JPH1148419A - Olefin based resin laminated sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an olefin based resin laminated sheet, prominent in draw down property and having rigidity, transparency, resistance to cold as well as resistance to heat upon manufacturing and the like of a vessel or a lid employed for the field of foodstuff packaging material. SOLUTION: An olefin based resin laminated sheet is constituted of surface layers of olefin based resin, having the density of 0.920 g/cm<3> or less and the melt flow rate of 0.3-20 g/10 min, and an intermediate layer, containing 15 wt.% or more of polyolefin resin and having the melt flow rate of 10 g/10 min or less as well as the density of 0.940 g/cm<3> or less while being pinched between the surface layers. In this case, the maximum amount of sagging of the sheet is specified so as to be 20 mm or less when a sheet having the thickness of χ mm of central horizontal part, apart from upper and lower heater surfaces, heated to 450 deg.C, by 15 cm, is heated for the period of time of f(x). Here, f(x) is shown by the formula of f(x)=31.6x+20.5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an olefin resin laminated sheet excellent in thermoformability and rigidity. More specifically, the present invention relates to a laminated sheet of an olefin-based resin having excellent sag retention, rigidity, transparency, cold resistance, and heat resistance, which is superior to conventional ones, in producing containers and lids used in the field of food packaging materials.

[0002]

2. Description of the Related Art Conventionally, propylene-based resin sheets have been used in the production of molded articles such as various containers, cups and trays by secondary molding (vacuum molding, pressure molding, etc.) because of their excellent heat resistance and oil resistance. ing. However, when processing containers by thermoforming such as vacuum forming, the polypropylene resin sheet has sharper melting characteristics than other resins (polystyrene, polyvinyl chloride resin, etc.).
There is a drawback that drawdown property due to heating at the time of preheating is large, and wrinkles, uneven thickness, or holes are easily generated in the molded container. Therefore, as a technique for improving the sagging during thermoforming of the polypropylene sheet, a general method of blending a polypropylene resin with a polyethylene resin (Japanese Patent Application Laid-Open Nos. 52-136247 and 55-108433, and Japanese Patent Publication No. Sho 63-108433). No. 30951), a method of adding bismaleimide to a polypropylene resin (Japanese Unexamined Patent Publication No. 3-5 / 1990).
No. 2493) and a method of using a composition obtained by blending an inorganic filler and a maleic anhydride-modified polyolefin or a silane-modified polyolefin with polypropylene (JP-A-51-69553 and JP-A-52-15542). Have been.

However, in a method of simply blending polyethylene or a method of adding bismaleimide, a sheet width of 90% is required.
When the width is increased to 0 mm or more, the drawdown property becomes remarkably large, and in recent years, a fitting product that is a container with improved hygiene and handling properties is heated more than twice as long as the conventional heating time in order to obtain the shape of the product. There is a limit to the application to wide sheets, such as the drawdown property being further increased. In addition, a mixture of inorganic fillers has a good drawdown property to some extent, but is inferior in transparency and cold resistance.Therefore, a wide sheet excellent in drawdown property while maintaining transparency and cold resistance is required. I was In particular, in recent years, with the increase in frozen foods and microwave-heated foods, fitting containers and deep drawing containers, which are vacuum molded products with little residual distortion, have become widespread, and the productivity of vacuum molding can be improved from container producers. Development of materials for wide sheets of 1 m or more is desired.

[0004]

SUMMARY OF THE INVENTION In view of the above situation, an object of the present invention is to provide containers and lids used in the field of food packaging materials, which are excellent in drawdown properties, and have high rigidity, transparency, and cold resistance. And to provide a heat-resistant olefin-based resin laminated sheet.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies in order to achieve the above-mentioned objects, and as a result, have used a melt flow rate and an olefinic resin having a different density, and in particular, a specific amount of a polyethylene resin in the intermediate layer. By making a multi-layered olefin-based resin laminate sheet, the drawdown properties are significantly improved even when a recycled material is charged, and the rigidity, transparency, cold resistance, and heat resistance are found to be excellent. It has been reached.

