JP3351842B2 - Resin composition and use thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a resin composition which is excellent in heat seal strength, hot tack property, sealability, and excellent in high-speed thinning property and can be used as an easy-opening (easy peel) heat seal material. Regarding its use. In particular, the present invention relates to a resin composition which reduces the stringing phenomenon at the time of opening when used as an easy-opening heat seal material.

[0002]

BACKGROUND OF THE INVENTION Conventionally, packaging bags for snacks, such as potato chips, are made of aluminum-deposited polyethylene terephthalate (VM-VM) in consideration of aesthetic appearance, stiffness, light-shielding properties, and prevention of oxygen and water vapor transmission. A laminated film using PET) or a biaxially oriented polypropylene film is used. Polypropylene is used as the heat seal layer of the laminated film, and the heat seal layer made of the polypropylene is formed on the inner surface of the VM-PET layer via the polyethylene layer. By interposing the polyethylene layer in this way, it is easy to form the polypropylene layer on the VM-PET layer by extrusion coating, but there are drawbacks in that the process is complicated and the cost is high. Moreover, in the production of the packaging bag, it is necessary to heat seal the polypropylene as the heat sealing layer, but it must be processed at a relatively high temperature, and the heat sealing strength in the heat sealing portion is too high, so There was a problem that it was difficult to open easily.

[0003] Heretofore, some proposals have been made on easily-openable seal materials, and many seal materials which can be easily opened when sealing with different seal materials are known. However, when the same seal material is adhered to each other to form a seal, the seal strength is often too strong to easily open. Also, with many heat seal materials, it has been difficult to form a heat seal layer on a base material layer at high speed by an extrusion coating method.

[0004] For example, Japanese Patent Publication No. 4535/1988 discloses that a resin composition comprising a linear low-density polyethylene, a high-pressure process polyethylene, and an ionomer is excellent in extrusion processability and heat sealability. It is shown that the material can be laminated. However, such a resin composition is extrusion-coated on a thermoplastic resin such as polyester to form a heat seal layer, and when the heat seal layers are adhered to each other, the sealing strength is too strong. It was difficult to use.

Japanese Patent Application Laid-Open No. 63-114646 discloses that a composition comprising an ionomer, polybutene-1 and polyethylene is used as a sealing layer when a polyolefin resin is used as a mating sealing layer.
In this proposal, the composition of the ionomer is not studied at all, but when sealing the compositions, unless a specific ionomer is selected, a fibrous sealing layer remains on the release surface when opened. However, there is a problem that a so-called stringing phenomenon occurs. However, Japanese Patent Application Laid-Open No. 63-114646 does not recognize such a problem and does not teach anything about the solution. Further, the above composition has a problem that it is difficult to form a seal layer by lamination.

JP-A-63-2955641 proposes a resin composition comprising an ethylene-carboxylic acid copolymer, polybutene-1 and polypropylene, and an easy-open packaging material comprising this resin composition. However, as can be seen in the embodiment, the temperature dependence of the sealing strength is so large that it is not easy to adjust the sealing strength, which is a serious problem in practical use. There is also a drawback that stringing is noticeable at the time of opening.

Japanese Unexamined Patent Publication No. 2-9294 proposed by the present applicant
No. 3 discloses an easily-openable sealing material comprising an ethylene / unsaturated carboxylic acid copolymer or a metal salt thereof, polypropylene and polyethylene. In the easy-opening seal material proposed in this publication, the temperature dependency of the seal strength is considerably reduced, but it is still not enough, and improvement of the stringing phenomenon at the time of opening is desired.

[0008] The applicant of the present invention has disclosed Japanese Patent Application Laid-Open No. 3-92340.
In the publication, an easy-opening material comprising a high-pressure polyethylene and an ethylene / (meth) acrylic acid copolymer or a metal salt thereof has been proposed. In this easy-opening material, it is further desired to eliminate the stringing phenomenon. ing.

In view of such disadvantages of the prior art, the present inventor has found that extrusion coating is possible, excellent in low-temperature heat-sealing properties, hot-tack properties, and easy-openability, and when the same material is heat-sealed. Next, a heat sealing material that further reduces stringing on the opening surface was examined. As a result, two types of ethylene, α, β
-It has been found that a resin composition comprising an unsaturated carboxylic acid copolymer or a resin composition comprising a small amount of a crystalline polyolefin added thereto has excellent properties as a heat seal material. -200913. In addition, following examination, ethylene • α,
It has been found that a resin composition comprising a β-unsaturated carboxylic acid copolymer, low-density polyethylene, and polybutene-1 has no stringing phenomenon when used as a heat sealing material. No. proposed.

