JP2020063393A - Heat-resistant styrenic resin composition, non-foam extrusion sheet, foam extrusion sheet and molding - Google Patents

Abstract

To provide a heat-resistant styrenic resin composition excellent in heat resistance, mechanical strength, appearance, and recycle property, and a non-foam and foam extrusion sheet and a molding formed using the heat-resistant styrenic resin composition.SOLUTION: There are provided a heat-resistant styrenic resin composition which contains a predetermined amount of a copolymer resin (a) containing a styrenic monomer unit, an unsaturated carboxylic acid-based monomer unit and an unsaturated carboxylic ester-based monomer unit, a predetermined amount of a rubber-modified styrenic resin (b) and a predetermined amount of a maleic acid anhydride modified ethylene-α-olefin copolymer (c), in which the copolymer resin (a) contains a styrene monomer unit, a methacrylic acid monomer unit and a methyl methacrylate monomer unit with predetermined ratios, and the rubber-modified styrenic resin (b) contains predetermined rubber content and rubber particle diameter; and a non-foam and foam extrusion sheet and a molding formed from the resin composition.SELECTED DRAWING: None

Description

The present invention relates to a heat-resistant styrene resin composition, a non-foamed extruded sheet, a foamed extruded sheet and a molded article.

  A styrene-based resin composition containing a styrene-methacrylic acid-based resin has excellent heat resistance and is relatively inexpensive, and therefore, food containers such as bento and prepared foods, packaging materials, foam boards for heat insulating materials in houses, and diffusing agents. It has been widely used as a diffusing plate of a liquid crystal television containing a styrene, and conventionally, styrene resin compositions containing various styrene-methacrylic acid resins have been proposed (for example, Patent Documents 1 to 3).

Japanese Unexamined Patent Publication No. 02-58548 JP 2012-207201 A JP, 2014-169391, A

Here, in recent years, in order to popularize microwave ovens used for business such as convenience stores, and to shorten the use time of microwave ovens, devices with higher output (in a short time, the temperature easily becomes higher) are being used. There is. Therefore, in the styrene-based resin composition, a resin composition having higher heat resistance is desired.
Further, it is also desired to improve mechanical strength such as brittleness in food containers such as bento and prepared foods because of complicated shapes due to design and increase in size of containers due to increase in contents.
Further, in the case of a product manufactured using a styrene-based resin composition, for example, a foamed product, a film composed of styrene, polypropylene or the like may be laminated on the surface of the product and used as a scrap material. In such recycling, mixing of other resins such as the film may cause deterioration of the physical properties of the resin composition after recycling, and improvement of recyclability of the styrene resin composition is desired.
Further, since the sheet obtained from the styrene resin composition is used for food containers, packaging materials and the like as described above, it is also required that the sheet has a good appearance. However, for example, when the content of methacrylic acid in the resin is generally increased in order to improve the heat resistance of a resin composition containing a styrene-methacrylic acid-based resin, a gelled product due to methacrylic acid is likely to be generated, and the sheet surface In some cases, a poor appearance can be seen, and it is also desired to obtain a good appearance.
That is, the conventional styrene-based resin composition containing a styrene-methacrylic acid-based resin is not sufficient in heat resistance, mechanical strength, appearance, and recyclability, and a resin composition excellent in them is required.

  Under such circumstances, the problems to be solved by the present invention include heat-resistant styrene-based resin composition excellent in heat resistance, mechanical strength, appearance and recyclability, and non-heat-resistant styrene-based resin composition formed using the heat-resistant styrene-based resin composition. It is intended to provide a foam and an extruded sheet of foam, and a molded article molded using the sheet.

The present inventors, in view of the above problems, as a result of intensive studies and experiments, as a result, conventional styrene-based monomer units, unsaturated carboxylic acid-based monomer units, and unsaturated carboxylic acid ester-based monomers By using a resin composition in which a copolymer resin containing units, a specific rubber-modified styrene-based resin, and a maleic anhydride-modified ethylene-α-olefin copolymer are mixed in a specific ratio, the above problems can be solved. The inventors have found that the above can be solved and completed the present invention.
That is, the present invention is as follows.

[1] A copolymer resin (a) containing a styrene-based monomer unit, an unsaturated carboxylic acid-based monomer unit, and an unsaturated carboxylic acid ester-based monomer unit, a rubber-modified styrene-based resin (b), And a heat-resistant styrene-based resin composition containing a maleic anhydride-modified ethylene-α-olefin copolymer (c),
When the total mass of the copolymer resin (a), the rubber-modified styrene resin (b), and the maleic anhydride-modified ethylene-α-olefin copolymer (c) is 100% by mass, the copolymer resin The content of (a) is 60 to 94% by mass, the content of the rubber modified styrene resin (b) is 5 to 30% by mass, and the maleic anhydride modified ethylene-α-olefin copolymer (c) is contained. Content is 1-10 mass%, The heat-resistant styrene resin composition characterized by the above-mentioned.
[2] The total content of the styrene-based monomer unit, the unsaturated carboxylic acid-based monomer unit, and the unsaturated carboxylic acid ester-based monomer unit in the copolymer resin (a) is 100% by mass. At this time, the styrene-based monomer unit is contained in an amount of 69 to 96% by mass, the unsaturated carboxylic acid-based monomer unit is included in an amount of 4 to 16% by mass, and the unsaturated carboxylic acid ester-based unit amount is contained. Containing 0 to 15% by mass of body units,
The rubber content of the rubber-modified styrene-based resin (b) is 5 to 15 mass% when the content of the rubber-modified styrene-based resin (b) is 100 mass%, and the rubber-modified styrene is The heat-resistant styrene resin composition according to the above [1], wherein the rubber particle diameter of the resin (b) is 0.5 to 5.0 μm.
[3] The heat-resistant styrene resin composition according to the above [1] or [2], wherein the α-olefin of the maleic anhydride-modified ethylene-α-olefin copolymer (c) has 3 to 8 carbon atoms. .
[4] The maleic anhydride grafting ratio of the maleic anhydride-modified ethylene-α-olefin copolymer (c) is 100% based on the content of the maleic anhydride-modified ethylene-α-olefin copolymer (c). The heat-resistant styrene-based resin composition according to any one of the above [1] to [3], which is 0.5 to 1.5 mass% when the mass% is defined.
[5] The heat-resistant styrene-based resin according to any one of the above [1] to [4], wherein the maleic anhydride-modified ethylene-α-olefin copolymer (c) is a maleic anhydride ethylene-octene copolymer. Composition.
[6] The core-shell type graft polymer (d) is further combined with the copolymer resin (a), the rubber-modified styrene resin (b), and the maleic anhydride-modified ethylene-α-olefin copolymer (c). The heat-resistant styrene-based resin composition according to any one of the above [1] to [5], containing 1 to 10 parts by weight when the mass is 100 parts by weight.
[7] A non-foamed extruded sheet formed by using the heat-resistant styrene resin composition according to any one of [1] to [6] above.
[8] A foamed extruded sheet formed by using the heat-resistant styrene resin composition according to any one of [1] to [6] above.
[9] A molded product formed using the non-foamed extruded sheet according to [7] above or the foamed extruded sheet according to [8] above.

  According to the present invention, a heat-resistant styrene-based resin composition having excellent heat resistance, mechanical strength, appearance, and recyclability, a non-foamed and foamed extruded sheet formed using the heat-resistant styrene-based resin composition, and A molded article molded using the sheet can be provided.

  Hereinafter, an embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail, but the present invention is not limited to the present embodiment.

[Heat-resistant styrene resin composition]
The heat-resistant styrene resin composition of the present embodiment is a copolymer resin (a) containing a styrene monomer unit, an unsaturated carboxylic acid monomer unit, and an unsaturated carboxylic acid ester monomer unit. A rubber-modified styrene resin (b) and a maleic anhydride-modified ethylene-α-olefin copolymer (c) are contained, and a copolymer resin (a), a rubber-modified styrene resin (b), and maleic anhydride are contained. When the total mass of the modified ethylene-α-olefin copolymer (c) is 100% by mass, the content of the copolymer resin (a) is 60 to 94% by mass, and the content of the rubber modified styrene resin (b) is Is 5 to 30% by mass, and the content of the maleic anhydride-modified ethylene-α-olefin copolymer (c) is 1 to 10% by mass. Hereinafter, the heat-resistant styrene resin composition is also referred to as a resin composition, and the maleic anhydride-modified ethylene-α-olefin copolymer (c) is also referred to as a copolymer (c).

<Copolymer resin (a)>
In the present embodiment, the content of the copolymer resin (a) containing the styrene monomer unit, the unsaturated carboxylic acid monomer unit, and the unsaturated carboxylic acid ester monomer unit is the copolymer resin. When the total mass of (a), the rubber-modified styrene resin (b), and the copolymer (c) is 100 mass%, it is 60 to 94 mass%, preferably 70 to 90 mass%, more preferably 70. Is about 85% by mass. When the content is 60% by mass or more, heat resistance can be improved. On the other hand, by setting the content to 94% by mass or less, the total content of the rubber-modified styrene resin (b) and the copolymer (c) can be secured, and the mechanical strength and the like can be improved. it can.

  In the copolymer resin (a), when the total content of the styrene-based monomer unit, the unsaturated carboxylic acid-based monomer unit, and the unsaturated carboxylic acid ester-based monomer unit is 100% by mass, The content of the styrene-based monomer unit is preferably 69 to 96% by mass, more preferably 74 to 92% by mass, and further preferably 77 to 87% by mass. By setting the content to 69% by mass or more, the fluidity of the resin can be improved. On the other hand, by setting the content to 96% by mass or less, the unsaturated carboxylic acid-based monomer unit described below can be used. Also, it becomes difficult to allow a desired amount of unsaturated carboxylic acid ester-based monomer units to exist, and it becomes difficult to obtain the effects described below due to these monomer units.

