JP2013075425A - Laminate foamed sheet, container, and method of producing laminate foamed sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate foamed sheet by which a molding excellent in heat resistance can be produced, and which facilitates material recycling of remnants produced in producing the molding, this molding itself, etc.SOLUTION: The method for producing a laminate foamed sheet is a method for producing a laminate foamed sheet to obtain a laminate foamed sheet by laminating a resin film on a polystyrene resin foamed sheet which is obtained by extrude foaming a resin composition, wherein the resin composition has a polystyrene resin and a polyphenylene ether resin, and also contains the polyphenylene ether resin of 10-50 pts.mass for the total 100 pts.mass of the polystyrene resin and the polyphenylene ether resin, and a polystyrene resin film, which has a polystyrene resin and a polyphenylene ether resin and has a softening temperature higher than the resin composition, is used as the resin film.

Description

  The present invention relates to a laminated foam sheet, a container obtained by molding the laminated foam sheet, and a method for producing the laminated foam sheet.

  Conventionally, polystyrene-based resin foam sheets have been widely used as materials for food containers (food trays, cups, etc.). However, a food container formed of a polystyrene resin foam sheet made of a polystyrene resin is not sufficiently high in heat resistance, and thus has a problem of being deformed when heated by a microwave oven or the like. On the other hand, in order to improve heat resistance, a polystyrene resin foam sheet (also referred to as “foam sheet”) formed by foaming a resin composition containing a polystyrene resin and a polyphenylene ether resin with a foaming agent. It has been proposed (for example, Patent Document 1).

Japanese Patent No. 4699327

  However, since the foam sheet is mostly occupied by a thin cell membrane, the molded product (container, etc.) obtained by molding the foam sheet is easily deformed even if it receives a little heat. In some cases, heat can cause holes to open. Such a problem is difficult to solve even if the heat resistance of the resin composition used is improved as long as the surface of the molded product is formed of a thin cell membrane.

  In order to solve such problems, a film made of polypropylene resin having higher heat resistance than polystyrene resin is laminated on one side of the foam sheet to produce a laminated foam sheet, and the polypropylene film becomes the inside of the container. In this way, the laminated foam sheet is molded to produce a container.

  By the way, when producing a molded product from this laminated foam sheet, the laminated foam sheet is thermoformed to form the shape of the molded product on the laminated foam sheet, and a punching process for cutting along the outer edge of the molded product is performed. Although it is generally carried out, a lot of offcuts are generated at that time. In order to recycle the end material, it is conceivable that the end material is melted to produce the foam sheet. However, since polypropylene is incompatible with polystyrene, the end material can be melted even if the end material is melted. Is not sufficiently mixed with polystyrene, and foaming a resin composition that is not sufficiently mixed as described above causes the bubble film to not expand sufficiently and the bubbles are connected to each other, resulting in an increase in the open cell ratio. Problems can arise. In addition, the same problem can occur when material recycling is performed not only on the end material but also on the used molded product after use or the laminated foam sheet that remains without being used for forming the molded product.

  In view of the above problems, the present invention is capable of producing a molded product having excellent heat resistance, and is also a laminated foam that is easy to material recycle the end material generated when producing this molded product, the molded product itself, etc. It is an object to obtain a molded product of a sheet and the laminated foam sheet.

  In order to solve the above-mentioned problems, the present invention contains a polystyrene resin and a polyphenylene ether resin, and the polyphenylene ether resin is 10 parts per 100 parts by mass of the total amount of the polystyrene resin and the polyphenylene ether resin. It is a manufacturing method of the laminated foam sheet which laminates | stacks a resin film on the polystyrene-type resin foam sheet formed by extruding and foaming the resin composition contained by 50 mass parts, Comprising: As said resin film, Provided is a method for producing a laminated foamed sheet, wherein a polystyrene resin film containing a polystyrene resin and a polyphenylene ether resin and having a softening temperature higher than that of the resin composition is used.

  Such a method for producing a laminated foamed sheet is a laminated foamed sheet capable of producing a molded product having excellent heat resistance by using a polystyrene resin film having a softening temperature higher than that of the resin composition as the resin film. Can be obtained. Moreover, the manufacturing method of such a laminated foam sheet uses the end material generated when producing a molded article by using as the resin film a polystyrene resin film containing a polystyrene resin and a polyphenylene ether resin. It is possible to obtain a laminated foam sheet in which the molded product itself can be easily recycled.