That is, the present invention has a density of 0.920 g.
/ Cm ³ or less, melt flow rate is 0.3 to 20 g /
The surface layer of the olefin-based resin for 10 minutes and the intermediate layer of the olefin-based resin containing 15% by weight or more of the polyethylene resin and having a melt flow rate of 10 g / 10 minutes or less and a density of 0.940 g / cm ³ or less are provided. When a シ ー ト mm-thick sheet (30 cm × 30 cm sample test piece) at a central horizontal portion 15 cm away from the upper and lower heater surfaces heated to 450 ° C., which is a laminated sheet sandwiched between layers, is heated for f (x) hours Is an olefin-based resin laminated sheet having a maximum sag of 20 mm or less. The heating time f (x)
The second is calculated from the following equation. f (x) = 31.6χ + 20.5

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. 1. Surface layer The olefin-based resin used for the surface layer of the sheet contains propylene as a main component. Specifically, propylene homopolymer or propylene having a propylene content of 97% by weight or more, ethylene, butene-1, pentene-
Α- such as 1, hexene-1, 4-methyl-pentene-1
A random or block copolymer with an olefin or a mixture thereof, or an ethylene (co) polymer (a homopolymer of ethylene or ethylene and α of 3 to 20, preferably 3 to 12, more preferably 3 to 8 -Copolymer with olefin) having an ethylene content of 50% by weight or more based on the propylene resin, such as an olefin mixture containing 40% by weight or less, especially propylene homopolymer or propylene homopolymer. A mixture of the coalescable and the propylene-α-olefin copolymer or a block copolymer is preferred in terms of rigidity, transparency, heat resistance, and cold resistance.

The olefin resin is JIS-K67
Melt flow rate (hereinafter sometimes referred to as MFR) measured in accordance with No. 58 (230 ° C.-2.16 kg load) is 0.3 to 20 g / 10 min, preferably 0.5 to 20 g / min.
10 g / 10 min, more preferably 1.5 to 10 g / 1
When the MFR is more than 20 g / 10 minutes, the drawdown property is poor. When the MFR is less than 0.3 g / 10 minutes, surging occurs at the time of forming the laminated sheet, and a container with poor thickness deviation and poor transparency occurs. .

The olefin resin is JIS-K67
The density measured according to 58 (23 ° C.) is 0.920 g
/ Cm ³ or less, preferably 0.903 to 0.92
0 g / cm ³ , more preferably 0.905 to 0.915
a g / cm ^3, the density is 0.920 g / cm ³ greater than the transparency and gloss adhesion is poor between the cooling roll failure.

[0010] 2. Intermediate Layer The composition constituting the olefin-based resin layer used for the intermediate layer of the sheet is preferably one in which an ethylene (co) polymer is blended in a propylene (co) polymer at 15% by weight or more. A propylene (co) polymer is a homopolymer of propylene or propylene and ethylene or 4-2 carbon atoms.
Α of 0 (preferably 4 to 12, more preferably 4 to 8)
A block or random copolymer with an olefin, wherein the content of the propylene polymer in the propylene (co) polymer is preferably 60% by weight or more, more preferably 7% by weight or more.
0% by weight or more. Specifically, the propylene (co) polymer used has a propylene content of 99 to 90.
Weight percent of propylene and a random or block copolymer of α-olefins such as ethylene, butene-1, pentene-1, hexene-1, and 4-methyl-pentene-1 or a mixture thereof. Homopolymers, propylene-α-olefin blocks or random copolymers are preferred.

The propylene (co) polymer may be a mixture of two or more of the above, but those having a propylene content of 99 to 90% by weight, preferably 98 to 94% by weight are those having rigidity and heat resistance. From the point of view, and JIS-
MF based on K6758 (230 ° C-2.16 load)
R is 10 g / 10 min or less, preferably 0.5 to 10 g /
10 minutes, more preferably 0.5 to 5 g / 10 minutes is preferred in view of drawdown retention.

