JP2000103016A - Polystyrene resin foam/polyolefin resin multilayered body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayered body which is prepd. by laminating and bonding a polyolefin resin layer on a polystyrene resin formed body with a high adhesive strength being durable for molding a deep container without using a special adhesive and has oil resistance and is inexpensive and recyclable. SOLUTION: A multilayered body prepd. by laminating a polyolefin resin layer Z on at least one face of a polystyrene resin foam layer X through an alloy layer Y is provided and this alloy layer Y consists of a mixture of a polystyrene resin and a polyolefin resin and the adhesive strength between this polystyrene resin foam X and the polyolefin resin layer Z is at least 40 gf/cm and the phase structural index PI value expressing mixed condition of the alloy layer Y is 0.7<PI<1.3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet-like or plate-like multilayer body in which a polyolefin-based resin is laminated on a polystyrene-based resin foam (hereinafter, also simply referred to as a multilayer sheet).

[0002]

2. Description of the Related Art Conventionally, expanded polystyrene sheets are thermoformed and widely used for various containers such as trays, lunch boxes, bowls, cups and the like. However, the expanded polystyrene sheet is inferior in oil resistance and solvent resistance, and its heat resistance is easily deformed when the container is heated in a microwave oven, and cannot be said to be high. For the purpose of improving these disadvantages of the expanded polystyrene sheet, a multilayer sheet in which a resin film of polyethylene, polypropylene, polyester, or the like is bonded to one or both sides of the expanded polystyrene sheet has been studied. In Japanese Utility Model Publication No. 59-17628, a polyolefin resin film is adhered to one or both sides of a foamed polystyrene sheet using a molten mixture of 40 to 60% by weight of a polystyrene resin and 60 to 40% by weight of a polyolefin resin as an adhesive. Although the composite sheet is shown in the figure, in the case of this composite sheet, the bonding strength of the adhesive is 30 because the mixing state of the adhesive is not controlled.
gf / cm or less, and when a sheet is formed into a deep container such as a bowl or a cup, there is a problem that the polyolefin-based resin film is partially peeled (delaminated) at the time of forming, and the multilayer has a stronger adhesive strength. A sheet was desired. In addition, only polyolefin resins have been studied for polyethylene, and no sheets having high heat resistance such as polypropylene have been studied. Japanese Utility Model Publication No. 62-20269 discloses a polyolefin resin on one or both sides of a foamed polystyrene sheet, using a thermoplastic rubber such as polybutadiene, polyisoprene, styrene-butadiene copolymer or a mixture of thermoplastic rubber and polyethylene as an adhesive. A composite sheet formed by bonding films is shown. However, these thermoplastic rubbers are more than three times more expensive than polystyrene and polyethylene, etc. In addition, in order to exhibit sufficient adhesive strength, the thermoplastic rubber is used alone or in a large amount. They had to be mixed and lacked cost merit. In addition, the adhesive strength when mixed with a polyolefin other than polyethylene, for example, polypropylene, is insufficient to bond polystyrene and polypropylene, and a multilayer sheet having stronger adhesive strength has been desired. 6
In JP-A-2-13784, one-part urethane and an ethylene / vinyl acetate copolymer are used as an adhesive, but effective recycling is not possible, heat resistance is low, and the odor of the ethylene / vinyl acetate copolymer is low. Had the problem of being strong.

[0003]

SUMMARY OF THE INVENTION The present invention does not use a special adhesive, but has a polyolefin resin layer on a polystyrene resin foam with a bonding strength high enough to withstand molding of a deep container such as a bowl. It is an object of the present invention to provide an inexpensive and recyclable polystyrene-based resin foam / polyolefin-based resin multilayer that is laminated and has oil resistance higher than that of a conventional polystyrene-based resin foam.

[0004]

Means for Solving the Problems As a result of various studies to solve the above problems, the present inventors have found that a polystyrene resin having an alloy layer in which a polystyrene resin and a polyolefin resin are mixed in a specific mixed state as an adhesive. By using a foam layer, it was found that an inexpensive multilayer body in which a polyolefin-based resin layer was laminated with high adhesive strength on at least one side without using a special adhesive was obtained, and the present invention was completed. . That is, according to the present invention, there is provided a multilayer body in which a polyolefin resin layer (Z) is laminated on at least one surface of a polystyrene resin foam layer (X) via an alloy layer (Y). (Y) is made of a mixed resin of a polystyrene resin and a polyolefin resin, and the adhesive strength between the polystyrene resin foam layer (X) and the polyolefin resin layer (Z) is 40 gf / cm.
A polystyrene-based resin foam / polyolefin-based resin multilayer body characterized by the above is provided. Further, at least one surface of the polystyrene resin foam layer (X),
Polyolefin resin layer (Z) via alloy layer (Y)
Are laminated, wherein the alloy layer (Y) is made of a mixed resin of a polystyrene-based resin and a polyolefin-based resin, and a phase structure index P representing a mixed state of the alloy layer (Y).
A polystyrene-based resin foam / polyolefin-based resin multilayer having an I value of 0.7 <PI <1.3 is provided.

[0005]

DETAILED DESCRIPTION OF THE INVENTION The polystyrene resin used in the present invention includes styrene homopolymers and copolymers, and the styrene monomer unit contained in the polymer is at least 25% by weight, preferably at least 25% by weight. 50% by weight or more. A preferred polystyrene resin used in the present invention is a resin containing at least 25% by weight of a structural unit represented by the following general formula (1) in the resin.