  In the resin composition of this embodiment, the unsaturated carboxylic acid monomer unit plays a role of improving heat resistance. When the total content of the styrene monomer unit, the unsaturated carboxylic acid monomer unit, and the unsaturated carboxylic acid ester monomer unit of the copolymer resin (a) is 100% by mass, the unsaturated carboxylic acid The content of the acid-based monomer unit is preferably 4 to 16% by mass, more preferably 6 to 14% by mass, and further preferably 8 to 13% by mass. By setting the content to 4% by mass or more, heat resistance can be further improved. On the other hand, by setting the content to 16% by mass or less, generation of a gelled product in the resin is suppressed, and appearance And the fluidity and mechanical properties of the resin can be improved.

  Generally, a styrene-methacrylic acid-based resin including a styrene-methacrylic acid-methyl methacrylate copolymer resin is produced by radical polymerization in most cases on an industrial scale, but suppresses the gelation reaction in the devolatilization step. Therefore, various alcohols may be added to the polymerization system to carry out the polymerization.

In the present embodiment, the unsaturated carboxylic acid ester monomer is for suppressing the dehydration reaction of the unsaturated carboxylic acid monomer by intermolecular interaction with the unsaturated carboxylic acid monomer, and, It can be used to improve the mechanical strength of the resin. Further, the unsaturated carboxylic acid ester-based monomer also contributes to improvement of resin properties such as weather resistance and surface hardness.
When the total content of the styrene-based monomer unit, the unsaturated carboxylic acid-based monomer unit, and the unsaturated carboxylic acid ester-based monomer unit is 100% by mass, the unsaturated carboxylic acid ester-based monomer unit Is preferably 0 to 15% by mass, more preferably 1 to 12% by mass, and further 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. Further, by setting the content of the unsaturated carboxylic acid ester-based monomer unit to 0% by mass, heat resistance can be improved and cost can be reduced. The content of the body unit may be more than 0% by mass.

  When the unsaturated carboxylic acid-based monomer and the unsaturated carboxylic acid ester-based monomer unit are bonded side by side, a devolatilizer at high temperature and high vacuum is used, and a dealcoholization reaction occurs depending on the conditions. A 6-membered cyclic anhydride may be formed. The copolymer resin (a) of the present embodiment may contain this six-membered cyclic acid anhydride, but the smaller amount is preferable because it lowers the fluidity.

In the present embodiment, the contents of the styrene monomer unit, the methacrylic acid monomer unit and the methyl methacrylate monomer unit in the copolymer resin (a) are respectively determined by proton nuclear magnetic resonance ( ¹ H-NMR ) It can be obtained from the integral ratio of the spectrum measured by the measuring instrument. Also, the content of each monomer unit in the copolymer resin (c) described later can be similarly determined by proton nuclear magnetic resonance measurement.

  In the present embodiment, the copolymer resin (a) comprises a monomer unit other than a styrene monomer unit, an unsaturated carboxylic acid monomer unit, and an unsaturated carboxylic acid ester monomer unit. Although it is not excluded that it is further contained within a range that does not impair the effects of the invention, it is typically a styrene-based monomer unit, an unsaturated carboxylic acid-based monomer unit, and an unsaturated carboxylic acid ester-based monomer unit. Consists of.

  Here, the styrene-based monomer is not particularly limited, and examples thereof include styrene, α-methylstyrene, α-methyl-p-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene. , Ethylstyrene, isobutylstyrene, t-butylstyrene, bromostyrene, chlorostyrene, and indene. From the industrial viewpoint, styrene is preferable as the styrene-based monomer. These styrene-based monomers can be used alone or in combination of two or more.

  The unsaturated carboxylic acid-based monomer is not particularly limited, but examples thereof include methacrylic acid, acrylic acid, maleic anhydride, maleic acid, fumaric acid, and itaconic acid. As the unsaturated carboxylic acid-based monomer, methacrylic acid is preferable because it has a large effect of improving heat resistance, is liquid at room temperature and is excellent in handleability. These unsaturated carboxylic acid monomers can be used alone or in combination of two or more.

  Furthermore, the unsaturated carboxylic acid ester-based monomer is not particularly limited, and examples thereof include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, (meth ) Cyclohexyl acrylate and the like can be mentioned. As the (meth) acrylic acid ester-based monomer, methyl (meth) acrylate is preferable because it has little influence on the decrease in heat resistance. These unsaturated carboxylic acid ester monomers can be used alone or in combination of two or more.

  In the present embodiment, the weight average molecular weight (Mw) of the copolymer resin (a) is preferably 100,000 to 350,000, more preferably 120,000 to 300,000, and further preferably 140,000 to. 240,000. When the weight average molecular weight (Mw) is 100,000 to 350,000, a resin excellent in balance between mechanical strength and fluidity can be obtained, and gel content is small. The weight average molecular weight (Mw) is a value obtained by gel permeation chromatography in terms of standard polystyrene.

  In the present embodiment, the melt flow rate of the copolymer resin (a) is preferably 0.3 to 3.0 g / 10 min, more preferably 0.4 to 2.5 g / 10 min, and further preferably It is 0.4 to 2.0 g / 10 min. The melt flow rate of 0.3 g / 10 min or more is preferable from the viewpoint of fluidity, and the melt flow rate of 3.0 g / 10 min or less is preferable from the viewpoint of mechanical strength of the resin. The melt flow rate is a value measured at 200 ° C. and a load of 49 N according to ISO 1133.

In the present embodiment, the method for polymerizing the copolymer resin (a) is not particularly limited, but for example, a bulk polymerization method or a solution polymerization method can be preferably adopted as the radical polymerization method. The polymerization method mainly includes a polymerization step of polymerizing a polymerization raw material (monomer component) and a devolatilization step of removing volatile components such as unreacted monomers and a polymerization solvent from a polymerization product.
Hereinafter, the method for polymerizing the copolymer resin (a) that can be used in this embodiment will be described.

  When polymerizing the polymerization raw material to obtain the copolymer resin (a), the polymerization raw material composition typically contains a polymerization initiator and a chain transfer agent. As the polymerization initiator, organic peroxides such as 2,2-bis (t-butylperoxy) butane, 1,1-bis (t-butylperoxy) cyclohexane, n-butyl-4,4-bis (t -Butyl peroxy) valerate and other peroxy ketals, di-t-butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide and other dialkyl peroxides, acetyl peroxide, isobutyryl peroxide and other diacyl peroxides, diisopropyl peroxy diester Examples thereof include peroxydicarbonates such as carbonates, peroxyesters such as t-butylperoxyacetate, ketone peroxides such as acetylacetone peroxide, and hydroperoxides such as t-butylhydroperoxide. Among them, 1,1-bis (t-butylperoxy) cyclohexane is preferable from the viewpoint of the decomposition rate and the polymerization rate.

  Examples of the chain transfer agent include α-methylstyrene linear dimer, n-dodecyl mercaptan, t-dodecyl mercaptan, and n-octyl mercaptan.

  As the polymerization method, solution polymerization using a polymerization solvent can be adopted as necessary. Examples of the polymerization solvent used include aromatic hydrocarbons such as ethylbenzene and dialkylketones such as methylethylketone, which may be used alone or in combination of two or more kinds. Other polymerization solvents such as aliphatic hydrocarbons can be further mixed with aromatic hydrocarbons as long as the solubility of the polymerization product is not reduced. It is preferable to use these polymerization solvents in an amount not exceeding 25 parts by mass with respect to 100 parts by mass of all the monomers. If the amount of the polymerization solvent exceeds 25 parts by mass with respect to 100 parts by mass of all the monomers, the polymerization rate tends to be remarkably reduced, and the mechanical strength of the obtained resin tends to be significantly decreased. It is preferable to add 5 to 20 parts by mass with respect to 100 parts by mass of all the monomers before the polymerization, because the quality is easily homogenized and the polymerization temperature is controlled.

  In the present embodiment, the device used in the polymerization step for obtaining the copolymer resin (a) is not particularly limited and may be appropriately selected according to the polymerization method of the styrene resin. For example, in the case of bulk polymerization, it is possible to use a polymerization apparatus in which one or more complete mixing reactors are connected. The devolatilization step is also not particularly limited, and when the bulk polymerization is carried out, the polymerization is advanced until finally the unreacted monomer becomes preferably 50% by mass or less, more preferably 40% by mass or less, and the unreacted monomer is not reacted. In order to remove the volatile components such as the above, devolatilization is performed by a known method. For example, a normal devolatilizing device such as a flash drum, a twin-screw devolatilizer, a thin-film evaporator, an extruder, or the like can be used, but a devolatilizing device with a small retention portion is preferable. The temperature of the devolatilization treatment is usually about 190 to 280 ° C, and more preferably 190 to 260 ° C from the viewpoint of suppressing the formation of a 6-membered cyclic acid anhydride due to the adjacency of methacrylic acid and methyl methacrylate. . The pressure for the devolatilization treatment is usually about 0.13 to 4.0 kPa, preferably 0.13 to 3.0 kPa, and more preferably 0.13 to 2.0 kPa. As the devolatilization method, for example, a method of removing volatile matter by depressurizing it under heating, and a method of removing it through an extruder or the like designed for the purpose of removing volatile matter are desirable.

