TW201527067A - Extrude foam body and container - Google Patents

Abstract

The present extrude foam body comprises a linear vinyl aromatic copolymer (A) and a branched vinyl aromatic copolymer (B) in which a conjugated diene part in the block copolymer constituted by a vinyl aromatic hydrocarbons and a conjugated diene are bonded with a vinyl aromatic hydrocarbon chain. In addition, in the present extrude foam body comprises, the (A) and (B) comprises specific components. Moreover, the present extrude foam body are constructed so as to satisfy specific condition.

Description

Extruded foam and container

This invention relates to extruded foams and containers.

The styrene-based resin is widely used as a molding material for home appliances, office products, toys, and miscellaneous materials because of its excellent transparency, moldability, and rigidity. Moreover, due to its excellent elongation and foaming properties, it is often used. Mainly used in food packaging materials such as foam trays (PSP). Further, since it has excellent heat resistance and mechanical strength, it is also widely used for the use of a plate-like extruded foam such as a heat-resistant material or an overlapping core material.

In the method for producing an extruded foam formed of a styrene resin composition, although various methods have been known from the prior art, in general, it is commonly used in an extrusion machine in a styrene resin. After the foaming agent is added and melted and kneaded, the foaming composition formed by the melt kneaded product is extruded from an extruder under a low pressure atmosphere to obtain a foam.

A simple container for foods which is formed by extrusion of a foamed sheet of a polystyrene resin and is formed by thermoforming, for example, is widely used for various foods such as meat, fish, and deli garnishes, and various foods such as instant noodles and natto containers. container. In such a simple container obtained by thermoforming of the foamed sheet, in order to reduce the cost, it is attempted to increase the ratio of the container. However, if the container is doubled When the rate is increased, the strength of the product is reduced, and the container is prone to cracking or the like when the plate is wrapped. Similarly, in the plate-like extruded foam, in order to reduce the cost, it is attempted to increase the magnification. However, if the density of the foam is to be lowered to increase the magnification, the foamed cells cannot be formed well, and formation may occur. The foaming cells are joined, that is, the problem of the independent bubble rate of the so-called continuous bubble and the reduction of the strength of the product, and the appearance of roughening.

In order to solve this problem, it is possible to control the shape of the foamed cell during extrusion foaming, and to increase the thickness of the vacuum-formed container (especially the thickness of the easily breakable portion) so as to maintain the strength of the container even if it is high-magnification. (For example, refer to Non-Patent Document 1). Further, a method of using a styrene resin having a specific number of branches as a material for a container has been proposed (for example, refer to Patent Document 1). On the other hand, a styrene-based resin having a specific Z average molecular weight and a ratio Mw/Mn of a weight average molecular weight Mw to a number average molecular weight Mn is specified (for example, refer to Patent Document 2) and a Z average molecular weight is used. A method (for example, see Patent Document 3) in which the ratio (Mz/Mw) of Mz to the weight average molecular weight Mw is a specific value or more.

[Advanced technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2003-49033

[Patent Document 2] Japanese Patent Laid-Open No. Hei 10-182870

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2005-335373

[Non-patent literature]

[Non-Patent Document 1] Nikkei Ecology / October 2005 issue, pages 38 to 39

However, the technique described in Non-Patent Document 1 is improved by the molding processing technique and the shape of the container, and the strength of the container is not improved by the improvement of the styrene resin. Further, in Patent Document 1, although the styrene resin is improved, the magnification of the extruded foam sheet is as low as five times, and there is no problem in that the strength of the product is lowered when the container is increased in magnification by the material surface. That is, there is still a need for materials that are suitable for further high magnification. Further, in the technique described in Patent Document 2, since a high molecular weight body having a number average molecular weight Mn of 18 to 21 is used, molding processing may be difficult under certain conditions. Further, in the technique described in Patent Document 3, since the strength of the foam is ignored, it is not possible to obtain a high-magnification foam having a sufficiently good closed cell ratio and foam strength.

The present invention has been made in view of the problems of the prior art described above, and provides excellent foamability while maintaining a high closed cell ratio even at a high rate, exhibiting excellent mechanical properties and excellent moldability. An extruded foam having a balance between density and product strength is intended. Further, it is an object of the present invention to provide a container obtained from the above-mentioned extruded foam.

The inventors of this case have worked hard to concentrate on the status quo. As a result of the research, it has been found that an extruded foam containing a vinyl aromatic hydrocarbon polymer composition in which a branched structure is introduced by using a specific branched polymer and polymerized in a molecule can solve the above problems, thereby completing the present invention. .

That is, the present invention is as set forth below.

[1] An extruded foam comprising a vinyl aromatic hydrocarbon polymer composition comprising a linear vinyl aromatic hydrocarbon polymer (A) and a vinyl aromatic hydrocarbon and a conjugated diene a branched vinyl aromatic hydrocarbon polymer (B) having a vinyl aromatic hydrocarbon chain bonded to a conjugated diene portion of the segment copolymer, wherein the above (A) and (B) contain one type of ethylene selected as the free a homopolymer of a polyaromatic hydrocarbon or a copolymer of two or more vinyl aromatic hydrocarbons, a copolymer of a vinyl aromatic hydrocarbon and an unsaturated carboxylic acid, a vinyl aromatic hydrocarbon and an unsaturated carboxylic acid, and/or no a copolymer of an alkyl ester of a saturated carboxylic acid, and at least one of a group of a copolymer of a vinyl aromatic hydrocarbon and an unsaturated carboxylic anhydride or maleimide, and containing the following ( a vinyl aromatic hydrocarbon polymer composition of a) to (c): (a) the above (B) is branched starting from a conjugated diene compound unit in the aforementioned block copolymer; (b) the above ethylene In the aromatic aromatic polymer composition, the content of the block copolymer is 0.1% by mass or more based on the amount of the conjugated diene. (c) The above-mentioned vinyl aromatic hydrocarbon polymer composition is supplied to the Z average molecular weight before oxidative decomposition when oxidized and decomposed with tetrabutyl hydride as a catalyst using ruthenium tetroxide as a catalyst ( Mz1) and the oxidation The ratio (Mz2/Mz1) of the Z average molecular weight (Mz2) after the solution is 0.30 or more and 0.90 or less.

[2] The extruded foam according to [1], wherein in the vinyl aromatic hydrocarbon polymer composition, the above (B) is dispersed in the above (A), and is enlarged by 100,000 times. In the electron micrograph, there are 0 to 1000 point particles having a particle diameter of 50 nm or less per 4 μm ² area.

[3] The extruded foam according to [1] or [2] wherein the vinyl aromatic hydrocarbon polymer composition has an extensional viscosity of 10 at 200 ° C, 2500 Pa sec. 10,000 Pa sec or more and 1 million Pa ‧ sec or less, the extruded foam described above.

[4] The extruded foam according to any one of [1] to [3] wherein the vinyl average hydrocarbon molecular composition has a Z average molecular weight (Mz) and a weight average molecular weight (Mw). The ratio (Mz/Mw) is 2.0 or more and 4.0 or less.

[5] The extruded foam according to any one of [1] to [4] wherein the vinyl aromatic hydrocarbon polymer composition has a degree of branching of 0.30 or more and less than 0.90.

[6] The extruded foam according to any one of [1] to [5] wherein, in the vinyl aromatic hydrocarbon polymer composition, more than 1,000,000 The molecular weight component is 2.0% or more and 20% or less.

[7] The extruded foam according to any one of [1] to [6] wherein the amount of the constituent component derived from the conjugated diene in the block copolymer is 5% by mass or more and 40% by mass. In the block copolymer, the amount of the component derived from the vinyl aromatic hydrocarbon is 60% by mass or more and 95% by mass or less, and the amount of the vinyl bond in the block copolymer is 7% or more and 70% or less.

[8] A container obtained by vacuum molding an extruded foam according to any one of [1] to [7].

The extruded foam of the present invention can maintain a high closed cell ratio even at a high rate, exhibit excellent mechanical properties and excellent formability, and has excellent balance between foam density and product strength.

Fig. 1 is a view showing a method of measuring the strength of the web of the foamed disk.

Fig. 2 is a graph showing the relationship between the melt flow rate (MFR) and the elongational viscosity by comparison of the examples and the comparative examples.

Fig. 3 is a graph showing the relationship between the strength of the web and the deep drawing formability by comparison of the examples and the comparative examples.

Figure 4 shows the foam density by comparison of the examples and the comparative examples. A graph of the relationship between compression strength.

Hereinafter, the form for carrying out the present invention (hereinafter also referred to as "this embodiment") will be described in detail. The present invention is not limited to the embodiment, and various modifications can be made without departing from the spirit and scope of the invention.

<extruded foam>

The extruded foamed sheet of the present embodiment contains a conjugated diene portion comprising a linear vinyl aromatic hydrocarbon polymer (A) and a block copolymer of a vinyl aromatic hydrocarbon and a conjugated diene. A vinyl aromatic hydrocarbon polymer composition in which a branched vinyl aromatic hydrocarbon polymer (B) having a vinyl aromatic hydrocarbon chain is bonded to the middle. In addition, in the present specification, the linear vinyl aromatic hydrocarbon polymer in the above-described embodiment may be simply referred to as "(A)", and the branched vinyl group in the above embodiment may be used. The aromatic hydrocarbon polymer is only referred to as "(B)".

In the present embodiment, the above (A) and (B) contain a homopolymer selected from one type of vinyl aromatic hydrocarbon or a copolymer of two or more kinds of vinyl aromatic hydrocarbons, a vinyl aromatic hydrocarbon, and a copolymer of a saturated carboxylic acid, a copolymer of a vinyl aromatic hydrocarbon with an unsaturated carboxylic acid and/or an alkyl ester of an unsaturated carboxylic acid, and a vinyl aromatic hydrocarbon with an unsaturated carboxylic anhydride or maleicylene At least one of the groups of amine copolymers.

