JP2002331622A - Polystyrene resin laminated foamed sheet molded object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method object molded from a polystyrene resin composi tion and a laminated foamed sheet and hard to elute a styrene dimer or a styrene trimer to soup for instant noodles. SOLUTION: A laminated film of a polystyrene resin laminated foamed sheet is obtained by laminating a laminated film of a polystyrene resin composition consisting of a polystyrene resin and a styrene rubber on the polystyrene resin laminated foamed sheet. The laminated film is molded so as to become inside to obtain the polystyrene resin laminated foamed sheet molded object. The craze depth in the laminated sheet in the cross section of the molded object is not more than 80% of the thickness of the laminated sheet from the surface of the laminated sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded article made of a laminated polystyrene resin foam sheet.

[0002]

2. Description of the Related Art Foamed polystyrene resin sheets are excellent in thermoforming, and the resulting molded article has features such as beautiful appearance, light weight, and excellent heat insulating properties. In recent years, it has been used in large quantities. Instant noodle cups are also mainly made of polystyrene resin foam sheets. However, the polystyrene-based resin sheet contains a styrene dimer and a styrene trimer, which are said to be suspected to be environmental hormones in part, and has a drawback that it is eluted into instant noodle soup.
In particular, cracks (punching processability) during molding of molded products, generation of fine powder due to contact between noodles and the inner wall of molded products during product transportation,
For the purpose of preventing holes from being pierced by chopsticks, etc., the so-called laminated foamed sheet molded product obtained by laminating a film made of high-impact polystyrene produced by bulk polymerization inside the molded product, the elution amount of styrene dimer and styrene trimer Is remarkably large. The mechanism by which the styrene dimer and styrene trimer elute into the instant noodle soup has not been elucidated, but it is speculated that the higher the styrene dimer and styrene trimer content in the resin, the greater the elution amount. Therefore, in order to reduce the amount of styrene dimer and trimer in the resin, high impact polystyrene produced by suspension polymerization may be used. In fact, compared to high-impact polystyrene produced by bulk polymerization, the amount of styrene dimer and styrene trimer eluted decreases in a laminated foamed sheet molded product obtained by laminating a film made of high-impact polystyrene produced by suspension polymerization. There is a tendency. However, the amount of styrene dimer and styrene trimer eluted cannot be sufficiently reduced.

[0003]

SUMMARY OF THE INVENTION According to the present invention, styrene dimer and styrene trimer are hardly eluted in instant noodle soup, and cracks (punching workability) during molding of the molded product.
It is an object of the present invention to obtain a molded article made of a polystyrene resin laminated foam sheet in which generation of fine powder due to contact between the noodles and the inner wall of the molded article during transportation of goods and perforation caused by sticking of chopsticks are prevented.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above problems, a polystyrene resin obtained by laminating a laminated film of a polystyrene resin composition comprising a polystyrene resin and a styrene rubber on a foamed polystyrene resin sheet. In the cross-section of a molded article formed by making the laminated film of the laminated foam sheet inside, a craze depth in the laminated film is 80% or less of the thickness of the laminated film from the surface of the laminated film. It has been found that the use thereof reduces the amount of styrene dimer and styrene trimer eluted into food soup, and the present invention has been completed.

That is, the present invention relates to a molding method in which a laminated film of a polystyrene-based resin composition formed by laminating a laminated film of a polystyrene-based resin composition comprising a polystyrene-based resin and a styrene-based rubber on a polystyrene-based resin foamed sheet is formed. The present invention relates to a molded article of a foamed polystyrene-based resin sheet, wherein the craze depth in the laminated film in the cross section of the molded article is 80% or less of the thickness of the laminated film from the surface of the laminated film.

The laminated film has a thickness of 50 to 200 μm.
m is preferable.

It is preferable that the polystyrene resin of the laminated film is produced by suspension polymerization.

[0008] It is preferable that the content of the styrene dimer and the styrene trimer contained in the polystyrene resin composition of the laminated film is 1300 ppm or less.