<Rubber-modified styrene resin (b)>
The rubber-modified styrenic resin (b) in this embodiment is obtained by dispersing particles of the rubber-like polymer in a matrix of the styrene-based resin and polymerizing the styrene-based monomer in the presence of the rubber-like polymer. It can be manufactured. The content of the rubber-modified styrene-based resin (b) is 5 to 30 mass based on 100 mass% of the total mass of the copolymer resin (a), the rubber-modified styrene-based resin (b), and the copolymer (c). %, Preferably 8 to 20% by mass, more preferably 10 to 15% by mass. By setting the content of the rubber-modified styrene resin (b) to 5% by mass or more, the mechanical strength can be improved. On the other hand, if the content is too large, the content of butadiene becomes large, and when the resin composition is foamed, it becomes difficult to foam due to gas escape and the like, but by setting the content to 30% by mass or less, it is preferable. The foam can be foamed, and the physical properties of the resulting foam can be improved. Further, it is possible to improve the rigidity of the obtained molded article and the appearance of a sheet or the like (in the case of a foamed extruded sheet, foaming is likely to break and the appearance may be deteriorated, but this can be avoided. ).

  Examples of the styrene-based monomer that constitutes the styrene-based resin of the rubber-modified styrene-based resin (b) include styrene, α-methylstyrene, α-methyl-p-methylstyrene, o-methylstyrene, and m-methyl. Styrene, p-methylstyrene, vinyltoluene, ethylstyrene, isobutylstyrene, and t-butylstyrene or styrene derivatives such as bromostyrene, chlorostyrene, and indene. Particularly, styrene is preferable from the industrial viewpoint. These styrene-based monomers may be used alone or in combination of two or more. The styrene-based resin does not exclude the inclusion of 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 comprises styrene-based monomer units.

  As the rubber-like polymer of the rubber-modified styrene resin (b), polybutadiene, polyisoprene, natural rubber, polychloroprene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer and the like can be used, but from an industrial viewpoint Polybutadiene and styrene-butadiene copolymers are preferred. As the polybutadiene, both high cis polybutadiene having a high cis content and low cis polybutadiene having a low cis content can be used. As the structure of the styrene-butadiene copolymer, both a random structure and a block structure can be used. These rubber-like polymers may be used alone or in combination of two or more. It is also possible to use a saturated rubber obtained by hydrogenating a butadiene rubber.

  The rubber content contained in the rubber-modified polystyrene-based resin (b) is preferably 5 to 15% by mass, and more preferably 7-14 to 14% by mass, when the rubber-modified polystyrene-based resin (b) is 100% by mass. . By setting the rubber content to 5% by mass or more, it is possible to prevent the mechanical strength from decreasing in the blending with the copolymer resin (a), and to increase the blending ratio of the rubber-modified polystyrene resin (b). The mechanical strength can be improved and the heat resistance can be prevented from being greatly reduced. On the other hand, by setting the rubber content to 15% by mass or less, it is possible to prevent the viscosity of the polymerization system from becoming too high when producing the rubber-modified polystyrene-based resin (b), and to prevent the operation from becoming difficult, and to reduce the rubber particle diameter. Can be easily miniaturized. Furthermore, when blending the copolymer resin (a) and the copolymer resin (c) with the rubber-modified polystyrene-based resin (b), deterioration of mechanical strength or poor appearance of the product due to poor dispersion of the rubber component is prevented. it can. The rubber content is measured by the procedure described in the Examples section or a method understood by one skilled in the art to be equivalent thereto.

  The rubber component in the rubber-modified polystyrene-based resin (b) can be present as rubber particles in the resin composition. In this case, the rubber particle diameter is preferably 0.5 to 5.0 μm, more preferably 0.7 to 4.0 μm, and further preferably 1.0 to 3.0 μm. When the rubber particle size is 0.5 μm or more, the mechanical strength of the resin composition can be improved. Further, by setting the rubber particle diameter to 5.0 μm or less, the appearance of the resin composition can be improved. The rubber-modified polystyrene-based resin (b) is obtained by polymerizing a styrene-based monomer in the presence of a rubber-like polymer in a reactor equipped with a stirrer, and the rubber particle size is the number of revolutions of the stirrer, The molecular weight of the rubber-like polymer used can be adjusted. In the present disclosure, the rubber particle diameter is a value measured from a cross-sectional observation image by a transmission electron microscope.

  The melt flow rate of the rubber-modified polystyrene-based resin (b) at 200 ° C. is preferably 0.5 to 20.0 g / 10 min, more preferably 1.0 to 18.0 g / 10 min, and further preferably 1.0 to. It is 16.0 g / 10 min. When the melt flow rate is in the range of 0.5 to 20.0 g / 10 min, the miscibility with the copolymer resin (a) and the copolymer resin (c) is good, and the mechanical strength is also good. In the present disclosure, the melt flow rate is a value measured at 200 ° C. and a load of 49 N according to ISO 1133.

  The method for producing the rubber-modified styrenic resin (b) is not particularly limited, but for example, bulk polymerization (or solution polymerization) of polymerizing a styrenic monomer (and solvent) in the presence of a rubbery polymer, or reaction It can be produced by bulk-suspension polymerization which shifts to suspension polymerization on the way, or by emulsion graft polymerization in which a styrene monomer is polymerized in the presence of a rubbery polymer latex. In the bulk polymerization, a rubber-like polymer, a styrene-based monomer, and, if necessary, a mixed solution containing an organic solvent, an organic peroxide, and / or a chain transfer agent is added to a complete mixing type reactor or a tank type. It can be produced by continuously supplying a reactor and a polymerization apparatus configured by connecting a plurality of tank reactors in series.

  In the present embodiment, the swelling index of the toluene-insoluble matter in the rubber-modified styrene resin (b) is 8.0 to 14.0, and the ratio of the mass of the toluene-insoluble matter to the rubber content in the toluene-insoluble matter (toluene). The mass of insoluble matter / rubber content in toluene insoluble matter) is preferably from 1.5 to 4.0. The swelling index is more preferably 9.0 to 13.0, further preferably 9.5 to 12.5. The ratio of mass of toluene insoluble matter / rubber content in toluene insoluble matter is more preferably 2.0 to 3.5, further preferably 2.5 to 3.5. The swelling index of the toluene insoluble matter of the rubber-modified styrene resin (b) is 8.0 to 14.0, and the ratio of the mass of the toluene insoluble matter / the rubber content in the toluene insoluble matter is 1.5 to 4. When it is 0, a resin having excellent mechanical strength is obtained. In the present disclosure, the swelling index of the toluene insoluble matter and the ratio of the mass of the toluene insoluble matter / the rubber content in the toluene insoluble matter are the same as those described in the Examples section or equivalent thereto. It is a value measured by a procedure that is understood.

<Maleic anhydride-modified ethylene-α-olefin copolymer (c)>
In the present embodiment, the heat-resistant styrene resin composition contains a maleic anhydride-modified ethylene-α-olefin copolymer (c). The maleic anhydride-modified ethylene-α-olefin copolymer (c) is obtained by graft-modifying an ethylene-α-olefin copolymer with maleic anhydride.
In the copolymer (c), the maleic anhydride portion in the copolymer (c) is easily compatible with the copolymer resin (a), and the ethylene-α-olefin portion in the copolymer (c) is rubber-modified. Since it is easily compatible with the styrene resin (b), the copolymer (c) can act as a compatibilizing agent for the copolymer resin (a) and the rubber-modified styrene resin (b). Therefore, the copolymer resin (a) and the rubber-modified styrene-based resin (b) are prevented from being separated from each other, so that impact strength and appearance can be improved. Moreover, since the maleic anhydride portion in the copolymer (c) interacts with the methacrylic acid portion of the copolymer resin (a), gelation of the copolymer resin (a) can be suppressed and the appearance can be improved. it can. Furthermore, since the copolymer (c) has an ethylene-α-olefin moiety that is hardly compatible with the copolymer resin (a), the heat resistance of the copolymer resin (a) having heat resistance is less likely to be affected, The heat resistance of the entire composition can be secured. Then, the presence of the copolymer (c) can improve the recyclability.

  In the present embodiment, the content of the maleic anhydride-modified ethylene-α-olefin copolymer (c) is the total of the copolymer resin (a), the rubber-modified styrene resin (b), and the copolymer (c). The amount is 1 to 10% by mass, preferably 1.5 to 8% by mass, and more preferably 2 to 6% by mass, relative to 100% by mass.

  When the content is 1% by mass or more, impact strength and appearance can be improved. On the other hand, when the content is 10% by mass or less, the rigidity can be improved. Further, if the content is too large, the copolymer (c) in the resin composition tends to be present in a large amount in the surface layer, and the heat resistance in the surface layer may be easily decreased, or the surface layer may be peeled off. However, if the content is 10 mass% or less, the heat resistance and the appearance will not be deteriorated.

  The maleic anhydride-modified ethylene-α-olefin copolymer (c) is a styrene-methacrylic acid-methyl methacrylate copolymer having a dispersibility of the rubber-modified styrene resin (b) in the copolymer resin (a). It is possible to control and improve impact resistance without significantly lowering heat resistance. Further, it is also effective in preventing gelation of the styrene-methacrylic acid-methyl methacrylate copolymer (a), and is effective in improving the appearance and moldability. From the viewpoints of heat resistance, impact resistance, appearance, and moldability, the maleic anhydride-modified ethylene-α-olefin copolymer (c) has a maleic anhydride grafting ratio of maleic anhydride-modified ethylene-α-olefin. When the content of the copolymer (c) is 100% by mass, it is preferably 0.5 to 1.5% by mass.

  The ethylene-α-olefin copolymer of the maleic anhydride-modified ethylene-α-olefin copolymer (c) is not particularly limited, but for example, ethylene and a carbon number of 3 to 20, more preferably a carbon number of An ethylene-α-olefin copolymer rubber composed of 6 to 12 α-olefins can be mentioned. Examples of the α-olefin having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-. Dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 3-methyl-1-butene, 4-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1- Pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 9-methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1-tetrade Emissions and combinations thereof. Among them, hexene, 4-methylpentene and octene are preferable, and octene-1 is particularly preferable. These are more preferably produced by a known metallocene catalyst or Ziegler catalyst, and most preferably produced by a metallocene catalyst. Further, 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,4-octadiene, 1,5-octadiene, 1,6-octadiene, 1,7-octadiene, 2-methyl-1, 5-hexadiene, 6-methyl-1,5-heptadiene, 7-methyl-1,6-octadiene, 4-ethylidene-8-methyl-1,7-nonadiene, 4,8-dimethyl-1,4,8- Decatriene (DMDT), dicyclopentadiene, cyclohexadiene, dicyclooctadiene, methylenenorbornene, 5-vinylnorbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-norbornene, 6-chloromethyl-5-isopropylen-2-norbornene, 2,3-diisopropylidene- - norbornene, 2-ethylidene-3-isopropylidene-5-norbornene may be copolymerized non-conjugated diene polyene such as 2-propenyl-2,2-norbornadiene.