Embedded image In the general formula (1), R represents a hydrogen atom or a methyl group; Z represents a halogen atom or a methyl group;
Is 0 or an integer of 1 to 3. Examples of the polystyrene resin include polystyrene, rubber-modified polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene-acrylonitrile copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, and styrene-methyl methacrylate. Copolymer, styrene-ethyl methacrylate copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-maleic anhydride copolymer, polystyrene-polyphenylene ether copolymer, polystyrene and Examples thereof include a mixture with polyphenylene ether. Polyolefin resins such as polypropylene resins and high-density polyethylenes are considered in consideration of mixing these resins with styrene-conjugated diene block copolymer rubbers and hydrogenated products for the purpose of improving brittleness, etc. 20% by weight
Those blended in the following proportions can also be used. The heat resistance of the multilayer foam of the present invention can be improved by using a polystyrene resin having a Vicat softening point of 110 ° C. or higher. In this specification,
The Vicat softening point of the resin is JIS K7206 (the test load is A method, the rate of temperature rise of the heat transfer medium is 50 ± 5 ° C./hour)
Indicates the value obtained in.

The polystyrene resin used in the present invention has a melt viscosity of 190 ° C. and a shear rate of 100 sec.
Melt viscosity under the condition of ^{-1; 1} at 200 poise or more
Less than 00000 poise, preferably 1000 to 50
000 poise. If the melt viscosity is smaller than the above range, the molten resin extruded from the die at the time of molding the foam may hang, which may make molding difficult. on the other hand,
If it exceeds the above range, the viscosity is too high and the extrusion pressure increases, making extrusion molding difficult, and there is a possibility that a high-quality foam cannot be molded.

The polyolefin resin used in the present invention includes olefin homopolymers, copolymers (random copolymers, block copolymers, etc.) and blends. In the present invention, particularly from the viewpoint of heat resistance, those having a Vicat softening point of 112 ° C. or higher, and those having a softening point of 120 ° C. or higher (the upper limit of the softening point is not particularly limited;
It is about 0 ° C. ), In particular, the use of high-density polyethylene or polypropylene-based resin is preferred. The polypropylene resin includes propylene homopolymers, copolymers, blends, and the like. In the propylene copolymer, the copolymer component includes ethylene, butylene, and other α-olefins, and the α-olefin has 12 or less, preferably 8 or less carbon atoms. The content of the α-olefin as a copolymer component is preferably 20% by weight or less for a block copolymer and 8% by weight or less for a random copolymer. Further, in a blend of a polypropylene resin, the resin for blending includes a homopolymer of ethylene, ethylene and a carbon number of 3 to 3.
Copolymer with 12 α-olefins, having 4 to 6 carbon atoms
Α-olefin homopolymer and the like. In these blends, the content of the propylene component is 50% by weight or more, preferably 75% by weight or more. The propylene-based resin referred to in the present specification is obtained by graft-polymerizing a compound having at least one double bond (eg, an unsaturated carboxylic acid, a vinylsilane compound, etc.) to the propylene-based resin. The modified propylene resin is also included.

Next, the layer structure of the multilayer sheet of the present invention will be described in detail. The multilayer sheet of the present invention contains a polystyrene resin foam layer (X) (hereinafter, also simply referred to as a foam layer (X)). The density of the foam layer (X) is 0.035 to 0.7 g / cm ³ , preferably 0.03 to 0.7 g / cm ³ .
It is preferably from 5 to 0.5 g / cm ³ , and particularly preferably from 0.07 to 0.5 g / cm ³ for thermoforming. Also,
Its thickness is 0.5 to 10 mm, preferably 0.7 to 5 m
m, especially for thermoforming 0.7 to 4 mm. The open cell ratio of this foam layer (ASTM D285
6, Procedure C) is 90% or less, preferably 70% or less, more preferably 40% or less. If the density is less than the above range, not only does the strength of the molded product obtained by secondary molding of the multilayer sheet become insufficient, but also it causes insufficient elongation at the time of heating and vacuum forming, resulting in pores in the molded product. There is. On the other hand, if the density is higher than the above range, it is economically disadvantageous, and the heat insulation of the molded product is deteriorated, and when hot water is poured into the molded product such as a container, the container may be held by hand. become unable. If the thickness of the foam layer (X) is too small, the wall thickness of a molded product obtained by vacuum molding or the like becomes insufficient, resulting in inferior strength and heat insulation. On the other hand, if the thickness is too large, uneven heating inside and outside the sheet is likely to occur during heating vacuum forming, and precise temperature control is required. Since the open cell ratio of the foam layer (X) affects the secondary foaming property at the time of thermoforming and the quality (physical properties such as strength) of the obtained secondary molded product, it is preferable to specify the ratio as described above.

