JP2019006976A - Graft copolymer, thermoplastic resin composition, and molded article - Google Patents

Abstract

To provide a graft copolymer capable of effectively enhancing surface appearance, impact resistance, fluidity by blending the same to a thermoplastic resin containing polystyrene and/or polyphenylene ether, and a thermoplastic resin composition by blending the graft copolymer and a molded article thereof.SOLUTION: There is provided a graft copolymer (B) by graft copolymerizing an aromatic vinyl monomer in the presence of an olefin rubbery polymer (A) with average particle diameter of 0.1 to 1.0 μm, and having 5% weight reduction temperature of 300°C or higher. There are provided a thermoplastic resin composition containing the graft copolymer (B), and a thermoplastic resin containing polystyrene and/or polyphenylene ether, and a molded article thereof.SELECTED DRAWING: None

Description

  The present invention includes a graft copolymer that can effectively improve surface appearance and fluidity by blending with a thermoplastic resin containing polystyrene and / or polyphenylene ether, and the graft copolymer and polystyrene and / or Alternatively, the present invention relates to a thermoplastic resin composition containing a thermoplastic resin containing polyphenylene ether. The present invention also relates to a molded article formed by molding this thermoplastic resin composition.

Polystyrene has an excellent surface appearance, high tensile strength and rigidity, and is widely used in the fields of food containers, stationery, miscellaneous goods and the like. However, polystyrene has the disadvantage of low impact resistance.
Polyphenylene ether is a resin having excellent properties such as heat resistance, chemical resistance, mechanical properties, and electrical properties, but has disadvantages such as low moldability and impact resistance.

  Conventionally, in order to improve the impact resistance of polystyrene, a method of adding an impact resistance improving material obtained by graft copolymerization of a vinyl monomer to a rubber component is known.

For example, in Patent Document 1, in order to improve the impact resistance of polystyrene, an impact-resistant reinforcing material obtained by graft copolymerizing an aromatic vinyl monomer and a vinyl cyanide monomer with a rubbery polymer such as polybutadiene. Is added to the polystyrene.
However, the impact-resistant polystyrene of Patent Document 1 has a drawback that the surface appearance of the molded product is inferior. Further, Patent Document 1 has no description regarding fluidity, and there is a concern about deterioration of moldability due to a decrease in fluidity.

In addition, for improving the impact resistance of polyphenylene ether, a method of blending impact resistant polystyrene (high impact polystyrene, hereinafter referred to as HIPS) has been conventionally known.
However, HIPS is polymerized by dissolving butadiene in the styrene component, but has a drawback that the rubber content is low due to the low solubility of butadiene in styrene. For this reason, in order to express sufficient impact resistance, it is necessary to mix | blend a large amount of HIPS with respect to polyphenylene ether. Moreover, since HIPS contains butadiene in the rubber component, there is a concern that the heat resistance and flame retardancy, which are characteristics of polyphenylene ether, may be impaired, and it is difficult to achieve both impact resistance, flame retardancy, and heat resistance.
That is, in order to improve the impact resistance of polyphenylene ether, a large amount of HIPS must be blended. On the other hand, as a result of blending a large amount of HIPS, the inherent flame retardancy of polyphenylene ether is reduced. Therefore, in order to improve the flame retardancy, it is necessary to add a large amount of a flame retardant such as a phosphorus compound or a halogen compound.
For this reason, it is difficult to achieve both impact resistance and flame retardancy, and also results in a decrease in heat resistance, and there is a concern that the characteristics of polyphenylene ether will be lost and usable applications and fields will be limited. was there.

  In order to eliminate these drawbacks, Patent Document 2 employs a technique of blending a hydrogenated styrene / butadiene block copolymer in combination with HIPS, but in order to develop sufficient impact resistance. Not reached.

In Patent Document 3, in order to improve the impact resistance of polyphenylene ether, a graft copolymer obtained by graft-polymerizing aromatic vinyl to an ethylene-propylene-nonconjugated diene copolymer rubber latex is blended with polyphenylene ether. ing.
However, the graft copolymer of Patent Document 3 cannot achieve sufficient improvement in impact resistance.

JP 2004-256744 A JP-A-6-57127 Japanese Patent Laid-Open No. 4-68065

  In the present invention, by blending with a thermoplastic resin containing polystyrene and / or polyphenylene ether, the fluidity, the surface appearance of the resulting molded article and the impact resistance are good, and the impact resistance, which was difficult in the prior art, A graft copolymer capable of providing a thermoplastic resin composition having a good balance between flame retardancy and heat resistance, and a heat comprising the graft copolymer and a thermoplastic resin containing polystyrene and / or polyphenylene ether It aims at providing the molded product formed by shape | molding a thermoplastic resin composition and this thermoplastic resin composition.

  As a result of intensive studies to solve the above problems, the present inventor has obtained a graft copolymer obtained by graft copolymerizing an aromatic vinyl monomer to an olefin rubber-like polymer having a predetermined average particle diameter. It has been found that the thermoplastic resin containing polystyrene and / or polyphenylene ether is effective in improving the surface appearance, fluidity and impact resistance of the thermoplastic resin, and has completed the present invention.

  That is, the gist of the present invention is as follows.

[1] A graft copolymer (B) obtained by graft copolymerizing an aromatic vinyl monomer in the presence of an olefin rubber-like polymer (A) having an average particle size of 0.1 to 1.0 μm. A graft copolymer (B) having a 5% weight loss temperature of 300 ° C. or higher.

[2] The number average molecular weight (Mn) in terms of standard polystyrene measured by gel permeation chromatography (GPC) of the acetone-soluble component of the graft copolymer (B) is 10,000 to 100,000. The graft copolymer (B) according to [1].

[3] The graft according to [1] or [2], wherein the olefin rubber-like polymer (A) comprises an ethylene / α-olefin copolymer and / or an ethylene / α-olefin / non-conjugated diene copolymer. Copolymer (B).

[4] In the presence of 10 to 90 parts by mass of the olefinic rubbery polymer (A), 90 to 10 parts by mass of an aromatic vinyl monomer is graft-copolymerized (however, the olefinic rubbery polymer ( A) and the graft copolymer (B) according to any one of [1] to [3].

[5] The graft according to any one of [1] to [4], wherein the monomer component graft-copolymerized to the olefin rubber-like polymer (A) is substantially only an aromatic vinyl monomer. Copolymer (B).

[6] The graft copolymer (B) according to any one of [1] to [5], which is an improving agent for a thermoplastic resin (C) containing polystyrene and / or polyphenylene ether.

[7] The graft copolymer (B) according to [6], wherein the thermoplastic resin (C) includes polystyrene and / or polyphenylene ether and a hydrogenated styrene-based thermoplastic elastomer (D).

[8] A thermoplastic resin composition comprising the graft copolymer (B) according to any one of [1] to [7] and a thermoplastic resin (C) containing polystyrene and / or polyphenylene ether.

[9] The thermoplastic resin (C) is contained in an amount of 50 to 99.9 parts by mass with respect to the graft copolymer (B) in an amount of 0.1 to 50 parts by mass (provided that the graft copolymer (B) and the thermoplastic resin are included. (C) and 100 parts by mass in total), the thermoplastic resin composition according to [8].

[10] The thermoplastic resin composition according to [8] or [9], wherein the thermoplastic resin (C) includes polystyrene and / or polyphenylene ether and a hydrogenated styrene-based thermoplastic elastomer (D).

[11] A molded article comprising the thermoplastic resin composition according to any one of [8] to [10].

  According to the present invention, there is provided a thermoplastic resin composition containing polystyrene and / or polyphenylene ether, which has good fluidity and surface appearance and impact resistance of the resulting molded product, which has been difficult in the prior art. A thermoplastic resin composition having a good balance of impact, flame retardancy and heat resistance can be provided. Moreover, this thermoplastic resin composition can be molded under good moldability to provide a molded product having a high commercial value.

