JP2002337832A - Container molded of polystyrene resin laminated foamed sheet and molding method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a container molded of polystyrene resin laminated foamed sheet which scarcely transfers styrene dimer and styrene trimer to foods housed in the container. SOLUTION: The container is molded of a laminated foamed sheet which is made up by laminating a film made of a polystyrene resin composition at least to one side of a polystyrene resin foamed sheet with the aforementioned film laminate positioned at the inside of the container. The container molded of polystyrene resin laminated foamed sheet and its molding method have the following characteristics; (1) the polystyrene resin composition is a mixture of polystyrene resin and styrene rubber, (2) the amount of rubber component in the polystyrene resin composition is 1-30 wt.%, (3) the amount of styrene dimer and styrene trimer included in the aforementioned film laminate is 1000 ppm or below, (4) the gradient at the side of the container is 8 deg. or below, (5) the depth of the container is 120 mm or below, and (6) the difference between the maximum thickness and the minimum thickness at the side of the container is 0.5 mm or below.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

2. Description of the Related Art Foamed polystyrene resin sheets are used after being molded into various shapes due to their excellent thermoformability. In addition, the molded body obtained by thermoforming is excellent in rigidity, lightness, heat insulation, appearance, and inexpensive reasons,
Widely used as food containers, mainly instant noodles. However, in recent years, it has become clear that low molecular weight components such as styrene oligomers such as styrene dimer and styrene trimer may migrate to foods from containers made of polystyrene resin foam sheet. Research results showing that these styrene dimers and styrene trimers are not harmful to the human body have been published. However, such a low molecular weight component has a strong aversion to the transfer to the food, and a reduction in the amount of the transfer component from the food container to the food is strongly desired.

On the other hand, in a molded container made of a polystyrene resin foam sheet, the inside of the container is prevented in order to prevent damage to the container due to contact between the food filled therein and the inner wall of the container and sticking of chopsticks and forks into the molded container during use. There is a laminate of film layers made of high impact polystyrene (hereinafter, referred to as HIPS). HIP inside such a container
There is also a demand for reducing the amount of the low molecular weight component transferred to food as described above even in a container in which S is laminated.

[0003] Among them, a multilayer structure is disclosed (Japanese Patent Application Laid-Open No. 2000-218742) in which a resin having a specific composition is laminated on a polystyrene resin foam to reduce the transfer of styrene oligomers to food. I have. However, when such a special resin is used, there is a problem of an increase in cost due to an increase in raw material cost, introduction of a manufacturing facility for the resin, an increase in steps, and the like. Also, it is not enough to achieve a high level of elution reduction. Further, the elution amount may not be reduced depending on the shape of the container or the molding conditions of the container.

[0004]

DISCLOSURE OF THE INVENTION The present invention is intended to reduce the amount of styrene dimer and styrene trimer transferred to food, and to damage the container due to contact between the food filled therein and the inner wall of the container, and to reduce the use of chopsticks and forks during use. An object of the present invention is to provide an inexpensive polystyrene-based resin laminated foam sheet molded container in which piercing of the container is prevented.

[0005]

When the polystyrene resin laminated foam sheet is heated and then molded in a mold, the heated polystyrene resin laminated foam sheet is stretched, cooled and solidified in a mold, and shaped into a container. Molded into At this time, the film layer disposed inside the container receives stretching and stress, and due to the stretching and stress, an extremely small number of crazes are generated in the film layer.

[0006] The craze of a laminated film is micro-deformation that occurs in a polymer when stress is concentrated on the laminated film, and occurs in a direction perpendicular to the stress. And
It propagates through the resin layer and grows and propagates throughout the matrix. Eventually, when the molecular flux in the craze is cut, it is converted into a crack and destroyed. In other words, craze is a pioneer in brittle fracture. This craze is composed of a molecular bundle in which polymer molecules are oriented and voids between them (reference: Shin-Polymer Bunko, Fumio Ide, impact polymer material (upper) (lower). From this void, polystyrene resin lamination Styrene dimer contained in foam sheet,
And styrene trimer is considered to elute.

