JP2001151220A - Fruit and vegetable tray - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel fruit and vegetable tray which can support a variety of objects to be packaged by providing a balance in wide physical properties with controlled strength and flexibility of a foamed resin composition. SOLUTION: The fruit and vegetable tray A is molded into a form having a plurality of storage recesses 1 from a foamed sheet of a mixed resin comprising a polystyrene based resin, an ethylene-styrene copolymer and a polyethylene based resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fruit and vegetable tray having a plurality of storage recesses.

[0002]

2. Description of the Related Art Conventionally, in the storage and packaging of fruits and vegetables such as peaches and pears, a large number of foamed sheets obtained mainly by forming a foamed sheet such as a polystyrene resin foam sheet, a crosslinked polyethylene resin foam sheet, a polypropylene resin foam sheet, etc., are used. Or a pulp mold tray. Each of these trays has advantages and disadvantages depending on the type of fruits and vegetables to be stored and the form of storage, and thus these trays are properly used.

For example, a tray made of a polystyrene resin foam sheet is often used for storing pears having a certain weight and a hard surface, and a tray made of a crosslinked polyethylene resin foam sheet is made of a peach with a soft surface which is easily scratched. Used for storage. Pulp molds are also used to store apples and tomatoes. Thus, a wide variety of fruit and vegetable trays are required. However, fruit and vegetable trays generally need to be stocked some time ahead of the harvest season, in anticipation of that year's production.

[0004] Therefore, in order to use the various trays as described above, it is necessary to always secure a large amount of inventory for all trays, and it is necessary to secure a storage place and inventory management. A problem arises in that labor and cost are increased. There are also issues with each material.
For example, a tray made of a polystyrene-based resin foam sheet has a problem that it has low impact resistance due to the physical properties of the resin itself, and is liable to crack upon impact.

On the other hand, in the case of a tray made of a foamed sheet of polypropylene resin, it is not easy to obtain the foamed sheet itself, and the foamed sheet is limited to a specific polypropylene resin, and the resin itself is expensive. Is disadvantageous in terms of cost. The tray made of cross-linked polyethylene foam has a beautiful appearance due to its improved viscoelastic properties, and has excellent moldability and cushioning properties.
Since it has a crosslinked structure, it is difficult to recycle, and compared with other non-crosslinked foams, the production process is complicated, the equipment is expensive, and the cost is high.

[0006] Further, pulp molds are water-absorbing and thus have high strength when dried, but have the problem that they are weak and brittle due to the inclusion of moisture. For this reason, attempts have been made to unify the materials of the fruit and vegetable trays and to solve the problems of each material. For example, JP-A-8-230963 describes a tray for fruits and vegetables formed by laminating and molding a foamed polypropylene resin sheet having a relatively low density and a foamed polystyrene resin sheet.

The fruit and vegetable tray aims at coexistence of the flexibility of the polypropylene resin and the strength of the polystyrene resin. However, an adhesive is required to laminate both resins, and the cost is low. Neither in terms of recycling nor in terms of recycling, it was a complete solution.

[0008]

Therefore, in order to improve the impact resistance of a tray made of a polystyrene resin foam sheet and to impart flexibility, for example, rubber-modified polystyrene may be used instead of ordinary polystyrene. (JP-A-8-231748) or a styrene-butadiene-styrene block copolymer (so-called SBS type thermoplastic elastomer) mixed with a polystyrene resin and foamed (Japanese Patent Publication No. 4-49861). No.)
It has been proposed to.

The point of these technologies is that polystyrene
By adding rubber-based components such as butadiene-based polymer rubber and styrene-butadiene block copolymer with better impact resistance and flexibility than the polystyrene, these properties, which are the weak points of polystyrene, are improved. is there. However, according to studies by the inventors, the former has a limit in imparting flexibility, and the latter has a decrease in the closed cell rate of the foamed sheet and an increase in the dissipation of the foaming agent as the added amount of the rubber component increases. For this reason, it has been found that it is difficult to maintain the secondary moldability of the resin when the foam sheet is formed into a tray for fruits and vegetables by sheet molding.

[0010] Therefore, in the above-mentioned technique, the amount of the rubber-based component must be reduced in order to increase the secondary moldability of the resin and obtain a tray for fruits and vegetables having the same expansion ratio as that of the polystyrene-based resin. Although limited, the impact resistance is improved to some extent, but it may be difficult to achieve high flexibility, which can replace other flexible materials suitable for peach storage and packaging, for example. found.
Although various studies have been made to solve the above problems, at present, satisfactory products have not been obtained in the market.