  In order to solve the above problems, the present invention includes a polystyrene resin and a polyphenylene ether resin, and the polyphenylene ether resin with respect to 100 parts by mass of the total amount of the polystyrene resin and the polyphenylene ether resin. Is a laminated foam sheet comprising a polystyrene resin foam sheet formed by extrusion foaming a resin composition containing 10 to 50 parts by mass, and a resin film laminated on the polystyrene resin foam sheet, Provided is a laminated foamed sheet characterized in that the resin film includes a polystyrene resin and a polyphenylene ether resin and a polystyrene resin film having a softening temperature higher than that of the resin composition.

  Furthermore, the present invention is a container in which a laminated foam sheet is molded, wherein the laminated foam sheet is molded, and the container inside is formed of the polystyrene resin film. Provided as a solution.

  ADVANTAGE OF THE INVENTION According to this invention, the laminated foam sheet which can produce the molded article excellent in heat resistance, and is easy to material-recycle the end material generated when producing this molded article, this molded article itself, etc., and this lamination A molded article of a foam sheet can be provided.

The figure which shows the TG / DTA chart of a hydrotalcite. The figure which shows the powder X-ray-diffraction pattern of a hydrotalcite. The figure which shows the powder X-ray-diffraction pattern of a hydrotalcite baked material.

  Hereinafter, an embodiment of the present invention will be described.

First, the laminated foam sheet of this embodiment is demonstrated.
The laminated foam sheet of this embodiment includes a first surface layer on one surface side, a second surface layer on the other surface side, and an intermediate layer provided between these surface layers.
Specifically, the laminated foam sheet of the present embodiment includes a polystyrene resin foam sheet formed by extruding and foaming a resin composition containing a polystyrene resin and a polyphenylene ether resin as an intermediate layer. The surface layer includes a first polystyrene resin film laminated on one side of the polystyrene resin foam sheet, containing a polystyrene resin and a polyphenylene ether resin, and having a softening temperature higher than that of the resin composition, As the surface layer, a second polystyrene resin film is provided which is laminated on the other surface side of the polystyrene resin foam sheet and contains a polystyrene resin.
In addition, the softening temperature in this specification means Vicat softening temperature (JIS K7206-1991, Method B, 50 ° C./h).
The polystyrene resin foam sheet is in a foamed state by extrusion foaming as described above, whereas the polystyrene resin film in the present specification is formed in a non-foamed state in a film shape. Means.

  If the laminated foam sheet of this embodiment is a case where it is used for formation of the container for food packaging, for example, Preferably it is set as the thickness of 1.5-3.0 mm.

(Polystyrene resin foam sheet)
The polystyrene-based resin foam sheet preferably has a density of 0.055 to 0.18 g / cm ³ , for example, when the obtained laminated foam sheet is used for forming a food packaging container.

The open cell ratio of the polystyrene-based resin foam sheet is preferably 18% or less, more preferably 3 to 18%.
The polystyrene-based resin foam sheet can be gradually diffused to such an extent that the user does not feel the internal odor component by having the above-described characteristics relating to the open cell ratio, and is particularly excellent in the odor suppression effect. Have advantages.

The open cell ratio can be calculated from the following formula from the volume V of the foam sheet specimen measured using an air-comparing hydrometer (manufactured by Tokyo Science Co., Ltd.).
Open cell ratio (%) = (V ₀ −V) / V ₀ × 100
In the above formula, V is the volume of the test specimen (cm ³ ) measured by the above method, and V ₀ is the apparent volume (cm ³ ) of the test specimen calculated from the outer dimensions of the test specimen used for the measurement. It is.