As a result, it is considered that when hot water or a test solvent is filled in the container, the craze promotes the elution of the styrene dimer trimer, and the amount of the elution increases. In particular, in the case of a laminated foamed sheet in which the film layer is made of a resin composition in which a styrene-based rubber is mixed with a polystyrene-based resin, increasing the stretching / stress during molding of the container increases the craze of the film layer, and the amount of elution increases rapidly. Significant increase is seen. On the other hand, when a container is formed from a laminated polystyrene resin foam sheet, the stretching and stress are large at the corners of the container side and the container bottom, and the above-mentioned craze is generated more frequently than at other parts of the container. From these facts, in the molded container of the polystyrene resin laminated foam sheet, if the inclination of the container side is too large or the container depth is too large, the stretching and stress will increase, the occurrence of craze will increase, and the elution will occur. The amount was found to increase significantly.

[0008] Further, when there is uneven thickness (thickness unevenness) on the container side of the molded container, the elution amount may increase.
The deviation in the thickness of the container side portion is caused by the deviation in the stretching and stress during molding. In such a case, stretching of the container side
A portion having a large stress has more craze than a portion having a small stretching / stress, and as a result, the amount of elution of the molding container is large. In other words, it was found that when the thickness deviation was too large at the side of the molded container after molding, the amount of elution of the molded container increased.

As described above, in a molded container using a polystyrene resin laminated foam sheet in which a mixed resin containing a specific amount of an oligomer composed of a polystyrene resin and a styrene rubber is laminated, the container is formed into a specific shape. As a result, they have found that they are effective in reducing the amount of low-molecular-weight components such as styrene-based oligomers transferred to foods, and have completed the present invention.

That is, the present invention provides (1) a polystyrene resin laminated foam sheet in which a film layer made of a polystyrene resin composition is laminated on at least one surface of a polystyrene resin foam sheet, wherein at least the film layer is provided inside the container. A polystyrene-based resin laminated foam sheet molded container obtained by molding so as to be arranged, wherein the polystyrene-based resin composition comprises a mixture of a polystyrene-based resin and a styrene-based rubber; Rubber component amount of 1-3
0 wt%, the content of the styrene dimer and styrene trimer in the film layer is 1000 ppm or less, the inclination of the container side is 8.0 or less, the container depth is 120 mm or less, and the difference between the maximum thickness and the minimum thickness at the container side is 0. 5m
The polystyrene-based resin-laminated foam sheet molding container (Claim 1), wherein the amount of styrene dimer and styrene trimer eluted into heptane is 1000 ppb or less. A resin-laminated foam sheet molding container (Claim 2), and (3) after heating the polystyrene-based resin laminated foam sheet in a heating furnace,
2. The polystyrene resin laminate according to claim 1, wherein the mold is molded in a mold having a clearance of 30 to 90% of a secondary thickness of the laminated foamed sheet. The present invention relates to a method for molding a foamed sheet molded container (Claim 3).

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The present invention provides a polystyrene resin foam sheet obtained by heating and molding a polystyrene resin foam sheet obtained by laminating a resin comprising a mixture of a polystyrene resin and a styrene rubber on at least one surface of a polystyrene resin foam sheet. For containers.

The polystyrene resin foam sheet used in the present invention can be any polystyrene resin foam sheet known to those skilled in the art. For example, an extruded foam sheet obtained by melt-kneading a polystyrene-based resin and a foaming agent in an extruder and extruding from the extruder to foam.

The polystyrene-based resin used for the polystyrene-based resin foam sheet is not particularly limited. For example, HIPS (graft polymer of styrene-butadiene copolymer and styrene), styrene homopolymer, p-methylstyrene Homopolymer, styrene-maleic anhydride copolymer, styrene-acrylonitrile copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-butadiene copolymer, styrene-butadiene-acrylonitrile copolymer Any one of a coalescence, a mixture with polystyrene polyphenylene oxide, and the like, or a combination thereof. In particular, a styrene homopolymer is preferable from the viewpoint of recyclability.