The polyethylene resin in the olefin resin composition of the intermediate layer of the sheet may be a homopolymer of ethylene or ethylene and 3 to 20 carbon atoms (preferably 3 to 1 carbon atoms).
2, more preferably a copolymer with α-olefin of 3 to 8), and may be a mixture of two or more kinds. Those having an ethylene content of 50% by weight or more are preferred.

Ethylene homopolymer and ethylene content 7
A copolymer of 0% by weight or more of ethylene and α-olefin is preferable in terms of rigidity and heat resistance, and has a density (JIS K71).
12, method A) is not particularly limited as long as it is 0.970 g / cm ³ or less, but is 0.890 g / cm ^{3 to} 0.930 g.
When a polyethylene resin having a density of / cm ³ is used, a more transparent resin is obtained. The polyethylene resin has an MFR (JIS K7210, condition 4) produced by high-pressure ionic polymerization, gas phase polymerization, or solution polymerization in the presence of a Ziegler-based compound, a metallocene-based compound, or the like as a catalyst of 10 g / 10 minutes or less. , Preferably 0.01 to
10 g / 10 min, more preferably 0.05 to 5.0 g
/ 10 minutes is good. If the MFR is out of the above range, the melt viscosity is too high or too low, so that compatibility with the propylene-based polymer is deteriorated or the fluidity balance with the surface layer is inhibited, thereby causing surging on the sheet. As a result, poor container moldability occurs.

The ratio of the polyethylene resin in the intermediate layer is as follows:
15% by weight or more, preferably 1% by weight, based on the propylene resin
It is a mixture containing 5-90% by weight, more preferably 20-80% by weight, and the MFR (JIS-K67)
58 <230 ° C, 2.16 kg load>)
10 g / 10 min or less, preferably 5 g / 10 min or less, density (JIS K7112, A method) is 0.940 g / c
m ³ or less of what is essential as a constituent of the intermediate layer.

In the above composition, if the polyethylene resin content is less than 15% by weight or the MFR exceeds the above range, the drawdown of the sheet becomes large in the preheating step at the time of vacuum forming, so that wrinkles and holes are generated in the container. Poor moldability occurs, and particularly in the vacuum forming of a wide sheet of 1000 mm or more, the production loss of the container is large. The lower limit of the MFR is not particularly limited as long as the sheet is formed by a sheet forming machine, even if it has substantially no fluidity at the time of MFR measurement. The output decreases and the motor load increases, resulting in lower productivity.
On the other hand, when the density exceeds the above range, transparency and impact resistance are poor.

In addition, each component constituting the surface layer or the intermediate layer of the sheet may include components other than the above components, for example, an antioxidant, an ultraviolet absorber, an antistatic agent, a lubricant, a dispersant, a clarifying agent, a coloring agent, Corrosion inhibitors and the like may be added or applied as appropriate according to the purpose.

The thickness composition of the olefin resin laminated sheet comprising the surface layer and the intermediate layer is such that the thickness ratio of the surface layer is 2% or more of the laminated sheet, preferably 5 to 80%, more preferably 5 to 60%. is there. If it is less than this range, there is no effect of improving the draw-down property of the sheet, and furthermore, the processing temperature range during vacuum forming is narrow, and poor moldability of the container occurs, which is not preferable. The overall thickness of the sheet is not particularly limited as long as the container can be molded at the above layer composition ratio, but is preferably 3 mm or less for general food containers.

The method for producing the laminated resin sheet is a polishing method using a mirror roll, an air knife method (including roll rolling), a metal mirror belt method (including a single or twin belt), or pressing with a metal mirror belt after quenching. The method is not particularly limited as long as it is manufactured by a co-extrusion method such as a T-die method, an inflation method, a calendar roll method, or a lamination method in which a surface layer is fused by a single-layer method or bonded by an adhesive. The co-extrusion method is preferable because productivity and a layer structure can be easily adjusted.