The polystyrene-based resin foam sheet preferably has an average cell diameter of 80 to 450 μm.
In addition, the average cell diameter of a polystyrene-type resin foam sheet can be measured based on the method described in ASTM D2842-69. That is, the test foam sheet sample was cut along a plane orthogonal to the extrusion direction, and cut along a plane extending in the extrusion direction and the thickness direction, and both outer sides 1/10 in the thickness direction of each cut surface. The portion excluding this portion is photographed with a scanning electron microscope (“S-3000N” manufactured by Hitachi, Ltd.) 17 to 20 times, and if necessary, enlarged up to 200 times. Each of the four captured images is printed on A4 paper, and each of the MD direction (extrusion direction), the TD direction (direction perpendicular to the extrusion direction and along the sheet surface), and the VD direction (thickness direction) is followed. Draw 6 parallel lines (length 60mm) for each A4 paper. From the number of bubbles overlapping such a line segment, the average chord length (t) of the bubbles in each direction is calculated by the following equation (1). However, the line segment is drawn as much as possible so that the bubbles do not touch only at the contact points, and if they are touched, they are included in the number of bubbles.
Average chord length (t) = 60 / (number of bubbles × photo magnification) (1)
And the bubble diameter in each direction is computed by following formula (2).
D = t / 0.616 (2)
Further, based on each bubble diameter (D _MD , D _TD , D _VD ) measured as described above, the average bubble diameter is calculated by the following formula (3).
Average bubble diameter (mm) = (D _MD + D _TD + D _VD ) / 3 (3)
In addition, when the thickness of the test foam sheet sample is thin and a line segment of 60 mm length cannot be drawn in the VD direction, the number of bubbles overlapping the 30 mm or 20 mm length line segment is counted, and the length of 60 mm Convert to the number of bubbles in the line.

By setting the average cell diameter to 80 μm or more in the polystyrene resin foam sheet, the bubble film becomes thick and the open cell rate is likely to be lowered (the open cell rate tends to be 18% or less). And the effect that intensity | strength becomes high is exhibited by making an average bubble diameter 80 micrometers or more.
In addition, when the average cell diameter is 450 μm or less, the polystyrene-based resin foam sheet is not too large, the appearance is good, the smoothness and gloss are excellent, and it is difficult to break. There is an effect.

The polystyrene resin foam sheet preferably has a normal butyric acid content of less than 0.50 ppm, more preferably less than 0.30 ppm.
When the content of normal butyric acid in the polystyrene-based resin foam sheet is less than 0.50 ppm, the laminated foam sheet according to this embodiment has an advantage that odor is further suppressed.

  The polystyrene resin used for forming such a polystyrene resin foam sheet is preferably a polystyrene resin such as a styrene homopolymer from the viewpoint of compatibility with the polyphenylene ether resin.

  On the other hand, the polyphenylene ether-based resin is effective for imparting heat resistance, and a resin represented by the following chemical formula 1 can be generally employed.

Here, R ¹ and R ² represent an alkyl group having 1 to 4 carbon atoms or a halogen atom, and n is a positive integer representing the degree of polymerization.
For example, poly (2,6-dimethylphenylene-1,4-ether), poly (2,6-diethylphenylene-1,4-ether), poly (2,6-dichlorophenylene-1,4-ether) Ether) or the like may be used in this embodiment.
The degree of polymerization n is usually in the range of 10 to 5000.

This polyphenylene ether resin is contained in a proportion of 10 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass in total with the polystyrene resin.
The polyphenylene ether-based resin is effective for improving heat resistance, and it is contained in a ratio of 10 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass in total with the polystyrene resin. If it is less than the range, the addition effect of the polyphenylene ether resin may not be sufficiently exerted. Conversely, even if the polyphenylene ether resin is contained exceeding the above range, the addition effect of the polyphenylene ether resin is further exhibited. This is because there is a risk of not being done.
Moreover, since it is generally more expensive than a polystyrene resin, if the polyphenylene ether resin is contained beyond the above range, there is a possibility of causing a problem in terms of material cost.

  Usually, the Vicat softening temperature of polystyrene resin (JIS K7206-1991, Method B, 50 ° C./h) is about 102 ° C., but by including the polyphenylene ether resin as described above, the Vicat softening temperature is reduced. It can be improved to a range of 110 to 155 ° C., and by using the polyphenylene ether resin and the polystyrene resin, the heat resistance of the obtained laminated foam sheet or a product obtained by secondary processing of the laminated foam sheet is improved. Can be planned.

In general, when heat resistance is required for a product made of polystyrene resin, styrene-methacrylic acid copolymer, styrene-maleic anhydride copolymer, styrene-maleimide having a higher Vicat softening temperature than styrene homopolymer Copolymers, copolymers such as polyparamethylstyrene resin, and the like are employed as the forming material.
On the other hand, the method of blending the polyphenylene ether-based resin as described above is excellent not only in imparting heat resistance to the product but also in imparting excellent toughness.