  In the present embodiment, the method for producing the maleic anhydride-modified ethylene-α-olefin copolymer (c) is not particularly limited, and a known method can be used. For example, an ethylene-α-olefin copolymer is used. A melt modification method in which maleic anhydride as a graft monomer is melted and graft-copolymerized, or a solution modification method in which it is dissolved in a solvent and a graft monomer is added and graft-copolymerized can be used.

<Core-shell type graft polymer (d)>
In the present embodiment, the heat-resistant styrene resin composition can contain the core-shell type graft polymer (d). The content of the core-shell type graft polymer (d) is 10 parts by mass or less when the total mass of the copolymer resin (a), the rubber-modified styrene resin (b), and the copolymer (c) is 100 parts by mass. Is preferable, more preferably 8 parts by mass or less, further preferably 6 parts by mass or less. When the resin composition contains the core-shell type graft polymer (d), the mechanical strength of the resin composition can be improved, but when the content is 10 parts by mass or less, gas is released during foam molding. For example, it is possible to prevent foaming from becoming difficult and to prevent deterioration of physical properties of the obtained foam. Further, it is possible to prevent the rigidity of the obtained molded product from being lowered. On the other hand, the content is preferably 1 part by mass or more, and more preferably 2 parts by mass or more, from the viewpoint of satisfactorily obtaining the effect of improving mechanical strength.

  The core-shell type graft polymer (d) is selected from aromatic vinyl, vinyl cyanide, acrylic acid ester, methacrylic acid ester, and vinyl compounds copolymerizable with these, with a rubber component having a glass transition temperature of 10 ° C. or less as a core. It is a graft copolymer obtained by copolymerizing one or more of the above-mentioned monomers as a shell.

  Examples of the rubber component of the core-shell type graft polymer (d) include butadiene rubber, butadiene-acrylic composite rubber, acrylic rubber, acrylic-silicone composite rubber, isobutylene-silicone composite rubber, isoprene rubber, styrene-butadiene rubber, chloroprene rubber, ethylene- Examples thereof include propylene rubber, nitrile rubber, ethylene-acrylic rubber, silicone rubber, epichlorohydrin rubber, fluororubber, and those in which hydrogen is added to the unsaturated bond portion. A rubber component containing no halogen atom is preferable from the viewpoint of suppressing the fear that harmful substances are generated during combustion. The glass transition temperature of the rubber component is preferably −10 ° C. or lower, more preferably −30 ° C. or lower. Particularly preferred as the rubber component are butadiene rubber, butadiene-acrylic composite rubber, acrylic rubber, and acrylic-silicone composite rubber. The composite rubber means a rubber obtained by copolymerizing two kinds of rubber components or a rubber obtained by polymerizing so as to have an IPN structure in which they are intertwined with each other so as not to be separated. In the core-shell type graft polymer (d), the weight average particle diameter of the core is preferably 0.05 to 0.8 μm, more preferably 0.1 to 0.6 μm, and further preferably 0.15 to 0.5 μm. preferable. In the range of 0.05 to 0.8 μm, better impact resistance is achieved.

  In the core-shell type graft polymer (d), examples of the aromatic vinyl in the vinyl compound copolymerized as a shell with the rubber component include styrene, α-methylstyrene, p-methylstyrene, alkoxystyrene, halogenated styrene and the like. You can Examples of the acrylate ester include methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, octyl acrylate and the like. Examples of the methacrylic acid ester include methyl methacrylate, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, octyl methacrylate and the like. Methyl methacrylate is especially preferred. Among these, it is particularly preferable to contain a methacrylic acid ester such as methyl methacrylate as an essential component. From the viewpoint of mechanical properties and thermal stability, it is more preferable not to include an aromatic vinyl component.

  More specifically, the methacrylic acid ester is contained in 100% by weight of the graft component (in the case of a core-shell polymer, 100% by weight of the shell), preferably 10% by weight or more, and more preferably 15% by weight or more. It is preferable. The elastic polymer containing a rubber component having a glass transition temperature of 10 ° C. or lower may be produced by any one of bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization. It may be a one-stage graft or a multi-stage graft. Further, it may be a mixture with a copolymer containing only a graft component produced as a by-product during the production.

  Examples of the polymerization method include a general emulsion polymerization method, a soap-free polymerization method using an initiator such as potassium persulfate, a seed polymerization method, and a two-step swelling polymerization method. Further, in the suspension polymerization method, a method in which an aqueous phase and a monomer phase are separately held and both are accurately supplied to a continuous disperser, and the particle diameter is controlled by the number of revolutions of the disperser, and continuous production In the method, a method of controlling the particle size by supplying the monomer phase through an orifice having a diameter of several to several tens of μm or a porous filter in an aqueous liquid having dispersibility to control the particle size may be performed. In the case of a core-shell type graft polymer, the reaction may be carried out in either one stage or multiple stages for both the core and the shell.

  As such a polymer, a commercially available product may be used, and thus it can be easily obtained. For example, as a rubber component, one containing butadiene rubber as a main component is Kane Ace M series manufactured by Kaneka Corporation (for example, M-711 having a methyl methacrylate as a main component as a shell component, and methyl methacrylate / styrene as a main component as a shell component). M-701), Mitsubishi Rayon Co., Ltd., Metabrene C series (for example, C-223A whose shell component is mainly composed of methyl methacrylate / styrene), E series (for example, shell component is mainly composed of methyl methacrylate / styrene) E-860A) and DOW Chemical Co.'s Paraloid EXL series (for example, EXL-2690 whose shell component is mainly composed of methyl methacrylate).

  Examples of those containing acrylic rubber or butadiene-acrylic composite rubber as a main component include W series (for example, W-600A whose shell component contains methyl methacrylate as a main component) and Paraloid EXL series of DOW Chemical Co. (for example, shell component contains EXL-2390 containing methyl methacrylate as a main component).

  As a rubber component containing an acrylic-silicone composite rubber as a main component, METBRENE S-2001 whose main shell component is methyl methacrylate or SRK whose main shell component is acrylonitrile styrene manufactured by Mitsubishi Rayon Co., Ltd. -200A is mentioned.

<Primary aliphatic alcohol>
In the present embodiment, the heat-resistant styrene-based resin composition has a freezing point of −10 ° C. or lower and an aliphatic primary alcohol having a carbon number of 14 or more as a copolymer resin ( 0.02 to 1.0 part by mass can be contained with respect to 100 parts by mass of a). The addition of the aliphatic primary alcohol is effective for suppressing the gelation reaction due to the dehydration reaction of methacrylic acid, and it is particularly preferable to add the aliphatic primary alcohol to the system during the production of the copolymer resin (a). Is desirable. When the alcohol having a carbon number of less than 14 is used in a high vacuum for the purpose of removing low volatile components such as residual monomers or water during the production of the copolymer resin (a) or the extrusion of the sheet from the resin composition. , Easily volatilizes, and the effect of suppressing the gelation reaction tends to be weakened. Therefore, the larger the carbon number of the aliphatic primary alcohol, the more preferable.

  In the present embodiment, the addition amount of the aliphatic primary alcohol having 14 or more carbon atoms is preferably 0.02 to 1.0 part by mass, more preferably 0.04 to 0. 8 parts by mass, more preferably 0.06 to 0.6 parts by mass. Under the alcohol addition conditions such that the above content is 0.02 parts by mass or more, the gelation reaction is good during the devolatilization step during the production of the copolymer resin (a) or the copolymer resin (c) or during the extrusion of the sheet. Can be suppressed. On the other hand, under the addition conditions such that the content is 1.0 part by mass or less, the gelling reaction can be favorably suppressed, and the residual amount of the aliphatic primary alcohol in the resin composition increases. Not too much, the heat resistance of the resin does not deteriorate, and mold deposits do not easily occur during molding. As the aliphatic primary alcohol having 14 or more carbon atoms, an isotype aliphatic primary alcohol having a freezing point of −10 ° C. or lower is particularly preferable. When the freezing point is −10 ° C. or lower, and when a high vacuum is applied for the purpose of removing low volatile components such as water and residual monomers, the alcohol is less likely to deposit in the condenser and the vacuum degree is less likely to decrease, which is preferable. The content of the aliphatic primary alcohol having 14 or more carbon atoms can be measured by gas chromatography.

  Examples of the aliphatic primary alcohol include n-myristate alcohol, n-palmitate alcohol, n-stearyl alcohol and the like. Further, as the isoaliphatic primary alcohol having a freezing point of −10 ° C. or lower, isotetradecanol having 14 carbon atoms, isohexadecanol having 16 carbon atoms, isooctadecanol having 18 carbon atoms, and isocarbon having 20 carbon atoms are used. Eicosanol is mentioned, for example, specifically, 7-methyl-2- (3-methylbutyl) -1-octanol, 5-methyl-2- (1-methylbutyl) -1-octanol, 5-methyl-. 2- (3-methylbutyl) -1-octanol, 2-hexyl-1-decanol, 5,7,7-trimethyl-2- (1,3,3-trimethylbutyl) -1-octanol, 8-methyl-2 -(4-Methylhexyl) -1-decanol, 2-heptyl-1-undecanol, 2-heptyl-4-methyl-1-decanol, 2- (1,5-dimethylhexyl) - (5,9-dimethyl) -1-decanol, and the like. Among these, isooctadecanol having 18 carbon atoms is particularly preferable from the industrial viewpoint.