  Hereinafter, embodiments of the present invention will be described in detail.

  In the present specification, “unit” means a structural portion derived from a compound (monomer, ie, monomer) before polymerization, contained in the polymer. For example, “α-olefin unit” means It means “a structural portion derived from an α-olefin and contained in a polymer”. The content of the monomer unit of each polymer corresponds to the amount of the monomer used for the production of the polymer.

[Graft Copolymer (B)]
The graft copolymer (B) of the present invention is obtained by graft copolymerizing an aromatic vinyl monomer in the presence of an olefin rubber-like polymer (A) having an average particle size of 0.1 to 1.0 μm. The graft copolymer (B) is characterized in that the 5% weight loss temperature is 300 ° C. or higher.

<Mechanism>
Graft copolymer (B) of the present invention having a 5% weight loss temperature of a predetermined value or more obtained by graft copolymerization of an aromatic vinyl monomer to an olefin rubber-like polymer (A) having a specific average particle size The rubbery polymer is an olefinic rubbery polymer (A), so that the resulting molded article has good impact resistance, scratch resistance and cold impact resistance, and its average particle size is specific. By being in the range, the impact resistance and surface appearance of the obtained molded product can be improved, and the 5% weight loss temperature is not less than a predetermined value, so that it can be used during processing or in a high temperature environment. Discoloration and deterioration of physical properties are suppressed, and a high-quality molded product can be obtained. Further, since the graft copolymerization monomer is an aromatic vinyl monomer, the flowability and moldability of the thermoplastic resin (C) containing polystyrene and / or polyphenylene ether are improved, and the resulting molded product The surface appearance can be improved.

On the other hand, Patent Document 1 includes examples of ethylene / α-olefin copolymers and ethylene / α-olefin / non-conjugated diene copolymers as rubbery polymers, and monomers for graft copolymerization. Although an aromatic vinyl monomer is described as a component, the rubbery polymer specifically used in the examples of Patent Document 1 is polybutadiene, and there is no example using an olefinic rubbery polymer. . Further, there is no description or suggestion that an olefinic rubbery polymer is preferable among the rubbery polymers exemplified in Patent Document 1. Furthermore, as for the monomer component to be graft-copolymerized, Example 6 using only an aromatic vinyl monomer and Examples 1 to 5 using an aromatic vinyl monomer and a vinyl cyanide monomer are shown. However, in Example 6 in which only an aromatic vinyl monomer was graft-copolymerized to polybutadiene, all of the evaluation items of Izod impact value, tensile strength and surface gloss were as follows. It is inferior to Examples 1-5 which used the body together, and it can be read from the description of Patent Document 1 that the single use of the aromatic vinyl monomer is inferior in effect. From any description in Patent Document 1, an olefinic rubbery polymer is used as the rubbery polymer, and an olefinic rubbery polymer is graft copolymerized with an aromatic vinyl monomer, so that polystyrene and / or It is not suggested that the fluidity and surface appearance of the thermoplastic resin (C) containing polyphenylene ether can be improved.
In addition, in Patent Document 1, a rubbery polymer is impregnated with a monomer component, and graft copolymerization is performed using an oil-soluble pyrolysis initiator. There is a concern that the monomer component is polymerized and the graft coverage of the graft copolymer is lowered. For this reason, compatibility between the graft copolymer and the thermoplastic resin (C) containing polystyrene and / or polyphenylene ether is deteriorated, and there is a concern that the mechanical properties are lowered.

<Olefin rubber-like polymer (A)>
Examples of the olefinic rubbery polymer (A) used as the rubbery polymer in the graft copolymer (B) of the present invention include ethylene / α-olefin copolymers, ethylene / propylene / nonconjugated diene copolymers. A polymer etc. are mentioned.

  Examples of the α-olefin of the ethylene / α-olefin copolymer include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-icosene, 1 -1 type (s) or 2 or more types, such as dococene, are mentioned. Among these, a molded product obtained from the thermoplastic resin composition of the present invention obtained by blending the graft copolymer (B) of the present invention (hereinafter, sometimes simply referred to as “molded product obtained”). From the viewpoint of impact resistance, an α-olefin having 3 to 20 carbon atoms is preferable, and propylene is particularly preferable.

  The ethylene unit content of the ethylene / α-olefin copolymer is 45 to 65% by mass when the total of all the structural units constituting the ethylene / α-olefin copolymer (A) is 100% by mass. Is preferable, and 50-60 mass% is more preferable. When the ethylene unit content is within the above range, the resulting molded article has a further excellent balance of scratch resistance, impact resistance, cold impact resistance, and lubricity. In particular, when the ethylene unit content is 50 to 60% by mass, the scratch resistance, impact resistance, and cold impact resistance of the obtained molded product are further improved.

  The ethylene / propylene / non-conjugated diene copolymer is a copolymer comprising an ethylene unit, a propylene unit, and a non-conjugated diene unit as a third component. Examples of the non-conjugated diene include dicyclopentadiene, 1 type or 2 types or more, such as ethylidene norbornene, 1, 4-hexadiene, 1,5-hexadiene, 2-methyl-1,5-hexadiene, 1,4-cycloheptadiene, 1,5-cyclooctadiene, etc. are mentioned. It is done.

The mass average molecular weight (Mw) of the olefin rubber-like polymer (A) is usually 17 × 10 ^{4 to} 35 × 10 ⁴ , and preferably 26 × 10 ^{4 to} 32 × 10 ⁴ . When the mass average molecular weight (Mw) of the olefin rubber-like polymer (A) is smaller than 17 × 10 ⁴ , the resulting molded article has poor scratch resistance, impact resistance, cold impact resistance, and lubricity. It becomes. On the other hand, when the mass average molecular weight (Mw) is larger than 35 × 10 ⁴ , a thermoplastic resin composition obtained by blending the graft copolymer (B) of the present invention (hereinafter simply referred to as “the obtained thermoplasticity”). There is a tendency that the fluidity of the resin composition and the surface appearance of the obtained molded product are inferior. If the mass average molecular weight (Mw) is 26 × 10 ^{4 to} 32 × 10 ⁴ , the fluidity of the resulting thermoplastic resin composition and the surface appearance of the resulting molded product, scratch resistance, impact resistance, cold impact resistance Will be better.

  The molecular weight distribution (Mw / Mn) of the olefin rubber-like polymer (A) is 1 to 3, and preferably 1.9 to 2.5. When the molecular weight distribution (Mw / Mn) is larger than 3, the resulting molded product tends to be inferior in scratch resistance, impact resistance, cold impact resistance, and lubricity. If the molecular weight distribution (Mw / Mn) is 1.9 to 2.5, the fluidity of the resulting thermoplastic resin composition and the surface appearance, scratch resistance, and impact resistance of the resulting molded product are further improved. It becomes.

  Here, the mass average molecular weight (Mw) and the number average molecular weight (Mn) of the olefin rubber-like polymer (A) are values measured by gel permeation chromatography (GPC) and converted to standard polystyrene. Specifically, it is measured by the following method.

<Method for measuring mass average molecular weight (Mw), molecular weight distribution (Mw / Mn)>
Mass average molecular weight in terms of polystyrene using GPC (GPC: “GPC / V2000” manufactured by Waters, column: “Shodex AT-G + AT-806MS” manufactured by Showa Denko KK) and o-dichlorobenzene (145 ° C.) as a solvent. (Mw), number average molecular weight (Mn) is measured, and molecular weight distribution (Mw / Mn) is calculated.

  The manufacturing method of an olefin type rubber-like polymer (A) is not limited. For example, an ethylene / α-olefin copolymer is usually produced by polymerizing ethylene and an α-olefin using a metallocene catalyst or a Ziegler-Natta catalyst.