Preferably, the styrene rubber of the laminated film is a styrene-butadiene block copolymer.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a cross section of a molded article according to the present invention will be described. The shape of the mouth of the molded article formed by setting the laminated film of the polystyrene-based resin laminated foamed sheet inside is a rectangular shape as shown in FIG. 1A or a curved shape such as a circle as shown in FIG. There is. In the case of the rectangular shaped body 3 shown in FIG. 1, a surface (A-A plane) that appears when the shaped body 3 is cut along a diagonal line is defined as a shaped body cross section (b). In the case of the curved shaped body shown in FIG. 2, a plane (BB plane) that appears when the shaped body is cut through the center of the shaped body so that the cutting distance is maximized is defined as the shaped body cross section.

Next, the craze of the laminated film in the present invention will be described. 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. Then, it propagates through the resin layer and grows and propagates over the entire 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-resistant polymer material (upper) (lower)). It is considered that the styrene dimer and styrene trimer contained in the polystyrene-based resin laminated foam sheet elute from these voids.

The craze depth in the laminated film according to the present invention will be described with reference to FIG. The craze depth in the laminated film means the thickness of the region in the thickness direction where the craze 6 exists from the surface of the laminated film that is not in contact with the foam sheet (hereinafter, the laminated film surface 9).

The craze depth in the laminated film is 80% or less, preferably 50% or less, more preferably 30% or less of the thickness of the laminated film from the surface of the laminated film. If the craze depth is greater than 80%, the amount of styrene dimer and styrene trimer eluted into the instant noodle soup will increase.

Here, a method of measuring the craze depth in the laminated film will be described. A transmission electron microscope (JEOL JEM-1200EX) is used. Sections of the laminated film are stained by an OsO ₄ -stained ultrathin section method, observed with a transmission electron microscope, and photographed. From the photograph, a region where the craze exists from the surface of the laminated film in the cross section of the molded product is obtained.

The thickness of the laminated film is 50 to 200.
μm is preferred. More preferably, the lower limit is 7
0 μm, further 80 μm. The upper limit is 150 μm,
Further, the thickness is preferably 120 μm. If the thickness of the laminated film is smaller than 50 μm, the laminated film tends to have practical durability such as puncturing with chopsticks.
If it exceeds 00 μm, the production cost tends to increase, which is not preferable from the viewpoint of productivity.

As the polystyrene resin in the laminated film of the present invention, as long as the effects of the present invention are not impaired, a styrene homopolymer or styrene may be used.
It may be a copolymer of styrene containing not less than% by weight and a monomer copolymerizable with styrene. Copolymerization components include conjugated dienes such as 1,3-butadiene and isoprene, styrene derivatives such as α-methylstyrene, paramethylstyrene, t-butylstyrene and chlorostyrene; acrylic acid esters such as methyl acrylate and butyl acrylate Methacrylates such as methyl methacrylate, ethyl methacrylate, and cetyl methacrylate; or various monomers such as acrylonitrile, dimethyl fumarate, and ethyl fumarate;
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. As such a material, polystyrene which is a styrene homopolymer and high impact polystyrene which is a copolymer with 1,3-butadiene are preferable in balance of heat resistance, mechanical properties, cost and the like.

The lower limit of the weight average molecular weight of the polystyrene resin is preferably 200,000, more preferably 250,000, and the upper limit is preferably 500,000, more preferably 450,000. When the weight average molecular weight of the polystyrene resin is smaller than 200,000, the obtained laminated resin tends to be brittle. On the other hand, when the weight average molecular weight exceeds 500,000, workability at the time of lamination tends to decrease.

Examples of the method for polymerizing the polystyrene resin include ordinary polymerization methods such as bulk polymerization, suspension polymerization, and solution polymerization. Although not particularly limited, suspension polymerization is preferred in view of cost.

The total content of styrene dimer and styrene trimer in the polystyrene resin is usually 100
ppm or more, preferably 1300 ppm or less, more preferably 1000 ppm or less, even more preferably 800 ppm or less. When the content is 1300 ppm or more, the effect of the present invention that the amount of styrene dimer and styrene trimer eluted is extremely small tends to be insufficient.

The styrene rubber used in the present invention includes a styrene-butadiene block copolymer, a styrene-isoprene block copolymer, a styrene-ethylene
Butylene block copolymer and the like. Among them, cracking during molding (punching workability), generation of fine powder due to contact between the noodles and the inner wall of the molded body during transportation of goods, and prevention of perforations due to sticking of chopsticks, etc. are large, and the base material of the foamed sheet is large. A styrene-butadiene block copolymer is preferred from the viewpoints of adhesion to a polystyrene resin as a 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 conjugated dienes such as 1,3-pentadiene and isoprene may be used as monomers other than styrene and butadiene as long as the effects of the present invention are not impaired.