  Therefore, by using a polyphenylene ether resin and a polystyrene resin to form a container such as a foam tray, it is possible to form a foam tray that does not crack even if sudden deformation is applied.

  The polystyrene-based resin foam sheet is obtained by melting and mixing a resin composition containing the polystyrene-based resin and the polyphenylene ether-based resin in a predetermined ratio in an extruder, and melt-mixing the resin composition in the extruder. It is formed by extrusion foaming.

  The resin composition preferably contains at least one of a calcined hydrotalcite and a zeolite as a deodorant in addition to the polystyrene resin and the polyphenylene ether resin.

Hydrotalcite is a kind of naturally occurring clay mineral and is usually a double hydroxide represented by the following general formula.

M ¹ _8-x M ² _x (OH) ₁₆ CO ₂ · nH ₂ O

Here, the ^{M 1, Mg 2+, Fe 2+} , Zn 2+, Ca 2+, Li 2+, Ni 2+, Co 2+, is any of Cu ^2+, as M ² is Any one of Al ³⁺ , Fe ³⁺ and Mn ³⁺ , x is preferably 2 to 5, and n is an integer of 0 or more.

  In recent years, synthetic products are also commercially available. For example, an aqueous suspension of basic magnesium carbonate particles and an aqueous suspension of aluminum hydroxide have a ratio of magnesium atom to aluminum atom (Mg / Al). The mixture is mixed so as to have a predetermined ratio (for example, 2.6 to 3.2), and caustic alkali such as sodium hydroxide, potassium hydroxide, ammonium hydroxide is further added to obtain a reaction solution having a pH of 8.5 to 11.5. The step of obtaining, the step of heating and aging the reaction solution obtained by the step at, for example, 50 to 100 ° C. for 0.5 to 20 hours, and hydrotalcite particles from the solution after heating and aging in the step Products manufactured through solid-liquid separation, washing, dehydration and drying processes are commercially available, and the calcined product obtained by firing such hydrotalcite is also natural hydrotalcite. It can be used as well as form calcined product.

  As can be seen from the TG / DTA chart shown in FIG. 1, hydrotalcite releases adsorbed water or crystal water when heated, and adsorbed water is released by firing at 200 ° C. or higher. When calcined at 400 ° C. or higher, for example, 550 ° C., carbonate radicals and hydroxyl groups are eliminated, and analyzed by powder X-ray diffractometer (manufactured by Rigaku Corporation, RAD system) at 2θ = 10 to 70 degrees, It is a substance which shows a chart result as shown in FIG.

The hydrotalcite fired product is a compound obtained by firing at a temperature as described above, and is a compound that retains anion exchange ability even after firing.
As the hydrotalcite fired product, for example, a material represented by the following general formula is preferably employed.

Mg _0.7 Al _0.3 O _1.15

The calcined hydrotalcite exhibits three peaks characteristic of a powder X-ray diffraction pattern analyzed at 2θ = 10 to 70 degrees with a powder X-ray diffractometer (manufactured by Rigaku Corporation, RAD system). FIG. 3 is a substance showing a chart result as shown in FIG.

The content of the fired hydrotalcite in the resin composition is advantageous in that the larger the laminated foam sheet according to the present embodiment, the odor can be further suppressed. If the amount is excessively large, the foamability of the resin composition may be reduced.
Therefore, preferable content of the calcined hydrotalcite with respect to 100 parts by mass of the total amount of the polystyrene resin and the polyphenylene ether resin in that a good foaming state can be imparted to the polystyrene resin foam sheet while suppressing odor. Is 0.05 to 20 parts by mass, and a more preferable content is 0.1 to 10 parts by mass.
The smaller the particle size of the fired hydrotalcite, the easier it is to disperse in the resin composition and the odor control effect becomes higher, but those with an excessively small particle size are commercially available. In addition to being difficult to obtain, it is likely to float up and be difficult to handle.
Therefore, it is preferable that the particle diameter (volume average diameter) of the fired product employed in the present embodiment is 1 to 100 μm in that the polystyrene-based resin foam sheet with suppressed odor can be easily manufactured.