The multilayer sheet of the present invention contains an alloy layer (Y) formed on at least one side of the foam layer (X). The alloy layer (Y) is mainly composed of a mixed resin of a polystyrene resin and a polyolefin resin, and has a weight ratio of the polystyrene resin to the polyolefin resin of 95: 5 to 30:70, and more preferably 90:10 to 4
The ratio is preferably 0:60, particularly preferably 85:15 to 55:45. The alloy composed of the polystyrene resin and the polyolefin resin contains 50% by weight or more of the alloy layer. As the polyolefin resin used for the alloy layer (Y), the same resin as the polyolefin resin used for the polyolefin resin layer (Z) laminated on the alloy layer (Y), or the same kind that can be thermally fused. Is preferably used. When the weight ratio of the polystyrene resin in the alloy layer (Y) exceeds the above range, the adhesive strength between the alloy layer (Y) and the foam layer (X) is satisfied, but the alloy layer ( There is a possibility that the adhesive strength between Y) and the polyolefin-based resin layer (Z) becomes insufficient. On the other hand, when the weight ratio of the polystyrene-based resin is lower than the above range, conversely, although the adhesive strength between the alloy layer (Y) and the polyolefin-based resin layer (Z) is satisfied, the foam layer (X ) And the alloy layer (Y) may be insufficient in adhesive strength. The thickness of the alloy layer (Y) is 15 to 200.
As the thickness increases within the range of μm, the adhesive force tends to increase, and the thickness of the alloy layer (Y) is preferably from 20 to 15 μm.
0 μm, and its ratio to the thickness of the foam layer (X) is 3 to 50%, preferably 5 to 40%. When the thickness of the alloy layer (Y) is smaller than the above range, the adhesiveness becomes insufficient. On the other hand, when the thickness exceeds the above range, the open cell ratio of the foam layer tends to increase, and the cost increases. Becomes

[0010] The multilayer sheet of the present invention contains a polyolefin resin layer (Z) formed on the upper surface of the alloy layer (Y). This polyolefin resin layer (Z)
The thickness is 0.01 to 1 mm, preferably 0.015 to 0.8 mm, more preferably 0.015 to
0.35 mm, and its ratio to the thickness of the foam layer (X) is 3 to 50%, preferably 5 to 40%. If the thickness of the polyolefin-based resin layer (Z) is smaller than the above range, it is not preferable because holes or tears occur in the sheet during secondary molding. On the other hand, if the thickness is too large, not only does the cost increase, but also the difference between the heat forming time of the film layer (Z) and the heat forming time of the foam layer (X) becomes too large, and the film layer (Z When the multilayer sheet is formed with the optimal heating time for the foam layer (X)
Melts. As the polyolefin-based resin layer (Z) formed on the upper surface of the alloy layer (Y), a high-density polyethylene or a polypropylene-based resin is preferable in terms of heat resistance and appearance, and a resin layer (Z) made of high-density polyethylene was formed. In this case, when the surface of the laminated sheet has a matte appearance, and when the resin layer (Z) made of a polypropylene resin is formed, the laminated sheet having excellent surface gloss can be obtained. Further, a high-density polyethylene or polypropylene-based random copolymer is preferred from the viewpoint of excellent heat moldability, particularly excellent uniformity of elongation of the laminated sheet related to formability such as deep drawing without unevenness in elongation of the laminated sheet. Further, from the viewpoint of the releasability of the laminated sheet after the die molding in the thermoforming step,
It is preferable to laminate a polyolefin-based resin layer (Z) made of a polyolefin-based resin having a half-crystallization time at 00 ° C. of 40 seconds or less, and more preferably 30 seconds or less. The term “half-crystallization time” as used herein refers to a crystallization rate measuring device (MK-801 type manufactured by Kotaki Shoji Co., Ltd.)
A resin sample heated to 0 ° C. can be put into a crystallization bath set at 100 ° C. for measurement. The measurement sample is prepared in the form of a film. In this case, the thickness of the film is 0.1 ± 0.02 mm, and the dimensions of the film are 15 × 15 mm square. The sample sandwiched between the microscope cover glass is used as a measurement sample. Also, for the brightness setting of the light source lamp, the indicated value is set to 3V.
And The crystallization rate measuring device manufactured by Kotaki Shoji Co., Ltd. is a device for determining the degree of crystallinity from the relationship between the crystallization of the sample and the birefringence of light, and the half-crystallization time referred to in the present specification is the measurement method From the obtained curve on the graph shown in FIG. 1, a value A at which the amount of light due to birefringence is constant is read from the vertical axis on the graph, and the value is multiplied by 0.5 to correspond to the value B on the vertical axis on the graph. This value is obtained as the value C on the horizontal axis of the curve on the graph.

In the multilayer sheet of the present invention, a polyolefin resin layer (Z) can be laminated on both sides of the foam layer (X) via the alloy layer (Y). There is no need to laminate the polyolefin-based resin layer (Z) via (Y), and one side of the foam layer (X) can be an unlaminated surface,
Further, a resin layer such as a polystyrene resin layer (L) or an alloy layer (Y) can be laminated on one surface of the foam layer (X). In the polystyrene-based resin layer (L) and the alloy layer (Y), the thickness is 15 to 350 μm, preferably 20 to 250 μm, and the ratio to the thickness of the foam layer (X) is 3 to 50%, preferably 5 to 40%. In the case where the polystyrene resin layer (L) is laminated on one surface of the foam layer (X), the resin layer (L) is excellent in printability and glossiness, so that it can be used as a print surface. . On the other hand, when the alloy layer (Y) is laminated on one side of the foam layer (X), the alloy layer (Y) has excellent printability and glossiness,
Since it can be advantageously used as a printing surface and two alloy layers (Y) formed on both sides of a foam layer (X) by a co-extrusion method can be simultaneously laminated using the same extruder, production Excellent in properties.

