JPH10168245A - Polyethylene resin composition for extruded laminate and extruded laminate product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition suitable for use as a sealant layer for food packaging materials and the like which has good sealing properties at a low temperature and a high heat seal strength, and also exhibits stable and good sealing properties over a wide range of temperature, and further is excellent in processability and has good slipping properties, by compounding two or more types of linear low density ethylene copolymer and two types of low density polyethylene. SOLUTION: A linear low density ethylene copolymer (A) used in this composition is a copolymer of ethylene and 3-20C α-olefin which is prepared using a metallocene catalyst, wherein a type of (A), hereinafter referred to as (A1), has a density (d) of 0.87 or less and a melt flow rate (MFR) of 0.1 to 40 and another type of (A), (An), has d of 0.87 or more and MFR of 0.1 to 40. A type of low density polyethylene (B), (B1), has d of 0.91 to O.93, MFR of 0.1 to 30 and a melt strength of 4g or more, and another type of (B), (B2), has d of 0.91 to 0.93, MFR of 0.1 to 30 and a melt strength of less than 4g. This composition comprises 50 to 99wt.% component (A) and 50 to 1wt.% component (B), and the weight ratios of A1/An and B1/B2 are 1/99 to 99/1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a polyethylene resin composition for extrusion lamination. More specifically, the linear low-density ethylene copolymer obtained by a polymerization method using a metallocene compound as a catalyst retains low-temperature sealability and high heat-sealing strength, and also has stable sealability over a wide range of temperatures, and extrusion lamination. The present invention relates to a polyethylene-based resin composition for extrusion lamination, which sometimes exhibits excellent workability and has good slipperiness, which is suitable for use in a sealant layer of a food packaging material or the like, and an extrusion-laminated product thereof.

[0002]

2. Description of the Related Art Conventionally, as a polyethylene resin or a resin composition for extrusion lamination for a sealant layer,
Low density polyethylene or ethylene-vinyl acetate copolymer has been used. In addition, a linear low-density polyethylene, and a resin in which an ethylene-propylene copolymer is blended with a linear low-density polyethylene are also used. However, these resins have the following advantages and disadvantages.

That is, although low-density polyethylene is excellent in processability, the polyethylene or ethylene-vinyl acetate copolymer has better sealing properties such as heat sealing strength and hot tack property than linear low-density polyethylene. Inferior. On the other hand, linear low-density polyethylene has poor processability at the time of extrusion lamination, and may be inferior in low-temperature sealability as compared with an ethylene-vinyl acetate copolymer.

As described above, these resins or resin compositions have, in addition to processability, strict characteristics particularly required for high-speed filling, for example, low-temperature sealability, high heat seal strength, and stability over a wide temperature range. It cannot be said that it is a suitable resin for extrusion lamination for a sealant layer satisfying well-balanced heat sealability and other filling suitability. In recent years, in view of the above situation, Japanese Patent Application Laid-Open No. 8-41254 discloses a method for improving the performance of an extrusion laminating resin for a sealant layer using a linear low-density polyethylene obtained by a polymerization method using a metallocene compound as a catalyst. And Japanese Patent Application Laid-Open No. 8-188681.

However, in these methods, by using the linear low-density polyethylene as a component of a resin composition for extrusion lamination for a sealant layer, the molecular weight distribution is narrow, and the copolymer composition distribution with respect to the molecular weight is narrow. Although there is a description of improvement in sealing properties such as low-temperature sealing properties, heat sealing strength, and hot tack properties utilizing the polymer properties originally caused by the molecular structure of the linear low-density polyethylene, the effect is substantially sufficient I can't say that
It cannot be said that there is a clear solution to the problem of extrusion lamination such as a large neck-in and a low drawdown property of the linear low-density polyethylene. In addition, there is no proposed method for improving slipperiness during filling.

That is, in these methods, it is difficult to simultaneously sufficiently satisfy important properties required for practical use of the extrusion laminating resin for the sealant layer, such as workability and slipperiness at the time of extrusion lamination, including sealing properties. I have to say that there is.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and exhibits low temperature sealability, high heat seal strength, and stable heat sealability over a wide temperature range. An object of the present invention is to provide a polyethylene resin composition for extrusion lamination, which is excellent in processability, has good slipperiness, and is suitable for use in a sealant layer for food packaging and the like, and an extrusion-laminated product thereof. is there.