Furthermore, in the present embodiment, the vinyl aromatic hydrocarbon polymer composition satisfies the following (a) to (c): (a) the above (B) is a conjugated one of the block copolymers The olefinic compound unit branches as a starting point; (b) The content of the block copolymer in the vinyl aromatic hydrocarbon polymer composition is 0.1% by mass or more and 2.0% by mass or less based on the amount of the conjugated diene; (c) the aforementioned vinyl aromatic The hydrocarbon polymer composition is supplied to the Z-average molecular weight (Mz1) before the oxidative decomposition and the Z average molecular weight after the oxidative decomposition when the oxidative decomposition is carried out with ruthenium tetroxide as a catalyst. The ratio of Mz2) (Mz2/Mz1) is 0.30 or more and 0.90 or less.

According to the above-described configuration, the extruded foam of the present embodiment can maintain a high closed cell ratio even at a high rate, exhibit excellent mechanical properties and excellent formability, and has excellent foam density and The balance between product strength.

In the present embodiment, the "block copolymer-containing" means that the component (B) derived from the block copolymer is contained in the vinyl aromatic hydrocarbon polymer composition of the present embodiment. In addition, "(A) and (B) contain a homopolymer selected from one type of vinyl aromatic hydrocarbon or a copolymer of two or more kinds of vinyl aromatic hydrocarbons, a vinyl aromatic hydrocarbon and an unsaturated carboxylic acid. a copolymer of a copolymer, a vinyl aromatic hydrocarbon and an unsaturated carboxylic acid and/or an alkyl ester of an unsaturated carboxylic acid, and a copolymer of a vinyl aromatic hydrocarbon with an unsaturated carboxylic anhydride or maleimide "At least one of the group of substances" means that, in the component (A), "a homopolymer of one type of vinyl aromatic hydrocarbon or a copolymer of two or more kinds of vinyl aromatic hydrocarbons or a vinyl group" is selected. a copolymer of an aromatic hydrocarbon and an unsaturated carboxylic acid, a copolymer of a vinyl aromatic hydrocarbon with an unsaturated carboxylic acid and/or an alkyl ester of an unsaturated carboxylic acid, and a vinyl aromatic hydrocarbon At least one of the group of the copolymer of the unsaturated carboxylic anhydride or the maleimide is included in the vinyl aromatic hydrocarbon polymer composition of the present embodiment as the component (A) itself. In the component (B), a copolymer obtained by selecting one free vinyl aromatic hydrocarbon or a copolymer of two or more vinyl aromatic hydrocarbons, a copolymer of a vinyl aromatic hydrocarbon and an unsaturated carboxylic acid a copolymer of a vinyl aromatic hydrocarbon and an unsaturated carboxylic acid and/or an alkyl ester of an unsaturated carboxylic acid, and a copolymer of a vinyl aromatic hydrocarbon and an unsaturated carboxylic anhydride or maleimide. At least one of the components of the group is contained in a vinyl aromatic hydrocarbon chain bonded to the conjugated diene portion of the above block copolymer.

In the vinyl aromatic hydrocarbon polymer composition, a branched vinyl aromatic hydrocarbon polymer (B) represented by a branched polymer is used, and a branched structure is introduced into the molecule to be polymerized. By applying the vinyl aromatic hydrocarbon polymer composition desired in the present embodiment, the extruded foam of the present embodiment is easy to impart molecular alignment when the foamed cells are stretched, and is increased in strength. The deep drawing container is excellent in secondary formability. Further, since a foamed container having excellent product strength can be obtained even at a high expansion ratio, it is possible to contribute to cost reduction of the product. In addition, the extruded foam of the present embodiment is not limited to the following. However, a plate-like extruded foam, an extruded foamed sheet, and a container obtained by the above are typically used.

(vinyl aromatic hydrocarbon polymer composition)

In the present embodiment, the component (B) contained in the vinyl aromatic hydrocarbon polymer composition is a conjugated diene compound in the above block copolymer. The unit branches as a starting point.

In the present embodiment, the content of the block copolymer in the vinyl aromatic hydrocarbon polymer composition is 0.1% by mass or more and 2.0% by mass or less based on the amount of the conjugated diene. Since the amount of the conjugated diene is within the above range, it can be an extruded foam excellent in both moldability and mechanical properties after container molding. The amount of the conjugated diene is preferably 0.2% by mass or more, more preferably 0.3% by mass or more, and still more preferably 0.4% by mass or more from the viewpoint of elongational viscosity. On the other hand, from the viewpoint of fluidity, it is preferably 1.5% by mass or less, and more preferably 1.3% by mass or less. When the amount of the conjugated diene is less than 0.1% by mass, the probability of bonding of the vinyl aromatic hydrocarbon chain in the conjugated diene portion becomes low, and the branched vinyl aromatic hydrocarbon polymer which cannot be obtained by high molecular weight cannot be obtained. (B), a composition having a high stretch viscosity could not be obtained. Therefore, an extruded foam excellent in both moldability and mechanical properties after container formation cannot be obtained. In addition, when the amount of the conjugated diene is more than 2% by mass, the processability (fluidity) and rigidity of the vinyl aromatic hydrocarbon polymer composition are reduced, so that both the moldability and the mechanical properties after the container formation cannot be obtained. Extruded foam. Further, the amount of the conjugated diene in terms of conversion can be measured by the method described in the examples below.

The component (A) in the present embodiment may contain a radically polymerizable monomer as a constituent unit. The radically polymerizable monomer is not limited to the following, and examples thereof include a vinyl aromatic hydrocarbon monomer. Further, an unsaturated carboxylic acid, an alkyl ester of an unsaturated carboxylic acid, an unsaturated carboxylic anhydride, maleimide or the like may be used in combination with the above vinyl aromatic hydrocarbon monomer.

Preferably, the above-mentioned radically polymerizable monomer is used to obtain a copolymer containing a single vinyl aromatic hydrocarbon or a copolymer of two or more vinyl aromatic hydrocarbons, a vinyl aromatic hydrocarbon, and a copolymer of an unsaturated carboxylic acid, a copolymer of a vinyl aromatic hydrocarbon with an unsaturated carboxylic acid and/or an alkyl ester of an unsaturated carboxylic acid, and a vinyl aromatic hydrocarbon with an unsaturated carboxylic anhydride or maleic acid A polymer of at least one of the groups of copolymers of imines. In other words, the vinyl aromatic hydrocarbon polymer composition of the present embodiment preferably contains a copolymer containing a homopolymer selected from one type of vinyl aromatic hydrocarbon or a copolymer of two or more kinds of vinyl aromatic hydrocarbons, and a vinyl group. a copolymer of an aromatic hydrocarbon and an unsaturated carboxylic acid, a copolymer of a vinyl aromatic hydrocarbon and an unsaturated carboxylic acid and/or an alkyl ester of an unsaturated carboxylic acid, and a vinyl aromatic hydrocarbon and an unsaturated carboxylic anhydride or a cis At least one polymer of the copolymer of butenimide is a component (A) and a component (B). Further, the copolymer of the above vinyl aromatic hydrocarbon and the unsaturated carboxylic acid and/or the alkyl ester of the unsaturated carboxylic acid may be a binary polymer or a terpolymer.

The above vinyl aromatic hydrocarbon monomer is not limited to the following, however, for example, styrene, α-methylstyrene, o-, m-, and p-methylstyrene, ethylstyrene, and C may be used. Styrene, butyl styrene, chlorostyrene, dichlorostyrene, bromostyrene, dibromostyrene, and the like. Among them, styrene is preferred. The vinyl aromatic hydrocarbon monomer may be used alone or in combination of two or more.

Specific examples of other unsaturated monomers which can be used in combination (copolymerizable) with a vinyl aromatic hydrocarbon monomer are shown below as being within the scope of the object of the present embodiment. That is, the above unsaturated carboxylic acid is not The following are limited, and examples thereof include acrylic acid, methacrylic acid, maleic acid, and the like. Further, the alkyl ester of the above unsaturated carboxylic acid is not limited to the following, and examples thereof include an alkyl acrylate such as methyl acrylate, ethyl acrylate, butyl acrylate or 2-ethylhexyl acrylate. An alkyl ester of methacrylic acid such as methyl acrylate, ethyl methacrylate, butyl methacrylate or cyclohexyl methacrylate. In addition, the unsaturated carboxylic acid anhydride is not limited to the following, and examples thereof include maleic anhydride and the like. Further, the maleimide is not limited to the following, and examples thereof include N-methyl maleimide and N-phenyl maleimide. The vinyl aromatic hydrocarbon polymer composition of the present embodiment preferably contains 50% by mass or less of the above-mentioned vinyl aromatic hydrocarbon monomer and a copolymerizable unsaturated monomer. More specifically, the amount of the unsaturated carboxylic acid to be used is preferably from 0 to 30% by mass, more preferably from 1 to 20% by mass. The amount of the alkyl ester of the above unsaturated carboxylic acid is preferably from 0 to 45% by mass, more preferably from 1 to 40% by mass. The amount of the unsaturated carboxylic acid anhydride and the above-mentioned maleimide is preferably from 0 to 30% by mass, more preferably from 1 to 20% by mass. When the above-mentioned vinyl aromatic hydrocarbon monomer and the copolymerizable unsaturated monomer are 50% by mass or less, sufficient heat resistance and moldability tend to be ensured.

Further, in the present embodiment, the branched vinyl aromatic hydrocarbon polymer (B) in the vinyl aromatic hydrocarbon polymer composition can be, for example, a perylene tetroxide solution and a hydrogen peroxide tert-butyl group. The mixed decomposer oxidatively decomposes the conjugated diene block in the molecule to confirm its existence. That is, if a branched vinyl aromatic hydrocarbon polymer (B) is formed, Then, the vinyl aromatic hydrocarbon chain bonded in the conjugated diene portion of the block copolymer of the vinyl aromatic hydrocarbon and the conjugated diene is cleaved by oxidative decomposition, so that the Z average molecular weight is lowered. In the present embodiment, the ratio (Mz2/Mz1) of the Z average molecular weight (Mz1) before the oxidative decomposition of the vinyl aromatic hydrocarbon polymer composition to the Z average molecular weight (Mz2) after the oxidative decomposition is 0.30 or more and 0.90. the following. When the ratio of the Z average molecular weight is within the above range, an extruded foam excellent in both moldability and mechanical properties after container formation can be formed. The ratio of the Z average molecular weight is 0.30 or more, preferably 0.40 or more, and more preferably 0.45 or more from the viewpoint of fluidity. On the other hand, from the viewpoint of elongational viscosity, it is 0.90 or less, preferably 0.85 or less, more preferably 0.80 or less. When the ratio of the average molecular weight of Z exceeds 0.90, the bonding of the vinyl aromatic hydrocarbon chain to the conjugated diene portion is small, the polymer cannot be obtained, and a composition having a high elongation viscosity cannot be obtained, so that moldability and container formation cannot be obtained. The extruded foam is excellent in both mechanical properties. Further, when the ratio of the average molecular weight of Z is less than 0.3, the formability is deteriorated. Further, the ratio of the above Z average molecular weight can be measured by the method described in the examples below.