In the multilayer sheet of the present invention, a compatibilizer can be added to the alloy layer (Y). As the compatibilizer in this case, any one can be used as long as it can compatibilize the polystyrene resin and the polyolefin resin, and various conventionally known ones can be used. As such a material, use of a styrene-based thermoplastic elastomer is particularly preferable. The styrene-based thermoplastic elastomer includes SEBS-based and SEPS-based thermoplastic elastomers, SBS-based and SIS-based thermoplastic elastomers, and the like. The SBS or SIS type has a polystyrene crystal phase as a hard segment, and has a structure in which polybutadiene or polyisoprene is block copolymerized as a soft segment. On the other hand, SEBS-based and SEPS-based
Polybutadiene contained in S type and SIS type,
Highly hydrogenated polyisoprene to saturate double bonds in its main chain. These SEBS systems and S
For styrenic thermoplastic elastomers such as EPS-based, SBS-based and SIS-based, "plastic age",
The details are described on pages 101 to 106 (June 1985).

The compatibilizer is alloy 1 in the alloy layer (Y).
0.1 to 25 parts by weight, preferably 0.1 to 25 parts by weight, per 100 parts by weight.
It is preferable to add 5 to 10 parts by weight. Also,
It is preferable to add a rubber component such as a styrene-based thermoplastic elastomer to the alloy layer. The addition of the compatibilizer and the rubber component further improves the adhesiveness between the foam layer (X) and the resin layer (Z), and the impact strength and brittleness of the multilayer sheet. The addition of the rubber component to the alloy layer is 2 per 100 parts by weight of the alloy.
It is preferred to add in a proportion of up to 30 parts by weight. The rubber component includes the above-mentioned styrene-based thermoplastic elastomer, butadiene rubber, ethylene-propylene rubber and the like, and a styrene-based thermoplastic elastomer is particularly preferred.

In the multilayer sheet of the present invention, the adhesive strength between the foam layer (X) and the polyolefin-based resin layer (Z) is at least 40 gf / cm, particularly preferably 1 gf / cm or more.
It has a large adhesive strength of at least 00 gf / cm, and more preferably at least 150 gf / cm. The upper limit of the adhesive strength is
Usually, it is about 500 gf / cm. The multilayer sheet having such a large interlayer adhesive strength was first developed by the present inventors.

The fact that the interlayer adhesive strength of the multilayer sheet of the present invention has a large value as described above means that the alloy layer (Y)
Has a phase structure index PI value of 0.7 to 1.3, preferably 0.1 to 1.3.
This is due to being in the range of 8 to 1.2. The phase structure index PI value of the alloy layer (Y) indicates a mixed state of the polystyrene resin and the polyolefin resin of the alloy layer, and is defined by the following formula (1).

(Equation 1) In the above formula (1), φ _A is the volume fraction of the polystyrene resin phase in the alloy layer, η _A is 190 ° C., and the shear rate is 10
Melt viscosity of polystyrene resin at ⁰ sec ^-1 , φ
_B is the volume fraction of the polyolefin resin phase in the alloy layer,
η _B is the melt viscosity of the polyolefin resin at 190 ° C. and a shear rate of 100 sec ⁻¹ .

According to the study of the present inventors, when the PI value of the alloy layer (Y) is smaller than the above range, the polyolefin-based resin in the alloy layer is covered with the polystyrene-based resin and is hardly exposed to the bonding surface. Although the adhesive strength between the foam layer (X) and the alloy layer (Y) can be satisfied, the adhesive strength between the alloy layer (Y) and the polyolefin resin layer (Z) becomes insufficient, and the multilayer sheet Delamination is likely to occur when molded into a molded article such as a container (especially a deep thing such as a bowl) obtained by thermoforming the resin. On the other hand, when the PI value exceeds 1.3, the polystyrene-based resin in the alloy layer is covered with the polyolefin-based resin and becomes difficult to be exposed on the adhesive surface, and the polyolefin-based resin layer (Z) and the alloy layer (Y) are hardly exposed. Is satisfactory, but the adhesive strength between the alloy layer (Y) and the foam layer (X) is insufficient, so that when forming a multilayer sheet into a molded article such as a container (especially a deep bowl such as a bowl). Delamination easily occurs. As a result, the PI value is 0.7 to 1.3.
Within this range, the adhesive strength between the foam layer (X) and the polyolefin resin layer (Z) becomes excellent.