The present inventors have been keen to obtain a more excellent heat sealing material, and have found that ethylene / ethylene oxide having a high acid content is used.
If, in addition to the α, β-unsaturated carboxylic acid copolymer, polyethylene and an ethylene / α, β-unsaturated carboxylic acid copolymer having a low acid content are blended and polybutene is blended,
The present inventors have found that a resin composition free of a stringing phenomenon is obtained, and that high-speed thinning property is improved as compared with the case where only polyethylene is used, and the present invention has been reached.

[0011]

The object of the present invention is that extrusion coating is possible, excellent in low-temperature heat sealing property, hot tack property, easy-opening property, high-speed thinning property, and the opening surface when the same material is heat-sealed. A resin composition that can be a heat sealing material that can reduce stringing in the resin and a sealing material made of the resin composition, an easily-openable sealing material, and a laminate in which the resin composition is laminated,
And a packaging material comprising the laminate.

[0012]

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), low-density polyethylene (B ₁ ), and 9% by weight of α, β-unsaturated carboxylic acid content
Less than or equal to 6% by weight or less of the acid content of the ethylene / α, β-unsaturated carboxylic acid copolymer.
70 to 30 parts by weight of a polymer component (B) comprising an α, β-unsaturated carboxylic acid copolymer (B ₂ ) and the ethylene / α, β-unsaturated carboxylic acid copolymer (A) Polybutene-1 was added to 100 parts by weight of the polymer component (B) in total.
(C) is characterized by being blended in an amount of 3 to 20 parts by weight.

The ethylene copolymer resin composition according to the present invention comprises polybutene-1 (C) instead of polybutene-1 (C).
It may contain (C) and polypropylene (D).
The heat seal material and the easy-open seal material according to the present invention are characterized by comprising the above-mentioned ethylene-based copolymer resin composition.

The laminate according to the present invention is characterized in that the above-mentioned ethylene copolymer resin composition is laminated on a base material layer. A packaging material according to the present invention is characterized by comprising the above-mentioned laminate.

According to the present invention, there is provided a resin composition which is excellent in low-temperature heat-sealing property, hot-tack property, sealing property and easy-opening property (easy-peeling) excellent in high-speed thinning property. A laminate and a packaging material using such a resin composition can be provided.

[0016]

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

The ethylene / α, β-unsaturated carboxylic acid copolymer (A) (hereinafter sometimes referred to as “component (A)”) used in the present invention comprises 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) comprises ethylene and α, β-
It is obtained by directly copolymerizing with an unsaturated carboxylic acid, and can generally be produced by a high-pressure polymerization method.

Here, examples of the α, β-unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic anhydride, monomethyl maleate, etc., and acrylic acid or methacrylic acid is particularly preferred.

If the content of the α, β-unsaturated carboxylic acid is less than the above range, stringing tends to occur. If the content is more than the above range, the compatibility decreases, and the extrusion coating process becomes difficult. It can be difficult.
Such an ethylene / α, β-unsaturated carboxylic acid copolymer (A) can be used at 190 ° C., 21
Melt flow rate at 60 g load is 2 to 100 g
/ 10 minutes, preferably 5 to 80 g
/ 10 minutes is preferable.

The polymer component (B) (hereinafter sometimes referred to as “B” component) used in the present invention is a low-density polyethylene (B ₁ ) (hereinafter referred to as “(B ₁ ) component”). And an ethylene / α, β-unsaturated carboxylic acid copolymer (B ₂ ) having an α, β-unsaturated carboxylic acid content of 9% by weight or less (hereinafter referred to as “(B ₂ ) component”). In some cases.)

The component (B ₁ ) is high-pressure polyethylene or linear polyethylene and has a density of 0.90.
It is preferably 0.93 g / cm ³ . High-pressure polyethylene may contain a very small amount of a polar monomer, but a homopolymer is usually used. 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
_{In 1} ), the melt flow rate is preferably in the range of 1 to 100 g / 10 minutes, particularly preferably in the range of 2 to 30 g / 10 minutes.