The method for producing a thermoformed product of the olefin-based resin laminated sheet of the present invention includes an indirect heating method (vacuum forming method, pressure forming method, solid-state pressure forming method), solid-state press forming, stamping forming, or the above-mentioned method. There is no particular limitation as long as it is a container forming method based on a combination of forming methods and the like.

The surface temperature of the olefin resin laminated sheet at the time of the above molding is 130 ° C. or higher, preferably 150 ° C.
To 130 ° C, more preferably 150 to 250 ° C. If the temperature is lower than 130 ° C, the melting property of the olefin-based resin laminated sheet is incomplete, so that the moldability of the container is poor and the distortion remains in the container. Then, the container is deformed when reheated in a microwave oven or the like. On the other hand, when the temperature exceeds 350 ° C., the laminated sheet is deteriorated by heat, and the drawdown becomes severe, and wrinkles and holes occur in the container.

With respect to the surface temperature of the olefin-based resin laminated sheet, the calorific value per cross-sectional area decreases as the thickness (χmm) increases, so that the heating temperature at a constant temperature varies the obtained temperature and the sag amount. Accordingly, the heating time f at which a constant amount of sag of the laminated sheets having different thicknesses can be obtained.
(X) can be represented by the following equation. f (x) = 31.6χ + 20.5 f (x): heating time (sec), χ: thickness of olefin-based resin laminated sheet (mm) In the present invention, 15 cm away from upper and lower heater surfaces heated to 450 ° C. It is essential that the maximum amount of sag when the χmm-thick sheet (sample test piece of 30 cm × 30 cm) in the center horizontal portion is heated for f (x) hours is 20 mm or less.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments. Example 1 95% by weight of a propylene homopolymer having an MFR of 0.5 g / 10 min and a density of 0.905 g / cm ³ (Nippon Polychem Co., Ltd.)
Manufactured by: Novatec PP EA9 (trade name), melting point 171 ° C
<Hereinafter referred to as HPP-1>) and 5% by weight of ethylene-α-olefin copolymer (manufactured by Nippon Polychem Co., Ltd .: Novatec LL SF240 (trade name), melting point 126 ° C.
100-1 parts by weight of a mixture of DBS (1,3, -2,4-di (P-ethylbenzylidene) sorbitol (trade name: Gelol MD, manufactured by Shin Nippon Rika Co., Ltd.) as a nucleating agent. ) 50 m diameter with 0.2 parts by weight
On the other hand, from an extruder having an mφ, an ethylene homopolymer having an MFR of 0.3 g / 10 min and a density of 0.956 g / cm ³ (Nippon Polychem Co., Ltd .: Novatec HD HB331R (trade name)) 135 ° C <HP
E-1>) was added at a weight of 50%.
Each extruder was extruded from an extruder having a diameter of mmφ and melt-extruded at a resin temperature of 240 ° C. into a sheet having a width of 400 mm at a resin temperature of 240 ° C. from a T-die of a co-extruder equipped with a feed block having two types and three layers. Polymer +
The mixture was melt-extruded so as to have a layer structure of ethylene homopolymer (40 wt%) / propylene homopolymer. Next, the molten sheet was guided to a cooling roll (roll temperature: upper 50 ° C., middle 70 ° C., lower 50 ° C.) of the polishing method to be cooled and solidified, and a propylene homopolymer / propylene weight having a thickness of 0.5 mm and a width of 350 mm was obtained. Merged + ethylene homopolymer (40 wt%) / propylene homopolymer (100/30
(0/100 μm) to produce two and three layers of olefin-based resin laminated sheets. The obtained olefin-based resin laminated sheet was subjected to bending elasticity and AS according to JIS-K6758.
DuPont impact strength was measured according to TM-D2794. Table 1 shows the results.