It is an object of the present invention to provide a novel fruit and vegetable tray which can handle a variety of packages.

[0012]

Means for Solving the Problems In order to solve the above problems, the present inventors provide a wide balance of physical properties by controlling the strength and flexibility of a resin composition which is a raw material of a foamed sheet. As a result of conducting various studies to make it possible to respond to a variety of packages, a polyethylene resin as a flexible component and an ethylene-styrene copolymer to make both resins compatible with polystyrene resin Was found to be added, and the present invention was completed.

That is, the fruit and vegetable tray of the present invention has a plurality of storage recesses and is formed from a foamed sheet of a mixed resin of a polystyrene resin, an ethylene-styrene copolymer and a polyethylene resin. It is characterized by having.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below. In the present invention, as the polystyrene-based resin that is a part of the above constitution, in addition to a styrene homopolymer, a copolymer of styrene and other monomers, or a rubber-modified polystyrene can also be used. . Other monomers to be copolymerized with styrene include, for example, α-methylstyrene, methacrylic acid, acrylate, methacrylate,
Acrylonitrile, butadiene, maleic anhydride and the like can be mentioned.

The rubber-modified polystyrene has a structure in which rubber is dispersed in a polystyrene matrix in the form of particles, and polystyrene is further dispersed in the particles. The rubber particles have various forms such as salami or core-shell. I have. These polystyrene resins may be used alone or in combination of two or more. As the polyethylene-based resin, in addition to ethylene homopolymer, ethylene and α
-Copolymers with olefins and copolymers of ethylene with non-olefin monomers containing atoms such as carbon, oxygen and hydrogen in the functional groups.

Among them, low-density polyethylene (LDPE), high-density polyethylene (HDPE) and the like are listed as homopolymers of ethylene, and linear low-density polyethylene (L) is used as a copolymer of ethylene and α-olefin. −
LDPE), linear ultra low density polyethylene (VLDP)
E) and the like. Examples of the α-olefin include 1-butene, 1-hexene, 1-octene, 4-methyl 1-pentene and the like. Ethylene and carbon as a functional group,
Examples of the copolymer with a non-olefin monomer containing an atom such as oxygen and hydrogen include ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer resin, ethylene-ethyl acrylate copolymer resin, ethylene-methyl acrylate Copolymers, ethylene ionomer resins and the like can be mentioned.

In particular, the compatibility with polystyrene,
From the viewpoints of imparting flexibility and imparting flexibility, linear ultra-low density polyethylene is preferred. These polyethylene resins may be used alone or in combination of two or more. As the ethylene-styrene copolymer, various copolymers containing ethylene and styrene as structural units can be used alone or in combination of two or more. The composition of
50/50 to 20/80 by weight ratio of ethylene and styrene
Is preferably within the range.

Within this range, it can be said that an ethylene-styrene copolymer mixed with a polystyrene-based resin and a polyethylene-based resin is preferable in terms of resin composition.
That is, when the proportion of ethylene is higher than the above range, it may be difficult to obtain a low-density foam as a mixed resin mixed with a polystyrene-based resin and a polyethylene-based resin. When the proportion of ethylene is small, the effect of imparting flexibility to the tray may be weakened. A more preferred range of the weight ratio of ethylene to styrene is 45/55 to 25/75.

The ethylene-styrene copolymer is, for example, a compound represented by the general formula (1) belonging to an essentially random interpolymer disclosed in JP-A-3-16388.

[0020]

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Wherein a, b and c each represent an integer of 1 or more. ] Are preferred. The essentially random interpolymer here means that each monomer is arranged with some regularity so that a large block consisting of only one of the monomers does not occur in its main chain. Refers to a copolymer. More specifically, as shown in the general formula (1), two or more methylene groups are used so that none of the phenyl groups derived from the styrene monomer are substituted with carbon atoms adjacent to each other on the main chain. Separated copolymers are defined as essentially random interpolymers.

An essentially random interpolymer is
One or more α-olefin monomers, and one or more vinyl or vinylidene aromatic monomers, and / or
Alternatively, it contains polymerized units derived from one or more sterically hindered aliphatic or cycloaliphatic vinyl or vinylidene monomers, and optionally other polymerizable ethylenically unsaturated monomers. As used herein, the term "interpolymer" refers to a polymer made by polymerizing at least two different monomers.

