JP2020189900A - Thermostable styrene-based resin composition, sheet, and molded article - Google Patents

Abstract

To provide a thermostable styrene-based resin composition excellent in thermal resistance, mechanical strength, appearance, oil resistance, and moldability and nonfoam and foam extruded sheets and molded articles formed from the thermostable styrene-based resin composition.SOLUTION: A thermostable styrene-based resin composition contains a copolymer resin (a) of 80-91 mass% that has a content of a styrene-based monomer unit of 86-94 mass%, a content of unsaturated carboxylic acid-based monomer unit of 6-14 mass%, and a weight average molecular weight of 150,000-240,000; and a rubber-modified styrene-based resin (b) of 9-20 mass% that has a rubber content in the rubber-modified styrene-based resin of 8-15 mass% and a rubber particle size of 2.7-5.3 μm.SELECTED DRAWING: None

Description

The present invention is a heat-resistant styrene resin composition having excellent heat resistance, mechanical strength, appearance, oil resistance, and moldability, and a non-foamed and foamed extruded sheet formed by using the heat-resistant styrene resin composition. And molded products.

Since styrene-methacrylic acid resin has excellent heat resistance and is relatively inexpensive, it can be used for food containers such as lunch boxes and prepared foods, packaging materials, foam boards for heat insulating materials for houses, and diffusion of LCD TVs containing diffusers. Widely used for boards and the like. In recent years, in order to popularize microwave ovens used for business purposes such as convenience stores and to shorten the usage time of microwave ovens, higher output devices that tend to reach higher temperatures in a short time have been used. In addition, the number of food prepared foods using cooking oil increases, and the temperature tends to be high. Therefore, a resin having more heat resistance and more excellent oil resistance is desired. Further, the use of deep-drawing containers made of foam is increasing for food containers such as prepared foods, and a resin capable of deep-drawing molding with foam is desired.

Generally, in order to obtain a resin having higher heat resistance and excellent mechanical strength, a rubber component is added to a styrene-methacrylic acid-based resin having a higher methacrylic acid content, and the rubber component is, for example, impact-resistant rubber. A modified styrene resin, a styrene-butadiene copolymer resin, or the like is used. Regarding these, Patent Document 1 below discloses a laminated foam sheet for molding a container for microwave cooking, which is composed of styrene-acrylic acid resin and high-impact styrene as a rubber component. Further, Patent Document 2 below discloses a heat-resistant foamed sheet made of styrene-methacrylic acid resin and impact-resistant polystyrene (HIPS), and further, a heat-resistant foamed sheet made by laminating a polyester film and a polyolefin film. Further, Patent Document 3 below discloses a resin composition composed of a high molecular weight styrene-methacrylic acid resin having a weight average molecular weight of 250,000 to 800,000 and an impact-resistant styrene resin. Further, Patent Document 4 below discloses a foamed sheet made of impact-resistant polystyrene containing rubber having a styrene-methacryl rubber particle diameter of 0.8 μm or more and less than 1.8 μm.

Japanese Unexamined Patent Publication No. 63-264335 Japanese Unexamined Patent Publication No. 02-58548 Japanese Unexamined Patent Publication No. 2000-72942 JP-A-2018-44086

However, the above-mentioned composition of the styrene-methacrylic acid resin and the impact-resistant styrene resin of the prior art is not sufficient in terms of heat resistance, mechanical strength, appearance, oil resistance, and moldability. In particular, there is a demand for a resin that maintains heat resistance and mechanical strength and is more excellent in oil resistance and deep drawing property.

Under such circumstances, the problem to be solved by the present invention is to use a heat-resistant styrene resin composition having excellent heat resistance, mechanical strength, appearance, oil resistance, and moldability, and the heat-resistant styrene resin composition. To provide non-foamed and foamed extruded sheets and molded articles formed in the above.

As a result of diligent studies in view of the current situation, the present inventors have obtained a copolymer resin containing a specific styrene-based monomer unit and an unsaturated carboxylic acid-based monomer unit, and a specific rubber-modified styrene-based resin. A heat-resistant styrene-based resin composition capable of obtaining a non-foamed sheet, a foamed sheet, and a molded product having excellent heat resistance, mechanical strength, appearance, oil resistance, and moldability in a resin mixed with a resin in a specific ratio. That is, the present invention is as follows.

(1) A heat-resistant styrene resin composition containing a copolymer resin (a) containing a styrene-based monomer unit and an unsaturated carboxylic acid-based monomer unit, and a rubber-modified styrene resin (b). ,
When the total content of the copolymer resin (a) and the rubber-modified styrene resin (b) is 100% by mass, the content of the copolymer resin (a) is 80 to 91% by mass. The content of the rubber-modified styrene resin (b) is 9 to 20% by mass.
The copolymerized resin (a) contains the styrene-based monomer unit when the total content of the styrene-based monomer unit and the unsaturated carboxylic acid-based monomer unit is 100% by mass. Is 86 to 94% by mass, the content of the unsaturated carboxylic acid-based monomer unit is 6 to 14% by mass, and the weight average molecular weight is 150,000 to 240,000.
The rubber-modified styrene resin (b) has a rubber content of 8 to 15% by mass and a rubber particle diameter of 2 when the total mass of the rubber-modified styrene resin (b) is 100% by mass. A heat-resistant styrene-based resin composition having a thickness of 7.7 to 5.3 μm.
(2) The ratio of the melt viscosity of the rubber-modified styrene resin (b) to the melt viscosity of the copolymer resin (a) when the melt temperature of the resin is 240 ° C. and the shear rate is 400 (1 / s). The heat-resistant styrene resin composition according to (1) above, wherein (resin (b) / resin (a)) is 0.6 to 1.4.
(3) The swelling index of the toluene-insoluble matter of the rubber-modified styrene resin (b) is 8 to 15, and the mass ratio of the toluene-insoluble matter to the rubber content in the toluene-insoluble matter (toluene-insoluble matter /). The heat-resistant styrene-based resin composition according to (1) or (2) above, wherein the rubber content in the toluene insoluble content) is 2.0 to 3.4.
(4) The heat-resistant styrene-based resin composition according to any one of (1) to (3) above, wherein the bicut softening temperature of the heat-resistant styrene-based resin composition is 109 ° C. or higher.
(5) When the total content of the copolymerized resin (a) and the rubber-modified styrene resin (b) is 100 parts by mass, the freezing point is −10 ° C. or lower and the number of carbon atoms is 14 or more. The heat-resistant styrene resin composition according to any one of (1) to (4) above, which contains 0.01 to 1.0 parts by mass of the aliphatic primary alcohol.
(6) When the total content of the copolymerized resin (a) and the rubber-modified styrene resin (b) is 100 parts by mass, the plasticizer is contained in an amount of 0.01 to 1.0 parts by mass. The heat-resistant styrene resin composition according to any one of (1) to (5).
(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 foam 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 by using the non-expanded extruded sheet according to (7) above or the extruded foam sheet according to (8) above.

According to the present invention, a heat-resistant styrene-based resin composition having excellent heat resistance, mechanical strength, appearance, oil resistance, and moldability, and non-foaming and foaming formed by using the heat-resistant styrene-based resin composition. Extruded sheets and molded articles can be provided.