[0008]

Means for Solving the Problems The present inventors have developed a polyethylene resin composition for extrusion lamination used for a sealant layer, which exhibits low-temperature sealing properties, high heat sealing strength, and heat sealing properties over a wide temperature range. As a result of intensive studies to develop a resin composition having excellent processability and good slipperiness, two types of linear low-density ethylene copolymers obtained by polymerizing with a metallocene compound as a catalyst are obtained. As used above, they have a specific density, a melt flow rate, and further have a specific density, a melt flow rate and a melt tension, for example, two types of low-density polyethylene obtained by a high-pressure radical polymerization method at a specific ratio. It was found that by blending and adding a heat stabilizer, a slip agent and an anti-blocking agent, it was suitable for that purpose. It has led to the present invention on the basis of.

That is, a first aspect of the present invention is a polyethylene resin composition comprising two or more linear low-density ethylene copolymers (An) and two types of low-density polyethylene (Bm). The linear low-density ethylene copolymer (An) is a copolymer composed of ethylene obtained by a polymerization method using a metallocene compound as a catalyst and an α-olefin having 3 to 20 carbon atoms. One of the chain low-density ethylene copolymers (An) (A1) has a density of 0.87 g / cm ³ or less and a melt flow rate of 0.1 to less.
At 40 g / 10 min, another type of linear low-density ethylene copolymer (An-A1) other than A1 has a density of 0.8
Greater than 7 g / cm ³ and a melt flow rate of 0.1 to
40 g / 10 min, and one of the two low-density polyethylenes (B1) has a density of 0.91 to 0.9.
3 g / cm ³ , melt flow rate 0.1-30 g /
10 min, with a melt tension of 4 g or more, another low-density polyethylene (B2) having a density of 0.91 to 0.93 g / c
m ³ , melt flow rate 1 to 30 g / 10 min, melt tension is less than 4 g, and the mixing ratio of An is 50
-99% by weight, Bm is 50-1% by weight, and the mixing ratio (weight ratio) of A1 and (An-A1)） A1 / (An
-A1) is 1/99 to 99/1, and the blending ratio (weight ratio) of B1 and B2 (B1 / B2) is 99/1 to 1/99.
And a polyethylene resin composition for extrusion lamination.

The second aspect of the present invention is that the total of An and Bm is 10
0.01 to 0.5 parts by weight of a heat stabilizer comprising a phenolic heat stabilizer and / or a phosphorus-based heat stabilizer, 0.01 to 0.2 parts by weight of a slip agent, antiblocking A polyethylene resin composition for extrusion lamination according to the first invention of the present invention, comprising 0.01 to 2 parts by weight of an agent.

A third aspect of the present invention is that the temperature dependency of the heat seal strength is 1.5 or less and the heat seal strength is 1.5 kg /
15 mm or more, the workability index at the time of lamination is 2 or more,
A laminate product having a polyethylene resin composition for extrusion lamination of the first or second invention of the present invention having a drawdown property of 80 m / min or more in a sealant layer. is there.

Hereinafter, the present invention will be described in detail. The linear low-density ethylene copolymer (An) used in the present invention is a random copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms obtained by a polymerization method using a metallocene compound as a catalyst. . The polymerization method using a metallocene compound as a catalyst refers to, for example, a polymerization method described in a republished patent of International Publication No. WO95 / 15985.

That is, the polymerization method using a metallocene compound as a catalyst comprises the following components (I), (II) and (III)
Is a polymerization method using a catalyst containing Ingredient (I)
Is at least one transition metal compound represented by the following formula (1).

[0014]

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In the formula (1), M is a transition metal selected from the group consisting of zirconium, titanium and hafnium, and R ¹ is a ligand having a cyclopentadienyl skeleton, nitrogen, phosphorus, A heterocyclic ligand having 1 to 4 carbon atoms containing arsenic, antimony or bismuth as a heteroatom, or a hetero tridentate ligand in which nitrogen, phosphorus or oxygen occupies a coordination site; Are each unsubstituted or substituted with an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an alkyl group having 1 to 20 carbon atoms with at least one aryl group having 6 to 20 carbon atoms. At least one selected from the group consisting of a substituted aralkyl group and an alkylaryl group in which an aryl group having 6 to 20 carbon atoms is substituted with at least one alkyl group having 1 to 20 carbon atoms. Wherein one substituent may replace at least two portions of the ligand, and the alkyl group may be linear, branched or cyclic; At least one may be bonded to the ligand via oxygen, nitrogen, sulfur or phosphorus, and at least one of the carbons constituting the substituent may be silicon.

