JPH0632949A - Resin composition and its use - Google Patents

Abstract

PURPOSE:To obtain a resin composition which can give an easy-to-peel heat sealing material excellent in low-temperature heat sealability and capability of high-speed drawdown by mixing an ethylene/alpha,beta-unsaturated carboxylic acid copolymer with a low-density PE and a polybutene-1 in a specified ratio. CONSTITUTION:An ethylene copolymer resin composition is obtained by mixing 100 pts.wt. in total of 30-70 pts.wt. ethylene/alpha,beta-unsaturated carboxylic acid copolymer (A) having an alpha,beta-unsaturated carboxylic acid content of 8-20wt.% and 70-30 pts.wt. low-density polyethylene (B) with 3-20 pts.wt. polybutene-1 or by mixing 100 pts.wt. in total of components A and B with 3-20 pts.wt. in total of polybutene-1 and polypropylene. This composition can give an easy-to- peel heat-sealing material excellent in low-temperature heat sealability, hot tack, sealability and capability of high-speed drawdown.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a resin composition which is excellent in heat-sealing strength, hot tacking property, and sealing property, and which can be an easy-peelable heat-sealing material excellent in high-speed thinning property, and Regarding its use. Particularly, the present invention relates to a resin composition in which the stringing phenomenon at the time of opening is reduced when used as an easily-openable heat-sealing material.

[0002]

BACKGROUND OF THE INVENTION Conventionally, packaging bags for snacks such as potato chips have been used for aluminum vapor-deposited polyethylene terephthalate (VM-) in consideration of aesthetics, waist strength, light-shielding property, and prevention of oxygen and water vapor permeation. PET) or a laminated film using a biaxially oriented polypropylene film is used. Polypropylene is used as the heat-sealing layer of this laminated film, and the heat-sealing layer made of this polypropylene is formed on the inner surface of the VM-PET layer via a polyethylene layer. By thus interposing the polyethylene layer, it becomes easy to form the polypropylene layer on the VM-PET layer by extrusion coating, but there are drawbacks that the process becomes complicated and the cost becomes high. Moreover, in manufacturing the packaging bag, it is necessary to heat seal the polypropylenes which are the heat seal layers, but it must be processed at a relatively high temperature, and since the heat seal strength in the heat seal part is too high, There was a problem that it was difficult to open it easily.

[0003] By the way, conventionally, there have been some proposals for an easily openable seal material, and many seal materials which are easily opened when sealed with different seal materials are well known. However, when the same sealing materials are adhered to each other to form a seal, the sealing strength is so strong that the opening property is not easy in many cases. Moreover, it is difficult for many heat seal materials to form a heat seal layer on a base material layer at a high speed by an extrusion coating method.

For example, Japanese Patent Publication No. 64-4535 discloses a resin composition comprising a linear low density polyethylene, a high pressure polyethylene and an ionomer, which is excellent in extrusion processability and heat sealability, and has various base materials. It is shown that it can be laminated to. However, such a resin composition is extrusion coated onto a thermoplastic resin such as polyester to form a heat-sealing layer, and when the heat-sealing layers are adhered to each other, the sealing strength is too strong, so that the packaging material can be easily opened. It was difficult to use.

Further, Japanese Unexamined Patent Publication (Kokai) No. 63-114646 discloses that a composition comprising an ionomer, polybutene-1 and polyethylene is used as a seal layer when a polyolefin resin is used as a mating seal layer. In this proposal, the composition of the ionomer is not examined at all, but when the compositions are sealed with each other,
Unless a specific ionomer is selected, a so-called stringing phenomenon occurs in which a fibrous seal layer remains on the peeled surface during opening. The proposal does not teach anything about such a phenomenon and its solution. Further, the above composition has a problem that it is difficult to form a seal layer by a lamination process.

JP-A-63-295641 proposes a resin composition composed of an ethylene / carboxylic acid copolymer, polybutene-1 and polypropylene, and an easy-open packaging material composed of this resin composition. However, as can be seen from the examples, the fact that the seal strength has a large temperature dependency and the adjustment of the seal strength is not easy is a serious problem in practical use. There is also a drawback that a considerable number of stringing phenomena are recognized when the package is opened.