The component (B ₂ ) has an α, β-unsaturated carboxylic acid content of 9% by weight or less, preferably 2 to 7% by weight, and at least 6% by weight or more than the acid content of the component (A). , Preferably 7% by weight or more.
If the difference between the acid content of the component (A) and the acid content of the component (B ₂ ) is 6% by weight or less in the resin composition of the present invention, it depends on the amount of the component (B ₂ ) used. If the strength of the seal tends to be too strong, and if the difference in the acid content is too large, the extrudability at the time of forming the heat seal layer tends to decrease, and stringing at the time of opening tends to occur. Therefore, usually, the difference between the acid content of the component (A) and the acid content of the component (B ₂ ) is preferably 16% by weight or less, particularly preferably 14% by weight or less. (B ₂ )
The method for producing the components, the type of the α, β-unsaturated carboxylic acid, the melt flow rate, and the like are the same as those described for the component (A).

The weight ratio of the component (B ₁ ) to the component (B ₂ ) in the present invention can be varied widely, but the ratio of the component (B ₁ ) / the component (B ₂ ) is usually from 20/80 to 80/20.
Preferably 30/70 to 70/30, more preferably 4
It is desirable to be in the range of 0/60 to 60/40. In general, when the amount of the component (B ₁ ) is too large, the extrudability at the time of forming the heat seal layer tends to decrease, and when the amount of the component (B ₂ ) is too large, the heat seal strength is reduced. It tends to be too strong.

The resin composition according to the present invention comprises the above-mentioned ethylene / α, β-unsaturated carboxylic acid copolymer (A), low-density polyethylene (B ₁ ) and ethylene / α, β-unsaturated carboxylic acid copolymer. Polymer component (B) comprising polymer (B ₂ )
And polybutene-1 (C), or polybutene-1 (C) and polypropylene (D).

Polybutene-1 (C) used in the present invention
Is a homopolymer of butene-1 or a copolymer of butene-1 with small amounts of other olefins,
The melt flow rate under a load of 2160 g at 90 ° C. is 0.1 to 100 g / 10 min, especially 0.2 to 40 g / 10
Minutes.

The polypropylene (D) used in the present invention is a homopolymer of propylene or a copolymer of propylene with a small amount of another olefin,
The melt flow rate under a load of 2160 g at 230 ° C. is preferably in the range of 0.5 to 100 g / 10 min, particularly 2 to 30 g / 10 min.

The mixing ratio of the component (A) and the polymer component (B) comprising the components (B ₁ ) and (B ₂ ) is 30 by weight (component (A) / component (B)). / 70-70 / 3
0, preferably in the range of 40/60 to 60/40. If the compounding ratio is out of this range, the heat seal strength may be too strong, or the stringiness may be deteriorated, and the extrusion processability may be reduced.

Polybutene is added to the components (A) and (B).
The blending amount of polybutene-1 (C) when -1 (C) is blended has a preferable blending range depending on the blending ratio of the component (A) and the component (B). The amount is preferably 3 to 20 parts by weight, more preferably 5 to 15 parts by weight, based on 100 parts by weight in total with the component (B).

When the polybutene-1 (C) and the polypropylene (D) are blended with the components (A) and (B), the total blending amount is the blending ratio of the components (A) and (B). Although the preferred compounding range varies depending on the composition, it is desirably 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, it is desirable that 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) comprises (A) component and (B)
It is desirably used in an amount of 15 parts by weight or less, preferably 5 to 12 parts by weight, based on 100 parts by weight in total of the components.

Polybutene-1 (C) has the role of reducing the stringing phenomenon of the resin composition according to the present invention, reducing the temperature dependence of the sealing strength, and extending the temperature range in which the sealing is possible. If the amount is too large, the stringing phenomenon may be increased. Further, polypropylene (D) is effective for adjusting the sealing strength of the resin composition according to the present invention, and can reduce the sealing strength as the amount thereof is increased.
If the compounding amount is too large, the sealing strength may be too small, and the sealing property may be impaired, or the temperature dependence of the sealing strength may increase.

The melt viscosity of the ethylene-based copolymer resin composition according to the present invention can vary widely. The melt flow rate under a load of 2160 g is 0.5 to 30 g / 10 min, 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, sealing property, and high-speed thinning property. In particular, it can be suitably used as an easy-opening heat seal material. In order to use the ethylene-based copolymer resin composition of the present invention as a heat-sealing material, the above-described ethylene-based copolymer resin composition is formed as a heat-sealing layer on a base material layer and used as a laminate. Is preferred. The substrate layer used at this time may be a single layer or a multilayer, but it is preferable that the portion in contact with the heat seal layer is usually made of a thermoplastic resin or metal. In such a base material layer, a portion to be brought into contact with the heat seal layer may be subjected to a polyvinylidene chloride coating treatment, an anchor coating treatment, a corona treatment, or the like. Further, a metal such as aluminum or a metal oxide may be deposited on the base material layer.