<Other additives>
In the present embodiment, in addition to the above components, the heat-resistant styrene-based resin composition may contain known additives, processing aids, and the like, if necessary, within a range that does not impair the effects of the present invention. Examples of these additives and the like include antioxidants, weathering agents, lubricants, antistatic agents, and fillers.

Examples of the antioxidant include phenol-based compounds, phosphorus-based compounds and thioether-based compounds.
Examples of phenolic antioxidants include 2,6-di-tert-butyl-p-cresol, 2,6-diphenyl-4-octadecyloxyphenol, distearyl (3,5-di-tert-butyl-4-). Hydroxybenzyl) phosphonate, 1,6-hexamethylene bis [(3,5-ditertiary butyl-4-hydroxyphenyl) propionic acid amide], 4,4′-thiobis (6-tertiary butyl-m-cresol) 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), 4,4'-butylidenebis (6-tert-butyl-) m-cresol), 2,2'-ethylidene bis (4,6-di-tert-butylphenol), 2,2'-ethylidene bis (4-tert-butyl-6-tert-butylphenol), , 1,3-Tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-Tris (2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl) isocyanate Nulate, 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-Tris (3,5-di-tert-butyl-4-hydroxybenzyl)- 2,4,6-Trimethylbenzene, 2-tert-butyl-4-methyl-6- (2-acryloyloxy-3-tert-butyl-5-methylbenzyl) phenol, stearyl (3,5-ditert-butyl) -4-hydroxyphenyl) propionate, tetrakis [methyl 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, thiodiethylene glycol bis [(3 5-ditertiary butyl-4-hydroxyphenyl) propionate], 1,6-hexamethylene bis [(3,5-ditertiary butyl-4-hydroxyphenyl) propionate], bis [3,3-bis (4 -Hydroxy-3-tert-butylphenyl) butyric acid] glycol ester, bis [2-tert-butyl-4-methyl-6- (2-hydroxy-3-tert-butyl-5-methylbenzyl) phenyl] terephthalate , 1,3,5-Tris [(3,5-ditertiarybutyl-4-hydroxyphenyl) propionyloxyethyl] isocyanurate, 3,9-bis [1,1-dimethyl-2-{(3-tertiary 3-Butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, Examples include polyethylene glycol bis [(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate] and the like. You may use these in mixture of 2 or more types.

  Examples of the phosphorus-based antioxidant include trisnonylphenylphosphite, tris [2-tert-butyl-4- (3-tert-butyl-4-hydroxy-5-methylphenylthio) -5-methylphenyl] phosphite. Fight, tridecyl phosphite, octyl diphenyl phosphite, di (decyl) monophenyl phosphite, di (tridecyl) pentaerythritol diphosphite, di (nonylphenyl) pentaerythritol diphosphite, bis (2,4-di 3-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,4,6-tri-tert-butylphenyl) pentaerythritol diphosphite Fight, bis (2,4-dicumylphenyl) pentae Thritol diphosphite, tetra (tridecyl) isopropylidene diphenol diphosphite, tetra (tridecyl) -4,4'-n-butylidene bis (2-tert-butyl-5-methylphenol) diphosphite, hexa (tridecyl)- 1,1,3-Tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butanetriphosphite, tetrakis (2,4-di-tert-butylphenyl) biphenylenediphosphonite, 9,10-dihydro- 9-oxa-10-phosphaphenanthrene-10-oxide, 2,2'-methylenebis (4,6-tert-butylphenyl) -2-ethylhexylphosphite, 2,2'-methylenebis (4,6-) Tert-Butylphenyl) -octadecyl phosphite, 2,2'-ethylidene bis (4,6 Di-tert-butylphenyl) fluorophosphite, tris (2-[(2,4,8,10-tetrakis-tert-butyldibenzo [d, f] [1,3,2] dioxaphosphepin-6-yl ) Oxy] ethyl) amine, phosphite of 2-ethyl-2-butylpropylene glycol and 2,4,6-tri-tert-butylphenol, and the like. You may use these in mixture of 2 or more types.

  Examples of the thioether antioxidants include dilauryl thiodipropionate, dimyristyl thiodipropionate, dialkylthiodipropionates such as distearyl thiodipropionate, and pentaerythritol tetra (β-alkylmercaptopropionate). These may be used as a mixture of two or more kinds.

As the weather resistance agent, an ultraviolet absorber, a hindered amine light stabilizer, or the like can be used.
Examples of the ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone and 5,5′-methylenebis (2-hydroxy-4-methoxybenzophenone). 2-hydroxybenzophenones such as; 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-ditertiarybutylphenyl) -5-chlorobenzo Triazole, 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-5'-tertiary octyl Phenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-dicumylphenyl) benzotriazole, 2,2'-methylenebis (4- 2- (2'-hydroxyphenyl) benzotriazole such as 3-octyl-6- (benzotriazolyl) phenol) and 2- (2'-hydroxy-3'-tert-butyl-5'-carboxyphenyl) benzotriazole Kinds; Phenyl salicylate, resorcinol monobenzoate, 2,4-ditertiary butylphenyl-3,5-ditertiary butyl-4-hydroxybenzoate, 2,4-ditertiary amylphenyl-3,5-ditertiary Benzoates such as butyl-4-hydroxybenzoate and hexadecyl-3,5-di-tert-butyl-4-hydroxybenzoate; 2-ethyl-2'-ethoxyoxanilide, 2-ethoxy-4'-dodecyloxanilide Substituted oxanilides such as ethyl; α-cyano-β, β-diphenyl acrylate, methyl-2-cyano-3-me Cyanoacrylates such as 3- (p-methoxyphenyl) acrylate; 2- (2-hydroxy-4-octoxyphenyl) -4,6-bis (2,4-ditertiarybutylphenyl) -s- Triazine, 2- (2-hydroxy-4-methoxyphenyl) -4,6-diphenyl-s-triazine, 2- (2-hydroxy-4-propoxy-5-methylphenyl) -4,6-bis (2,2 Examples include triaryltriazines such as 4-ditertiarybutylphenyl) -s-triazine. You may use these in mixture of 2 or more types.

  Examples of the hindered amine light stabilizer include 2,2,6,6-tetramethyl-4-piperidyl stearate, 1,2,2,6,6-pentamethyl-4-piperidyl stearate, 2,2,6. , 6-Tetramethyl-4-piperidyl benzoate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-tetramethyl-4-piperidyl) sebacate , Bis (1-octoxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4- Butanetetracarboxylate, tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, bis (2,2,6 6-Tetramethyl-4-piperidyl) -di (tridecyl) -1,2,3,4-butanetetracarboxylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) -di (tridecyl) ) -1,2,3,4-Butane tetracarboxylate, bis (1,2,2,4,4-pentamethyl-4-piperidyl) -2-butyl-2- (3,5-di-tert-butyl- 4-hydroxybenzyl) malonate, 1- (2-hydroxyethyl) -2,2,6,6-tetramethyl-4-piperidinole / diethyl succinate polycondensate, 1,6-bis (2,2,2) 6,6-Tetramethyl-4-piperidylamino) hexane / 2,4-dichloro-6-morpholino-s-triazine polycondensate, 1,6-bis (2,2,6,6-tetramethyl-4- Piperidylamino) Sun / 2,4-dichloro-6-tertiary octylamino-s-triazine polycondensate, 1,5,8,12-tetrakis [2,4-bis (N-butyl-N- (2,2,6 , 6-Tetramethyl-4-piperidyl) amino) -s-triazin-6-yl] -1,5,8,12-tetraazadodecane, 1,5,8,12-tetrakis [2,4-bis ( N-Butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino) -s-triazin-6-yl] -1,5,8-12-tetraazadodecane, 1,6 , 11-Tris [2,4-bis (N-butyl-N- (2,2,6,6-tetramethyl-4-piperidyl) amino) -s-triazin-6-yl] aminoundecane, 1,6 , 11-Tris [2,4-bis (N-butyl-N- (1,2,2,6 And hindered amine compounds such as 6-pentamethyl-4-piperidyl) amino) -s-triazin-6-yl] aminoundecane. You may use these in mixture of 2 or more types.

  As the lubricant, a fatty acid amide, a fatty acid ester, a fatty acid, a fatty acid metal salt, or the like can be used.

  Examples of the aliphatic amide lubricant include stearic acid amide, oleic acid amide, erucic acid amide, behenic acid amide, ethylenebisstearic acid amide, ethylenebisoleic acid amide, ethylenebiserucic acid amide, and ethylenebislauric acid amide. To be You may use these in mixture of 2 or more types.

  Aliphatic ester lubricants include methyl laurate, methyl myristate, methyl palmitate, methyl stearate, methyl oleate, methyl erucate, methyl behenate, butyl laurate, butyl stearate, isopropyl myristate, palmitic acid. Isopropyl, octyl palmitate, coconut fatty acid octyl ester, octyl stearate, beef tallow fatty acid octyl ester, lauryl laurate, stearyl stearate, behenyl behenate, cetyl myristate, straight chain with 28 to 30 carbon atoms, saturated without branching Monocarboxylic acid (abbreviated as montanic acid) and ethylene glycol ester, montanic acid and glycerin ester, montanic acid and butylene glycol ester, montanic acid and trimethylolethane ester Esters of montanic acid and trimethylolpropane, esters of montanic acid and pentaerythritol, glycerin monostearate, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, sorbitan trioleate, Examples thereof include polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate and polyoxyethylene sorbitan trioleate. You may use these in mixture of 2 or more types.