Japanese Patent Application Laid-Open No. 2-9294 proposed by the applicant
No. 3 discloses an easy-open seal material composed of an ethylene / unsaturated carboxylic acid copolymer or a metal salt thereof, polypropylene and polyethylene. In this proposal, the temperature dependence of the seal strength is considerably reduced, but it cannot be said to be sufficient. Another problem is that a slight stringing phenomenon is recognized when the package is opened.

Further, the applicant of the present invention has proposed an easily openable material composed of high-pressure polyethylene and an ethylene / (meth) acrylic acid copolymer or a metal salt thereof in JP-A-3-92340, but the stringing phenomenon Has not been resolved.

In view of such drawbacks of the prior art, the inventor of the present invention is capable of extrusion coating, has excellent low-temperature heat-sealing property, hot-tack property and easy-opening property, and when heat-sealing the same materials. In addition, a heat seal material that further reduces stringing on the unsealed surface was examined. As a result, two kinds of ethylene ・ α, β- with different acid contents
It was found that a composition composed of an unsaturated carboxylic acid copolymer, or a composition obtained by adding a small amount of a crystalline polyolefin to the composition, meets the purpose, and Japanese Patent Application No. 3-20
Proposed as No. 0913. In this proposal, it is considered essential to use ethylene / α, β-unsaturated carboxylic acid copolymers with low acid content, and polyethylene / α, β-unsaturated carboxylic acid copolymers with low acid content should be used instead of polyethylene. No improvement was found in the stringing phenomenon even with the use of.
However, in the subsequent study, it was found that when a small amount of polybutene-1 is used in combination, a resin composition free from the stringing phenomenon can be obtained without using an ethylene / α, β-unsaturated carboxylic acid copolymer having a low acid content. The present invention has been reached.

[0010]

The present invention is capable of extrusion coating, is excellent in low-temperature heat-sealing property, hot-tack property, and easy-opening property, and is excellent in high-speed thin-pulling property. A resin composition capable of becoming a heat seal material capable of reducing stringiness, a heat seal material comprising the resin composition, an easy-open seal material, and a laminate in which the resin composition is laminated, and The object is to provide a packaging material composed of this laminate.

[0011]

SUMMARY OF THE INVENTION The ethylene copolymer resin composition according to the present invention has an α, β-unsaturated carboxylic acid content of 8 to 20% by weight.
30 to 70 parts by weight of ethylene / α, β-unsaturated carboxylic acid copolymer (A) and low density polyethylene (B)
Polybutene-1 (C) is added in an amount of 3 to 20 to 70 to 30 parts by weight and a total of 100 parts by weight of the ethylene / α, β-unsaturated carboxylic acid copolymer (A) and low density polyethylene (B).
It is characterized by being mixed by weight, or polybutene-1 (C) and polypropylene (D) in a proportion of 3 to 20 parts by weight.

The heat seal material and the easy-open seal material according to the present invention are characterized by comprising the above ethylene copolymer resin composition. The laminate according to the present invention,
It is characterized in that the above ethylene-based copolymer resin composition is laminated on the base material layer.

The packaging material according to the present invention is characterized by comprising the above laminated body. ADVANTAGE OF THE INVENTION According to this invention, the resin composition which can be used as a heat-sealing material which is excellent in low-temperature heat-sealing property, hot-tack property, sealing property, and excellent in high-speed thinning property (easy peel) (easy peel) It is possible to provide a laminate and a packaging material using the resin composition.

[0014]

DETAILED DESCRIPTION OF THE INVENTION The ethylene-based copolymer resin composition, heat seal material, easy-open seal material, laminate and packaging material according to the present invention will be specifically described below.

The ethylene copolymer resin composition according to the present invention comprises an ethylene / α, β-unsaturated carboxylic acid copolymer (A) having an α, β-unsaturated carboxylic acid content of 8 to 20% by weight.
And low density polyethylene (B) and polybutene-1 (C)
Or a composition containing polypropylene (D) in addition to the above composition.

