JP3028101B2 - Peelable thermoplastic resin laminated foam sheet, method for producing the same, and molded product thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a peelable thermoplastic resin laminated foam sheet, a method for producing the same, and a molded product thereof.

[0002]

2. Description of the Related Art Expanded polystyrene, expanded polyester,
Trays and packaging containers (hereinafter referred to as molded products) molded from thermoplastic resin foam sheets such as foamed polyolefins are inexpensive, pure white, and have a clean feeling, so that vegetables, meat, fish, and cooked foods can be used. Widely used as food containers and packaging containers.

Recently, it has become important to collect and reuse these molded articles which have been used in large quantities from the viewpoint of waste disposal and resource saving. However, the inner surfaces of these molded articles are dirty and cannot be reused as they are. When storing foods such as fresh noodles and ham, a gas barrier film is attached to a foamed sheet in order to improve the freshness. As described above, since the film is made of a different material, it is necessary to separate the film, and it is difficult to collect and reuse the molded product.

As one of these recovery methods, it has been considered that a film is stuck instead of cleaning the inner surface of the molded article, and after use, the film is peeled off and the molded article itself is reused (Japanese Utility Model Application Laid-open No. Hei 4 (1994)). JP-A-38942, 3-16
No. 214, see Japanese Utility Model Application No. 4-74081). However,
In the molded product, the film is stuck with an adhesive, but the peel strength of the film greatly varies,
Adhesive strength is partially strong or weak. For this reason, when using a thin and weak film, the film is cut during peeling, and when the adhesive strength is weak, it peels off during use, and when the adhesive strength is large, it can not be peeled off even after use. There was a problem.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned technical problems. That is, an object of the present invention is to provide a peelable thermoplastic resin laminated foam sheet in which a thermoplastic resin foam sheet and a thermoplastic resin film having a small variation in peel strength are laminated. Another object of the present invention is to provide a thermoplastic resin foam sheet,
An object of the present invention is to provide a continuous and economical method for producing a peelable thermoplastic resin laminated foamed sheet by fusing and laminating a thermoplastic resin film. Another object of the present invention is to provide a more continuous and economical peelable thermoplastic resin laminated foam sheet by laminating a thermoplastic resin foam sheet and a thermoplastic resin film by coextrusion. It is intended to provide a manufacturing method.

Another object of the present invention is to provide a releasable thermoplastic resin laminated sheet obtained by laminating a thermoplastic resin foam sheet and a thermoplastic resin film, which is obtained by thermoforming. The present invention provides a molded article having a small variation in peel strength between a film and a foam. Another object of the present invention is to provide a molded article which can be used by removing the inner film of the molded article after use, and recovering the molded article main body for reuse. In order to achieve the above object, the present inventors have made intensive studies and have found that the cell diameter and surface smoothness of a thermoplastic resin foam sheet are adjusted.

[0007]

That is, the gist of the present invention is as follows.
The diameter of the bubble in the minor axis direction on the surface is 0.005.
0.5 mm and surface smoothness Rmax is 5 to 200 μm
A thermoplastic resin foam sheet and a thermoplastic resin film are laminated, and the peel strength between the thermoplastic resin foam sheet and the film is 5 to 400 g / 25 mm width. The size of the thermoplastic resin laminated foam sheet and the diameter of the bubbles in the minor axis direction on the surface is 0.00
5 to 0.5 mm and surface smoothness Rmax of 5 to 200 μm
m by laminating a thermoplastic resin foam sheet and a thermoplastic resin film so that the peel strength between the thermoplastic resin foam sheet and the film is 5 to 400 g / 25 mm width. A possible method for producing a laminated thermoplastic resin foam sheet, the diameter of bubbles on the surface in the minor axis direction is 0.005 to 0.5 mm, and the surface smoothness Rmax
A thermoplastic resin foam sheet having a thickness of 5 to 200 μm and a thermoplastic resin film are laminated, and the peel strength of the film is from a peelable thermoplastic resin laminated foam sheet having a width of 5 to 400 g / 25 mm. A molded article characterized by being molded.

[0008] In the present invention, the expanded polystyrene-based sheath
A thermoplastic resin foam sheet (hereinafter referred to as a foam sheet) such as a sheet, a foamed polyester-based sheet, or a foamed polyolefin-based sheet generally has an elliptical or circular shape as viewed from the sheet surface. In the case of an oval shape having bubbles, the directions of the major axis and the minor axis are regularly aligned with the MD and TD. If the bubble is elliptical, the diameter of the bubble in the minor axis direction on the surface is
Alternatively, when the bubble is circular, the diameter of the bubble on the surface is 0.
005 to 0.5 mm and surface smoothness Rmax is 5 to 20
0 μm. By defining in this way, it was possible to reduce the variation in the peel strength of the laminated films. The variation in the peel strength is 3% of the average value.
It is within 0%.