As a metallocene catalyst, a catalyst obtained by combining an organic compound having a cyclopentadienyl skeleton with a transition metal (zirconium, titanium, hafnium, etc.), a metallocene complex in which a halogen atom or the like is coordinated, an organoaluminum compound, an organoboron compound, etc. Is mentioned.
Examples of the Ziegler-Natta catalyst include a catalyst in which a halide of a transition metal (titanium, vanadium, zirconium, hafnium, etc.) is combined with an organic aluminum compound, an organic boron compound, or the like.

  Examples of the polymerization method include a method in which ethylene and an α-olefin are copolymerized in a solvent in the presence of the catalyst. Examples of the solvent include hydrocarbon solvents (benzene, toluene, xylene, pentane, hexane, heptane, octane, etc.). A hydrocarbon solvent may be used individually by 1 type, and 2 or more types may be mixed and used for it. Moreover, you may use the raw material alpha olefin as a solvent.

  By changing the reaction conditions such as the supply amount of ethylene, α-olefin, the type and amount of molecular weight regulators such as hydrogen, the type and amount of catalyst, the reaction temperature, and the pressure, an ethylene / α-olefin copolymer (A ) Ethylene unit content, mass average molecular weight (Mw) and molecular weight distribution (Mw / Mn) can be adjusted.

  An ethylene / propylene / non-conjugated diene copolymer can also be produced in the same manner as described above by using non-conjugated diene together with ethylene and propylene.

  By using such an olefin rubber-like polymer (A), the molded article obtained has good weather resistance and wear resistance, and a reduction in friction coefficient and squeak noise can be expected. In addition, it can be expected to suppress discoloration of molded articles and deterioration of physical properties under high-temperature environments, to reduce the amount of flame retardant added in materials for flame retardant use, and to be expected to improve electrical properties and other chemical properties.

  The olefin rubber-like polymer (A) may be an aqueous dispersion. The method for preparing the aqueous dispersion of the olefin rubber-like polymer (A) is not limited. For example, an aqueous medium containing an emulsifier is prepared by melt-kneading the olefin-based rubber-like polymer (A) with a known melt-kneading means (kneader, Banbury mixer, multi-screw extruder, etc.), applying mechanical shearing force, and dispersing it. The olefin rubber-like polymer (A) is dissolved in a hydrocarbon solvent (pentane, hexane, heptane, benzene, toluene, xylene, etc.) together with an emulsifier, added to an aqueous medium, and emulsified sufficiently. And a method of distilling off the hydrocarbon solvent. In preparing the aqueous dispersion of the olefin rubber-like polymer (A), an emulsifier, an acid-modified olefin polymer and the like may be added as other components.

As an emulsifier, a well-known thing is mentioned, For example, 1 type (s) or 2 or more types, such as a long-chain alkyl carboxylate, a sulfosuccinic-acid alkylester salt, and an alkylbenzenesulfonate, are mentioned.
The amount of the emulsifier added can suppress thermal coloring of the resulting thermoplastic resin composition, and can easily control the particle size of the olefin rubber-like polymer (A) in the aqueous dispersion. 1-8 mass parts is preferable with respect to 100 mass parts of union (A).

  Examples of the acid-modified olefin polymer include those obtained by modifying an olefin polymer having a mass average molecular weight of 1,000 to 5,000 (polyethylene, polypropylene, etc.) with a compound having a functional group (such as an unsaturated carboxylic acid compound). It is done. Examples of the unsaturated carboxylic acid compound include acrylic acid, maleic acid, itaconic acid, maleic anhydride, itaconic anhydride, maleic acid monoamide, and the like. The acid value of the acid-modified olefin polymer is preferably about 10 to 50 mg-KOH / g. An acid-modified olefin polymer may be used individually by 1 type, and may be used in combination of 2 or more type.

  The addition amount of the acid-modified olefin polymer is preferably 1 to 40 parts by mass with respect to 100 parts by mass of the olefin rubber-like polymer (A). When the addition amount of the acid-modified olefin polymer is within the above range, the balance between scratch resistance and impact resistance of the obtained molded product is further improved.

The method for adding the acid-modified olefin polymer is not limited. For example, when the olefin rubber-like polymer (A) is used after being crosslinked as described later, the olefin rubber-like polymer (A) and the acid-modified olefin polymer may be mixed and then crosslinked. The olefin rubber-like polymer (A) and the acid-modified olefin polymer may be mixed after being subjected to a crosslinking treatment.
The mixing method of the olefin rubber-like polymer (A) and the acid-modified olefin polymer is not limited. Examples of the mixing method include a melt kneading method using a kneader, a Banbury mixer, a multi-screw extruder and the like.

  In addition, as an aqueous medium of the aqueous dispersion of the olefin rubber-like polymer (A), water or an aqueous solution of a basic substance can be used.

  The olefin rubber-like polymer (A) may also be subjected to a crosslinking treatment.

  By cross-linking the olefin rubber-like polymer (A), the resulting molded article has an even better balance of scratch resistance, impact resistance, cold impact resistance, color development, and lubricity.

  The gel content of the cross-linked olefin-based rubbery polymer (A) is 35 to 75% by mass from the viewpoint of the balance of scratch resistance, impact resistance, cold impact resistance, color development, and lubricity of the obtained molded product. Is preferable, 40-70 mass% is more preferable, 45-65 mass% is especially preferable. A specific method for measuring the gel content of the crosslinked olefin-based rubbery polymer (A) is as follows.

<Method for measuring gel content>
0.5 g of a coagulated powder sample [Cx] obtained by adding dilute sulfuric acid to an aqueous dispersion of the crosslinked olefin-based rubber-like polymer (A), coagulating, washing with water and drying is placed in 200 mL of 110 ° C. toluene. Immerse for 5 hours, then filter through a 200 mesh wire net, dry the residue, measure the mass of the dried product [Cy], and from the following formula (1), the crosslinked olefin rubber-like polymer (A) Obtain the gel content.
Gel content rate (%) = dry substance amount [Cy] (g) / coagulated powder sample mass [Cx] (g)
× 100 (1)

  The crosslinking treatment of the olefin rubber-like polymer (A) can be performed by a known method. As a method of crosslinking treatment, a method of carrying out a crosslinking treatment by adding an organic peroxide and, if necessary, a polyfunctional compound to the olefin rubber-like polymer (A); (b) by ionizing radiation Examples include a method for performing a crosslinking treatment. The method (a) is preferred from the viewpoint of impact resistance and color developability of the obtained molded product.

  Specifically, as the method (a), an organic peroxide and, if necessary, a polyfunctional compound are added to the olefin rubber-like polymer (A) or an aqueous dispersion thereof and heated. Methods and the like.

The gel content of the crosslinked olefin-based rubbery polymer (A) can be adjusted by adjusting the addition amount of organic peroxide and polyfunctional compound, heating temperature, heating time, and the like.
The heating temperature varies depending on the type of organic peroxide. The heating temperature is preferably in the range of −5 ° C. to + 30 ° C. with respect to the 10-hour half-life temperature of the organic peroxide.
The heating time is preferably 3 to 15 hours.

  The organic peroxide is for forming a crosslinked structure in the olefin rubber-like polymer (A). Examples of the organic peroxide include peroxyester compounds, peroxyketal compounds, dialkyl peroxide compounds, hydroperoxide compounds, and the like. An organic peroxide may be used individually by 1 type, and may be used in combination of 2 or more type.