In the present embodiment, the vinyl aromatic hydrocarbon polymer composition has a melt flow rate (MFR) at 200 ° C and a load of 49 N, and is excellent in terms of both moldability and mechanical properties after container formation. The foam is preferably 0.5 g/10 min or more. The preferred MFR range varies depending on the application. However, for example, in the case of an extruded foam having a thickness of 0.5 mm to 5.0 mm, a preferred MFR range is 0.8 g/10 minutes or more and 5.0 g from the same viewpoint as described above. Below /10 minutes, the range of better MFR is 1.0g/10 minutes More than 4.0g/10 minutes below the clock. When the MFR is 0.5 g/10 minutes or more, not only the amount of discharge at the time of extrusion can be sufficiently ensured, but also the appearance of the extruded foam obtained by using the vinyl aromatic hydrocarbon polymer composition tends to be good. Further, when the MFR is 6.0 g/10 minutes or less, the strength of the foamed container which is secondary molded by using the extruded foam can be prevented from being lowered, and the product tends to have high productivity and strength. On the other hand, in the case of an extruded foam having a thickness of 5 mm or more and 100 mm or less, from the same viewpoint as described above, the MFR is preferably in the range of 0.8 g/10 min or more and 9.5 g/10 min or less, and a more preferable MFR range. It is 1.0 g/10 minutes or more and 9.0 g/10 minutes or less. When the MFR is 0.5 g/10 minutes or more, in the case where the discharge amount is reduced as described above, even if the temperature of the extruder is increased in order to increase the discharge amount, there is a tendency that the decomposition of the flame retardant or the like is prevented. Further, when the MFR is 10.0 g/10 minutes or less, the closed cell ratio of the extruded foam and the strength of the product can be prevented from being lowered, and the product tends to have high rate and strength. Further, the above MFR may be a value measured at 200 ° C and 49 N in accordance with JIS K 7210.

In the present embodiment, the ratio (Mz/Mw) of the Z average molecular weight (Mz) to the weight average molecular weight (Mw) in the vinyl aromatic hydrocarbon polymer composition is preferably 2.0 or more and 4.0 or less. When the above (Mz/Mw) is 2.0 or more, a vinyl aromatic hydrocarbon polymer composition having a sufficiently high tensile viscosity tends to be obtained, and the tendency of the product strength to be lowered can be effectively prevented. Further, when the above (Mz/Mw) is 4.0 or less, it is easy to control the high molecular weight component in the vinyl aromatic hydrocarbon polymer composition to an appropriate amount, and it is possible to obtain a better extrusion shape and obtain a good shape. Extrusion The tendency of the bubble. Further, the above (Mz/Mw) can be measured by gel permeation chromatography (GPC).

In the present embodiment, the vinyl aromatic hydrocarbon polymer composition is as described above, and is composed of a linear vinyl aromatic hydrocarbon polymer (A) and a vinyl aromatic hydrocarbon and a conjugated diene. The branched conjugated diene portion of the segment copolymer has a branched vinyl aromatic hydrocarbon polymer (B) bonded to a vinyl aromatic hydrocarbon chain, so that it is linear compared to the conventional vinyl aromatic hydrocarbon monomer. A polymer, a high molecular weight polymer can be easily obtained. The molecular weight component of 1,000,000 or more of the vinyl aromatic hydrocarbon polymer composition is preferably 2.0% or more and 20% or less, more preferably 3.0% or more and 18% or less, still more preferably 4.0% or more and 15% or less. When the molecular weight component of 1,000,000 or more is 2.0% or more, the amount of the high molecular weight component can be sufficient, and when compared with the same weight average molecular weight, linear polymerization having a higher molecular weight than the conventional vinyl aromatic hydrocarbon monomer can be obtained. Since the composition is more excellent in the viscosity of the composition, there is a tendency to ensure a sufficiently good product strength. In addition, when the molecular weight component of 1,000,000 or more is 20% or less, it is possible to ensure sufficiently good moldability. Further, the ratio of the above molecular weight component of 1,000,000 or more can be measured by the method described in the examples below.

In the present embodiment, the vinyl aromatic hydrocarbon polymer composition preferably has a tensile viscosity measured at 200 ° C and 2500 Pa·sec of 100,000 Pa·sec or more and 1,000,000 Pa·sec or less, more preferably 200,000 Pa. ‧ sec or more and 1 million Pa ‧ sec or less, and more preferably 220,000 Pa ‧ sec or more and 900,000 Pa ‧ sec or less, and more preferably 300,000 Pa ‧ sec or more and 800,000 Pa ‧ sec or less Tensile viscosity measured at 200 ° C, 2500 Pa ‧ sec When it is 100,000 Pa sec or more, the product strength tends to be sufficiently good, and when the tensile viscosity measured at 200 ° C and 2500 Pa sec is 1,000,000 Pa ‧ sec or less, sufficient molding processability can be ensured. The tendency. Further, the above-mentioned tensile viscosity can be measured by the method described in the examples below.

Furthermore, in the present embodiment, the degree of branching of the vinyl aromatic hydrocarbon polymer composition is 0.30 or more and less than 0.90, and is preferably 0.30 or more, and more preferably 0.40 or more from the viewpoint of moldability. It is preferably more than 0.50. On the other hand, from the viewpoint of elongational viscosity, it is preferably less than 0.90, more preferably 0.85 or less, still more preferably 0.80 or less. When the degree of branching is less than 0.90, there is a tendency that the number of branches in the molecule can be sufficiently ensured, and a composition having a sufficiently high tensile viscosity can be obtained, so that it is possible to obtain both the moldability and the mechanical properties after the container is formed. The tendency to make a foam. Further, when the degree of branching is 0.30 or more, it is possible to ensure sufficiently good moldability. The degree of branching can be expressed by the ratio of the inherent viscosity logarithm of the weight average molecular weight = 1,000,000 measured by the absolute molecular weight measurement multi-detection GPC/SEC system (for example, Viscotek TDAmax by Spectris Co., Ltd.).

In the present embodiment, the branched vinyl aromatic hydrocarbon polymer (B) is preferably a dispersed particle having a particle diameter of 50 nm or less among the spot particles dispersed in the linear vinyl aromatic hydrocarbon polymer (A). An electron microscope photograph magnified 100,000 times was present in 0 or more and 1000 or less dot-shaped particles per 4 μm ² area. The number of each of the 4 μm ² areas of the dot-like particles is more preferably 0 or more and 800 or less, more preferably 0 or more and 600 or less, and still more preferably 0 or more and 400 or less, and particularly preferably 0 or less. More than 200 or less, preferably 0 (no point particles). Further, in the case of the number of 4 μm ² of the dispersed particles having a particle diameter of 50 nm or less, the 80 nm ultrathin section cut out from the vinyl aromatic hydrocarbon polymer composition of the present embodiment can be dyed with tannic acid, and then Photographs of transmissive electron microscopy were obtained. Here, the dot-like particles mean particles having no occlude structure inside, that is, non-so-called core-shell particles or salami particles. Further, the occluded particles are polybutadiene rubber in which a plurality of small polystyrene particles are clogged inside, and the core particles are polybutadiene rubber containing one polystyrene particle inside. In addition, in the form in which the point particles are agglomerated, the number of point particles in the agglomerated form is calculated separately. When a plurality of core particles and occluded particles are present in the vinyl aromatic hydrocarbon polymer composition, the rigidity tends to decrease. However, as long as it does not harm the effect of the vinyl aromatic hydrocarbon polymer composition of the present embodiment, These core particles and occluded particles are contained. Further, the above particle diameter can be measured by the method described in the examples below.

In the vinyl aromatic hydrocarbon polymer composition used in the present embodiment, an additive conventionally used in the field of styrene resins, such as an antioxidant, a lubricant, and a core, may be used in combination insofar as the object of the present embodiment is not impaired. The agent, the flame retardant, the colorant, and the like may be used as the vinyl aromatic hydrocarbon polymer composition. The above-mentioned additives are not particularly limited, and examples thereof include a nucleating agent such as talc, a plasticizer such as flowing paraffin or white mineral oil, stearic acid, hexadecanic acid, zinc stearate, calcium stearate, and magnesium stearate. Such as lubricants, flame retardants such as hexabromocyclododecane, titanium oxide, carbon black, etc. Coloring agents, etc. Further, the styrene resin may be ingot, and as an external lubricant of the ingot, ethiylethyl stearylamine, zinc stearate, magnesium stearate or the like may be applied to the ingot.