The laminated sheet is sandwiched between two iron frames (33 mm × 33 mm × 2 mm) each having a hole of 30 cm square at the center, and is set horizontally in a heat insulating box. Next, upper and lower heaters heated to 450 ° C. (the upper and lower heaters heat the laminated sheet from a position 15 cm away from the installed sheet surface) so that the laminated sheet sandwiched in the iron frame can be uniformly heated. To slide.
The sheet in the iron frame once hangs down in the direction of the lower surface heater by heating, and thereafter, when the temperature is uniformly increased in the thickness direction of the sheet, the laminated sheet becomes horizontal again, and the laminated sheet is further heated by the upper and lower surface heaters. Hangs down due to its own weight. The sagging behavior of the laminated sheet described above was measured by applying a laser beam placed below the lower surface heater to the surface of the laminated sheet and measuring the sagging amount at 1 second intervals, and the sagging amount when heating for 35 seconds from the start of heating and the amount thereof. The surface temperature at that time was measured. Table 1 shows the results. Depending on the heating time after 35 seconds, the smaller the amount of sagging or the sagging gradient (the amount of sagging per second when heated for 35 seconds) of the laminated sheet, and the heating until the amount of sagging of the above method reaches 20 mm. The longer the time f (x), the better the drawdown property of the sheet.

Comparative Example 1 HPE-1 was added to 75% by weight of a resin containing a nucleating agent of HPP-1.
The mixture containing 5% by weight was melt-extruded into a sheet having a resin temperature of 240 ° C. and a width of 400 mm from an extrusion type sheet molding machine having a diameter of 50 mmφ. Then, the molten sheet is cooled by a polishing roll (roll temperature: upper 50 ° C., medium 70).
℃, lower 50 ℃), solidify by cooling, thickness 0.5m
m, propylene homopolymer having a width of 350 mm (75 wt.
%) + Ethylene homopolymer (25 wt%) to produce an olefin resin sheet. The obtained olefin-based resin sheet was evaluated for flexural elasticity, DuPont impact strength, or sagging properties in the same manner as in Example 1, and the results are shown in Table 1.

Examples 2 to 6 and Comparative Examples 2 to 7 The thickness of the surface layer and the intermediate layer of the laminated sheet is changed by using the following resin, and the grade of the ethylene polymer added to the intermediate layer is changed. Table 1 shows the mixing ratio and talc
The physical properties and the amount of sagging of the laminated sheet were evaluated in the same manner as in Example 1 except that the laminated sheet mixed at the ratio described in Table 1 was obtained. The results are shown in Table 1.

HPP-1: MFR = 0.5 g / 10 min,
Density = 0.904 g / cm ³ (manufactured by Nippon Polychem Co., Ltd.)
Novatec PP EA9 (trade name) Melting point 171 ° C) HPP-2: MFR = 2.3 g / 10 min, density = 0.9
04g / cm ³ (Novatech P manufactured by Nippon Polychem Co., Ltd.)
BFL-1CK: MFR = 0.5 g / 10 min, density = 0.9
05g / cm ³ (Novatech P manufactured by Nippon Polychem Co., Ltd.)
BEC-2: MFR = 1.4 g / 10 min, density = 0.9
04g / cm ³ (Novatech P manufactured by Nippon Polychem Co., Ltd.)
PEG7 (trade name) melting point: 168 ° C) HPE-1: MFR = 0.3 g / 10 min, density = 0.9
53g / cm ³ (Novatech H manufactured by Nippon Polychem Co., Ltd.)
DHB331R (trade name), melting point 135 ° C) HPE-2: MFR = 0.05g / 10min, density = 0.
945 g / cm ³ (Novatec HD HB21OR (trade name), melting point 135 ° C., manufactured by Nippon Polychem Co., Ltd.) LPE-1: MFR = 0.3 g / 10 min, density = 0.9
23g / cm ³ (Novectech L manufactured by Nippon Polychem Co., Ltd.)
D LF122 (trade name, melting point: 103 ° C.) LLPE-1: MFR = 2.0 g / 10 min, density = 0.
920 g / cm ³ (Novectec LL SF240 (trade name), melting point 126 ° C., manufactured by Nippon Polychem Co., Ltd.) Rubber: MFR = 3.6 / 10 minutes, density = 0.890 g /
cm ³ (Tuffmer A-40 manufactured by Mitsui Petrochemical Industries, Ltd.)
85 <trade name>) Talc: manufactured by Fuji Talc Co., Ltd. Particle size 5um