As the foaming agent, a volatile foaming agent, an inorganic gas-based foaming agent, a decomposition type foaming agent and the like are used. Examples of the volatile blowing agent include trichlorofluoromethane, dichlorofluoromethane, chlorodifluoromethane, S-dichlorotetrafluoroethane, propane, butane, pentane and the like. Examples of the inorganic gas-based blowing agent include an inert gas such as carbon dioxide, nitrogen, and air. As decomposition type foaming agents, azodicarbonamide, dinitrosopentamethylenetetramine, azobisisobutylnitrile,
And sodium bicarbonate. Any one of them or a combination of two or more thereof may be used.

The polystyrene resin foam sheet may be used, if necessary, with a nucleating agent such as talc, a modifier such as an antistatic agent or a lubricant, a stabilizer such as a phenolic antioxidant or vitamin E, and a coloring agent. , An ultraviolet absorber, a filler, and a flame retardant.

In the present invention, the polystyrene resin and the styrene rubber constituting the resin composition laminated on the inside of the container are preferably those produced by suspension polymerization or solution polymerization, and the others are not particularly limited. .

The polystyrene-based resin may be a copolymer as long as the effect of the present invention is not impaired, provided that styrene is contained in an amount of 50% by weight or more. As the copolymer component,
Conjugated dienes such as 1,3-butadiene and isoprene, α
Styrene derivatives such as methylstyrene, paramethylstyrene, t-butylstyrene and chlorostyrene; esters of acrylic acid and methacrylic acid such as methyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate and cetyl methacrylate, or acrylonitrile and dimethyl fuma And various monomers such as ethyl fumarate, and these monomers can be used alone or in combination of two or more.
Further, bifunctional monomers such as divinylbenzene and alkylene glycol dimethacrylate may be used in combination. Such materials include polystyrene, which is a styrene homopolymer, and HIP, which is a copolymer with 1,3-butadiene.
S is preferred in terms of balance between heat resistance, mechanical properties such as impact resistance and rigidity, and cost.

The weight average molecular weight of such a polystyrene resin is preferably from 200,000 to 500,000, more preferably from 250,000 to 450,000. If the weight average molecular weight is less than 200,000, the obtained laminated resin becomes brittle, which is not preferable. On the other hand, if the weight average molecular weight exceeds 450,000, the processability during lamination decreases. As a method for polymerizing a polystyrene resin, suspension polymerization is preferred in terms of cost.

The styrene rubber used as a resin for the film layer by mixing with the polystyrene resin is as follows.
Styrene-butadiene block copolymer, styrene-isoprene block copolymer, styrene-ethylene / butylene block copolymer and the like can be mentioned. They may be used alone or in combination of two or more. Among these, polystyrene, which is the base resin of the polystyrene resin foam sheet, has a great effect of preventing damage to the container due to contact between the food filled therein and the inner wall of the container and sticking of chopsticks and forks into the molded container during use. A styrene-butadiene block copolymer is preferred from the viewpoints of adhesion to a system resin and cost. The styrene-butadiene block copolymer can be polymerized by solution polymerization (living anion polymerization method) using an alkali-based initiator. Note that styrene, as long as the effects of the present invention are not impaired,
1,3-pentadiene as a monomer other than butadiene,
A conjugated diene such as isoprene may be used.

Styrene rubber at 200 ° C., load 5 kgf
Is preferably in the range of 5 to 30, and the rubber component content is 30 to 9
0% by weight is preferred. Styrene-based rubber outside this range has poor dispersibility in polystyrene-based resin, and has the effect of preventing damage to the container due to the contact of the food filled with it with the inner wall of the container and sticking of chopsticks and forks into the molded container during use. It is hard to be.