The antioxidant is a component of a peroxide radical such as a hydrogen peroxide radical generated during thermoforming or light exposure, or a component for decomposing a peroxide such as hydrogen peroxide. In other words, the antioxidant is not particularly limited, and is, for example, a hindered phenol antioxidant or a peroxide decomposer. The former can be used as a free radical chain terminator, and the latter can further decompose the peroxide formed in the system into a stable alcohol to prevent auto-oxidation. Specific examples of the hindered phenol-based antioxidant in the above antioxidant are not limited to the following, and examples thereof include 2,6-di-tert-butyl-4-methylphenol, styrenated phenol, and n-octadecyl-3. -(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2- Tributyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl methacrylate, 2-[1-(2-hydroxy-3, 5-di-t-pentylphenyl)ethyl]-4,6-di-third-pentyl phenyl methacrylate, 4,4'-butylene bis(3-methyl-6-third Butyl phenol), 4,4'-thiobis(3-methyl-6-tert-butylphenol), alkylated bisphenol, hydrazine [methylene-3-(3,5-di- Tributyl-4-hydroxyphenyl)propionate]methane, 3,9-bis[2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)-propenyl) Oxy]-1,1-dimethylethyl]-2,4,8,10-nonnero[5.5]undecane and the like. Further, specific examples of the peroxide decomposing agent in the above antioxidant are not limited to the following, however, there are decylphenylphosphine, triphenylphosphine, and ginseng (2,4-di-t-butylphenyl) An organophosphorus peroxide decomposing agent such as phosphine or dilauryl-3,3'-thiodipropionate or dimyristyl-3,3'-thiodi Propionate, distearyl-3,3'-thiodipropionate, neopentyl pentoxide (3-lauryl thiopropionate), Twenty-three-3,3'-thio An organic sulfur-based peroxide decomposing agent such as dipropionate or 2-mercaptobenzimidazole. The amount of the antioxidant added is preferably 0.01 parts by mass or more and 1 part by mass or less, more preferably 0.1 part by mass or more and 0.5 part by mass or less based on 100 parts by mass of the vinyl aromatic hydrocarbon polymer composition.

The type of the above-mentioned flame retardant is preferably, for example, hexabromocyclododecane, brominated SBS block polymer, or 2,2-dual from the viewpoints of flame retardancy and compatibility with a styrene resin. A bromine-based flame retardant such as 4' (2", 3"-dibromoalkoxy)-3',5'-dibromophenyl)-propane, and the following brominated bisphenol-based flame retardant. However, this is not limited to the above.

The brominated bisphenol-based flame retardant is not limited to the following, and examples thereof include tetrabromobisphenol A, tetrabromobisphenol A-bis(2,3-dibromopropyl ether), and tetrabromobis. Phenol A-bis(2,3-dibromo-2-methylpropyl ether), tetrabromobisphenol S, tetrabromobisphenol S-bis(2,3-dibromopropyl ether), tetrabromobisphenol S -bis(2,3-dibromo-2-methylpropyl ether), tetrabromobisphenol F, tetrabromobisphenol F-bis(2,3-dibromopropyl ether), tetrabromobisphenol F-double (2,3-dibromo-2-methylpropyl ether) tetrabromobisphenol A-bis(allyl ether), tetrabromobisphenol A polycarbonate oligomer, tetrabromobisphenol A oligomer ring An oxy-additive or the like. Among the above brominated bisphenol-based flame retardants, in particular, tetrabromobisphenol A bis(2,3-dibromopropyl ether), tetrabromobisphenol A-bis(2,3-dibromopropyl ether) It is preferred because it is less likely to be decomposed when it is kneaded with a polystyrene resin, and has a high flame retarding effect and is easy to exhibit. Further, when tetrabromobisphenol A-bis(2,3-dibromopropyl ether) and tetrabromobisphenol A-bis(2,3-dibromo-2-methylpropyl ether) are used together, flame retardancy is obtained. With a tendency to be excellent in thermal stability, Therefore, it is better.

Further, as the bromine-based flame retardant, a brominated isocyanurate-based flame retardant such as the following is preferably used in combination as a flame retardant auxiliary. The above-mentioned brominated isocyanurate-based flame retardant is not limited to the following, and examples thereof include, for example, iso-p-cyanuric acid mono(2,3-dibromopropyl) ester and isomeric cyanuric acid. (2,3-dibromopropyl) ester, tris(2,3-dibromopropyl)isophthalocyanate, mono (2,3,4-tribromobutyl) isomeric cyanurate, Isophthalic acid bis(2,3,4-tribromobutyl) ester, isomeric isocyanate ginseng (2,3,4-tribromobutyl) and the like. Further, among the above brominated isocyanurates, it is preferred because tris(2,3-dibromopropyl) isocyanurate exhibits an extremely high flame retarding effect.

The content of the bromine-based flame retardant in the extruded foam is preferably 0.1 parts by mass or more and 10 parts by mass or less, more preferably 1 part by mass or more and 9 parts by mass based on 100 parts by mass of the vinyl aromatic hydrocarbon polymer composition. More preferably, it is 2 parts by mass or more and 8 parts by mass or less. When it is 0.1 part by mass or more, the flame retardancy which is desired in the present embodiment is sufficiently ensured, and when it is 10 parts by mass or less, it is possible to obtain a sufficiently good moldability when the extruded foam is produced.

(block copolymer)

The block copolymer of the present embodiment is composed of a vinyl aromatic hydrocarbon and a conjugated diene, and may also be referred to as an aromatic vinyl-conjugated diene block copolymer. The block copolymer can be produced by a method in which at least one conjugated diene monomer and at least one aromatic vinyl monomer are solution-polymerized by, for example, a living anionic polymer.

The conjugated diene monomer is not particularly limited, but However, for example, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 3-methyl-1,3- One type or two or more types may be used for pentadiene, 1,3-pentadiene, 1,3-hexadiene or the like. Preferred monomers are 1,3-butadiene and isoprene.

Further, the above aromatic vinyl monomer is not particularly limited, and examples thereof include styrene, p-methylstyrene, α-methylstyrene, 3,5-dimethylstyrene, and vinylethyl. Benzene, vinyl xylene, vinyl naphthalene, etc. may be used alone or in combination of two or more. Particularly preferred is styrene. Examples of the hydrocarbon solvent used for the solution polymerization include aliphatic hydrocarbons such as butane, pentane and hexane, alicyclic hydrocarbons such as cyclopentane and cyclohexane, and aromatic hydrocarbons such as benzene, toluene and xylene. Preferable examples thereof include hexane and cyclohexane.

A more detailed production method of the block copolymer of the present embodiment is as follows. That is, a method of preparing a living anionic polymer, followed by adding a conjugated diene monomer, adding an aromatic vinyl monomer after the polymerization of the monomer, and continuing the polymerization reaction; Then, it is produced by a method of adding a conjugated diene monomer and an aromatic vinyl monomer, and continuing the polymerization reaction. Further, in the hydrocarbon solvent in which the conjugated diene monomer is present, a living anionic polymer is added, and after the polymerization of the monomer is completed, an aromatic vinyl monomer is added and the polymerization reaction is continued; and a conjugated diene is present. The active anionic polymer is added to the hydrocarbon solvent of the body and the aromatic vinyl monomer, and the polymerization reaction is continued.

The block copolymer used in the present embodiment is not limited to the following, however, for example, the linear chain represented by the following general formulae (1) to (8) may be used. A block copolymer or a radial block copolymer, or any mixture of such polymer constructions.

(1)c-(A-B)n

(2) c-(B-A)n

(3) c-(B-A-B)n

(4) c-(A-B-A)n

(5) c-(A-B)n-A

(6) c-(B-A)n-B

(7)c-(B-A-A-B)n

(8)c-(A-B-B-A)n

(In any one of the general formulae (1) to (8), B represents a conjugated diene polymer or a random copolymer of a conjugated diene and an aromatic vinyl compound, and may have A tapered block in which the ratio of the aromatic vinyl compound is gradually increased. A represents a polymer block having an aromatic vinyl compound as a main component, and c represents a residue of a living anionic polymer or a residue of a coupling agent. An integer of 1 to 10, and the structure of the polymer chain bonded to c may be the same or different. In addition, the above "as a host" means more than 50%.)

In the present embodiment, the amount of the component component derived from the conjugated diene of the block copolymer is 5% by mass or more and 40% by mass or less, and the amount of the component component derived from the vinyl aromatic hydrocarbon in the block copolymer is preferably 60% by mass or more and 95% by mass or less. The amount of the constituent component derived from the conjugated diene of the block copolymer is more preferably 7% by mass or more and 38% by mass or less, still more preferably 10% by mass or more and 35% by mass or less. Further, the amount of the constituent component derived from the vinyl aromatic hydrocarbon of the above block copolymer is more preferably 62. The mass% or more is 93% by mass or less, and more preferably 65% by mass or more and 90% by mass or less. When the amount of the constituent component derived from the conjugated diene of the block copolymer is 5% by mass or more, the hydrogen of the conjugated diene portion may be detached or the vinyl aromatic hydrocarbon chain may be bonded to the vinyl group. In the tendency of being sufficient, there is a tendency to easily obtain a target high molecular weight component. In addition, when the amount of the constituent component derived from the conjugated diene is 40% by mass or less, the block copolymer tends to be prevented from aggregating, and even if the branched vinyl aromatic hydrocarbon polymer (B) is present in the straight In the chain vinyl aromatic hydrocarbon polymer (A), the state of existence is uniform and it is not a particle, or even if it is a particle, it tends to maintain a dot-like form. Further, the amount of the vinyl bond in the block copolymer is preferably 7% or more and 70% or less. Further, the amount of the vinyl bond is more preferably 10% or more and 65% or less, and still more preferably 13% or more and 60% or less. When the amount of the vinyl bond is 7% or more, the target high molecular weight component tends to be sufficiently ensured. In addition, when the amount of the vinyl bond is 70% or less, the amount of formation of the high molecular weight component tends to be controlled within a suitable range, and the moldability tends to be sufficiently ensured. Further, the amount of the component derived from the conjugated diene, the amount of the component derived from the vinyl aromatic hydrocarbon, and the amount of the vinyl bond can be measured by the method described in the examples below. In other words, the amount of the component derived from the conjugated diene, the amount of the component derived from the vinyl aromatic hydrocarbon, and the amount of the vinyl bond are obtained in the branched vinyl aromatic hydrocarbon polymer (B) of the present embodiment. Previously, it was measured using a block copolymer as a raw material.

(Method for producing vinyl aromatic hydrocarbon polymer composition)

a vinyl aromatic hydrocarbon polymer composition used in the embodiment, For example, it can be obtained by polymerizing a vinyl aromatic hydrocarbon monomer in the presence of the above block copolymer. That is, the branched vinyl aromatic hydrocarbon polymer can be obtained by the detachment of the hydrogen of the conjugated diene portion of the above block copolymer or the bonding of the vinyl aromatic hydrocarbon chain to the vinyl group. With the linear vinyl aromatic hydrocarbon polymer (A), the branched vinyl aromatic hydrocarbon polymer (B) is made into a high molecular weight component.