  Specific examples of the peroxyester compound include α, α′-bis (neodecanoylperoxy) diisopropylbenzene, cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecano. 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxy Pivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexane, 1-cyclohexyl- 1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy-2-hexyl Hexanoate, t-butyl peroxy 2-hexyl hexanoate, t-butyl peroxy isobutyrate, t-hexyl peroxy isopropyl monocarbonate, t-butyl peroxy maleic acid, t-butyl peroxy 3, 5, 5-trimethylhexanoate, t-butylperoxylaurate, 2,5-dimethyl-2,5-bis (m-toluoylperoxy) hexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy 2-ethylhexyl monocarbonate, t-hexylperoxybenzoate, 2,5-dimethyl-2,5-bis (benzoylperoxy) hexane, t-butylperoxyacetate, t-butylperoxy-m-toluoylbenzoate, t-Butylperoxybenzoe , Bis (t-butylperoxy) isophthalate.

  Specific examples of the peroxyketal compound include 1,1-bis (t-hexylperoxy) 3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis. (T-butylperoxy) 3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) cyclododecane, 2,2-bis (T-butylperoxy) butane, n-butyl 4,4-bis (t-butylperoxy) valerate, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane and the like. .

  Specific examples of the dialkyl peroxide compound include α, α′-bis (t-butyl peroxide) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane. , T-butylcumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3, and the like.

  Specific examples of hydroperoxide compounds include cumene hydroperoxide, t-butyl hydroperoxide, diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, etc. Is mentioned.

  As the organic peroxide, dialkyl such as dicumyl peroxide, t-butylcumyl peroxide, di-t-butyl peroxide and the like from the viewpoint that the gel content of the crosslinked olefin-based rubbery polymer (A) can be easily adjusted. Peroxide compounds are particularly preferred.

  The amount of the organic peroxide added is 100 parts by mass of the olefin rubber polymer (A) because the gel content of the crosslinked olefin rubber polymer (A) can be easily adjusted to the range of 35 to 75% by mass. The amount is preferably 0.1 to 5 parts by mass.

  The polyfunctional compound is used in combination with an organic peroxide as necessary in order to adjust the gel content of the crosslinked olefin-based rubbery polymer (A). Examples of the polyfunctional compound include divinylbenzene, allyl methacrylate, ethylene glycol dimethacrylate, 1,3-butylene dimethacrylate, tetraethylene glycol diacrylate, triallyl cyanurate, triallyl isocyanurate, pentaerythritol tetraacrylate, and the like. From the viewpoint of easily adjusting the gel content, divinylbenzene is preferable. A polyfunctional compound may be used individually by 1 type, and may be used in combination of 2 or more type.

  The addition amount of the polyfunctional compound is based on 100 parts by mass of the olefin rubber polymer (A) because the gel content of the crosslinked olefin rubber polymer (A) can be easily adjusted to 35 to 75% by mass. 10 parts by mass or less is preferable.

  The average particle diameter of the olefinic rubbery polymer (A) used in the present invention is 0.1 to 1.0 μm, preferably 0.2 to 0.9 μm, more preferably 0.2 to 0.8 μm, 0 .3 to 0.7 μm is particularly preferable. When the average particle diameter is within the above range, the resulting molded article has excellent impact resistance and surface appearance.

  Here, the specific measuring method of the average particle diameter of the olefin rubber-like polymer (A) is as shown in the section of the examples below.

<Graft copolymer (B)>
The graft copolymer (B) of the present invention can be obtained by graft copolymerization of an aromatic vinyl monomer in the presence of the olefinic rubbery polymer (A). As described above, the olefin rubber-like polymer (A) may be crosslinked or not.

  Examples of the aromatic vinyl monomer include styrene, α-methyl styrene, o-methyl styrene, p-methyl styrene, ethyl styrene, vinyl toluene, vinyl xylene, methyl-α-methyl styrene, t-butyl styrene, divinyl. Chlorinated styrene such as benzene, 1,1-diphenylstyrene, N, N-diethyl-p-aminomethylstyrene, N, N-diethyl-p-aminoethylstyrene, vinylnaphthalene, vinylpyridine, monochlorostyrene, dichlorostyrene; Examples include brominated styrene such as monobromostyrene and dibromostyrene; monofluorostyrene and the like. Among them, styrene and α-methylstyrene are preferable. Only one type of aromatic vinyl monomer may be used, or two or more types may be used in combination.

  By using an aromatic vinyl monomer as a monomer for graft copolymerization with the olefin rubber-like polymer (A), the resulting thermoplastic resin composition has good fluidity, and the molded product obtained The surface appearance is good. Moreover, the compatibility of the graft copolymer (B) and the thermoplastic resin (C) containing polystyrene and / or polyphenylene ether is improved by using an aromatic vinyl monomer.

  The graft copolymer (B) is obtained by graft copolymerization of 90 to 10 parts by mass of an aromatic vinyl monomer in the presence of 10 to 90 parts by mass of the olefin rubber-like polymer (A). Preferably, those obtained by graft copolymerization of 80 to 20 parts by mass of an aromatic vinyl monomer in the presence of 20 to 80 parts by mass of the olefinic rubbery polymer (A) are more preferable. What is obtained by graft copolymerization of 75 to 25 parts by mass of an aromatic vinyl monomer in the presence of 25 to 75 parts by mass of the polymer (A) is more preferable, and the olefin rubber-like polymer (A) 30 What was obtained by graft-copolymerizing 70-30 mass parts of aromatic vinyl monomers in presence of -70 mass parts is especially preferable. However, the total of the olefinic rubbery polymer (A) and the aromatic vinyl monomer is 100 parts by mass. If the ratio of the olefinic rubbery polymer (A) is within the above range, the productivity of the graft copolymer (B) is good, and the impact resistance and surface appearance of the resulting molded product are good. . Further, the obtained molded article has good weather resistance and wear resistance, and can be expected to reduce the friction coefficient and squeak noise.

The graft copolymer (B) of the present invention is obtained by graft copolymerizing substantially only an aromatic vinyl monomer as a graft copolymer monomer component to the olefin rubber-like polymer (A). It is characterized by that.
Here, “substantially graft copolymerized with only an aromatic vinyl monomer” means that the aromatic vinyl monomer in 100 parts by mass of the monomer component to be graft copolymerized with the olefin rubber-like polymer (A). It means that the proportion of the body exceeds 95 parts by mass, preferably the proportion of the aromatic vinyl monomer is 99 parts by mass or more, more preferably 99.5 parts by mass or more, still more preferably 99.9 parts by mass or more. In particular, it is particularly preferable that all of the monomer components graft-copolymerized to the olefin rubber-like polymer (A) are composed only of aromatic vinyl monomers.

  The method for producing the graft copolymer (B) is not limited, and is produced by a known polymerization method (emulsion polymerization method, solution polymerization method, suspension polymerization method, bulk polymerization method).

  As a method for producing the graft copolymer (B) by the emulsion polymerization method, for example, an aromatic vinyl monomer is mixed with an organic peroxide, and then the aromatic vinyl monomer is converted into an olefin rubber-like polymer ( Examples thereof include a method of continuously adding A) or an aqueous dispersion of the crosslinked olefin-based rubbery polymer (A). The organic peroxide is preferably used as a redox initiator that combines an organic peroxide, a transition metal, and a reducing agent. In the polymerization, a chain transfer agent, an emulsifier or the like may be used depending on the situation.

The redox initiator does not require the polymerization reaction conditions to be at a high temperature, avoids deterioration of the olefinic rubbery polymer (A) or the crosslinked olefinic rubbery polymer (A), etc. A combination of an organic peroxide and a ferrous sulfate-chelating agent-reducing agent is preferable from the viewpoint of avoiding a decrease in impact resistance.
Examples of the organic peroxide include cumene hydroperoxide, diisopropylbenzene hydroperoxide, t-butyl hydroperoxide and the like.
The redox initiator is more preferably composed of cumene hydroperoxide, ferrous sulfate, sodium pyrophosphate and dextrose or fructose.

