JP2003236961A - Laminated foamed sheet of polypropylene resin and molded vessel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated foamed sheet of polypropylene resin which is free of problems such as drawdown and partial peeling of a film layer from a foamed layer and excellent in antistatic properties, and to provide a molded vessel which protects the contents from an impact in transport, reduces troubles of static electricity and is suitable for a package of an electronic component, by hot-molding the sheet. <P>SOLUTION: A biaxially oriented antistatic polypropylene resin film is laminated on a polypropylene resin foamed sheet of which the percentage of closed cells in a specified range of density is 40% or above. Thereby a resin laminated foamed sheet of which the surface resistivity is less than 10<SP>12</SP>Ω, the polypropylene resin laminated foamed sheet of which the heating shrinkage factor of the antistatic polypropylene resin film is 1.5-4.0%, and a hot-molded vessel thereof, are obtained. The resin used for the foamed sheet has preferably a melt tension in a specified range. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polypropylene resin laminated foam sheet and a thermoformed container thereof. More specifically, it is a foamed sheet with improved drawdown during thermoforming, which is a container obtained by thermoforming the sheet, and is excellent in surface appearance, cushioning property and antistatic property, especially for packaging electronic parts. The present invention relates to a foamed container having excellent protection performance as a container. In the present invention, the unit expressing the composition such as “part” is
Unless otherwise specified, it is expressed on a mass basis when the total of the resin components is 100 parts.

[0002]

2. Description of the Related Art When packaging electronic parts or the like, a foam having a cushioning property is used in order to prevent the product from being damaged by vibration or impact. However, such a foam is made of a thermoplastic resin and has high chargeability because it is an insulator, and the functions of electronic parts and the like are lost due to static electricity charged on the surface due to friction between packages and contents. A problem that causes
Further, when static electricity is charged on the surface of the packaging body, there is a problem that dust adheres to the surface of the packaging body and is unsuitable as a packaging body.

In order to solve such a problem, there is known a method of reducing the surface resistance value of the package to impart an antistatic property. For example, carbon is mixed at the time of molding the package, or the package is packaged. It is known to apply an antistatic agent to the surface. However, in the former method, the brittleness of the foam surface becomes high, and the packaging itself and the carbon powder are liable to be rubbed by the friction between the packaging and the contents due to vibration when the contents such as electronic parts are stored and transported. However, in the latter method, the antistatic agent applied during transportation migrates to the contents such as electronic parts and contaminates the contents. Therefore, there has been a demand for a package that improves these problems.

On the other hand, as a package having a cushioning property, there are containers such as trays formed by thermoforming various thermoplastic resin foam sheets. In general, various resin foam sheets are shaped into a desired shape by a so-called "thermoforming" in which a sheet is heated and brought into close contact with a mold by vacuum or compressed air to form a container. The polypropylene-based resin foam sheet has excellent properties such as cushioning, strength and heat resistance, and is used in the field of packaging of electronic parts, etc. Since the is a crystalline resin, the temperature dependence of the melt tension is large, and the tensile strength when heated to the molding temperature during the thermoforming becomes small, so that the sheet fixed by the clamp plate is There is a tendency for a large phenomenon called drawdown that hangs down in the direction of gravity. If this drawdown becomes large, the sheet will be easily wavy during molding, and wrinkles (bridges) will occur in the molded product, making it impossible to obtain a molded product with a good appearance. In a more extreme case, the sheet cannot contact the lower surface heater of the molding machine or the molding die, and molding cannot be performed.

Many attempts have been made to improve this point, and a molding method is, for example, Japanese Patent No. 28434.
According to Japanese Patent Laid-Open No. 74-74, an oven in which a heating zone has a closed shape except for an inlet and an outlet of a sheet is used, and a foamed PP sheet is gradually heated in a state where an atmospheric temperature in the oven is maintained in a temperature range of 155 ° C to 200 ° C. A method of raising the temperature is disclosed. However, in the disclosed molding method, the structure of the molding machine is special, and there is a possibility that the production cost may increase due to the equipment. Further, since the sheet heating is mainly the atmosphere heating, the heating time until the temperature is raised to the moldable temperature range becomes longer than that of the normal molding apparatus mainly using the radiant heating by the infrared heater. Therefore, in order to keep the molding cycle short, it is necessary to lengthen the heating zone, which is considered to be a problem in terms of productivity.

