JPH072875B2 - Modified linear low density polyethylene composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel modified linear low density polyethylene composition having improved adhesive performance at high temperatures.

BACKGROUND OF THE INVENTION Linear low-density polyethylene is a thermoplastic resin that is excellent in various properties such as thermal stability, chemical resistance, moldability and weather resistance, and is a hollow molding product, injection molding product, film, fiber and Widely used as a laminated film for food packaging. For example, a laminated film used for food packaging or the like has an α of 3 to 4 carbon atoms.
A laminated film of a linear low density polyethylene copolymerized with an olefin and a polymer compound such as nylon is used. In the case of such a laminated film, since the adhesiveness of the linear low-density polyethylene to a high molecular compound such as nylon is poor, a linear low-density polyethylene graft-polymerized with a polar substance such as maleic anhydride, or A material to which an adhesive component such as a rubber-like substance is added is used.

Recently, a laminated film using the linear low-density polyethylene as described above has been used as a retort food or a simple retort food (hereinafter, both are collectively referred to as "retort food" in the present invention).
It is often used for packaging, etc.).

Retort pouch foods are generally made into a bag by heat-pressing the bottom part of a laminated film that is formed by stacking a linear low-density polyethylene layer on the inside and a nylon layer on the outside so that a cylindrical layer is formed. After filling the contents, the inlet is heated and pressure-bonded to seal it, and then put in a pressure cooker etc. in this state for heat sterilization (120 for retort food).
Approximately ℃, in the case of simple retort food, heat sterilization with heated water with a concentration of around 100 ℃) is packaged and sterilized to become a product. Therefore, the laminated film used for such packaging needs to have good heat resistance as well as good adhesive strength even at high temperatures. Further, apart from such heat resistance and adhesiveness at high temperature, as a unique property required as a laminated film for packaging of retort foods, the pressure-bonded heated portion does not peel off due to contact with heated water during heat sterilization. (It has excellent resistance to hot water). Considering the method of heat sterilization, as a laminated film for packaging of retort food, it is usually at least 30 in hot water under pressure of 100 ℃ or more. It is necessary to have a heat-resistant water-bonding property such that the thermocompression-bonded portion does not peel off even after contact for a minute.

When forming a laminated film using linear low-density polyethylene, a composition obtained by adding a rubber-like substance to a modified product obtained by graft-polymerizing an α, β-unsaturated carboxylic acid component such as maleic anhydride is used. It is said that this can be done (see, for example, Japanese Patent Publication No. 60-11056).

This composition has a property that it can be used for packaging retort foods by containing a modified substance of linear low density polyethylene and a rubber-like substance, but since it contains a rubber-like substance, a laminated film is produced. It was found that there is a problem that blocking easily occurs at that time. Therefore, when a laminated film is produced using this composition, there is a problem that it is necessary to add a special improvement to the apparatus so as to prevent the films from sticking to each other, or to add an anti-blocking agent.

Therefore, the present inventor has a linear low-density polyethylene having thermocompression bonding that can be advantageously used for packaging of retort foods while maintaining the excellent properties of the linear low-density polyethylene without adding a rubber-like substance. As a result of studying the composition, first, the linear low-density polyethylene serving as the base has an α-olefin having a carbon number of 5 to 10 as compared with the conventionally used α-olefin having a carbon number of 3 to 4. The linear low-density polyethylene formed by copolymerization has excellent heat resistance and is superior to the linear low-density polyethylene that has been conventionally used for heating at high temperature such as packaging of retort foods. Found out. Further, it has been found that this linear low-density polyethylene is equal to or more than the conventional one in other characteristics such as moldability which the linear low-density polyethylene essentially has.

Then, the present inventors have proposed a method for imparting adhesiveness to a linear low-density polyethylene formed by copolymerizing α-olefin having a larger number of carbon atoms than the above-mentioned conventional one, while maintaining its excellent properties. Initially, an attempt was made to modify the linear low-density polyethylene by graft-polymerizing an α, β-unsaturated carboxylic acid modifier and using the modified product as an adhesive component.