  As saturated fatty acids among fatty acid-based lubricants, specifically, lauric acid (dodecanoic acid), isodecanoic acid, tridecylic acid, myristic acid (tetradecanoic acid), pentadecyl acid, palmitic acid (hexadecanoic acid), margaric acid (heptadecanoic acid) , Stearic acid (octadecanoic acid), isostearic acid, tuberculostearic acid (nonadecanoic acid), 2-hydroxystearic acid, arachidic acid (icosanoic acid), behenic acid (docosanoic acid), lignoceric acid (tetradocosanoic acid), serotic acid ( Hexadocosanoic acid), montanic acid (octadocosanoic acid), melissic acid, and the like, and particularly lauric acid, palmitic acid, stearic acid, behenic acid, 12-hydroxystearic acid, montanic acid, and the like.

  Among the fatty acid-based lubricants, unsaturated fatty acids include, specifically, myristoleic acid (tetradecenoic acid), palmitoleic acid (hexadecenoic acid), oleic acid (cis-9-octadecenoic acid), and elaidic acid (trans-9-octadecenoic acid). ), Ricinoleic acid (octadecadienoic acid), vaccenic acid (cis-11-octadecenoic acid), linoleic acid (octadecadienoic acid), linolenic acid (9,11,13-octadecatrienoic acid), and estearic acid ( Examples thereof include 9,11,13-octadecatrienoic acid), gadoleic acid (icosanoic acid), erucic acid (docosanoic acid), and nervonic acid (tetradocosanoic acid). You may use these in mixture of 2 or more types.

  Examples of the fatty acid metal salt-based lubricant include lithium salts, calcium salts, magnesium salts and aluminum salts of the fatty acid of the above fatty acid-based lubricant. You may use these in mixture of 2 or more types.

  As the antistatic agent, cationic type, anionic type, nonionic type, amphoteric type, fatty acid partial esters such as glycerin fatty acid monoester, and the like can be used.

  Specifically, alkyltrimethylammonium salt, dialkyldimethylammonium salt, benzalkonium salt, N, N-bis (2-hydroxyethyl) -N- (3-dodecyloxy-2-hydroxypropyl) methylammonium mesosulfate. , (3-laurylamidopropyl) trimethylammonium methyl sulfate, stearoamidopropyldimethyl-2-hydroxyethylammonium nitrate, stearoamidopropyldimethyl-2-hydroxyethylammonium phosphate, cationic polymer, alkylsulfonate , Alkylbenzene sulfonate, sodium alkyl diphenyl ether disulfonate, alkyl nitrate ester salt, phosphoric acid alkyl ester salt, alkyl phosphate amine salt, stearic acid monoglyceride , Pentaerythritol fatty acid ester, sorbitan monopalmitate, sorbitan monostearate, diglycerin fatty acid ester, alkyldiethanolamine, alkyldiethanolamine fatty acid monoester, alkyldiethanolamide, polyoxyethylene dodecyl ether, polyoxyethylene alkylphenyl ether, polyethylene glycol Examples thereof include monolaurate, polyoxyethylene alkylamine, polyoxyethylene alkylamide, polyether block copolymer, cetyl betaine, hydroxyethyl imidazoline sulfate and the like. You may use these in mixture of 2 or more types.

  As the filler, talc, calcium carbonate, barium sulfate, carbon fiber, mica, wollastonite, whiskers and the like can be used.

  In addition, anti-blocking agents, colorants, anti-blooming agents, surface treatment agents, antibacterial agents, and anti-eye candy agents (silicone oils described in JP2009-120717A, monoamide compounds of higher aliphatic carboxylic acids, and higher aliphatic carboxyls). An anti-corrosion agent such as a monoester compound obtained by reacting an acid with a monovalent to trivalent alcohol compound) and the like may be added.

  The additive amount of the additive and the processing aid is usually 0.05 to 5 mass% in the resin composition.

In the present embodiment, as described above, the heat-resistant styrene-based resin composition comprises the core-shell type graft polymer (d), the copolymer resin (a), the rubber-modified styrene-based resin (b), and the copolymer (c). However, it may consist essentially of only components (a) to (d) and any optional components. Moreover, it may consist only of (a) component- (d) component, or (a) component- (d) component and an optional addition component.
The phrase “substantially consisting of the components (a) to (d) and optional additional components” means that 95% by mass or more and 100% by mass or less (preferably 98% by mass or more and 100% by mass) of the composition is (a ) Component to (d) component, or (a) component to (d) component and optional addition component. The composition of the present embodiment may contain unavoidable impurities in addition to the components (a) to (d) and the optional addition component, as long as the effects of the present invention are not impaired.

<Characteristics of heat-resistant styrene resin composition>
The heat-resistant styrene resin composition of the present embodiment has a Vicat softening temperature of preferably 104 ° C. or higher, more preferably 110 ° C. or higher, still more preferably 115 ° C. or higher. When the Vicat softening temperature is 105 ° C. or higher, the heat resistance of the resin composition can be secured. The Vicat softening temperature can be measured in accordance with ISO 306 under the conditions of a load of 50 N and a heating rate of 50 ° C./h.

Charpy impact strength of the heat-resistant styrenic resin composition of the present embodiment (with notch) is preferably 1.3 kJ / ^{m 2} or more, more preferably 1.5 kJ / ^{m 2} or more, more preferably It is 1.8 kJ / m ² or more. When the Charpy impact strength (notched) is 1.3 kJ / m ² or more, the mechanical strength of the resin composition can be secured. The Charpy impact strength (without notch) can be measured according to ISO179.

[Kneading / molding]
In this embodiment, the heat-resistant styrene resin composition can be produced by melt-kneading each component by an arbitrary method. For example, a high-speed stirrer typified by a Henschel mixer, a batch-type kneader typified by a Banbury mixer, a single- or twin-screw continuous kneader, a roll mixer, or the like may be used alone or in combination. The heating temperature at the time of kneading is usually selected in the range of 200 to 260 ° C.

  The heat-resistant styrene resin composition of the present embodiment, the above-mentioned melt-kneading molding machine, or, using the obtained pellets as a raw material, injection molding method, injection compression molding method, extrusion molding method, blow molding method, press molding method, For example, a molded product as described below can be obtained by a vacuum molding method, a foam molding method, or the like.

[Non-foamed and foamed extruded sheets]
The non-foamed extruded sheet and the foamed extruded sheet of the present embodiment are formed using the heat-resistant styrene resin composition of the above-described embodiment of the present invention. As a method for producing the non-foamed and foamed extruded sheet, a generally known method can be used.
Examples of the method for producing the non-foamed extruded sheet include a method of using a short axis or biaxial extrusion molding machine equipped with a T die and a device for pulling the sheet with a uniaxial stretching machine or a biaxial stretching machine. Examples of the method for producing the sheet include a method using an extrusion foam molding machine equipped with a T die or a circular die.

  In the foamed extruded sheet, substances usually used can be used as the foaming agent and the foam nucleating agent at the time of extrusion foaming. As the foaming agent, butane, pentane, freon, carbon dioxide, water and the like can be used, butane is preferred. Further, talc or the like can be used as the foam nucleating agent.

In the foamed extruded sheet, the thickness is preferably 0.5 mm to 5.0 mm, the apparent density is preferably 50 g / L to 300 g / L, and the basis weight is 80 g / m ^{2 to} 300 g / m. It is preferably ² . In addition, the foamed extruded sheet is not particularly limited, but is layered with, for example, a styrene-based resin (polystyrene resin, styrene-butadiene block copolymer, high-impact polystyrene (rubber-resistant polystyrene) composed of a rubber component such as polybutadiene). It may be used, or in addition to it, or in place of it, it may be used as a multilayer with a resin other than the styrene resin. The resin other than the styrene resin is not particularly limited, but examples thereof include polypropylene (PP) resin, PP / polystyrene (PS) resin, polyethylene terephthalate (PET) resin, and nylon resin.

  On the other hand, the thickness of the non-foamed extruded sheet is preferably about 0.1 to 1.5 mm, from the viewpoint of rigidity and thermoforming cycle. The non-foamed extruded sheet may be formed only by ordinary low-magnification roll stretching, but in particular, a sheet stretched by a roll about 1.3 to 7 times and then stretched by a tenter about 1.3 to 7 times. Is preferable in terms of strength. Further, the non-foamed extruded sheet is not particularly limited, but may be used in a multilayer structure with a styrene resin (polystyrene resin, styrene-butadiene block copolymer or high impact polystyrene composed of a rubber component such as polybutadiene), In addition to that, or in place of it, it may be used as a multilayer with a resin other than the styrene resin. The resin other than the styrene resin is not particularly limited, but examples thereof include PP resin, PP / PS resin, PET resin, nylon resin and the like.

[Molding]
The molded article of this embodiment is formed using the non-foamed extruded sheet or the foamed extruded sheet of the above-described embodiment of the present invention. The foamed extruded sheet (including the multilayered sheet as described above) can be molded by, for example, but not limited to, vacuum molding to form a molded product, for example, a container such as a tray. Although the non-foamed extruded sheet is not particularly limited, it can be formed by vacuum forming, for example, to produce a molded product, for example, a lid material for a bento box or a container for a side dish or the like.

  Using the heat-resistant styrene-based resin composition of the embodiment according to the present invention, non-foamed and foamed extruded plates, extruded sheets, food containers by secondary processing of these, molded articles such as packaging materials, heat resistance, Excellent mechanical strength and appearance. Further, the heat-resistant styrene-based resin composition of the embodiment according to the present invention can be widely used as a raw material of a molded product by injection molding or the like, for various purposes such as electric product parts, toys, sundries, daily necessities and various industrial parts. The role played by the industrial world is great.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

[Properties of Copolymer Resin (a), Rubber Modified Styrene Resin (b), and Resin Composition]
(1) Measurement of content (mass%) of each monomer unit of styrene, methacrylic acid and methyl methacrylate of the copolymer resin (a):
The resin composition was quantified from the integral ratio of the spectrum measured by a proton nuclear magnetic resonance ( ¹ H-NMR) measuring machine.
Sample preparation: 30 mg of resin pellets were dissolved in 0.75 ml of d ₆ -DMSO by heating at 60 ° C. for 4 to 6 hours.
Measuring instrument: JEM ECA-500 manufactured by JEOL Ltd.
Measurement conditions: measurement temperature 25 ° C., observation nucleus ¹ H, integration number 64 times, repetition time 11 seconds.