As another example, in Japanese Patent No. 2904337, for the purpose of obtaining a propylene-based resin foam sheet having excellent physical properties and appearance by using a conventional molding device, at least one surface of the foam sheet is It has been proposed to laminate an unfoamed or foamed propylene-based resin stretched film having a specific range of shrinkage stress. Compared to the foamed sheet alone, in the laminated foamed sheet, drawdown and corrugation of the sheet are improved to some extent in continuous molding of a container or the like, but it is possible to stably suppress the occurrence of bridging of the molded product. In some cases, the stretched film sometimes peeled off during thermoforming or during subsequent container storage.

In addition to the purpose of the above-mentioned patent, Japanese Patent Application Laid-Open No. 11-170455 discloses that in order to obtain mold adhesion and thermoforming uniformity when thermoforming a laminated foam sheet.
It has been proposed to laminate a polypropylene-based film having a specific tensile stress and elongation at break at 120 ° C. on a polypropylene-based resin foam sheet, which improves the mold adhesion and the like. It was not sufficient to eliminate partial peeling of the stretched film during storage in a container.

[0008]

SUMMARY OF THE INVENTION The object of the present invention is to overcome the above-mentioned problems and to eliminate the problems such as drawdown and partial peeling of the film layer and the foam layer by the usual continuous molding method. The purpose is to obtain a stable polypropylene-based resin laminated foam sheet with good antistatic properties, protect the contents from shocks such as vibrations or drops during transportation, and eliminate static electricity due to friction with the contents. It is intended to provide a laminated foam container suitable for a packaging body of electronic parts in which the laminated foam sheet is thermoformed, in which the above problem is suppressed.

[0009]

As a result of intensive studies, the present inventors have found that a polypropylene resin foam sheet having a relatively low expansion ratio has antistatic properties and a specific heat shrinkage under a specific temperature condition. By laminating a biaxially stretched polypropylene resin film having a ratio, a molded article such as a container having a stable surface appearance is obtained stably even by a normal continuous molding method, and a film layer is formed by thermoforming. The inventors have found that a molded product having good antistatic properties can be obtained without the foam layer being partially peeled off, and have completed the present invention.

That is, according to the present invention, the sheet density is 300 kg.
m ^-3 or more and 850 kgm ^-3 or less, the closed cell ratio is 40
% Or more, a biaxially stretched antistatic polypropylene resin film is laminated on at least one surface of a polypropylene resin foam sheet, and the polypropylene film has a surface resistivity of the film side sheet of less than 10 ¹² Ω. A resin laminated foam sheet, wherein the antistatic polypropylene resin film has a film winding direction and a width direction perpendicular to the film winding direction (hereinafter simply referred to as "width direction"), 1
When left at 50 ° C for 5 minutes, the heat shrinkage rate is 1.5 to
It is a polypropylene-based resin laminated foam sheet having a content of 4.0%. In addition, the polypropylene resin foam sheet is 20
High melt tension polypropylene resin (A) having a melt tension of 4.0 g or more at 0 ° C., or 50 parts or more of the component (A) and a linear crystalline polypropylene (B) as another component Is a polypropylene-based resin laminated foam sheet. The present invention also includes a laminated foam container obtained by thermoforming these laminated foam sheets.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. As described above, the present invention is a polypropylene-based resin obtained by laminating a biaxially stretched polypropylene-based resin film having specific heat-shrinking properties and antistatic properties on at least one surface of a polypropylene-based resin foam sheet having a specific density. A laminated foam sheet, which is a container formed by thermoforming the sheet.

In the present invention, the polypropylene-based resin foamed sheet means a foamed sheet containing polypropylene-based resin as a main component. The polypropylene resin is selected from homopolypropylene, a propylene random copolymer containing propylene and propylene as a main component (containing 60 mol% or more of a propylene component), a propylene block copolymer, and a propylene graft copolymer. Or a kind
A mixture of two or more kinds is used, but preferably, the high melt tension polypropylene resin (A) is used alone, or 50 parts or more of the component (A) and the linear crystalline polypropylene resin (B) are blended. The following resin composition is used.