The ethylene / α, β-unsaturated carboxylic acid copolymer (A) (hereinafter sometimes referred to as “(A) component”) used in the present invention is an α, β-unsaturated carboxylic acid. The unit is contained in the range of 8 to 20% by weight, preferably 12 to 18% by weight. Such an ethylene / α, β-unsaturated carboxylic acid copolymer (A) is obtained by directly copolymerizing ethylene and an α, β-unsaturated carboxylic acid, and is generally a high pressure polymerization method. Can be manufactured by.

Here, as the α, β-unsaturated carboxylic acid,
Acrylic acid, methacrylic acid, maleic anhydride, monomethyl maleate and the like can be exemplified, but acrylic acid or methacrylic acid is particularly preferable.

If the content of α, β-unsaturated carboxylic acid is less than the above range, the stringing phenomenon tends to occur.
Further, if a material having a content larger than the above range is used, the compatibility is lowered and the extrusion coating process becomes difficult. Such an ethylene / α, β-unsaturated carboxylic acid copolymer (A) has a 19
Mettle flow rate is 2 at 0 ℃ and 2160g load
It is preferably in the range of ˜100 g / 10 minutes, and particularly preferably in the range of 5 to 80 g / 10 minutes.

The low-density polyethylene (B) (hereinafter sometimes referred to as "component (B)") used in the present invention is a high-pressure polyethylene or a linear polyethylene and has a density of 0.90 to. It is in the range of 0.93 g / cm ³ . The high-pressure polyethylene may contain a very small amount of polar monomer, but a homopolymer is usually used. Further, linear polyethylene is usually a polymer obtained by copolymerizing ethylene and an α-olefin having 3 or more carbon atoms by a medium-low pressure method. Such low density polyethylene (B) has a melt flow rate of 1 to 10
It is preferably in the range of 0 g / 10 minutes, especially 2 to 3
It is preferably in the range of 0 g / 10 minutes.

In the present invention, polybutene-1 (C) is used in addition to the ethylene / α, β-unsaturated carboxylic acid copolymer (A) and low density polyethylene (B), or polybutene-1. (C) and polypropylene (D) are used.

Polybutene-1 (C) used in the present invention
Is a homopolymer of butene-1 or a copolymer of butene-1 mainly containing butene-1 and other olefins, and particularly having a melt flow rate at 190 ° C. and a load of 2160 g of 0.1 to 100 g / 10. Min, especially 0.2-40g / 1
It is preferably in the range of 0 minutes.

The polypropylene (D) used in the present invention is a homopolymer of propylene or a copolymer of propylene mainly containing propylene and other olefins, and has a melt flow rate at 230 ° C. and a load of 2160 g. 0.5 to 100 g / 10 minutes, especially 2 to 30 g /
It is preferably in the range of 10 minutes.

The mixing ratio of the component (A) and the component (B) is
30/70 to 70 by weight ratio (component (A) / component (B))
/ 30, preferably 40/60 to 60/40. If the compounding ratio is out of this range,
The heat seal strength may become too strong, the stringiness may be deteriorated, and the extrusion processability may be deteriorated.

Polybutene is used as the component (A) and the component (B).
As for the amount of polybutene-1 (C) to be blended with -1 (C), the preferred blending range varies depending on the blending ratio of the component (A) and the component (B), but It is desirable that the amount is in the range of 3 to 20 parts by weight, preferably 5 to 15 parts by weight, based on 100 parts by weight in total of the component (B).

When the polybutene-1 (C) and the polypropylene (D) are blended with the component (A) and the component (B), the total blending amount is the blending ratio of the component (A) and the component (B). Although the preferred blending range varies depending on the composition, it is desirable that the content is 3 to 20 parts by weight, preferably 5 to 15 parts by weight, based on 100 parts by weight of the total of the components (A) and (B). In this case, the polybutene-1 (C) is used in an amount of 2 parts by weight or more, preferably 4 to 8 parts by weight, based on 100 parts by weight of the total of the components (A) and (B). , Polypropylene (D) has (A) component and (B)
It is desirable to use 10 parts by weight or less, preferably 4 to 8 parts by weight, based on 100 parts by weight in total with the components.