As the zeolite, both a hydrophobic zeolite and a hydrophilic zeolite can be used. However, the hydrophobic zeolite can adsorb the organic substance component which is a causative component of the odor. Since it is possible to suppress the odor, it is preferable to use a hydrophobic zeolite from the viewpoint that the odor can be further suppressed.
Hydrophobic zeolite means zeolite with a small Al component, and can be confirmed by fluorescent X-ray analysis.
More specifically, the hydrophobic zeolite means a zeolite having a molar ratio (SiO ₂ / Al ₂ O ₃ ) of 1.5 or more when converted into silica and alumina, and in particular, the molar ratio is 10 What becomes the above is preferable.

  Furthermore, you may make the said resin composition contain the component for foaming, such as a foaming agent and a bubble regulator, and the various additives currently utilized as a raw material of a general polystyrene-type resin foam sheet.

As said foaming agent, a volatile foaming agent, an inorganic gas type foaming agent, a decomposable foaming agent, etc. are used individually or in combination of 2 or more, respectively. Examples of the volatile blowing agent include aliphatic hydrocarbons such as propane, normal butane, isobutane, pentane and hexane, and cyclic aliphatic hydrocarbons such as cyclobutane and cyclopentane. As the inorganic gas-based foaming agent, an inert gas such as carbon dioxide, nitrogen or air is used. Examples of the decomposable foaming agent include azodicarbonamide, dinitrosopentamethylenetetramine, azobisisobutyronitrile, sodium bicarbonate, and the like. However, from the viewpoint of improving the secondary foamability of the polystyrene resin foam sheet during heating prior to thermoforming of the laminated foam sheet, it is desirable to use a volatile foaming agent as the main foaming agent. The amount of foaming agent added depends on the type of foaming agent, the base resin, the target foaming ratio, etc., so select the desired foaming ratio according to the type of foaming agent and base resin. do it.
Examples of the air conditioner used in combination with the foaming agent include inorganic powders such as talc and silica, acidic salts of polyvalent carboxylic acids, and reaction mixtures of polyvalent carboxylic acids with sodium carbonate or sodium bicarbonate. It is preferable that the addition amount of a bubble regulator is 0.5-5 mass parts with respect to a total of 100 mass parts of the said polystyrene-type resin and the said polyphenylene ether resin.
Examples of the additive include a stabilizer, an ultraviolet absorber, an antioxidant, and a colorant.

(First polystyrene resin film)
The first polystyrene-based resin film preferably has a thickness of 15 to 50 μm, for example, when the obtained laminated foam sheet is used for forming a food packaging container.

The first polystyrene resin film preferably has a normal butyric acid content of less than 0.50 ppm, more preferably less than 0.30 ppm.
When the content of normal butyric acid in the first polystyrene resin film is less than 0.50 ppm, the laminated foam sheet according to this embodiment has an advantage that odor is further suppressed.

  The polystyrene resin used for the formation of such a first polystyrene resin film is preferably a polystyrene resin such as a styrene homopolymer from the viewpoint of compatibility with the polyphenylene ether resin.

  On the other hand, the polyphenylene ether-based resin is effective for imparting heat resistance, and the one represented by the above chemical formula 1 can be generally employed.

This polyphenylene ether resin is preferably contained in a proportion of 10 parts by mass or more and 70 parts by mass or less with respect to 100 parts by mass in total with the polystyrene resin.
The first polystyrene resin film has an advantage that the heat resistance is increased by containing 10 parts by mass or more of polyphenylene ether resin with respect to a total of 100 parts by mass of the polyphenylene ether resin and the polystyrene resin. There is. Moreover, since it is generally more expensive than a polystyrene resin, the first polystyrene resin film is a polyphenylene ether resin relative to a total of 100 parts by mass of the polyphenylene ether resin and the polystyrene resin. Is contained in an amount of 70 parts by mass or less, there is an advantage that the material cost can be suppressed.

  The first polystyrene resin film preferably contains at least one of a calcined hydrotalcite and zeolite as a deodorant in addition to the polystyrene resin and the polyphenylene ether resin.

As the hydrotalcite fired product used for the first polystyrene-based resin film, for example, a material represented by the following general formula is preferably employed.