When the compatibilizer is added to the alloy layer, the PI value is calculated by determining which of the polyolefin resin and the polystyrene resin has the better compatibility. (For example, S
The PI value is determined by the above equation (1) using the EBS type as a component of the polyolefin resin and the SBS type as the component of the polystyrene resin. The multilayer sheet of the present invention can be manufactured by a conventionally known method. As a typical method, a foam layer (X) is manufactured in advance, and then the polyolefin-based resin layer (Z) and the alloy layer (Y) are supplied from another extruder and bonded on a manufacturing line or another line. A method of producing a foam layer (X), introducing a polyolefin resin film as a polyolefin resin layer (Z) on a production line or another line,
A method in which the alloy layer (Y) is supplied from another extruder and bonded, and an alloy layer (Y) and a polyolefin-based resin layer (Z) are provided on at least one surface of the foam layer (X) by a multi-layer coextrusion method and extruded. There are manufacturing methods and the like. Among them, the multilayer sheet obtained by the multilayer co-extrusion method has a simpler process and can be reduced in cost as compared with other methods, and the foam layer (X), the alloy layer (Y), and the alloy layer (Y) It is preferable because the adhesive strength between the resin and the polyolefin-based resin layer (Z) increases. Particularly, as a method for producing the multilayer sheet of the present invention in which a polystyrene resin such as high impact polystyrene (HIPS) is laminated on one surface, a copolyextrusion method or the like is used to form a polystyrene resin foam on one surface via an alloy layer. Obtaining a multilayer sheet laminated with an olefin-based resin, and then laminating a high-impact polystyrene melt on a surface of the foam layer where the polyolefin-based resin layer is not laminated by using an T-die by an extrusion lamination method; A method of co-extruding a foam layer, an alloy layer, a resin layer, and a polystyrene-based resin layer is employed. The polystyrene-based resin, polyolefin-based resin, compatibilizer, and the like used for the alloy layer (Y) may be dry-blended in the form of pellets, and then directly put into the inlet of the extruder, or may be melt-kneaded in advance and used. .

As the foaming agent used for producing a polystyrene resin foam, propane, n-butane, i-
Butane, a mixture of n-butane and i-butane, an aliphatic hydrocarbon such as pentane and hexane, a cycloaliphatic hydrocarbon such as cyclobutane and cyclopentane, trichlorofluoromethane, dichlorodifluoromethane, 1,1-difluoroethane , 1,1-difluoro-1-chloroethane, 1,
Examples include halogenated hydrocarbons such as 1,1,2-tetrafluoroethane, methyl chloride, ethyl chloride, and methylene chloride, and mixtures thereof. Furthermore, examples of the decomposable foaming agent include azodicarbonamide, dinitrosopentamethylenetetramine, azobisisobutyronitrile, sodium bicarbonate and the like. Also,
An inorganic gas such as carbon dioxide may also be used. These foaming agents can be appropriately mixed and used. Among them, it is preferable to use one which does not affect the environment such as destruction of the ozone layer which does not contain hydrogen halide. The amount of the foaming agent to be used is not particularly limited, but can be freely selected from about 0.01 to 0.1 mol per 100 g of the resin with respect to the target sheet density.

The resin composition used in the multilayer sheet of the present invention may contain various additives which are usually added to a polystyrene resin and a polyolefin resin, if necessary, as long as the object of the present invention is not significantly impaired. For example, nucleating agents,
Antioxidants, heat stabilizers, antistatic agents, conductivity-imparting agents, weathering agents, ultraviolet absorbers, coloring agents, flame retardants, inorganic fillers and the like can be added.

[0020]

Next, the present invention will be described in more detail with reference to examples.

Examples 1 to 20, Comparative Examples 1 to 3 Multilayer sheets having the structures shown in Tables 1, 2, 5 and 6 were prepared. Tables 1, 2, 5 and 6 also show the density of the multilayer sheet (g / cm ³ ), the thickness of the sheet (mm), and the type of multilayer sheet manufacturing method employed for the production. Further, Tables 1, 2, 5 and 6 show the oil resistance of the multilayer sheet, the adhesive strength (gf / cm) of the polyolefin resin layer (Z ¹ or Z ² ), and the open cell ratio of the foam layer. (%)showed that.

In the multilayer sheets shown in Table 1, Table 2, Table 5 and Table 6, the polyolefin resin (Z ¹ ) indicates the surface layer, and the polyolefin resin layer (Z ² ) indicates the back layer. In the adhesive strength, Z ¹ / X indicates the adhesive strength between the polyolefin resin layer (Z ¹ ) forming the surface layer and the foam layer (X), and Z ² / X indicates the polyolefin resin layer forming the back layer. The adhesive strength between the resin layer (Z ² ) and the foam layer (X) is shown.