The styrenic rubber is preferably produced by suspension polymerization or solution polymerization, and is not particularly limited.

The styrene rubber is loaded at 200 ° C. under a load of 5 k.
The melt flow rate (hereinafter abbreviated as MFR) in gf is preferably in the range of 0.5 to 30, and the rubber component content is preferably in the range of 30 to 90% by weight. Styrene rubber out of this range tends to have poor dispersibility in polystyrene resin, cracking during molding (punching workability), generation of fine powder due to contact between noodles and the inner wall of the molding during transportation, and chopsticks Tends to be difficult to obtain the effect of preventing puncturing due to piercing.

The laminated film used in the present invention comprises the above-mentioned polystyrene resin and styrene rubber, and 75 to 99% by weight of the polystyrene resin and 1 to styrene rubber.
Preferably, the composition comprises 25% by weight. The lower limit of the amount of the polystyrene resin is more preferably 8
0% by weight. The upper limit is more preferably 95% by weight. The styrene rubber may be blended accordingly. When the blending amount of the polystyrene resin is less than 75% by weight, the effect of the present invention that the amount of styrene dimer and styrene trimer eluted is extremely small tends to be insufficient. On the other hand, if the amount of the polystyrene resin is more than 99% by weight, the laminated film is easily broken, which is not preferable.

The total amount of the rubber component (butadiene content) contained in the laminated film composition is preferably 1 to 15% by weight. More preferably, the lower limit is 2% by weight and the upper limit is 13% by weight. If the total rubber component amount is less than 1% by weight, cracking during film lamination or winding, cracking during container molding, generation of fine powder due to contact between the noodles and the inner wall of the container during transport of goods, perforation due to sticking of chopsticks, etc. The prevention effect tends to be difficult to obtain, and when it exceeds 15% by weight, the lamination processability tends to deteriorate.

The composition may contain additives such as an antioxidant, a filler, a lubricant, an antistatic agent and a coloring agent as long as the effects of the present invention are not impaired.

The amount of these additives varies depending on the type of additives to be added, but is not more than 1 part by weight, preferably not more than 0.5 part by weight, per 100 parts by weight of the composition.

The polystyrene-based resin foam sheet on which the laminated resin composition of the present invention is laminated has a polystyrene-based resin as a base resin, and is produced by ordinary extrusion foaming. The polystyrene resin used here is not particularly limited, and is produced by a usual polymerization method such as bulk polymerization, suspension polymerization, and solution polymerization. Among these, those obtained by suspension polymerization or solution polymerization are preferred in that the content of styrene dimer and styrene trimer is small.

The foaming agent used in the production of the polystyrene resin foam sheet includes cyclopentane, which is an alicyclic hydrocarbon, such as aliphatic hydrocarbons such as propane, butane, isobutane, pentane, isopentane, and hexane. Examples thereof include halogenated hydrocarbons such as cyclohexane such as methyl chloride, methylene chloride, dichlorofluoromethane, chlorofluoromethane, chlorodifluoromethane, trichlorofluoromethane, trichlorotrifluoroethane, and dichlorotetrafluoroethane. The amount of the foaming agent is 1
It is preferable to use 2 to 5 parts by weight with respect to 00 parts by weight.
These may be used alone or in combination of two or more, and may be added and impregnated at the time of producing a polystyrene resin, or may be added at the time of forming an extruded foam sheet. The expansion ratio is preferably 5 to 15 times. If the expansion ratio is less than 5, the moldability of the container may be poor. When the expansion ratio exceeds 15 times, the rigidity of the obtained container may be poor.

The nucleating agent used in producing the polystyrene resin foam sheet is not particularly limited.
Any nucleating agent that can be used may be used. Specific examples include inorganic compounds such as talc, calcium carbonate, barium sulfate, silica, titanium oxide, clay, aluminum oxide, bentonite, and diatomaceous earth, having an average particle size of 0.1 to 2
0 micron, preferably about 1 to 10 micron;
Organic acids such as citric acid, tartaric acid, and oxalic acid; and organic acids such as boric acid and bicarbonates or carbonates such as sodium, potassium, and ammonium. These nucleating agents are usually used alone, but may be used in combination of two or more. Of these,
Inorganic compounds such as talc, calcium carbonate, silica, and alumina are preferred because they are inexpensive and easy to handle. Further, the polystyrene resin foam sheet may contain a filler, a flame retardant, a coloring agent, an ultraviolet absorber, an antioxidant, and the like.