Mg _0.7 Al _0.3 O _1.15

When the first polystyrene resin film contains the hydrotalcite fired product, the hydrotalcite fired product is preferably used with respect to 100 parts by mass of the total amount of the polystyrene resin and the polyphenylene ether resin. 0.05-20 mass parts, More preferably, it contains 0.1-10 mass parts.
Moreover, the smaller the particle size of the hydrotalcite fired product is, the easier it is to be dispersed in the first polystyrene resin film and the higher the odor suppressing effect, but the smaller the particle size is commercially available, etc. It is not easy to obtain because it has not been removed, and it is likely that it will rise easily and be difficult to handle.
Therefore, it is preferable that the particle diameter (volume average diameter) of the fired product employed in the present embodiment is 1 to 100 μm in that the first polystyrene resin film with suppressed odor can be easily manufactured.

  As the zeolite used for the first polystyrene-based resin film, both hydrophobic zeolite and hydrophilic zeolite can be used. However, hydrophobic zeolite can adsorb components of organic substances that cause odor. It is possible to suppress the odor, and it is preferable to use a hydrophobic zeolite from the viewpoint of further suppressing the odor.

  Furthermore, the first polystyrene resin film may contain a stabilizer, an ultraviolet absorber, an antioxidant, a colorant, and the like as the additive.

(Second polystyrene resin film)
The second polystyrene resin film is a polystyrene resin film that is the same as or different from the first polystyrene resin film. When the second polystyrene resin film is a polystyrene resin film different from the first polystyrene resin film, the second polystyrene resin film may not include a polyphenylene ether resin.

  The laminated foam sheet of this embodiment is configured as described above. Next, a method for producing the laminated foam sheet of this embodiment will be described.

In the method for producing a laminated foam sheet of this embodiment, a first polystyrene resin film is laminated on one side of a polystyrene resin foam sheet, and a second polystyrene resin film is laminated on the other side of the polystyrene resin foam sheet. Thus, a laminated foam sheet is produced.
The lamination method for laminating the polystyrene resin film on the polystyrene resin foam sheet is not particularly limited. For example, (1) a method in which a polystyrene resin foam sheet and a polystyrene resin film are laminated and integrated with each other by a coextrusion method. (2) A method of extrusion laminating a polystyrene resin film on a polystyrene resin foam sheet, (3) a method of thermally laminating a polystyrene resin film on a polystyrene resin foam sheet, and the like.

  In addition, as a manufacturing method of the said polystyrene-type resin foam sheet, a polystyrene-type resin, a polyphenylene-type resin, the said deodorizing agent, and the said foaming agent are supplied to an extruder, and are melt-kneaded, and a foamable polystyrene-type resin composition And a method of producing a polystyrene-based resin foam sheet by extruding and foaming this expandable polystyrene-based resin composition from a die attached to the tip of an extruder. The die is not particularly limited as long as it is widely used in extrusion foaming, and examples thereof include a T die and an annular die.

  And when T-die is used as die | dye, a polystyrene-type resin foam sheet can be manufactured by carrying out extrusion foaming to a sheet form from an extruder. On the other hand, when an annular die is used as the die, a cylindrical body is produced by extrusion foaming from the annular die into a cylindrical shape, and the cylindrical body is gradually expanded in diameter and then supplied to a cooling mandrel for cooling. Then, a polystyrene-type resin foam sheet can be manufactured by cut | disconnecting a cylindrical body continuously between the inner and outer peripheral surfaces in the extrusion direction, and opening and developing.

Next, the method (1) will be specifically described. First, as an apparatus for laminating, two extruders, a first extruder and a second extruder, and a coextrusion die composed of a confluence die and an annular die connected to the confluence die are prepared. Both the machine and the second extruder are connected to the confluence die of the coextrusion die.
The polystyrene resin, the polyphenylene resin, the deodorant, and the foaming agent are supplied to the first extruder and melt kneaded to obtain a foamable polystyrene resin composition. The resin and the deodorant are supplied to the second extruder, melted and kneaded in the absence of the foaming agent, and the molten resin extruded from both extruders is merged by the co-extrusion die. A foamable laminate comprising a foamable polystyrene resin composition layer having a circular cross section and a non-foamable polystyrene resin composition layer laminated on the outer peripheral surface of the foamable polystyrene resin composition layer. The foamable laminate is supplied to an annular die and extruded and foamed from the annular die into a cylindrical shape to obtain a cylindrical foam.