In the present invention, the size d of the diameter of the bubbles in the minor axis direction on the surface is determined by determining whether the film is separated from the surface of the foamed sheet or, if laminated, by peeling the film.
The number of bubbles over 0 mm was measured and calculated by the following equation. However, in the case of a low-magnification foam sheet, if the entire surface is not filled with air bubbles, the length of the non-foamed portion having no air bubbles on the surface should be totaled and subtracted from 10 mm of the formula molecule. I do. d = 10 / bubble number

In the present invention, the value measured by this method is 0.005 to 0.5 mm. If it exceeds 0.5 mm, it is difficult to reduce the surface smoothness Rmax to 200 μm or less even if surface treatment with a heat roll is performed.
For example, if an attempt is made to increase the surface smoothness by increasing the temperature of the heat roll, the foam sheet undergoes secondary foaming, and this value increases. This value can be adjusted by a method such as compounding, a mold, a slit, and air-cooling.

The maximum value of the surface smoothness of the foamed sheet measured by a surface shape analyzer (SAS-2010 manufactured by Meishin Koki Co., Ltd.) is defined as Rmax, and this value is defined as 200 μm.
Do the following. The measurement conditions of Rmax are as follows: the reference length in the X-axis direction is 10 mm, the measurement pitch is 5 μm, and the measurement speed is 0.5 m.
It was determined in m / sec. And the same measurement is performed in the Y-axis direction 10
Measured at any five points within the mm width, and the Rm of the five points
ax, and calculates the average value of the surface smoothness Rma of the present application.
x value. As a measuring device of Rmax, a handysurf (manufactured by Tokyo Seimitsu Co., Ltd.) E
-30A or the like can also be used. Although the measurement conditions, the measurable range, and the like are slightly different, the values measured using this Handysurf E-30A were not significantly different from the values measured using the former device.

When the surface smoothness Rmax exceeds 200 μm, it is difficult to control the peel strength. In order to adjust the surface smoothness Rmax, the bubble diameter (currently, the smallest bubble is up to 5 μm), air volume, heat load
By means such as At present, the limit of the foam is about 5 μm. The peel strength between the thermoplastic resin laminated foam sheet and the thermoplastic resin film is 5 to 400.
g / 25 mm width. If it is less than 5 g / 25 mm width, it will peel off during use as a container, while 400 g
If the width exceeds / 25 mm, the film is hardly peeled off, and if it is forcibly peeled off, the film may be broken. When the lid is laminated so as to be peelable, the peel strength is preferably set to 100 g / 25 mm width or more. The peel strength was measured using a sample having a width of 25 mm and a length of 110 mm.
c Corporation Tensilon RTM-5
00 is the average of the values recorded on the chart paper when the ends of the film and foam sheet were pulled apart in the direction of 180 degrees at a speed of 200 mm per minute.

The thermoplastic resin foam sheet of the present invention is obtained by feeding a polystyrene resin, a polyolefin resin, a polyester resin or the like into an extruder, heating and kneading to melt the resin, and adding a blowing agent to the molten resin. It is usually produced by addition. The polystyrene-based resin used in the present invention refers to a polymer having a styrene-based vinyl monomer such as styrene, methyl styrene, and dimethyl styrene as a main constituent unit, and the expanded polystyrene-based sheet used in the present invention is polystyrene. A foamed sheet composed of a homopolymer or a copolymer containing 50% by weight or more of a styrene-based monomer. The monomer copolymerizable with the styrene-based monomer may be acrylic acid, methacrylic acid or these. Esters, acrylonitrile, acrylacid, methacrylonitrile, maleic anhydride and the like. Examples of the polyolefin resin include high-density polyethylene, low-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-carboxylate ester copolymer, ethylene-carboxylate metal salt copolymer, crystalline propylene homopolymer, and crystal. Propylene-ethylene copolymer, crystalline propylene-ethylene-diene terpolymer, and polyethylene terephthalate as a polyester resin.
And polybutylene terephthalate, polybutylene terephthalate elastomer, crystalline polyester and polycyclohexane terephthalate.

The foaming agents include hydrocarbons such as propane, i-butane, n-butane, i-pentane, n-pentane, or mixtures thereof, and N ₂ , CO ₂ , N _2
2 / CO _2, water, water with -OH, -COOH, -CN, -N
_{H 3, -OSO 3 H, -NH} , CO, NH 2, -CON
_{H 2, -COOR, -CHSO 3 H} , -SO 3 H, -CO
A mixture with a compound having a group of ON ₄ and —COONH ₄ . Further, examples of the organic foaming agent include foaming agents such as azodicarboxylic acid amide, dinitropentamethylenetetramine, 4,4'oxybis (benzenesulfonylhydrazide). Further, a combination of sodium bicarbonate and / or bicarbonate with an organic acid such as citric acid and / or a salt of an organic acid can also be used. Also,
Although citrates and the like can be used, these can be coated with a low-molecular olefin, flowing para-tallow oil, or the like. Others are mixtures thereof. The expansion ratio of the thermoplastic resin foam sheet is about 1.5 to 20 times. In producing this foamed sheet, a compounding agent usually used in a resin, for example, a cell regulator,
A pigment or the like may be added. In the present invention, when thermoforming is performed later, the thickness of the foam sheet is 0.3 to 5.0 m.
m is usually used.