High melt tension polypropylene resin (A)
Preferably has a melt tension at 200 ° C. of 4.0 g or more. If the resin has a melt tension of less than 4.0 g, the closed-cell rate of the foamed sheet formed into a film decreases, which causes a poor sheet appearance. Here, the melt tension at 200 ° C. is
Using a Capillograph manufactured by Toyo Seiki Co., Ltd., polypropylene was heated at 200 ° C. for 5 minutes to be melted in the barrel of the apparatus, and the melted polypropylene had a diameter of 2.095.
It is a tension when a strand having a length of 8 mm, a length of 8 mm and an L / D of 3.8 is extruded into the atmosphere at a rate of 15 mm / min to draw the strand at a rate of 2.0 m / min.

As the linear crystalline polypropylene resin (B), those commercially available as polypropylene in general can be used, and the melt index 10
It is preferably g / 10 minutes or less. For example, a polymer mainly composed of polypropylene such as a propylene homopolymer, a propylene-ethylene copolymer, a propylene-ethylene-diene copolymer is used. The melting point of the propylene homopolymer is 176 ° C. and the melting point of the copolymer is 135 ° C. to 160 ° C. It is desirable to use a high melting point in order to obtain a foam having excellent heat resistance. Further, a polypropylene resin as a main component may be mixed with another resin having a good miscibility as long as it is in a small amount, and examples of such a resin include polyethylene resin, ethylene vinyl acetate copolymer and the like. .

The polypropylene resin foamed sheet uses the high melt tension polypropylene resin (A) alone as the resin component, or contains 50 parts or more of the component (A) and has a linear chain as the remaining component. A compound containing the crystalline polypropylene (B) is preferable.
If the amount of the component (A) is less than 50 parts, the drawdown of the polypropylene-based resin foamed sheet becomes large, making it difficult to mold, and the foamed sheet has irregularities due to foam breakage, resulting in a poor appearance. Not preferable. or,
When the linear crystalline polypropylene (B) is used as the remaining component in addition to the component (A), the extrusion moldability of the foamed sheet is improved.

The density of the foamed polypropylene resin sheet of the present invention is 850Kgm ^-3 or less beyond the 300kgm ^-3. When the density is 300 kgm ^-3 or less, the closed cell rate of the foamed cells decreases, and the surface appearance of the molded product deteriorates even if molding is possible. Further, if the density exceeds 850 kgm ^-3 , sufficient buffering properties cannot be obtained. On the other hand, the closed cell rate of this foamed sheet is 40% or more. When the closed cell ratio is less than 40%, the drawdown becomes large, and at the time of thermoforming the laminated foam sheet laminated with the polypropylene resin film, partial peeling between both layers easily occurs.

The antistatic polypropylene resin film used in the present invention is a biaxially stretched film made of a resin composition prepared by mixing an antistatic agent with a polypropylene resin. Here, as the polypropylene resin, those commercially available as polypropylene in general can be used, and those having a melt index of 10 g / 10 minutes or less are preferable. For example, a propylene homopolymer, a random or block copolymer of propylene and an α-olefin such as ethylene other than propylene, 1-butene, 1-pentene, and 1-hexene, and further, these polymers may be mentioned. , Propylene homopolymer, propylene-
An ethylene random polymer and a block copolymer containing a polypropylene component and a propylene-ethylene random copolymer component are preferred. Further, it may be a mixture of polypropylene resin as a main component and other resin having a good miscibility in a small amount, and examples of such resin include polyethylene, ethylene vinyl acetate copolymer and the like.

As the antistatic agent to be blended with the polypropylene resin of the antistatic polypropylene resin film, when the film is laminated on the polypropylene resin foam sheet, the surface resistivity thereof is 10 ^-12 Ω. It is not particularly limited as long as it has an antistatic property such that it is less than less than, but quaternary ammonium salt, fatty acid polyhydric alcohol ester, polyoxyethylene adduct, polyethylene ester amide resin and the like are polypropylene. It is preferable in that it has a great effect of exhibiting antistatic properties when blended with a resin. The amount of the antistatic agent added to the polypropylene resin is preferably 2 parts or more. Compounding amount of antistatic agent is 2
If it is less than 10 parts, the antistatic property is insufficient and the surface resistivity of the sheet surface does not become less than 10 ¹² Ω, and the effect of preventing the generation of static electricity decreases, which is not preferable.