R ² , R ³ and R ⁴ each independently represent a ligand having a cyclopentadienyl skeleton, nitrogen, phosphorus, arsenic, antimony or bismuth as a heteroatom having a heteroatom of 1-4 carbon atoms. Membered ligand, hetero tridentate ligand in which nitrogen, phosphorus or oxygen occupies a coordination site, having 1 to 20 carbon atoms
An alkyl group, an aryl group having 6 to 20 carbon atoms, and 1 carbon atom
-20 alkyl groups having at least one carbon atom having 6-20 carbon atoms
An aralkyl group substituted by an aryl group having 6 carbon atoms
-20 aryl groups have at least one carbon atom of 1-20
An alkylaryl group substituted with an alkyl group of the formula:
₃ R (R is unsubstituted or a hydrocarbon group having 1 to 8 carbon atoms substituted with at least one halogen),
A halogen atom or a hydrogen atom, in which an alkyl group is linear, branched or cyclic, and an alkyl group, an aryl group, an alkylaryl group, or an aralkyl group transitions via oxygen, nitrogen, sulfur, or phosphorus; A heteroatom ligand which binds to a metal may be formed, and at least one of carbons constituting an alkyl group, an aryl group, an alkylaryl group, and an aralkyl group may be silicon, and cyclopentadienyl A ligand having a skeleton, and a 5-membered heterocyclic ligand having 1 to 4 carbon atoms containing nitrogen, phosphorus, arsenic, antimony or bismuth as a hetero atom,
And hetero-3 in which nitrogen, phosphorus or oxygen occupy a coordination site
Each of the coordinating ligands is unsubstituted or an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms,
An aralkyl group in which an alkyl group having 1 to 20 carbon atoms is substituted with at least one aryl group having 6 to 20 carbon atoms,
And an aryl group having 6 to 20 carbon atoms is substituted with at least one substituent selected from the group consisting of an alkylaryl group substituted with at least one alkyl group having 1 to 20 carbon atoms. Substituents may substitute at least two moieties of the ligand, the alkyl group may be linear, branched or cyclic, and at least one of the substituents may be oxygen, nitrogen, sulfur or phosphorus. And at least one of the carbons constituting the substituent may be silicon.

A is an integer of 1 or more, b, c, d
Is an integer of 0 to 3, provided that a + b + c + d = 4
And each of R ¹ , R ² , R ³ and R ⁴ is a transition metal M
And R ⁰ is an alkylene group having 1 to 20 carbon atoms, an alkylene group having 1 to 20 carbon atoms, and an alkylene group having 1 to 20 carbon atoms, which binds one selected from R ² , R ³ and R ⁴ to R ^1. An alkylidene group, a silylene group, or a silylene group having 1 to 20 carbon atoms is an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and an alkyl group having 1 to 20 carbon atoms is at least one having 6 to 20 carbon atoms. An aralkyl group substituted with an aryl group,
And a substituted silylene group obtained by substituting an aryl group having 6 to 20 carbon atoms with at least one substituent selected from the group consisting of an alkylaryl group substituted with at least one alkyl group having 1 to 20 carbon atoms, And x is 0
Or 1. ｝ Component (II) is a finely divided inorganic solid (b-1) having a hydroxyl group on its surface,

[0018]

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In the formula (2), R ⁶ is a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms. The organoaluminum oxy compound (b-2) having an alkyloxyaluminum unit represented by｝ as a repeating unit is a supported inorganic solid component. Component (III) is an organoaluminum compound represented by the following formula (3) or (4)
It is represented by

[0020]

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In the formula (3), R ⁷ is an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 20 carbon atoms;
Is halogen or hydrogen, the alkyl group is linear,
It is branched or cyclic, and e is an integer of 1 to 3. ｝

[0022]

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[0023] {in formula (4), R ⁷ is the same as above, Y is ^eight -OR, -OSiR ⁹ ₃ group, -OAlR ¹⁰ ₂
Group, -NR ¹¹ ₂ group, -SiR ¹² ₃ group or -N (R ¹³⁾ A
a lR ¹⁴ ₂ group, e is a 1 or 2, R ^8,
R ⁹ , R ¹⁰ and R ¹⁴ each independently have 1 to 12 carbon atoms.
R ¹¹ is hydrogen, an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, a silyl group or at least one carbon atom having at least one carbon atom. A substituted silyl group substituted by an alkyl group having 1 to 12 carbon atoms; R ¹² and R ¹³ each independently represent an alkyl group having 1 to 12 carbon atoms; It is chain-like, branched or cyclic.直 鎖 The linear low-density ethylene copolymer (A
Examples of n) include a linear low-density ethylene-based copolymer obtained by a polymerization method using the above-mentioned metallocene compound as a catalyst, and The Dow Chemical C
o. / 1-octene copolymer (registered trademark A)
FFINITY and ENGAGE) by a polymerization method using a metallocene compound as a catalyst.