On the other hand, the thickness of the thermoplastic resin film laminated on the thermoplastic resin foam sheet is usually 5 to 500 μm. When a single-layer film having a thickness of less than 5 μm is extruded, pinholes and the like are easily generated. When a laminated foamed sheet is manufactured by co-extrusion of a single-layer film having a thickness of less than 5 μm, the film may be broken and a hole may be formed. On the other hand, if the thickness exceeds 500 μm, the economy is poor.
When laminating by heat fusion, the heat capacity of the film is too large and the thermoplastic resin foam sheet is greatly affected by heat,
During molding, it may be separated from the thermoplastic resin foam sheet.

These thermoplastic resin films include:
Linear low-density polyethylene, high-density polyethylene, low-density polyethylene, propylene homopolymer, ethylene-propylene random copolymer, ethylene-propylene block copolymer, ethylene-propylene-butene-terpolymer, ethylene-vinyl acetate copolymer Copolymer, ethylene-unsaturated carboxylic acid ester copolymer (for example, ethylene-methyl methacrylate copolymer), ethylene-unsaturated carboxylic acid metal salt copolymer (for example, ethylene-magnesium acrylate (or zinc)) Copolymer), propylene-vinyl chloride copolymer, propylene-butene copolymer, propylene-maleic anhydride copolymer, propylene-olefin copolymer (propylene-ethylene copolymer, propylene-butene-1 copolymer) polyethylene or Polypropylene Unsaturated carboxylic acids (e.g., maleic anhydride) modified products, ethylene - propylene rubber, atactic polypropylene and the like, polyethylene,
Ethylene-propylene copolymer, propylene-butene-
Films such as one copolymer and a mixture of two or more of these are exemplified. As the crystalline polypropylene-based resin, crystalline propylene homopolymer is preferable, but in addition to the above, mainly crystalline polypropylene such as crystalline propylene-ethylene copolymer and crystalline ethylene-propylene-diene terpolymer are used. Polymers. Further, the resins exemplified as the thermoplastic resin foam such as a polystyrene-based resin and a polyester-based resin can also be appropriately used.

Furthermore, in order to prolong the freshness retention of the contents, it is preferable to laminate a film or a gas barrier film previously mixed with an antibacterial agent such as silver ion, extract from wasabi, etc. on the foamed thermoplastic resin sheet. . Examples of these gas barrier films include ethylene-vinyl acetate copolymer, polyvinyl alcohol, polyvinylidene chloride, polyamide, polyester, polyacrylonitrile, vinylidene chloride-acrylonitrile copolymer, and acrylonitrile-methyl methacrylate. -Butadiene copolymer,
Nylon 6, biaxially stretched nylon, biaxially stretched polyethylene terephthalate, biaxially stretched polypropylene, high-density polyethylene, a film made of ionomer resin (for example, Surin®), or a combination of the above polymers Film, or metal deposition film alone, or
What laminated | stacked these several films is used. It is also possible to laminate an aluminum foil or a thermoplastic resin film laminated with an aluminum foil.

In the present invention, the lamination of the thermoplastic resin foam sheet and the thermoplastic resin film may be performed by laminating with an adhesive, laminating with a heat roll, co-extrusion, or intermediate between the foam sheet and the film. There is a method of laminating under pressure through an adhesive resin film in a molten state extruded from a T-die. As the adhesive that can be used, any of a thermoplastic resin-based adhesive, a thermoplastic elastomer-based adhesive, a pressure-sensitive adhesive, a hot-melt adhesive, a rubber-based adhesive, and the like may be used.
For example, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer and mixtures thereof, styrene block butadiene block copolymer elastomer, styrene butadiene copolymer elastomer, and the like can be used. In the case of thermocompression bonding, the film is heated and pressed from the side opposite to the joining surface by a heat roll. In this case, the surface of the roll to be heated and pressed should be chrome-plated or Teflon-coated.
To prevent adhesion or stickiness with the heated film. In the present invention, it is preferable that the joint surface is heated by a heating device together with the thermocompression bonding by the heat roll.

When a molded article is obtained by molding the foam sheet, a barrier film is often provided inside the molded article, and a lid is sealed on the film. In this case, if the peel strength is less than about 100 g / 25 mm width, the film will peel off with the lid when the lid is opened.
In such a case, if the molded product on which the lid is to be laminated is provided with uneven streaks, knurled, pear-shaped (patterned), or grooved in a ring shape, it is pressed during molding. The peel strength is increased by 20 to 200% only at the contacted portion, and the film does not peel when the lid is opened. Also, if the adhesive layer is foamed or a filler is mixed with the adhesive layer, the adhesive strength is weakened, and the effect of easily increasing the difference in the strength of the adhesive strength when processing such as knurling is performed. is there.

The lamination of the thermoplastic resin foam sheet and the thermoplastic resin film may be performed by a co-extrusion method.
The reason is that it is excellent in stability, workability and economy. From thermoplastic resin laminated foam sheet or its molded product,
As a result of peeling off the thermoplastic resin film and observing the peeling surface of the foam, it is important to control the cell diameter and surface smoothness within a certain range in order to reduce the variation in peel strength by co-extrusion. But it became clear through repeated tests. The value of the peel strength between the thermoplastic resin laminated foam sheet (hereinafter sometimes referred to as the raw fabric) and the molded product differs depending on the molding method and the molded shape, but there is no great difference.
Generally, within 20%, the molded product is larger than the raw material.