Hereinafter, embodiments 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-based resin composition of the present embodiment contains a copolymer resin (a) containing a styrene-based monomer unit and an unsaturated carboxylic acid-based monomer unit, and a rubber-modified styrene-based resin (b). When the total content of the copolymer resin (a) and the rubber-modified styrene resin (b) is 100% by mass, the content of the copolymer resin (a) is 80 to 91% by mass, and the rubber-modified styrene. The content of the system resin (b) is 9 to 20% by mass. Further, in the heat-resistant styrene-based resin composition of the present embodiment, when the total content of the styrene-based monomer unit and the unsaturated carboxylic acid-based monomer unit of the copolymer resin (a) is 100% by mass. , The content of the styrene-based monomer unit is 86 to 94% by mass, the content of the unsaturated carboxylic acid-based monomer unit is 6 to 14% by mass, and the weight average molecular weight is 150,000 to 240,000. Is. Further, in the heat-resistant styrene resin composition of the present embodiment, the rubber-modified styrene resin (b) has a rubber content of 8 to 15 when the total mass of the rubber-modified styrene resin (b) is 100% by mass. It is mass% and has a rubber particle diameter of 2.7 to 5.3 μm.
Hereinafter, the heat-resistant styrene resin composition is also referred to as a resin composition, the copolymer resin (a) is referred to as a component (a), and the rubber-modified styrene resin (b) is also referred to as a component (b).

<Copolymerized resin (a)>
The resin composition of the present embodiment contains the copolymer resin (a) in an amount of 80 to 91% by mass, preferably 80 to 91% by mass, when the total content of the component (a) and the component (b) is 100% by mass. It contains 81 to 90% by mass, more preferably 82 to 89% by mass of the copolymer resin (a). In the present embodiment, the heat resistance and rigidity can be improved by setting the content of the component (a) to 80% by mass or more. Further, by setting the content of the component (a) to 91% by mass or less, the mechanical strength can be improved.

In the present embodiment, when the copolymer resin (a) is 100% by mass, the content of the styrene-based monomer unit is 86 to 94% by mass, preferably 88 to 93% by mass, and more preferably 90. It is in the range of ~ 93% by mass. If the content of the styrene-based monomer unit is less than 86% by mass, the fluidity of the resin is lowered. On the other hand, if it exceeds 94% by mass, a desired amount of the unsaturated carboxylic acid-based monomer unit described later cannot be present.

Examples of the styrene-based monomer used in the copolymerized resin (a) in the present embodiment and the rubber-modified styrene-based resin (b) described later include α-methylstyrene and α-methyl-p-methylstyrene, in addition to styrene. Examples thereof include ο-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene, ethylstyrene, isobutylstyrene, and t-butylstyrene or bromostyrene, chlorostyrene, and inden. In particular, styrene is preferable. One or more of these styrene-based monomers can be used.

In the resin composition of the present embodiment, the unsaturated carboxylic acid-based monomer plays a role of improving heat resistance. When the total content of the styrene-based monomer unit and the unsaturated carboxylic acid-based monomer unit of the copolymer resin (a) is 100% by mass, the content of the unsaturated carboxylic acid-based monomer unit is 6. It is in the range of ~ 14% by mass, preferably 7 to 12% by mass, and more preferably 7 to 10% by mass. When the content of the unsaturated carboxylic acid-based monomer unit is less than 6% by mass, the effect of improving the heat resistance is insufficient. On the other hand, if it exceeds 14% by mass, the amount of gelled product in the copolymer resin increases, resulting in poor appearance. Further, the fluidity of the copolymerized resin is lowered and the moldability such as deep drawing is lowered, which is not preferable. Furthermore, the mechanical strength is also lowered, which is not preferable.

In the present embodiment, the unsaturated carboxylic acid-based monomer is not particularly limited, and 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 has excellent handleability. These unsaturated carboxylic acid-based monomers can be used alone or in combination of two or more.

In the present embodiment, the weight average molecular weight of the copolymer resin (a) is 150,000 to 240,000, preferably 160,000 to 230,000, and more preferably 170,000 to 220,000. If the weight average molecular weight is less than 150,000, the mechanical strength is inferior. On the other hand, if it exceeds 240,000, the amount of gelled product in the copolymer resin increases, resulting in poor appearance. Further, the fluidity of the copolymer resin and the moldability such as deep drawing are lowered, which is not preferable.

The polymerization method of the copolymer resin (a) according to the present embodiment is not particularly limited, but it is preferable to adopt a massive polymerization method or a solution polymerization method as the radical polymerization method. The polymerization method mainly comprises a polymerization step of polymerizing a polymerization raw material (monomer component) and a devolatilization step of removing volatile components such as unreacted monomer and polymerization solvent from the polymerization product. Hereinafter, the polymerization method of the copolymer resin (a) according to the present embodiment will be described.

When the polymerization raw material is polymerized in order to obtain the copolymerized resin (a) according to the present embodiment, a polymerization initiator and a chain transfer agent are typically contained in the polymerization raw material composition. Examples of the polymerization initiator include organic peroxides such as 2,2-bis (t-butylperoxy) butane, 1,1-bis (t-butylperoxy) cyclohexane, and n-butyl-4,4-bis (t-). Butylperoxy) Peroxyketals such as valerate, di-t-butyl peroxide, t-butylcumyl peroxide, dialkyl peroxides such as dicumyl peroxide, diacyl peroxides such as acetyl peroxide and isobutylyl peroxide, diisopropyl peroxydicarbonate. Peroxydicarbonates such as, peroxyesters such as t-butylperoxyacetate, ketone peroxides such as acetylacetone peroxide, hydroperoxides such as t-butylhydroperoxide and the like can be mentioned. From the viewpoint of decomposition rate and polymerization rate, 1,1-bis (t-butylperoxy) cyclohexane is particularly preferable.

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

As a polymerization method, solution polymerization using a polymerization solvent can be adopted, if necessary. Examples of the polymerization solvent used include aromatic hydrocarbons such as ethylbenzene and dialkyl ketones such as methyl ethyl ketone, which may be used alone or in combination of two or more. 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 a range not exceeding 25 parts by mass with respect to 100 parts by mass of all the monomers. When 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 decrease and the impact strength of the obtained resin tends to decrease significantly. Before polymerization, it is preferable to add 5 to 20 parts by mass with respect to 100 parts by mass of all the monomers because the quality can be easily made uniform and the polymerization temperature can be controlled.

The apparatus used in the polymerization step for obtaining the copolymerized resin (a) according to the present embodiment 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, a polymerization apparatus in which one or a plurality of completely mixed reactors are connected can be used. Further, the volatilization step is also not particularly limited, and when the bulk polymerization is carried out, the polymerization is finally proceeded until the unreacted monomer is preferably 50% by mass or less, more preferably 40% by mass or less, and such unreacted monomer is obtained. In order to remove volatile components such as monomers, devolatile treatment is performed by a known method. For example, a normal volatilizer such as a flash drum, a twin-screw volatilizer, a thin film evaporator, or an extruder can be used, but a volatilizer having a small retention portion is preferable. The temperature of the devolatilization treatment is usually about 190 to 270 ° C, preferably 200 to 260 ° C, and more preferably 210 to 250 ° C. The pressure of the devolatilization treatment is usually about 0.13 to 4 kPa, preferably 0.13 to 3 kPa, and more preferably 0.13 to 2.0 kPa. As the volatilization method, for example, a method of removing volatile matter by reducing the pressure under heating and a method of removing volatile matter through an extruder designed for the purpose of removing volatile matter are desirable.

<Rubber-modified styrene resin (b)>
The resin composition of the present embodiment contains the rubber-modified styrene resin (b) in an amount of 9 to 20% by mass when the total content of the component (a) and the component (b) is 100% by mass. It preferably contains 10 to 19% by mass, and more preferably 11 to 18% by mass of the copolymer resin (a). In the present embodiment, by containing the component (b) in an amount of 9 to 20% by mass, a resin composition having excellent heat resistance, mechanical strength, appearance, oil resistance, and moldability can be obtained. Further, by setting the content of the component (b) to 9% by mass or more, the mechanical strength can be improved. Further, by setting the content of the component (a) to 20% by mass or less, heat resistance and rigidity can be improved.