The foamed polystyrene resin sheet thus produced preferably has a thickness of 0.5 to 10 mm. When the thickness of the sheet is smaller than 0.5 mm, the rigidity of the sheet tends to be inferior, and when it exceeds 10 mm, the moldability of the container tends to be inferior. The number of bubbles in the thickness direction is preferably 5 / mm or more. 5 bubbles / mm
If it is smaller, the heat insulating property tends to be inferior.

The method of laminating the laminated film used in the present invention on the inside of the polystyrene resin foam sheet is not particularly limited. For example, a method in which a resin composition previously formed into a film shape is bonded to a supplied foam sheet by a hot roll or the like so as to be inside a formed body, and a resin composition previously formed into a film shape is supplied. A method of adhering to a foam sheet via an adhesive so as to be inside the molded body, and laminating the laminated resin composition supplied from the extruder to the supplied foam sheet in a layered manner so as to be inside the molded body. And a method in which the laminated resin in a plastic state is fixed with a cooling roll or the like. Above all, the method of laminating and fixing the laminated resin composition supplied from the extruder in a layered manner is preferable in terms of the number of production steps and the cost.

In the method of laminating and fixing the laminated resin composition supplied from the extruder in layers, a stabilizer may be added. By adding the stabilizer, the elongation of the laminated resin composition supplied from the extruder in the molten state is increased, and the laminated resin composition can be stably laminated and fixed in layers. Examples of the stabilizer include a phenolic antioxidant and a phosphorus processing heat stabilizer. Examples of phenolic antioxidants include n-octadecyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate and pentaerythrityl-tetrakis (3- (3,5-di-t-butyl- 4-hydroxyphenyl) propionate (available as Ciba Special Chemicals Co., Ltd., Irganox 1010), 2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2 (1- (2-hydroxy-
3,5-di-t-pentylphenyl) ethyl) -4,6
In addition to commercially available general substances such as -di-t-pentylphenyl acrylate and the like, vitamin C, vitamin E, catechin and the like particularly suitable for food use are also used. Above all, pentaerythrityl-tetrakis (3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate) is preferred from the viewpoint of the effect of improving the elongation of the laminated film resin upon melting. As a phosphorus-based processing heat stabilizer, tris (2,4-di-t-butylphenyl) phosphite (Ciba Special Chemicals Co., Ltd. I)
rgafos168), screws (2,4
Commercially available general compounds such as -bis (1,1-dimethylethyl) -6-methylphenyl) ethyl ester phosphorous acid can be used. Above all, tris (2,4-di-t-butylphenyl) phosphite is preferred from the viewpoint of the effect on the elongation of the laminated film resin during melting. Although the phenolic antioxidant and the phosphorus-based processing heat stabilizer can be used alone, the processability when laminating the laminated film resin composition on a polystyrene-based resin foam sheet and the styrene dimer and styrene trimer in food soup are described. It is preferable to use two kinds in combination because the amount of eluted is small. The addition amount of the stabilizer is preferably 0.01 to 0.5 part by weight based on 100 parts by weight of the mixture of the polystyrene resin and the styrene rubber. More preferably, the lower limit is 0.03 parts by weight, particularly 0.05 parts by weight. The upper limit is 0.4 parts by weight, more preferably 0.3 parts by weight. When the addition amount is less than 0.01 parts by weight, the lamination film resin composition tends to have poor elongation at the time of melting, and the lamination film resin is torn off during the production or lamination of the laminated resin film. Not preferred. Further, the effect of reducing the amount of styrene dimer and styrene trimer eluted into food soup tends to be small. Further, even when added in an amount of more than 0.5 parts by weight, there is a tendency that no further effect on the processability during lamination and the amount of styrene dimer and styrene trimer eluted into the food soup is seen, It is not preferable in terms of cost.

Using the polystyrene-based resin laminated foam sheet of the present invention, vacuum molding is performed in the same manner as in forming a normal foam sheet.
Various compacts can be manufactured by air pressure molding or the like. The amount of styrene dimer and styrene trimer eluted from the laminated foamed sheet molded product thus obtained is extremely small, and varies depending on the shape of the container to be molded, the molding method, and the like. The dissolution amount is preferably 500 ppb or less, more preferably 200 ppb or less, and can be used without any problem from the viewpoint of safety.