(Assignment of spectrum)
The spectra were measured in a dimethylsulfoxide deuterated solvent. The peaks at 0.5 to 1.5 ppm were methacrylic acid, methyl methacrylate, and hydrogen of the α-methyl group of the six-membered cyclic anhydride, 1.6 to 2 peak of .1ppm hydrogen of methylene groups in the polymer backbone, the peak of 3.5ppm hydrogen of the carboxylic acid ester of methyl methacrylate (-COOCH _3), the peak of 12.4ppm is hydrogen of the carboxylic acid of methacrylic acid . The peak at 6.5 to 7.5 ppm is hydrogen in the aromatic ring of styrene. Since the heat-resistant styrene resin composition of the present invention has a low content of a 6-membered cyclic anhydride, it is usually difficult to quantify it by the method of this measurement.

(2) Measurement of Vicat softening temperature (° C):
Vicat softening temperatures of the copolymer resin (a) and the heat-resistant styrene resin composition were measured according to ISO 306. The load was 50 N and the temperature rising rate was 50 ° C./h.

(3) Measurement of weight average molecular weight (10,000):
Sample preparation: About 0.05% by mass of resin was dissolved in tetrahydrofuran.
(Measurement condition)
Equipment: TOSOH HLC-8220GPC
(Gel permeation chromatography)
Column: super HZM-H
Temperature: 40 ° C
Carrier: THF 0.35mL / min
Detector: RI, UV: 254nm
Calibration curve: Standard PS made by TOSOH is used

(4) Measurement of melt flow rate:
The melt flow rates of the copolymer resin (a) and the rubber-modified styrene resin (b) were measured according to ISO 1133. The measurement temperature was 200 ° C. and the load was 49N.

(5) Measurement of rubber particle size:
The rubber particle size of the rubber-modified styrenic resin (b) was measured by taking a 1000 times photograph using a transmission electron microscope by the ultrathin section method, and measuring the particle size of 1000 particles in the photograph to I calculated by the formula.
Rubber particle size = Σni × Di ⁴ / Σni × Di ³
(However, ni is the number of rubber particles having a particle diameter Di. Di was obtained by the average value of the major axis and the minor axis of the particles.)

(6) Measurement of swelling index of toluene insoluble matter:
The swelling index of the toluene-insoluble matter of the rubber-modified styrene resin (b) was measured by the following method. 1 g of rubber-modified styrenic resin (b) was precisely weighed in a settling tube (this mass is W1 (g)), 20 ml of toluene was added, and the mixture was shaken at 23 ° C. for 2 hours and then centrifuged (Hitachi Co., Ltd.). Centrifugation was performed for 60 minutes at 20000 rpm at 10 ° C. or lower with a factory-produced himac, CR-20 (rotor: R20A2)). The settling tube was slowly tilted to about 45 degrees and the supernatant was decanted off. The mass of the insoluble matter (which is a state accompanied by toluene) was precisely weighed (this mass is defined as W2 (g)), and subsequently vacuum dried for 1 hour at 160 ° C. and 3 kPa or less, and then in a desiccator. After cooling to room temperature, the mass of toluene-insoluble matter was precisely weighed (this mass is defined as W3 (g)).
The swelling index of the toluene-insoluble matter was calculated by the following formula.
Swelling index of toluene insoluble matter = (W2 / W3)

(7) Measurement of ratio of mass of toluene insoluble matter / rubber content in toluene insoluble matter:
0.25 g of rubber-modified styrene resin (b) was dissolved in 50 ml of chloroform, iodine monochloride was added to react the double bond in the rubber component, potassium iodide was added, and residual iodine monochloride was added to iodine. And was back titrated with sodium thiosulfate (iodine monochloride method). By this method, the rubber content (W4 (mass%)) in the rubber-modified styrene resin (b) was measured, and from this value, the rubber content in the rubber-modified styrene resin (W1) in the above (6), That is, the rubber content (W5 (g)) in the toluene insoluble matter was determined by the following formula:
Rubber content (W5) in toluene insoluble matter = W1 x W4 / 100
The ratio of the mass of toluene insoluble matter to the content of rubber in toluene insoluble matter (mass of toluene insoluble matter / rubber content in toluene insoluble matter) was calculated by the following formula.
Mass of toluene insoluble matter / rubber content in toluene insoluble matter = W3 / W5

[Injection molding characteristics and injection molding characteristics]
(8) Measurement of Charpy impact strength (kJ / m ² ):
The Charpy impact strength of the test piece obtained from the resin composition was measured according to ISO 179 with a notch.

(9) Bending strength (MPa):
The bending strength of the test piece obtained from the resin composition was measured according to ISO 178.

(10) Flexure (mm):
When measuring the bending strength in (9) above, the maximum amount of deflection was measured.

[Non-foamed extrusion properties and non-foamed extrudate properties]
(11) Measurement of impact strength (kgf · cm) of non-foamed sheet:
The impact strength of a 0.1 mm-thick stretched sheet produced using the resin composition under predetermined conditions was measured with a film impact tester (A121807052) manufactured by Toyo Seiki.

(12) Appearance determination of non-foamed extruded sheet:
Three sheets having a size of 8 cm × 20 cm were cut out from a stretched sheet having a thickness of 0.1 mm prepared using the resin composition under predetermined conditions, and the average diameter of (major axis + minor axis) / 2 on the surface of the three sheets was cut. The number of gels, which are foreign matter of 1 mm or more, was counted, and the appearance was judged according to the following evaluation criteria.
⊚: The number of gels is 2 or less ○: The number of gels is 3 to 5 ×: The number of gels is 6 or more

[Characteristics of foamed extrudate]
(13) Measurement of impact strength (kgf · cm) of foam sheet:
The impact strength of the foamed sheet produced using the resin composition under predetermined conditions was measured with a film impact tester (A121807052) manufactured by Toyo Seiki.

[Recycling characteristics]
(14) Appearance determination of injection-molded product Polypropylene (E-105GM made by Prime Polymer Co., homopolymer, MI: 0.5) was dry blended with 10 parts by mass of the resin composition pellets with respect to 100 parts by mass of the resin composition. Then, injection molding was carried out under the conditions of 230 ° C. and an injection speed of 50% to produce an ISO dumbbell type injection molded product. With respect to the obtained molded product, the presence or absence of surface layer peeling was visually observed and judged according to the following criteria.
○: No peeling ×: Peeling

[Copolymer resin (a)]
(Resin (a-1))
From 71.3 parts by mass of styrene, 7.3 parts by mass of methacrylic acid, 6.4 parts by mass of methyl methacrylate, 15.0 parts by mass of ethylbenzene, and 0.025 parts by mass of 1,1-bis (t-butylperoxy) cyclohexane. At a rate of 1.1 liters / hour, the resulting polymerization raw material composition liquid was introduced into a complete mixing type reactor having a volume of 4 liters, then into a polymerization apparatus comprising a laminar flow type reactor of 2 liters, and then unreacted monomers. Then, the resin was prepared by continuously and sequentially supplying it to a devolatilizer connected to a single-screw extruder for removing volatile matters such as a polymerization solvent. Regarding the polymerization reaction conditions in the polymerization step, the complete mixing reactor had a polymerization temperature of 122 ° C. and the laminar flow reactor had a polymerization temperature of 120 to 142 ° C. The devolatilized unreacted gas was condensed in a condenser in which a refrigerant of -5 ° C was passed and was recovered as an unreacted liquid. The polymer content in the final polymerization solution was measured by the formula [(sample mass after drying / sample mass before drying) × 100%] after drying the polymerization solution at 215 ° C. under reduced pressure of 2.5 kPa for 30 minutes. , 65.6 mass% and the weight average molecular weight was 214,000 (214,000). Table 1 shows the composition ratio, characteristics, etc. of the obtained resin.

(Resin (a-2), (a-3))
Copolymer resin (a) was obtained in the same manner as for resin (a-1) by adjusting the composition, polymerization temperature conditions and the like so as to give the properties of the resin shown in Table 1.

[Rubber modified styrene resin (b)]
(Resin (b-1))
A rubber-modified styrene-based resin was produced using a polymerization apparatus in which three laminar flow reactors (1.5 liters) equipped with a stirrer were connected in series, and then an extruder with a two-stage vent was arranged. 82 parts by mass of styrene, 12 parts by mass of ethylbenzene, 6.7 parts by mass of Diene 55 manufactured by Asahi Kasei Chemicals Corporation as a rubber component, and 0.02 parts by mass of 1,1-bis (t-butylperoxy) cyclohexane in a raw material tank equipped with a stirrer. Was charged, the rubber component was dissolved by a stirrer, and this raw material solution was supplied to the reactor at a volume of 0.75 liters / hour, the temperature of the first stage reactor was 110 to 120 ° C., and the second stage reaction Polymerization was carried out at a machine temperature of 120 to 130 ° C and a third stage reactor temperature of 140 to 150 ° C. The extruder temperature was 210 to 240 ° C., the degree of vacuum was 3 kPa, and the total solid content in the polymerization liquid discharged from the final reactor was 77.9% by mass. The rubber particle size was controlled by adjusting the rotation speed of the stirrer of the first-stage laminar flow reactor to 115 rpm. Table 2 shows the composition and characteristics of the obtained resin.