Linear low density ethylene copolymer (An)
Is a random copolymer of ethylene obtained by a polymerization method using a metallocene compound as a catalyst and an α-olefin having 3 to 20 carbon atoms, and having 3 to 20 carbon atoms used for copolymerization with ethylene. Examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene and 3-methyl- Examples thereof include 1-butene, 4-methyl-1-pentene, 6-methyl-1-heptene and the like.

Linear low density ethylene copolymer (An)
Is obtained by a polymerization method using a metallocene compound as a catalyst, and the linear low-density ethylene-based copolymer (A1) has a density of 0.8
7 g / cm ³ or less. Further, the melt flow rate is 0.1 to 40 g / 10 min. Preferably it is 0.5 to 30 g / 10 min. The linear low-density ethylene copolymer having such properties has a melting behavior,
It has good melt flow behavior and is suitable for exhibiting low-temperature sealability, high heat seal strength, and stable sealability over a wide temperature range.

Linear low density ethylene copolymer (A1)
Linear low-density ethylene copolymer excluding (An-A1)
Has a density of more than 0.87 g / cm ³ , preferably
88 to 0.94 g / cm ³ , the melt flow rate is
0.1-40 g / 10 min, preferably 0.5-30
It is sufficient that each has a different density and a different melt flow rate in the range of g / 10 min.
It is preferably an integer of 5, more preferably 1 to
3.

The density was measured at a melt flow rate of 190 ° C. under a load of 2.16 kg. The strand was boiled with hot water for 1 hour, cooled at 23 ° C. for 1 hour, and then cooled with a density gradient tube. Measured. The melt flow rate is 190 ° C., 2.16 according to ASTM D-1238.
It is measured under the condition of a kg load. The low-density polyethylene (Bm) in the present invention can be obtained by a known method, for example, a high-pressure radical polymerization method. m is an integer of 1 or 2.

Bm has a density of 0.91 to 0.93 g / c.
m ³ , preferably 0.91 to 0.92 g / cm ³ .
The melt flow rate is 0.1 to 10 g / 10 min, preferably 0.3 to 5 g / 10 min, and the melt tension is 4 g.
That is all. Low-density polyethylene having such properties exhibits a great effect in improving neck-in during extrusion lamination.

The melt tension is measured as a take-up tension when a melted strand extruded at the time of measuring a melt flow rate under a condition of 190 ° C. and a load of 2.16 kg is taken up at a speed of 785 cm / min. The density and melt flow rate of the low-density polyethylene are measured by the same methods as described above. The low-density polyethylene (B2) in the present invention can be obtained by a known method, for example, a high-pressure radical polymerization method, similarly to the low-density polyethylene (B1), and has a density of 0.91 to 0.93 g / cm ³ , Preferably it is 0.91 to 0.92 g / cm ³ . Mel flow rate is 1 to 30 g / 10 min, preferably 1 to 20 g
g / 10 min, the melt tension is less than 4 g, preferably 3 g
g or less. Low-density polyethylene having such properties is very effective in improving drawdown properties during extrusion lamination.

The low density polyethylene (B1), (B
2) may be a copolymer with another α-olefin, vinyl acetate, acrylate, or the like as long as the object of the present invention is not impaired. The first polyethylene resin composition for extrusion lamination of the present invention has a compounding ratio of A
n 50 to 99% by weight, preferably 70 to 95% by weight, B
m is 50 to 1% by weight, preferably 30 to 5% by weight.
When An is less than the above range, low-temperature heat sealability,
The sealing strength may decrease. On the other hand, if Bm is less than the above range, the effect of improving neck-in and drawdown properties may be insufficient.

The mixing ratio (weight ratio) of A1 and (An-A1) {A1 / (An-A1)} is 1/99 to 99/1,
Preferably it is 5/95 to 90/10. If A1 is less than the above range, low-temperature sealing properties and stable sealing properties over a wide temperature range may not be exhibited. B
The mixing ratio (weight ratio) (B1 / B2) of 1 and B2 is 99 /
It is 1/1/99, preferably 90/10 to 10/90. If B1 is less than the above range, the effect of improving neck-in may be insufficient.

The second polyethylene resin composition for extrusion lamination according to the present invention comprises a heat stabilizer comprising a phenol heat stabilizer and / or a phosphorus heat stabilizer based on 100 parts by weight of the total of An and Bm. 0.01 to 0.5 part by weight, preferably 0.01 to 0.4 part by weight, and 0.01 to 0.2 part by weight of the slip agent, preferably 0.01 to 0.1 part by weight.
5 parts by weight, 0.01 to 2 parts by weight of an antiblocking agent,
Preferably, it is necessary to contain 0.01 to 1.5 parts by weight.