However, in the usual method, as the carbon number of the α-olefin increases, the grafting efficiency of the α, β-unsaturated carboxylic acid modifier tends to decrease, and the α-olefin having a large number of carbon atoms is copolymerized. It was difficult to produce a modified product having sufficient adhesiveness using the linear low density polyethylene. Furthermore, when modification is performed at a high concentration by increasing the addition amount of the α, β-unsaturated carboxylic acid modifier, the decomposition reaction of the linear low density polyethylene proceeds and a modified product having the desired properties is prepared. It was difficult to do. That is, it is difficult to produce an α, β-unsaturated carboxylic acid modified product of a linear low-density polyethylene having the property that good adhesiveness can be imparted to the composition by a conventional method. It was not possible to use it. It was also attempted to use a linear low-density polyethylene-modified product obtained by graft-polymerizing the α, β-unsaturated carboxylic acid-modified component at a low concentration alone, but this product has sufficient adhesiveness even under normal conditions. It turned out not to be.

[Object of the Invention] An object of the present invention is to provide a novel adhesive modified linear low density polyethylene composition having improved adhesive performance at high temperatures.

More specifically, the present invention provides a modified linear low-density polyethylene composition having both good adhesive strength at high temperature and good hot water adhesive strength while maintaining the properties inherently possessed by linear low-density polyethylene. The purpose is to

SUMMARY OF THE INVENTION The present invention relates to a linear low-density polyethylene I containing a repeating unit derived from an α-olefin I having 5 to 10 carbon atoms and / or an α, β-unsaturated carboxylic acid modified product thereof, and a carbon. A linear low density polyethylene II containing a repeating unit derived from α-olefin II of the formula 3 or 4 and an α, β-unsaturated carboxylic acid modified product thereof in a weight ratio within the range of 60:40 to 99: 1. A modified linear low-density polyethylene composition characterized by containing the above.

[Effect of the Invention] The modified linear low-density polyethylene composition of the present invention is prepared by selecting the α, β-unsaturated carboxylic acid modified product of the linear low-density polyethylene II (second component) as an adhesive component. In addition to exhibiting good adhesion performance, the addition of this second component has excellent heat resistance, moldability, thermal stability, chemical resistance and weather resistance of the linear low density polyethylene I (first component). The characteristics are not impaired.

Further, the composition of the present invention does not peel off even when the thermocompression-bonded portion is in contact with the heated water for a long time, and exhibits excellent hot water adhesiveness.

Furthermore, the good adhesive performance of the composition of the present invention is remarkably exhibited especially at high temperatures, and the adhesive strength at 100 ° C., which is markedly reduced when based on ordinary linear low density polyethylene, is Less susceptible to temperature than

DETAILED DESCRIPTION OF THE INVENTION The modified linear low-density polyethylene composition of the present invention comprises a linear low-density polyethylene I or a linear low-density polyethylene I containing a repeating unit derived from an α-olefin having 5 to 10 carbon atoms as a first component. α, β-unsaturated carboxylic acid modified product, and α, β-unsaturated carboxylic acid modified linear low density polyethylene II containing a repeating unit derived from an α-olefin having 3 or 4 carbon atoms as a second component An object is contained in a specific weight ratio.

The first component, linear low-density polyethylene I, is a linear low-density polyethylene I containing a repeating unit derived from ethylene and an α-olefin having 5 to 10 carbon atoms (preferably having 6 to 8 carbon atoms). The α-olefin I constituting the linear low density polyethylene may be linear or branched. Examples of such α-olefin I include pentene-1, hexene-1, 4-methyl-
Mention may be made of pentene-1 and octene-1.

The repeating unit derived from such an α-olefin I is usually contained in the linear low density polyethylene I in an amount of 0.1 to 10 mol%.
The content is within the range (preferably 1 to 5 mol%). The repeating unit derived from α-olefin I may be contained in the linear low density polyethylene I either alone or in combination of two or more.

The linear low density polyethylene I containing repeating units derived from this α-olefin I usually has a melt index in the range of 0.1 to 10 g / 10 min (preferably 1 to 6 g / 10 min) and a density of 0.91 to 0.94 g / cm ³ (preferably 0.91
It is a linear low-density polyethylene in the range of up to 0.93 g / cm ³ . Further, the melting point of this linear low density polyethylene I is usually within the range of 115 to 130 ° C.