Next, after gradually expanding the diameter of the cylindrical foam and supplying the cooling mandrel to cool the cylindrical foam, the cylindrical foam is continuously inserted between the inner and outer peripheral surfaces in the extrusion direction. By cutting it over, it can be opened and formed into a sheet shape, and a polystyrene resin foam sheet and a polystyrene resin film can be laminated and integrated.
The ratio between the outer diameter of the inner die at the opening of the annular die and the outer diameter of the cooling mandrel on the extruder side (outer diameter of the inner die / outer diameter of the cooling mandrel on the extruder side), so-called The blow-up ratio is preferably 2.5 to 3.5.

  The laminated foam sheet of this embodiment and the method for producing the laminated foam sheet are configured as described above. Next, the container of this embodiment will be described.

The container of the present embodiment can be produced, for example, by subjecting a laminated foamed sheet obtained by the above manufacturing method to molding such as thermoforming or bending. In that case, this shaping | molding is implemented so that a 1st polystyrene-type resin film may become an inner side of a container.
The container of the present embodiment is formed so that a first polystyrene resin film containing a polystyrene resin and a polyphenylene ether resin and having a softening point higher than that of the resin composition of the polystyrene resin foam sheet is inside the container. By being made, it becomes a container excellent in heat resistance. In addition, since the container of this embodiment uses a polystyrene-based resin film as the resin film, there is an advantage that the scraps generated when the container is produced, the container itself, and the like are easily recycled.

Examples of the thermoforming method include vacuum forming, pressure forming, vacuum pressure forming, press forming, and the like.
Moreover, as said bending molding, the method of giving a V-groove process to a laminated foam sheet, and bend | folding through this V-groove, and making it a folding box container etc. is mentioned.

In addition, although the laminated foam sheet of this embodiment, the manufacturing method of a laminated foam sheet, and a container have the said advantage by the said structure, the laminated foam sheet of this invention, the manufacturing method of a laminated foam sheet, and A container is not limited to the said structure, A design change is possible suitably.
For example, the laminated foam sheet of this embodiment includes a second polystyrene resin film, but the laminated foam sheet of the present invention is laminated on one side of the polystyrene resin foam sheet and the polystyrene resin foam sheet. As long as the first polystyrene resin film is provided, the resin film may not be laminated on the other surface side of the polystyrene resin foam sheet.
Moreover, the laminated foam sheet of this invention may be equipped with another layer between a 1st surface layer and an intermediate | middle layer, and may be equipped with another layer between a 2nd surface layer and an intermediate | middle layer. .

Claims (5)

A resin composition comprising a polystyrene resin and a polyphenylene ether resin and 10 to 50 parts by mass of the polyphenylene ether resin with respect to 100 parts by mass of the total amount of the polystyrene resin and the polyphenylene ether resin. A method for producing a laminated foamed sheet obtained by laminating a resin film on a polystyrene resin foamed sheet obtained by extrusion foaming to obtain a laminated foamed sheet,
A method for producing a laminated foamed sheet, comprising using a polystyrene resin film containing a polystyrene resin and a polyphenylene ether resin and having a softening temperature higher than that of the resin composition as the resin film.   The polystyrene resin film in which 10 to 70 parts by mass of the polyphenylene ether resin is contained with respect to 100 parts by mass of the total amount of the polystyrene resin and the polyphenylene ether resin as the polystyrene resin film. The manufacturing method of the laminated foam sheet of description.   The method for producing a laminated foam sheet according to claim 1 or 2, wherein a polystyrene resin film further containing at least one of zeolite and a calcined hydrotalcite is used as the polystyrene resin film. A resin composition comprising a polystyrene resin and a polyphenylene ether resin and 10 to 50 parts by mass of the polyphenylene ether resin with respect to 100 parts by mass of the total amount of the polystyrene resin and the polyphenylene ether resin. A laminated foam sheet comprising a polystyrene resin foam sheet formed by extrusion foaming, and a resin film laminated on the polystyrene resin foam sheet,
The laminated foam sheet, wherein the resin film includes a polystyrene resin and a polyphenylene ether resin and a polystyrene resin film having a softening temperature higher than that of the resin composition. A container in which a laminated foam sheet is formed,
5. A container, wherein the laminated foam sheet according to claim 4 is molded, and the inside of the container is formed of the polystyrene resin film.

Images