Here, the phenolic heat stabilizer includes:
2,6-di-t-butyl-4-methylphenol (dibutylhydroxytoluene), n-octadecyl-3-
(4-hydroxy-3,5-di-t-butylphenyl) propionate, tetrakis (methylene (3,5-di-t-
-Butyl-4-hydroxyhydrocinnamate)) Tetrakis (2,4-
Di-t-butylphenyl) -4,4'-biphenylene-
Di-phosphonite and the like, slip agents include erucic acid amide, oleic acid amide, stearic acid amide, ethylene bistearic acid amide and the like, and anti-blocking agents include sodium calcium aluminosilicate and diatomaceous earth.

If the amount of the phenolic heat stabilizer and / or the amount of the phosphorus heat stabilizer is less than the above range, the resin undergoes thermal degradation during extrusion, which may impair the melt flow characteristics and lower the sealing performance. If the amount is larger than the above range, a problem such as discoloration may occur. If the amount of the slip agent or the anti-blocking agent is less than the above range, the slip property at the time of filling may be impaired, and stable operation may not be performed. On the other hand, if it exceeds the above range, the sealing performance may be reduced.

Such a polyethylene resin composition for extrusion lamination of the present invention can be produced by using a known method. For example, a linear low-density ethylene-based copolymer (An) and a low-density polyethylene (Bm) and additives such as a phenol-based heat stabilizer, a phosphorus-based heat stabilizer, a slip agent, and an anti-blocking agent are added to a single screw extruder. It can be obtained by melt-kneading using a twin-screw extruder or a kneader. The above additives can be blended with low-density polyethylene, melt-kneaded with a twin-screw extruder, granulated, and added as a master batch (C). Moreover, it can also be obtained by these dry blends.

The third, extruded laminate of the present invention is:
The temperature dependence of the heat seal strength of the polyethylene resin composition for extrusion lamination forming a sealant layer is as follows:
5 or less, heat seal strength is 1.5 kg / 15 mm or more, workability index at extrusion lamination is 2 or more, and drawdown property is 80 m / min or more. The temperature dependency of the heat seal strength is obtained by multiplying a value obtained by dividing a difference between a heat seal strength to be described later and a peel strength at a seal temperature of 90 ° C. by a difference between the complete heat seal temperature and 90 ° C. by 10. The numerical value indicates the temperature dependence of the peel strength in the temperature region until the heat seal is completely performed, and indicates the stability of the heat sealability. If the temperature dependency of the heat seal strength is more than 1.5, stable heat sealability may not be easily obtained with respect to a change in the sealing temperature at the time of filling, and the pressure resistance of the filling bag may be reduced. Further, even if the temperature dependency of the heat seal strength is 1.5 or less, if the heat seal strength is less than 1.5 kg / 15 mm, practical use may be difficult.

The workability index refers to the drawdown property described later and the neck-in (winding speed 60 m / mi) described later.
n) represents the productivity obtained during extrusion lamination. For example, a large workability index means that the drawdown property is large and an extruded laminate can be produced at a higher speed, and / or the neck-in is small and the amount of resin in the ear portion to be discarded by trimming is small. . When the processability index is less than 2, even if the low-temperature heat sealability and the seal strength are excellent, the productivity of the extrusion lamination process is lowered, and it is not economical. Further, even if the workability index is 2 or more, if the drawdown property is less than 80 m / min,
Even if excellent sealing properties are obtained, productivity is low and it is not suitable.

The extruded laminate according to the present invention can use cellophane, nylon, polyethylene terephthalate, polypropylene, polyvinyl alcohol, aluminum foil, kraft paper, etc. alone or in combination of two or more as a substrate. These substrates can be used as they are, but may be coated with a polyvinylidene chloride coat, so-called K coat.

Further, a low density polyethylene, a linear low density polyethylene or a linear low density polyethylene obtained by polymerization using a metallocene compound as a catalyst as a sand layer on the above-mentioned substrate is directly or ozone-treated. The laminated material may be used as a substrate. The extruded laminate according to the present invention can be obtained by extruding and laminating the polyethylene resin composition for extrusion lamination on the above-mentioned substrate by a known method.