The rubber-modified styrene resin (b) in the present embodiment is a resin in which particles of a rubber-like polymer are dispersed in a styrene-based resin matrix, and the styrene-based monomer is polymerized in the presence of the rubber-like polymer. Can be manufactured by

As the rubber-like polymer, polybutadiene, polyisoprene, natural rubber, polychloroprene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer and the like can be used, but polybutadiene or styrene-butadiene copolymer is preferable. As the polybutadiene, both high cis polybutadiene having a high cis content and low cis polybutadiene having a low cis content can be used. Further, as the structure of the styrene-butadiene copolymer, both a random structure and a block structure can be used. One or more of these rubbery polymers can be used. Further, saturated rubber obtained by hydrogenating butadiene rubber can also be used. In particular, high cis polybutadiene having a high cis content is preferable.

The rubber content of the rubber-modified polystyrene-based resin (b) is 8 to 15% by mass, preferably 9 to 14% by mass, and more preferably 10 to 13% by mass. When the rubber content is less than 8% by mass, the composition with the copolymer resin (a) is not preferable because the mechanical strength is lowered. On the other hand, when the rubber content exceeds 15% by mass, heat resistance and rigidity are lowered, which is not preferable. Further, when the rubber-modified polystyrene-based resin (b) is produced, the viscosity of the polymerization system becomes high, which makes the operation difficult. Further, it becomes difficult to make the rubber particles finer, and when the rubber particles are mixed with the copolymer resin (a), the rubber component is poorly dispersed, the mechanical strength is lowered, and the appearance of the product is poor, which is not preferable. The rubber content in the rubber-modified polystyrene-based resin (b) can be determined by an iodine reduction titration method or the like.

The rubber particle diameter is 2.7 to 5.3 μm, preferably 3.0 to 5.0 μm, and more preferably 3.3 to 4.7 μm. When the rubber particle diameter is less than 2.7 μm, the composition with the copolymer resin (a) is inferior in mechanical strength. In addition, oil resistance tends to decrease. On the other hand, when the rubber particle diameter exceeds 5.3 μm, the composition with the copolymer resin (a) is inferior in mechanical strength and appearance. The mechanical strength has a range of appropriate rubber particle diameters. The rubber-modified polystyrene-based resin (b) is obtained by polymerizing a styrene-based monomer in a reactor equipped with a stirrer in the presence of a rubber-like polymer, and the rubber particle size is the number of revolutions of the stirrer and the rubber used. It can be adjusted by the molecular weight of the polymer.

The method for producing the rubber-modified styrene resin (b) is not particularly limited, but bulk polymerization (or solution polymerization) in which the styrene-based monomer (and solvent) is polymerized in the presence of the rubber-like polymer, Alternatively, it can be produced by bulk-suspension polymerization that shifts to suspension polymerization during the reaction, or by emulsion graft polymerization that polymerizes a styrene-based monomer in the presence of a rubbery polymer latex. In bulk polymerization, a mixed solution containing a rubber-like polymer, a styrene-based monomer, and an organic solvent, an organic peroxide, and / or a chain transfer agent as required is mixed with a complete mixed reactor or a tank type reaction. It can be manufactured by continuously supplying a vessel and a plurality of tank reactors to a polymerization apparatus configured by connecting them in series.

In the present embodiment, the ratio of the melt viscosity of the rubber-modified styrene resin (b) to the melt viscosity of the copolymer resin (a) (resin (resin (resin)) is obtained by mixing the copolymer resin (a) and the rubber-modified styrene resin (b). b) / resin (a)) is preferably 0.6 to 1.4. It is more preferably 0.7 to 1.3, and even more preferably 0.8 to 1.2. The copolymer resin (a) is a copolymer of a styrene-based monomer and an unsaturated carboxylic acid-based monomer, and the unsaturated carboxylic acid-based monomer has a stronger polarity than the styrene-based monomer and is non-polymerized. The higher the content of the saturated carboxylic acid-based monomer, the lower the compatibility with polystyrene. Since the matrix of the rubber-modified styrene resin (b) is composed of a styrene resin, the compatibility with the copolymer resin (a) having a large content of unsaturated carboxylic acid monomer is deteriorated, and there is a risk of phase separation. There is. Therefore, unless the copolymer resin (a) and the rubber-modified styrene resin (b) are mixed more uniformly and the rubber-modified styrene resin (b) having a small mixing ratio is dispersed more finely, the mechanical strength and appearance must be increased. , It becomes difficult to obtain products having excellent oil resistance and moldability. Then, in order to mix each component more uniformly and to disperse the component (b) more finely, it is effective to bring the melt viscosities of the copolymer resin (a) and the rubber-modified styrene resin (b) close to each other. By setting the melt viscosity ratio of the copolymer resin (a) and the rubber-modified styrene resin (b) to the range of 0.6 to 1.4, mechanical strength, appearance, oil resistance, moldability, etc. A better resin composition can be obtained.
The above-mentioned melt viscosity is a value measured when the melt temperature of the resin to be measured is 240 ° C. and the shear rate is 400 (1 / s).

In the present embodiment, the swelling index of the toluene-insoluble matter of the rubber-modified styrene resin (b) is 8 to 15, and the mass ratio of the rubber content in the toluene-insoluble matter and the toluene-insoluble matter (toluene-insoluble matter / toluene-insoluble matter). The rubber content in the toluene) is preferably 2.0 to 3.4. The swelling index is more preferably 9 to 14, still more preferably 10 to 13, and the ratio of the rubber content in the toluene insoluble content / toluene insoluble content is more preferably 2.2 to 3.2, still more preferably. It is 2.4 to 3.0. The swelling index of the insoluble toluene is an index showing the degree of cross-linking of the rubber component in the rubber particle diameter. The smaller the value, the higher the cross-linking density, the less flexible the rubber component, the harder it becomes, and the more difficult it is to deform. On the other hand, the larger the value, the lower the crosslink density, the more flexible the rubber component is, and the easier it is to denature. By appropriately adjusting the degree of cross-linking of this rubber component, excellent mechanical strength can be exhibited. Further, in the mass ratio of the toluene insoluble matter and the rubber content in the toluene insoluble matter, if this mass ratio is too small, the amount of the polystyrene component contained in the rubber particle diameter becomes small, and the volume of the toluene insoluble matter, that is, rubber. The volume of the phase decreases. Therefore, the distance between the dispersed rubber particles becomes long, and the mechanical strength tends to decrease. On the other hand, if the mass ratio of the toluene insoluble matter and the rubber content in the toluene insoluble matter is too large, the amount of the polystyrene component contained in the rubber particle diameter increases, and the volume of the rubber phase increases. The viscoelasticity of the product increases, the stretchability of the resin composition decreases, and the moldability such as deep drawability tends to be impaired. When the swelling index of the toluene-insoluble component of the rubber-modified styrene resin (b) is adjusted to 8 to 15, and the ratio of the rubber content in the toluene-insoluble component / toluene-insoluble component is adjusted to the range of 2.0 to 3.4, A resin composition having better mechanical strength and deep drawability can be obtained.

<Other ingredients>
The resin composition of the present embodiment may contain, if desired, commonly used additives such as lubricants, antioxidants, UV absorbers, mold release agents, plasticizers, dyes, pigments, various fillers and the like. Can be added, and the resin composition to which such an additive is added can be used for various moldings. The above additive may be added in advance at the time of producing the copolymerized resin (a).