Such a linear low-density polyethylene production method is already known, and a product produced by the known method can also be used in the present invention.

The first component of the present invention may be an α, β-unsaturated carboxylic acid modified product of this linear low density polyethylene I, in addition to the above linear low density polyethylene I. And a linear low density polyethylene I.

However, according to the study by the present inventor, as the carbon number of the α-olefin constituting the linear low-density polyethylene I increases, the α, β-unsaturated carboxylic acid modifier tends to be less likely to undergo graft polymerization. When modified to a high concentration, it becomes difficult to maintain the characteristics of the linear low-density polyethylene I. Therefore, as this α, β-unsaturated carboxylic acid modified product, 1 g of the linear low-density polyethylene I is usually used. On the other hand, a modified product in which an α, β-unsaturated carboxylic acid modifying component of 0.1 × 10 ⁻⁴ mol or less is graft-polymerized is used. α, β
-When the graft amount of the unsaturated carboxylic acid-modified component is too large, the properties such as heat resistance may deteriorate, and further the melt index decreases and the gel content increases, so that the moldability of the obtained composition decreases. I have something to do.

The melt index of the α, β-unsaturated carboxylic acid modified product tends to be somewhat lower than the melt index of the linear low-density polyethylene I used as the base, but it is usually within the above range. Further, since the density and melting point do not change significantly by the above-mentioned low-concentration modification, the density and melting point of the modified product are usually within the same range as that of the linear low-density polyethylene I described above.

The modifier used for producing the α, β-unsaturated carboxylic acid modified product of the linear low-density polyethylene I is used when producing the α, β-unsaturated carboxylic acid modified product of the linear low-density polyethylene II described later. The denaturing agent used for can be used, and the production can be performed in the same manner.

The linear low-density polyethylene I includes ethylene and α
-In addition to the repeating unit derived from olefin I, other monomer components may be contained within a range that does not impair the properties thereof.

This first component allows the composition of the present invention to have good heat resistance.

The second component of the modified linear low density polyethylene composition of the present invention is α of linear low density polyethylene II containing repeating units derived from α-olefin II having 3 or 4 carbon atoms,
It is a β-unsaturated carboxylic acid modified product.

Α-Olefin II which constitutes linear low density polyethylene II
Is one having 3 or 4 carbon atoms. Therefore, the α-olefin II is propylene and butene-1. The linear low-density polyethylene II may contain repeating units derived from α-olefin II alone or may contain two kinds of repeating units. It is preferred that the α-olefin II is butene-1. Repeating units derived from such α-olefins II are linear low density polyethylene II
The content is usually contained in the range of 0.1 to 10 mol% (preferably 1 to 5 mol%).

A linear low density polyethylene II containing repeating units derived from such an α-olefin II usually has a melt index in the range of 0.1 to 20 g / 10 min (preferably 1 to 10 g / 10 min), and A linear low density polyethylene having a density within the range of 0.90 to 0.95 g / cm ³ (preferably 0.91 to 0.93 g / cm ³ ). Furthermore, the melting point of such linear low density polyethylene II is usually in the range of 115 to 130 ° C.

Such a linear low-density polyethylene production method is already known, and a product produced by the known method can also be used in the present invention.

The second component of the composition of the present invention is a modified product of the linear low-density polyethylene II modified with α, β-unsaturated carboxylic acid, and the α, β-unsaturated carboxylic acid modifier used for this modification is As examples, mention may be made of acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid and their possible acid anhydrides, and their derivatives. Two or more modifiers may be used. Among these, maleic acid or maleic anhydride is preferably used as the α, β-unsaturated carboxylic acid modifier.