Polybutene-1 (C) serves to reduce the stringing phenomenon and to reduce the temperature dependence of the seal strength and expand the temperature range in which sealing is possible. Since it tends to increase the stringing phenomenon, it is necessary to use an appropriate amount. Further, polypropylene (D) is effective in adjusting the seal strength, and the seal strength can be decreased as the compounding amount is increased, but if the compounding amount is excessively increased, the seal strength becomes too small and the sealing property is improved. Is deteriorated or the temperature dependence of the seal strength is increased, which causes a defect.

The melt viscosity of the ethylene-based copolymer resin composition according to the present invention can vary widely, but in the application of the ethylene-based copolymer resin composition by extrusion coating on a base material layer, 190 ° C., Melt flow rate at 2160 g load is 0.5 to 30 g / 10 minutes, especially 1 to 20
It is preferably in the range of g / 10 minutes.

The ethylene copolymer resin composition according to the present invention as described above is excellent in low-temperature heat-sealing property, hot-tack property, and sealing property, and is excellent in high-speed thinning property. In particular, it can be suitably used as an easily openable heat seal material. In order to use the ethylene-based copolymer resin composition of the present invention as a heat-sealing material, the above-mentioned ethylene-based copolymer resin composition is formed as a heat-sealing layer on a base material layer and used as a laminate. It is preferable. The base material layer used at this time may be a single layer or a multi-layer, but the portion contacting the heat seal layer is usually preferably made of a thermoplastic resin or a metal. In such a substrate layer, polyvinylidene chloride coating treatment, anchor coating treatment, corona treatment, or the like may be applied to the portion that comes into contact with the heat seal layer. Further, a metal such as aluminum or a metal oxide may be vapor-deposited on the base material layer.

Specific examples of such a substrate include polyethylene terephthalate (PET) and polyamide (P
A), polyvinyl alcohol (PVOH), ethylene
Vinyl alcohol copolymer (EVOH), polyvinylidene chloride (PVDC), polypropylene (PP), oriented polypropylene (OPP), aluminum deposited polyethylene terephthalate (VM-PET), aluminum deposited polypropylene (VM-PP), aluminum foil, cellophane. Are used. These base material layers may be multilayered as described above, and may have a structure such as PP / PE / VM-PET.

In particular, when the oriented polypropylene (OPP), which is widely used as a packaging material, is used as the base material layer in a single layer or multiple layers, the ethylene copolymer resin composition according to the present invention is formed on the base material layer. Since the packaging material obtained by forming the heat-sealing layer made of can be heat-sealed at a low temperature, the trouble that polypropylene (PP) shrinks during heat-sealing can be avoided. In addition, it is preferable to use a material having excellent gas barrier properties such as polyethylene terephthalate (PET) or a material provided with a vapor deposition layer as the base material layer because deterioration of the contents due to oxidation and moisture absorption can be prevented.

In the present invention, the thickness of the base material layer and the heat seal layer is arbitrary, but the base material layer is usually 10 to 100 μm thick.
It is preferable that the heat seal layer has a thickness of about 10 to 50 μm.

Although various methods can be adopted for producing the laminate having the above-mentioned constitution, the method of extrusion coating the above-mentioned ethylene copolymer resin composition on the base material layer is the most preferable. At this time, an anchor coating agent may be applied to the base material layer in order to enhance the adhesive force with the ethylene-based copolymer resin composition layer.

Such a laminate can be used as a packaging material by heat-sealing the heat-sealing layers. A typical application of the packaging material is a snack confectionery packaging bag, for example, drawn polypropylene / polyethylene / V
By forming the M-PET / heat-sealing layer (ethylene-based copolymer resin composition) in a four-layer structure, it is possible to produce a packaging bag having excellent gas barrier properties, light-shielding properties, aesthetics, and easy opening properties. it can.