The resin composition of the present embodiment contains an aliphatic primary alcohol having a freezing point of −10 ° C. or lower and a carbon number of 14 or more, and the total content of the components (a) and (b) is 100. It may be contained in an amount of 0.01 to 1.0 parts by mass with respect to parts by mass. The aliphatic primary alcohol can be added at both the time of melt mixing of the copolymer resin (a) and the rubber-modified styrene resin (b) and the time of production of the copolymer resin (a). The addition of an aliphatic primary alcohol is effective in suppressing the cross-linking of unsaturated carboxylic acid-based monomers. In particular, it is desirable to add it during the production of the copolymer resin (a). Alcohols having less than 14 carbon atoms are liable to volatilize when a high vacuum is applied for the purpose of removing low volatile components such as residual monomers or water during the production of the copolymer resin (a), extrusion of sheets, etc. The effect of suppressing the chemical reaction diminishes. The content of the aliphatic primary alcohol having 14 or more carbon atoms in the resin composition is preferably 0.01 to 1.0 parts by mass. The content of the aliphatic primary alcohol is more preferably 0.03 to 0.8 parts by mass, still more preferably 0.05 to 0.6 parts by mass. When the content is less than 0.01 parts by mass, the effect of suppressing the gelation reaction tends to be weakened, while when the content exceeds 1.0 parts by mass, the effect of suppressing the gelation reaction is high. , The decrease in heat resistance of the resin tends to be large. In addition, during extrusion molding, it is generated as a dice outlet at the die outlet, and tends to adhere to the sheet and become a foreign substance. Among the aliphatic primary alcohols having 14 or more carbon atoms, iso-type aliphatic primary alcohols having a freezing point of −10 ° C. or lower are particularly preferable. When the freezing point exceeds −10 ° C., and when a high vacuum is applied for the purpose of removing low volatile components such as water and residual monomers, the alcohol tends to precipitate in a condenser or the like, which may reduce the degree of vacuum. The content of an aliphatic primary alcohol having 14 or more carbon atoms can be measured by gas chromatography.

Examples of the aliphatic primary alcohol having 14 or more carbon atoms include n-myristic acid alcohol, n-palmitate alcohol, n-stearyl alcohol and the like. Further, as isoaliphatic primary alcohols 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 iso octadecanol having 20 carbon atoms are used. Eikosanol can be mentioned, for example, 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 can be mentioned. Of these, isooctadecanol having 18 carbon atoms is particularly preferable.

The resin composition of the present embodiment may contain a plasticizer in an amount of 0.01 to 1.0 parts by mass with respect to 100 parts by mass of the total content of the component (a) and the component (b). It is more preferably 0.03 to 0.8 parts by mass, and further preferably 0.05 to 0.6 parts by mass. The addition of the plasticizer improves the stretchability of the resin and is effective for deep drawing, but when the addition amount is less than 0.01 parts by mass, the effect is small. On the other hand, when it exceeds 1.0 part by mass, the heat resistance of the resin tends to decrease significantly. In addition, during extrusion molding, it is generated as a dice outlet at the die outlet, and tends to adhere to the sheet and become foreign matter. Examples of the type of plasticizer include liquid paraffin (also referred to as white oil), white mineral oil, and phthalates. Of these, liquid paraffin (white oil) is particularly preferable.

The resin composition of the present embodiment may further contain a stabilizer. Common stabilizers include, for example, hindered phenols such as octadecyl-3- (3,5-t-butyl-4-hydroxyphenyl) propionate and 4,6-bis (octylthiomethyl) -o-cresol. Examples thereof include antioxidants and phosphorus-based processing heat stabilizers such as tris (2,4-di-t-butylphenyl) phosphite. These stabilizers can be used alone or in combination of two or more. The timing of addition is not particularly limited, and for example, it can be added in a resin polymerization step or a volatilization step, or can be added at the time of resin extrusion with a sheet extruder or a foam extruder.

The resin composition of the present embodiment contains 80 to 91% by mass of the copolymer resin (a) and 9 to 20% by mass of the rubber-modified styrene resin (b), but the resin composition of the present embodiment has , The above-mentioned copolymer resin (a), rubber-modified styrene resin (b), aliphatic primary alcohol, and resins other than plasticizers, for example, general polystyrene, styrene-butadiene block, random copolymerization. It should be understood that the inclusion of elastomers, partially or fully hydrogenated styrene-butadiene copolymer elastomers, polyphenylene ethers, etc. is not excluded. For example, the resin composition of the present embodiment may be filled with commonly used additives such as lubricants, antioxidants, UV absorbers, mold release agents, plasticizers, dyes, pigments, as desired. Agents and the like can be added.

Further, in the present embodiment, the total content of the component (a) and the component (b) in the resin composition is preferably 97% by mass or more, more preferably 97% by mass or more, based on 100% by mass of the resin composition. Is 98% by mass or more, more preferably 99% by mass or more.

<Characteristics of heat-resistant styrene resin composition>
The resin composition of the present embodiment preferably has a Vicat softening temperature of 109 ° C. or higher, more preferably 110 ° C. or higher, and even more preferably 111 ° C. or higher. When the Vicat softening temperature is 109 ° C. or higher, the deformation of the sheet is small and good even at a temperature higher than boiling water. The Vicat softening temperature can be achieved by adjusting the Vicat softening temperature of the copolymer resin (a) used, the Vicat softening temperature of the rubber-modified styrene resin (b) used, and the mixing ratio of both. The rubber-modified styrene resin (b) is easier to manufacture as the rubber content is smaller, but it is necessary to increase the addition amount in order to increase the mechanical strength, and in this case, the heat resistance is lowered, which is not preferable. In order to obtain a resin composition having higher heat resistance and excellent mechanical strength, a copolymer resin (a) having higher heat resistance and a rubber-modified styrene resin (b) having a higher rubber content are used. It is preferable to mix. However, the copolymerized resin (a) having high heat resistance has a limitation in production. The increase in unsaturated carboxylic acid-based monomers lowers the fluidity and increases the production of gels, resulting in lower quality. Further, there is a limit in producing the rubber-modified styrene resin (b) having a high rubber content. As the rubber concentration increases, the viscosity of the polymerization system increases, which makes production extremely difficult. The Vicat softening temperature of the resin composition of the present embodiment is preferably 130 ° C. or lower, more preferably 125 ° C. or lower. If the Vicat softening temperature is too high, it is necessary to raise the resin temperature during thermal processing, and at this time, gels are likely to be generated, which tends to cause a decrease in mechanical strength and a poor appearance.

<Manufacturing method of heat-resistant styrene resin composition>
The method for producing the heat-resistant styrene resin composition is not particularly limited, but the copolymer resin (a) and the rubber-modified styrene resin (b) are mixed (melt-kneaded) with an extruder or the like to form pellets, for example. You can get it. Further, a non-foam extruded sheet or a foam extruded sheet may be manufactured using the heat-resistant styrene resin composition, or the copolymer resin (a) and the rubber-modified styrene resin (b) may be directly applied to the popper of the sheet extruder. It is also possible to produce non-foam extruded sheets, foam extruded sheets and the like by charging and mixing.

[Extruded sheet]
The non-foam extruded sheet and the foam extruded sheet of the present embodiment are formed by using the resin composition of the above-described embodiment of the present invention.
As a method for producing the extruded sheet, a commonly known method can be used. Examples of the method for producing a non-foaming extrusion sheet include a method of using a short-screw or twin-screw extrusion molding machine to which a T-die is attached and a device for picking up the sheet with a uniaxial or biaxial stretching machine. Further, as a method for manufacturing the foam extrusion sheet, a method using an extrusion foam molding machine equipped with a T die or a circular die can be mentioned.

When forming an effervescent extruded sheet, commonly used substances can be used as the effervescent agent and effervescent nucleating agent during extrusion foaming. Butane, pentane, chlorofluorocarbon, carbon dioxide, water and the like can be used as the foaming agent, and butane is preferable. Further, talc or the like can be used as the effervescent nucleating agent.