If desired, the resin composition of the film may contain known additives such as antifogging agents, antiblocking agents, antioxidants, crystal nucleating agents and lubricants.

On the other hand, this biaxially stretched antistatic polypropylene resin film is heat-shrinkable when left standing for 5 minutes at 150 ° C. in the winding direction of the film and the width direction of the film perpendicular thereto. The rate is 1.5-4.
It is necessary to be 0%, more preferably 1.8 to 3.8% or less, still more preferably 2.0 to 3.5% or less.

In the film, the higher the heat shrinkage, the finer the crystal structure of polypropylene and the better the surface gloss of the film, but the heat shrinkage is 4.0%.
If it is larger than the above range, the shapeability at the time of thermoforming is deteriorated, and the molding becomes difficult especially when a container having a large drawing ratio is formed, which is not preferable. On the other hand, if the heat shrinkage is less than 1.5%, the crystal becomes large and the surface gloss decreases. Furthermore, in order to obtain a good molded product with less wrinkles and uneven thickness, it is desirable that the ratio of the heat shrinkage ratios in the film winding direction and the film width direction be substantially the same.

The thickness of the antistatic polypropylene resin film of the present invention is not particularly limited, but in view of drawdown property and secondary moldability, it is 10 to 100.
The thickness is preferably μm, more preferably 15 to 80 μm. When the thickness of the polypropylene resin film is less than 10 μm, the effect of improving the drawdown property of the obtained laminated foam sheet is lowered, which is not preferable. On the other hand, the thickness of the polypropylene resin film is 1
When it is thicker than 00 μm, the secondary foamability (shapeability) of the obtained laminated foam sheet is deteriorated, which is not preferable.

The antistatic polypropylene resin film used in the present invention is within a range not impairing its effect.
It is possible to use a product that has been printed for decoration or applied with an adhesive for adhesion, while another resin layer is provided for the purpose of imparting adhesiveness, heat sealability, gas barrier property, etc. It is also possible to use a laminate.

As the method for producing the polypropylene resin film used in the present invention, there are a tenter method, a tubular inflation method and the like, and the former includes a sequential biaxial stretching method and a simultaneous biaxial stretching method. If the heat shrinkage ratio is in the range of 1.5 to 4.0%,
The stretching method is not particularly limited.

The polypropylene-based resin laminated foam sheet of the present invention has appropriate conditions set as long as the polypropylene-based resin foam sheet and the antistatic polypropylene-based resin film, which are the constituent elements, satisfy the requirements of the present invention. By the thermoforming, a container having a smooth surface, good shape accuracy, and sufficient cushioning property can be obtained.
Therefore, when the contents such as electronic parts are packed and conveyed by using the container, the contents have sufficient cushioning property to protect the contents from mechanical shock, and dust caused by rubbing against the contents caused by vibration during transportation. It is possible to suppress the occurrence of the occurrence of as much as possible, and to suppress the trouble of the contents due to it. When the surface resistivity of the laminated foamed sheet is less than 10 ¹² Ω, a container having excellent antistatic properties can be obtained by appropriately setting thermoforming conditions. Therefore, the contents such as the electronic parts can be protected from the electrical trouble due to the generation of static electricity during the carrying, which is excellent as a container for carrying the electronic parts.

Next, a method for manufacturing the polypropylene resin foam sheet of the present invention will be described. The polypropylene resin foam sheet of the present invention is obtained by extrusion molding a resin composition comprising a high melt tension polypropylene resin (A), a linear crystalline polypropylene resin (B) and a chemical foaming agent or a physical foaming agent. It is preferably produced by the method.

The method of mixing the high melt tension polypropylene-based resin (A) and the linear crystalline polypropylene-based resin (B) is not particularly limited, but the raw material stirred and mixed into the extruder at the time of forming the foamed sheet. May be directly added, or the raw materials mixed with stirring may be melt-mixed by a single-screw or twin-screw extruder to be pelletized, and then used for foaming extrusion.