As such a substrate, specifically, polyethylene terephthalate (PET), polyamide (P
A), polyvinyl alcohol (PVOH), ethylene
Vinyl alcohol copolymer (EVOH), polyvinylidene chloride (PVDC), polypropylene (PP), expanded polypropylene (OPP), aluminum-deposited polyethylene terephthalate (VM-PET), aluminum-deposited polypropylene (VM-PP), aluminum foil, cellophane Are used. These base layers may be multilayered as described above, and may have a configuration such as, for example, PP / PE / VM-PET.

In particular, even when stretched polypropylene (OPP), which is widely used as a packaging material, is used in a single layer or a multilayer as a substrate layer, the ethylene-based copolymer resin composition of the present invention is formed on the substrate layer. Since the packaging material obtained by forming the heat seal layer made of is heat-sealed at a low temperature, it is possible to avoid a problem that the polypropylene (PP) shrinks during heat seal. 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, since the deterioration of the contents due to oxidation and moisture absorption can be prevented.

In the present invention, the thicknesses of the base layer and the heat seal layer are arbitrary, but usually the base layer is preferably about 100 μm, and the heat seal layer is preferably about 10 to 50 μm.

Although various methods can be employed for producing the laminate having the above-described structure, the method of extrusion-coating the above-mentioned ethylene-based copolymer resin composition on the base material layer is most preferable. At this time, an anchor coat agent may be applied to the base material layer in order to increase the adhesive strength 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 use for packaging materials is in snack confectionery packaging bags, for example, stretched polypropylene / polyethylene / V
By forming the M-PET / heat-sealing layer (ethylene copolymer resin composition) in a four-layer configuration, it is possible to manufacture a packaging bag having excellent gas barrier properties, light-shielding properties, aesthetic appearance, easy-openability, and the like. it can.

When the ethylene-based copolymer resin composition according to the present invention is used as a packaging material, the heat-sealing temperature slightly varies depending on the composition of the ethylene-based copolymer resin composition used as the heat-sealing material. 120-15
It can be performed at a low temperature of about 0 ° C., and can be performed at a higher temperature if desired. Heat sealing strength is 0.4 ~
2.0 kg / 15 mm, preferably 0.8-1.2 kg / 15
mm is desirable.

When the ethylene-based 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 1 to 40.
mm, preferably 1 to 30 mm.

[0040]

When the ethylene copolymer resin composition according to the present invention is used as a heat seal layer of a multilayer packaging material, a packaging material can be produced by extrusion coating at a high processing speed. Such packaging material may be
Even when heat sealing is performed at a low temperature of about 150 ° C., high-speed bag making is possible because of the excellent hot tack property and heat sealing strength, and no bag breaking trouble occurs. In addition, since the sealing 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.

[0041]

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 thinning property when extruding and laminating the ethylene copolymer resin composition according to the present invention on a substrate, low-temperature heat sealing property of a laminate having a heat seal layer, stringing A method for evaluating the properties and low-temperature hot tack properties will be described.

[Extrusion lamination conditions] Molding machine: Laminator having a diameter of 65 mm (L / D = 3)
2) Die: Inner deckle die Die effective width: 800 mm Die opening: 0.8 × 500 mm Air gap: 110 mm Molding temperature: 305 ° C. (directly below the die) Resin extrusion amount: 930 g / 10 min (take-off speed 80 m /
Min × equivalent to 25 μm thickness of laminated resin) Taking speed: 80 m / min Substrate: Kraft paper (50 g / m ² ) (1) High-speed thinning The resin extrusion amount (930 g / min) under the above-mentioned extrusion lamination conditions is kept constant. While maintaining, the take-up speed is gradually increased from 80 m / min, and the take-up speed when the resin film starts to break is measured, and this is defined as a drawdown.

(2) Low Temperature Heat Sealability In the present invention, low temperature heat sealability was evaluated as follows. That is, a laminated film having a four-layer structure as a substrate layer [biaxially stretched polypropylene film; 20 μm / (anchor coating agent) / low density polyethylene (LDP
E); 20 μm / aluminized polyester film; 1
2 μm], the resin composition was extrusion-coated on the aluminum-evaporated polyester film surface of the base layer so as to have a thickness of 25 μm under the above-mentioned extrusion lamination conditions to produce a heat seal layer to produce a laminate.