The above vinyl aromatic hydrocarbon monomer may be styrene, α-methylstyrene, o-, m-, and p-methylstyrene, ethylstyrene, propylstyrene, butylstyrene, chlorine Styrene, dichlorostyrene, bromostyrene, dibromostyrene, and the like. Among them, styrene is preferred. The vinyl aromatic hydrocarbon monomer may be used alone or in combination of two or more.

The method for producing the vinyl aromatic hydrocarbon polymer composition used in the present embodiment is not limited to the following. However, for example, a vinyl aromatic hydrocarbon is dissolved in a vinyl aromatic hydrocarbon monomer. The solution of the block copolymer formed of the conjugated diene is produced by using general bulk polymerization, solution polymerization, suspension polymerization, or the like. Further, in the present embodiment, in order to adjust the molecular weight of the linear vinyl aromatic hydrocarbon polymer (A) and the molecular weight of the branched vinyl aromatic hydrocarbon polymer (B), a polymerization initiator, a solvent, or the like may be used. Chain transfer agent.

The above polymerization initiator is not limited to the following, however, for example, an organic peroxide can be used. The organic peroxide is not particularly limited, and examples thereof include 1,1-bis(t-butylperoxy)cyclohexane and 1,1-bis(t-butylperoxy)3,3. , peroxy ketals such as 5-trimethylcyclohexane, di-butyl peroxide, 2,5-dimethyl-2,5-di (t-butyl peroxyl) Dialkyl peroxides such as hexane, perylene oxides such as benzamidine peroxide and m-tolylmethyl peroxide, and peroxy esters such as dimyristyl peroxydicarbonate , ketone peroxides such as cyclohexanone peroxide, hydrogen peroxide such as p-methahydroperoxide, 2,2-bis(4,4-di-t-butylperoxycyclohexyl) ) propane, 2,2-bis(4,4-di-p-pentylperoxycyclohexyl)propane, 2,2-bis(4,4-di-t-butylperoxycyclohexyl)butane, 2 A polyfunctional starter such as 2-bis(4,4-di- cumenylcyclohexyl)propane. Among the above, 2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane is preferred from the viewpoint of increasing the stretching viscosity.

The above organic peroxide can be added to the polymerization system (polymerization raw material solution or solution in the middle of polymerization) in any step of polymerization of the styrene monomer. These organic peroxides may be added to the polymerization raw material solution, or may be added to the solution in the middle of the polymerization as needed. The amount of the organic peroxide to be added is preferably 0.0005 parts by mass or more and 0.2 parts by mass or less, more preferably 0.01 parts by mass or more and 0.1 parts by mass or less, more preferably 0.03 parts by mass or more and 0.08 parts or more based on 100 parts by mass of the polymerization raw material solution. Below the mass. When the amount of the organic peroxide added is 0.2 parts by mass or less, a large amount of heat of reaction generated during the polymerization tends to be favorably controlled, and it is preferable from the viewpoint of control of the polymerization reaction.

The solvent is not limited to the following, however, for example, toluene, ethylbenzene, xylene or the like can be used. The amount of the solvent to be used is not particularly limited. However, it is preferably in a range of from 0% by mass to 50% by mass based on 100% by mass of the polymerization raw material solution. For the above chain transfer agent, for example, n-dodecyl mercaptan, t-dodecyl mercaptan, α-methyl group can be used. Styrene dimer and the like. The amount of the chain transfer agent to be used is preferably 0.01% by mass or more and 2% by mass or less, more preferably 0.1% by mass or more and 1% by mass or less, more preferably 0.2% by mass or more and 0.8% by mass based on 100% by mass of the polymerization raw material solution. %the following. In the method for producing a vinyl aromatic hydrocarbon polymer composition of the present embodiment, the reaction temperature is preferably 80 ° C or more and 200 ° C or less, more preferably 90 ° C or more and 180 ° C or less. When the reaction temperature is 80° C. or more, sufficient productivity can be ensured, and it can be said to be an industrially suitable condition. On the other hand, when the reaction temperature is 200 ° C or lower, it is preferred because the amount of formation of the low molecular weight polymer is easily controlled to an appropriate range. When the target molecular weight is adjusted, it is not limited to the above reaction temperature (polymerization temperature), and may also be controlled by a starting dose, a solvent amount, a chain transfer dose, and the like. Further, in the method for producing a vinyl aromatic hydrocarbon polymer composition of the present embodiment, the reaction time is usually 0.5 hours or more and 20 hours or less, preferably 2 hours or more and 10 hours or less. When the reaction time is 0.5 time or longer, the reaction tends to proceed sufficiently, and when it is 20 hours or less, it is preferable from the viewpoint of productivity.

The polymerization conversion ratio of the vinyl aromatic hydrocarbon monomer is not particularly limited, but is preferably 40% or more in terms of industrial knowledge. The polymerization solution thus obtained can be separated from the target vinyl aromatic hydrocarbon polymer composition by removing the unreacted monomer and the solvent, and when it is suspension polymerization, it can be directly supplied to the next step.

<Method of Manufacturing Extruded Foam Sheet>

In the present embodiment, the extruded foam is produced as a method of extruding the foamed sheet. For example, the vinyl aroma of the present embodiment can be used first in an extruder connected to a circular die. The hydrocarbon polymer composition is melted and kneaded, and the melt kneaded material is extruded from the annular opening of the circular die in a foamed state to form a cylindrical foam. Next, the foamed body and the outer peripheral surface of the cooling mandrel which is larger than the diameter of the opening provided in front of the circular die are extended in the circumferential direction, and the cooled object is continuously cut along the extrusion direction. The conventional method of breaking and unfolding. However, this is not limited to the above. Further, as the foaming agent and the foaming nucleating agent at the time of extrusion foaming, a commonly used one can be used. The foaming agent is not particularly limited. For example, butane, pentane, chlorofluorocarbon, water, or the like can be used, and it is preferably a butane. Further, the foaming nucleating agent is not particularly limited, and for example, talc or the like can be used. The polystyrene-based resin extruded foam sheet preferably has a thickness of 0.5 mm to 5.0 mm, an apparent density of 50 g/L to 300 g/L, and a basis weight of 80 g/m ² to 300 g/m ² . Moreover, the foamed sheet can be laminated on the extruded sheet. For the type of film to be used, a general polystyrene can be used.

<container>

The extruded foam sheet of the present embodiment described above can be vacuum-formed by a conventionally known method such as vacuum forming, pressure forming, vacuum forming, double-sided vacuum forming, or press forming to form a disk, a tantalum container, and a natto container. Wait for the container. That is, the container of the present embodiment is obtained by vacuum-molding the extruded foam of the present embodiment. The type of vacuum molding and the type of the container are not limited to the above. In the container of the present embodiment, for example, the extruded foam sheet obtained as described above can be processed into a food sheet having a length of 12 cm, a width of 20 cm, and a depth of 2 cm by using a vacuum forming machine as a direction of extrusion in the transverse direction. container. The above vacuum forming conditions are not limited to the following, however, It is generally preferred to select a condition of 120 to 150 °C.

<Method for Producing Plate-Type Extrusion Foam>

When the extruded foam of the present embodiment is produced as a plate-like extruded foam, it can be produced from the above-mentioned vinyl aromatic hydrocarbon polymer composition. More specifically, the plate-like extruded foam of the present embodiment can be produced by foaming the above vinyl aromatic hydrocarbon polymer composition. At the time of the above foaming, it can be carried out by a conventionally known method. Further, as the foaming agent and the foaming nucleating agent at the time of extrusion foaming, a commonly used one can be used. The foaming agent is not particularly limited. For example, butane, pentane, chlorofluorocarbon, water, or the like can be used, and it is preferably a butane. The foaming nucleating agent is not particularly limited, and, for example, talc or the like can be used. The plate-like extruded foam of the present embodiment preferably has a thickness of 5 mm or more and 100 mm or less, a foam density of 20 g/L or more and 50 g/L or less, and a foaming cell diameter of 0.005 mm from the viewpoint of heat resistance and the like. The above 0.5 mm or less is preferably produced by the above-mentioned value. Here, the foaming cell diameter of the plate-like extruded foam can be the same as the particle diameter measurement described later, and the penetrating electron micrograph is read by a scanner by an ultrathin section method, and the particle analysis software is used. Image analysis software manufactured by Asahi Kasei Engineering Co., Ltd., product name "A like Jun").

[Examples]

The specific embodiments of the present invention are shown in the following examples and comparative examples. However, the present invention is not intended to limit the embodiments of the present invention.

In each case, various evaluations of vinyl aromatic hydrocarbon polymer compositions, extruded foam sheets and containers, and plate-like extruded foams The price is based on the following method.

[Measurement, evaluation method]

(1) Content of vinyl aromatic hydrocarbons and conjugated diene in block copolymers of vinyl aromatic hydrocarbons and conjugated dienes

1H-NMR was measured and calculated using the peak area of the aromatic ring derived from the vinyl aromatic hydrocarbon and the peak area of the vinyl bond from the conjugated diene. Further, the measuring device was JEOL-ECA500 manufactured by JEOL Ltd.

(2) content of conjugated diene in the composition of the vinyl aromatic hydrocarbon polymer

The content of the conjugated diene in the vinyl aromatic hydrocarbon polymer composition is determined by using a composition in which the content of the conjugated diene prepared in advance is 0, 2.0% by mass, or 4.0% by mass, respectively. A regression line prepared from the conjugated diene content calculated by the method of the above (1).

(3) The amount of vinyl bond

0.1 g of the sample for measurement was completely dissolved in 10 mL of carbon disulfide, and the spectrum was measured using an infrared spectrophotometer ["FTIR-8400S" manufactured by Shimadzu Corporation) using a 0.5 mm tank. Secondly, from the obtained spectrum by the Hampton method [R., R.: AnaLyt. Chem., 21 (1949), p. 923] to determine the amount of vinyl bonding,

(4) Melt flow rate (MFR)

The ingots of the respective examples were subjected to a melt flow rate measurement at a temperature of 200 ° C according to ISO 1133. The melt flow rate is used as an indicator of fluidity.