The specific contents of the types of production methods of the multilayer sheet shown in Tables 1, 2, 5 and 6 are as follows. The resin temperatures shown in Table 1, Table 2, Table 5 and Table 6 are resin temperatures at the time of extrusion from a die (die) of an extruder. (After lamination) Two extruders having a diameter of 65 mm and a diameter of 90 mm were used as extruders, and the die (diameter) was 8 mm in diameter.
One having a cylindrical gap of 4 mm and a thickness of 0.5 mm was used. A predetermined amount of resin and additives were heated and kneaded in an extruder having a diameter of 65 mm from a material input port with respect to 100 parts by weight of the resin in an amount shown in Table 3 or Table 4, and the resin mixture adjusted to about 200 ° C. Then, the foaming agent and the amount shown in Table 3 or Table 4 were press-fitted, then supplied to an extruder having a diameter of 90 mm, adjusted to the resin temperature shown in Table 1 or 2, and the resin was extruded from a die. The extruded cylindrical resin has a diameter of 20
It was cut open along the 0 mm cooled cylinder in the pull-out direction to obtain a polystyrene resin foam sheet, and the foam sheet was wound up. Table 1 or Table 2 was added to the obtained foamed sheet.
Was laminated through an alloy layer shown in Table 1 or Table 2 to obtain a multilayer sheet. The alloy layer is heated by an extruder having a diameter of 50 mm from a raw material inlet to a predetermined amount of resin shown in Table 1 or Table 2 and, if necessary, an amount of compatibilizer shown in Table 1 or Table 2 per 100 parts by weight of alloy. It was kneaded and extruded at 200 ° C. from a T-die having a width of 650 mm. (Co-extrusion) Two extruders having a diameter of 65 mm and 90 mm as an extruder for a foam layer, an extruder having a diameter of 50 mm as an extruder for a polyolefin resin layer, and a 40 mm diameter for an alloy layer. An extruder was used, and a die having a diameter of 84 mm and a thickness of 0.5 mm and having a cylindrical gap was used as a die. The foam layer was heated and kneaded in a 65 mm diameter extruder with a predetermined amount of resin and additives from the raw material inlet at the amounts shown in Table 3, Table 4, Table 7, or Table 8 per 100 parts by weight of the resin. The blowing agent and the amount shown in Table 3, Table 4, Table 7 or Table 8 are press-fitted into the resin mixture adjusted to, and then fed to an extruder having a diameter of 90 mm, and Table 1, Table 2, Table 5, and The resin temperature was adjusted as shown in Table 6. On the other hand, the polyolefin-based resin layer is supplied from an extruder having a diameter of 50 mm, and the alloy layer is supplied from one of the extruders having a diameter of 40 mm to one or both sides of the melt for forming a polystyrene-based resin foam layer, as required, and the foam is formed inside the die. It was combined with the melt for layer formation and coextruded. In addition, the compatibilizing agent was added to the alloy layer as needed, as shown in Table 3, Table 4, Table 7, or Table 8 per 100 parts by weight of the alloy of the polystyrene resin and the polystyrene resin. The extruded cylindrical resin has a diameter of 2
The multilayer sheet was wound by pulling it along a 00 mm cooled cylinder.

Tables 3, 4, 7 and 8 show specific examples of the foam layer (X), the alloy layer (Y ¹ , Y ² ) and the polyolefin resin layer (Z ¹ , Z ² ) constituting the multilayer sheet. The contents are shown below. In the table, the amount (% by weight) of the PS resin or the PO resin in the alloy layer is 100% by total weight of the PS resin and the PO resin.
The value is based on% by weight. In Examples 14 and 18, 20 parts by weight of a resin Y described later as a rubber component was added to the alloy layer based on 100 parts by weight of the mixed resin of the PS resin and the PO resin. Also, in Example 20, a resin Z described later was used as a rubber component in the alloy layer with a PS resin and a PO resin.
25 parts by weight were added to 100 parts by weight of the mixed resin with the resin.

The PS indicated by the reference numeral for the foam layer (X)
The specific contents of the resin (polystyrene resin) are as shown in the latter half. The talc compounded in the PS resin is High Filler # 12 manufactured by Matsumura Sangyo Co., Ltd. Further, in the blowing agent indicated by the reference numeral, B is 70% by weight of n-butane and iso.
A butane mixture consisting of 30% by weight of butane,
p represents an n- pentane, CF40S is Dainichi Seika Co., Ltd. "Hydrocerol CF40S] indicating the (chemical blowing agent). alloy layer (Y ^1, Y ²⁾ with respect to PO resin (polyolefin resin) and compatibilizer The specific contents of the agent are as shown in the latter half, wherein the alloy layer (Y ¹ ) and the alloy layer (Y ² ) have the same component composition.

PO layer (polyolefin layer) (Z ¹ , Z ² )
The specific contents of the PO resin indicated by reference numerals are as shown in the latter half. The component composition of the PO layer (Z ¹ ) is the same as that of the PO layer (Z ² ).

The method for evaluating the oil resistance and the adhesive strength of the multilayer sheet is as follows. (Oil resistance) 0.025 ml of rice-cooked seasoning oil (fresh roll white, manufactured by Rolling Co., Ltd.) was dropped in the center of a 25 mm × 40 mm sheet, uniformly spread, and then heated to 80 ° C.
For 5 minutes and the change before and after was examined. ○ ・ ・ ・ No change × ・ ・ ・ There is erosion on the sheet surface (Adhesion strength) The adhesion strength between the polystyrene resin foam layer (X) and the polyolefin resin layer (Z) is 25 mm wider than the multilayer sheet. Cut out a piece and follow JIS Z02
According to 37, the peeling speed condition is 300 mm / min 90
The value (g / 25 mm) determined by the peel test was divided by 2.5 to obtain the adhesive strength (g / cm).

