JP2001225427A - Thermoforming laminated sheet and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoforming laminated sheet excellent in fabricability, that is, thermoforming properties such as vacuum forming properties, hot plate moldability, press moldability or air pressure moldability and heat sealability and having transparency, flexibility, heat resistance, pinhole resistance, heat sealability, ESCR resistance, steam impermeability and aroma retention, and a method of manufacturing the same. SOLUTION: The thermoforming laminated sheet has a first layer comprising (i) a resin material based on high density polyethylene with a density of 0.93 g/cm3 or more, a second layer comprising (ii) a resin material based on a high pressure radical processed ethylenic polymer and a third layer comprising (iii) a resin material based on linear low density polyethylene with a density of 0.94 g/cm3 or less and is manufactured by a multilayer inflation method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated sheet for thermoforming mainly composed of a polyethylene resin, and has a secondary workability.
In other words, it is excellent in thermoformability and heat sealability such as vacuum moldability, hot plate moldability, press moldability, and air pressure moldability, and further has transparency, flexibility, heat resistance, pinhole resistance, and ESC resistance.
Containers and packaging materials for foods, beverages, detergents, pharmaceuticals, medical infusions, cosmetics, bath agents, etc., which have excellent R properties, water vapor resistance, fragrance retention, low odor, hygiene, etc., and are recyclable. TECHNICAL FIELD The present invention relates to a thermoforming laminated sheet applied to a method for producing the same.

[0002]

2. Description of the Related Art In general, inexpensive and versatile polyethylene has been used for containers and packaging materials such as containers and packaging materials for foods, beverages, detergents, medicines, medical infusions, cosmetics, bath salts, and the like. And single-layer films and laminated sheets of polyolefin resins such as polypropylene.

[0003] Such a single-layer film, a laminated sheet and the like are required to be easily heat-sealed and easily obtained in a container form. Also, such a single-layer film,
The container obtained from the laminated sheet etc. has transparency for confirming the contents and confirming whether or not foreign matter is mixed therein; flexibility for filling and packing the contents; filling at high temperature, boiling treatment and retort sterilization. It is required to have heat resistance for preventing the occurrence of pinholes due to vibration of the contents during transportation of products, and to have excellent ESCR resistance (environmental stress cracking resistance). .

In recent years, containers and packaging materials are required to be easily recyclable and easily collected, and are required to satisfy the above-mentioned various performances and the recyclability and collection properties.

As a laminated sheet satisfying such performance, for example, Japanese Patent Application Laid-Open No. 4-266759 and Japanese Patent Application Laid-Open
JP-A-171039, JP-A-6-246886 and JP-A-8-309939 disclose low-density linear polyethylene, high-density polyethylene, high-pressure low-density polyethylene, or a mixture thereof in two or three layers. Laminated laminated sheets have been proposed.

However, these laminated sheets are insufficient in transparency, heat sealing strength, and pinhole resistance, and have not sufficiently satisfied the above-mentioned various properties required for containers and packaging materials. Also, these laminated sheets have poor drawdown resistance, and therefore, when subjected to thermoforming (vacuum forming, hot plate forming, press forming, pressure forming, etc.),
Defects such as wrinkles, uneven thickness and perforation are likely to occur on molded products,
It was difficult to manufacture containers by thermoforming.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide excellent secondary workability, that is, excellent heat moldability and heat sealability such as vacuum moldability, hot plate moldability, press moldability, and air pressure moldability. Another object of the present invention is to provide a thermoforming laminated sheet having transparency, flexibility, heat resistance, pinhole resistance, ESCR resistance, water vapor transmission resistance, and fragrance retention, and a method for producing the same. An object of the present invention is to provide a laminated sheet for thermoforming which has an odor, has hygiene properties and is excellent in recyclability, and a method for producing the same.

[0008]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the conventional problems, and as a result, have achieved the above object by the thermoforming laminated sheet using a specific resin combination, and reached the present invention. did. That is, the laminated sheet for thermoforming of the present invention comprises a first layer made of a resin material (i) mainly composed of high-density polyethylene having a density of 0.93 g / cm ³ or more, and a high-pressure radical process ethylene-based polymer. A second layer made of a resin material (ii) as a main component, and a density of 0.94 g / cm.
^{And a third} layer made of a resin material (iii) containing ³ or less linear low-density polyethylene as a main component.

The laminated sheet for thermoforming of the present invention is desirably laminated in the order of the first layer, the second layer, and the third layer. Moreover, the thickness of the laminated sheet for thermoforming is 50 μm or more.
5 mm, and the thickness of the first layer is 10 μm to 1 mm,
The thickness of each of the second and third layers is 20 μm to 2 m, respectively.
m is desirable. Further, it is desirable that the laminated sheet for thermoforming of the present invention further has a barrier layer (IV). Further, any one of the I-th layer, the II-th layer and the III-th layer is formed of a resin material (i), a resin material (ii) and a resin material (iii) obtained by recycling the thermoforming laminated sheet. It is preferable that a recycled resin layer (V) formed of a blend resin or made of the blend resin is further provided.

It is desirable that the linear low density polyethylene satisfies the following requirements (a) to (d). (A) a density of 0.86 to 0.94 g / cm ³ , (b) a melt flow rate of 0.01 to 50 g / 10
(C) a molecular weight distribution (Mw / Mn) of 1.5 to 4.5; (d) a total of 25 obtained from an integrated elution curve of an elution temperature-elution amount curve by a continuous heating elution fractionation method (TREF). The difference T ₇₅ -T ₂₅ and the density d between the temperature T _{25 at} which% elutes and the temperature T _{75 at} which 75% of the total elutes satisfy the following (Equation 1): (Equation 1) T ₇₅ -T ₂₅ ≦ -670 × d + 644

The linear low-density polyethylene further satisfies the following requirements (e) and (f) (A1):
Desirably, it is a linear low density polyethylene. (E) orthodichlorobenzene (ODC) at 25 ° C.
B) The soluble content X (% by weight), the density d and the melt flow rate (MFR) satisfy the relationship of the following (Formula 2) and (Formula 3) (Formula 2) d−0.008 log MFR ≧ 0.93 X <2.0 (Equation 3) d−0.008 log MFR <0.93 X <9.8 × 10 ³ × (0.9300−d + 0.008)
(logMFR) ² +2.0 (f) Presence of multiple peaks in elution temperature-elution amount curve by continuous heating elution fractionation method (TREF)

Further, the linear low-density polyethylene further satisfies the following requirements (g) and (h) (A2)
Desirably, it is a linear low density polyethylene. (G) elution temperature by continuous Atsushi Nobori elution fractionation (TREF) - it is one peak of elution curve and the T ₇₅ -T ₂₅ and density d is, satisfy the relation of the following (Equation 4) ( (H) T ₇₅ −T ₂₅ ≧ −300 × d + 285 (h) One or two melting point peaks, and the highest melting point T _ml and density d satisfy the relationship of the following (Formula 5) ( Formula 5) T _ml ≧ 150 × d−17 Further, it is desirable that the (A2) linear low-density polyethylene further satisfies the following requirement (i). (I) Melt tension (MT) and melt flow rate (MFR) satisfy the following (Equation 6) (Equation 6) logMT ≦ −0.572 × logMFR + 0.3

The linear low-density polyethylene is preferably produced in the presence of a catalyst containing at least an organic cyclic compound having a conjugated double bond and a transition metal compound belonging to Group IV of the periodic table. . In addition, the resin material (ii
It is desirable that the additive blended in i) is an additive that does not substantially migrate to the contacted object, or that the additive is not blended in the resin material (iii). The halogen concentration of the resin material (iii) is desirably 10 ppm or less.

Further, the method for producing a laminated sheet for thermoforming of the present invention is characterized in that the laminated sheet for thermoforming is produced by multilayer inflation molding. In the method for producing a laminated sheet for thermoforming of the present invention, at least the resin material (i), the resin material (ii), and the resin material (ii)
The innermost layer of the hollow tube obtained by multilayer inflation molding of i) is made of the resin material (i).
It is desirable to form a layer. In the method for producing a laminated sheet for thermoforming of the present invention, a hollow tube obtained by multilayer inflation molding of at least the resin material (i), the resin material (ii), and the resin material (iii) is sandwiched. It is desirable that the laminated sheet for thermoforming has five or more layers.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The resin material (i) mainly composed of high-density polyethylene (hereinafter, referred to as HDPE) for forming the I-th layer is a resin mainly composed of HDPE and blended with another polyethylene resin as required. As HDPE in the present invention,
Various materials having a density of 0.93 g / cm ³ or more can be used. Specifically, a homopolymer composed of only ethylene, a copolymer composed of ethylene and another monomer (for example, an α-olefin such as propylene, 1-butene, and 1-hexene), or a copolymer composed of ethylene and 2
Examples include a multi-component copolymer composed of at least one kind of monomer.