In the coextrusion, the size of the bubbles in the minor axis direction on the surface of the thermoplastic resin foam sheet is set to 0.00.
5 to 0.5 mm and surface smoothness Rmax of 5 to 200 μm
In order to control the temperature to m, it is preferable to control the temperature variation in the circumferential direction of the out ring at the tip of the mold within 3.0 ° C. and the variation in the extrusion amount within 3%. The temperature variation in the circumferential direction of the outer ring at the tip of the mold was measured at eight points in the circumferential direction using a surface thermometer, and the difference between the maximum value and the minimum value was determined. In addition, at any time during the extrusion, the weight of the extruded amount is measured every minute for 20 minutes continuously, and the average value and the difference between the maximum value and the minimum value are calculated. Then, the ratio of the difference between the maximum value and the minimum value with respect to the average value was defined as the variation of the extrusion amount.
Then, the temperature variation at the tip of the cylinder of the extruder is reduced to 5.
It is more preferable to keep the temperature within 0 ° C. The temperature variation at the tip of the cylinder of the extruder was measured at six points on the outer circumferential surface of the tip of the cylinder with a surface thermometer, and the difference between the maximum value and the minimum value was obtained. Also, in order to reduce the variation of the extrusion amount,
It is particularly necessary to keep the water content of the raw material resin at 0.1% or less, to cool the surroundings of the extruder hopper-mounting, and to reduce the length of the heating / cooling device of the cylinder and the interval between each heating / cooling device. It is valid.

Immediately after the extrusion, the foam sheet surface is air-cleaned.
However, it is effective to appropriately adjust the temperature and amount of the cooling air. In the co-extrusion method, an adhesive may be interposed between the thermoplastic resin foam sheet and the thermoplastic resin film. In this case, an adhesive that can be used is an ethylene-vinyl acetate copolymer, a methyl methacrylate polymer, or the like. It is. Further, in the present invention, the thermoplastic resin film is made of a thermoplastic resin foam sheet.
May be laminated on both sides of the sheet. Further, the present invention can also be applied to a laminated foam of a foam sheet and a foam sheet of a different resin. For example, a molded article is produced by laminating a foamed polystyrene sheet and a foamed polyethylene sheet via a thermoplastic resin film, and after use, the foamed polyethylene sheet and the foamed polystyrene sheet are separated and recovered. It is. If the film barrier is sufficiently performed, recycled materials (used recovered products), for example, recovered materials such as trays and bowl containers can be used for food containers. The film may be multilayer,
Ethylene-vinyl alcohol or the like may be used by laminating between olefins. Applications of the present application or applications of molded articles include flat panels, decorative materials, building materials, automobile ceiling materials, packaging materials, and the like. After use, the film can be peeled off and the main body side can be reused.

Next, an apparatus for producing a thermoplastic resin laminated foam sheet of the present invention by coextrusion and a method for producing the same will be briefly described with reference to the drawings. In FIG. 1, 21, 22, 2
3 is an extruder, and 1, 2, and 3 are heating cylinders of the extruder. 4, 5, and 6 are screws of an extruder, 7, 8, 9,
Reference numerals 10 and 11 are resin passages. Reference numeral 12 denotes a mold, which includes an inner mold and an outer mold. Reference numeral 13 denotes an annular mold slit, and reference numeral 14 denotes an extruded and foamed thermoplastic resin laminated foam sheet. 20 is a junction. A thermoplastic resin containing a foaming agent flows from the extruder 21, a raw material for an adhesive from the extruder 22, and a raw material for a film from the extruder 23, respectively. Then, in a stacked state, it is extruded into a cylindrical shape from the mold slit 13 through the resin passage of the mold 12.

[0024]

Examples and Comparative Examples Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. Example 1 0.6 parts by weight of a fine talc powder having a diameter of about 5 to 15 μm as a cell regulator in 100 parts by weight of a polystyrene resin having an MI of 1.5 (trade name: DEAKASTYROL HRM-2 Denki Kagaku Kogyo Co., Ltd.) Add the parts
This was put into a screw-type mixing / supplying device mounted on a hopper of an extruder having an inner diameter of 90 mm, mixed uniformly to be supplied to the extruder from the hopper. The cylinder temperature of the extruder was 234 ° C., butane gas (i-butane 65%, n-butane 35%) as a foaming agent was added at 3.6% by weight, and the mixture flowed into the junction at a rate of 67 kg / hr.
On the other hand, as a raw material for a film, a low-density polyethylene resin having an MI of 4.0 (trade name: Mitsubishi Polyethylene LD LK-40)
Mitsubishi Yuka Co., Ltd.) to an extruder with an inner diameter of 65 mm,
And it flowed into the junction. On the other hand, as a raw material for adhesives,
Ethylene-vinyl acetate copolymer (vinyl acetate content 11%
Product name EVA25K Mitsubishi Yuka Co., Ltd.)
It was fed to a 5 mm extruder and flowed into the junction. The combined resin has a diameter of 105 mm and a slit width of 0.5 m
m, and extruded to produce a three-layer laminated foam sheet with an adhesive layer interposed between expanded polystyrene and a low-density polyethylene film. At this time, immediately after coming out of the mold slit, air was applied to the inside and outside of the cylindrically extruded laminated sheet to cool the laminated foamed sheet. The air temperature is 38 ° C, and the air volume is 0.11 Nm ³ /
m ^2, the outer was 0.08Nm ³ / m ^2. Also, it is necessary to minimize bubbles in the peaks and valleys due to the generation of wave fringes on the foam sheet on the side where the film is attached.
This is because peeling variation occurs between the peaks and the valleys.