[0034]

EXAMPLES 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 Craze Depth in Laminated Film]
The measurement was based on the measurement of the craze depth in the laminated film described in the embodiment of the invention.

[Measurement of Styrene Dimer and Styrene Trimer Contents] A polystyrene resin was dissolved in chloroform and measured by GC. GC: Hewlett Packard GC-5890 Series II Column: J & W Scientific DB-5 0.25 mmi. d. × 30 m Film thickness 0.25 μm Column temperature: 40 ° C. (0.5 min) → 10 ° C./min→100
℃ → 20 ℃ / min → 280 ℃ (15min) Detector: FID

[Measurement of Dissolution Amount of Styrene Dimer and Styrene Trimer] The measurement was carried out in accordance with the Food Sanitation Law, the standards for packaging equipment and molded articles, and the method for preparing a test solution in a dissolution test.

Heptane was placed in a container of a molded article of a laminated foamed sheet of a polystyrene-based resin and allowed to stand at 25 ° C. for 60 minutes, and the amount of styrene dimer and styrene trimer in heptane was determined by G.
It was measured by C / MS-SIM.

The molded body has a diameter of 155 mm and a bottom diameter of 1
In the case of a truncated cone with an inner volume of 850 cm ³ of 40 mm and a depth of 50 mm, the required heptane amount is 580 cc.

In the case where the shape of the molded body is a trapezoidal cone of 150 mm on one side of the mouth, 110 mm on one side of the bottom and 60 mm in depth and having an internal volume of 1000 cm ³ , the necessary heptane amount is 800 cc.

GC / MS: manufactured by Hewlett-Packard
HP6890 series II / HP5973 column: DB-5 manufactured by J & W Scientific
MS 0.25 mmi. d. × 30 m film thickness 0.25 micron Column temperature: 40 ° C (0.5 min) → 10 ° C / min → 100
° C → 20 ° C / min → 280 ° C (15 minutes)

[Punching workability] When a molded product formed from a polystyrene-based resin laminated foamed sheet is punched out with a Thomson blade and taken out, a case where cracks occur in the punched portion is indicated by x.
(Fail), otherwise (good).

Production Example A reactor equipped with a stirrer was charged with 700 kg of pure water, 1.05 kg of tribasic calcium phosphate, 46 g of sodium dodecylbenzenesulfonate, and 3.3 kg of sodium chloride. As a polymerization initiator, 1.33 kg of benzoyl peroxide,
0.7 kg of 1,1-bis-t-butylperoxy-3,3,5-trimethylcyclohexane was dissolved, added to the reactor, and heated to 98 ° C., followed by polymerization for 4 hours. Then, the temperature was raised to 120 ° C. and maintained for 2 hours, followed by cooling.
The contents were taken out and dehydrated and dried to obtain a polystyrene resin having a total content of styrene dimer and styrene trimer of 600 ppm.

Examples 1 to 3 On the surface of a foamed sheet having a thickness of 2 mm, an expansion ratio of 8 and a number of 10 cells in the thickness direction produced by a usual method from the suspension-polymerized polystyrene resin obtained in the production example, Using a T-die, extrude a mixture of the suspension-polymerized polystyrene resin and the styrene-butadiene block copolymer obtained in the production example in a composition as shown in Table 1 (the type of each compounding agent is shown in Table 2).
A 20 micron film was laminated.

Next, the above-mentioned polystyrene-based resin laminated foam sheet was placed so that the laminated film was inside the molded body.
After heating the foamed sheet in a furnace at 150 ° C. for 13 to 15 seconds using a small single-shot molding machine for forming a polystyrene foam sheet, the diameter of the die was adjusted to 60 ° C. by a die having a diameter of 155 mm,
A compact having a bottom diameter of 140 mm and a depth of 50 mm was formed. The obtained molded body was punched out with a Thomson blade and taken out. The amount of styrene dimer and styrene trimer eluted into n-heptane from the obtained molded article of the laminated polystyrene-based resin foam sheet was measured by gas chromatography. The results of the formulation, craze depth in the laminated film, punchability of the molded product, and amount of elution are shown in Table 1 (the type of each compounding agent is shown in Table 2).