When the density of HDPE is less than 0.93 g / cm ³ , the resulting sheet loses its stiffness (elastic modulus), barrier properties (water vapor permeability, fragrance retention, moisture resistance), heat resistance, and the like. It is. The melt flow rate (hereinafter referred to as MFR) of HDPE is preferably 0.01 to 50 g / 10.
Min, more preferably from 0.05 to 30 g / min, even more preferably from 0.1 to 10 g / min. MFR (19
(0 ° C.) is less than 0.01 g / 10 minutes, there is a problem in workability, and if it exceeds 50 g / 10 minutes, the strength of the sheet tends to decrease.

The HD in the resin material (i) forming the first layer
The mixing ratio of PE is 50 to 100% by weight, preferably 70 to 100% by weight. HDPE ratio is 50
When the amount is less than the weight percentage, the moisture-proofing property, the water vapor-permeation resistance, and the fragrance retention of the heat shaping laminated sheet are reduced.

The other polyethylene resin used for the resin material (i) for forming the layer I is not particularly limited, but may be a linear low-density resin having a density of 0.86 to 0.94 g / cm ³ as described below. Examples thereof include polyethylene (hereinafter, referred to as LLDPE), and a high-pressure radical method ethylene-based polymer.

The MFR of LLDPE is generally 0.01 to
50 g / 10 min, preferably 0.5 to 30 g /
Min, more preferably 0.5 to 10 g / 10 min. M
If the FR is less than 0.01 g / 10 minutes, a decrease in fluidity (formability of the sheet due to inflation) is observed,
If it exceeds 50 g / 10 minutes, a decrease in strength and the like is observed.

The proportion of the other polyethylene resin in the resin material (i) is less than 50% by weight, preferably 5% by weight.
３０30% by weight. If the proportion of the other polyethylene resin exceeds 50% by weight, the moisture-proof property of the laminated sheet for thermoforming is reduced.

The resin material (ii) containing a high-pressure radical polymerization ethylene polymer as a main component and forming the second layer is a high-pressure radical polymerization ethylene polymer as a main component, and if necessary, other polyethylene. It is a mixture of a base resin.
High pressure radical polymerization method As the ethylene polymer, low density polyethylene (LDPE) by high pressure radical polymerization method,
Ethylene vinyl ester copolymer, ethylene and α, β
-A copolymer with an unsaturated carboxylic acid or a derivative thereof, and the like.

M of the above low density polyethylene (LDPE)
FR is 0.01 to 50 g / 10 min, preferably 0.0 to 50 g / 10 min.
5 to 30 g / 10 min, more preferably 0.1 to 10 g
/ 10 minutes. Within this range, the melt tension is in an appropriate range, and the moldability is improved. When the MFR exceeds 20 g / 10 minutes, the strength of the sheet becomes insufficient. The density of LDPE is 0.9
1 to 0.94 g / cm ³ , more preferably 0.912
０．９0.935 g / cm ³ . Within this range, the melt tension is in an appropriate range, and the moldability is improved. LDPE melt tension is 1.5 ~
25 g, preferably 3 to 20 g, more preferably 3 to
15 g. Also, the molecular weight distribution Mw / Mn of LDPE
Is from 3.0 to 12, preferably from 4.0 to 8.0.

The above-mentioned ethylene / vinyl ester copolymer refers to ethylene-based vinyl propionate, vinyl acetate, vinyl caproate, vinyl caprylate, vinyl laurate, vinyl stearate produced by a high-pressure radical polymerization method. And a copolymer with a vinyl ester monomer such as vinyl trifluoroacetate. Among them, particularly preferred is vinyl acetate. Also, 50 to 99.5% by weight of ethylene, 0.5 to 50% by weight of vinyl ester, and 0
A copolymer consisting of 49.5% by weight is preferred. In particular,
The content of vinyl ester is in the range of 3 to 30% by weight, preferably 5 to 25% by weight. The MFR of the ethylene / vinyl ester copolymer is in the range of 0.01 to 50 g / 10 minutes, preferably 0.05 to 30 g / 10 minutes, and more preferably 0.1 to 10 g / 10 minutes.

The copolymer of ethylene and an α, β-unsaturated carboxylic acid or a derivative thereof includes ethylene
(Meth) acrylic acid or its alkyl ester copolymer is mentioned, and as these comonomers, acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, methacrylic acid Propyl, isopropyl acrylate, isopropyl methacrylate, n-acrylate
Butyl, n-butyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, lauryl acrylate, lauryl methacrylate, stearyl acrylate,
Stearyl methacrylate, glycidyl acrylate, glycidyl methacrylate and the like can be mentioned. Of these, particularly preferred are alkyl esters of (meth) acrylic acid such as methyl and ethyl. In particular, the content of the (meth) acrylate is 3 to
It is in the range of 30% by weight, preferably 5 to 25% by weight.
The MFR of a copolymer of ethylene and an α, β-unsaturated carboxylic acid or a derivative thereof has a MFR of 0.01 to 50 g / 10 min, preferably 0.05 to 30 g / 10 min, and more preferably 0.1 to 10 g / min. 10 minutes.

The second layer is a layer containing an ethylene polymer as a main component by a high-pressure radical polymerization method, and may contain up to 50% by weight of HDPE and LLDPE described later as other polyethylene resins. When blending another polyethylene resin, it is desirable to blend LLDPE up to 40% by weight, more preferably up to 30% by weight.

The resin material (iii) containing linear low-density polyethylene as a main component and forming the layer III is a resin material containing linear low-density polyethylene as a main component and optionally blending another polyethylene resin. It is.

Linear low density polyethylene (LLDPE)
Is a copolymer having a density of 0.94 g / cm ³ or less obtained by copolymerizing ethylene and α-olefin, and ethylene and α-olefin having 3 to 20 carbon atoms, preferably 3 to 12 carbon atoms. It is a copolymer with olefin. As the α-olefin having 3 to 20 carbon atoms, propylene, 1-
Butene, 4-methyl-1-pentene, 1-pentene, 1
-Hexene, 1-octene and the like are used. (A) L
The structural unit derived from the α-olefin having 3 to 20 carbon atoms in LDPE is 1 to 7 mol%, preferably 1 to 7 mol%.
It is 5 mol%, more preferably 2-3 mol%. When the structural unit derived from an α-olefin having 3 to 20 carbon atoms is 7
If it exceeds mol%, the impact resistance, creep resistance, and heat seal strength decrease, and if it is less than 1 mol%, transparency decreases. The linear low-density polyethylene in the present invention is not particularly limited as long as it is as described above, but specific (A) linear low-density polyethylene satisfying the following requirements (a) to (d) is particularly preferable.

The (A) density of the linear low density polyethylene (A) in the present invention is 0.86 to 0.94 g / cm ³ ,
Preferably, it is in the range of 0.89 to 0.94 g / cm ³ , more preferably 0.90 to 0.93 g / cm ³ .
If the density is less than 0.86 g / cm ³ , rigidity (lumbar strength) and heat resistance may be reduced. On the other hand, if the density exceeds 0.94 g / cm ³ , the tear strength, impact resistance and the like may be insufficient.

The (B) MFR of the linear low density polyethylene (A) in the present invention is 0.01 to 50 g / 10 min, preferably 0.05 to 30 g / 10 min, more preferably 0.1 to 50 g / 10 min. 10 g / 10 min. MFR is 0.0
If it is less than 1 g / 10 minutes, the fluidity (sheet moldability) is reduced, and if it exceeds 50 g / 10 minutes, the strength is reduced.

The (c) molecular weight distribution (Mw / Mn) of the linear low density polyethylene (A) in the present invention is 1.5 to 1.5.
The range is 4.5, preferably 2.0 to 4.0, and more preferably 2.5 to 3.0. If Mw / Mn is less than 1.5, the moldability is poor, and if Mw / Mn exceeds 4.5, the tear strength, impact resistance and the like are poor. Here, the molecular weight distribution (Mw / Mn) of the linear low-density polyethylene is obtained by calculating the weight average molecular weight (Mw) and the number average molecular weight (Mn) by gel permeation chromatography (GPC), and calculating the ratio (Mw / Mn). Mn).

The linear low-density polyethylene (A) in the present invention is obtained, for example, from the integrated elution curve of the elution temperature-elution amount curve (TREF) as shown in FIG. The temperature T _{25 at which} 25% of the total elutes
The difference T ₇₅ -T ₂₅ and the density d of the temperature T ₇₅ the entire 75% is eluted When, and satisfies the following relationship (Equation 1). When the equation _{(1) T 75 -T 25 ≦ -670} × d + 644 T 75 -T 25 and density d do not satisfy the relation of the equation (1) becomes as low-temperature heat-sealing property is inferior.