In order to minimize extrusion fluctuations, the polystyrene resin has a water content of 0.1% by weight or less, cools the periphery of the hopper of the extruder, and cools the cylinder of the cylinder by heating and cooling. The length of the heating and cooling device was shortened to 450 mm from the generally used 600 to 800 mm, and the gap between the heating and cooling devices, which was 40 mm or more, was reduced to 20 m.
m. Due to this, the variation of the extrusion discharge amount conventionally was 3 to 6%, but it was within 2%. The temperature variation at the tip of the cylinder was 2 ° C. The mold is composed of an outer mold and an inner mold. In the resin passage between the outer mold and the inner mold, the thickness of the outer mold is usually 15 mm from the viewpoint of emphasizing cooling.
５０50 mm, but larger. For example, the center of the mold was set to 50 to 150 mm, and the tip of the mold was set to 30 to 60 mm. As a result, the temperature variation in the circumferential direction of the mold was 3 to 5 ° C., but could be 1 to 3 ° C. The thickness of the foam layer of the obtained thermoplastic resin laminated foam sheet was 1.37 mm, the basis weight was 133 g / m ² , and the film thickness was 36 μm. When the film of the laminated foam sheet was peeled off and the surface of the foam layer was observed, the diameter of the bubble in the minor axis direction was 0.326 mm, and the surface smoothness R
The maximum is 113 μm, and the peel strength is 292 g / 2 on average.
With a width of 5 mm (n = 5), the variation in peel strength is 16.2
%Met. This was subjected to secondary foaming to obtain a laminated foamed sheet having a thickness of 3.4 mm. The peel strength between the foam layer and the film was 284 g / 25 mm width (n = 5) on average, and the variation in peel strength was 16.2%. When a gratin container (155L × 125W × 31H) was molded using this sheet, it could be molded favorably. The diameter of the bubble at the bottom of the container in the minor axis direction was 0.303 mm, and the surface smoothness Rmax was At 109 μm, the peel strength was 307 g / 25 mm width (n = 5) on average. Variation in peel strength is 14.5%
Met.

Example 2 To 100 parts by weight of a polystyrene resin having an MI of 1.5 (trade name: Denkastyrol HRM-2 Denki Kagaku Kogyo Co., Ltd.) was added 1 part by weight of talc as a cell regulator, and It is fed to an extruder having an inner diameter of 90 mm, melted at a cylinder temperature of 230 ° C., added with i-butane as a foaming agent, and extruded and foamed from a circular mold at the tip of the extruder to form a polystyrene foam sheet. Manufactured. The discharge rate was 85 kg / hr. And
130 each in a direction substantially perpendicular to the flow direction of the foam sheet.
The foamed sheet is wound in an S-shape into a take-up machine (hereinafter referred to as an S-roll) provided with two rolls heated to a temperature of about 3 m / min. The roll was wound up in a roll. The thickness of this foam sheet is 2.
2 mm, the basis weight was 240 g / m ² , the bubble diameter in the minor axis direction was 0.33 mm, and the surface smoothness Rmax was 75 μm. EVA (VAC 11%) / NA / EV
OH / PS (Sumilite Sumitomo Bakelite Co., Ltd.)
The laminated film of 80 μm is thermocompressed from the outside of the film with a heating roll at 190 ° C., and the speed is 8 m / mi.
n and then cooled about 21 seconds later with a cooling roll at 21 ° C. EVA ethylene vinyl acetate copolymer VAC vinyl acetate content NA polyamide EVOH ethylene vinyl alcohol copolymer PS polystyrene The peel strength between the foamed sheet and the film of the obtained laminated foamed sheet was measured five times. That is, when n = 5, the values are 305 g / 25 mm width, 307 g / 25 mm width, respectively.
331 g / 25 mm width, 332 g / 25 mm width, 325
g / 25 mm width. The average peel strength is 320 g
/ 25 mm width, dispersion of peel strength = (maximum value−minimum value) / average value × 100 = (332-305) / 320 ×
100 = 8.4%. Using a molding machine, a bowl container was formed from the laminated foam sheet at a heater temperature of about 395 ° C. and a heating time of 5.3 seconds. The film was successfully molded without peeling during the molding. Table 1 shows the bowl shape and peel strength.