The second component is usually 1 g of the linear low density polyethylene II above.
On the other hand, it is a modified product in which an amount of the α, β-unsaturated carboxylic acid modifying component in the range of 0.1 × 10 ^{−4 to} 5 × 10 ⁻⁴ mol is graft-polymerized. Further, a modified product in which an amount of α, β-unsaturated carboxylic acid-modifying component in the range of 0.1 × 10 ^{-4 to} 4.5 × 10 ^-4 mol is graft-polymerized is preferable, and among these, particularly, 0.
A modified product in which an α, β-unsaturated carboxylic acid-modified component in an amount within the range of 5 × 10 ⁻⁴ × 2.0 × 10 ⁻⁴ mol is graft-polymerized is preferable. Since this modified product mainly imparts adhesiveness to the composition of the present invention, the adhesive strength of the obtained composition may be insufficient when the graft amount is small, and
When a modified product having an excessively large graft amount is used, it may gel during the graft polymerization reaction and the melt index may decrease, so that the moldability of the resulting composition may decrease.

The melt index of the α, β-unsaturated carboxylic acid modified product of this linear low-density polyethylene II is usually in the range of 0.1 to 20 g / 10 minutes (preferably 0.1 to 10 g / 10 minutes), and the density is usually 0.90 to 0.95 g / cm ³ (preferably 0.91~0.93g / cm ³⁾ is within the range of the melting point is in the range of usually 115 to 130 ° C..

In addition, linear low-density polyethylene II is α-olefin II
In addition to the repeating unit derived from, other monomer components may be contained within a range that does not impair the characteristics.

Such α, β-unsaturated carboxylic acid modified product of linear low-density polyethylene II is usually obtained by adding the above-mentioned linear low-density polyethylene II and α, β-unsaturated carboxylic acid modifier to a reaction initiator. It can be produced by melt-kneading below.

The amount of the α, β-unsaturated carboxylic acid modifier used is because the reactivity of the linear low density polyethylene II and the modifier is high,
Normally, use 1.1 to 1.5 times the planned graft amount.

As the reaction initiator, a commonly used organic peroxide type reaction initiator such as t-butyl-hydroperoxide is used. In addition to organic peroxides, cumene double bodies such as 2,3-dimethyl-2,3-diphenylbutane and derivatives thereof can be used. Since such a reaction initiator has a milder reaction initiation mechanism than an organic peroxide-based reaction initiator, it is possible to reduce the occurrence of gelation and the decrease of the melt index due to modification, and thus the reaction initiator of the present invention can be used. It is suitable as a two-component reaction initiator (further, as a reaction initiator when a linear low density polyethylene I modified with α, β-unsaturated carboxylic acid is used as the first component). The reaction initiator is in the range of the usual amount used (usually, the molar ratio to the amount used of the modifier is 0.01 to 0.1).
Double) amount is used. By carrying out the graft polymerization reaction in this manner, 75% by weight or more of the usually used α, β-unsaturated carboxylic acid modifier is graft polymerized.

The modified linear low-density polyethylene composition of the present invention comprises a linear low-density polyethylene I as a first component and / or an α, β-unsaturated carboxylic acid modified product thereof and a linear low-density polyethylene as a second component. The modified α, β-unsaturated carboxylic acid of II is contained in a weight ratio of 60:40 to 99: 1. In particular,
By setting the weight ratio of the first component and the second component within the range of 70:30 to 95: 5, the polymer compound and the composition of the present invention in a laminated film with another polymer compound such as nylon The adhesiveness at the normal temperature tends to improve.

In the composition of the present invention, when the amount of the first component is small, the heat resistance is not sufficiently improved, and when the amount of the second component is small, the adhesiveness is not sufficiently expressed. And, the effect that the composition of the present invention has good adhesiveness at high temperature and the effect that it has good hot water adhesiveness is that the composition of the present invention has the first component and the second component within the above range. It is achieved by containing.

The modified linear low-density polyethylene composition of the present invention usually has a melt index of 1 g / 10 minutes or more (preferably 1 to 20 g / 1.
Since the melting point is within the range of 115 to 130 ° C., it has good extrusion molding performance. Furthermore, the density is usually in the range of 0.915-0.930 g / cm ³ .