In the non-foam extruded sheet, for example, the thickness is preferably about 0.1 to 1.5 mm from the viewpoint of rigidity and thermoforming cycle. Further, the non-foamed extruded sheet may be formed only by ordinary low-magnification roll stretching, but in particular, a sheet stretched about 1.3 to 7 times with a roll and then stretched about 1.3 to 7 times with a tenter. Is preferable in terms of strength. Further, the non-foam extruded sheet may be used in a multi-layered manner with a styrene resin such as polystyrene resin, for example, high impact polystyrene composed of a rubber component such as a styrene-butadiene block copolymer or polybutadiene, and further, the styrene resin. It may be used in multiple layers with a resin other than the resin. Examples of the resin other than the styrene resin include PP resin, PP / PS resin, PET resin, nylon resin and the like.

On the other hand, foamed extruded sheets, it is preferred, is preferably an apparent density of 50 g / to 300 g / L, also basis weight 80g / m ² ~500g / m ² it is thick 0.5mm~5.0mm Is preferable. Further, the foam extruded sheet may be used in multiple layers with a styrene resin such as polystyrene resin, for example, high impact polystyrene (impact resistant polystyrene) composed of a rubber component such as a styrene-butadiene block copolymer or polybutadiene. Further, it may be used in multiple layers with a resin other than the styrene resin. Examples of the resin other than the styrene resin include polypropylene (PP) resin, PP / polystyrene (PS) resin, polyethylene terephthalate (PET) resin, nylon resin and the like.

[Molding]
The molded product of the present embodiment is formed by using the non-foam extruded sheet or the foam extruded sheet of the embodiment of the present invention described above. Specifically, the molded product is obtained by, for example, vacuum forming a non-foam extruded sheet or a multilayer body containing the same, or a foam extruded sheet or a multilayer body containing the same. Examples of the molded product include a container such as a tray when a foam extruded sheet or a multilayer body containing the foam extruded sheet is used. When a non-foamed extruded sheet or a multilayer body containing the non-foamed extruded sheet is used, as a molded product, for example, a container for a lunch box lid or a side dish can be produced.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. The resins and extruded sheets in Examples and Comparative Examples were evaluated by the following analysis or measurement method.

(1) Measurement of content of styrene-based monomer and unsaturated carboxylic acid-based monomer in copolymer resin (a) From the integrated ratio of spectra measured by a proton nuclear magnetic resonance ( ¹ H-NMR) measuring machine , The resin composition was quantified.
Sample preparation: The resin pellets 30mg was 4-6 hours heated and dissolved at 60 ° C. in d ₆ -DMSO 0.75ml.
Measuring equipment: JEOL JNM ECA-500
Measurement conditions: measurement temperature 25 ° C., observing nucleus ¹ H, integration number 64 times, repetition time 11 seconds (spectrum assignment of)
The attribution of the spectrum measured in dimethyl sulfoxide deuterated solvent is that the peak of 0.5 to 1.5 ppm is hydrogen of α-methyl group of methacrylic acid, and the peak of 1.6 to 2.1 ppm is methylene group of polymer main chain. Hydrogen, peak at 12.4 ppm is hydrogen of carboxylic acid of methacrylic acid. The peak of 6.5 to 7.5 ppm is hydrogen in the aromatic ring of styrene.

(2) Measurement of Vicat softening temperature According to ISO306, the measurement was performed under the conditions of a load of 50 N and a heating rate of 50 ° C./h.

(3) Measurement of Weight Average Molecular Weight The weight average molecular weight (Mw) of the copolymerized resin (a) was measured by gel permeation chromatography (GPC) under the following conditions and determined in terms of polystyrene.
Equipment: Tosoh HLC-8220
Sorting column: Tosoh TSK gel Super HZM-H
Guard column: Tosoh TSK guard volume Super HZ-H
Measurement solvent: Tetrahydrofuran Sample concentration: Dissolve 5 mg of the measurement sample in 10 mL of solvent Injection amount: 10 μL
Measurement temperature: 40 ° C
Flow velocity: 0.35 mL / min Detection: UV detector 11 types of TSK standard polystyrene manufactured by Tosoh (F-850, F-450, F-128, F-80, F-40, F-20, F-20, F-10, F-4, F-2, F-1, A-5000) were used.

(4) Measurement of melt flow rate Measured according to ISO 1133 (200 ° C., load 49N).

(5) Measurement of Melt Viscosity of Resin Composition The melt viscosity of the resin composition was measured at a resin temperature of 240 ° C. and a shear rate of 400 (1 / s) using a twin capillary rheometer of model RH10 manufactured by Malvern Instruments. ..

(6) Measurement of rubber particle size To measure the rubber particle size, 0.01 g of rubber-modified styrene resin is dissolved in 20 ml of an electrolytic solution (1 mass% ammonium thiocyanate / 99 mass% dimethylformamide solution) and has a diameter of 30 μm. The measurement was performed with a COULTER MULTIZER III (trade name) manufactured by Beckman Coulter Co., Ltd. equipped with an aperture tube. The median diameter of 50% of the volume of the obtained volume-based particle size distribution curve was defined as the rubber particle size.

(7) Measurement of swelling index of toluene insoluble matter and content of toluene insoluble matter Weigh 1 g of rubber-modified styrene resin into a settling tube (W1), add 20 ml of toluene, shake at 23 ° C. for 2 hours, and then centrifuge. Centrifuge with a separator (SS-2050A (rotor: 6B-N6L) manufactured by Sakuma Seisakusho Co., Ltd.) at 4 ° C. or lower and 20000 rpm (centrifugal acceleration 45100 G) for 60 minutes. Gently tilt the settling tube to about 45 degrees and decant the supernatant to remove it. The mass of the insoluble matter containing toluene is precisely weighed (W2), followed by vacuum drying at 160 ° C. and 3 kPa or less for 1 hour, cooled to room temperature in a desiccator, and then the mass of the insoluble toluene is precisely weighed (W2). W3).
The swelling index of toluene insoluble and the toluene insoluble are calculated by the following formulas.
Toluene insoluble swelling index = (W2 / W3)
Toluene insoluble content (mass%) = ((W3) / (W1)) × 100

(8) Measurement of rubber content in resin and [rubber content in toluene insoluble / toluene insoluble] ratio 0.25 g of rubber-modified styrene resin was dissolved in 50 ml of chloroform, and iodine monochloride was added. After reacting the double bond in the rubber component, potassium iodide was added, the remaining iodine monochloride was converted to iodine, and back-distillation was performed with sodium thiosulfate (iodine monochloride method). From the rubber content (W4: mass%) in the rubber-modified styrene resin measured using the iodine monochloride method, the rubber content in the rubber-modified styrene resin (W1) described in (7) above is as follows. Obtained by formula:
Rubber content in toluene insoluble (W5) = W1 x W4 / 100
The mass ratio of toluene insoluble matter to the rubber content in toluene insoluble matter (toluene insoluble matter / rubber content in toluene insoluble matter) was calculated by the following formula:
Toluene insoluble / Rubber content in toluene insoluble = W3 / W5

(9) Measurement of Aliphatic Primary Alcohol Content in Resin Composition 0.5 g of the resin composition is dissolved in 20 ml of methyl ethyl ketone, and the content of the aliphatic primary alcohol is subjected to gas chromatography under the following conditions. Was quantified.
(Measurement condition)
Equipment: Shimadzu Gas Chromatography GC2010
Column: DB-WAX 30m, 0.25mmφ, df = 0.5μm
Temperature: 100 ° C → 5 ° C / min → 130 ° C → 10 ° C / min → 180 ° C-12 minutes →
20 ° C / min → 220 ° C-20 minutes