[0040]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described more specifically based on embodiments. In addition, the polymer used, the extrusion lamination method, and the physical property measurement method are as follows. (1) Linear low-density ethylene copolymer (An); an ethylene / 1-octene copolymer was used. The catalyst comprising the metallocene compound used for the polymerization for obtaining the copolymer is (n-butylcyclopentadienyl) zirconium chloride or ethylenebis (indenyl) zirconium dichloride. Methylaluminoxane supported on silica and triisobutylaluminum as an organoaluminum compound were used. The amount ratio of the metallocene compound to the organic aluminum oxy compound is 1: 500 (molar ratio) in terms of zirconium and aluminum, and the amount ratio of the organic aluminum oxime compound and the organic aluminum compound is 63:37 (molar ratio) in terms of aluminum. did.

Preparation of catalyst Toluene was used as a solvent for supporting methylaluminoxane on porous silica. The polymerization was carried out at a temperature of 70 ° C. and a pressure of 7 kg / cm ² G. Linear low-density ethylene copolymer (A1) and A1
Linear low-density ethylene copolymer excluding (An-A1)
Was obtained by changing the density and the melt flow rate in the above polymerization method depending on the amount of 1-octene, or the type of silica, the type and amount of the metallocene compound, and some conditions such as the polymerization temperature.

In Examples and Comparative Examples, a linear low-density ethylene copolymer (A1) was prepared by using ethylene / 1-
Octene copolymer (The Dow Chemical)
Co. (Registered trademark ENGAGE, EG8200), A
Linear low-density ethylene-based copolymer (An-A
1) An ethylene / 1-octene copolymer (TheD
ow Chemical Co. Made, registered trademark AFFI
NITY, PT1450, same, HM1100, same, SM
1300) was also used. (2) Low-density polyethylene (B1) and low-density polyethylene (B2); those obtained by a high-pressure radical polymerization method were used. (3) Masterbatch (C): n-octadecyl-3- (4-hydroxy-3,5-) as a phenolic heat stabilizer
Di-t-butylphenyl) propionate, tetrakis (2,4-di-t-butylphenyl) -4,4′-biphenylene-di-phosphonite as a phosphorus-based heat stabilizer,
Erucamide as a slip agent and sodium calcium aluminosilicate as an antiblocking agent were mixed with low-density polyethylene and granulated by melt-kneading with a twin-screw extruder. (4) Extrusion lamination method: A single-screw extruder equipped with a straight manifold type as a die was used, and the lip width was set to 400 mm and the lip clearance was set to 0.7 mm. The resin was extruded at a resin temperature of 300 ° C., and was laminated on a substrate fed from a feeder through an air gap of 140 mm. Thereafter, the laminate was cooled by a cooling roll of a semi-mirror specification, and the laminate was wound around a winder.

The substrate used was prepared by treating ONy (25 μm) with an anchoring agent and then obtaining a density of 0.923 g / c by the above method.
A material obtained by previously laminating a low-density polyethylene having a m ^{3 of} 4.0 and a melt flow rate of 4.0 to a thickness of 20 μm was used. (5) Physical property measurement method; Neck-in: Except for using a kraft paper having a corona treatment of 2 kw as a substrate in the above-mentioned extrusion lamination method, the same method was used.
The winding speed was increased from 60 m / min to 120 m / min while fixing the discharge amount to give a laminate thickness of μm. The sum of the neck-in distances of both ears at that time was defined as neck-in (mm). Drawdown property: At the time of neck-in measurement, the rate at which surging was started when the winding speed was further increased or the rate at which the film was cut was evaluated as drawdown property (m / min). Workability index during extrusion lamination: The value obtained by dividing the drawdown property (m / min) by the neck-in (mm) at a winding speed of 60 m / min was taken as the workability index during extrusion lamination. Heat seal strength: The laminated product obtained by the extrusion laminating method is heated with a heat sealer (manufactured by Tester Sangyo Co., Ltd.) at a sealing pressure of 2 kg / cm ² and a sealing time of 1 second while increasing the sealing temperature from 80 ° C. by 10 ° C. each. And heat sealed. The peel strength of the seal was measured using a tensile tester (manufactured by Orientec) at a tensile speed of 500 mm / m.
The value measured when the peel strength reached equilibrium was defined as the heat seal strength. Low-temperature heat-sealability: The temperature at which the above-mentioned heat-sealing strength was obtained was taken as the complete heat-seal temperature and used as a measure of low-temperature heat-sealability. Temperature dependency of heat seal strength: A value obtained by dividing the difference between the above-mentioned heat seal strength and the peel strength at a seal temperature of 90 ° C. by the difference between the complete heat seal temperature and 100 ° C. and multiplying by 10 The temperature dependency of the heat seal strength was determined. In addition, when it is not sealed at 90 ° C., the peel strength is set to 0 kg / 15 mm. Slipperiness: Measurement was performed using the laminate obtained by the extrusion lamination method. Using a sliding angle tester (manufactured by Toyo Seiki Seisaku-sho, Ltd.), a metal indenter whose weight was adjusted to a surface pressure of 7.6 g / cm ² was placed on the sealant layer of the laminated product, and the inclination angle was gradually increased. The angle at which the indenter began to slide was measured as a slip angle to evaluate the slipperiness.