The method of measuring TREF is as follows. First, a sample is added to ODCB to which an antioxidant (for example, butylhydroxytoluene) has been added so that the sample concentration becomes 0.05% by weight, and heated and dissolved at 135 ° C. 5 ml of this sample solution is injected into a column filled with glass beads, cooled to 25 ° C. at a cooling rate of 0.1 ° C./min, and the sample is deposited on the surface of the glass beads. Next, while flowing ODCB through this column at a constant flow rate, the column temperature was raised to 50 ° C.
The sample is sequentially eluted while heating at a constant rate of / hr. At this time, the concentration of the sample eluted in the solvent is continuously detected by measuring the absorption of the asymmetric stretching vibration of methylene at a wave number of 2925 cm ^-1 with an infrared detector.
From this value, the concentration of the ethylene copolymer in the solution is quantitatively analyzed to determine the relationship between the elution temperature and the elution rate. According to the TREF analysis, a change in the elution rate with respect to a temperature change can be continuously analyzed with a very small amount of sample, so that a relatively fine peak which cannot be detected by the fractionation method can be detected.

The (A) linear low-density polyethylene of the present invention further satisfies the requirements of (e) and (f) described later, (A1) a linear low-density polyethylene, or (g) and (g) described below. Preferably, it is any one of (A2) linear low-density polyethylene satisfying the requirement of h).

In the present invention, (A1) the amount X of the ODCB-soluble component at 25 ° C. of the linear low-density polyethylene X
(Weight%), the density d and the MFR satisfy the relationship of the following (Equation 2) and (Equation 3). (Equation 2) When d−0.008 log MFR ≧ 0.93, X <2.0 (Equation 3) When d−0.008 log MFR <0.93, X <9.8 × 10 ³ × (0.9300−d + 0.008)
log MFR) ² +2.0, preferably X <1.0 d−0.008 log MFR <0.93, d <0.008 log MFR <0.93, X <7. 4 × 10 ³ × (0.9300−d + 0.008
log MFR) ² +2.0, more preferably X <0.5 d-0.008 log MFR ≧ 0.93, X <0.5 d−0.008 log MFR <0.93, X <5 0.6 × 10 ³ × (0.9300−d + 0.008
log MFR) ² +2.0.

Here, the amount X of the ODCB-soluble component at 25 ° C. is measured by the following method. Sample 0.5
g in 20 ml ODCB at 135 ° C. for 2 hours,
After completely dissolving the sample, cool it to 25 ° C. After leaving this solution at 25 ° C. overnight, the filtrate is collected by filtering through a Teflon filter. This filtrate, which is a sample solution, was subjected to infrared spectroscopy to measure the asymmetric stretching vibration wave number of methylene 2925c.
The absorption peak intensity around m ^-1 is measured, and the sample concentration is calculated from a calibration curve created in advance. From this value, the ODCB-soluble content at 25 ° C. is determined.

The ODCB-soluble component at 25 ° C. is a high branching degree component and a low molecular weight component contained in linear low-density polyethylene, which causes a decrease in heat resistance and a sticky surface of a molded product, and causes a problem of hygiene. This content is desirably small, because it causes blocking of the inner surface of the molded body.
The amount of ODCB solubles is affected by the α-olefin content and molecular weight of the entire copolymer, ie, density and MFR. Therefore, these indices density, MFR and OD
The fact that the amount of the CB-soluble component satisfies the above relationship indicates that the uneven distribution of the α-olefin contained in the whole copolymer is small.

The (A1) linear low-density polyethylene according to the present invention can be obtained by (f) continuous heating elution fractionation (TRE).
In the elution temperature-elution amount curve obtained by F), a plurality of peaks are present. It is particularly preferred that the plurality of peak temperatures be between 85 ° C and 100 ° C. The presence of this peak increases the melting point, increases the crystallinity, and improves the heat resistance and rigidity of the molded body.

As shown in FIG. 1, (A1) linear low-density polyethylene was subjected to a continuous heating elution fractionation method (TR).
The peak is substantially a specific linear low-density polyethylene (ethylene / α-olefin copolymer) having a plurality of peaks in the elution temperature-elution amount curve obtained by EF). on the other hand,
The ethylene copolymer shown in FIG.
EF) is a linear low-density polyethylene having substantially one peak in an elution temperature-elution amount curve obtained by EF), and is a conventional typical metallocene-based catalyst.
An α-olefin copolymer corresponds to this.

As shown in FIG. 3, (A2) the linear low-density polyethylene of the present invention has one peak of an elution temperature-elution amount curve obtained by (g) a continuous heating elution fractionation method (TREF), In addition, T ₇₅ −T ₂₅ and the density d satisfy the following relationship (Equation 4). When the equation _{(4) T 75 -T 25 ≧ -300} × d + 285 T 75 -T 25 and density d do not satisfy the relation of the equation (4) will heat seal strength and heat resistance are poor. The (A2) linear low-density polyethylene of the present invention has (h) one or two melting point peaks, and the highest melting point T _ml and the density d among them satisfy the relationship of the following (formula 5). Things. (Formula 5) _Tml ≧ 150 × d−17 If the melting point Tm1 and the density d do not satisfy the relationship of the above (Formula 5), the heat resistance will be poor.

Further, among the linear low-density polyethylenes (A2), linear low-density polyethylenes that further satisfy the following requirement (i) are preferable. (I) The melt tension (MT) and the melt flow rate (MFR) satisfy the relationship of the following (Equation 6) (Equation 6) logMT ≦ −0.572 × logMFR + 0.3 By satisfying the relationship (1), the moldability of the thermoforming laminated sheet or the like becomes good.

As shown in FIG. 3, the (A2) linear low-density polyethylene has one TREF peak as shown in FIG. 4) is not satisfied, and is distinguished from a conventional typical metallocene-based catalyst-based ethylene copolymer.

The linear low-density polyethylene (A) in the present invention is not particularly limited to a catalyst, a production method and the like as long as the above-mentioned parameters are satisfied, but it is preferable that the organic cyclic compound has at least a conjugated double bond. And Periodic Table No.
A linear ethylene (co) polymer obtained by (co) polymerizing ethylene and an α-olefin in the presence of a catalyst containing a Group IV transition metal compound is preferred. Such a linear ethylene (co) polymer has a narrow molecular weight distribution and a narrow composition distribution, and thus has excellent mechanical properties, excellent heat sealing properties, excellent heat blocking properties, and the like, and has good heat resistance. .

In the production of (A) the linear low-density polyethylene in the present invention, it is particularly desirable to polymerize with a catalyst obtained by mixing the following compounds a1 to a4. a1: Compound represented by the general formula Me ¹ R ¹ _p R ² _q (OR ³ ) _r X ¹⁴ _-pqr (where Me ¹ represents zirconium, titanium, or hafnium, and R ¹ and R ³ each represent a carbon number) 1 to
24 hydrocarbon groups, R ² is a 2,4-pentanedionato ligand or a derivative thereof, a benzoylmethanato ligand,
A benzoylacetonate ligand or a derivative thereof, X ¹ represents a halogen atom, p, q and r each represent 0 ≦ p
≦ 4, 0 ≦ q ≦ 4, 0 ≦ r ≦ 4, 0 ≦ p + q + r ≦ 4) a2: a compound represented by the general formula Me ² R ⁴ _m (OR ⁵ ) _n X ² _zmn (In the formula, Me ² is an element in Groups I to III of the periodic table, R ⁴
And R ⁵ are each a hydrocarbon group having 1 to 24 carbon atoms, X
² represents a halogen atom or a hydrogen atom (however, when X ² is a hydrogen atom, Me ² is limited to a Group III element of the periodic table), z represents a valence of Me ² , and m and n represent A is an integer satisfying the ranges of 0 ≦ m ≦ z and 0 ≦ n ≦ z, and 0 ≦ m + n ≦ z. A3: Organic cyclic compound having a conjugated double bond a4: Al—O—Al bond Containing modified organoaluminum oxy compound and / or boron compound

The details will be described below. The above-mentioned catalyst component a1
In the formula of the compound represented by the general formula Me ¹ R ¹ _p R ² _q (OR ³ ) _r X ¹⁴ _-pqr , Me ¹ represents zirconium, titanium or hafnium, and the types of these transition metals are limited. It is not limited to this, and a plurality of them can be used, but it is particularly preferable that the copolymer contains zirconium having excellent weather resistance. R ¹ and R ³ are each a hydrocarbon group having 1 to 24 carbon atoms, preferably 1 to 12 carbon atoms, and more preferably 1 to 8 carbon atoms. Specifically, an alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group;
Alkenyl groups such as vinyl group and allyl group; phenyl group,
Aryl groups such as tolyl, xylyl, mesityl, indenyl and naphthyl; benzyl, trityl,
And aralkyl groups such as phenethyl group, styryl group, benzhydryl group, phenylbutyl group, and neofuyl group. These may have branches. R ² is 2,
It shows a 4-pentanedionato ligand or a derivative thereof, a benzoylmethanato ligand, a benzoylacetonato ligand or a derivative thereof. X ¹ represents a halogen atom such as fluorine, iodine, chlorine and bromine. p and q are respectively 0 ≦ p ≦ 4, 0 ≦ q ≦ 4, 0 ≦ r ≦ 4, 0 ≦ p + q
An integer satisfying the range of + r ≦ 4 is an integer.

Examples of the compounds represented by the general formula of the above-mentioned catalyst component a1 include tetramethyl zirconium, tetraethyl zirconium, tetrabenzyl zirconium, tetrapropoxy zirconium, tripropoxy monochlorodiconium, tetraethoxy zirconium, tetrabutoxy zirconium, tetrabutoxy titanium , Tetrabutoxy hafnium and the like, and especially Z such as tetrapropoxy zirconium and tetrabutoxy zirconium.
r (OR) ₄ compounds are preferred, and two or more of these may be used in combination. Specific examples of the 2,4-pentanedionato ligand or derivative thereof, benzoylmethanato ligand, benzoylacetonato ligand or derivative thereof include tetra (2,4-pentanedionato) zirconium. , Tri (2,4-pentanedionato)
Zirconium chloride, di (2,4-pentanedionato) dichloride zirconium, (2,4-pentanedionato) trichloride zirconium, di (2,4-pentanedionato) diethoxide zirconium, di (2,4- Pentanedionato) di-n-propoxide zirconium, di (2,4-pentanedionato) di-n
-Butoxide zirconium, di (2,4-pentanedionato) dibenzyl zirconium, di (2,4-pentanedionato) dineofylzirconium, tetra (dibenzoylmethanato) zirconium, di (dibenzoylmethanato) die Zirconium toxide, zirconium di (dibenzoylmethanato) di-n-propoxide, zirconium di (dibenzoylmethanato), zirconium di (n-butoxide), zirconium diethoxide zirconium, di (benzoylacetonate) ) Di-n-propoxide zirconium, di (benzoylacetonate)
And di-n-butoxide zirconium.

The general formula Me of the catalyst component a2^TwoR^Four _m(O
R^Five)_nX^Two _zmn In the formula of the compound represented by^Two Is the period
Represents a group I-III element of the table, lithium, sodium,
Potassium, magnesium, calcium, zinc, boron,
Aluminum and the like. R^FourAnd R^Five Is charcoal
A hydrocarbon group having a prime number of 1 to 24, preferably a carbon number of 1 to 1
2, more preferably 1 to 8, specifically
Group, ethyl group, propyl group, isopropyl group, butyl
Alkyl groups such as vinyl groups; alkene groups such as vinyl groups and allyl groups
Nyl group: phenyl group, tolyl group, xylyl group, mesityl
An aryl group such as a group, an indenyl group or a naphthyl group;
Jyl, trityl, phenethyl, styryl, ben
Such as a duhydryl group, a phenylbutyl group and a neofuyl group
Aralkyl groups and the like. These have branches
Is also good. X^Two Is fluorine, iodine, chlorine and bromine, etc.
Represents a halogen atom or a hydrogen atom. However
Then X ^Two Is Me when hydrogen is a hydrogen atom^Two Is boron, aluminum
Only in the case of Group III elements in the periodic table
Things. Z is Me^Two And m and m
And n satisfy the ranges of 0 ≦ m ≦ z and 0 ≦ n ≦ z, respectively.
Is an integer, and 0 ≦ m + n ≦ z.

Examples of the compound represented by the general formula of the catalyst component a2 include organic lithium compounds such as methyllithium and ethyllithium; organic magnesium compounds such as dimethylmagnesium, diethylmagnesium, methylmagnesium chloride and ethylmagnesium chloride; Organic zinc compounds such as zinc and diethyl zinc; organic boron compounds such as trimethyl boron and triethyl boron; trimethyl aluminum, triethyl aluminum, tripropyl aluminum, triisobutyl aluminum, trihexyl aluminum, tridecyl aluminum, diethyl aluminum chloride, ethyl aluminum dichloride , Ethyl aluminum sesquichloride, diethyl aluminum ethoxide, diethyl aluminum Derivatives of organoaluminum compounds such as Idoraido the like.

The organic cyclic compound having a conjugated double bond of the catalyst component a3 has one or more rings having two or more, preferably two to four, more preferably two to three conjugated double bonds. A cyclic hydrocarbon compound having 2 or more and having a total carbon number of 4 to 24, preferably 4 to 12; wherein the cyclic hydrocarbon compound partially has 1 to 6 hydrocarbon residues (typically, carbon A cyclic hydrocarbon compound substituted with an alkyl group or an aralkyl group of the formulas 1 to 12; two or more, preferably 2 to 4, more preferably 2 to 2, conjugated double bonds.
One or more rings having three rings and a total carbon number of 4
An organosilicon compound having a cyclic hydrocarbon group of from 24 to 24, preferably 4 to 12; said cyclic hydrocarbon group being partially substituted by 1 to 6 hydrocarbon residues or an alkali metal salt (sodium or lithium salt) Organosilicon compounds. Particularly preferably, those having a cyclopentadiene structure in any of the molecules are desirable.

The preferred compounds include cyclopentadiene, indene, azulene and their alkyl, aryl, aralkyl, alkoxy or aryloxy derivatives. Further, a compound obtained by bonding (crosslinking) these compounds via an alkylene group (the number of carbon atoms of which is usually 2 to 8, preferably 2 to 3) is also preferably used.

The organosilicon compound having a cyclic hydrocarbon group can be represented by the following general formula. A _L SiR _4-L wherein A represents the above-mentioned cyclic hydrogen group exemplified by a cyclopentadienyl group, a substituted cyclopentadienyl group, an indenyl group, and a substituted indenyl group, and R represents a methyl group, an ethyl group, a propyl group. Alkyl groups such as methoxy, ethoxy, propoxy and butoxy groups; aryl groups such as phenyl groups; aryloxy groups such as phenoxy groups; aralkyl groups such as benzyl groups. And represents a hydrocarbon residue having 1 to 24 carbon atoms, preferably 1 to 12 carbon atoms or hydrogen, and L represents 1
≦ L ≦ 4, preferably 1 ≦ L ≦ 3.

Specific examples of the organic cyclic hydrocarbon compound of the component a3 include cyclopentadiene, methylcyclopentadiene, ethylcyclopentadiene, 1,3-dimethylcyclopentadiene, indene, 4-methyl-1-indene, 4,7- C5-C24 cyclopolyene or substituted cyclopolyene such as dimethylindene, cycloheptatriene, methylcycloheptatriene, cyclooctatetraene, azulene, fluorene, methylfluorene, monocyclopentadienylsilane, biscyclopentadiene Examples include enylsilane, triscyclopentadienylsilane, monoindenylsilane, bisindenylsilane, and trisindenylsilane.

The modified organoaluminum oxy compound containing an Al—O—Al bond of the catalyst component a4 is obtained by reacting an alkylaluminum compound with water to obtain a modified organoaluminum oxy compound usually called aluminoxane. The molecule usually contains 1 to 100, preferably 1 to 50 Al-O-Al bonds. The modified organic aluminum oxy compound may be linear or cyclic.

The reaction between the organoaluminum and water is usually carried out in an inert hydrocarbon. As the inert hydrocarbon,
Aliphatic, alicyclic and aromatic hydrocarbons such as pentane, hexane, heptane, cyclohexane, benzene, toluene and xylene are preferred. The reaction ratio between water and the organoaluminum compound (water / Al molar ratio) is usually 0.25 / 1 to 1.2.
/ 1, preferably 0.5 / 1 to 1/1.

Examples of the boron compound include triethylaluminum tetra (pentafluorophenyl) borate (triethylammoniumtetra (pentafluorophenyl)
Borate, dimethylanilinium tetra (pentafluorophenyl) borate (dimethylanilinium tetra (pentafluorophenyl) borate, butylammonium tetra (pentafluorophenyl) borate, N, N-
Dimethylanilinium tetra (pentafluorophenyl) borate, N, N-dimethylaniliniumtetra (3,5 difluorophenyl) borate and the like can be mentioned.

The above catalyst may be used by mixing and contacting a1 to a4, but it is preferable to use the catalyst by supporting it on an inorganic carrier and / or a particulate polymer carrier (a5). Examples of the inorganic carrier and / or the particulate polymer carrier (a5) include a carbonaceous material, a metal, a metal oxide, a metal chloride, a metal carbonate or a mixture thereof, a thermoplastic resin, and a thermosetting resin. Suitable metals that can be used for the inorganic carrier include iron, aluminum, nickel and the like. Specifically, Si
O ₂ , Al ₂ O ₃ , MgO, ZrO ₂ , TiO ₂ , B ₂ O ₃ ,
CaO, ZnO, BaO, ThO ₂ and the like or mixtures _{thereof, SiO 2 -Al 2 O 3,} SiO 2 -V
₂ O ₅ , SiO ₂ —TiO ₂ , SiO ₂ —V ₂ O ₅ , SiO ₂ —
MgO, SiO ₂ —Cr ₂ O _{3 and the} like. Among these, those containing at least one component selected from the group consisting of SiO ₂ and Al ₂ O ₃ as a main component are preferable. Further, as the organic compound, any of a thermoplastic resin and a thermosetting resin can be used. Specifically, particulate polyolefin, polyester, polyamide, polyvinyl chloride, polymethyl (meth) acrylate, polystyrene, poly Examples include norbornene, various natural polymers, and mixtures thereof.

The above-mentioned inorganic carrier and / or particulate polymer carrier can be used as they are, but preferably, as a pretreatment, these carriers are converted to an organic aluminum compound or a modified organic aluminum compound containing an Al—O—Al bond. After the contact treatment, it can be used as the component a5.

The method for producing (A) the linear low-density polyethylene according to the present invention is carried out by a gas phase polymerization method, a slurry polymerization method, a solution polymerization method or the like in the presence of the above-mentioned catalyst and substantially no solvent. In a state where oxygen, water, etc. are cut off, aliphatic hydrocarbons such as butane, pentane, hexane, heptane, aromatic hydrocarbons such as benzene, toluene and xylene, alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, etc. It is produced in the presence or absence of an inert hydrocarbon solvent exemplified in (1). The polymerization conditions are not particularly limited, but the polymerization temperature is usually 15 to 350 ° C, preferably 20 to
To 200 ° C, more preferably 50 to 110 ° C,
The polymerization pressure is usually from normal pressure to 70 kg / cm ^{2 in} the case of the low and medium pressure method.
G, preferably normal pressure to 20 kg / cm ² G, the case of high pressure process typically 1500 kg / cm ² G or less.
The polymerization time is usually from 3 minutes to 10 hours, preferably from 5 minutes to 5 hours in the case of the low and medium pressure method. In the case of the high-pressure method, it is usually 1 minute to 30 minutes, preferably about 2 minutes to 20 minutes. In addition, the polymerization is not particularly limited to a single-stage polymerization method, as well as a multi-stage polymerization method of two or more stages in which polymerization conditions such as hydrogen concentration, monomer concentration, polymerization pressure, polymerization temperature, and catalyst are different from each other. As a particularly preferred production method, a method described in JP-A-5-132518 is exemplified.

The (A) linear low-density polyethylene of the present invention is produced by using a catalyst containing no halogen such as chlorine in the above-mentioned catalyst components, so that the halogen concentration is at most 10 ppm or less, preferably at most 10 ppm. Is 5 ppm
Hereinafter, it is more preferably substantially free of (ND: 2p
pm or less). By using such a halogen-free linear low-density polyethylene such as chlorine, it is not necessary to use an acid neutralizer as in the past, and the chemical stability and hygiene are excellent, and especially, food packaging materials and the like. The laminated sheet for thermoforming suitably used in the field of (1) can be provided.

The mixing ratio of (A) the linear low-density polyethylene in the resin material (iii) for forming the layer III is from 50 to 1
00% by weight, preferably 70 to 100% by weight. (A) 50% by weight of linear low density polyethylene
If less, heat resistance, pinhole resistance, heat sealability,
ESCR resistance and mechanical strength decrease.

Other polyethylene polymers that can be blended with the resin material (iii) include high-, medium- and low-pressure methods using a Ziegler-type catalyst and the like, and other known methods, such as ethylene homopolymers, ethylene and C3-C3. And an ethylene-based (co) polymer obtained by a high-pressure radical polymerization method.

High / medium /
An ethylene homopolymer or a copolymer of ethylene and an α-olefin having 3 to 12 carbon atoms by a low pressure method or another known method has a density of 0.94 to 0.97 g / cm ^3.
High density polyethylene with a density of 0.91 to 0.94 g /
cm ³ linear low density polyethylene (LLDPE), density 0.86-0.91 g / cm ³ very low density polyethylene (VLDPE), density 0.86-0.91 g / c
m ³ of ethylene-propylene copolymer rubber, ethylene-
Ethylene / α-olefin copolymer rubber such as propylene / diene copolymer rubber can be mentioned.

The LLDPE using the Ziegler type catalyst is defined as ethylene • α-density having a density of 0.91 to 0.94 g / cm ³ , preferably 0.91 to 0.93 g / cm ^3.
An olefin copolymer, wherein the α-olefin has 3 to 20 carbon atoms, preferably 4 to 12 carbon atoms, and specifically includes propylene, 1-butene, and 4-methyl-
1-pentene, 1-hexene, 1-octene and the like can be mentioned.

The ultra low density polyethylene (VLDPE) using the Ziegler type catalyst has a density of 0.86 to
0.91 g / cm ³ , preferably 0.88 to 0.905
It is an ethylene / α-olefin copolymer in the range of g / cm ³ and is a polyethylene having properties intermediate between LLDPE and ethylene / α-olefin copolymer rubber (EPR, EPDM).

The above-mentioned ethylene / α-olefin copolymer rubber includes ethylene / propylene copolymer rubber and ethylene / propylene / diene copolymer rubber having a density of 0.86 to less than 0.91 g / cm ^3. Examples of the ethylene / propylene rubber include those obtained by adding a random copolymer (EPM) containing ethylene and propylene as main components, and a diene monomer (dicyclopentadiene, ethylidene norbornene, etc.) as a third component. A random copolymer (EPDM) as a main component is exemplified.

The resin material (i) and the resin material (ii) in the present invention may contain known additives and fillers. Further, in the resin material (iii), by using (A) linear low-density polyethylene produced by using a halogen-free catalyst and not adding additives such as an antioxidant and a neutralizing agent, A clean molded body can be provided.

Further, in the present invention, an antioxidant, an antiblocking agent, a lubricant,
No known additives such as an antistatic agent, an antifogging agent, an ultraviolet absorber, an organic or inorganic pigment, a nucleating agent, and a cross-linking agent are added, or additives are added to the resin composition. Even so, it is desirable that the compounded additive is an additive that does not substantially migrate to the contacted object such as the contents. In the present invention, an additive that elutes to the outside,
For example, when the content is a liquid, the resin material (iii) contains an additive that is eluted in the liquid, an additive that transfers odor, or an additive that is unevenly distributed on the film surface over time. , It is possible to provide a sanitary and clean thermoforming laminated sheet and container with less odor.

In the present invention, the additive which does not substantially migrate to the contacted object is a filler such as an organic or inorganic filler, which does not degrade the contacted object and has the properties of the resin sheet of the present invention. Is an additive that can be added within a range that does not essentially inhibit the above. As inorganic fillers, calcium carbonate, talc, silica, clay, carion, alumina,
Aluminum hydroxide, magnesia, magnesium hydroxide, calcium sulfate, calcium sulfite, barium sulfate, aluminum silicate, calcium silicate, sodium silicate, potassium silicate, magnesium carbonate, barium carbonate,
Examples include calcium oxide, titanium oxide, zinc oxide, mica, glass flake, zeolite, diatomaceous earth, perlite, permiculite, shirasu balloon, glass microsphere, fly ash, and glass beads.
Examples of the organic filler include a crosslinked product of polymethyl methacrylate, a crosslinked product of polyethylene terephthalate, phenol resin and other synthetic resin powders and fine beads, wood powder, pulp powder, and the like. These fillers can be compounded for the purpose of improving the rigidity of the laminated sheet for thermoforming.

The laminated sheet for thermoforming of the present invention is characterized in that
A first layer I made of a resin material (i) containing PE as a main component,
A second layer composed of the resin material (ii) containing the high-pressure radical method ethylene polymer as a main component; and a third layer composed of the resin material (iii) containing the (A) linear low-density polyethylene as a main component. It has.

In the laminated sheet for thermoforming of the present invention, when formed into a container, the layer corresponding to the innermost layer of the container is made of the third layer.
It is important to form in layers. In particular, the properties of each layer (Layer I: water vapor transmission resistance, fragrance retention, Layer II: thermoformability, transparency, flexibility, Layer III: heat resistance, pinhole resistance, heat sealability, resistance In order to take advantage of ESCR properties,
It is preferable that the layers are stacked in the order of layer / second layer / third layer. Another layer may be interposed between the II layer and the I layer or between the II layer and the III layer. Other layers include an adhesive resin layer for more firmly bonding the layer II with the layers I and III on both sides thereof.

The thickness of the laminated sheet for thermoforming of the present invention is preferably 50 μm to 5 mm from the viewpoint of ease of use. In order to sufficiently exhibit the properties of each layer, the thickness of the first layer of the laminated sheet for thermoforming of the present invention is 10 μm to 1 μm.
mm, and the thickness of each of the second and third layers is desirably selected in the range of 20 μm to 2 mm.
Also, the thickness ratio of each layer (the I-th layer / the II-th layer / the III-th layer)
In terms of the balance between the thermoformability and the physical properties of the sheet, 1-2
/ 1 to 3/1 to 3 are preferable.

The laminated sheet for thermoforming of the present invention may further have a barrier layer (IV). Barrier layer (IV)
The gas barrier properties (water vapor transmission resistance, fragrance retention, and moisture resistance) are further improved by providing. Examples of the barrier layer (IV) include plastic films or sheets of polypropylene resin, polyamide resin, polyester resin, saponified ethylene-vinyl acetate copolymer, polyvinylidene chloride, polycarbonate, etc. (stretched and printed materials thereof). And metal foils or metal plates of aluminum, iron, copper, alloys containing these as a main component without departing from the spirit of the present invention. , Cellophane,
Paper, woven fabric, non-woven fabric and the like may be used in some cases.

Further, any one of the layers I, II and III may be made of a resin material (i), a resin material (ii) and a resin material obtained by recycling a laminated sheet for thermoforming. It may be formed of the blend resin of (iii). Moreover, the laminated sheet for thermoforming of the present invention may further have a recycled resin layer (V) composed of the blend resin. Here, the blended resin obtained by recycling the thermoforming laminated sheet is a defective product of the thermoforming laminated sheet, a recovered product of the container formed of the thermoforming laminated sheet, a finishing step after processing into a container or the like. It is a mixed resin obtained by pulverizing generated burrs and the like. As described above, the laminated sheet for thermoforming of the present invention can use a recycled blended resin, and has good recyclability.

Examples of the laminated sheet for thermoforming include I
/ II / III, I / IV / II / III, IV / I / II / III, I /
Adhesive / V / adhesive / II / III. More specifically, HD / LD / LL, HD + LL /
LD / LL, HD / LD + LL / LL, HD / LD / L
L + LD, HD + LL / LD / LL + LD, HD / RC
/ LD / LL, RC / HD / LD / LL, RC / LD /
LL, RC + HD / LD / LL, HD / RC + HD / L
D / LL, HD / adhesive / barrier layer (EVOH, P
A, PEs, OPP, etc.) / Adhesive / LD / LL etc. (here, HD: high density polyethylene, L
D: high-pressure radical polymerization low-density polyethylene, LL: linear low-density polyethylene, RC: recycled blend resin, EVOH: saponified ethylene-vinyl acetate copolymer, PA: polyamide resin, PEs: polyester resin, OPP : Oriented polypropylene resin, adhesive: acid-modified polyethylene resin).

The laminated sheet for thermoforming of the present invention can be produced by various methods.
Manufactured by molding the layers, layers II and III by coextrusion. As a molding method, for example,
It can be manufactured with high productivity by a multilayer inflation molding method, a multilayer cast molding method, or the like. Among them, a multilayer inflation molding method is suitably used in terms of economy, moldability, and the like.

The production of a sheet by the multilayer inflation molding method can be performed by a conventional air-cooled inflation film production apparatus.
Extruded through a circular die from an extruder at a temperature of 250 ° C., contacted with air blown from an air-cooled air ring, quenched, solidified, and taken out with a pinch roll.
It is performed by winding it around a frame.

In the multilayer inflation molding method, it is preferable that the innermost layer is formed of the resin material (i) containing the high-density polyethylene of the I-th layer as a main component. According to such a method, the inner surface becomes HDPE, so that the workability is improved due to the excellent antiblocking property. In addition to the air-cooled inflation molding, it can be manufactured by a water-cooled inflation molding, a T-die method, or the like, and a sheet having excellent transparency, low-temperature impact resistance, and the like can be obtained.

Also, a hollow tube obtained by multilayer inflation molding of at least the resin material (i), the resin material (ii) and the resin material (iii) is sandwiched and crushed to form a laminated sheet for thermoforming of 5 or more layers. It is also possible to use As a method of obtaining such a laminated sheet for thermoforming, a hollow tube formed by extruding each resin material through a circular die is pinched and crushed with a pinch roll at a temperature higher than the melting point of the resin material of the inner layer. How and
A method in which a hollow tube formed by extruding each resin material through a circular die is brought into contact with air blown from an air-cooled air ring to cool and solidify, and then crushed by a heated pinch roll is used. According to such a manufacturing method, a thick laminated sheet can be obtained.

As described above, by manufacturing a laminated sheet for thermoforming by a multilayer inflation molding method,
There is no unevenness like the sheet obtained by the T-die method, the resin is uniformly crystallized due to slow cooling by air cooling, it becomes a strong sheet, and it can be molded without additives because it can be molded at low temperature, Blow-up ratio (BUR) can be adjusted to obtain a sheet that does not adversely affect the contacted object,
Quality control is possible. Compared with T-die method,
There is no ear loss, high productivity and economical advantage.By multi-layering and crushing with pinch rolls, double-thickness sheets can be molded at once and the thickness can be homogenized. Is obtained.

[0079]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

The test method in this example is as follows. [Density] Based on JIS K6760. [MFR] Based on JIS K6760. [Mw / Mn] GPC (150C type manufactured by Waters)
And 135 ° C. ODCB was used as a solvent. The column used was Shodex HT806M. [TREF] With the column maintained at 140 ° C., a sample was injected into the column, the temperature was lowered to 25 ° C. at 0.1 ° C./min, and the polymer was deposited on glass beads. The concentration of the polymer eluted at each temperature after the temperature was raised was detected by an infrared detector. (Solvent: ODCB, flow rate: 1 ml /
Min, heating rate: 50 ° C./hr, detector: infrared spectrometer (wavelength: 2925 cm ⁻¹ ), column: 0.8 cmφ × 12 cm
L (filled with glass beads), sample concentration: 0.05% by weight)

<Evaluation of Laminated Sheet> [Thermoformability] As the evaluation of the thermoformability, the drawdown resistance and the vacuum moldability were evaluated. 1) Drawdown resistance The laminated sheet was clamped and fixed to a stainless steel fitting having an inner size of 30 cm square. The laminated sheet was heated together with 210 ° C. in advance, and the laminated sheet was horizontally inserted into an oven maintained at this temperature. After the laminated sheet changes to an irregular shape upon melting, the laminated sheet central portion hangs down by heating and melting from the time (T1) when the laminated sheet is stretched back due to the molecular orientation and melt tension of the laminated sheet, and the lower surface of the laminated sheet is shifted from the horizontal line of the character. The measurement was performed up to the time (T2) at which the lens hanged by 15 mm, and T2-T1 (sec) was determined as an index of the drawdown resistance. The larger this value is, the less sag during thermoforming and the easier the molding.

2) Vacuum Formability Using a model FLX-02 manufactured by Asano Laboratories Co., Ltd., vacuum forming was performed in the shape of a pudding container (opening diameter 64 mm, bottom diameter 50 mm, depth 52 mm) under the following conditions. Based on the appearance of the molded article, evaluation of vacuum formability such as presence or absence of wrinkles, uneven thickness, and occurrence of holes was performed. (Molding conditions) Plug assist: Yes (assist rate 43%) Upper heater temperature: 450 ° C Lower heater temperature: 450 ° C Heating time: 15 seconds Upper table delay: 1 second Upper table time: 10 seconds Lower table delay: 0.8 Second Lower table time: 10 seconds Mold temperature: 60 ° C Vacuum delay: 3 seconds Cooling time: 10 seconds Release time: 1.7 seconds

[Heat Seal Strength] Tester Sangyo Co., Ltd.
Using a heat seal tester (seal bar width 1 mm, seal pressure 2 kg / cm ² ), the innermost (third layer) faces of the laminated sheet for thermoforming were sealed at a seal temperature of 165 ° C. for 1 second, and a room temperature of 23. After conditioning for 24 hours at 50 ° C. and 50% humidity, the seal portion was cut into strips with a width of 15 mm, and the seal portion was peeled off at 300 mm / min with a tensile tester.
The maximum load was measured. [Pinhole Resistance] A test piece having a width of 200 mm and a length of 300 mm was cut out from the laminated sheet for thermoforming in the flow direction during molding. The test piece was attached to a gelbo flex tester manufactured by Rigaku Kogyo Co., Ltd., and after loading 3,000 strokes at room temperature, the number of pinholes in the test piece was measured. The same test was repeated three times, and the average value of the number of pinholes was obtained. [Water vapor transmission rate] Based on JIS K7129. [Haze] Based on ASTM D1003. [Tensile modulus] MD (extrusion direction) was measured in accordance with ASTM D882. [Tensile impact value] According to ASTM D1822, MD
(Extrusion direction) was measured.

Various components used in Examples and Comparative Examples are as follows. (1) High-density polyethylene ethylene / 1-butene copolymer (HDPE-1) MFR = 1.0 g / 10 min, density = 0.956 g / cm
^3. Nippon Polyolefin Co., Ltd. (2) High density polyethylene ethylene / 1-butene copolymer (HDPE-2) MFR = 0.5 g / 10 min, density = 0.950 g / cm
^3. Nippon Polyolefin Co., Ltd.

(3) Linear low-density polyethylene 1) (A1) A specific linear low-density polyethylene was polymerized by the following method. [Preparation of solid catalyst] To a catalyst preparation device equipped with an electromagnetic induction stirrer, 1000 ml of toluene purified under nitrogen, 22 g of tetraethoxyzirconium (Zr (OEt) ₄ ) and 74 g of indene were added. 100 g of aluminum is dropped over 100 minutes,
Thereafter, the reaction was carried out at the same temperature for 2 hours. After cooling to 40 ° C., a toluene solution of methylalumoxane (concentration: 2.5 m
(mol / ml) and stirred for 2 hours.
Next, silica (manufactured by Grace, # 952, surface area 300 m ² / g) 2 previously calcined at 450 ° C. for 5 hours 2
After stirring at room temperature for 1 hour, nitrogen blowing and drying under reduced pressure were performed at 40 ° C. to obtain a solid catalyst having good fluidity.

[Gas phase polymerization] Continuous type fluidized bed gas phase polymerization apparatus
At a polymerization temperature of 80 ° C. and a total pressure of 20 kgf / cm ^Two In G
Copolymerization of ethylene and 1-hexene was performed. The solid touch
The medium is fed continuously, ethylene, 1-hexene and water
The polymerization is carried out by supplying the element so that the molar ratio is maintained at a predetermined value.
Tylene copolymers (LLDPE-1 and LLDPE-
2) was obtained. The physical properties are shown in Table 1.

2) (A2) The specific linear low-density polyethylene was polymerized by the following method. Using the continuous fluidized-bed gas-phase polymerization apparatus, a polymerization temperature of 75
The copolymerization of ethylene and 1-hexene was performed at a temperature of 20 ° C. and a total pressure of 20 kgf / cm ² G. Continuously supplying the solid catalyst,
Polymerization is carried out by supplying ethylene, 1-hexene and hydrogen so as to maintain a predetermined molar ratio, and an ethylene copolymer (LL)
DPE-3) was obtained. The physical properties are shown in the table.

3) Ethylene catalyzed by a general metallocene catalyst
Hexene-1 copolymer (LLDPE-4) Purified toluene was placed in a pressure reactor equipped with a stirrer and purged with nitrogen, then 1-hexene was added, and bis (n-
A mixture of (butylcyclopentadienyl) zirconium dichloride and methylalumoxane (MAO) was mixed with (Al /
(Zr molar ratio = 500), and the temperature was raised to 80 ° C. to prepare a metallocene catalyst. Then, add ethylene,
While continuously polymerizing ethylene, the polymerization was carried out while maintaining the total pressure at 6 kg / cm ³ to produce an ethylene / hexene-1 copolymer (LLDPE-4). The physical properties are shown in Table 1.

4) Commercial linear low density polyethylene (LLD)
PE-5) Physical properties are shown in Table 1.

[0090]

[Table 1]

(4) High-pressure low-density polyethylene: HP-
LDPE-1 MFR = 1.0 g / 10 min, density = 0.924 g /
cm ³ (5) High pressure method low density polyethylene: HP-LDPE-2 MFR = 0.3 g / 10 min, density = 0.923 g /
cm ³ , manufactured by Nippon Polyolefin Co., Ltd.

[Examples 1, 3 to 9, Comparative Examples 1 to 4, Reference Examples 1 to 2] A predetermined amount of an antioxidant (Irganox 107
6, Irgafos 168) and calcium stearate (neutralizing agent) in combination with HDPE and HP shown in Tables 2 to 4.
-LDPE and LLDPE were manufactured by Tommy Machine Industry Co., Ltd.
Using a layer inflation molding machine (three 40 mmφ extruders), a resin material for each layer shown in Tables 2 to 4 was molded under the conditions of a molding lip gap of 3 mm and a molding temperature of 200 ° C., and the width was 300 mm. Laminated sheets for thermoforming having the layer thickness configurations shown in Tables 2 to 4 were produced. The laminated sheet for thermoforming was evaluated. The results are shown in Tables 2 to 4. [Example 2] HDPE, HP-LDPE, LL shown in Table 2 without blending an antioxidant and calcium stearate
DPE was molded in the same manner as in Example 1 to produce a laminated sheet for thermoforming, which was evaluated. Table 2 shows the results.

[0093]

[Table 2]

[0094]

[Table 3]

[0095]

[Table 4]

As is clear from the results in Tables 2 and 3, the laminated sheets for thermoforming of Examples have thermoformability, heat sealability, pinhole resistance, water vapor transmission resistance, transparency, and mechanical strength. It turns out that it is excellent.

On the other hand, as is clear from the results in Table 4, the laminated sheet for thermoforming of Comparative Example 1 was inferior in water vapor transmission resistance because HDPE was not used for the I-th layer. The laminated sheet for thermoforming of Comparative Example 2 was inferior in drawdown resistance and vacuum moldability because the high pressure radical method ethylene polymer was not used for the second layer.

The laminated sheet for thermoforming of Comparative Example 3 was made of III
Since the layer (A) did not use linear low-density polyethylene, the heat sealability was poor. The laminated sheet for thermoforming of Comparative Example 4 also had poor heat sealability because (A) the linear low-density polyethylene was not used for the third layer. Furthermore, since no linear low density polyethylene (A) was used in any of the layers, the pinhole resistance, haze, and tensile impact strength were poor. The laminated sheet for thermoforming of Reference Example 1
Since the layer is thin, the water vapor transmission resistance is inferior.
The laminated sheet for thermoforming had poor drawdown resistance and vacuum formability because the second layer was thin.

[0099]

As described above, the laminated sheet for thermoforming of the present invention has the first layer made of the resin material (i) mainly composed of high-density polyethylene having a density of 0.93 g / cm ³ or more. A second layer made of a resin material (ii) containing a high-pressure radical method ethylene polymer as a main component, and a density of 0.94 g /
Since it has a ^third layer made of a resin material (iii) mainly composed of a linear low-density polyethylene having a density of not more than ³ cm ³ , the secondary workability, that is, vacuum formability, hot plate formability, press formability, air pressure forming Excellent heat moldability and heat sealing properties such as transparency, transparency, flexibility, heat resistance, pinhole resistance,
Excellent in ESCR resistance, water vapor transmission resistance and fragrance retention.

When the thermoforming laminated sheet of the present invention is laminated in the order of the I-th layer, the II-th layer, and the III-th layer, the properties of each layer (the first layer: water vapor transmission resistance, fragrance retention) , The second layer: thermoformability, transparency, flexibility, and the third layer: heat resistance, pinhole resistance, heat sealability, and ESCR resistance). The thickness of the thermoforming laminated sheet is 50 μm to 5 mm, and the thickness of the I-th layer is 10 μm.
m to 1 mm, the thickness of each of the second and third layers is 2
When the thickness is in the range of 0 μm to 2 mm, the laminated sheet for thermoforming is easy to use, and the properties of each layer are sufficiently exhibited.

Further, if the thermoforming laminated sheet of the present invention further has a barrier layer (IV), the gas barrier properties (water vapor permeability, fragrance retention, moisture resistance) are further improved. Further, any one of the I-th layer, the II-th layer and the III-th layer is formed of a resin material (i), a resin material (ii) and a resin material (iii) obtained by recycling the thermoforming laminated sheet. Made of blended resin, or
If the recycled resin layer (V) made of the blended resin is further provided, the recycled blended resin can be used, and the recyclability is improved.