As chain transfer agents, mercaptans (octyl mercaptan, n- or t-dodecyl mercaptan, n-hexadecyl mercaptan, n- or t-tetradecyl mercaptan, etc.), allyl compounds (allylsulfonic acid, methallylsulfonic acid, these Sodium salts, etc.), α-methylstyrene dimers, and the like, and mercaptans are preferred from the viewpoint of easy adjustment of the molecular weight. A chain transfer agent may be used individually by 1 type, and may be used in combination of 2 or more type.
The method for adding the chain transfer agent may be any of batch, split, and continuous.
The addition amount of the chain transfer agent is preferably 2.0 parts by mass or less with respect to 100 parts by mass of the aromatic vinyl monomer.

Examples of the emulsifier include anionic surfactants, nonionic surfactants, and amphoteric surfactants.
Examples of the anionic surfactants include higher alcohol sulfates, alkylbenzene sulfonates, fatty acid sulfonates, phosphate salts, fatty acid salts, and amino acid derivative salts.
Examples of nonionic surfactants include ordinary polyethylene glycol alkyl ester types, alkyl ether types, and alkyl phenyl ether types.
Examples of the amphoteric surfactant include those having a carboxylate salt, sulfate ester salt, sulfonate salt, phosphate ester salt and the like in the anion portion and amine salts and quaternary ammonium salts in the cation portion.

  The amount of the emulsifier added is preferably 10 parts by mass or less with respect to 100 parts by mass of the aromatic vinyl monomer.

The graft copolymer (B) obtained by the emulsion polymerization method is in a state of being dispersed in an aqueous medium. As a method for recovering the graft copolymer (B) from the aqueous dispersion containing the graft copolymer (B), for example, a precipitation agent is added to the aqueous dispersion, heated and stirred, and then the precipitation agent is separated. And a precipitation method in which the precipitated graft copolymer (B) is washed with water, dehydrated and dried.
Examples of the precipitating agent include aqueous solutions of sulfuric acid, acetic acid, calcium chloride, magnesium sulfate, and the like. A precipitation agent may be used individually by 1 type, and may be used in combination of 2 or more type.
You may add antioxidant to the aqueous dispersion containing a graft copolymer (B) as needed.

  The graft ratio of the graft copolymer (B) of the present invention is preferably 20 to 100% by mass from the viewpoint of compatibility with the thermoplastic resin (C) described later. The specific method for measuring the graft ratio of the graft copolymer (B) is as shown in the Examples section below.

The 5% weight loss temperature of the graft copolymer (B) of the present invention is 300 ° C or higher, preferably 325 ° C or higher, more preferably 350 ° C or higher, further preferably 375 ° C or higher, particularly 400 ° C or higher. preferable. If the 5% weight loss temperature is equal to or higher than the above temperature, it can be expected to suppress discoloration or deterioration of physical properties during processing or in a high temperature environment. The 5% weight loss temperature is an index of the heat resistance of the graft copolymer (B), and the graft copolymer (B) of the present invention is obtained by the fact that the rubber-like polymer is the olefin rubber-like polymer (A). The 5% weight loss temperature can be increased.
A specific method for measuring the 5% weight loss temperature of the graft copolymer (B) is as shown in the Examples section below.

  The number average molecular weight (Mn) in terms of standard polystyrene measured by GPC of the acetone soluble component of the graft copolymer (B) of the present invention is 10,000 to 100,000, and 12,000 to 80. 15,000 is preferable, 14,000 to 70,000 is more preferable, and 15,000 to 50,000 is particularly preferable. If the number average molecular weight (Mn) of the acetone-soluble component of the graft copolymer (B) is within the above range, the compatibility with the thermoplastic resin (C) described later is good, and the resulting thermoplastic resin composition and The appearance, impact resistance, and tensile elongation of the molded product are improved. A specific method for measuring the number average molecular weight (Mn) of the acetone-soluble component of the graft copolymer (B) is as shown in the Examples section below.

[Thermoplastic resin composition]
The thermoplastic resin composition of the present invention comprises the above-described graft copolymer (B) of the present invention and a thermoplastic resin (C) containing polystyrene and / or polyphenylene ether.

<Thermoplastic resin (C)>
The thermoplastic resin (C) contains at least one thermoplastic resin selected from polystyrene (general-purpose polystyrene: GPPS) and polyphenylene ether.

  By blending the graft copolymer (B) of the present invention with the above-mentioned thermoplastic resin (C) containing polystyrene and / or polyphenylene ether, the thermoplastic resin has good impact resistance and good surface appearance and fluidity. A resin composition is obtained. In addition, by blending the graft copolymer (B) of the present invention with polyphenylene ether, it is possible to suppress the degradation of flame retardancy and electrical properties of polyphenylene ether, and the blending amount of flame retardants such as phosphorus compounds and halogen compounds. Can be suppressed. Therefore, a thermoplastic resin composition having a good balance of impact resistance, flame retardancy, and electrical properties and good heat resistance can be obtained. In any case, it can be expected to suppress deterioration of physical properties and surface appearance under a high temperature environment.

<Polystyrene>
As the thermoplastic resin (C) used in the thermoplastic resin composition of the present invention, a commercially available product can be purchased and used. Specific examples include CR-2500, CR-3500, CR-2600 manufactured by DIC, HF77, 697 manufactured by PS Japan, and G100C, G200C, G210C manufactured by Toyo Styrene.

  In the present invention, polystyrene may be used alone or in combination of two or more.

<Polyphenylene ether>
The polyphenylene ether (PPE) as the thermoplastic resin (C) used in the thermoplastic resin composition of the present invention is a polymer having a structural unit represented by the following formula in the main chain, and is a homopolymer or a copolymer. Any of polymers may be used.

(In the formula, two R ^{a s} each independently represent a hydrogen atom, a halogen atom, a primary or secondary alkyl group, an aryl group, an aminoalkyl group, a haloalkyl group, a hydrocarbonoxy group, or a halohydrocarbonoxy group. Each of the two R ^{b s} independently represents a hydrogen atom, a halogen atom, a primary or secondary alkyl group, an aryl group, a haloalkyl group, a hydrocarbonoxy group, or a halohydrocarbonoxy group. However, both R ^a are not hydrogen atoms.)

R ^a and R ^b are preferably a hydrogen atom, a primary or secondary alkyl group, or an aryl group. Preferable examples of the primary alkyl group include methyl group, ethyl group, n-propyl group, n-butyl group, n-amyl group, isoamyl group, 2-methylbutyl group, 2,3-dimethylbutyl group, 2 -, 3- or 4-methylpentyl group or heptyl group may be mentioned. Preferable examples of the secondary alkyl group include isopropyl group, sec-butyl group, and 1-ethylpropyl group. In particular, ^Ra is preferably ^a primary or secondary alkyl group having 1 to 4 carbon atoms or a phenyl group. R ^b is preferably a hydrogen atom.

  Suitable homopolymers of polyphenylene ether resins include, for example, poly (2,6-dimethyl-1,4-phenylene ether), poly (2,6-diethyl-1,4-phenylene ether), poly (2, 2 such as 6-dipropyl-1,4-phenylene ether), poly (2-ethyl-6-methyl-1,4-phenylene ether), poly (2-methyl-6-propyl-1,4-phenylene ether), etc. , 6-dialkylphenylene ether polymer. Examples of the copolymer include 2,6-dimethylphenol / 2,3,6-trimethylphenol copolymer, 2,6-dimethylphenol / 2,3,6-triethylphenol copolymer, and 2,6-diethylphenol. 2,6-dialkylphenol / 2,3,6-trialkylphenol copolymer such as 2,3,6-trimethylphenol copolymer and 2,6-dipropylphenol / 2,3,6-trimethylphenol copolymer Polymer, graft copolymer obtained by graft polymerization of styrene to poly (2,6-dimethyl-1,4-phenylene ether), styrene to 2,6-dimethylphenol / 2,3,6-trimethylphenol copolymer And a graft copolymer obtained by graft polymerization.