[0044]

EXAMPLE 1 One (A1) of two or more linear low-density ethylene copolymers was an ethylene / 1-octene copolymer obtained by the above polymerization method and had a density of 0.868 g.
/ Cm ³ and a melt flow rate of 5.1 g / 10 min. As the linear low-density ethylene-based copolymer (An-A1) excluding A1, the ethylene / 1-octene copolymer (A2) obtained by the above polymerization method, a density of 0.902
g / cm ³ , melt flow rate 8.1 g / 10 min
Was used.

The low-density polyethylene (B1) has a density of 0.918 g / cm ³ and a melt flow rate of 2.0 g.
The low density polyethylene (B2) has a density of 0.916 g / cm ³ , a melt flow rate of 4.2 g / 10 min, and a melt tension of 3.5 g. 80% by weight of An and 20% by weight of Bm
And the mixing ratio (weight ratio) of A1 / (An-A1) is 2
5/75, the blending ratio (weight ratio) of (B1 / B2) is 75
/ 25.

Further, a master batch (C) is blended,
After dry blending, granulation was performed by melt-kneading with a single screw extruder. In the obtained polyethylene resin composition, 2000 ppm of n-octadecyl-3- (4-hydroxy-3,5-di-tert-butylphenyl) propionate and tetrakis (2,4-di-tert-) were used as additives.
Butylphenyl) -4,4'-biphenylene-di-phosphonite at 1000 ppm and erucamide at 500 ppm.
ppm, sodium calcium aluminosilicate 3000
ppm, respectively. Using the obtained polyethylene-based resin composition, extrusion lamination was performed by the above-described method, the workability was evaluated, and the obtained laminate was used for heat sealing strength, low-temperature sealing,
The slip property was evaluated. Table 1 shows the resin composition, Table 2 shows the processability,
Heat seal strength, low temperature heat sealability, temperature dependence of heat seal strength, and slipperiness were exhibited.

[0047]

Examples 2 and 3 A linear low-density ethylene copolymer (A
Except for changing the density and the melt flow rate of 2), granulation and extrusion coating were performed in the same manner as in Example 1, and the workability was evaluated, and the heat seal strength and slipperiness were evaluated using the obtained laminate. did. Table 1 shows the resin composition, and Table 2 shows the workability, heat seal strength, low-temperature heat sealability, temperature dependency of heat seal strength, and slipperiness, together with Example 1.

[0048]

Example 4 Linear low-density ethylene copolymer (A1)
As The Dow Chemical Co. ENGAGE, EG8200 (ethylene / 1
-Octene copolymer) and as a linear low-density ethylene-based copolymer (A2), The Dow Chemical.
al Co. Trademark AFFINITY, PT14
50 (ethylene / 1-octene copolymer) was used. Except for this, extrusion lamination was carried out in the same manner as in Example 1, and the processability was evaluated, and the heat seal strength, low temperature sealability, and slipperiness were evaluated using the obtained laminate. Table 1 shows the resin composition, and Table 2 shows workability, heat seal strength, low temperature heat sealability, temperature dependency of heat seal strength, and slipperiness.

[0049]

Example 5 Linear low-density ethylene copolymer (A2)
As The Dow Chemical Co. Extrusion lamination was performed in the same manner as in Example 4 except that AFFINITY and HM1100 (ethylene / 1-octene copolymer) were used, and the processability, heat seal strength of the laminated product, and low-temperature sealability were used. And the slipperiness was evaluated. Table 1 shows the resin composition, and Table 2 shows workability, heat seal strength, low temperature heat sealability, temperature dependency of heat seal strength, and slipperiness.

[0050]

Examples 6 and 7 The same procedure as in Example 4 except that the linear low-density ethylene copolymer (A3) was used as The Dow.
Chemical Co. AFFINIT registered trademark
Y, SM1300 (ethylene / 1-octene copolymer)
And the mixing ratio of An and Bm, A1 / (An-A1)
Extrusion lamination was performed in the same manner as in Example 4 by changing the blending ratio (weight ratio) of B1 / B2 and the blending ratio (weight ratio) of B1 / B2, and the processability, heat seal strength of the laminated product, low-temperature sealability, The slip property was evaluated. Table 1 shows the resin composition, and Table 2 shows workability, heat seal strength, low temperature heat sealability, temperature dependency of heat seal strength, and slipperiness.