When the ethylene copolymer resin composition according to the present invention is used as a packaging material, the heat-sealing temperature is slightly different depending on the composition of the ethylene copolymer resin composition used as the heat-sealing material. 120-15
It can be carried out at a low temperature of about 0 ° C. and, if desired, at a higher temperature. Heat seal strength is 0.5-
2.0 kg / 15 mm, preferably 0.8-1.2 kg /
It is preferably 15 mm.

When the ethylene copolymer resin composition according to the present invention is used as an easily openable packaging material, the hot tack property measured by the method described below is from 1 to 40.
mm, preferably 1 to 30 mm.

[0036]

When the ethylene-based copolymer resin composition of the present invention is used as a heat-sealing layer of a multilayer packaging material,
Packaging materials can be produced by extrusion coating at high processing speeds. Such a packaging material is 120-1
Even when heat sealing is performed at a low temperature of about 50 ° C., high-speed bag making is possible because of excellent hot tack property and heat sealing strength, and bag breakage trouble does not occur. Further, since the seal strength is appropriate, the opening property is excellent, and since there is no stringing at the time of opening, the commercial value is not reduced.

[0037]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

First, extrusion lamination conditions and high-speed thin drawability when extrusion-laminating the ethylene-based copolymer resin composition according to the present invention on a substrate, low-temperature heat sealability of a laminate having a heat seal layer, and stringing The method of evaluating the heat resistance and low temperature hot tack will be described.

[Extrusion lamination conditions] Molding machine: Laminator with a diameter of 65 mm (L / D =
32) Dice: Inner deckle die Effective width of die: 800 mm Die opening: 0.8 x 500 mm Air gap: 110 mm Molding temperature: 305 ° C (directly below the die) Resin extrusion rate: 930 g / 10 minutes (take-off speed) 80m / min × equivalent amount of laminated resin thickness 25μm) Collection speed: 80m / min Base material: Kraft paper (50g / m ² ) (1) High speed thin drawability Resin extrusion rate under the above extrusion lamination conditions (930g / min) ) Is kept constant, the take-up speed is gradually increased from 80 m / min to measure the take-up speed when the resin film starts to break, and this is taken as a drawdown.

(2) Low temperature heat sealing property In the present invention, the low temperature heat sealing property was evaluated as follows. That is, a laminated film having a four-layer structure as a base material layer [biaxially oriented polypropylene film; 20 μm / (anchor coating agent) / low density polyethylene (LDP
E); 20 μm / aluminum vapor-deposited polyester film; 1
2 μm], the resin composition was extrusion coated on the aluminum vapor-deposited polyester film surface of the base material layer under the extrusion lamination conditions described above so as to have a thickness of 25 μm, thereby forming a heat-sealing layer to produce a laminate.

With respect to the laminate obtained as described above, the coated heat-sealing layers were heated at a temperature of 120.
Heat sealed at ~ 160 ° C. Heat sealing uses a single-sided heating plate type heat sealer, and the heat sealing conditions are
Seal width: 10 mm, seal pressure: 2 kg / cm ² , seal time: 0.5 sec., Seal bar: 30 cm × 10 m
m, the width from the laminate heat-sealed under these conditions;
Ten test pieces having a length of 15 mm and a length of 15 mm were prepared.

With respect to this test piece, the maximum value of the heat seal strength when peeling at 90 ° at a pulling rate of 300 mm / min in an atmosphere of 23 ° C. and 50% relative humidity was measured, and an average value of 10 test pieces was obtained. Is the low temperature heat sealability.

(3) Stringing property The stringing property was evaluated as follows based on the length and number of the fibrous seal layer remaining on the peeled surface of the test piece after the low temperature heat seal property measurement of (2) above. .

◯: Almost no fibrous material was observed on the peeled surface Δ: Some fibrous material was recognized on the peeled surface × ... Fibrous material was observed on the entire peeled surface

(4) Low Temperature Hot Tack Property The low temperature hot tack property was evaluated as follows by using a laminate obtained under the above extrusion lamination conditions as a test piece having a width of 4 cm and a length of 63 cm. .