(5) stretch viscosity

Using a double capillary rheometer, the shear viscosity and elongation viscosity data were obtained at a shear rate of 40 to 1000 sec-1, and a graph of shear viscosity and elongational viscosity was prepared. The vinyl aromatic hydrocarbon was calculated at a shear viscosity of 2500 Pa·sec. The tensile viscosity of the polymer composition. The detailed conditions at this time are as follows.

Use device: Double capillary flow rheometer (type RH7-2) made by ROSAND PRECISION

Long size: 1mmφ×16mmL

Short size: 1mmφ×0.25mmL

Temperature: 200 ° C

Preheating time: After the piston is lowered, it is preheated for 6 minutes with a long side pressure of 5 MPa. Thereafter, it was preheated for 3 minutes with a long side pressure of 3 MPa.

(6) Decomposition of osmium tetroxide

A mixed decomposing agent of a ruthenium tetroxide solution and a third butyl hydroperoxide is used to oxidatively decompose the polymer in a chloroform solution to 90 ° C (IMKOLTHOFF, et al., J. Polym. Sci. 1, 429 ( In the method of 1946), the oxidatively decomposed polymer is recovered by methanol precipitation, and the ratio of the Z average molecular weight before and after the oxidative decomposition is calculated. In more detail, about 0.07 g of a sample of a vinyl aromatic hydrocarbon polymer composition is dissolved in 10 mL of chloroform, and a mixed decomposing agent of a third butyl alcohol solution and a third butyl alcohol solution of a third butyl hydroperoxide is added. 20 mL of 6 mL of 0.05% chloroform solution with osmium tetroxide was decomposed under reflux for 12 minutes in a 90 ° C bath. After cooling this, 200 mL of methanol was added to the solution to precipitate a polystyrene component while stirring. The mixture was separated by a glass filter, and the separated polystyrene component was dissolved in tetrahydrofuran (THF) for gel permeation chromatography (GPC) measurement. Samples. This sample for GPC measurement is based on the molecular weight measurement method (7) described later, and the Z average molecular weight before and after oxidative decomposition is measured as follows.

Ratio of Z average molecular weight before and after oxidative decomposition = (Z average molecular weight after oxidative decomposition) / (Z average molecular weight before oxidative decomposition)

(7) Molecular weight determination

The average molecular weight (Mn: number average molecular weight, Mw: weight average molecular weight, Mz: Z average molecular weight) of each was measured under the following conditions. Specifically, 20 mL of a methyl ethyl ketone/methanol mixed solvent (mixing mass ratio of 90/10) was added to about 1 g of the vinyl aromatic hydrocarbon polymer composition, and the mixture was dissolved by a vibration machine for 60 minutes. Next, the mixture was centrifuged at 20,000 rpm for 60 minutes at 0 ° C using a himac CR20 centrifugal separator equipped with a rotor of the R20A2 type, and the supernatant was subjected to a decantation method to obtain a soluble fraction. Thereafter, methanol was added to recover the residue. Next, it was dried under vacuum at room temperature to remove the solvent. Next, the recovered sample was measured under the following conditions. Further, the ratio of the molecular weight component of 1,000,000 or more is obtained by the following method: the peak of the relative molecular weight in terms of the horizontal axis polystyrene and the peak of the ultraviolet ray luminosity of the vertical axis obtained by the above measurement, which are calculated by integration A value obtained by a content ratio of a component having a relative molecular weight of 1,000,000 or more.

Use device: HLC8020 manufactured by Tosoh

Separate column: TSK-gel-GMHXL made by Tosoh

Determination of solvent: tetrahydrofuran

Sample concentration: 5 mg of the vinyl aromatic hydrocarbon polymer composition was dissolved in 10 mL of the solvent

Measuring temperature: 40 ° C

Flow rate: 0.35 mL/min

(8) Branching degree

First, the intrinsic viscosity of the weight average molecular weight = 1,000,000 was measured under the following conditions.

Equipment: Spectris (Company) Absolute molecular weight determination Multi-detection detector GPC/SEC system Viscotek TDA305

Light scattering detector wavelength: 670nm

Column: Tosoh, TSKgel G6000, 5000, 4000HXL

Determination of solvent: tetrahydrofuran

Measuring temperature: 40 ° C

Flow rate: The intrinsic viscosity was measured at 1.0 mL/min.

Based on the intrinsic viscosity obtained above, the following formula is calculated for the degree of branching when the weight average molecular weight is 1,000,000.

Branching degree = log (inherent viscosity of the composition) / log (intrinsic viscosity of standard PS) (standard PS: TOSOH, TSKstandard, POLYSTYRENE, F-80 (TS-201), molecular weight = 7.06 × 10 ⁵ )

(9) Determination of the number of particles below 50 nm

The transmission electron micrograph of the ultrathin sectioning method was used to measure the particle diameter of the selected dispersed particles in the dispersed particles observed in the region of 4 μm ² in the photograph to obtain the particle diameter. Further, the measuring apparatus was a transmission electron microscope HT7700 manufactured by Hitachi High Systems Co., Ltd. Further, the number of particles of the dispersed particles was measured in the following manner. In other words, the composition of each of the examples was cut out with an ultrathin section of 80 nm and stained with tannic acid, and then photographed by a transmission electron microscope to obtain a photograph having a magnification of 100,000 times. From this photograph, the number of particles having an area of 4 μm ^{2 was} determined as the dispersed particles having a particle diameter of 50 nm or less. Here, the particle diameter is a particle diameter in the case where the particle area in the photograph is set to correspond to the diameter of a circle. In addition, if the spot particles are in agglomerated form, the number of point particles in the agglutination form is calculated separately. In the measurement, the photograph was taken with a 1000 dpi resolution scanner, and the particle analysis software (image analysis software manufactured by Asahi Kasei Engineering Co., Ltd., product name "A") was used.

(10) Test of the strength of the web of the container

Fig. 1 is a view for explaining a method of measuring the strength of a web of an extruded foamed disk. The extruded foamed sheet was vacuum-formed into a disk as shown in Fig. 1, and the web strength of the resulting extruded foamed disk was measured. That is, the squeeze foaming disc fixed to the lower pressure plate for the compression test was subjected to a load of a pressurizing speed of 5 mm/min by projecting a compression load jig provided at a movable portion of the compression tester. Further, the size of the disk container used was 12 cm in length, 20 cm in width, and 2 cm in depth. The center portion of the long side of the upper end portion of the peripheral wall portion is pressed to be pressed at a speed of 5 mm/min at a speed of 5 mm/min so as to approach the long side of the long side to only 10 mm. The measurement was made as the web strength (refer to Fig. 1). In addition, the measuring apparatus was a table type precision universal testing machine (ALTOGRAPHIC AGS-5kNX) manufactured by Shimadzu Corporation.

(11) Deep extension formability

First, the extruded foam of each example was allowed to stand at 23 ± 3 ° C and a relative humidity of 50 ± 5% for 20 days. Thereafter, using the inventoris-made sheet container forming machine, the foam is sandwiched by the fixing frame of the sheet forming machine, and the average temperature of the heater is At 240 ° C, the ambient temperature was heated at 160 ° C for 90 seconds. Next, each of the cup molds (temperature: 60 ° C) having a depth of 10 cm and a depth of 3 cm and a depth of 6 cm was slid into a fixing frame and vacuum-molded, and 100 molded bodies were separately formed. It was visually confirmed whether or not cracks were formed on the side surface of the molded body, and the number of formed bodies capable of forming no cracks was used as an index of deep drawability.

(12) Foam density

The foam density of each example was measured in accordance with ISO 10350. Further, the measuring device was a hydrometer (SGM-220-60 measuring instrument) manufactured by Shimadzu Corporation.

(13) Foaming ratio

The expansion ratio is calculated by the following formula using the value (ρf) of the foam density obtained by the above (12) and the density (ρ) of the vinyl aromatic hydrocarbon polymer composition.

Foaming ratio = ρ / ρf

(14) basis weight

The extruded foam was cut out to 100 cm ² , and the mass was measured, and the mass per 1 m ^{2 was} converted.

(15) Surface roughness inspection

The surface of the extruded foam was visually inspected to confirm the presence or absence of surface roughness such as unevenness.

(16) Independent bubble rate of plate-like extruded foam

First, from the plate-like extruded foam obtained in each of the examples, five test pieces having a flat square shape of 25 mm on one side were cut out. In addition, when the test piece was cut out from the plate-like extruded foam, the surface of the foamed body was not included in the test piece, and the inside of the plate-shaped extruded foam was cut out. Next, the obtained test pieces of five sheets were superposed on each other in the thickness direction to form a laminate. The apparent volume V1 of the laminate was measured by NOGIS. Next, the volume V2 of the above laminated body was measured by the 1-2-1 air pressure method in accordance with ASTM D2856-87, and the closed cell ratio was calculated according to the following formula. In addition, the volume V2 of the laminated body was measured using the air comparative type hydrometer model 1000 sold by Tokyo Science and Technology Co., Ltd.

Independent bubble rate (%) = 100-100 × (V1-V2) / V1

(17) Compressive strength

The compressive strength was measured in accordance with the JIS K7220 method.

[Manufacture of Block Copolymer B-1]

A vinyl aromatic hydrocarbon ‧ conjugated diene copolymer (block copolymer B-1) having a vinyl aromatic hydrocarbon content of 90% by mass and a conjugated diene content of 10% by mass was produced in the following manner. In other words, a stirring apparatus having a volume of 10 L which was previously washed and dried, and an autoclave having a jacket were placed in a nitrogen gas atmosphere, and n-butyl group was added to a cyclohexane solution containing 30 parts by mass of styrene at a concentration of 25% by mass. 0.095 parts by mass of lithium was polymerized at 50 °C. Next, a cyclohexane solution containing 30 parts by mass of styrene and 10 parts by mass of 1,3-butadiene in a concentration of 25% by mass was added and reacted for 60 minutes. Further, a cyclohexane solution containing 30 parts by mass of styrene at a concentration of 25% by mass was added and reacted for 30 minutes. Thereafter, in order to completely stop the polymerization, a molar amount of ethanol such as n-butyllithium or the like is added to the reactor, and as a stabilizer, 0.3 parts by mass of methacrylic acid 2-[(meth) is added to 100 parts by mass of the polymer. 1-(2-Hydroxy-3,5-di-p-pentylphenyl)ethyl]-4,6-di-tripentylphenyl ester. Secondly, the target linear linear aromatic hydrocarbon ‧ conjugated diene is recovered by removing the solvent Copolymer (block copolymer B-1). The block copolymer B-1 thus obtained was a block copolymer of an S1-(S/B)-S2 structure having a styrene content of 90% by mass. In addition, in the formula of the block structure described above, the addition of S, B, and S/B numbers respectively indicates that the vinyl aromatic hydrocarbon block (S) and the conjugated diene polymer are embedded in the block copolymer. Segment (B), a block copolymer (S/B) containing a random copolymer, which are labeled the same below.