As used herein, “essentially random” (one or more α-olefin monomers and
One or more vinyl or vinylidene aromatic monomers,
And / or in essentially random interpolymers containing polymer units derived from one or more sterically hindered aliphatic or cycloaliphatic vinyl or vinylidene monomers) The distribution can be represented by a Bernoulli statistical model. Or JC Randall in POLYMERSEQUEN
CE DETERMINATION, Carbon-13 NMR Method, Academic P
ress New York, 1977, pp. 71-78. means that it can be represented by a first-order or second-order Markov statistical model.

Preferably, the essentially random interpolymer comprises vinyl or vinylidene aromatic monomers in a block of three or more aromatic monomers in a total amount of one to one.
Contains no more than 5%. More preferably, the interpolymers of the present invention do not feature either a high degree of isotacticity or syndiotacticity. This is due to the C of the essentially random interpolymer of the present invention.
^{13 In the} NMR spectrum, the peak area corresponding to the main chain methylene and methine carbon representing either the meso dyad sequence or the racemic dyad sequence does not exceed 75% of the total peak area of the main chain methylene and methine carbon. Means

Suitable α-olefins include, for example, α-olefins having from 2 to about 20, preferably from 2 to about 12, and more preferably from 2 to about 8 carbons. Particularly preferred are ethylene, propylene, butene-1,4-methyl-1-pentene, hexene-1 or octene-1, or ethylene and one or more other propylene, butene-1,4-methyl-1-pentene, hexene-1 -1 or octene-1
It is a combination with These α-olefins do not contain an aromatic moiety.

Other optionally polymerizable ethylenically unsaturated monomers include norbornene and norbornene substituted with C _1-10 alkyl or C _6-10 aryl, such as interpolymer ethylene / styrene / norbornene. I can give it. Examples of the vinyl or vinylidene aromatic monomer suitably used for producing the interpolymer of the present invention include those represented by the following general formula (2).

[0027]

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Wherein R ¹ is selected from the group consisting of hydrogen and alkyl radicals containing from 1 to about 4 carbon atoms, preferably hydrogen or methyl. R ²
Are each independently selected from the group consisting of hydrogen and alkyl radicals containing from 1 to about 4 carbon atoms, preferably hydrogen or methyl. Ar is a phenyl group or a phenyl group substituted by a substituent having 1 to 5 carbon atoms selected from the group consisting of halo, C _1-4 alkyl and C _1-4 haloalkyl. n
Is from 0 to about 4, preferably from 0 to 2, most preferably 0
It is.

Examples of the vinyl aromatic monomer include styrene, vinyl toluene, α-methylstyrene, t-butylstyrene, chlorostyrene and all isomers thereof. Particularly preferred monomers include styrene and its alkyl or halogen substituted derivatives. Preferred monomers are lower alkyl (C ₁ -C ₄ ) or phenyl ring substitutes of styrene, such as styrene, α-methylstyrene, for example ortho-, meta-, or para-methylstyrene, halogenated styrene, paravinyltoluene or And mixtures thereof. A more preferred aromatic monovinyl monomer is styrene.

The term "sterically hindered aliphatic or cycloaliphatic vinyl or vinylidene compound" refers to an addition-polymerizable vinyl or vinylidene monomer represented by the following general formula (3).

[0031]

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Here, A ¹ is a sterically bulky aliphatic or cycloaliphatic substituent having up to 20 carbon atoms. R ¹
Is selected from the group consisting of hydrogen and alkyl radicals containing from 1 to about 4 carbon atoms, preferably hydrogen or methyl. R ² is each independently selected from the group consisting of hydrogen and an alkyl radical containing from 1 to about 4 carbon atoms, and is preferably hydrogen or methyl. Or alternatively, R ¹ and A ¹ form a ring system.

Preferred sterically hindered aliphatic or cycloaliphatic vinyl or vinylidene compounds are monomers in which any one carbon atom at the ethylenically unsaturated site is tertiary or quaternary substituted. Examples of such substituents include cycloaliphatic such as cyclohexyl, cyclohexenyl, cyclooctenyl, or their cyclic alkyl or aryl substituents, tertiary butyl and norbornyl, and the like. The most preferred aliphatic or cycloaliphatic vinyl or vinylidene compounds are the various isomers of cyclohexene and vinyl-ring substituted derivatives of substituted cyclohexenes, and 5-ethylenediene-2-norbornene. Particularly preferred are 1-, 3-, and 4-
It is vinylcyclohexane.