The specific contents of the resin indicated by reference numerals in Tables 1 to 8 are as follows. (1) Resin A “HH32” (general purpose polystyrene (GPPS), manufactured by Idemitsu Petrochemical Co., Ltd., melt viscosity 20400 poise, density 1.0
(5 g / cm ³ ) (2) Resin B “HH30J” (GPPS, melt viscosity 12300 poise, density 1.05 g / cm ³ ) manufactured by Idemitsu Petrochemical Co., Ltd. (3) Resin C “Stylon 679” (GPPS manufactured by Asahi Kasei Corporation) , Melt viscosity 8300 poise, density 1.05 g / cm ³ ) (4) Resin D “G9001” (styrene-methacrylic acid copolymer, melt viscosity 26,800 poise, density 1.05 g, manufactured by Asahi Kasei Corporation)
/ Cm ³ , Vicat softening point 110 ° C. or higher) (5) Resin H “PM761A” (propylene-ethylene block copolymer, melt viscosity 6600 poise, density 0.9 g / cm ³ , Vicat softening point 120, manufactured by Nippon Polyolefin Co., Ltd.) (C), semi-crystallization time (100 ° C.) 7 seconds) (6) Resin I “MK211” (propylene-ethylene block copolymer, melt viscosity 8,000 poise, density 0.9 g / cm ³ , Vicat, manufactured by Nippon Polyolefin Co., Ltd.) (7) Resin J "E250G" (propylene-ethylene block copolymer, melt viscosity 15700 poise, density 0.9 g, manufactured by Idemitsu Petrochemical Co., Ltd.) / cm ^3, a Vicat softening point 120 ° C. or higher, half-crystallization time (100 ° C.) or less 10 seconds) (8) resin K Japan polyolefins Ltd., "KB175A" (high-density polyethylene, melt viscosity 19100 poise, density 0.95
(7 g / cm ³ , Vicat softening point of 120 ° C. or more, semi-crystallization time (100 ° C.) of 10 seconds or less) (9) Resin V “Toughtec H1041” (manufactured by Asahi Kasei Corporation) (hydrogenated styrene butadiene styrene elastomer, melt viscosity 290)
00 poise, density 0.9 g / cm ³ ) (10) Resin W “MODIPA A3100” manufactured by NOF Corporation (styrene graft polypropylene, melt viscosity 3600 poise, density 0.94 g / cm ³ ) (11) Resin M Chisso “F8188” (propylene-ethylene random copolymer, melt viscosity 6300 poise (190
° C), density 0.9g / cm ³ , Vicat softening point 120 ° C
(Semi-crystallization time (100 ° C.) 25 seconds) (12) Resin N “310E” (manufactured by Idemitsu Petrochemical Co., Ltd., high-density polyethylene, melt viscosity 16500 poise, density 0.965 g / c)
m ³ , Vicat softening point 130 ° C., half-crystallization time (100
(C) 10 seconds or less) (13) Resin O "580 MB" (high-density polyethylene, melt viscosity 19000 poise, density 0.964 g / c, manufactured by Idemitsu Petrochemical Co., Ltd.)
m ³ , Vicat softening point 128 ° C., half-crystallization time (100
(° C) 10 seconds or less) (14) Resin P “J5051HP” (made by Idemitsu Petrochemical Co., Ltd.)
Ethylene block copolymer, melt viscosity 2600 poise,
(Density 0.9 g / cm ³ , Vicat softening point 151 ° C., semi-crystallization time (100 ° C.) 10 seconds or less) (15) Resin Q manufactured by Idemitsu Petrochemical Co., Ltd., “210JZ” (high-density polyethylene, melt viscosity 8200 poise, Density 0.968g / cm
^3. Vicat softening point 129 ° C, half crystallization time (100
° C.) 5 seconds) (16) Resin R manufactured by Nippon Polyolefin Co. "PM731M] (propylene - ethylene random copolymer, melt viscosity 6100 poise, density 0.9 g / cm ^3, a Vicat softening point 120 ° C. or higher, half-crystallization time (17 ° C.) (17 ° C.) (17) Resin X “TUFTEC L512” (hydrogenated styrene butadiene styrene elastomer, manufactured by Asahi Kasei Corporation, melt viscosity 2900)
Poise, density 0.91 g / cm ³ ) (18) Resin Y “Tafprene 125” (styrene butadiene styrene elastomer, melt viscosity 12100 poise, manufactured by Asahi Kasei Corporation)
Density 0.95g / cm ³⁾ (19) Resin Z Phillips "K Resin KR05" (styrene-butadiene-styrene elastomers, the melt viscosity 11500 poise, density 1.01 g / cm ³⁾

The melt viscosities given for the above resins were measured as follows. (Melt Viscosity of Resin) The melt viscosity under the conditions of a shear rate of 100 sec ^-1 was such that the nozzle inner diameter (D) was 1.0 mm, and L / D =
The measurement was carried out with a Cheast Corporation Leovis 2100 using a 10 nozzle (L is a nozzle length (mm)) at a resin temperature of 190 ° C.

The PI value of the alloy layer is calculated by the above equation.
(1) was used. Compatibilizer if added
Is calculated as the resin component having the better compatibility. Example 2
An example of calculation in the case of is shown below. Resin used: HH32 (PS resin) (melt viscosity 2040
0 poise, density 1.05g / cm ^Three) PM761A (PO resin) (melt viscosity 6600 poi)
) Tuftec H1041 (compatibilizer) (melt viscosity 290)
00 poise) The tough tech is polypropylene rather than polystyrene
Calculated as PP component because of good compatibility with (PP)
You. First, the melt viscosity of the PP component is determined. For this
Is tough tech (density 0.9g / cm^Three) And PP (density)
0.9g / cm^Three) Is determined. This
Is 5:25 (weight ratio),
The volume ratio is 16.7: 83.3. Viscosity of PP component = 10^α  However, α = [{log (viscosity of PP: 6600) × 83.3 +
log (Tufftec viscosity: 29000) x 16.7．
/ 100] Therefore, the viscosity of the PP component is 8450. Volume fraction of PP component: [{(25 + 5) /0.9} / [{(25 + 5) /0.9} +
(75 / 1.05)]] × 100 = 32 PS volume fraction: [(75 / 1.05) / [{(25 + 5) /0.9} + (75)
/1.05)]]×100=68 Therefore, the PI value is PI = (viscosity of PS component: 20400 × volume of PP component)
(Fraction: 32) / (viscosity of PP component: 8450 × PS component)
Volume fraction: 68) = 1.13