If the linear low-density polyethylene satisfies the following requirements (a) to (d), the heat resistance, heat sealability, mechanical strength, rigidity,
Formability and the like are further improved. If the linear low-density polyethylene is (A1) a linear low-density polyethylene that further satisfies the above requirements (e) and (f), the laminated sheet for thermoforming has heat resistance, hygiene, and rigidity. Is further improved. Further, the linear low-density polyethylene further satisfies the above requirements (g) and (h) (A
2) If it is a linear low-density polyethylene, the heat resistance, heat seal strength, and low temperature heat sealability of the laminated sheet for thermoforming are further improved. If the (A2) linear low-density polyethylene further satisfies the above requirement (i),
Formability of the laminated sheet for thermoforming is further improved.

The linear low-density polyethylene, an organic cyclic compound having at least a conjugated double bond, and
If it is a linear ethylene copolymer obtained by copolymerizing ethylene and α-olefin in the presence of a catalyst containing a Group IV transition metal compound, the mechanical properties and heat sealability of the laminated sheet for thermoforming , Heat blocking resistance and heat resistance are further improved. Further, if the additive blended in the resin material (iii) is an additive that does not substantially migrate to the contacted object, or if the additive is not blended in the resin material (iii), the odor is small, A laminated sheet for thermoforming having hygiene properties can be obtained. In addition, resin materials (ii
When the halogen concentration in i) is 10 ppm or less, a thermoformed laminated sheet excellent in chemical stability and hygiene and particularly suitably used in the field of food packaging materials and the like can be provided.

Further, since the method for producing a laminated sheet for thermoforming of the present invention is a method for producing the laminated sheet for thermoforming by multi-layer inflation molding, the secondary workability, that is, the vacuum formability, the hot plate formability and the like. Excellent in thermoformability and heat sealing properties such as press moldability, air pressure moldability, and transparency, flexibility, heat resistance, pinhole resistance, ESCR resistance,
A laminated sheet for thermoforming having water vapor transmission resistance and fragrance retention can be manufactured with good economy and moldability. Also,
In the method for producing a laminated sheet for thermoforming according to the present invention, the innermost layer of a hollow tube obtained by multilayer inflation molding of at least the resin material (i), the resin material (ii) and the resin material (iii) may be the same as the above. When the first layer is made of the resin material (i), workability is improved due to excellent anti-blocking property. In the method for producing a laminated sheet for thermoforming of the present invention, a hollow tube obtained by multilayer inflation molding of at least the resin material (i), the resin material (ii), and the resin material (iii) is sandwiched. If the laminated sheet for thermoforming has five or more layers, a thick sheet can be easily obtained, and it can be adapted to a product requiring more strength or deep drawing.

[Brief description of the drawings]

FIG. 1 is a graph showing an elution temperature-elution amount curve of (A1) linear low-density polyethylene in the present invention.

FIG. 2 is a graph showing an elution temperature-elution amount curve of an ethylene copolymer with a metallocene catalyst.

FIG. 3 is a graph showing an elution temperature-elution amount curve of (A2) linear low-density polyethylene in the present invention.

 ────────────────────────────────────────────────── ─── Continued on the front page F-term (reference) 4F100 AA05C AH08C AK04 AK04J AK05A AK05E AK06B AK06E AK08 AK08J AK63C AK63E AK65 AL01 AL05E AR00D BA03 BA04 BA05 BA07 BA10A BA10C BA10C JAE GBB16 BA26C12C JJ03 JK13 JK14 JL01 JL08C JL12 JL16E JN01 YY00A YY00C 4F207 AA04E AA05K AA07K AG01 AG03 AH54 AR15 AR17 KA01 KA19 KB26 KW41 KW45 4F208 AA04E AA05K AA07K AG01 AG03 AH54 AR15 AR17 LW02 LW26 LW45 MA01 MA02 MB01 MB22 MG04 MJ32 MW45 4J002 BB031 BB032 BB051 BB052 BB151 BB152 FD010 GF00 4J100 AA02P AA03Q AA04Q AA07Q AA16Q AA17Q AA19Q CA04 DA00 DA04 DA13 DA14 DA40 DA43 FA09 JA58 JA59

Claims (15)

[Claims] 1. A layer I made of a resin material (i) mainly composed of high-density polyethylene having a density of 0.93 g / cm ³ or more, and a resin material mainly composed of a high-pressure radical ethylene polymer ( ii) and a density of 0.94 g /
a laminated layer for thermoforming, comprising: a third layer made of a resin material (iii) containing a linear low-density polyethylene of cm ³ or less as a main component. 2. The thermoformed laminated sheet according to claim 1, wherein the laminated sheet is laminated in the order of the I-th layer, the II-th layer, and the III-th layer. 3. The thickness of the sheet is 50 μm to 5 mm, the thickness of the first layer is 10 μm to 1 mm, and the thickness of the second and third layers is 20 μm to 2 mm, respectively. The laminated sheet for thermoforming according to claim 1 or 2, wherein 4. The laminated sheet for thermoforming according to claim 1, further comprising a barrier layer (IV). 5. The resin material (i), the resin material (ii), and the resin material (I) obtained by recycling any one of the layer I, the layer II, and the layer III. (iii) a recycled resin layer (V) formed of or composed of the blended resin
The laminated sheet for thermoforming according to any one of claims 1 to 4, further comprising: 6. The laminated sheet for thermoforming according to claim 1, wherein the linear low-density polyethylene satisfies the following requirements (a) to (d). (A) a density of 0.86 to 0.94 g / cm ³ , (b) a melt flow rate of 0.01 to 50 g / 10
(C) a molecular weight distribution (Mw / Mn) of 1.5 to 4.5; (d) a total of 25 obtained from an integrated elution curve of an elution temperature-elution amount curve by a continuous heating elution fractionation method (TREF). The difference T ₇₅ -T ₂₅ and the density d between the temperature T _{25 at} which% elutes and the temperature T _{75 at} which 75% of the total elutes satisfy the following (Equation 1): (Equation 1) T ₇₅ -T ₂₅ ≦ -670 × d + 644 7. The thermoforming material according to claim 6, wherein the linear low-density polyethylene is (A1) a linear low-density polyethylene that further satisfies the following requirements (e) and (f). Laminated sheet. (E) orthodichlorobenzene (ODC) at 25 ° C.
B) The soluble content X (% by weight), the density d and the melt flow rate (MFR) satisfy the relationship of the following (Formula 2) and (Formula 3) (Formula 2) d−0.008 log MFR ≧ 0.93 X <2.0 (Equation 3) d−0.008 log MFR <0.93 X <9.8 × 10 ³ × (0.9300−d + 0.008)
(logMFR) ² +2.0 (f) Presence of multiple peaks in elution temperature-elution amount curve by continuous heating elution fractionation method (TREF) 8. The thermoforming material according to claim 6, wherein the linear low-density polyethylene is (A2) a linear low-density polyethylene that further satisfies the following requirements (g) and (h). Laminated sheet. (G) elution temperature by continuous Atsushi Nobori elution fractionation (TREF) - it is one peak of elution curve and the T ₇₅ -T ₂₅ and density d is, satisfy the relation of the following (Equation 4) ( (H) T ₇₅ −T ₂₅ ≧ −300 × d + 285 (h) One or two melting point peaks, and the highest melting point T _ml and density d satisfy the relationship of the following (Formula 5) ( Formula 5) T _ml ≧ 150 × d−17 9. The thermoforming laminated sheet according to claim 8, wherein the (A2) linear low-density polyethylene further satisfies the following requirement (i). (I) Melt tension (MT) and melt flow rate (MFR) satisfy the following (Equation 6) (Equation 6) logMT ≦ −0.572 × logMFR + 0.3 10. The linear low-density polyethylene is an organic cyclic compound having at least a conjugated double bond and an organic cyclic compound having at least a conjugated double bond.
The laminated sheet for thermoforming according to any one of claims 1 to 9, wherein the laminated sheet is produced in the presence of a catalyst containing a Group IV transition metal compound. 11. The additive compounded in the resin material (iii) is an additive which does not substantially migrate to the contacted object, or the additive is not compounded in the resin material (iii). The laminated sheet for thermoforming according to any one of claims 1 to 10. 12. The thermoforming laminated sheet according to claim 1, wherein the halogen concentration of the resin material (iii) is 10 ppm or less. 13. A method for producing a laminated sheet for thermoforming, comprising producing the laminated sheet for thermoforming according to claim 1 by multilayer inflation molding. 14. An innermost layer of a hollow tube obtained by multilayer inflation molding of at least the resin material (i), the resin material (ii), and the resin material (iii), is formed of a resin material (i). The method for producing a laminated sheet for thermoforming according to claim 13, wherein the laminated sheet is an I layer. 15. A hollow tube obtained by multilayer inflation molding of at least the resin material (i), the resin material (ii) and the resin material (iii), and
The method for producing a thermoformed laminated sheet according to claim 14, wherein the thermoformed laminated sheet has more than one layer.