The resin composition of the film layer constituting the laminated polystyrene resin foam sheet of the present invention comprises a mixture of a polystyrene resin and a styrene rubber, and the total rubber component content in the resin composition is preferably 1 to 1. It is characterized by being 30% by weight, more preferably 2 to 15% by weight.
When the total rubber component amount is less than 1% by weight, it is difficult to obtain the effect of preventing damage to the container due to the contact of the food filled therein with the inner wall of the container and the sticking of chopsticks and forks into the molded container during use. If it exceeds, laminating processability deteriorates.

The film layer resin composition thus obtained can be laminated in a film state on the above-mentioned foamed polystyrene resin sheet by various methods. The total content of dimer and styrene trimer is preferably 100
0 ppm or less, more preferably 800 ppm or less. If it exceeds 1,000 ppm, it will be difficult to significantly reduce the amount of styrene dimer and styrene trimer eluted from the container for forming a foamed polystyrene resin sheet obtained from the resin composition for the film layer.

The method for laminating the laminated resin composition of the present invention on at least one surface of the polystyrene resin foam sheet is not particularly limited. For example, a method of adhering to a foamed sheet to which a resin composition previously formed into a film shape is supplied by a hot roll or the like, and a method of adhering to a foamed sheet to which a resin composition previously formed into a film shape is supplied via an adhesive. And a method in which a film layer resin composition supplied from an extruder is laminated on a supplied foam sheet in a film shape and fixed by a cooling roll or the like. Above all, the method of laminating and fixing the laminated resin composition supplied from the extruder in a film shape is preferable in terms of the number of manufacturing steps and the cost.

Further, a stabilizer, a colorant, an antistatic agent, a filler, a lubricant and the like may be added to the film layer resin composition of the present invention as long as the effects of the present invention are not impaired.

The polystyrene resin laminated foam sheet molded container of the present invention can be manufactured by vacuum / pressure molding. In particular, molding using a male-female fitting mold is preferable in terms of mold determination.

The polystyrene-based resin laminated foam sheet molded container of the present invention is characterized in that the inclination of the container side portion is preferably 8.0 or less, more preferably 7.0 or less. The container side inclination is measured by the following method (FIG. 1). When the container shape is circular, when the diameter of the container bottom is set to a1 mm, the container diameter is set to b1 mm, and the container depth is set to c1 mm, the container side inclination e1 is given by the following formula (1) e1 = c1 / ((b1-a1) / 2) (1) When the container shape is a rectangle, the container side inclination on the long side of the rectangle and the container side inclination on the short side are obtained, and the larger value is adopted as the container side inclination. The inclination of the bottom of the long side of the rectangle is a2
mm, when the length of the mouth side on the long side is b2 mm and the depth of the container is c2 mm, the following equation (2) e2 = c2 / ((b2-a2) / 2) (2) If the bottom side length is a3 mm and the mouth side length at the short side is b3 mm, it is expressed by the following equation (3).

E3 = c2 / ((b3-a3) / 2) (3) When the inclination of the container side is larger than 8.0, the styrene dimer from the container obtained from the polystyrene resin laminated foam sheet And it becomes difficult to greatly reduce the elution amount of the styrene trimer.

The polystyrene resin laminated foam sheet container of the present invention has a container depth of 120 mm or less, preferably 1 mm or less.
It is characterized by being not more than 00 mm. If it is larger than 120 mm, it will be difficult to significantly reduce the amount of styrene dimer and styrene trimer eluted from the container obtained from the polystyrene resin laminated foam sheet.