  As the polyphenylene ether in the present invention, poly (2,6-dimethyl-1,4-phenylene ether) and 2,6-dimethylphenol / 2,3,6-trimethylphenol random copolymer are particularly preferable.

<Hydrogenated styrene-based thermoplastic elastomer (D)>
The above-mentioned thermoplastic resin (C) containing polystyrene and / or polyphenylene ether can be further blended with a hydrogenated styrene-based thermoplastic elastomer (D).

  Hydrogenated styrene thermoplastic elastomer (D) is a block copolymer obtained by hydrogenating a block copolymer of styrene and a conjugated diene compound, that is, a block copolymer comprising a polystyrene block and a conjugated diene compound polymer block. It can be preferably used.

  In the hydrogenated styrene-based thermoplastic elastomer (D) component, the hydrogenation rate of unsaturated bonds derived from the conjugated diene compound by hydrogenation is preferably 60% or more, more preferably 80% or more, and still more preferably 95%. That's it.

The structure of the block copolymer of the hydrogenated styrene-based thermoplastic elastomer (D) component before hydrogenation is the same as that of the block copolymer of styrene and a conjugated diene compound. In the case of a hydrogenated hydrogenated block copolymer, when the styrene block chain is represented by S and the diene compound block chain is represented by B, S-B-S, S-B-S-B, (S-B-) ₄ A structure having —S, S—B—S—B—S, or the like can be given.

The microstructure of the diene compound polymer block can be arbitrarily selected.
The amount of vinyl bonds (total of 1,2-vinyl bonds and 3,4-vinyl bonds) is the total of diene compound polymer bonds (1,2-vinyl bonds, 3,4-vinyl bonds and 1,4-bonds). Is preferably 2 to 60%, more preferably 8 to 40%.

  The number average molecular weight (Mn) of the hydrogenated styrene-based thermoplastic elastomer (D) is preferably 150,000 to 350,000. When the number average molecular weight (Mn) of the hydrogenated styrene-based thermoplastic elastomer (D) is 150,000 or more, the impact resistance of a thermoplastic resin composition containing the number average molecular weight (Mn) is excellent. The impact resistance of the thermoplastic resin composition is improved in proportion to the number average molecular weight (Mn) of the hydrogenated styrene-based thermoplastic elastomer (D). When it is 350,000 or less, the load at the time of melt extrusion of the thermoplastic resin composition is reduced, excellent processing fluidity is obtained, and the hydrogenated styrene-based thermoplastic elastomer (D) component is added. It can be sufficiently dispersed in the thermoplastic resin composition.

  When the hydrogenated styrene-based thermoplastic elastomer (D) is a hydrogenated block copolymer obtained by hydrogenating a block copolymer of styrene and a conjugated diene compound, the number average molecular weight of at least one styrene polymer block chain (Mn) is preferably 15,000 or more, more preferably 20,000 or more and 50,000 or less. More preferably, the number average molecular weight (Mn) of all styrene polymer block chains is 15,000 or more.

  In addition, the said number average molecular weight (Mn) can be measured by GPC, and uses the value of styrene conversion.

  When the hydrogenated styrene thermoplastic elastomer (D) is a hydrogenated block copolymer obtained by hydrogenating a block copolymer of styrene and a conjugated diene compound, the styrene polymer block is a hydrogenated styrene thermoplastic elastomer. The range occupied by (D) (hereinafter referred to as “styrene content”) is not particularly limited as long as the number average molecular weight of the styrene polymer block chain is within the above range, but from the viewpoint of the balance between fluidity and impact resistance. Therefore, it is preferably in the range of 10 to 70% by mass, more preferably 20 to 50% by mass.

As the hydrogenated styrene-based thermoplastic elastomer (D), two or more hydrogenated block copolymers having different compositions and structures can be used in combination.
For example, a combined use of a hydrogenated block copolymer having a styrene content of 50% by mass or more and a hydrogenated block copolymer having a styrene content of 30% by mass or less, a combined use of hydrogenated block copolymers having different molecular weights, or a conjugate with styrene. A hydrogenated random block copolymer obtained by hydrogenating a block copolymer containing a random copolymer block of diene can also be used in combination.

<Contents of graft copolymer (B) and thermoplastic resin (C)>
The content of the graft copolymer (B) and the thermoplastic resin (C) in the thermoplastic resin composition of the present invention is 0.1 to 50 parts by mass of the graft copolymer (B). (C) 50-99.9 mass parts are preferable, and 51-99 mass parts of thermoplastic resins (C) are more preferable with respect to 1-49 mass parts of graft copolymers (B), and graft copolymer (B ) 52-98 parts by mass of the thermoplastic resin (C) is more preferable with respect to 2-48 parts by mass, and the thermoplastic resin (C) 53-97 with respect to 3-47 parts by mass of the graft copolymer (B). Part by mass is particularly preferred. However, the total of the graft copolymer (B) and the thermoplastic resin (C) is 100 parts by mass. When the content ratio of the graft copolymer (B) and the thermoplastic resin (C) is within the above range, the impact resistance and surface appearance of the obtained molded product are more excellent.

  In addition, content of hydrogenated styrene-type thermoplastic elastomer (D) is 0-35 mass% in the total 100 mass% of a thermoplastic resin (C), 1-30 mass% is more preferable, 2-20 mass% Is particularly preferred. When the content of the hydrogenated styrene-based thermoplastic elastomer (D) is in the above range, the resulting thermoplastic resin composition and molded article are excellent in impact resistance and fluidity.

<Other ingredients>
In the thermoplastic resin composition of the present invention, other thermoplastic resins and various additives other than polystyrene, polyphenylene ether and hydrogenated styrene-based thermoplastic elastomer (D) are blended to such an extent that the effects of the present invention are not impaired. Can do.

(Other thermoplastic resins)
Examples of other thermoplastic resins include ABS resin, ASA resin, AES resin, styrene thermoplastic elastomer other than hydrogenated styrene thermoplastic elastomer (D), polycarbonate, polyvinyl chloride, and ethylene-vinyl acetate copolymer. , Polyarylate, liquid crystal polyester, polyethylene, fluororesin, polyacetal, polypropylene, polyamide (for example, nylon), polyphenylene sulfide, and the like.

  In addition, when blending these other thermoplastic resins, the thermoplastic resin containing polystyrene and / or polyphenylene ether or further hydrogenated styrene-based thermoplastic elastomer (D) by the graft copolymer (B) of the present invention. In order to effectively obtain the above-described effect on (C), the ratio of the other thermoplastic resin in the total 100 parts by mass of the thermoplastic resin (C) is preferably 30 parts by mass or less, particularly preferably 25 parts by mass or less. .

(Various additives)
The thermoplastic resin composition of the present invention includes hindered phenol-based, sulfur-containing organic compound-based and phosphorus-containing organic compound-based antioxidants, phenol-based and acrylate-based heat stabilizers, monostearyl as necessary. Transesterification inhibitors such as a mixture of acid phosphate and distearyl acid phosphate, UV absorbers such as benzotriazole, benzophenone and salicylate, light stabilizers such as organic nickel and hindered amines, etc. Various stabilizers, lubricants such as higher fatty acid metal salts, higher fatty acid amides, plasticizers such as phthalates and phosphates, polybromodiphenyl ether, tetrabromobisphenol-A, brominated epoxy oligomers and brominated polycarbonate Halogen-containing compounds such as oligomers, phosphorus compounds, Flame retardants - flame retardant aid such as antimony oxide, may be added carbon black, titanium oxide, pigments and dyes.