(10) Measurement of Liquid Paraffin Content in Resin Composition Weigh 2 g of the resin composition, add 40 ml of methyl ethyl ketone, shake at 23 ° C for 40 minutes, add dropwise to 200 ml of methanol, and heat at 60 ° C for 10 minutes. After that, the mixture was cooled to 23 ° C. and filtered through a methanol filter having a hole diameter of 0.45 μm. The filtrate separated by filtration was concentrated by distillation under reduced pressure, dried at 80 ° C. for 30 minutes, cooled to 23 ° C., and dissolved in normal hexane to obtain a 10 ml sample. The content of liquid paraffin was quantified by liquid chromatography under the following conditions for the obtained sample.
(Measurement condition)
Equipment: High Performance Liquid Chromatograph, manufactured by Shimadzu Corporation (trade name) LC-10A
Column: Fully porous silica gel with an average particle diameter of 5 μm, inner diameter 4.6 mm, length 250 mm
Solvent: Normal hexane Temperature: 23 ° C
Solvent flow rate: 2 g / min
Injection volume: 200 μm

(11) Measurement of non-foamed sheet impact strength (kg · cm) A sheet of about 1 mm produced by a 25 mm single-screw sheet extruder is heated at 143 ° C (Vicut softening temperature + 30 ° C) for 10 minutes, and 2 in the sheet extrusion direction. A stretched sheet having a thickness of 0.12 mm was prepared by stretching 8.8 times and 2.8 times in the direction perpendicular to the sheet extrusion, and the impact strength was measured with a film impact tester (A112807502) manufactured by Toyo Seiki Co., Ltd.

(12) Heat resistance evaluation of non-foam extruded sheet Three sheets of 100 mm × 100 mm were cut out from the stretched sheet prepared in (11) and immersed in a bath of silicone oil at 105 ° C. for 30 minutes. The shrinkage rate in the vertical direction and the shrinkage rate in the horizontal direction were measured for the three sheets after immersion, and the average shrinkage rate was calculated from all the shrinkage rates and judged according to the following evaluation criteria. A shrinkage rate of less than 3% is practically preferable.
⊚: Shrinkage rate less than 1% ○: Shrinkage rate 1% or more and less than 3% ×: Shrinkage rate 3% or more

(13) Appearance evaluation of non-foam extruded sheet Three sheets of 150 mm × 150 mm were cut out from the stretched sheet produced in (11), and the average diameter of (major diameter + minor diameter) / 2 was 1 mm or more on the surface of the three sheets. The number of gels, which are foreign substances, was counted, and the appearance was judged from the total number of gels in the three sheets according to the following evaluation criteria.
⊚: Number of gels is 2 points or less ○: Number of gels is 3 to 5 points ×: Number of gels is 6 points or more

(14) Measurement of Impact Strength (kg · cm) of Foam Sheet Using a foam sheet with a thickness of 2.1 mm manufactured by a foam extrusion sheet machine, it was cut into a length of 50 mm and a width of 50 mm, and a film impact tester manufactured by Toyo Seiki Co., Ltd. The impact intensity was measured with (A112807502).

(15) Evaluation of Deep Stretchability of Foam Sheet Using a foam sheet with a thickness of 2.1 mm produced by a foam extrusion sheet machine, the foam sheet is cut into a length of 200 mm and a width of 200 mm, and then the foam sheet is sheeted using a sheet container molding machine. It was sandwiched between fixed frames of a molding machine, the average temperature of the heater was set to the Vicat softening temperature of the resin composition + 105 ° C., and the ambient temperature was set to 140 ° C., and the mixture was heated for 20 seconds. Next, 30 containers having a ratio of the depth (H) to the opening (W) (depth (H) / opening (W)) of 0.6 were formed as the shape of the container. The diameter of the opening is about 85 mm. In this molding, the surface tear that occurs as the deep drawing is performed is evaluated as the deep drawing property. As an evaluation method, the deep drawing property was evaluated in the following three stages by visually observing 30 molded products.
◎: Good (no surface tear)
◯: Less than 5 surface tears ×: 5 or more surface tears

(16) Evaluation of Oil Resistance of Compressed Sheet A non-foamed sheet having a length of 120 mm, a width of 30 mm and a thickness of 1.1 mm was produced by heating at a resin temperature of 200 ° C. for 6 minutes with a compression molding machine. After heating this sheet with a hot air dryer at 80 ° C. for 3 hours, one end of the sheet is fixed by 20 mm in the length direction, 10 mm apart from the fixed position in the length direction, 30 mm in width from the 10 mm position, and 20 mm in the length direction. A cloth soaked in salad oil was attached to the area of, and a load of 250 g was hung on one end of the other sheet, and the breaking time of the sheet was measured at a temperature of 25 ° C. (The sheet is at the position of the cloth soaked in salad oil. Broken). The salad oil used was manufactured by Nisshin Oillio Group Co., Ltd.

Subsequently, a method for producing the copolymerized resin (a) and the rubber-modified styrene resin (b) used in Examples and Comparative Examples will be described.
[Manufacturing method of copolymer resin (a)]
[Resin A1]
A polymerization raw material composition solution consisting of 82.7 parts by mass of styrene, 5.3 parts by mass of methacrylic acid, 12.0 parts by mass of ethylbenzene, and 0.02 parts by mass of 1,1-bis (t-butylperoxy) cyclohexane was prepared. A polymerization apparatus consisting of a completely mixed reactor having a capacity of 4 liters at a rate of 8 liters / hour was then connected to two single-screw extruders in order to remove volatile components such as unreacted monomers and polymerization solvent. It was continuously and sequentially supplied to the volatilization apparatus. The conditions of the polymerization step are the polymerization temperature of the complete mixing reactor 133 to 136 ° C., and the conditions of the first single-screw extruder in the devolatilization step are the temperature of the resin melting zone of 190 to 210 ° C. and the degree of vacuum of 10 kPa, 2. The conditions of the first single-screw extruder were that the temperature of the resin melting zone was 220 to 250 ° C. and the degree of vacuum was 2.5 kPa. The polymer content from the completely mixed reactor was measured by drying the polymerization solution at 215 ° C. and 2.5 kPa for 30 minutes and then measuring [sample mass after drying / sample mass before drying × 100%]. The polymer content was 66% by mass, and the weight average molecular weight of the resin was 217,000 (see Table 1 below).

[Resin A2 to A8]
The conditions were adjusted in the same manner as for the resin A1 so as to have the properties of the resins shown in Table 1 below. The molecular weight of the resin was adjusted by the amount of ethylbenzene as the polymerization solvent, the polymerization temperature, and the like.

[Manufacturing method of rubber-modified styrene resin (b)]
[Resin B1]
A rubber-modified styrene resin is produced by using a polymerization apparatus in which three laminar flow reactors (1.5 liters) equipped with a stirrer are connected in series and then an extruder with a two-stage vent is arranged. 82 parts by mass of styrene, 11 parts by mass of ethylbenzene, 7 parts by mass of Ubepol BR15HB manufactured by Ube Kosan Co., Ltd., and 0.015 parts by mass of 1,1-bis (t-butylperoxy) cyclohexane were put into a raw material tank with a stirrer. Then, the rubber component was dissolved with a stirrer. After that, this raw material solution was supplied to the reactor at a capacity of 0.75 liter / hr, the temperature of the first stage reactor was 110 to 125 ° C, the temperature of the second stage reactor was 125 to 140 ° C, and the first stage. Polymerization was carried out at a temperature of 140 to 155 ° C. in a three-stage reactor. The extruder temperature was 200 to 240 ° C., the degree of vacuum was 2.5 kPa, and the total solid content in the polymer solution discharged from the final reactor was 78% by mass. The rubber particle diameter was adjusted by setting the rotation speed of the stirrer of the first stage laminar flow reactor to 40 rpm (see Table 2 below).