As the chemical foaming agent, a mixture of sodium bicarbonate and citric acid can be preferably used. The method of adding the chemical foaming agent is not particularly limited, but a method of dry blending with the resin composition of the high melt tension polypropylene resin (A) and the linear crystalline polypropylene resin (B), or extrusion Either a method of using a quantitative feeder in a hopper of a machine or a method of preparing and adding a masterbatch based on a polyolefin resin such as polypropylene resin or polyethylene resin may be used.

The amount of the chemical foaming agent added is 0.1 to 1.5 parts by any method. If the amount added is less than 0.1 part, the desired expansion ratio cannot be obtained, and if it is added in excess of 1.5 parts, uniform dispersion and sufficient decomposition of the foaming agent in the extruder do not proceed, It is not preferable because a good foamed sheet cannot be obtained.

The physical foaming agent used in the present invention is carbon dioxide gas. Although butane and the like are used as the physical foaming agent, carbon dioxide gas is preferably used from the viewpoint of safety. As a method of adding the physical foaming agent, a method of supplying to the central zone of the twin-screw extruder or the central zone of the first-stage extruder of the tandem extruder,
A known method can be used.

The addition amount of the above-mentioned physical foaming agent is 1.
2 to 3.0 parts. If the amount added is less than 1.2 parts, the desired expansion ratio cannot be obtained, and if it exceeds 3.0 parts, the closed cell rate decreases, which is not preferable.

In the production of the foamed sheet of the present invention, an appropriate cell regulator, within the range that does not impair the physical properties of the foamed sheet,
Crosslinking agents, foaming aids, fillers, stabilizers, antioxidants, pigments and the like may be mixed.

The thickness of the polypropylene-based resin foam sheet is not particularly limited, but is 0.5 to 2.
It is preferably 5 mm. If the thickness of the polypropylene-based resin foam sheet is less than 0.5 mm, the resulting laminated foam sheet may have poor rigidity and heat insulation, which is not preferable.
On the other hand, if it is thicker than 2.5 mm, the preheating time for thermoforming becomes long and the productivity is lowered, which is not preferable.

The method for laminating the polypropylene resin film and the polypropylene resin foam sheet of the present invention is not particularly limited, and known methods such as extrusion laminating method and dry laminating method can be used.

The polypropylene resin laminated foam sheet of the present invention can be easily formed into various shapes by a known thermoforming method such as vacuum forming or pressure forming.

[0036]

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

The measuring methods used in the following examples and comparative examples were as follows. (Sheet Density) Mirage Trading Electronic Density Meter (MD
-200S). (Closed air bubble ratio) It measured based on ASTM: D-2856 using the air comparison type hydrometer by Tokyo science company. (Heat shrinkage ratio) 11 in Yamato Fine Oven
A 10 cm interval mark is drawn in the film winding direction (MD) and width direction (TD) on a film of 11 cm × 11 cm, and the film is left for 5 minutes in an oven at a set temperature of 150 ° C. The heat shrinkage rate was calculated by the following formula.

[0038]

[Formula 1]

(Drawdown Property) A 30 cm × 30 cm sheet was fixed in four directions with clamp plates using a vacuum single-shot molding machine manufactured by Asano Laboratory Co., Ltd., and a far-infrared heater (temperature: 500 ° C.) was used in the same manner as the ordinary sheet forming method. ), The deflection amount of the sheet at each heating time when the distance between the sheet and the upper and lower heaters was set to 100 mm, and the deflection amount of the sheet was measured by a laser displacement measuring machine manufactured by Keyence Corporation. The amount of deflection was used as the drawdown amount, and the drawdown property was evaluated. It is indicated that the larger this value is, the lower the moldability is. FIG. 1 shows a schematic view of the measuring device.

(Secondary Formability) With a vacuum forming machine (manufactured by Asano Laboratory Co., Ltd.), length 240 mm × width 160 mm × height 30 m.
Molding was performed on the container of m, and the moldability of the mold, the occurrence of bridges, and the appearance of the container were observed. As the evaluation criteria, ⊚ indicates that molding with good moldability and surface appearance could be carried out, △ indicates that molding with good surface quality was inferior but surface appearance was inferior, occurrence of bridges and decrease in surface gloss, and holes. The evaluation was made with x when a defective phenomenon such as opening was observed.

(Surface Resistivity) Using a Hiresta-UP (MCP-HT450, J box U type) manufactured by Mitsubishi Chemical Co., measured with an applied voltage of 500 V, a measuring time of 60 seconds, an environmental temperature of 23 ° C. and an environmental humidity of 55%. I went.