(Resin (b-2) to (b-4))
The conditions were adjusted so that the properties of the resin shown in Table 2 were obtained, and a rubber-modified styrene resin (b) was obtained in the same manner as the resin (b-1). In order to obtain the rubber particle diameters shown in Table 2, the rotation speeds of the stirrer of the first-stage laminar flow reactor for the resin (b-3) and the resin (b-4) were adjusted to 250 rpm and 20 rpm, respectively. .

[Maleic anhydride-modified ethylene-α-olefin copolymer (c)]
(Resin (c-1))
Scona TSPOE 1002 GBLL (manufactured by Big Chemie, ethylene maleic anhydride / octene copolymer, maleic anhydride content: 1.5% by mass) was used.

(Resin (c-2))
Scona TSPOE 1002 CMB1-2 (manufactured by Big Chemie, ethylene maleic anhydride / octene copolymer, maleic anhydride content 0.55% by mass) was used.

[Core-shell type graft polymer (d)]
(Resin (d-1))
METHYBRENE C-223A manufactured by Mitsubishi Chemical Corporation (butadiene monomer unit content: 70% by mass, total content of methyl methacrylate monomer unit and styrene monomer unit: 29% by mass, methyl methacrylate unit amount) (Body / styrene monomer composition ratio = 1/1, butyl acrylate monomer unit: 1%) was used.

(Resin (d-2))
Metablene W-450A (butyl acrylate monomer unit content: 90 mass%, methyl methacrylate monomer unit content: 10 mass%) manufactured by Mitsubishi Chemical Corporation was used.

[Additive]
(Phenolic antioxidant)
Stearyl 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate (manufactured by BASF, Irganox 1076)

(Phosphorus antioxidant)
Tris (2,4-di-t-butylphenyl) phosphite (BASF Corporation, Irgafos 168)

[Other resins]
MS-SEBS: Maleated styrene-ethylene-butylene-styrene block copolymer (Tuftec M1913 manufactured by Asahi Kasei Chemicals, Inc. (styrene monomer unit content 30% by mass) is a maleic anhydride-modified ethylene-α-olefin copolymer. Used for comparison with (c).

[Examples, Comparative Examples]
(Example 1)
As shown in Table 3 below, 5% by mass of the resin (b-1) as the rubber-modified styrene-based resin (b) was used with respect to 90% by mass of the resin (a-1) as the copolymer resin (a), As the maleic anhydride-modified ethylene-α-olefin copolymer (c), the resin (c-1) was mixed at a ratio of 5 mass% and extruded with a twin-screw extruder to prepare resin pellets.
Using the obtained resin pellets, a non-foamed extrudate (non-foamed extruded sheet) and a foamed extrudate (foamed extruded sheet, and a tray container as a molded product) were produced, and the physical properties and the like were evaluated by the above-mentioned methods. .
As for the non-foamed extruded sheet, a 25 mmφ single-screw sheet extruder manufactured by Soken Co., Ltd. was used to prepare a sheet having a thickness of about 0.7 mm at a resin melting zone temperature of 220 to 230 ° C., and further this sheet was manufactured by Toyo Seiki. After heating at 140 ° C. for 10 minutes with a biaxial stretching device EX6-S1 manufactured by the same company, it was stretched 5 times in the sheet extrusion direction and 1.5 times in the direction perpendicular to the sheet extrusion to produce a sheet of about 0.1 mm. .
The foamed extruded sheet was formed by compression molding and impregnated with a liquefied carbon dioxide gas at 10 mPa for 30 minutes in an autoclave with a thickness of about 0.18 mm, then heated to 117 ° C., the heating time was adjusted appropriately, and about 10 times foamed. A body sheet was produced.
The properties and physical properties of the obtained non-foamed extrudate and foamed extrudate were evaluated by the methods described above, and the results are shown in Table 3 below.

(Examples 2 to 10)
The copolymer resin (a), the rubber-modified styrene resin (b), the maleic anhydride-modified ethylene-α-olefin copolymer (c) in the proportions shown in Table 3 below, and optionally a core-shell type graft polymer ( d) was mixed and extruded with a twin-screw extruder to produce resin pellets, and a non-foamed extrudate and a foamed extrudate were produced in the same manner as in Example 1, and their properties and physical properties were evaluated. The evaluation results are shown in Table 3 below. The stretching temperature of the sheet and the foaming temperature of the sheet containing liquefied carbon dioxide were increased or decreased by the difference in the Vicat softening temperature from Example 1.

(Comparative Example 1)
Except that 85% by mass of the resin (a-1) as the copolymer resin (a) and 15% by mass of the resin (b-1) as the rubber-modified styrene resin (b) were mixed. A non-foamed extrudate and a foamed extrudate were prepared in the same manner as in Example 1. The evaluation results of properties and physical properties of the obtained product are shown in Table 3 below. In Comparative Example 1, only the copolymer resin (a) and the rubber-modified styrene resin (b) were used, and the maleic anhydride-modified ethylene-α-olefin copolymer (c) was not added. Compared to Example 1, the Charpy impact strength, the impact strength of the non-foamed sheet and the foamed sheet, and the appearance of the non-foamed sheet were inferior.

(Comparative Examples 2 to 4)
Non-foamed extrudates and foamed extrudates were prepared in the same manner as in Example 1 at the ratios shown in Table 3. The evaluation results of properties and physical properties of the obtained product are shown in Table 3 below. Since the compounding amount of the rubber-modified styrene resin (b) or the maleic anhydride-modified ethylene-α-olefin copolymer (c) is outside the range of the present invention, Comparative Examples 2 to 4 have impact resistance and heat resistance. , The recycling characteristics were not satisfactory.

(Comparative example 5)
Non-foamed extrudates and foamed extrudates were prepared in the same manner as in Example 1 at the ratios shown in Table 3. The evaluation results of properties and physical properties of the obtained product are shown in Table 3 below. It can be seen that when a maleated styrene-ethylene-butylene-styrene block copolymer is used instead of the maleic anhydride-modified ethylene-α-olefin copolymer (c), the Vicat softening point (heat resistance) is greatly reduced.

According to the present invention, a heat-resistant styrene-based resin composition having excellent heat resistance, mechanical strength, appearance, and recyclability, a non-foamed and foamed extruded sheet formed using the heat-resistant styrene-based resin composition, and A molded article molded using the sheet can be provided.
Further, non-foamed and foamed extruded plates and extruded sheets using the heat-resistant styrene-based resin composition of the present invention, as well as molded articles such as food containers and packaging materials obtained by secondary processing of these, have heat resistance and mechanical properties. Excellent strength and appearance. Furthermore, the heat-resistant styrene-based resin composition of the present invention can be widely used as a raw material for molded articles by injection molding and the like for applications such as electric product parts, toys, miscellaneous goods, daily necessities, and various industrial parts. It plays a big role.

Claims (9)

Copolymer resin (a) containing a styrene-based monomer unit, an unsaturated carboxylic acid-based monomer unit, and an unsaturated carboxylic acid ester-based monomer unit, a rubber-modified styrene-based resin (b), and maleic anhydride A heat-resistant styrene-based resin composition containing an acid-modified ethylene-α-olefin copolymer (c),
When the total mass of the copolymer resin (a), the rubber-modified styrene resin (b), and the maleic anhydride-modified ethylene-α-olefin copolymer (c) is 100% by mass, the copolymer resin The content of (a) is 60 to 94% by mass, the content of the rubber modified styrene resin (b) is 5 to 30% by mass, and the maleic anhydride modified ethylene-α-olefin copolymer (c) is contained. Content is 1-10 mass%, The heat-resistant styrene resin composition characterized by the above-mentioned. When the copolymer resin (a) has a total content of styrene-based monomer units, unsaturated carboxylic acid-based monomer units, and unsaturated carboxylic acid ester-based monomer units as 100% by mass, It contains 69 to 96 mass% of a styrene-based monomer unit, and contains 4 to 16 mass% of the unsaturated carboxylic acid-based monomer unit, and contains the unsaturated carboxylic acid ester-based monomer unit. Contains 0 to 15 mass%,
The rubber content of the rubber-modified styrene-based resin (b) is 5 to 15 mass% when the content of the rubber-modified styrene-based resin (b) is 100 mass%, and the rubber-modified styrene is The heat-resistant styrene resin composition according to claim 1, wherein the rubber particle diameter of the resin (b) is 0.5 to 5.0 μm.   The heat-resistant styrene-based resin composition according to claim 1 or 2, wherein the α-olefin of the maleic anhydride-modified ethylene-α-olefin copolymer (c) has 3 to 8 carbon atoms.   The maleic anhydride grafting ratio of the maleic anhydride-modified ethylene-α-olefin copolymer (c) is such that the content of the maleic anhydride-modified ethylene-α-olefin copolymer (c) is 100% by mass. The heat-resistant styrene-based resin composition according to claim 1, wherein the heat-resistant styrene-based resin composition is 0.5 to 1.5 mass%.   The heat-resistant styrene-based resin composition according to any one of claims 1 to 4, wherein the maleic anhydride-modified ethylene-α-olefin copolymer (c) is a maleic anhydride ethylene-octene copolymer.   Further, the core-shell type graft polymer (d) is added to the copolymer resin (a), the rubber-modified styrene resin (b), and the maleic anhydride-modified ethylene-α-olefin copolymer (c) in a total mass of 100. The heat-resistant styrene-based resin composition according to claim 1, wherein the heat-resistant styrene-based resin composition is contained in an amount of 1 to 10 parts by weight based on parts by weight.   A non-foamed extruded sheet formed using the heat-resistant styrene-based resin composition according to claim 1.   A foamed extruded sheet formed using the heat-resistant styrene-based resin composition according to claim 1. A molded article formed using the non-foamed extruded sheet according to claim 7 or the foamed extruded sheet according to claim 8.