The polystyrene resin laminated foam sheet molded container of the present invention is characterized in that the difference between the maximum thickness and the minimum thickness at the container side is 0.5 mm or less, preferably 0.4 mm or less. The difference between the maximum thickness and the minimum thickness of the container side is measured by cutting the container and measuring the thickness of the container side at intervals of 5 mm in the depth direction using a loupe with memory (loupe manufactured by peak × 10). Obtained by calculating the difference between the minimum values. The difference between the maximum thickness and the minimum thickness can be adjusted by changing the timing of closing the male and female molds, the timing of evacuation in the molds, the surface roughness of the molds, and the like. . If the difference between the maximum thickness and the minimum thickness is larger than 0.5 mm, it will be difficult to greatly reduce the amount of styrene dimer and styrene trimer eluted from the container obtained from the polystyrene resin laminated foam sheet.

In the present invention, when the polystyrene resin laminated foam sheet is heated in a heating furnace and then molded by a molding die,
The clearance of the mold is from 30% to 90%, preferably from 40% to 8%, of the secondary thickness of the laminated foam sheet when heated.
It is characterized in that it is molded in a mold of 0% or less. In a polystyrene-based resin laminated foamed sheet, foaming is caused by heating at the time of molding and the thickness is increased (foaming by heating is 2
Secondary foaming, the thickness after secondary foaming is referred to as secondary thickness). When performing container molding, molding may be performed using a mold having a clearance smaller than the secondary thickness in order to improve the mold definition. At that time, the laminated foamed sheet receives stress by being molded in a mold having a clearance smaller than the thickness of the laminated foamed sheet. When the stress is large, the stress applied to the laminated foamed sheet increases, and as a result, the amount of styrene dimer / styrene trimer eluted in the obtained molded container tends to increase. When the mold clearance is 30% or less of the secondary thickness of the laminated foamed sheet, it is difficult to greatly reduce the amount of styrene dimer and styrene trimer eluted from a container obtained from the polystyrene-based resin laminated foamed sheet. When the mold clearance is 90% or more of the secondary thickness of the laminated foamed sheet, the mold rule may be poor and the appearance of the container may be poor.

The present invention relates to a method for molding a polystyrene resin laminated foamed sheet in a heating mold after heating the foamed sheet in a heating furnace.
It is preferable to mold with a mold whose surface temperature is controlled to be 60 ° C. or more and 120 ° C. or less. When the mold temperature is lower than 60 ° C., the cooling and the stretching of the laminated foamed sheet are simultaneously performed by the mold, and as a result, the stress applied to the laminated foamed sheet may increase and the amount of elution may increase. When the mold temperature is higher than 120 ° C., the deformation of the container during cooling after the mold is released may become large.

The amount of styrene dimer and styrene trimer eluted from the thus obtained polystyrene resin laminated foam sheet container is extremely small, and is preferably 1000 ppb or less, more preferably 800 ppb or less in heptane.

[0033]

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. [Measurement of Styrene Dimer and Styrene Trimer] The laminated resin composition film or the laminated foamed sheet was dissolved in chloroform and measured by GC. GC: GC-5890 Series 2 manufactured by Hewlett-Packard Column: DB-5 / manufactured by J & WS Scientific
0.25 mmi. d. × 30 m Film thickness 0.25 μm Column temperature: 40 ° C. (0.5 min) → 10 ° C./min→100
° C → 20 ° C / min → 280 ° C (15 minutes) Detector: FID [Measurement of the dissolution amount of styrene dimer and styrene trimer] It was measured according to the regulations.
Heptane was put in a polystyrene resin laminated foam sheet container, left at 25 ° C. for 60 minutes, and the amounts of styrene dimer and styrene trimer in heptane were measured by GC / MS-SIM. GC / MS: HP6890 manufactured by Hewlett-Packard
Series 2 / HP5973. Column: DB-5 manufactured by J & W Scientific
MS 0.25 mmi. d. × 30 m thickness 0.25 micron. Column temperature: 40 ° C (0.5 min) → 10 ° C / min → 100
° C → 20 ° C / min → 280 ° C (15 minutes). (Example of producing polystyrene resin) A reactor equipped with a stirrer was charged with 8.00 kg of pure water and 1.05 kg of tribasic calcium phosphate.
kg, sodium dodecylbenzenesulfonate 46
g, 3.3 kg of sodium chloride, and stirred to form a water suspension. Then, to 8.00 kg of styrene, 1.33 kg of benzoyl peroxide, 1,1-bis-t as a polymerization initiator.
0.7 kg of -butylperoxy-3,3,5-trimethylcyclohexane was dissolved and added to the reactor, and the temperature was raised to 98 ° C., and polymerization was carried out for 4 hours. Next, the temperature was raised to 120 ° C., the temperature was maintained for 2 hours, and then cooled. The contents were taken out, dehydrated and dried to obtain a polystyrene resin. (Example 1) From the polystyrene resin obtained in the production example, the thickness was 1.9 mm, the expansion ratio was 8.5,
A foamed polystyrene resin sheet having 15 cells in the thickness direction was obtained. Next, a polystyrene-based resin obtained in the production example and a styrene-butadiene block copolymer (MI = 13, butadiene content 60% by weight) were mixed in an extruder equipped with a T-die in a ribbon blender at a mixing ratio of 90:10. By extruding it into a film on a polystyrene resin foam sheet fed at a linear speed of 19 m / min from a T-die, cooling, solidifying, and winding it up.
A 2.0 mm thick polystyrene resin laminated foam sheet having a 120 micron film layer was obtained. The laminated film portion of the obtained laminated foam sheet was cut out. After dissolving 0.5 g of the film sample in chloroform (reagent grade, manufactured by Kanto Chemical Co., Ltd.) and leaving it for 12 hours,
Injection into C gave a GC chromatogram. The peak areas of styrene dimer and styrene trimer were calculated from the GC chromatograph. Separately, calibration solutions (0.2 ppm, 1 ppm, 5 ppm, 10 p) of styrene dimer and styrene trimer samples obtained under the same GC measurement conditions
pm), a styrene dimer,
A calibration curve of the peak area and the content of the styrene trimer was obtained. The content of styrene dimer and styrene trimer in the film portion is obtained by calculating the styrene dimer and styrene trimer content of the film sample from the peak area of the styrene dimer and styrene trimer in the GC chromatogram of the film sample and the calibration curve. Was.

Next, the foamed sheet laminated with the polystyrene resin was heated in a furnace at 162 ° C. for 20 seconds using a small single-shot molding machine such that the film layer was inside the container. A male-female fitting mold having a clearance of 2.0 mm and a male-female fitting having a diameter of 150 mm, a bottom diameter of 130 mm, and a depth of 60 mm was molded. The molding conditions of the mold at this time were such that the male mold was molded with a press delay of 1 second and the female mold was molded with a press delay of 1.5 seconds. The term “press delay” as used herein refers to the time from when the polystyrene-based resin laminated foam sheet set in the compact molding machine starts to come out of the heating furnace until each mold closes. The amount of styrene dimer and styrene trimer eluted into heptane from the resulting molded container of laminated foamed polystyrene resin sheet was measured by gas chromatography. In addition, the secondary thickness of the polystyrene resin laminated foam sheet heated under the same conditions as when forming the container,
Table 1 shows the obtained maximum thickness and minimum thickness of the container side, and the measurement results of the amounts of styrene dimer and styrene trimer eluted from the container into heptane. (Example 2) A molded container was obtained in the same manner as in Example 1 except that the mixing ratio of the polystyrene resin and the styrene-butadiene block copolymer was mixed at 80:20. Table 1 shows the evaluation results. (Embodiment 3) The mold clearance is 2.0 mm.
A molded container was obtained in the same manner as in Example 2 except that a container having a mouth size of 140 × 140 mm, a bottom size of 115 × 115 mm, and a depth of 60 mm was molded using the male-female fitting die. Table 1 shows the evaluation results. (Example 4) A molded container was obtained in the same manner as in Example 2 except that the mold clearance was set to 1.2 mm. Table 1 shows the evaluation results. (Comparative Example 1) A laminated foamed sheet was obtained in the same manner as in Example 1, except that the mixing ratio of the polystyrene resin and the styrene-butadiene block copolymer was mixed at 40:60. The elongation when the film layer resin composition was extruded from the T-die into a film on a foamed sheet was uneven, and an acceptable laminated foamed sheet was not obtained. (Comparative Example 2) A method similar to that of Example 1 was used except that a HIPS resin (MI = 2, rubber content 7% by weight) was used instead of the mixed resin of the polystyrene resin and the styrene-butadiene block copolymer. A molded container was obtained. Table 1 shows the evaluation results. (Comparative Example 3) A male-female fitting mold having a mold clearance of 2.0 mm, a bore diameter of 150 mm, a bottom diameter of 140 mm, and a depth of 5
A molded container was obtained in the same manner as in Example 2 except that a 0 mm container was molded. Table 1 shows the evaluation results. (Comparative Example 4) A male-female fitting mold having a mold clearance of 2.0 mm, a mouth size of 160 x 160 mm, and a bottom size of 145.
A molded container was obtained in the same manner as in Example 2 except that a container having a size of 145 mm and a depth of 70 mm was molded. Table 1 shows the evaluation results. (Comparative Example 5) A molded container was obtained in the same manner as in Example 2, except that the male mold was molded with a press delay of 1.5 seconds and the female mold was molded with a press delay of 1.0 seconds. Table 1 shows the evaluation results.