The method for evaluating the low temperature hot tack property will be described below with reference to FIG. FIG. 1 is a schematic view of a measuring instrument used for evaluating low temperature hot tack property. 1 and 2 in FIG. 1 are heat seal plates of the heat sealer used in the evaluation of (2) low temperature heat sealability described above, in which only the upper side 1 is heated to a predetermined temperature and the lower side 2 is at room temperature. Is. 3a and 3b are the above-mentioned test pieces, and the heat seal layers face each other. This test piece 3a, 3b
Is fixed at the position of the left end 6 and the right end is 45 g each.
Weights 4a and 4b are attached, and the test pieces 3a and 3b are 5
There is an angle of 22.5 ° at the position. The heat seal plates 1 and 2 have a length of 30 cm and a width of 10 mm.

While maintaining the state as shown in FIG. 1, the test pieces 3a and 3b were subjected to the same conditions as the above (2) Low temperature heat sealability.
Is heat-sealed, the fixing of 6 is released at that moment, and the heat-sealed surface is forcibly peeled off by the peeling force (90 g) of the weights 4a and 4b. The peel distance of the heat-sealed surface at that time was measured, and the value was taken as the low temperature hot tack property.

[0048]

Example 1 Ethylene / methacrylic acid copolymer having a methacrylic acid content of 15% by weight (melt flow rate: 6
0 g / 10 min); 46 parts by weight, high-pressure low-density polyethylene (melt flow rate; 10 g / 10 min, density;
0.917 g / cm ³ ); 46 parts by weight of polybutene-1
(Melt flow rate: 1 g / 10 minutes, density: 0.91
0 g / cm ³ ); 8 parts by weight of the composition obtained by melt blending, and the high-speed thinning property, low-temperature heat-sealing property, stringing property, and low-temperature hot-tack property were evaluated by the methods described above. The results are shown in Table 1.

[0049]

Example 2 Ethylene / methacrylic acid copolymer having a methacrylic acid content of 15% by weight (melt flow rate: 6
0 g / 10 min); 46 parts by weight, high-pressure low-density polyethylene (melt flow rate; 10 g / 10 min, density;
0.917 g / cm ³ ); 46 parts by weight of polybutene-1
(Melt flow rate: 1 g / 10 minutes, density: 0.91
0 g / cm ³ ); 4 parts by weight and polypropylene (melt flow rate; 6 g / 10 minutes, density; 0.910 g / c)
m ³ ); 4 parts by weight, and the composition obtained by melt blending was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0050]

Comparative Example 1 Ethylene / methacrylic acid copolymer having a methacrylic acid content of 15% by weight (melt flow rate: 6
0 g / 10 minutes); 50 parts by weight and the composition obtained by melt blending 50 parts by weight of the high-pressure low-density polyethylene used in Example 1 were used, and the physical properties were evaluated in the same manner as in Example 1. . The results are shown in Table 1.

[0051]

Comparative Example 2 Ethylene / methacrylic acid copolymer having a methacrylic acid content of 15% by weight (melt flow rate: 60
g / 10 minutes); 25 parts by weight, high-pressure low density polyethylene used in Example 1; 67 parts by weight, polybutene-1 used in Example 1; 4 parts by weight and polypropylene used in Example 2; Using a composition obtained by melt-blending 4 parts by weight, physical properties were evaluated in the same manner as in Example 1. The results are shown in Table 1.
Shown in.

[0052]

Comparative Example 3 Ethylene / methacrylic acid copolymer having a methacrylic acid content of 10% by weight (melt flow rate: 3
5 g / 10 min): 90 parts by weight, polybutene-1 used in Example 1; 5 parts by weight, and polypropylene used in Example 2; 5 parts by weight, a composition obtained by melt blending, Physical properties were evaluated in the same manner as in Example 1. The results are shown in Table 1.
Shown in.

[0053]

Comparative Example 4 Ethylene / methacrylic acid copolymer having a methacrylic acid content of 12% by weight (melt flow rate 14 g
/ 10 minutes); 55 parts by weight, high-pressure low density polyethylene used in Example 1; 35 parts by weight, and polypropylene used in Example 2; 10 parts by weight. The physical properties were evaluated in the same manner as in Example 1.
The results are shown in Table 1.