The ethylene-styrene copolymer alone cannot provide a foamed sheet having a density suitable for a fruit and vegetable tray. Incidentally, foams of a synthetic resin composed of ethylene and styrene can be found in, for example, Japanese Patent Publication No. 60-1338 and Japanese Patent Publication No. 4-11582. In both cases, foams with a high closed cell rate can be obtained, and foams with excellent flexibility and cushioning properties can be obtained.However, the former has a problem of cracking upon impact as described in the latter specification. Has been
It has been suggested that mixing of polystyrene and polyethylene, which are originally incompatible, causes a decrease in physical properties. It is easily assumed that when this is applied to a fruit and vegetable tray, it will lead to cracking during transportation.

The latter is one which has overcome the impact resistance, and in order to improve the compatibility between polystyrene and polyethylene, a hydrogenated styrene-butadiene copolymer is added as a compatibilizer. It is characterized by. However, this hydrogenated styrene-butadiene block copolymer is very expensive and causes an increase in cost. Further, as described above, in order to maintain the secondary moldability, the amount of the styrene-butadiene block copolymer to be added is limited, and the addition of a polyethylene resin having high gas permeability reduces the retention of the foaming agent. Therefore, the amount of addition is also limited.

Therefore, in any case, it is not possible to obtain a foamed sheet product suitable as a fruit and vegetable tray having a wide balance of physical properties by controlling strength and flexibility as in the present invention. On the other hand, in the case of the present invention, the ethylene-styrene copolymer, as well as the hydrogenated styrene-butadiene copolymer described above, not only acts as a compatibilizer between the polystyrene resin and the polyethylene resin, Even if the blending amount is increased, the retention of the foaming agent does not decrease, so that the effect of modifying polystyrene resin more than before is exhibited.

The mixing ratio of the above three resins, that is, polystyrene resin, ethylene-styrene copolymer, and polyethylene resin in the foamed sheet was 96 to 44% by weight of polystyrene resin and ethylene-styrene copolymer 2 -50% by weight, and polyethylene resin 2-3
It is preferably in the range of 0% by weight. Within this range, it can be said that the foamed sheet material to be formed into a tray for fruits and vegetables is suitable in terms of the correlation between strength and flexibility.

That is, the ratio of the polystyrene resin is 96
When the amount is more than 40% by weight, the impact resistance is reduced, and when the tray is impacted, the tray is liable to be broken. On the other hand, when the amount is less than 44% by weight, the strength is reduced, and a heavy and hard object such as a pear is held. It becomes difficult. The proportion of the polystyrene resin is preferably 90 to 50% by weight, particularly preferably 90 to 60% by weight. On the other hand, if the proportion of the polyethylene resin is more than 30% by weight, it is difficult to hold the foaming agent for a long period of time, which affects the secondary moldability.
If the amount is less than the weight percentage, the flexibility is reduced, and the surface of the peach or the like is particularly soft and is not suitable for storing the easily damaged items. The ratio of the polyethylene resin is preferably 2
-20% by weight, particularly preferably 2-15% by weight.

Further, if the proportion of the ethylene-styrene copolymer is more than 50% by weight, it may be difficult to obtain a low-density foam. Conversely, if it is less than 2% by weight, it may be difficult to obtain a compatibilizer. Because the effect is not obtained enough,
There is a possibility that a foam having a low open cell ratio, a uniform cell structure and a beautiful surface may not be obtained. The foam sheet used as the base of the fruit and vegetable tray of the present invention is produced by extrusion foaming into a sheet while adding a foaming agent for foaming the mixed resin to a mixed resin of the above three resins.

As the foaming agent, any of various known foaming agents such as gaseous, volatile and decomposable types can be used. For example, propane, n-butane, i-butane, n-pentane, Volatile hydrocarbons such as i-pentane are preferred, each of which is used alone,
Two or more can be used in combination. In addition, in addition to the foaming agent, in the foamed sheet, talc or the like as a bubble regulator for adjusting the size of bubbles during foaming, or a coloring agent such as a pigment, a stabilizer, a filler, an antistatic agent, Various additives such as a lubricant, a spreading agent, and a dispersant may be added within a range that does not impair the effects of the present invention.