Further, when viewed from the composition of the present invention as a whole, 0.3 x 10 ^{-6 to} 0.8 x 10 ^-4 mol of the α, β-unsaturated carboxylic acid-modified component is usually graft-polymerized with respect to 1 g of the polyethylene component in the composition. The composition of the present invention not only has good adhesiveness to steel plates (adhesiveness under static conditions), but is also extruded with the composition of the present invention in a molten state and another polymer compound such as nylon. A laminated film obtained by molding using a device or the like has excellent adhesiveness (adhesiveness under dynamic conditions) between the polymer compound and the composition of the present invention.

In particular, the composition of the present invention has extremely excellent adhesive performance under high temperature conditions as compared with the conventional composition.

Usually, the adhesion performance at high temperature is evaluated by thermocompression bonding the laminated film and measuring the tension required for peeling from the thermocompression bonded portion at a predetermined temperature (for example, 100 ° C.). However, when used for packaging retort foods, for example, simply having a high adhesive strength at a high temperature as described above is not sufficient as a characteristic, and the evaluation by the ordinary adhesive strength at a high temperature as described above is performed. Outside, the same conditions as when performing heat sterilization,
That is, it is necessary that the pressed contact portion does not peel off even after a certain period of time under contact with high-temperature water, that is, the hot water resistance is good.

The composition of the present invention, compared to conventional modified polyethylene composition, further modified linear low density polyethylene composition,
This hot water resistance is particularly excellent. Specifically, when the composition of the present invention is subjected to thermocompression bonding as an adhesive layer,
It has an excellent property that the thermocompression bonded portion does not peel off for at least 30 minutes even when it is contacted with heated water at 103 ° C. in a pressure vessel. Therefore, when the composition of the present invention is used as an adhesive, the thermocompression bonding portion does not peel off due to contact with heated water during heat sterilization, etc., and the contents do not leak out.

Furthermore, for example, two layers of laminated film obtained by extruding nylon (polyamide resin) and the composition of the present invention to have layer thicknesses of 20 μm and 40 μm, respectively, are used so that the composition of the present invention faces each other. The test piece is placed under a normal condition (for example, a temperature of 170 ° C, a pressure of 2 kg / cm ² , and a pressure bonding (heat sealing) for 1 second at a temperature of 100 ° C and a peeling speed of 50 m.
When the T-type peel test is performed under the condition of m, the adhesive strength of the composition of the present invention is higher than the resin strength, so that the resin (a laminated film of nylon and the composition of the present invention is laminated before the peeling of the thermocompression-bonded portion) ) Disconnection occurs. That is, such a resin film usually causes resin breakage when a tension of 1.0 kg / 1.5 cm or more is applied at 100 ° C., but the adhesive strength of the thermocompression bonding portion is usually 1.0 kg / 1.5 cm or more. Therefore, the thermocompression bonding portion does not peel off before resin injection occurs.

Therefore, the composition of the present invention is suitable for use as an adhesive for a laminated film for packaging retort foods, which requires high hot water adhesive strength and high adhesive strength at high temperature.

The modified linear low-density polyethylene composition of the present invention can be produced by dry-blending the above-mentioned first component and second component, and then kneading the mixture in a molten state.

A normal mixer such as a Henschel mixer can be used for dry blending, and a normal melt kneader such as a single-screw extruder can be used for melt kneading.
Further, the melt-kneading, for example, when using a single-screw extruder, usually set the heating temperature within the range of 180 ~ 260 ℃,
The residence time is set to 0.1 to 5 minutes, and the operation is performed in an atmosphere of an inert gas such as nitrogen.

It should be noted that, in the melt-kneading, in addition to the above-mentioned first component and second component, other resin components, or commonly used additives are blended within a range that does not impair the characteristics of the composition of the present invention. You can also

Next, examples and comparative examples of the present invention will be shown.

[Example 1] Melt index (MI) 2.2 g / 10 minutes, density 0.918 g / c
m ^3, melting point 125 ° C., 4-methyl - were prepared the content of the repeating unit derived from pentene-1 3.1 mol% of linear low density polyethylene -I (LLDPE-I). In addition, this LLDPE
The Vicat softening point of -I was 107 ° C.