[0035]

[Table 1]

[0036]

According to the present invention, it is possible to obtain an inexpensive polystyrene resin laminated foam sheet molded container in which the amount of styrene dimer and styrene trimer eluted from the container is greatly reduced.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a polystyrene-based resin laminated foam sheet molded container of the present invention.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 25/04 C08L 53:02 4J002 // (C08L 25/04 B29K 25:00 53:02) B29L 31: 56 B29K 25:00 B65D 1/00 B B29L 31:56 CF term (reference) 3E033 AA08 AA10 BA11 BA22 BB04 BB08 CA03 CA08 DA08 DD01 FA01 3E067 AB01 BA02A BA07A BB17A BB25A BC01A CA30 GD10 4F100 AK12B23B02A05B02B02E EJ02 EJ022 EJ42 EJ423 GB16 GB23 JK10 YY00B 4F202 AA13 AA13K AA47 AA47K AP11 AR12 CA17 CB01 CB21 CB26 CN01 CN05 4F208 AA13 AA13K AA47 AA47K AP11 AR12 MA06 MB01 MB21 MG04 MG1 BC1 BC02 BC03 BC02 BC031 GC00 GG00 GL00

Claims (3)

[Claims] 1. A polystyrene-based resin laminated foam sheet in which a film layer made of a polystyrene-based resin composition is laminated on at least one surface of a polystyrene-based resin foam sheet,
A polystyrene-based resin-laminated foam sheet molded container obtained by molding so that at least the film layer is disposed inside the container, wherein (1) the polystyrene-based resin composition comprises a polystyrene-based resin and a styrene-based rubber. (2) the amount of rubber component in the polystyrene resin composition is 1 to 30% by weight, and (3) the content of styrene dimer and styrene trimer in the film layer is 1000
ppm or less, (4) container side inclination is 8.0 or less, (5)
(6) A molded polystyrene resin laminated foam sheet container having a container depth of 120 mm or less, and (6) a difference between a maximum thickness and a minimum thickness at a container side portion of 0.5 mm or less. 2. The container according to claim 1, wherein the amount of styrene dimer and styrene trimer eluted into heptane is 1000 ppb or less. 3. When the polystyrene resin laminated foam sheet is heated in a heating furnace and then molded by a molding die, the clearance of the mold is 30 to 9 times the secondary thickness of the laminated foam sheet.
2. The method according to claim 1, wherein the mold is formed in a mold having a percentage of 0%.
A method for molding the polystyrene-based resin laminated foam sheet molding container according to the above.