Comparative Example 1 In Example 2, talc was used in an amount of 0.1 part by weight,
The procedure was performed in the same manner except that the sample was taken at room temperature. Foam sheet
G is 2.1 mm, the basis weight is 245 g / m ² , the bubble diameter in the minor axis direction is 0.51 mm, and the surface smoothness Rmax is 24.
It was 5 μm. When the same film as in Example 2 was fused under the same conditions, the average peel strength was 491 g / 25 mm width. When the film was peeled by hand, the foam sheet caused material destruction. The peel strength was n = 5, and the respective measured values were 385 g / 25 mm width, 438 g / 25 mm width, and 550 g.
g / 25mm width, 535g / 25mm width, 547g / 2
The width was 5 mm. The variation in the peel strength was 33.6%. Using a molding machine, a bowl container was molded from the laminated foam sheet at a heater temperature of about 395 ° C. and a heating time of 5.5 seconds. The dispersion of the peel strength was large, and it was difficult to adjust the peel.

Example 3 Polyethylene terephthalate (PET) (trade name: Teijin Pet Resin TR8580 Teijin Limited) was dried, and then 0.1 part by weight of sodium carbonate and 0.6 part by weight of talc were added. At -290 DEG C., n-butane was added and extruded from a circular mold at the tip of the extruder. And
Using an S-roll heated to 105 ° C., about 4.5 m /
min. The thickness of the foam sheet is 1.45mm,
Basis weight: 262 g / m ² , bubble diameter in the minor axis direction: 0.48 m
m and surface smoothness Rmax were 123 μm. Thickness 5
EVA (VAC 11%, trade name: Mitsubishi Polyethylene-E)
VA25K (Mitsubishi Yuka Co., Ltd.) with a coating of 15 μm and the above foamed sheet were heated at 135 ° C.
Thermocompression bonding from the outside of the film, 3.6m / min
Then, after about 0.5 seconds, the mixture was cooled with a cooling roll at 21 ° C. The average value of the peel strength is 313 g / 25.
mm width (n = 5, each 287 g / 25 mm width, 3
18g / 25mm width, 327g / 25mm width, 332g
/ 25mm width, 301g / 25mm width), variation =
(Maximum value−minimum value) / average value × 100 = 14.4%. The laminated foam sheet was molded in a baking machine at a heater temperature of about 305 ° C. and a heating time of 9.3 seconds. The film was successfully molded without peeling during the molding. As shown in Table 1, the average peel strength was 314 g / 2.
With a width of 5 mm, the film did not peel off.

Comparative Example 2 In Example 3, talc was used in an amount of 0.3 part by weight,
The procedure was performed in the same manner, except that the sample was taken at room temperature with a filter. The thickness of the foam sheet is 1.55 mm, and the basis weight is 267 g /
m ² , bubble diameter in the minor axis direction is 0.53 mm, surface smoothness R
The max was 255 μm. The same film as in Example 3 was thermocompression-bonded to the sheet from the outside of the film by a heat roll heated to 121 ° C., and was fused at a speed of 3.5 m / min. After 5 seconds, the mixture was cooled with a cooling roll at 21 ° C. The average peel strength was 345 g / 25 mm width (n =
5, 270 g / 25 mm width, 365 g / 25 mm width, 3
94g / 25mm width, 331g / 25mm width, 365g
/ 25 mm width). Variation in peel strength is 35.
9%. When the laminated foam sheet was molded by a molding machine at a heater temperature of about 298 ° C. and a heating time of 9.2 seconds, bubbles were generated during the molding. As shown in Table 4, the peel strength of this container was large.

Example 4 As a foam sheet raw material, polypropylene (trade name: Pro-fax PF814, Himont) and a bubble regulator (trade name: DAIBRO-HC No. 2 Dainichi Seika Kogyo Co., Ltd.) 2 parts by weight were fed to an extruder having an inner diameter of 90 mm, i-butane was added at a cylinder temperature of 230 ° C. to 245 ° C., and flowed into the junction at a rate of 66 kg / hr. Polystyrene (PS) (trade name: Denkastyrol HRM-2 Denki Kagaku Kogyo Co., Ltd.) and high impact polystyrene (H
IPS) (butadiene content 6%)
(HI-E-4 Denki Kagaku Kogyo Co., Ltd.) A pigment (yellow master batch) was added to a 1: 1 mixture, and the inner diameter was 6%.
It is fed to a 5 mm extruder, melted at 230 ° C, and
/ Hr (extruded amount) into the junction, and (as a raw material for the adhesive) ethylene-vinyl acetate (VAC 6%
Brand name Suntec-EVA EF-0603 Asahi Kasei Corporation and polyethylene (PE) (brand name Suntech-L)
DF1920 Asahi Kasei Corporation) 1: 1 mixture was supplied to an extruder having an inner diameter of 45 mm, and 9 kg / h at 180 ° C.
The mixture flowed into the junction at a ratio of r, and was co-extruded to obtain a laminated foamed sheet. Also, in order to minimize extrusion fluctuation,
The resin has a water content of 0.1% by weight or less, cools around the hopper mounting of the extruder, and reduces the length of one zone of the heating and cooling device of the cylinder to 600 to 8 which is generally used.
The gap between the heating and cooling devices, which was shortened from 00 mm to 450 mm, and was 40 mm or more, was set within 20 mm. Due to this, the variation of the extrusion discharge amount conventionally was 3 to 6%, but it was within 2%. The temperature variation at the tip of the cylinder was 2 ° C. Also, the mold is composed of an outer mold and an inner mold. In the resin passage between the outer mold and the inner mold, the thickness of the outer mold is 15 to 50 mm from the viewpoint of emphasizing cooling. Enlarge. For example, 50 at the center of the mold
The width was set to about 150 mm, and the width at the tip of the mold was set to 30 to 60 mm. As a result, the temperature variation in the circumferential direction of the mold was 3 to 5 ° C., but could be 1 to 3 ° C. This laminated foam sheet has a thickness of 1.33 mm and a basis weight of 340 g / m ^2.
Met. When the film is peeled off from the laminated foam sheet,
The bubble diameter in the minor axis direction was 0.50 mm, and the surface smoothness Rmax of the foam sheet was 198 μm. Peel strength is 25g
/ 25mm width (n = 5, 22g / 25mm width, 25g /
25mm width, 24g / 25mm width, 28g / 25mm
Width, 26g / 25mm width) and the variation in peel strength is 2
4%. Using a molding machine, the laminated foam sheet was molded into a baking container at a heater temperature of about 380 ° C. and a heating time of 16.5 seconds. Without the film peeling during molding,
Good molding was achieved.