[Molding]
The molded article of the present invention can be obtained by molding the thermoplastic resin composition of the present invention by a known molding method.
Examples of the molding method include injection molding, press molding, extrusion molding, vacuum molding, and blow molding.

  The molded article of the present invention formed by molding the thermoplastic resin composition of the present invention is excellent in surface appearance (surface gloss) and impact resistance, and can be effectively applied to a wide range of uses. Applications of the molded article of the present invention include food containers, stationery, miscellaneous goods and the like.

  In particular, the molded product of the present invention formed by molding a thermoplastic resin composition containing polyphenylene ether as the thermoplastic resin (C) can be used as a component in an electrical component. Examples of the electrical parts include industrial machines such as office machines, measuring instruments, chassis, internal parts of electrical equipment, home appliance related power adapters, recording media and their drives, sensor equipment, terminal blocks, energy Electrical and electronic parts used in secondary batteries, fuel cells, solar power generation (solar cells), solar thermal power generation, geothermal power generation, wind power generation, smart meters, etc. in the environmental field, electrical components constituting power transmission facilities, cable terminals, automobiles Examples include parts. Among them, it is particularly suitable as a connector for a photovoltaic power generation module such as a connector for a photovoltaic power generation module, a junction box for a solar battery module, or a component for a hybrid vehicle or an electric vehicle.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited to a following example. In the following examples, “%” and “part” are based on mass unless otherwise specified.

[Measurement and evaluation method]
Various measurements and evaluation methods in the following examples and comparative examples are as follows.

<Measurement of average particle diameter>
A volume average particle diameter (MV) measured using pure water as a measurement solvent was used as an average particle diameter using Microtrac (“Nanotrack 150” manufactured by Nikkiso Co., Ltd.).
In addition, the average particle diameter of the olefin rubber-like polymer (A) dispersed in the aqueous dispersion or the crosslinked olefin rubber-like polymer (A) is the same as that of the olefin rubber-like polymer in the thermoplastic resin composition. It has been confirmed by electron microscope image analysis that the average particle size of the coalesced (A) and the crosslinked olefin-based rubbery polymer (A) is shown.

<Measurement of graft ratio and average molecular weight of acetone-soluble component>
1 g of the graft copolymer (B) is added to 80 mL of acetone and heated under reflux for 3 hours. The obtained suspension acetone solution is centrifuged at 14,000 rpm at 14,000 rpm in a centrifuge (“CR21E” manufactured by Hitachi Koki Co., Ltd.). Centrifugation was performed for a minute to separate a precipitation component (acetone insoluble component) and an acetone solution (acetone soluble component).

Graft rate calculation:
The precipitation component (acetone-insoluble component) was dried and its mass (Y (g)) was measured, and the graft ratio was calculated from the following formula (2). In Formula (2), Y is the mass (g) of the acetone-insoluble component of the graft copolymer (B), and X is the total mass (g) of the graft copolymer (B) used when Y is determined. The rubber fraction is the solid content of the α-olefin copolymer (A) or the crosslinked olefin rubber polymer (A) of the graft copolymer (B).
Graft rate (%) = {(Y-X × rubber fraction) / X × rubber fraction} × 100

Measurement of average molecular weight of acetone soluble components:
The acetone solution (acetone soluble component) was filtered with a glass filter, and the obtained filtrate was concentrated to dryness with an evaporator. The remaining solid was dissolved in tetrahydrofuran, and GPC (GPC: “GPC / V2000” manufactured by Waters, column: “Shodex AT-G + AT-806MS” manufactured by Showa Denko KK) was used to calculate the weight average molecular weight in terms of polystyrene (Mw). ), Number average molecular weight (Mn) and molecular weight distribution (Mw / Mn) were measured.

<Measurement of 5% weight loss temperature>
Using a differential thermal balance (“TG8120” manufactured by Rigaku Corporation), the measurement was performed under a nitrogen atmosphere under a temperature increase rate of 10 ° C./min.

<Measurement of melt volume rate>
The pellets of the thermoplastic resin composition were measured using a melt indexer (F-F01 manufactured by Toyo Seiki Seisakusho Co., Ltd.) under conditions of cylinder temperature: 220 ° C. and load: 5.0 kg.

<Measurement of surface gloss>
Using a digital variable gloss meter (UGV-5D manufactured by Suga Test Instruments Co., Ltd.), the gloss value at the center of the test piece (length 100 mm, width 100 mm, thickness 2 mm) obtained by injection molding 1 is the incident angle 60 °. Measured with

<Evaluation of impact resistance: Charpy impact test>
Using the test piece for measuring Charpy impact strength obtained by injection molding 2, a Charpy impact test (notched) was performed under the condition of 23 ° C. according to ISO 179 standard, and Charpy impact strength was measured.

<Evaluation of heat resistance: deflection temperature under load>
Using the test specimen for measuring the deflection temperature under load obtained by injection molding 2, the deflection temperature under load was measured by the flatwise method according to the ISO75 standard. The load was 1.8 MPa.

<Evaluation of tensile elongation>
Using the test piece for measuring tensile elongation obtained by injection molding 2, the tensile elongation was measured in accordance with IS527 standard.

<Combustion test>
Using the test piece for the combustion test obtained by the injection molding 3, a vertical test (V-test) is performed according to the UL94 combustion test standard, and the conforming one is judged as “flame retardant”. Marked the rank. In addition, V-0 has the best combustion rank from the combustion seconds and combustion forms described in the test standard, and then V-1 and V-2 in that order.

[Use ingredients]
In the following examples, the graft copolymer (B-1) produced as follows, the commercially available graft copolymers (B-2) and (B-3), and the thermoplastic resin (C), hydrogen The added styrenic thermoplastic elastomer (D) was used.

<Preparation of aqueous dispersion of olefin rubber-like polymer (A)>
100 parts of EPDM (Tafmer TP3180 manufactured by Mitsui Chemicals, Inc.), 12 parts of low molecular weight modified polyethylene (High Wax 2203A, Mitsui Chemicals, Inc., mass average molecular weight; 2700, acid value; 30 mg-KOH / g), and semi-cured beef tallow 2.4 parts of fatty acid potassium soap (KS soap manufactured by Kao Corporation) was mixed. Next, the mixture was continuously supplied from the hopper of a twin screw extruder (“PCM-30” manufactured by Ikegai Co., Ltd.), and a 14% aqueous solution of potassium hydroxide was continuously supplied at a heating temperature of 200 ° C. The melt was extruded by melt kneading. Subsequently, the melt was continuously supplied to a cooling single screw extruder attached to the tip of the extruder and cooled to 90 ° C. The taken-out solid was poured into warm water at 80 ° C. and continuously dispersed to obtain an aqueous dispersion of an olefin rubber-like polymer (A) having an average particle size of 0.45 μm.

<Crosslinking treatment of olefin rubber-like polymer (A)>
Into a reaction kettle equipped with a stirrer, the aqueous dispersion (100 parts in terms of solid content) of the above olefin rubber-like polymer (A) is added, distilled water is added so that the solid content concentration is 35%, and organic peroxidation is performed. As a product, 1.0 part of t-butyl hydroperoxide and 1.0 part of divinylbenzene as a polyfunctional compound were added and reacted at 130 ° C. for 5 hours to obtain a crosslinked olefin rubbery heavy polymer having a gel content of 60% by mass. Combined (A) was prepared.