The density of the foamed sheet thus obtained is:
It is preferably in the range of 0.020 to 0.30 g / cm ³ . Within this density range, it can be said that it is advantageous in maintaining the strength for retaining the shape of the fruit and vegetable tray and the flexibility necessary for the flexible contact with the objects to be stored such as pears and peaches. That is, if the density is less than 0.020 g / cm ³ , the strength is too weak to hold the object, and if it exceeds 0.30 g / cm ³ , the flexibility is inferior. There is a risk of injury. The density of the foamed sheet is particularly preferably 0.025 to 0.15 g / cm.
A range of ³ is preferred.

The tray for fruits and vegetables of the present invention is manufactured by forming the foamed sheet by various conventionally known thermoforming methods such as vacuum forming and pressure forming. One example of the fruit and vegetable tray of the present invention thus obtained is shown in FIGS. The tray A for fruits and vegetables shown in the figure is formed by forming a required number of recesses 1 for storage suitable for the shape of the object to be stored such as pears and peaches by sheet molding from a foamed sheet. It is also possible to form the inside of the concave portion 1 by forming ribs, protrusions, and the like, as is known.

[0043]

The present invention will be described below based on examples and comparative examples. Examples 1 to 8 and Comparative Examples 1 to 3 A total of 100 parts by weight of each of the resins shown in Table 1 was mixed with 0.5 part of talc as a cell regulator and mixed with a first extruder (caliber). tandem extruder consisting of a second extruder (φ65 mm) and a second extruder (φ65 mm)
The mixture was supplied to a hopper of an extruder, and was heated and melted in a barrel of a first extruder. Then, mixed butane was injected as a foaming agent and melted and mixed.

Then, the mixture was transferred to a second extruder and uniformly cooled in a barrel, and then discharged from a cylindrical die having a diameter of 60 mm at a discharge speed of 2 mm.
The foam was extruded into a cylindrical shape at 0 kg / hr, and the obtained cylindrical foam was cooled and formed with a cooling mandrel, cut at one point on the circumference with a cutter, and foamed with the thickness and density shown in Table 1. I got a sheet. In Examples 1-4 and Comparative Examples 1-3, a mixture ratio (weight ratio) of n-butane and isobutane of 70/30 was used as each of the mixed butanes. A mixture having a mixing ratio (weight ratio) of 30/70 was used.

The resins used are as follows. A: HRM-2 (manufactured by Denki Kagaku Co., polystyrene resin) B: HIE-7 (manufactured by Denki Kagaku Co., rubber modified polystyrene resin) C: LF240 (manufactured by Nippon Polychem Co., Ltd., low density polyethylene resin, density 0.924 g / cm) ³ ) D: VL100 (manufactured by Sumitomo Chemical Co., Ltd., linear ultra low density polyethylene resin, density 0.90 g / cm ³ ) E: EG8100 (manufactured by Dow Chemical Company, linear ultra low density polyethylene resin (ethylene-octene) polymer), density ^{0.870g / cm 3) F: LV540} ( manufactured by Japan Polychem Corporation, ethylene - vinyl acetate copolymer resin, VA content 20 wt%) G: DS201 (Dow Chemical Co., ethylene - styrene copolymer (styrene content However, a foamed sheet having a desired density could not be obtained with only 100% of the resin G of Comparative Example 2.

The obtained foamed sheet was molded together with a commercially available PP foamed sheet for comparison (Comparative Example 4) and a commercially available PE sheet (Comparative Example 5) into trays for transporting pears and peaches, respectively, and subjected to a transport test. Carried out. The pear tray had a shape capable of storing 22 pieces, and the peach tray had a shape capable of storing 13 pieces. For transporting pears, trays containing pears are stacked in two-tiered boxes in cardboard boxes and transported for peaches.
The tray containing the peaches was stored in a single step in a cardboard box. And put each cardboard box on the truck for about 400
After transporting km, the cardboard box was opened, and the condition of the tray inside and the surface condition of the fruit were confirmed.

Table 1 shows the results.

[0048]

[Table 1]

In the table, the open cell ratio is a value measured by an air pycnometer (air-comparison specific gravity meter). Table 2 below shows the appearance of the foam sheet and the evaluation of the secondary moldability.
It is as follows.

[0050]

[Table 2]

The results of the transport test are shown in Table 3 below.