Example 5 In Example 4, the extruder having an inner diameter of 65 mm was stopped, and a PP foam sheet with an adhesive layer was extruded. When the EVA as the adhesive layer was peeled off and the cell diameter and Rmax were measured, the cell diameter in the minor axis direction was 0.50 mm on average, and Rmax
Was 185 μm. The basis weight of the foam sheet is 342 g /
m ² , 1.38 mm thickness and adding an adhesive layer, the basis weight is 38
It became 8 g / m ² . NA /
73μ of EVOH / PS (Sumitomo Bakelite Co., Ltd.)
m barrier film was applied to the bonding surface of the sheet and the film with hot air of 85 ° C., and thermocompression-bonded at 3.2 m / min speed from the outside of the film with a heat roll heated to 195 ° C. . The peel strength of this laminated film is 26 g / 25 m
m width (n = 5 25 g / 25 mm width, 29 g / 25 mm
Width, 28g / 25mm width, 30g / 25mm width, 31g
/ 25 mm width) and the variation was 23.1%. The laminated foam sheet was heated at a heating temperature of 365 ° C. with a molding machine.
A baking container was molded with a heating time of 16.7 seconds. The film was successfully molded without peeling during the molding.

Example 6 A laminated film obtained by laminating a water-absorbing and oil-absorbing nonwoven fabric hot-coated on a 45 μm EMA / PE film was heated to 75 ° C. in hot air at a temperature of 75 ° C. in the same foamed sheet as in Example 2. The film was thermocompressed from the outside of the film at a speed of 6.0 m / min with a heat roll heated to 140 ° C., and set to 21 ° C. after about 1.5 seconds. The film side was cooled by contact with a roll. The non-woven fabric used was a rayon mixed with 20% of PP and about 30 g / m ² . The peel strength was 132 g / 25 mm width (n =
5, 123g / 25mm width, 138g / 25mm width, 1
31g / 25mm width, 142g / 25mm width, 128g
/ 25mm width) and the variation is 19/132 × 100 =
14.4%. EMA ethylene-methyl acrylate copolymer (trade name Yucalon EMA XG-300E methyl acrylate content 13% Mitsubishi Yuka Co., Ltd.) PE polyethylene (trade name polyethylene-LD HE
-60 VAC content 6% (Mitsubishi Yuka Co., Ltd.) This laminated foam sheet was heated at a heat temperature of 355 with a molding machine.
C. and a heating time of 6.5 seconds to form a baking container. The film was successfully molded without peeling during the molding.

Example 7 A used laminated tray of a film containing expanded polystyrene and high impact polystyrene was recovered from the market, washed, then ground, and pelletized by a recovery extruder. The MI of the pellet is 6.7 (JIS-K6870).
Butadiene having a particle size of about 1 to 6 μm as a rubber component was mixed in a salami structure in an amount of 0.1%. 0.3 parts by weight of talc having a particle size of about 1 μm and 0.3 parts by weight of barium stearate were added to the pellets to prepare bubbles. The raw material is supplied to a 90 mm extruder (L / D = 40), melted at a cylinder temperature of 230 ° C., added as a foaming agent in a ratio of normal butane / isobutane = 6/4, brought to a foaming proper temperature, and extruded. The foam was extruded and foamed from a circular mold at the tip of the machine, and immediately after extrusion, the sheet surface was cooled with air of 0.15 Nm ³ / m ² and pulled at 3.1 m / min with a normal temperature S roll. I took it. The thickness of the foam sheet is 1.1 mm and the basis weight is 320.
g / m ² , the bubble diameter in the minor axis direction was 0.23 mm, and the Rmax of the surface was 83 μm. After leaving the sheet for 4 days, an impact-resistant polystyrene resin film having a butadiene rubber content of about 460 μm and containing about 6% was added to the sheet.
A hot air of 77 ° C. was applied to the bonding surface of the sheet and the film, and
7 m / m from the outside of the film with a heat roll heated to 5 ° C.
After thermocompression bonding at a minimum speed, the film was immediately brought into contact with a roll set at 21 ° C. to cool the film side. The results are shown in Table 3. The laminated foamed sheet is heated by a molding machine.
A bowl was formed at a tar temperature of 410 ° C. and a heating time of 6.8 seconds. The film was successfully molded without peeling during the molding.