Example 4 The shape of the mold was 150 mm on one side of the mouth, 110 mm on one side of the bottom,
A laminated film, a laminated foamed sheet, and a molded article were produced in the same manner as in Example 1 except that a trapezoidal cone having a depth of 60 mm and an internal volume of 1000 cm ³ was formed. The results of the formulation, craze depth in the laminated film, punchability of the molded product, and amount of elution are shown in Table 1 (the type of each compounding agent is shown in Table 2).

Example 5 A laminated film, a laminated foamed sheet and a molded product were produced in the same manner as in Example 2 except that the thickness of the laminated film was changed to 100 μm. The results of the formulation, craze depth in the laminated film, punchability of the molded product, and amount of elution are shown in Table 1 (the type of each compounding agent is shown in Table 2).

Example 6 A laminated film and a laminated foamed sheet were produced in the same manner as in Example 1 except that the laminated film was produced from suspension-polymerized high-impact polystyrene. The results of the formulation, craze depth in the laminated film, punchability of the molded product, and amount of elution are shown in Table 1 (the type of each compounding agent is shown in Table 2).

COMPARATIVE EXAMPLE 1 A laminated film was prepared in the same manner as in Example 1 except that the suspension-polymerized polystyrene and the styrene-butadiene block copolymer obtained in the Production Example were blended as shown in Table 1 (types of the blending agents are shown in Table 2). In the same manner as in Example 1, a laminated film, a laminated foamed sheet and a molded article were produced. The results of the formulation, craze depth in the laminated film, punchability of the molded product, and amount of elution are shown in Table 1 (the type of each compounding agent is shown in Table 2).

Comparative Example 2 A laminated film, a laminated foamed sheet and a molded product were produced in the same manner as in Example 1 except that the laminated film was produced only from the suspension-polymerized polystyrene obtained in the production example.
The results of the formulation, craze depth in the laminated film, punchability of the molded product, and amount of elution are shown in Table 1 (the type of each compounding agent is shown in Table 2). While examining the punching property of the molded product, cracks occurred in the laminated film, and the molded product was not practical.

[0051]

[Table 1]

[0052]

[Table 2]

[0053]

According to the present invention, the amount of styrene dimer and styrene trimer eluted from the molded article can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a container formed of a sheet molded body of the present invention and the container.

FIG. 2 is a sectional view of another container made of the sheet molded body of the present invention and the container.

FIG. 3 is an electron micrograph showing craze in a cross section of a molded product.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 One side of mouth 2 One side of bottom 3 Molded object 4 Bottom diameter 5 Diameter 6 Craze 7 Rubber dispersed particles 8 Polystyrene resin 9 Laminated film surface

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) C08L 25/04 C08L 53/02 53/02 B65D 1/00 BF term (reference) 3E033 AA08 BA22 BB08 CA20 DA02 DD01 FA01 3E086 AB01 AD06 BA04 BA15 BA16 BB90 CA40 DA08 4F100 AK12A AK12B AK73B AL04B AL05B AN02B BA02 DA01 DJ01A GB16 4J002 BC021 BC031 BC041 BC051 BC061 BC071 BC081 BC091 BC111 BP012 GC00 GG00 GL00

Claims (5)

[Claims] 1. A molded article obtained by molding a laminated film of a polystyrene resin composition comprising a polystyrene resin and a styrene rubber, with a laminated film of a polystyrene resin laminated foam sheet laminated on a polystyrene resin foam sheet inside. A molded polystyrene resin foam sheet having a craze depth in the laminated film in a cross section of the molded article of 80% or less of the thickness of the laminated film from the surface of the laminated film. 2. The laminated film having a thickness of 50 to 200.
The polystyrene-based resin foamed laminated sheet molded article according to claim 1, which has a thickness of μm. 3. The polystyrene resin foam laminated sheet molded article according to claim 1, wherein the polystyrene resin of the laminated film is produced by suspension polymerization. 4. The content of styrene dimer and styrene trimer contained in the polystyrene resin composition of the laminated film is 1300 ppm or less.
4. A molded article of a foamed laminated polystyrene resin sheet according to item 2 or 3. 5. The styrene-based rubber is a styrene-butadiene block copolymer.
The molded article of the foamed polystyrene resin laminate according to the above.