Separately, melt index 2.0g / 10min, density 0.919g / c
Linear low density polyethylene-II (LLD) with m ³ , melting point 123 ° C. and content of repeating units derived from butene-1 of 3.6 mol%.
PE-II) and 1 g LLDPE-II with 1 × 10 ^-4 mol maleic anhydride and 0.32 × 10 ^-4 mol 2,3-dimethyl-2,3
-Diphenylbutane is mixed with a Henschel mixer, and the resulting mixture is uniaxial extruder (screw diameter: 50 m
m, L / D = 24) and heated to 260 ° C. under a nitrogen atmosphere and melt-kneaded at a residence time of about 1 minute to produce a maleic acid modified product of linear low density polyethylene-II.

The maleic acid modified product of LLDPE-II thus obtained was 1 g of LLDPE-II.
To 0.8 × 10 ^-4 mol of maleic anhydride is graft-polymerized, the melt index is 0.6 g / 10 minutes, the density is
The melting point was 0.917 g / cm ³ and the melting point was 119 ° C.

To 90 parts by weight of LLDPE-I described above, 10 parts by weight of a maleic acid modified product of LLDPE-II was added and mixed, and a modified linear low density polyethylene composition was obtained by melt-kneading using the above single-screw extruder. Was manufactured.

The modified linear low-density polyethylene composition obtained had a melt index of 1.9 g / 10 minutes, a density of 0.918 g / cm ³ , and a melting point of 125 ° C.

[Example 2] A modified linear low-density polyethylene composition was produced in the same manner as in Example 1 except that LLDPE-1 having the physical properties described below was used instead of LLDPE-I.

Melt index: 4.2g / 10min Density: 0.922g / cm ³ Melting point: 126 ℃ Content of repeating unit derived from octene-1: 2.4mol% Vicat softening point: 109 ℃ Obtained modified linear low density polyethylene The composition had a melt index of 3.5 g / 10 minutes, a density of 0.922 g / cm ³ and a melting point of 126 ° C.

[Example 3] The LLDPE-I used in Example 2 was prepared by using 0.1x10 ^-4 mol of maleic anhydride and 0.04x10 ^-4 mol of t-butyl hydroperoxide, except that the heating temperature was 220 ° C. Was treated with maleic acid in the same manner as in Example 1 to obtain LL
A maleic acid modified product was prepared on DPE-I. The obtained LLDPE
-I maleic acid modified product is 0.0 with respect to 1 g of LLDPE-I.
6 × 10 ^-4 mol of maleic anhydride is graft polymerized, melt index is 3.2 g / 10 minutes, density is 0.922 g / cm
³ , and the melting point was 126 ° C and the Vicat softening point was 109 ° C.

Next, 90 parts by weight of a maleic acid modified product of LLDPE-I,
A modified linear low-density polyethylene composition was prepared by mixing 10 parts by weight of the maleic acid modified product of the linear low-density polyethylene-II used in Example 1 by the same method as that used in Example 1 and melt-kneading. Manufactured.

The obtained modified linear low-density polyethylene composition had a melt index of 2.8 g / 10 minutes, a density of 0.921 g / cm ³ , and a melting point of 126 ° C.

Example 4 The amount of LLDPE-I used in Example 1 was 98 parts by weight, and LLDPE-I was used.
A modified linear low density polyethylene composition was produced in the same manner except that the amount of the maleic acid modified product of PE-II used was 2 parts by weight.

The modified linear low-density polyethylene composition thus obtained had a melt index of 2.1 g / 10 minutes, a density of 0.918 g / cm ³ , and a melting point of 125 ° C.

Comparative Example 1 In Example 1, LLDPE-I was used instead of LLDPE-I.
Modified linear low-density polyethylene in the same manner except that (melt index 4.0 g / 10 min, density 0.935 g / cm ³ , melting point 123 ° C., content of repeating units derived from butene-1 1.9 mol%) was used. A composition was produced.

The modified linear low-density polyethylene composition thus obtained had a melt index of 2.1 g / 10 minutes, a density of 0.918 g / cm ³ , and a melting point of 125 ° C.