With respect to the laminate obtained as described above, the coated heat seal layers were heated at a temperature of 120 ° C.
Heat sealed at １６０160 ° C. Heat sealing uses a single-sided heating plate type heat sealer, heat sealing conditions,
Seal width: 10 mm, seal pressure: 2 kg / cm ² , seal time: 0.5 sec., Seal bar: 30 cm × 10 mm,
From the laminate heat-sealed under these conditions, ten test pieces having a width of 15 mm and a length of 15 cm were prepared.

The maximum value of the heat seal strength of this test piece when peeled at a tensile strength of 300 mm / min and 90 ° in an atmosphere of 23 ° C. and 50% relative temperature was measured, and the average value of 10 test pieces was measured. Was used as the low-temperature heat sealability.

(3) Stringiness The stringiness 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 measurement of the low-temperature heat sealability in (2) above. .

…: Almost no fibrous material was observed on the peeled surface. Δ: Some fibrous substances are observed on the peeled surface. ×: fibrous material is observed over the entire peeled surface.

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

Hereinafter, a method for evaluating low-temperature hot tack property will be described with reference to FIG. FIG. 1 is a schematic diagram of a measuring instrument used for evaluation of low-temperature hot tack property. In FIG. 1, 1 and 2 are heat seal plates of a heat sealer used in the above-mentioned (2) evaluation of low-temperature heat sealability,
Only the upper 1 is heated to a predetermined temperature, and the lower 2 is at room temperature. Reference numerals 3a and 3b denote the test pieces described above, with the heat seal layers facing each other. This test piece 3
a, 3b are fixed at the position of the left end part 6, and the right end part is attached with 45 g of weights 4a, 4b, respectively.
b has an angle of 22.5 ° at the position of 5. The heat seal plates 1 and 2 are 30 cm long and 10 cm wide.
mm.

While maintaining the state as shown in FIG. 1, the test pieces 3a, 3b
Is heat-sealed, and at that moment, the fixing of 6 is released 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 seal surface at that time was measured, and the value was used as the low temperature hot tack property.

[0052]

Example 1 Ethyl having a methacrylic acid content of 15% by weight
Len-methacrylic acid copolymer (melt flow rate; 6
0 g / 10 min); 44 parts by weight and a methacrylic acid content of 4
Wt% ethylene-methacrylic acid copolymer (melt
Flow rate: 7 g / 10 min); 21 parts by weight and high pressure method
Low density polyethylene (melt flow rate; 10 g / 1
0 minutes, density: 0.910 g / cm^Three); 21 parts by weight
Ributene-1 (melt flow rate; 1 g / 10 min, dense
Degree: 0.910 g / cm ^Three); 4 parts by weight and polypropylene
(Melt flow rate; 6 g / 10 min, density: 0.9
10g / cm^Three); Melt blended with 10 parts by weight
A resin composition was prepared. Using this resin composition,
High-speed thinning, low-temperature heat sealing, stringing
And the low temperature hot tack property was evaluated. Table 1 shows the results
Show.

[0053]

Example 2 In Example 1, the content of methacrylic acid was 1
5% by weight of an ethylene / methacrylic acid copolymer was used in an amount of 42 parts by weight, and a methacrylic acid content of 4% by weight of ethylene / methacrylic acid was used.
Except that the amount of the methacrylic acid copolymer used was 11 parts by weight and the amount of the high-pressure low-density polyethylene was 33 parts by weight,
Performed in the same manner as in Example 1. Table 1 shows the results.

[0054]

Comparative Example 1 An ethacrylic acid having a methacrylic acid content of 15% by weight
Len-methacrylic acid copolymer (melt flow rate; 6
0 g / 10 min); 46 parts by weight, high-density low-density polyethylene
Len (melt flow rate; 10 g / 10 min, density;
0.917 g / cm^Three); 46 parts by weight and polybutene-1
(Melt flow rate: 1 g / 10 min, density: 0.91
0g / cm ^Three); 4 parts by weight and polypropylene (Meltoff)
Low rate: 6 g / 10 min, density: 0.910 g / c
m^Three); And melt blending with 4 parts by weight to prepare a resin composition.
Made. In the same manner as in Example 1 using this resin composition
Physical properties were evaluated. Table 1 shows the results.