[0051]

[Table 1]

[0052]

[Table 2]

As is evident from Tables 1 and 2, the polyethylene resin composition for extrusion lamination of the present invention comprises:
Excellent workability during extrusion coating, such as neck-in and draw-down properties, while exhibiting low-temperature heat-sealing properties, high heat-sealing strength, and stable heat-sealing properties, with good slipperiness, and extrusion used for sealant layers It turns out that it is suitable as a resin composition for coating.

[0054]

Comparative Examples 1-4 The resin composition of the polyethylene resin composition used is shown in Table 3, and its workability, heat seal strength, low temperature heat seal property, temperature dependence of heat seal strength, and slip property are shown in Table 4, respectively. It is shown together.

[0055]

Comparative Examples 5 to 7 Linear low-density ethylene copolymer (A
As 1), The Dow Chemical C
o. ENGAGE, EG8200 (ethylene / 1-octene copolymer) manufactured by FUJIFILM Corporation. One type of linear low-density ethylene copolymer excluding A1 (An-A1)
Is A2 as The Dow Chemical C
o. Trade name AFFINITY, PT1450 (ethylene / 1-octene copolymer), and The DowC as a linear low-density ethylene copolymer A3.
chemical Co. AFFINIT registered trademark
Y, SM1300 (ethylene / 1-octene copolymer)
Was used. Table 3 shows the resin composition of the polyethylene resin composition, and Table 4 shows the processability, heat seal strength, low temperature heat sealability, temperature dependency of heat seal strength, and slipperiness.

[0056]

[Table 3]

[0057]

[Table 4]

[0058]

The polyethylene resin composition for extrusion lamination of the present invention has a neck-in,
Extrusion coating resin used for the sealant layer, with excellent workability during extrusion lamination such as drawdown properties, low temperature heat sealability, high heat seal strength, stable heat sealability, and good slipperiness. It is suitable as a composition.

The extruded laminate product of the present invention using the resin for the sealant layer has high productivity, high-speed filling due to the combined low-temperature heat-sealing properties, high heat-sealing strength, stable heat-sealing properties, and good slipperiness. It is excellent in suitability and can be suitably used as a packaging material for foods such as liquid soup, water, paste, livestock meat and processed meat products.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 23/08 C08L 23/08

Claims (3)

[Claims] 1. Two or more linear low-density ethylene copolymers (An) and two low-density polyethylenes (Bm)
Wherein the linear low-density ethylene-based copolymer (An) is obtained by a polymerization method using a metallocene compound as a catalyst.
A copolymer comprising α-olefins of from 20 to 20
One (A1) of the linear low-density ethylene copolymers (An) of at least one kind has a density of 0.87 g / cm ³ or less;
A at a melt flow rate of 0.1 to 40 g / 10 min.
Other types of linear low-density ethylene copolymers (An-A1) other than 1 have a density of more than 0.87 g / cm ³ and a melt flow rate of 0.1 to 40 g / 10 min. One of the low-density polyethylenes (B1) has a density of 0.91 to 0.93 g / cm ³ , a melt flow rate of 0.1 to 30 g / 10 min, a melt tension of 4 g or more, and another low-density polyethylene Polyethylene (B2)
Has a density of 0.91 to 0.93 g / cm ³ , a melt flow rate of 1 to 30 g / 10 min, and a melt tension of less than 4 g.
Is 50 to 1% by weight, and the mixing ratio (weight ratio) of A1 and (An-A1) {A1 / (An-A1)} is 1/99.
~ 99/1, the mixing ratio (weight ratio) of B1 and B2 (B
1 / B2) is from 99/1 to 1/99, which is a polyethylene resin composition for extrusion lamination. 2. 0.01 to 0.5 part by weight of a heat stabilizer comprising a phenolic heat stabilizer and / or a phosphorus heat stabilizer and 100% by weight of a total of An and Bm, and a slip agent 0 2. The polyethylene resin composition for extrusion lamination according to claim 1, comprising 0.01 to 0.2 parts by weight and 0.01 to 2 parts by weight of an antiblocking agent. 3. The temperature dependency of the heat seal strength is 1.5.
The polyethylene resin composition for extrusion lamination according to claim 1 or 2, wherein a heat seal strength is 1.5 kg / 15 mm or more, a workability index at the time of lamination is 2 or more, and a drawdown property is 80 m / min or more. An extruded laminate product having an object in a sealant layer.