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

[Table 3]

[0034]

[Table 4]

[0035]

[Table 5]

[0036]

[Table 6]

[0037]

[Table 7]

[0038]

[Table 8]

[0039]

According to the present invention, a polyolefin resin layer is laminated and bonded on a polystyrene resin foam with a high adhesive strength capable of withstanding molding of a deep container such as a bowl without using a special adhesive. An inexpensive and recyclable polystyrene resin foam / polyolefin resin multilayer having oil resistance higher than that of the polystyrene resin foam can be obtained. In particular, heat resistance is improved by laminating and bonding a resin layer made of a polyolefin resin having a Vicat softening point of 112 ° C. or higher on a polystyrene resin foam. In addition, by using a foam made of a polystyrene resin having a Vicat softening point of 110 ° C. or higher, particularly excellent heat resistance can be obtained regardless of the Vicat softening point of the base resin of the polyolefin resin layer.

[0040]

[Brief description of the drawings]

FIG. 1 is a diagram showing a graph of crystallization time measurement.

[Explanation of symbols]

 (I) Light intensity curve correlated with crystallization (II) Crystallization bath temperature a Time during which the amount of light due to birefringence is constant A Amount of light due to birefringence at a B B A × 0.5 C semi-crystal Crystallization time D Crystallization bath set temperature

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] April 15, 1999 (1999.4.1
5)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 6

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Claim 7

[Correction method] Change

[Correction contents]

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takashi Muroi 1-73 Yonishi-cho, Utsunomiya City, Tochigi Prefecture 205 Sun Corp. Yonishi 205 (72) Inventor Kenichi Takase 1244-10 Sento, Kanuma City, Tochigi Prefecture La Foret Up B-102 F term (reference) 4F100 JB07 JJ03 JK06 YY00

Claims (10)

[Claims] 1. A multilayer body in which a polyolefin resin layer (Z) is laminated on at least one surface of a polystyrene resin foam layer (X) via an alloy layer (Y), wherein the alloy layer (Y) Is composed of a mixed resin of a polystyrene resin and a polyolefin resin, and the adhesive strength between the polystyrene resin foam layer (X) and the polyolefin resin layer (Z) is 40 gf / cm or more. Polystyrene resin foam / polyolefin resin multilayer. 2. A multilayer body in which a polyolefin resin layer (Z) is laminated on at least one surface of a polystyrene resin foam layer (X) via an alloy layer (Y), wherein the alloy layer (Y) Is a mixed resin of a polystyrene-based resin and a polyolefin-based resin, and a phase structure index PI value representing a mixed state of the alloy layer (Y) is 0.7 <PI <1.3. Resin foam / polyolefin resin multilayer. 3. The weight ratio between the polystyrene resin and the polyolefin resin in the alloy layer (Y) is 95: 5 to 30:
The polystyrene-based resin foam / polyolefin-based resin multilayer according to claim 1 or 2, wherein 4. A polyolefin resin layer (Z) is laminated on one surface of a polystyrene resin foam layer (X) via an alloy layer (Y), and the other surface of the polystyrene resin foam layer (X) is provided. The polystyrene-based resin foam / polyolefin-based resin multilayer according to claim 1, wherein a polystyrene-based resin layer (L) is laminated on the polystyrene-based resin foam. 5. A polyolefin resin layer (Z) is laminated on one side of a polystyrene resin foam layer (X) via an alloy layer (Y), and the other side of the polystyrene resin foam layer (X) is provided. The polystyrene-based resin foam / polyolefin-based resin multilayer according to claim 1, wherein an alloy layer (Y) is laminated thereon. 6. A compatibilizer is added to the alloy layer (Y),
The amount of the compatibilizer added is 0.1 to 25 parts by weight per 100 parts by weight of the alloy of the polystyrene resin and the polystyrene resin in the alloy layer (Y). The polystyrene-based resin foam / polyolefin-based resin multilayer according to any one of the above. 7. A rubber component is added to the alloy layer (Y),
The rubber component is added in an amount of 2 to 30 parts by weight per 100 parts by weight of the alloy of the polystyrene resin and the polystyrene resin in the alloy layer (Y). Polystyrene-based resin foam / polyolefin-based resin multilayer body according to (1). 8. The alloy layer (Y) has a thickness of 15 to 200 μm.
The polystyrene-based resin foam / polyolefin-based resin multilayer according to any one of claims 1 to 7, wherein m is m. 9. The polystyrene resin foam according to claim 1, wherein the polystyrene resin foam layer (X) and the alloy layer (Y) are laminated by a co-extrusion method. Body / Polyolefin resin multilayer body. 10. The polystyrene resin foam / polyolefin resin according to claim 1, wherein the polyolefin resin layer (Z) is made of a polyolefin resin having a Vicat softening point of 112 ° C. or higher. Multi-layer body.