<Graft copolymer (B-1)>
In a reaction vessel equipped with a stirrer, put the crosslinked olefin rubber-like polymer (A) (50 parts in terms of solid content) and 1.4 parts of KS soap, and add distilled water so that the solid content concentration becomes 30%. 0.006 part of ferrous sulfate, 0.3 part of tetrasodium pyrophosphate and 0.35 part of fructose were added, and the temperature of the content liquid was 80 ° C. 50 parts of styrene and 0.6 part of cumene hydroperoxide, 1.0 part of KS soap and 0.14 part of potassium hydroxide are continuously supplied for 210 minutes, the temperature of the content liquid is kept at 80 ° C., and emulsion polymerization is carried out. went. After the polymerization, an antioxidant is added to the aqueous dispersion containing the graft copolymer, solids are precipitated with sulfuric acid, and after washing, dehydration and drying, the powdered graft copolymer (B- 1) was obtained.
The graft ratio of the graft copolymer (B-1) is 80.8%, the mass average molecular weight (Mw) of the acetone-soluble component is 27,000, the number average molecular weight (Mn) is 17,000, and the molecular weight distribution. (Mw / Mn) was 1.6. The 5% weight loss temperature was 400 ° C.

<Graft copolymer (B-2)>
ABS graft copolymer: RESIN (registered trademark) B602N (rubber content: 65%) manufactured by UMGABS (for comparative example)

<Graft copolymer (B-3)>
HIPS: H9152 (for comparative example) manufactured by PS Japan

<Thermoplastic resin (C)>
<C-1> GPPS: CR-2600 manufactured by DIC Corporation
<C-2> PPE: Mitsubishi Engineering Plastics Iupiace PX-100F

<Hydrogenated styrene-based thermoplastic elastomer (D)>
SEBS: Kuraray Septon 8006 (styrene content: 33% by mass, mass average molecular weight (Mw): 280,000, number average molecular weight (Mn): 260,000)

[Examples 1-4, Comparative Examples 1-3]
<Melt-kneading 1>
Graft copolymer (B-1) or graft copolymer (B-2) and thermoplastic resin (C) were added in the formulation shown in Table 1, and a twin-screw extruder (apparatus: manufactured by Nippon Steel Works, Ltd. “ TEX28V ”) was granulated at a cylinder temperature of 220 ° C. and a screw rotation speed of 250 rpm to obtain pellets of a thermoplastic resin composition.

[Examples 5 to 9, Comparative Examples 4 and 5]
<Melting and kneading 2>
Graft copolymer (B), thermoplastic resin (C) and hydrogenated styrene thermoplastic elastomer (D) were added in the formulation shown in Table 2, and a twin screw extruder (equipment: “KTX30 manufactured by Kobe Steel, Ltd.) was added. ”), Granulation was performed at a cylinder temperature of 300 ° C. and a screw rotation speed of 250 rpm to obtain pellets of a thermoplastic resin composition.

<Injection molding 1>
The thermoplastic resin composition pellets obtained by melt kneading 1 were molded by an injection molding machine (“JSW75EII-P” manufactured by Nippon Steel Co., Ltd.) under conditions of a cylinder temperature of 200 to 230 ° C. and a mold temperature of 60 ° C. A test piece for gloss evaluation (length 100 mm, width 100 mm, thickness 2 mm) was obtained.

<Injection molding 2>
The thermoplastic resin composition pellets obtained by melt-kneading 2 were molded by an injection molding machine (“IS55FP-1.5A” manufactured by Toshiba Machine Co., Ltd.) under conditions of a cylinder temperature of 250 to 280 ° C. and a mold temperature of 60 ° C., A test piece for measuring deflection temperature under load, a test piece for measuring Charpy impact strength, and a test piece for measuring tensile elongation were obtained.

<Injection molding 3>
The pellets of the thermoplastic resin composition obtained by melt-kneading 1 were molded by an injection molding machine (“J85AD-110H” manufactured by Nippon Steel Co., Ltd.) under conditions of a cylinder temperature of 280 to 300 ° C. and a mold temperature of 80 ° C. A test piece for combustion test (length 127 mm, width 12.7 mm, thickness 1.5 mm) was obtained.

<Measurement and evaluation results>
The melt volume rate was measured using pellets of the thermoplastic resin composition obtained in the melt kneading 1.
Further, the surface gloss was measured using a test piece obtained by injection molding 1.
Moreover, Charpy impact strength, deflection temperature under load, and tensile elongation were measured using the test piece obtained by injection molding 2.
Furthermore, the combustion test was implemented using the test piece obtained by injection molding 2, and it determined.
The evaluation results are shown in Tables 1 and 2.

From Table 1, in Examples 1-4 which mix | blended the graft copolymer (B-1) of this invention, it turns out that both the fluidity | liquidity and the surface gloss of the molded article obtained are favorable.
On the other hand, in Comparative Examples 1 to 3 in which the graft copolymer (B-2) is blended, it is difficult to achieve both surface gloss and fluidity, and particularly the surface gloss is inferior.

From Table 2, it turns out that in Examples 5-9 which mix | blended the graft copolymer (B-1) of this invention, it is excellent in the balance of impact resistance, heat resistance, and tensile elongation.
On the other hand, in Comparative Examples 4 to 5 in which HIPS is blended, it is difficult to achieve both impact resistance and heat resistance, and in order to improve impact resistance, it is necessary to blend a large amount of HIPS, resulting in a decrease in heat resistance. Concerned. Moreover, about the combustibility, although the combustion rank of the comparative example 4 was V-0, dripping of the melt was seen during the combustion test. Although there was no ignition to the cotton, the combustion behavior was close to V-2 when compared with the combustion modes of other examples and comparative examples.

Claims (11)

  A graft copolymer (B) obtained by graft copolymerizing an aromatic vinyl monomer in the presence of an olefin rubber-like polymer (A) having an average particle size of 0.1 to 1.0 μm, A graft copolymer (B) having a 5% weight loss temperature of 300 ° C or higher.   The number average molecular weight (Mn) in terms of standard polystyrene measured by gel permeation chromatography (GPC) of the acetone-soluble component of the graft copolymer (B) is 10,000 to 100,000. The graft copolymer (B) described in 1.   The graft copolymer (B) according to claim 1 or 2, wherein the olefin rubber-like polymer (A) comprises an ethylene / α-olefin copolymer and / or an ethylene / α-olefin / non-conjugated diene copolymer. ).   In the presence of 10 to 90 parts by mass of the olefinic rubbery polymer (A), 90 to 10 parts by mass of an aromatic vinyl monomer is graft-copolymerized (provided that the olefinic rubbery polymer (A) and The graft copolymer (B) according to any one of claims 1 to 3, wherein the total amount is 100 parts by mass with the aromatic vinyl monomer.   The graft copolymer according to any one of claims 1 to 4, wherein the monomer component graft-copolymerized to the olefin rubber-like polymer (A) is substantially only an aromatic vinyl monomer. (B).   The graft copolymer (B) according to any one of claims 1 to 5, which is an improving agent for a thermoplastic resin (C) containing polystyrene and / or polyphenylene ether.   The graft copolymer (B) according to claim 6, wherein the thermoplastic resin (C) comprises polystyrene and / or polyphenylene ether and a hydrogenated styrene-based thermoplastic elastomer (D).   A thermoplastic resin composition comprising the graft copolymer (B) according to any one of claims 1 to 7 and a thermoplastic resin (C) containing polystyrene and / or polyphenylene ether.   Including 50 to 99.9 parts by mass of thermoplastic resin (C) with respect to 0.1 to 50 parts by mass of graft copolymer (B) (however, graft copolymer (B) and thermoplastic resin (C) And 100 parts by mass in total), the thermoplastic resin composition according to claim 8.   The thermoplastic resin composition according to claim 8 or 9, wherein the thermoplastic resin (C) comprises polystyrene and / or polyphenylene ether and a hydrogenated styrene-based thermoplastic elastomer (D).   A molded article comprising the thermoplastic resin composition according to any one of claims 8 to 10.