Example 7 0.2 parts by weight of DBS as a nucleating agent was added to 100 parts by weight of a mixture of 95% by weight of HPP-2 and 5% by weight of LLPE-1 from an extruder having a diameter of 40 mm. , HP
A mixture of P-1 nucleating agent-containing resin and HPE-1 in an amount of 40% by weight was extruded from an extruder having a diameter of 90 mmφ.
From a T-die of a co-extruder equipped with a feed block having two types and three layers, a resin extrusion at a resin temperature of 240 ° C. and a width of 1100 mm is carried out, and propylene homopolymer / propylene homopolymer + ethylene homopolymer (40 wt% ) / Melt extruded so as to have a layer structure of propylene homopolymer. Next, the molten sheet is guided to a cooling roll (roll temperature: upper 60 ° C., middle 80 ° C., lower 60 ° C.) of the polishing method to be cooled and solidified, and a propylene homopolymer / propylene homopolymer having a thickness of 0.5 mm and a width of 1040 mm. Merged + ethylene homopolymer (40 wt%) / propylene homopolymer 1
(00/300/100 μm) to produce a propylene-based resin laminated sheet of two types and three layers.

The obtained olefin-based resin laminated sheet is
Heater temperature of vacuum molding machine (name: FLS 415) manufactured by Asano Research Laboratory: set 325 ° C (lower heater) to 470 ° C
(Upper heater), cycle: drawdown property of olefin-based resin laminated sheet when heated for 5.0 seconds and length: 1
8 cm, width: 25 cm, depth: 3 cm
Table 2 shows the results of visually observing the appearance of the molded sample (take five samples) and the evaluation results of cold resistance and heat resistance.

Comparative Example 8 HPE-1 was added to 75% by weight of a resin containing a nucleating agent of HPP-1.
The mixture containing 5% by weight was melt-extruded from an extrusion-type sheet molding machine having a diameter of 90 mmφ into a sheet having a resin temperature of 240 ° C. and a width of 11,000 mm. Next, the molten sheet was guided to a cooling roll (roll temperature: upper 60 ° C., middle 80 ° C., lower 60 ° C.) of a polishing method to be cooled and solidified to have a thickness of 0.5.
propylene homopolymer (75w
t%) + ethylene homopolymer (25 wt%) layer to produce an olefin-based resin sheet. The obtained olefin-based resin sheet was evaluated for drawdown properties, container moldability, cold resistance, and heat resistance using a vacuum forming machine in the same manner as in Example 7, and the results are shown in Table 2.

Examples 8 to 9, Comparative Examples 9 to 10 Except for using the resin and regenerated material of Example 2 for the surface layer and the intermediate layer, the lamination of the olefin resin was carried out under the processing conditions of the coextrusion apparatus of Example 7. The sheet was obtained, and the results of evaluation of drawdown properties, container moldability, cold resistance, and heat resistance by a vacuum forming machine are shown in Table 2.

The transparency and drawdown properties of the olefin-based resin laminated sheet, or the moldability, cold resistance and heat resistance of the container by a vacuum forming machine were evaluated by the following methods. (1) Transparency One 500-yen coin is placed at the bottom of a container having a depth of 1 cm, and the edge of the container is covered with the olefin-based resin laminated sheet obtained in the example. The results of macroscopic observation of the coins were judged as ◎, △, Δ, and × in the following range. Evaluation criteria Evaluation The character of the 500 yen coin is clearly understood. ◎ 500 yen coin can be confirmed. ○ The 500 yen coin appears to be slightly hazy. △ 500 yen coin cannot be confirmed. ×

(2) Drawdown property at the time of container molding The obtained olefin-based resin laminated sheet is heated to a temperature of 325 ° C. (lower heater) to 470 ° C. with a vacuum molding machine (name: FLS 415) manufactured by Asano Laboratories. A value obtained by measuring the amount of drawdown of the molten laminated sheet when heated at 5.0 ° C. (upper heater) for 5.0 seconds on a scale was defined as the amount of dripping.