[Manufacture of Block Copolymer B-2]

A vinyl aromatic hydrocarbon ‧ conjugated diene copolymer (block copolymer B-2) having a vinyl aromatic hydrocarbon content of 80% by mass and a conjugated diene content of 20% by mass was produced in the following manner. In other words, the stirring device having a volume of 10 L which was previously washed and dried, and the jacketed autoclave were placed in a cyclohexane solution containing 10 parts by mass of 1,3-butadiene at a concentration of 25% by mass in a nitrogen atmosphere. After adding 0.095 parts by mass of n-butyllithium to 0.3 mol of tetramethylamethylenediamine relative to n-butyllithium, polymerization was carried out at 50 °C. Next, a cyclohexane solution containing 80 parts by mass of styrene at a concentration of 25% by mass was added and reacted for 60 minutes. Thereafter, a cyclohexane solution containing 10 parts by mass of 1,3-butadiene at a concentration of 25% by mass was added and reacted for 15 minutes. Thereafter, in order to completely stop the polymerization, a molar amount of ethanol such as n-butyllithium or the like is added to the reactor, and as a stabilizer, 0.3 parts by mass of methacrylic acid 2-[(meth) is added to 100 parts by mass of the polymer. 1-(2-Hydroxy-3,5-di-p-pentylphenyl)ethyl]-4,6-di-tripentylphenyl ester. Next, the target linear linear aromatic hydrocarbon ‧ conjugated diene copolymer (block copolymer B-2) was recovered by removing the solvent. The block copolymer B-2 thus obtained was a linear block copolymer of a B-S-B structure having a styrene content of 80% by mass.

[Manufacture of block copolymers B-3 to B-8]

Similarly to the block copolymer B-2, a vinyl aromatic hydrocarbon ‧ conjugated diene copolymer (block copolymer B) having a vinyl aromatic hydrocarbon content as specified in Table 1 and a conjugated diene content -3 to B-8), the amount of n-butyllithium and tetramethylethylenediamine added was adjusted so as to have the amount of vinyl bond specified in Table 1, and the linear structure of the BSB structure was obtained. Block copolymers B-3 to B-8.

[Example 1]

[Manufacture of vinyl aromatic hydrocarbon polymer composition a]

2,2-bis (4,4-) was added to 100 parts by mass of a mixed liquid of 84.5 mass% of styrene, 8 mass% of ethylbenzene, and 7.5% by mass of block copolymer B-1 described in Table 1. 0.015 parts by mass of the obtained polymerization raw material liquid of ditributylperoxycyclohexyl)propane was continuously charged at 0.78 L/Hr in a 4.6 L fully mixed reactor, and adjusted to 103 °C. The solid content concentration at the outlet of the reactor was 40% by mass. Further, the above solid content concentration was calculated by the following method. That is, first, a polymerization liquid of w1 (g) was charged in an aluminum cup, and volatile components such as unreacted monomers in the polymerization liquid were volatilized at 230 ° C for 15 minutes under reduced pressure. Thereafter, the residual solid component (reaction product) w2 (g) was calculated using the following formula.

(solid content concentration) = w2 / w1 × 100 (%)

The polymer solution of the fully mixed reactor is then continuously charged into a 3-zone temperature-controlled 1.5 L laminar flow reactor-1 and a 3-zone temperature-controlled 1.5 L laminar flow reactor arranged in series therewith. -2 in. Adjust the temperature of the laminar flow reactor-1 to 129 ° C / 134 ° C / 139 °C, and the temperature of the laminar flow reactor-2 was adjusted to 150 ° C / 155 ° C / 165 ° C.

The self-polymerization reactor is continuously supplied in sequence in a devolatilizer of a three-stage exhaust uniaxial extruder which removes volatile components such as unreacted monomers and a polymerization solvent and is connected to an exhaust pressure of 240 ° C and 1.333 kPa. The polymer solution was discharged to prepare a resin. The final solids concentration was 80.5%. The polymerization conditions are shown in Table 2. Further, the GPC of the obtained styrene resin composition was subjected to molecular weight measurement (before and after decomposition of citric acid), measurement of branching degree, measurement of melt flow rate, measurement of particle diameter, and elongation of adhesion. This result is shown in Table 5.

The butadiene-converted rubber amount of the obtained composition was 0.6% by mass, the ratio of the Z average molecular weight before and after the oxidative decomposition was 0.6, the branching degree was 0.81, the molecular weight component amount of 1,000,000 or more was 8.1% by mass, and the melt flow rate was 1.1 g. /10 minutes. The tensile viscosity measured at 200 ° C, 2500 Pa sec was 482,000 Pa ‧ sec. There are no point particles.

[Manufacture of extruded foam sheets]

Using an extrusion foaming machine having a circular die having a diameter of 150 mm, 0.15 parts by mass of talc (average particle diameter: 1.3 μm) as a foaming nucleating agent was added to 100 parts by mass of the vinyl aromatic hydrocarbon polymer composition. The styrene-based resin composition obtained by dissolving 4 parts by mass of liquefied butane as a foaming agent was extruded and foam-molded to produce an extruded foam sheet having a sheet thickness of 1.9 mm. The temperature of the resin-melted region was adjusted to 200 to 230 ° C, the temperature of the rotary cooler was 130 to 170 ° C, and the mold temperature was 150 ° C. The foam which was just extruded and foamed was cooled on a cooling mandrel, and cut at a point on the circumference with a cutter to obtain a width of 1000 mm and a foam density of 68 g/L (expansion ratio: 15.5 times). , basis weight: 149 g/m ² of extruded foamed sheet. The physical properties and the like of the above extruded foamed sheet are shown in Table 5.

[Manufacture of containers]

The extruded foam sheet obtained above was used as a molding material, and the above-mentioned container molding machine was used, and the average temperature of the heater was set to 210 ° C, the ambient temperature was 130 ° C, and the preheating time was 60 seconds to perform vacuum forming. A disk container for testing the web strength of 12 cm in length, 20 cm in width, and 2 cm in depth. The measurement results of the web strength of the above-described web strength test disc container are shown in Table 5.

[Examples 2 to 10]

The composition of the vinyl aromatic hydrocarbon polymer of Examples 2 to 10 was produced in the same manner as in Example 1 except that the type, the amount of each addition, and the polymerization conditions of the block copolymer were changed as described in Table 2. Extruded foam sheets of materials b to h and q and r, and disk containers for web strength test. The methyl methacrylate used in Table 2 was manufactured by Asahi Kasei Chemicals Co., Ltd., and butyl acrylate was produced by East Asia Synthesis, α-methylstyrene dimerization system and Wako Pure Chemical Industries. The physical properties and the like are shown in Table 5.

[Comparative Example 1]

[Manufacture of styrene resin t]

2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane was added to 100 parts by mass of a mixed solution of 82% by mass of styrene and 18% by mass of ethylbenzene (in Table 2, Approximately 0.015 parts by mass of the obtained polymerization raw material liquid, which is abbreviated as "PTA"), was continuously loaded into a 4.6L fully mixed reactor at 0.78 L/Hr, and adjusted. The whole is 107 °C. The solid content concentration at the outlet of the reactor was 31% by mass. The polymer solution of the fully mixed reactor is then continuously charged into a 3-zone temperature-controlled 1.5 L laminar flow reactor-1 and a 3-zone temperature-controlled 1.5 L laminar flow reactor arranged in series therewith. -2. The temperature of the laminar flow reactor-1 was adjusted to 115 ° C / 124 ° C / 129 ° C, and the temperature of the laminar flow reactor - 2 was adjusted to 145 ° C / 150 ° C / 160 ° C. Except for the above, the vinyl aromatic hydrocarbon polymer composition of Comparative Example 1 was produced in the same manner as in Example 1, and the foamed sheet and the disk strength test disk container were extruded. The physical properties and the like are shown in Table 5.

[Comparative Examples 2 to 7, 10 to 11]

The ethylene of Comparative Examples 2 to 7, 10 to 11 was produced in the same manner as in Comparative Example 1, except that the type of the block copolymer, the amount of each raw material added, and the polymerization conditions were changed as described in Table 3. Extruded foam of the aromatic aromatic hydrocarbon polymer compositions u to z and ab, ac and a disk container for web strength test. The methyl methacrylate used in Table 3 was manufactured by Asahi Kasei Chemicals Co., Ltd., a butyl acrylate-based East Asian synthesis system, an α-methylstyrene dimerization system, and a Wako Pure Chemical Industries. However, in Comparative Examples 6 and 10, 11, since the elongational viscosity of the vinyl aromatic hydrocarbon polymer composition was too low, foaming occurred during extrusion foaming, and the extruded foamed sheet could not be produced. The physical properties and the like are shown in Table 5.