[0055]

Comparative Example 2 An ethylene / methacrylic acid copolymer having a methacrylic acid content of 4% by weight (melt flow rate: 7 g /
10 minutes); 46% by weight and methacrylic acid content 15% by weight
An ethylene / methacrylic acid copolymer (melt flow rate; 60 g / 10 min), which is a composition obtained by melt blending 46% by weight and 8% by weight of Shell 1560 composed of a melt blend of 80% polybutene and 20% polypropylene. Prepared. Using this resin composition, physical properties were evaluated in the same manner as in Example 1.

[0056]

Comparative Example 3 The structure of an evaluation sample was 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 / aluminized polyester 12 μm / anchor coating agent / low density polyethylene (LDPE) 20 μm / unstretched polypropylene (CP
P) 25 μm (heat seal layer) The results are shown in Table 1.

[0058]

[Table 1]

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a measuring instrument used for evaluation of low-temperature hot tack property.

[Explanation of Signs] 1, 2 Heat seal plate 3a, 3b Test piece 4a, 4b Weight

Claims (7)

(57) [Claims] 1. An α, β-unsaturated carboxylic acid content of 8 to 2
30 to 70 parts by weight of ethylene / α, β-unsaturated carboxylic acid copolymer (A) which is 0% by weight, low-density polyethylene (B ₁ ), and 9% by weight of α, β-unsaturated carboxylic acid content And an ethylene / α, β-unsaturated carboxylic acid copolymer (B ₂ ) which is 6% by weight or less than the acid content of the ethylene / α, β-unsaturated carboxylic acid copolymer (A). 70 parts by weight of the combined component (B) and 3 to 20 parts by weight based on 100 parts by weight of the total of the ethylene / α, β-unsaturated carboxylic acid copolymer (A) and the polymer component (B). An ethylene copolymer resin composition comprising: polybutene-1 (C). 2. An α, β-unsaturated carboxylic acid content of 8 to 2
30 to 70 parts by weight of an ethylene / α, β-unsaturated carboxylic acid copolymer (A) which is 0% by weight, low-density polyethylene (B ₁ ), and 9% by weight of α, β-unsaturated carboxylic acid content Not more than 6% by weight of the acid content of the ethylene / α, β-unsaturated carboxylic acid copolymer (A)
70 to 30 parts by weight of a polymer component (B) composed of the ethylene / α, β-unsaturated carboxylic acid copolymer (B ₂ ) and the ethylene / α, β-unsaturated carboxylic acid copolymer (B) An ethylene copolymer resin comprising 3 to 20 parts by weight of polybutene-1 (C) and polypropylene (D) based on 100 parts by weight of the total of A) and the polymer component (B). Composition. 3. A heat seal material comprising the ethylene-based 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. A base material layer comprising 30 to 70 parts by weight of an ethylene / α, β-unsaturated carboxylic acid copolymer (A) having an α, β-unsaturated carboxylic acid content of 8 to 20% by weight; Low-density polyethylene (B ₁ ) having an α, β-unsaturated carboxylic acid content of 9% by weight or less and 6% by weight of the acid content of the ethylene / α, β-unsaturated carboxylic acid copolymer (A)
70 to 30 parts by weight of a polymer component (B) composed of the ethylene / α, β-unsaturated carboxylic acid copolymer (B ₂ ) and the ethylene / α, β-unsaturated carboxylic acid copolymer (B) It is characterized in that an ethylene copolymer resin composition comprising 3 to 20 parts by weight of polybutene-1 (C) is laminated on 100 parts by weight of the total of A) and the polymer component (B). Laminate. 6. A base material layer comprising 30 to 70 parts by weight of an ethylene / α, β-unsaturated carboxylic acid copolymer (A) having an α, β-unsaturated carboxylic acid content of 8 to 20% by weight, Low-density polyethylene (B ₁ ) having an α, β-unsaturated carboxylic acid content of 9% by weight or less and 6% by weight of the acid content of the ethylene / α, β-unsaturated carboxylic acid copolymer (A)
70 to 30 parts by weight of a polymer component (B) composed of the ethylene / α, β-unsaturated carboxylic acid copolymer (B ₂ ) and the ethylene / α, β-unsaturated carboxylic acid copolymer (B) 3 to 20 parts by weight of an ethylene copolymer resin composition comprising polybutene-1 (C) and polypropylene (D) is laminated on 100 parts by weight of the total of A) and the polymer component (B). A laminate comprising: 7. A packaging material comprising the laminate according to claim 5 or 6.