[0052]

[Table 3]

FIG. 3 shows the amount of residual foaming agent in the foamed sheets of Examples 1 to 3 and Comparative Examples 1 and 3. As a method of measurement, after 1 hour, 5 days, 10 days, 20 days, and 30 days after the extruded foamed foamed sheet, the loss on heating after being left in a thermostat at 150 ° C. for 1 hour was determined, From there, the amount of the remaining blowing agent at that time was calculated. As shown in the figure, Examples 1 and 2 show almost the same foaming agent retention as the polystyrene resin foam sheet (Comparative Example 1), whereas Comparative Example 3 does not contain the ethylene-styrene copolymer. It can be seen that the foaming agent has escaped. In addition, in Example 3, it can be seen that the residual gas amount is slightly lower due to the effect of the amount of the polyethylene resin.

[0054]

According to the present invention, as described above, a tray for fruits and vegetables such as pears, peaches, and tomatoes can be supplied as a suitable product having both strength and flexibility (elasticity) enough to withstand the transportation of fruits and vegetables. . The effect of the present invention is to foam a mixed resin of a polystyrene resin, an ethylene-styrene copolymer and a polyethylene resin, so that the basic resin types are the same, and by changing the compounding ratio, the impact resistance is improved. It is possible to provide a material having excellent properties and a wide range of physical properties from a material having a rigidity close to that of a polystyrene resin to a material having flexibility close to a polyethylene resin foam. In addition, the foamability is not significantly reduced, and thermoforming is possible, and particularly fine and complicated shapes can be clearly formed. As a result, it can be used for various fruit and vegetable trays suitable for both hard and soft.

Attempts have been made to reduce the rigidity of polystyrene by adding styrene-butadiene rubber to a polystyrene-based resin or adding polyethylene.
The amount of the residual foaming agent is reduced, and the secondary moldability is deteriorated. Therefore, the amount added for the modification is limited, and it is difficult to maintain the secondary formability and to impart flexibility. However, according to the present invention, in order to obtain a tray for fruits and vegetables with high flexibility, in terms of weight ratio to the total amount of polystyrene-based resin, polyethylene-based resin and ethylene-styrene copolymer,
Even when the ratio of the polystyrene resin is about 50%, the extruding foamability and the secondary moldability do not significantly decrease.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of an embodiment of a fruit and vegetable tray of the present invention.

FIG. 2 is a cross-sectional view of the fruit and vegetable tray taken along line II-II in FIG.

FIG. 3 is a graph showing the relationship between the number of days after production and the amount of residual foaming agent in the foamed sheets of Examples and Comparative Examples.

[Explanation of symbols]

 A Fruit and vegetable tray 1 Storage recess

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takao Shimada 348-2 Hanwakuji-cho, Nara City, Nara Prefecture 310 Okura Heim Nara Aoyama F-term (Reference) 3E033 AA10 BA15 BA22 BB01 BB04 BB05 CA02 DA08 DD11 DE12 EA02 GA03 3E096 AA09 BA27 BB09 CA06 CB02 DA01 DA04 DC01 EA03X FA08 FA09 FA19 FA20 GA05 GA11

Claims (5)

[Claims] 1. A fruit and vegetable tray having a plurality of storage recesses, wherein the tray is formed from a foamed sheet of a mixed resin of a polystyrene resin, an ethylene-styrene copolymer, and a polyethylene resin. Tray for fruits and vegetables. 2. The foamed sheet has a density of 0.020 to 0.30.
2. The fruit and vegetable tray according to claim 1, wherein the tray is g / cm ³ . 3. A foam sheet according to claim 1, wherein the mixing ratio of the polystyrene resin, ethylene-styrene copolymer and polyethylene resin is 96 to 44% by weight of the polystyrene resin, 2 to 50% by weight of the ethylene-styrene copolymer, 3. The fruit and vegetable tray according to claim 1, wherein the content of the polyethylene resin is in the range of 2 to 30% by weight. 4. The tray for fruits and vegetables according to claim 1, wherein the composition of the ethylene-styrene copolymer is in the range of 50/50 to 20/80 by weight of ethylene and styrene. 5. An ethylene-styrene copolymer represented by the general formula:
(1): [Wherein, a, b and c each represent an integer of 1 or more. The fruit and vegetable tray according to any one of claims 1 to 4, which is represented by the following formula: