligomeric component (C) can be a styrene oligomer.
In the present embodiment, the total amount of styrene oligomers (e.g., dimers and trimers of styrene monomers) is a predetermined amount (e.g., 0.4% by mass) or more, the oxides of dimers and trimers cause yellowing or odor. In addition, when the present resin composition is molded into a molded article, it gasifies and becomes a deposit on the molding machine, and as a result, it adheres to the molded article and becomes a contaminant, which is undesirable in terms of appearance.

The styrene oligomer in the present embodiment is 0.4% by mass or less, preferably 0.38% by mass or less, more preferably 0.36% by mass or less, relative to the entire styrene resin composition (100% by mass). is.
In addition, the chemical structure of styrene oligomers (eg, styrene dimer and trimer) depends on the styrene-based monomer contained in the styrene-based resin used, as described below.
The total amount of styrene oligomers (eg, styrene dimer and trimer) in the styrene resin composition of the present embodiment is measured using gas chromatography. Specifically, the following measurement conditions are used.
Apparatus: Agilent 6850 series GC system
Sample: After dissolving 1 g of the resin composition in 10 ml of MEK, 3 ml of methanol was added to precipitate the polymer, and the concentration of the components in the solution was measured.
Column: Agilent 19091Z-413E
Inlet temperature: 250°C
Detector temperature: 280°C
As a method for reducing the amount of dimers and trimers in the styrene resin composition to a predetermined value or less, there is a means of purifying the styrene resin or polystyrene component (A) by distillation.

The styrenic resin composition in the present embodiment may contain additives other than the above components (A) to (C) as long as they do not impair the effects of the present invention. The additive is not particularly limited, and examples thereof include inorganic compounds such as silica, calcium silicate, wollastonite, kaolin, clay, mica, zinc oxide, titanium oxide, and calcium carbonate; sodium stearate, stearic acid; Plasticizers such as magnesium, barium stearate, liquid paraffin, olefin waxes, and stearylamide compounds; phenolic antioxidants, phosphorus, nitrogen, or sulfur stabilizers; Known flame retardants, antistatic agents, coloring agents such as pigments, and the like can be used. The additive may be used singly or in combination of two or more.

The styrenic resin composition of the present embodiment may consist essentially of components (A) to (C) and optional additives. Moreover, it may be composed only of components (A) to (C).
"Consisting essentially of components (A) to (C) and optional additives" means that 95 to 100% by mass (preferably 98 to 100% by mass) of the styrenic resin composition is component (A) (C), or components (A) to (C) and optional additives.

"Method for producing styrenic resin composition"
The method for producing a styrenic resin composition in the present embodiment includes a polystyrene component (A), a polyphenylene ether raw material component (B1) containing a polyphenylene ether resin (b1) having an amino group or an imino group at the end, and an aromatic vinyl A step (I) of heating and melting a compound containing a compound containing a system compound in a temperature range of 60 ° C. or higher and 250 ° C. or lower, preferably in a temperature range of 60 ° C. or higher and 230 ° C. or lower, and the compound or obtained in the step (I) and a step (II) of devolatilizing the mixture at 200°C to 250°C.

In the production method of the present embodiment, the polystyrene component (A) and the polyphenylene ether raw material component (B) are heated (or heated and melted) at a relatively low temperature of 60 to 250 ° C., so that styrene oligomer and Fries type transition The yellowness index (YI) can be suppressed by suppressing the formation of condensed rings such as fluorenone rings. For example, as in Comparative Example 3 described later, it can be confirmed that when heated and melted at 290° C., a styrene oligomer is formed and the impact strength is not improved. Furthermore, it is thought that the high melting temperature facilitates the progress of the reaction, making it impossible to suppress the formation of a condensed ring such as a fluorenone ring, and thus to prevent yellowing.
In addition, in the present embodiment, the compound before heating or after heating is devolatilized, so the odor peculiar to polyphenylene ether can also be reduced.

Each step will be described below.
(Step (I))
The step (I) in the present embodiment includes a polystyrene component (A), a polyphenylene ether raw material component (B1) containing a polyphenylene ether resin (b1) having an amino group or an imino group at the end, and an aromatic vinyl compound. This is a step of heating and melting the compound in a temperature range of 60°C to 250°C.
In the above step (I), the compound containing the polystyrene component (A), the polyphenylene ether raw material component (B) and the aromatic vinyl compound is heated to a temperature range of 60° C. or higher and 250° C. or lower, preferably 60° C. or higher and 230° C. or lower. It suffices if it is heated and melted at Therefore, for example, the aromatic vinyl compound may coexist with the polystyrene component (A) and the polyphenylene ether raw material component (B1) from the beginning, or the aromatic vinyl compound may be mixed with the polyphenylene ether raw material component (B1). The polystyrene component (A) may be mixed later, or the aromatic vinyl compound may be added later to the polyphenylene ether starting material component (B1).
Alternatively, for example, an aromatic vinyl-based compound (styrene-based monomer) is used as a precursor of the polystyrene component (A), and the aromatic vinyl-based compound (e.g., styrene-based monomer) is polymerized. The resulting polymer may be used as the polystyrene component (A). That is, in the step (I) of the present embodiment, the polyphenylene ether raw material component (B1) and a styrene monomer that is an aromatic vinyl compound are mixed, and the styrene is polymerized under a temperature condition of, for example, 120 to 170 ° C. to obtain polystyrene. By generating the component (A), polymerization of the polystyrene component (A), kneading with the polyphenylene ether raw material component (B1), and polyphenylene ether resin (b1) having an amino group or an imino group at the end and an aromatic vinyl It is also possible to efficiently perform the three reactions with the system compound in the same step. At this time, a polymerization solvent may be used.
The polyphenylene ether raw material component (B1) refers to the raw material of the polyphenylene ether component (B), and contains the polyphenylene ether resin (b1) and the polyphenylene ether resin (b2). The polyphenylene ether-based resin (b1) and the polyphenylene ether-based resin (b2) are as defined above.

The polystyrene component (A) used in step (I) of the present embodiment is a component containing a styrene-based resin as a main component, and the same material as the above polystyrene component (A) can be used. In addition, the content of the polystyrene component (A) is preferably 49.6 to 98.6% by mass, more preferably 55 to 95% by mass, relative to the total amount (100% by mass) of the compound. more preferred. Also, the content of the styrene-based resin with respect to the total amount (100% by mass) of the polystyrene component (A) is preferably 90% by mass, more preferably 95 to 100% by mass.

The polyphenylene ether raw material component (B1) used in the step (I) of the present embodiment is a component containing a polyphenylene ether resin (b1) having an amino group or an imino group at the end, and the polyphenylene ether resin (b1) and a polyphenylene ether-based resin (b2) other than the polyphenylene ether-based resin (b1).
As the polyphenylene ether-based resin (b1) and the polyphenylene ether-based resin (b2), the same materials as the polyphenylene ether-based resin (b1) and the polyphenylene ether-based resin (b2) can be used.
The polyphenylene ether-based resin (b1) in the polyphenylene ether raw material component (B1) reacts with the aromatic vinyl compound to form a modified polyphenylene ether-based resin having a group represented by the general formula (I) at its end. Since a resin is formed, the polyphenylene ether raw material component (B1) is a precursor of the polyphenylene ether component (B).

Examples of the aromatic vinyl-based compound used in step (I) of the present embodiment include the same materials as the styrene-based monomers. Among them, styrene, α-methylstyrene, α-methyl-p-methylstyrene , o-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene, ethylstyrene, isobutylstyrene and t-butylstyrene are preferred. The aromatic vinyl compound is preferably added in an amount of 1 to 1000 parts by weight, more preferably 3 to 500 parts by weight, per 100 parts by weight of the polyphenylene ether raw material component (B1). Also, the aromatic vinyl compound of the present embodiment may be used as a polymerization solvent.

The formulation in the production method of the present embodiment may contain a polymerization solvent if necessary. Examples of the polymerization solvent include aromatic vinyl compounds, aromatic hydrocarbons such as ethylbenzene, dialkyl ketones such as methyl ethyl ketone, and the like. may be used.
In addition, in the production method of the present embodiment, the above additives may be added to the formulations and formulations (including melts and mixtures) within a range that does not impair the effects of the present invention.

In the present embodiment, the heating temperature is preferably at least the temperature at which the polystyrene component and the polyphenylene ether component (C) used are melted and at a temperature that suppresses thermal deterioration of each component. Specifically, the temperature range is 250° C. or lower, preferably 210° C. or higher and 250° C. or lower, and more preferably 220° C. or higher and 240° C. or lower. The temperature range referred to herein refers to the temperature range of the formulation. The heating time is not particularly limited, and can be appropriately adjusted depending on the extrusion rate per unit time or the type of extruder used for melt-kneading.
In the present embodiment, the blend is preferably obtained by previously mixing the polyphenylene ether raw material component (B1) and the aromatic vinyl compound, and then further mixing with the polystyrene component (A).
That is, by premixing a polyphenylene ether resin (b1) having an amino group or an imino group at the end with an aromatic vinyl compound, a modified polyphenylene ether having a terminal group represented by the general formula (I) It becomes easy to form a system resin.
In the present embodiment, the blend comprises the polystyrene component (A) containing a styrene-based resin obtained by polymerizing the styrene monomer in the presence of the polyphenylene ether component (B) and the styrene monomer, and the polyphenylene It preferably contains the ether component (B) and the unpolymerized styrene monomer.

(Step (II))
Step (II) of the present embodiment is a step of devolatilizing the compound or the mixture obtained in step (I) under predetermined conditions. Therefore, step (II) can be carried out either during step (I) or after step (I).
The devolatilization in the present embodiment refers to a process of removing volatile matter such as unreacted monomers and by-products, polymerization solvent, etc. at a predetermined temperature and under vacuum. As the devolatilization means, usual devolatilizers such as flash drums, twin-screw devolatilizers, thin film evaporators, extruders and the like can be used, but devolatilizers with a small stagnant portion are preferred. The temperature of the devolatilization treatment is preferably 190 to 250°C, more preferably 200 to 240°C, still more preferably 210 to 235°C. The degree of absolute vacuum (pressure) in the devolatilization treatment is preferably 0.13 to 4 kPa, more preferably 0.13 to 3 kPa, still more preferably 0.13 to 2.0 kPa. As the devolatilization method, for example, a method of reducing the pressure under heating to remove the volatile matter, and a method of removing the volatile matter through an extruder or the like designed for the purpose of removing the volatile matter are preferred.

An example of a preferred method for producing a styrenic resin composition according to the present embodiment will be described below with reference to FIGS.
The embodiment shown in FIG. 1 is a method in which solid polystyrene component (A) and polyphenylene ether raw material component (B1) are used as raw materials and melted by heating and kneaded. That is, a polystyrene resin 1 as a polystyrene component (A), a polyphenylene ether resin (b1) 2 as a polyphenylene ether raw material component (B1), an aromatic vinyl compound added as necessary, and a desired additive as necessary and are put into the extruder 5 from the raw material supply hopper, the mixture as the raw material is heated and melted at a temperature range of 210 ° C. or higher and 250 ° C. or lower, and the melt is transferred to the die side while kneading. . At that time, if necessary, after adding and mixing the aromatic vinyl compound to the melt, it is heated in a temperature range of 210 ° C. or higher and 250 ° C. or lower, and is heated to a predetermined temperature (for example, 200 to 250 ° C.) and under vacuum. (10.0 kPa or less) to perform devolatilization.
The raw material polystyrene resin 1 and/or polyphenylene ether resin (b1) 2 may be pelletized or granulated, mixed well in advance, and charged from one raw material supply hopper, or, for example, in multiple lots. When using , it may be charged from a plurality of raw material supply hoppers whose supply amount is adjusted for each lot and mixed in the extruder 5 .

The embodiment shown in FIG. 2 is a method of performing heat melting and kneading using a polymerization solvent. That is, as raw materials, a polystyrene resin 1 as a polystyrene component (A), a powdery polyphenylene ether resin (b1) 4 as a polyphenylene ether raw material component (B1), a polymerization solvent 3, and an aromatic compound added as necessary A vinyl-based compound and desired additives are weighed and fed into the extruder 5 from a raw material supply hopper, and the mixture as a raw material is heated and melted at a temperature range of 210 ° C. or higher and 250 ° C. or lower, and kneaded. Transfer the melt to the die side. At that time, if necessary, an aromatic vinyl compound is added to the melt and mixed, then heated in a temperature range of 210 ° C. or higher and 250 ° C. or lower, and a predetermined temperature (for example, 200 to 250 ° C.) and under vacuum ( 10.0 kPa or less).
In the embodiment shown in FIG. 2, since the powdery polyphenylene ether resin (b1) 4 is used, the amount of polymerization solvent 3 that improves the fluidity of the polyphenylene ether resin (b1) 4 is used to half After being solidified, it is brought into contact with the polystyrene-based resin 1 .

The embodiment shown in FIG. 3 is a method in which the raw materials are brought into a solution state by using a larger amount of polymerization solvent than in the embodiment of FIG. 2, and then heated. That is, as raw materials, a polystyrene resin 1 as a polystyrene component (A), a polyphenylene ether resin (b1) 4 as a polyphenylene ether raw material component (B1), a polymerization solvent 3, and an aromatic vinyl compound added as necessary , and desired additives are weighed and put into the dissolving tank 6 from the raw material supply hopper, and the compound as the raw material is heated in the temperature range of 210° C. or higher and 250° C. or lower. At that time, if necessary, after adding and mixing the aromatic vinyl compound to the formulation, the mixture may be heated in the temperature range of 210° C. or more and 250° C. or less. After that, devolatilization is performed at a predetermined temperature (eg, 200 to 250° C.) and under vacuum (10.0 kPa or less) by the devolatilization device 7 .

The embodiment shown in FIG. 4 is a method in which the polymerization of the polystyrene resin and the mixing with the polyphenylene ether raw material component (B1) are carried out in the same step. That is, as raw materials, a styrene-based monomer 9 which is a precursor of the polystyrene component (A), a polyphenylene ether-based resin (b1) 4 as a polyphenylene ether raw material component (B1), a polymerization solvent 3, and desired additives , If necessary, the polystyrene resin 1 is weighed, put into the dissolution tank 6 from the raw material supply hopper, and the mixture in the dissolution tank 6 is stirred and maintained at a temperature range of 120 ° C. or higher and 180 ° C. or lower. Then, the polyphenylene ether resin (b1) 4 is dissolved in the polymerization solvent 3 and the styrene monomer 9 to prepare a solution. Then, the solution is transferred to the reaction tank 8 and the styrene monomer 9 is polymerized to synthesize the styrene component (A). At this time, if necessary, an aromatic vinyl compound is further added to the melt and mixed, then heated in the temperature range of 210 ° C. or higher and 250 ° C. or lower, and the devolatilization device 7 sets the ) and under vacuum (10.0 kPa or less).

In the method for producing a styrenic resin composition of the present embodiment, the method of blending, melting, kneading, heating, and granulating raw materials is not particularly limited, and a method commonly used in the production of general styrenic resin compositions. can be used. For example, each of the above components blended (mixed) with a drum tumbler, Henschel mixer, etc. is heated, melted, and kneaded using a Banbury mixer, a single screw extruder, a twin screw extruder, a kneader, etc., and then a rotary cutter, a fan cutter, etc. A styrenic resin composition can be obtained by granulating. In order to achieve the target resin temperature, it is preferable to set the cylinder temperature of the extruder or the like to a temperature 10 to 20° C. lower than the resin temperature.

The molded article of this embodiment can be obtained by molding the styrene-based resin composition according to the present invention. The molded article of the present embodiment is not particularly limited as long as it is obtained by molding the resin composition of the embodiment according to the present invention.
In the present embodiment, the manufacturing method for obtaining the molded article from the styrene-based resin composition is not particularly limited, and it can be manufactured by a known molding method such as extrusion molding or injection molding. Specifically, extrusion molding includes, for example, extrusion molding, calendar molding, blow molding, extrusion foam molding, profile extrusion molding, laminate molding, inflation molding, T-die film molding, sheet molding, vacuum molding, pressure molding, direct blow molding and the like. Examples of injection molding include injection molding, RIM molding, injection foam molding, injection blow molding, and injection stretch blow molding.

EXAMPLES The embodiments of the present invention will be described in more detail below based on Examples and Comparative Examples, but the present invention is not limited to these Examples.
1. Measurement and Evaluation Methods The physical properties of the styrenic resin compositions obtained in Examples and Comparative Examples were measured and evaluated according to the following methods.

(1) Terminal group amount and hydroxyl terminal amount represented by general formula (I) and general formula (III) Samples of the polyphenylene ether component of the raw material and the styrenic resin composition obtained in each example and comparative example were , measured by ¹ H-NMR of a solution dissolved in deuterated chloroform (containing TMS), and from the peak area ratio, the amount of terminal groups represented by general formulas (I) and general formula (III) in the sample and The amount of terminal hydroxyl groups was quantified.

(2) Evaluation of amount of oligomer component (C) (dimer of styrene monomer and trimer of styrene monomer) When the total amount of the styrene resin compositions prepared in Examples and Comparative Examples is 100 parts by mass of the oligomer component (C) (dimer of styrene-based monomer and trimer of styrene-based monomer) was measured by gas chromatography.
-Sample preparation: After dissolving 2.0 g of resin in 20 mL of chloroform, 5 mL of methanol containing a standard substance (triphenylmethane) was added to reprecipitate the polymer component, and the supernatant was collected as a measurement solution.
・Measurement conditions Equipment: Agilent 6850 series GC system Detector: FID
Column: HP-1 (100% dimethylpolysiloxane) 30 m, film thickness 0.25 μm, 0.32 mmφ
Injection volume: 1 μL (splitless)
Column temperature: Hold at 40°C for 2 minutes → Heat up to 320°C at 20°C/min → Hold at 320°C for 15 minutes Inlet temperature: 250°C
Detector temperature: 280°C
Carrier gas: Helium

(3) Moldability The styrenic resin compositions obtained in Examples and Comparative Examples were molded using a sheet molding machine consisting of a vented 30 mm short-screw extruder and a hanger die, and the cylinder temperature and die temperature were set to 260°C. Extrusion was performed. Moldability was evaluated according to the following criteria.
◎: No dirt on the sheet, no black spot foreign matter ○: Little dirt on the sheet, no black spot foreign matter ×: Stain on the sheet, black spot foreign matter

(5) Color tone (Y.I.)
Using injection molded test pieces with a thickness of 2.0 mm obtained from the resin compositions obtained in the following examples and comparative examples, Nippon Denshoku Co., Ltd. color difference turbidity measurement in accordance with JIS K 7373 The yellow index of the styrenic resin composition was measured with a COH300A (trade name) instrument. Considering the purpose of toning, 40 or less was accepted.

(6) Odor The raw material polyphenylene ether component and the styrenic resin composition samples obtained in Examples and Comparative Examples were placed in a sample bottle, capped, and heated at 80° C. for 30 minutes. After that, the odor was smelled when the lid was opened, and the odor was evaluated by 10 evaluators using the following five-grade criteria from 1 to 5. The result of the odor evaluation was the arithmetic mean value of the odor evaluation results by 10 evaluators.
1: Odorless 2: Faint odor 3: Clear odor 4: Strong odor 5: Strong odor

2. Raw Materials Used in Examples and Comparative Examples (a-1) As the polystyrene component (A), a styrene resin (a-1) (polystyrene GX156 manufactured by PS Japan) was used.
(b-1) Polyphenylene ether-based resin (b-1) (Asahi Kasei polyphenylene ether S202A) was used as the polyphenylene ether raw material component (B1).
The amount of terminal groups represented by general formula (III) in the polyphenylene ether-based resin (b-1) is a phenylene ether unit constituting the polyphenylene ether-based resin (b-1) (represented by general formula (II) Repeating unit structure) was 0.8 units or less per 100 units.
(c-1) Aromatic vinyl compound: A styrene monomer was used.

3. Examples 1-6 and Comparative Examples 1-3
(Example 1)
Polyphenylene ether resin (b-1) powder is charged to the front stage of a tandem extruder equipped with a devolatilization device, and 9 styrene monomers are added to 100% by mass of the polyphenylene ether resin (b-1). 0% by mass, and kneading was carried out at a barrel temperature of 100°C. Then, using a side feeder, the styrene resin (a-1) was added, heated to 210° C., thoroughly mixed, and passed through a subsequent devolatilizing extruder equipped with a multi-stage vent at a barrel temperature of 230° C. , and devolatilized at a degree of vacuum of 100 kPa to 2 kPa to obtain the desired styrene-based resin composition (1). The styrene-based resin composition (1) obtained in Example 1 was evaluated for moldability, color tone, odor, and the like. Table 1 shows the composition ratio of the styrene-based resin composition (1) together with the evaluation results.

(Example 2)
The composition in Table 1 was prepared in the same manner as in Example 1 except that the amount of styrene monomer added as an aromatic vinyl compound was 12.0% by mass with respect to the polyphenylene ether resin (b-1) powder. A styrene-based resin composition (2) for the purpose of showing was obtained. After that, the same evaluation as in Example 1 was performed. Table 1 shows the composition ratio of the styrene-based resin composition (2) together with the evaluation results.

(Example 3)
In the same manner as in Example 1, except that the amount of the styrene monomer added as the aromatic vinyl compound was 4.0% by mass with respect to the polyphenylene ether resin (b-1). , the intended styrene-based resin composition (3) having the composition shown in Table 1 was obtained. After that, the same evaluation as in Example 1 was performed. Table 1 shows the composition ratio of the styrene-based resin composition (3) together with the evaluation results.

(Example 4)
An aromatic 45 parts by mass of a styrene monomer as a vinyl compound and 5 parts by mass of ethylbenzene as a solvent were added and mixed and dissolved at 80°C. The temperature of the dissolution tank was increased stepwise from 110°C to 170°C, and styrene was polymerized for 20 hours. After that, 15 parts by mass of ethylbenzene was further added, and the solvent was devolatilized at a vacuum degree of 100 to 2 kPa (abs) using a devolatilizing extruder equipped with a multi-stage vent heated to a barrel temperature of 230 ° C., and the composition shown in Table 1. A styrene-based resin composition (4) for the purpose of exhibiting was obtained. After that, the same evaluation as in Example 1 was performed. Table 1 shows the composition ratio of the styrene-based resin composition (4) together with the evaluation results.

(Example 5)
45 parts by mass of polyphenylene ether resin (b-1) powder was added with 45 parts by mass of styrene monomer as an aromatic vinyl compound and 10 parts by mass of ethylbenzene in a dissolution tank, and mixed and dissolved at 80°C. Subsequent operations were carried out in the same manner as in Example 4 to obtain the intended styrene-based resin composition (5) having the composition shown in Table 1. After that, the same evaluation as in Example 1 was performed. Table 1 shows the composition ratio of the styrene-based resin composition (5) together with the evaluation results.

(Example 6)
The composition in Table 1 was prepared in the same manner as in Example 1, except that the amount of the styrene monomer added as the aromatic vinyl compound was 1.0% by mass with respect to the polyphenylene ether resin (b-1) powder. A styrenic resin composition (6) for the purpose shown was obtained. After that, the same evaluation as in Example 1 was performed. Table 1 shows the composition ratio of the styrene-based resin composition (6) together with the evaluation results.