(Examples 1 to 4 and Comparative Examples 1 to 5) The polypropylene resin compositions (a) to (f) shown in Table 1 and a chemical foaming agent (CF, Clariant Co., Ltd.) were mixed by stirring at respective ratios. Toshiba Toshiba 90mm single screw extruder (non-vent, L
/ D = 34), cylinder temperature 220 ° C, 100M /
Foam extrusion was performed from an M circular die (set temperature 190 ° C.) to form each foam sheet sample having a sheet thickness of 0.80 mm. Table 1 shows the measurement results of the sheet density and the closed cell rate of the obtained foamed sheet.

[0043]

[Table 1]

[0044] High melt tension PP: MI = 3.0 g / min High melt tension PP: MI = 3.4 g / min Crystalline PP: MI = 4.0 g / min Foaming agent type: CF = chemical foaming agent, carbon dioxide = physical foaming agent MI: 230 ° C measured value (JIS-K6758 method)

Biaxially stretched films of polypropylene resin having a film thickness of 0.01 mm shown in (g) to (i) shown in Table 2 were laminated by dry lamination in the combinations shown in Table 3 to obtain a laminated foam sheet. . The drawdown property and thermoformability during secondary molding of the laminated foam sheet were measured, and the results are shown in Table 3.

[0046]

[Table 2]

Antistatic agent: Electrostripper TS-3B manufactured by Kao Corporation

[0048]

[Table 3]

The laminated foam sheets of the respective examples had a small drawdown amount at the time of secondary moldability, and the obtained containers had no defective appearance such as bridges.

[0050]

According to the present invention, by the usual continuous molding method,
It was possible to obtain a stable polypropylene-based resin laminated foam sheet having good antistatic properties without problems such as drawdown and partial peeling of the film layer and the foam layer, and obtained by thermoforming the sheet. The container can be used as a laminated foam container suitable for a package of electronic parts, which protects the contents from shocks such as vibrations or drops during transportation, and suppresses electrostatic trouble due to friction with the contents. it can.

[Brief description of drawings]

FIG. 1 is a drawing drawdown measuring apparatus used in the present invention.

[Explanation of symbols]

1 foam sheet 2 clamp plate 31 Infrared heater (top) 32 infrared heater (bottom) 4 Laser displacement measuring machine 5 laser

Continued front page    F term (reference) 3E033 BA16 BB08 BB10 CA03 FA04                       GA03                 3E086 AB01 AC33 BA04 BA15 BA16                       BB01 BB35 BB51 BB62 BB67                       BB84 BB90 CA31                 4F100 AK07A AK07B AK07C AL05A                       DJ02A EJ38B EJ38C GB16                       JA00B JA00C JA03B JA03C                       JA11A JA13A JG03 JG03B                       JG03C JG04B JG04C JK10                       YY00A YY00B YY00C

Claims (4)

[Claims] 1. A sheet density of more than 300 kgm ^-3 is 8
A polypropylene-based resin laminated foam sheet obtained by laminating a biaxially stretched antistatic polypropylene-based resin film on at least one side of a polypropylene-based resin foamed sheet having a closed cell ratio of 50 kgm ^-3 or less and 40% or more. , The antistatic polypropylene resin film,
The heat shrinkage in the film winding direction and width direction when left at 150 ° C. for 5 minutes is 1.5 to 4.0%, and the surface resistivity of the sheet surface on the film side is less than 10 ¹² Ω. Polypropylene resin laminated foam sheet. 2. The polypropylene-based resin laminated foam sheet according to claim 1, wherein the polypropylene-based resin foamed sheet contains a polypropylene-based resin (A) having a melt tension at 200 ° C. of 4.0 g or more as a main component. 3. The polypropylene-based resin foamed sheet contains 50 parts or more of a high melt-strength polypropylene-based resin (A) having a melt tension at 200 ° C. of 4.0 g or more, and a linear crystal as the remaining component. The polypropylene-based resin laminated foam sheet according to claim 1, which contains a hydrophilic polypropylene (B). 4. A laminated foam container obtained by thermoforming the polypropylene resin laminated foam sheet according to claim 1.