[Comparative Example 8]

Three 5L-7L-7L laminar flow reactors 3 equipped with a mixer were connected in series, and then a vinyl aromatic hydrocarbon as shown in Table 4 was produced using a polymerization apparatus equipped with a two-axis extruder equipped with two-stage exhaust gas. Polymer composition aa. That is, 90 parts by mass of styrene, 5 parts by mass of the linear vinyl aromatic hydrocarbon polymer B-8 described in Table 1, 5 parts by mass of ethylbenzene, 1,1-bis(t-butylperoxy)cyclohexane The alkane (in Table 4, abbreviated as "PHC". The same applies to Tables 2 to 3.) 0.04 parts by mass of the raw material solution was supplied to a polymerization machine for polymerization. The first stage polymerization machine was rotated at 120 ° C, 30 rpm, and polymerized for 2 hours to precipitate rubber particles. The polymerization was continued at 135 ° C for 3 hours in the second stage polymerization machine to stabilize the rubber particles, and then further polymerized in the third stage. The polymerization was carried out at 145 ° C for 3 hours, and the final polymerization solid content was 69%. The polymerization solution was devolatilized by a uniaxial extruder equipped with a three-stage exhaust gas at 220 ° C and 2.666 kPa. The vinyl aromatic hydrocarbon polymer composition aa of Example 8. When the extruded foamed sheet is formed in the same manner as in Comparative Example 1 when the vinyl aromatic hydrocarbon polymer composition aa is to be used, since the elongational viscosity of the vinyl aromatic hydrocarbon polymer composition aa is too low, extrusion is carried out. When foaming occurs, foaming occurs, and the extruded foam sheet cannot be formed. The physical properties and the like are shown in Table 5.

[Comparative Example 9]

5 parts by mass of the block copolymer B-1 described in Table 1 and 95 parts by mass of PS japan polystyrene G9305 (melt flow rate = 1.5 g/10 min) were extruded using a two-axis manufactured by Toshiba Machine Co., Ltd. The machine (TEM26SS-12-2V) was granulated at 220 ° C and 150 rpm to produce an extruded foamed sheet of the vinyl aromatic hydrocarbon polymer composition ad of Comparative Example 9 and a disk container for web strength test. The physical properties and the like are shown in Table 5. In addition, the vinyl aromatic hydrocarbon polymer composition ad of the present example is formed by simply mixing polystyrene and a block copolymer, and does not form a conjugated diene compound unit of the block copolymer. A high molecular weight component that is the starting point. That is, this form cannot be obtained. The desired branched vinyl aromatic hydrocarbon polymer (B).

[Examples 11 to 19]

[Manufacture of vinyl aromatic hydrocarbon polymer composition i to s]

The vinyl aromatic hydrocarbon polymers of Examples 11 to 19 were produced in the same manner as in Example 1 except that the types, the amounts of addition, and the polymerization conditions of the block copolymer were changed as described in Table 2. Composition i to s. The physical properties and the like are shown in Table 6.

[Plate-like foam extrusion of vinyl aromatic hydrocarbon polymer composition]

a vinyl aromatic hydrocarbon polymer composition, which is formed by using a uniaxial extruder, a mixer, a rotary cooler, and a mold, and is 100 parts by mass relative to the vinyl aromatic hydrocarbon polymer composition. 1 part by mass of talc as a foaming nucleating agent and 3 parts by mass of hexabromocyclododecane were added, and a thermal stabilizer was further added to prepare a plate-like extruded foam having a thickness of 30 mm. The temperature of the molten region of the resin is adjusted to be 180 to 200 ° C, the rotary cooler temperature is 150 to 160 ° C, and the mold temperature is 120 to 130 ° C. The foaming nucleating agent was made of Mistron, Japan, and Mistron Vapor, and LPG (n-butane/isobutane = 70/30 < volume fraction>) was used for the foaming agent. The thus obtained plate-like extruded foams of Examples 11 to 19 were subjected to measurement of foam density, closed cell ratio, and compressive strength. The results of these are shown in Table 6.

[Examples 20 to 22]

The plate-like extruded foam was produced in the same manner as in Examples 11 to 19 using the vinyl aromatic hydrocarbon polymer compositions h, q to r prepared in Examples 8 to 10. The physical properties and the like are shown in Table 6.

[Comparative Examples 12 to 16]

The vinyl aromatic hydrocarbon polymer of Comparative Examples 12 to 16 was produced in the same manner as in Comparative Example 1, except that the type, the amount of each addition, and the polymerization conditions of the block copolymer were changed as described in Table 3. Compositions t to z. The plate-like extruded foams of Comparative Examples 12 to 16 were produced in the same manner as in Examples 11 to 19 using the vinyl aromatic hydrocarbon polymer compositions t to z. The physical properties and the like are shown in Table 6.

[Comparative Example 17]

The vinyl aromatic hydrocarbon polymer composition aa produced in Comparative Example 8 was used to form a plate-like extruded foam in the same manner as in Examples 11 to 19, due to the composition of the vinyl aromatic hydrocarbon polymer. The elongational viscosity of the material is too low, and foaming occurs during extrusion foaming, and it is impossible to form a sheet-like extruded foam. The results of Comparative Example 17 above are shown in Table 6.

[Comparative Example 18]

Using the vinyl aromatic hydrocarbon polymer composition ad prepared in Comparative Example 9, a plate-like extruded foam was produced in the same manner as in the cases of Examples 11 to 19. The physical properties and the like are shown in Table 6.

[Comparative Examples 19 to 20]

Using the vinyl aromatic hydrocarbon polymer compositions ab to ac prepared in Comparative Examples 10 to 11, the vinyl aromatic hydrocarbons were to be produced in the same manner as in Examples 11 to 19 in the form of a plate-like extruded foam. The elongational viscosity of the polymer composition is too low, and foaming occurs during extrusion foaming, and it is impossible to form a sheet-like extruded foam. The results of Comparative Examples 19 to 20 above are shown in Table 6.

In addition, in the above Table 1, the loading amount of styrene is referred to as "St amount", and the loading amount of 1,3-butadiene is expressed as "Bd amount", and is expressed as a content ratio.

In the above Tables 2 to 4, the 2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane is only referred to as "PTA", and 1,1-double (third Butylperoxy)cyclohexane is only referred to as "PHC".

As can be seen from Fig. 2, the vinyl aromatic hydrocarbon polymer compositions a to h and i to p used in Examples 1 to 8 and 11 to 20, The values of the tensile viscosity and workability (fluidity: melt flow rate) of s were relatively higher than those of the vinyl aromatic hydrocarbon polymer compositions t to aa and ad used in Comparative Examples 1 to 8 and 12 to 18. As can be seen from Fig. 3, the foamed extruded sheets of Examples 1 to 8 had higher values of both deep drawability and web strength than the foamed extruded sheets of Comparative Examples 1 to 8.

As can be seen from Fig. 4, the plate-like extruded foams of Examples 11 to 20 were compared with the plate-like extruded foams of Comparative Examples 12 to 18, and the values of the compressive strength in the same foam density were compared. high.

The present application is based on a Japanese patent application filed on Sep. 20, 2013 (Japanese Patent Application No. 2013-196187), and Japanese Patent Application No. 2013-196189, filed on Sep. The content of the content is used for reference.

[Industry use possibility]

The extruded foam of the present invention and the foamed cell of the container are easy to be subjected to molecular alignment and high strength, so that the excellent density of the foam and the strength of the product are balanced, and the secondary forming of the deep drawing container is performed. Very excellent in sex. Further, since the high expansion ratio can be achieved while maintaining high product strength, a foamed container excellent in product strength can be obtained with a small amount of material, which contributes to cost reduction of the product.

Claims (8)

An extruded foam comprising a vinyl aromatic hydrocarbon polymer composition comprising a linear vinyl aromatic hydrocarbon polymer (A) and a block copolymer of a vinyl aromatic hydrocarbon and a conjugated diene a branched vinyl aromatic hydrocarbon polymer (B) having a vinyl aromatic hydrocarbon chain bonded to a conjugated diene portion of the substance, wherein the above (A) and (B) contain a free choice of one vinyl aromatic group a homopolymer of a hydrocarbon or a copolymer of two or more vinyl aromatic hydrocarbons, a copolymer of a vinyl aromatic hydrocarbon and an unsaturated carboxylic acid, a vinyl aromatic hydrocarbon and an unsaturated carboxylic acid, and/or an unsaturated carboxylic acid a copolymer of an acid alkyl ester, and at least one of a group of a copolymer of a vinyl aromatic hydrocarbon and an unsaturated carboxylic anhydride or maleimide, and containing the following (a) The vinyl aromatic hydrocarbon polymer composition of (c): (a) the above (B) is branched starting from a conjugated diene compound unit in the block copolymer; (b) the aforementioned vinyl aromatic In the hydrocarbon polymer composition, the content of the block copolymer is 0.1% by mass or more based on the amount of the conjugated diene. (c) The above-mentioned vinyl aromatic hydrocarbon polymer composition is supplied to the Z average molecular weight before oxidative decomposition when oxidized and decomposed with tetrabutyl hydride as a catalyst using ruthenium tetroxide as a catalyst ( The ratio (Mz2/Mz1) of Mz1) to the Z average molecular weight (Mz2) after the oxidative decomposition is 0.30 or more and 0.90 or less. The extruded foam according to claim 1, wherein in the vinyl aromatic hydrocarbon polymer composition, the above (B) is dispersed in the above (A), and is enlarged by 100,000 times. In the electron micrograph, there are 0 to 1000 point particles having a particle diameter of 50 nm or less per 4 μm ² area. The extruded foam according to claim 1 or 2, wherein the vinyl aromatic hydrocarbon polymer composition has a tensile viscosity of 100,000 Pa·sec or more as measured at 200 ° C, 2500 Pa·sec. Million Pa‧sec below. The extruded foam according to claim 1, wherein the ratio of the Z average molecular weight (Mz) to the weight average molecular weight (Mw) of the vinyl aromatic hydrocarbon polymer composition is (Mz/Mw) 2.0 or more and 4.0 or less. The extruded foam according to claim 1, wherein the vinyl aromatic hydrocarbon polymer composition has a degree of branching of 0.30 or more and less than 0.90. The extruded foam according to the first aspect of the invention, wherein the vinyl aromatic hydrocarbon polymer composition has a molecular weight component of not less than 1,000,000 and not more than 20% by weight. The extruded foam according to the first aspect of the invention, wherein the amount of the component derived from the conjugated diene in the block copolymer is 5% by mass or more and 40% by mass or less, in the block copolymer. The amount of the component derived from the vinyl aromatic hydrocarbon is 60% by mass or more and 95% by mass or less, and the amount of the vinyl bond in the block copolymer is 7% or more and 70%. %the following. A container obtained by vacuum molding an extruded foam as described in claim 1 of the patent application.