[0054]

Comparative Example 5 Zinc salt of ethylene / methacrylic acid copolymer (melt flow rate: 12 g / 10 minutes, methacrylic acid content: 15% by weight, methacrylic acid ionization rate by zinc: 23%); 46 parts by weight Composition obtained by melt blending 46 parts by weight of high-pressure low density polyethylene used in Example 1, 4 parts by weight of polybutene-1 used in Example 1 and 4 parts by weight of polypropylene used in Example 2 Using the product, the physical properties were evaluated in the same manner as in Example 1. The results are shown in Table 1.
Shown in.

[0055]

Comparative Example 6 The structure of the evaluation sample is as shown below.
Physical properties were evaluated in the same manner as in Example 1 using the laminate.

Sample composition: Stretched polypropylene (OP
P) 20 μm / anchor coating agent / low density polyethylene (LDPE) 20 μm / aluminum-deposited polyester 12 μm / anchor coating agent / low density polyethylene (LDPE) 20 μm / unstretched polypropylene (C
Table 1 shows the results of PP) 25 μm (heat seal layer).

[0057]

[Table 1]

[Brief description of drawings]

FIG. 1 is a schematic view of a measuring device used for evaluation of low temperature hot tack property.

[Explanation of symbols] 1, 2 Heat seal plates 3a, 3b Test pieces 4a, 4b Weight

Claims (7)

[Claims] 1. An α, β-unsaturated carboxylic acid content of 8 to 20.
30 to 70 parts by weight of ethylene / α, β-unsaturated carboxylic acid copolymer (A), 70 to 30 parts by weight of low-density polyethylene (B), and the above-mentioned ethylene / α, β-unsaturated carboxylic acid Acid copolymer (A)
Polybutene-1 (C) is blended in a proportion of 3 to 20 parts by weight with respect to a total of 100 parts by weight of the low density polyethylene (B) and the low density polyethylene (B). 2. An α, β-unsaturated carboxylic acid content of 8 to 20.
30 to 70 parts by weight of ethylene / α, β-unsaturated carboxylic acid copolymer (A), 70 to 30 parts by weight of low-density polyethylene (B), and the above-mentioned ethylene / α, β-unsaturated carboxylic acid Acid copolymer (A)
Polybutene-1 (C) and polypropylene (D) are blended in a proportion of 3 to 20 parts by weight with respect to a total of 100 parts by weight of low-density polyethylene (B) and ethylene-based copolymer. Polymer resin composition. 3. A heat seal material comprising the ethylene copolymer resin composition according to claim 1 or 2. 4. An easily-openable heat-sealing material comprising the ethylene-based copolymer resin composition according to claim 1 or 2. 5. An ethylene / α, β-unsaturated carboxylic acid copolymer (A) having a content of α, β-unsaturated carboxylic acid of 8 to 20% by weight in the base material layer 30 to
70 parts by weight, low density polyethylene (B) 70 to 30 parts by weight, and the above ethylene / α, β-unsaturated carboxylic acid copolymer (A)
And 100 parts by weight of low-density polyethylene (B) in total, and 3 to 20 parts by weight of polybutene-1 (C) are blended in an ethylene-based copolymer resin composition to be laminated. Characteristic laminate. 6. An ethylene / α, β-unsaturated carboxylic acid copolymer (A) having an α, β-unsaturated carboxylic acid content of 8 to 20% by weight in the base material layer.
70 parts by weight, low density polyethylene (B) 70 to 30 parts by weight, and the above ethylene / α, β-unsaturated carboxylic acid copolymer (A)
Ethylene copolymer resin composition in which polybutene-1 (C) and polypropylene (D) are added in a proportion of 3 to 20 parts by weight in total with respect to 100 parts by weight of low density polyethylene (B) in total. A laminated body characterized by being laminated. 7. A packaging material comprising the laminate according to claim 5 or 6.