[Resin B2 to B9]
The conditions were adjusted in the same manner as for the resin B1 so as to have the properties of the resins shown in Table 2 below. The rubber particle diameter was adjusted by the rotation speed of the stirrer of the first stage laminar flow reactor. The rotation speeds of the resin B8 and the resin B9 were adjusted to 100 rpm and 30 rpm. The toluene insoluble content was adjusted by adjusting the amount of the polymerization initiator 1,1-bis (t-butylperoxy) cyclohexane, and the resin B5 was adjusted by changing the initiator to 0.04 parts by mass.

Next, Examples and Comparative Examples will be described.
[Example 1]
As shown in Table 3, the copolymer resin (a) is mixed with resin A1 in an proportion of 89% by mass, and the rubber-modified styrene resin (b) is mixed with resin B2 in an proportion of 11% by mass, and further mixed with an isoaliphatic primary alcohol. After adding liquid paraffin, it was extruded with a twin-screw extruder to prepare resin pellets. The isoaliphatic primary alcohol in Table 3 uses a product manufactured by Nissan Chemical Industries, Ltd. (Fineoxocol 180, freezing point: -30 ° C or lower), and the liquid paraffin uses CP-68N manufactured by Idemitsu Kosan Co., Ltd. Using. The isoaliphatic primary alcohol and liquid paraffin contents in Table 3 are measured values with respect to 100 parts by mass of the total mass of the copolymer resin (a) and the rubber-modified styrene resin (b).

Using the obtained resin pellets, a non-foamed extruded sheet and a foamed extruded sheet were prepared, and their physical properties and properties were evaluated. For the non-foamed sheet, a 25 mm single-screw sheet extruder was used to prepare a sheet having a thickness of 1 mm at a temperature of the resin melting zone of 220 to 240 ° C. Using this sheet, it is heated at 143 ° C (Vicat softening temperature + 30 ° C) for 10 minutes, stretched 2.8 times in the sheet extrusion direction and 2.8 times in the sheet extrusion perpendicular direction, and stretched to a thickness of 0.12 mm. A sheet was prepared. As for the foamed sheet, a resin composition was obtained by adding 0.2 parts by mass of talc (average particle diameter 1.5 μm) as a foaming nucleating agent and 4.5 parts by mass of liquefied butane as a foaming agent. A foam sheet was produced using a foam extruder equipped with a circular die having a diameter of 150 mm. The temperature of the resin melting zone of the foam sheet extruder was adjusted to 220 to 250 ° C., the temperature of the rotary cooler was adjusted to 150 to 190 ° C., and the temperature of the die was adjusted to 160 to 175 ° C. The foam immediately after extrusion foaming was cooled with a cooling mandrel and cut with a cutter at one point on the circumference to prepare a foamed sheet having a sheet thickness of 2.1 mm, a width of 1000 mm, and a foaming ratio of about 10 times. As for the compression sheet, a sheet having a length of 120 mm, a width of 30 mm, and a thickness of 1.1 mm was produced by heating at a resin temperature of 200 ° C. for 6 minutes with a compression molding machine.
Table 3 shows the evaluation results of the physical properties and properties of the obtained non-foamed sheet, foamed sheet and compressed sheet, respectively.

[Examples 2 to 9]
The copolymer resin (a) and the rubber-modified styrene resin (b) are mixed at the ratio shown in Table 3, and the isoaliphatic primary alcohol and liquid paraffin are further mixed, and the non-foamed sheet is similarly mixed with Example 1. , Foam sheet and compression sheet were prepared. Table 3 shows the evaluation results of the physical properties and properties of the obtained non-foamed sheet, foamed sheet and compressed sheet, respectively. Only in Example 6, the isoaliphatic primary alcohol was not added. Moreover, liquid paraffin was not added only in Example 9.

[Comparative Example 1]
In Example 4, the resin A2 was mixed in an proportion of 85% by mass as the copolymer resin (a) and the resin B3 as the rubber-modified styrene resin (b) in a proportion of 15% by mass, whereas in Comparative Example 1, the copolymer resin was mixed. Resin A2 was changed to 95% by mass as (a), and resin B3 was changed to 5% by mass as rubber-modified styrene resin (b) and mixed. The remaining items were carried out in the same manner as in Example 4, and non-foamed sheets, foamed sheets and compressed sheets were prepared. Table 3 shows the evaluation results of the physical properties and properties of the obtained non-foamed sheet, foamed sheet and compressed sheet.
In Comparative Example 1, the amount of the resin B3 added to the rubber-modified styrene resin (b) was as small as 5% by mass, and the impact strength and deep drawing property of the non-foamed sheet and the foamed sheet were higher than those of Example 4. It became inferior.

[Comparative Example 2]
In Example 4, the resin A2 was mixed in a proportion of 85% by mass as the copolymer resin (a) and the resin B3 as the rubber-modified styrene resin (b) in a proportion of 15% by mass, whereas in Comparative Example 2, the copolymer resin was mixed. Resin A2 was changed to 74% by mass as (a), and resin B3 was changed to 26% by mass as rubber-modified styrene resin (b) and mixed. The remaining items were carried out in the same manner as in Example 4, and non-foamed sheets, foamed sheets and compressed sheets were prepared. Table 3 shows the evaluation results of the physical properties and properties of the obtained non-foamed sheet, foamed sheet and compressed sheet.
In Comparative Example 2, the amount of the resin B3 added to the rubber-modified styrene resin (b) was as large as 26% by mass, the Vicat softening temperature was lower than that of Example 4, and the heat resistance of the non-foamed sheet was inferior. It became.

[Comparative Example 3]
In Example 4, the resin A2 was mixed in an proportion of 85% by mass as the copolymer resin (a) and the resin B3 as the rubber-modified styrene resin (b) in a proportion of 15% by mass, whereas in Comparative Example 3, the copolymer resin was mixed. Resin A2 was changed to 95% by mass as (a), and resin B6 was changed to 5% by mass as rubber-modified styrene resin (b) and mixed. The remaining items were carried out in the same manner as in Example 4, and non-foamed sheets, foamed sheets and compressed sheets were prepared. Table 3 shows the evaluation results of the physical properties and properties of the obtained non-foamed sheet, foamed sheet and compressed sheet.
In Comparative Example 3, the amount of the resin B6 added to the rubber-modified styrene resin (b) was as small as 5% by mass, and the impact strength and deep drawability of the non-foamed sheet and the foamed sheet were improved as compared with Example 4. It became inferior.

[Comparative Example 4]
In Example 3, resin A2 was mixed at a ratio of 85% by mass as the copolymer resin (a) and resin B2 was mixed as the rubber-modified styrene resin (b) at a ratio of 15% by mass, whereas in Comparative Example 4, the copolymer resin was mixed. Resin A6 was changed to 85% by mass as (a), and resin B2 was changed to 15% by mass as the rubber-modified styrene resin (b) and mixed. The remaining items were carried out in the same manner as in Example 3 to prepare non-foamed sheets, foamed sheets and compressed sheets. Table 3 shows the evaluation results of the physical properties and properties of the obtained non-foamed sheet, foamed sheet and compressed sheet.
In Comparative Example 4, the methacrylic acid content of the resin A6 used in the copolymer resin (a) was as small as 4.8% by mass, the Vicat softening temperature was lower than in Example 3, and the heat resistance of the non-foamed sheet was low. Became inferior.