(3) Formability of Container The obtained propylene-based resin laminated sheet is converted into a vacuum forming machine (name:
FLS 415) heater temperature: setting 325 ° C (lower heater) to 470 ° C (upper heater), cycle: 5.0
Heat molding in seconds, length: 18cm, width: 25cm, depth:
When a 3 cm container (35 samples) was obtained, the external appearance of the container was visually observed. Evaluation Criteria Results The moldability was good in all 35 containers, and no alteration was observed in the containers. ○ Wrinkles remain in some of the 35 containers or the containers have flesh. △ The container is frequently wrinkled or pitted, resulting in severe container flaking. ×

(4) Cold resistance A container obtained by a vacuum forming machine is filled with 250 g of rice,
After leaving the filled container wrapped and sealed with a stretch film (Yukarap) at −20 ° C. for 24 hours, it was dropped from the height of 1 m to the bottom surface 10 times, and the change in appearance was judged as 〜 to × in the following range. Evaluation criteria Result The container has no cracks or cracks, is durable and does not change. ○ Cracks and cracks occurred in a part of the container due to 4 to 9 drops. △ Cracks and cracks occurred in the container after 1-3 drops. ×

(5) Heat resistance The container obtained by the vacuum forming machine is heated to a room atmosphere temperature of 130.
After heating and leaving for 3 minutes in an oven (Permanent oven made by Komatsu Machinery) set at ° C., the container was taken out of the oven, and the value obtained by measuring the shrinkage due to the dimensional change of the container was judged to be ○ to × in the following range. Evaluation criteria Result The shrinkage of the container is within 0 to 1.5%, and no change is observed in the appearance. ○ The shrinkage of the container is within 1.5 to 3%, and the appearance is slightly deformed. △ The shrinkage of the container is 3% or more, and the container is deformed. ×

[0036]

[Table 1]

[0037]

[Table 2]

[0038]

According to the present invention, a recycled material is obtained by using an olefin-based resin having different MFR and density, and in particular, mixing a specific amount of a polyethylene resin in the intermediate layer to form a multilayered olefin-based resin laminated sheet. , A drawdown resistance is remarkably improved, and a laminated sheet capable of increasing productivity of a container having transparency, rigidity, cold resistance, or heat resistance can be provided.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Osamu Akaike 1 Tohocho, Yokkaichi-shi, Mie Mitsubishi Chemical Corporation Basic Technology Research Institute (72) Inventor Asami Hirashima 1 Tohocho, Yokkaichi-shi, Mie Mitsubishi Chemical Corp. Inside the Basic Technology Research Institute

Claims (2)

[Claims] 1. An olefin resin surface layer having a density of 0.920 g / cm ³ or less and a melt flow rate of 0.3 to 20 g / 10 min, a polyethylene resin of 15% by weight or more, and a melt flow rate of Is a laminated sheet in which an intermediate layer of an olefin resin having a density of 0.940 g / cm ³ or less is sandwiched between surface layers, and 15 cm from the upper and lower heater surfaces heated to 450 ° C.
Χmm thick sheet (30cm × 3
An olefin-based resin laminated sheet having a maximum sag of 20 mm or less when a 0 cm sample test piece) is heated for f (x) hours. The heating time f (x) seconds is calculated from the following equation. f (x) = 31.6χ + 20.5 2. The olefin resin laminated sheet according to claim 1, wherein the thickness ratio of the surface layer in all the layers is 2% or more.