(Comparative example 1)
A styrenic resin composition (6) was obtained using the composition shown in Table 1 in the same manner as in Example 1, except that ethylbenzene was used instead of the styrene monomer in Example 1. After that, the same evaluation as in Example 1 was performed. Table 1 shows the composition ratio of the styrene-based resin composition (6) together with the evaluation results.

(Comparative example 2)
Using a twin-screw extruder, the styrene resin (a-1) and the polyphenylene ether resin (b-1) are each charged from a hopper and melt-kneaded at a temperature of 290 ° C. to obtain the composition shown in Table 1. A styrene resin composition (7) was obtained. After that, the same evaluation as in Example 1 was performed. Table 1 shows the composition ratio of the styrenic resin composition (7) together with the evaluation results.

(Comparative Example 3)
A styrene resin composition (8) was obtained in the same manner as in Example 1, except that the kneading temperature after adding the styrene resin (a-1) was 290°C. After that, the same evaluation as in Example 1 was performed. Table 1 shows the composition ratio of the styrene-based resin composition (8) together with the evaluation results.

1 Polystyrene resin (pellet)
2 Polyphenylene ether resin (b1) (pellet)
3 polymerization solvent 4 polyphenylene ether resin (b1) (powder)
5 Extruder equipped with devolatilizing device 6 Dissolving tank 7 Devolatilizing device 8 Reaction tank 9 Styrenic monomer

Claims (6)

49.6 to 98.6% by mass of a polystyrene component (A) containing a styrene resin,
The following general formula (I):

(In general formula (I) above, R ¹ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms; R ² represents a phenyl group substituted with a substituent L or unsubstituted; —COO—R ⁶ (R ⁶ is an alkyl group having 1 to 8 carbon atoms) or a nitrile group, and R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom or 1 to 3 carbon atoms and the substituent L represents an alkyl group having 1 to 4 carbon atoms, and one or more hydrogen atoms in the alkyl group having 1 to 4 carbon atoms may be substituted with a halogen atom. However, R ³ and R ⁴ are not methyl groups at the same time.
A styrenic resin composition containing 0.4% by mass or less of an oligomer component (C) containing a styrene oligomer. The styrenic resin according to claim 1, wherein the terminal structure represented by the chemical formula (I) includes 0.5 units or more and 10 units or less with respect to 1000 units of the main chain structure of the entire polyphenylene ether component (B). Composition. A compound containing a polystyrene component (A), a polyphenylene ether raw material component (B1) containing a polyphenylene ether resin (b1) having an amino group or an imino group at its end, and an aromatic vinyl compound is heated at 60°C or higher to 250°C. A step (I) of heating in a temperature range of ° C. or less;
A method for producing a styrenic resin composition, comprising a step (II) of devolatilizing the compound or the mixture obtained in the step (I) under a temperature condition of 200°C or higher and 250°C or lower. Production of the styrenic resin composition according to claim 3, wherein the aromatic vinyl compound is added in an amount of 1 to 1000 parts by weight per 100 parts by weight of the polyphenylene ether raw material component (B1). Method. 5. The styrene-based compound according to claim 3 or 4, wherein the blend is obtained by mixing the polyphenylene ether raw material component (B1) and the aromatic vinyl compound in advance and then mixing with the polystyrene component (A). A method for producing a resin composition. The aromatic vinyl compound is a styrene monomer,
In the step (I), the styrene monomer is polymerized in the presence of the polyphenylene ether raw material component (B1) and the styrene monomer to produce a polystyrene component (A), and the polystyrene component (A) and 3. A step of heating a compound containing the polyphenylene ether raw material component (B1) and the styrene monomer that is the aromatic vinyl compound at a temperature range of 60 ° C. or higher and 250 ° C. or lower. 6. A method for producing a styrenic resin composition according to any one of items 1 to 5.

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