The results of the above Examples and Comparative Examples are shown in Tables 1, 2, 3 and 4.

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

[Table 3]

[0038]

[Table 4]

[0039]

As described above, according to the present invention, a thermoplastic resin foam sheet having a specific cell diameter and surface smoothness and a thermoplastic resin film are fused together, and are continuously formed by an adhesive or coextrusion. And economical thermoplastic resin laminated foam sheet
Can be manufactured. Further, the obtained thermoplastic resin laminated foam sheet, or a molded article molded from the thermoplastic resin laminated foam sheet has an appropriate peel strength,
Moreover, the dispersion of the peel strength is small. Therefore, the film does not peel off during use as a flat panel, a decorative material, a building material, an automobile ceiling material, a packaging material, a food container, or the like. In addition, even when the film is peeled for recovery and reproduction after being used for various purposes, there is no problem that the film is cut during peeling or that the film cannot be completely or partially peeled. When the punched sheet after forming the food container or the like from the raw material is recycled, there is an effect that the film can be peeled off without any problem. As described above, the thermoplastic resin laminated foam sheet of the present application, or a molded article molded from the thermoplastic resin laminated foam sheet, is a flat panel, a decorative material, a building material, an automobile ceiling material, a packaging material. It can be suitably used as a food container or the like.

[Brief description of the drawings]

FIG. 1 is a thermoplastic resin laminated foam sheet according to the present invention.
Diagram of a co-extrusion machine for manufacturing

[Explanation of symbols]

1,2,3 Heating cylinder of extruder 4,5,6
Extruder screws 7, 8, 9, 10, 11 Resin passage 12 Mold 13 Annular mold slit 14 Extruded and foamed thermoplastic resin laminated foam sheet 20 Confluence 21, 22,
23 Extruder

Claims (7)

(57) [Claims] 1. A foamed thermoplastic resin sheet having a diameter of 0.005 to 0.5 mm in the minor axis direction of bubbles on the surface and a surface smoothness Rmax of 5 to 200 μm, and a thermoplastic resin film. Laminated, the thermoplastic resin foam sheet
And the peel strength of the thermoplastic resin film is 5 to 400.
g / 25mm width , and variation in peel strength is average
A peelable thermoplastic resin laminated foam sheet having a value within 30% of the value . 2. The peelable thermoplastic resin laminated foam sheet according to claim 1, wherein the thermoplastic resin foam sheet and the thermoplastic resin film are laminated via an adhesive. 3. A thermoplastic resin film having a thickness of 5 to 5
2. The peelable thermoplastic resin laminated foam sheet according to claim 1, wherein the thickness is 00 μm. 4. A thermoplastic resin foam sheet having a diameter of 0.005 to 0.5 mm in the minor axis direction of bubbles on the surface and a surface smoothness Rmax of 5 to 200 μm, and a thermoplastic resin film. The thermoplastic resin foam sheet and the thermoplastic resin film are peeled or laminated with an adhesive to have a peel strength of 5 to 400 g / 25 mm width and peel.
A method for producing a peelable thermoplastic resin laminated foam sheet, wherein the variation in strength is within 30% of the average value . 5. A thermoplastic resin foam sheet having a diameter of 0.005 to 0.5 mm in the minor axis direction of bubbles on the surface and a surface smoothness Rmax of 5 to 200 μm, and a thermoplastic resin film. Laminated by co-extrusion, the peel strength between the thermoplastic resin foam sheet and the thermoplastic resin film is set to 5 to 400 g / 25 mm width , and the peel strength
A method for producing a releasable thermoplastic resin laminated foam sheet, characterized in that the roughness is within 30% of the average value . 6. The temperature variation in the circumferential direction of the outer ring surface at the tip of the mold is within 3 ° C., and the variation in the extrusion amount is 3 mm.
%. The method for producing a peelable thermoplastic resin laminated foam sheet according to claim 5, wherein the control is made to be within%. 7. The diameter of bubbles in the minor axis direction on the surface is 0.005 to 0.5 mm, and the surface smoothness Rmax.
Is laminated with a thermoplastic resin film having a thickness of 5 to 200 μm and a thermoplastic resin film, and the peel strength between the thermoplastic resin foam sheet and the thermoplastic resin film is 5 to 4 μm.
00g / 25mm width and peel strength variation
A molded article characterized by being thermoformed from a peelable thermoplastic resin laminated foam sheet having an average value within 30% .