[Comparative Example 5]
In Example 1, resin A1 was mixed in a proportion of 89% by mass as the copolymer resin (a), and resin B2 was mixed as a rubber-modified styrene resin (b) in a proportion of 11% by mass, whereas in Comparative Example 5, the copolymer resin was mixed. Resin A7 was changed to 89% by mass as (a), and resin B2 was changed to 11% by mass as rubber-modified styrene resin (b) and mixed. The remaining items were carried out in the same manner as in Example 1 to prepare non-foamed sheets, foamed sheets and compressed sheets. Table 3 shows the evaluation results of the physical properties and properties of the obtained non-foamed sheet, foamed sheet and compressed sheet.
In Comparative Example 5, the weight average molecular weight of the resin A7 used for the copolymer resin (a) was as high as 292,000, and the appearance of the non-foamed sheet and the deep drawing property of the foamed sheet were inferior to those of Example 1. It became a thing.

[Comparative Example 6]
In Example 2, the resin A2 was mixed in a proportion of 88% by mass as the copolymer resin (a), and the resin B2 was mixed in a proportion of 12% by mass as the rubber-modified styrene resin (b), whereas in Comparative Example 6, the copolymer resin was mixed. Resin A8 was changed to 88% by mass as (a), and resin B2 was changed to 12% by mass as rubber-modified styrene resin (b) and mixed. The remaining items were carried out in the same manner as in Example 2 to prepare non-foamed sheets, foamed sheets and compressed sheets. Table 3 shows the evaluation results of the physical properties and properties of the obtained non-foamed sheet, foamed sheet and compressed sheet.
In Comparative Example 6, the content of the methacrylic acid monomer of the resin A8 used in the polymerized resin (a) was as high as 15.3% by mass, and the impact strength of the non-foamed sheet and the foamed sheet was higher than that of Example 2. The appearance of the non-foamed sheet and the deep drawing property of the foamed sheet were inferior.

[Comparative Example 7]
In Example 2, resin A2 was mixed in a proportion of 88% by mass as the copolymer resin (a), and resin B2 was mixed in a proportion of 12% by mass as the rubber-modified styrene resin (b), whereas in Comparative Example 7, the copolymer resin was mixed. Resin A2 was changed to 88% by mass as (a), and resin B7 was changed to 12% by mass as rubber-modified styrene resin (b) and mixed. The remaining items were carried out in the same manner as in Example 2 to prepare non-foamed sheets, foamed sheets and compressed sheets. Table 3 shows the evaluation results of the physical properties and properties of the obtained non-foamed sheet, foamed sheet and compressed sheet.
In Comparative Example 7, the rubber content of the resin B7 used for the rubber-modified styrene resin (b) was as small as 5.9% by mass, and the impact strength of the non-foamed sheet and the foamed sheet and the foamed sheet were compared with those of Example 2. The deep drawing property of was inferior.

[Comparative Example 8]
In Example 2, resin A2 was mixed in a proportion of 88% by mass as the copolymer resin (a), and resin B2 was mixed as a rubber-modified styrene resin (b) in a proportion of 12% by mass, whereas in Comparative Example 8, the copolymer resin was mixed. Resin A2 was changed to 88% by mass as (a), and resin B8 was changed to 12% by mass as rubber-modified styrene resin (b) and mixed. The remaining items were carried out in the same manner as in Example 2 to prepare non-foamed sheets, foamed sheets and compressed sheets. Table 3 shows the evaluation results of the physical properties and properties of the obtained non-foamed sheet, foamed sheet and compressed sheet.
In Comparative Example 8, the rubber particle diameter of the resin B8 used for the rubber-modified styrene resin (b) was as small as 2.1 μm, and the impact strength of the non-foamed sheet and the foamed sheet and the oil resistance of the compressed sheet were compared with those of Example 2. The sex became inferior.

[Comparative Example 9]
In Example 2, the resin A2 was mixed in a proportion of 88% by mass as the copolymer resin (a), and the resin B2 was mixed in a proportion of 12% by mass as the rubber-modified styrene resin (b), whereas in Comparative Example 9, the copolymer resin was mixed. Resin A2 was changed to 88% by mass as (a), and resin B9 was changed to 12% by mass as rubber-modified styrene resin (b) and mixed. The remaining items were carried out in the same manner as in Example 2 to prepare non-foamed sheets, foamed sheets and compressed sheets. Table 3 shows the properties and evaluation results of the obtained non-foamed sheet, foamed sheet and compressed sheet.
In Comparative Example 9, the rubber particle diameter of the resin B9 used for the rubber-modified styrene resin (b) was as large as 6.2 μm, and the impact strength of the non-foamed sheet and the foamed sheet and that of the non-foamed sheet were higher than those of Example 2. The appearance was inferior.

The heat-resistant styrene resin composition of the present invention is excellent in moldability such as heat resistance, mechanical strength, appearance, oil resistance, and deep drawing, and is therefore suitable for the production of foamed and non-foamed sheets and the secondary molding process thereof. , The obtained molded product can be suitably used for applications such as food packaging materials.

Claims (9)

A heat-resistant styrene-based resin composition containing a copolymer resin (a) containing a styrene-based monomer unit and an unsaturated carboxylic acid-based monomer unit, and a rubber-modified styrene-based resin (b).
When the total content of the copolymer resin (a) and the rubber-modified styrene resin (b) is 100% by mass, the content of the copolymer resin (a) is 80 to 91% by mass. The content of the rubber-modified styrene resin (b) is 9 to 20% by mass.
The copolymerized resin (a) contains the styrene-based monomer unit when the total content of the styrene-based monomer unit and the unsaturated carboxylic acid-based monomer unit is 100% by mass. Is 86 to 94% by mass, the content of the unsaturated carboxylic acid-based monomer unit is 6 to 14% by mass, and the weight average molecular weight is 150,000 to 240,000.
The rubber-modified styrene resin (b) has a rubber content of 8 to 15% by mass and a rubber particle diameter of 2 when the total mass of the rubber-modified styrene resin (b) is 100% by mass. A heat-resistant styrene-based resin composition having a thickness of 7.7 to 5.3 μm. The ratio of the melt viscosity of the rubber-modified styrene resin (b) to the melt viscosity of the copolymer resin (a) when the melt temperature of the resin is 240 ° C. and the shear rate is 400 (1 / s) (resin (resin (resin)). The heat-resistant styrene resin composition according to claim 1, wherein b) / resin (a)) is 0.6 to 1.4. The swelling index of the toluene-insoluble matter of the rubber-modified styrene resin (b) is 8 to 15, and the mass ratio of the toluene-insoluble matter to the rubber content in the toluene-insoluble matter (toluene-insoluble matter / toluene-insoluble matter). The heat-resistant styrene resin composition according to claim 1 or 2, wherein the rubber content) is 2.0 to 3.4. The heat-resistant styrene-based resin composition according to any one of claims 1 to 3, wherein the bicut softening temperature of the heat-resistant styrene-based resin composition is 109 ° C. or higher. A fat having a freezing point of −10 ° C. or lower and a carbon number of 14 or more when the total content of the copolymerized resin (a) and the rubber-modified styrene resin (b) is 100 parts by mass. The heat-resistant styrene resin composition according to any one of claims 1 to 4, which contains 0.01 to 1.0 parts by mass of a group primary alcohol. Claims 1 to 1.0, when the total content of the copolymerized resin (a) and the rubber-modified styrene resin (b) is 100 parts by mass, the plasticizer is contained in an amount of 0.01 to 1.0 parts by mass. The heat-resistant styrene resin composition according to any one of 5. A non-foamed extruded sheet formed by using the heat-resistant styrene resin composition according to any one of claims 1 to 6. A foam extruded sheet formed by using the heat-resistant styrene resin composition according to any one of claims 1 to 6. A molded product formed by using the non-foam extruded sheet according to claim 7 or the foam extruded sheet according to claim 8.