Comparative Example 2 A modified linear low density polyethylene composition was produced in the same manner as in Example 1, except that the amounts of the LLDPE-I and LLDPE-II modified maleic acid used were both 50 parts by weight.

[Comparative Example 3] In Example 3, a maleic acid-modified product of LLDPE-I and LLD were used.
A modified linear low density polyethylene composition was produced in the same manner except that the amount of PE-II used with the maleic acid modified product was both 50 parts by weight.

Evaluation item (i) Adhesion strength test between nylon and adhesive Using an inflation molding machine (die diameter: 100 mm, lip clearance: 1.25 mm), BUR: 1.3, folding diameter 200 mm, pulling speed 18 m / min, water-cooled inflation Nylon (made by Ube Industries, Ltd., grade name: 5033B) 20 on the outer layer under certain conditions
μm, modified linear low density polyolefin composition (thickness: manufactured in the example (or comparative example)) for the intermediate layer and the inner layer
A laminated film having a two-component three-layer structure consisting of 20 μm each was formed into a tubular shape and cut into a length of 150 mm to produce a tubular shaped body. The temperature of the extruder was around 230 ° C in the outer layer and around 210 ° C in the intermediate layer and the inner layer. It should be noted that, when forming the laminated film, the mutual adhesion of the films did not occur.

The obtained laminate was subjected to a T-type adhesion test between nylon and an adhesive at a peeling speed of 50 mm using an Instron tensile strength tester according to the method specified in JIS-K-6854.

(Ii) Heat-resistant and water-resistant adhesive property of heat-sealed part A tubular molded product (length: 150 mm, width: 20 mm) made of a laminated film of nylon and an adhesive, which is molded as described above, and has open ends (the inner surface is an adhesive) One end of the
Heat sealing was carried out under the conditions of ℃, pressure 2 kg / cm ² and heating time 1 second.

150 ml from the other end (entrance) that is not heat-sealed
After adding water, the inlet portion was heat-sealed under the same conditions as above to prepare a sample for heat resistance test.

The obtained sample was put into a pressure cooker heated to 90 ° C, and the inside of the cooker was maintained at 103 ° C for 30 minutes.

After 30 minutes, the sample was taken out and the state of the heat-sealed portion was observed.

(Iii) Adhesive strength test of heat-sealed portion The adhesive strength of the heat-sealed portion adhered as described above was measured according to the method described in (i).

The evaluation results are shown in Table 1.

Claims (6)

[Claims] 1. A linear low-density polyethylene I containing a repeating unit derived from an α-olefin I having 5 to 10 carbon atoms and / or a modified product of an α, β-unsaturated carboxylic acid thereof, and 3 or 4 carbon atoms. A linear low-density polyethylene II containing a repeating unit derived from α-olefin II of α, β-unsaturated carboxylic acid modified product in a weight ratio within the range of 60:40 to 99: 1. A modified linear low-density polyethylene composition comprising: 2. A linear low density polyethylene I having a melt index in the range of 0.1 to 10 g / 10 min and a density of
The modified linear low density polyethylene composition according to claim 1, which is a linear low density polyethylene within a range of 0.91 to 0.94 g / cm ³ . 3. The linear low-density polyethylene I contains a repeating unit derived from an α-olefin I at a content ratio within the range of 0.1 to 10 mol%. The modified linear low density polyethylene composition described. 4. The linear low density polyethylene II has a melt index of 0.1 to 20 g / 10 minutes and a density of
The modified linear low density polyethylene composition according to claim 1, which is a linear low density polyethylene within a range of 0.90 to 0.95 g / cm ³ . 5. The linear low density polyethylene II contains a repeating unit derived from an α-olefin II in a content within a range of 0.1 to 10 mol%. The modified linear low density polyethylene composition described. 6. An α, β-unsaturated carboxylic acid modified product of linear low density polyethylene II is 1 g of linear low density polyethylene II.
The modification according to claim 1, wherein 0.1 × 10 ^{−4 to} 4.5 × 10 ⁻⁴ mol of the α, β-unsaturated carboxylic acid modifying component is graft-polymerized. Linear low density polyethylene composition.