JPH08208895A - Resin composition - Google Patents

Abstract

PURPOSE: To obtain a resin composition suitable for producing stretch packaging films good in appearance, rich in flexibility and excellent in deformation recovery. CONSTITUTION: This resin composition comprises (A) 70-97wt.% of at least one kind of thermoplastic resin selected from low-density polyethylene, ethylene-α-olefin copolymers, ethylene-vinyl acetate copolymers, ethylene-(meth) acrylic acid copolymers, ethylene-(meth)acrylic alkyl ester copolymers, copolymers each obtained by neutralizing with a metallic component a copolymer of ethylene and a carboxyl-bearing monomer, polypropylene and polybutene-1 and (B) 30-3wt.% of a copolymerized oligomer 100-5000 in number- average molecular weight made from ethylene and a 3-20C α-olefin.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to improvements in resin compositions. More specifically, the present invention relates to a resin composition suitable for production of a stretch packaging film having a good appearance, flexibility, and excellent recovery from deformation.

[0002]

2. Description of the Related Art Stretch packaging is known as one of the forms for pre-packing various foods such as fruits and vegetables, fresh fish, meat, and prepared foods, and these foods are placed directly or on a plastic tray. Will be wrapped in. recent years,
As a film used for such stretch packaging, due to environmental issues, etc., instead of conventional polyvinyl chloride,
Low density polyethylene, ethylene-vinyl acetate copolymer,
Films made of linear low-density polyethylene-based resins have come to be used.

However, these conventionally used films have a problem in that they are inferior in quality in terms of appearance, flexibility, and deformation recovery and cannot be packaged with commercial value. For example, JP-A-3-86544 discloses a linear low-density polyethylene resin (ethylene-butene-1-hexene-) having a density of 0.910 g / cm ³ or less.
Although a stretch wrapping film using a (1 copolymer) has been proposed, this is not satisfactory because the recovery rate for appearance and deformation is insufficient.

[0004]

DISCLOSURE OF THE INVENTION The present invention is intended to solve the above-mentioned problems of the prior art, and is intended for the production of a stretch packaging film having a good appearance, excellent flexibility, and excellent recovery from deformation. The purpose is to provide a suitable resin composition.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention have determined that the specific thermoplastic resin (A) and the copolymerization oligomer (B) specified in the present invention are combined. The present invention has been completed based on the finding that the above-mentioned object of the present invention can be achieved by a resin composition containing a specific ratio.

In the present invention, therefore, in order to solve the above problems, low density polyethylene, ethylene-α-olefin copolymer, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, Group consisting of ethylene- (meth) acrylic acid alkyl ester copolymer, copolymer obtained by neutralizing a copolymer of ethylene and a monomer having a carboxyl group with a metal component, polypropylene, and polybutene-1 70-97% by weight of at least one thermoplastic resin (A) selected from the above, and a number-average molecular weight of 100-5000, and a copolymerized oligomer of ethylene and an α-olefin having 3 to 20 carbon atoms ( Measures are taken to obtain a resin composition containing 30 to 3% by weight of B).

In a preferred embodiment of the present invention,
As the copolymer oligomer (B), JIS K 228
The kinematic viscosity at 100 ° C. measured according to 3 is 100.
Measures are taken to make a resin composition using one that is 0 centistokes or less.

The present invention will be described in detail below. The thermoplastic resin (A) used in the present invention is low density polyethylene, ethylene-α-olefin copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid alkyl ester copolymer. Copolymer, a copolymer obtained by neutralizing a copolymer of ethylene and a monomer having a carboxyl group with a metal component (hereinafter,
It is called "ionomer". ), Polypropylene, and polybutene-1. At least one thermoplastic resin selected from the group consisting of:

Low density polyethylene has a density of 0.9.
It is preferably 1 to 0.94 g / cm ³ . Ethylene
The α-olefin copolymer has an ethylene component of 75
To 99% by weight and an α-olefin component in the range of 25 to 1% by weight, and the α-olefin has 3 to 20 carbon atoms, preferably 3 to 12, and more preferably 3 to 12.
8 (propylene, butene-1, hexene-1, 4,
-Methylpentene-1, octene-1 and the like). Of these, the density is 0.91 to 0.94 g / cm
³ in the range of what is said to as linear low density polyethylene, also a density of the range of 0.89~0.91g / cm ³ is also referred to as linear very low density polyethylene.

As the ethylene-vinyl acetate copolymer,
The vinyl acetate component content is preferably 5 to 25% by weight. As the ethylene- (meth) acrylic acid copolymer,
Acrylic acid component or methacrylic acid component content is 3 to 20
Weight% is preferable. The ethylene-methyl (meth) acrylate copolymer preferably has a methyl acrylate component or methyl methacrylate component content of 10 to 28% by weight.

As the ionomer, ethylene and a monomer having a carboxyl group such as methacrylic acid or acrylic acid, and 5 to 20% by weight of a monomer having a carboxyl group is used.
As a raw material, a copolymer obtained by approximately polymerizing is used as a metal component, for example, a hydroxide such as sodium hydroxide or aluminum hydroxide, an alcoholate such as sodium methylate, or sodium acetate, zinc acetate or sodium propionate. Copolymers obtained by neutralizing most of the acid groups with fatty acid metal salts such as

As the polypropylene, in addition to the propylene homopolymer, 60 to 99.5% by weight of the propylene component is used.
In the range of 40 to 0.5% by weight, and the balance (40 to 0.5% by weight) of ethylene and / or carbon number is 4 to 20, preferably 4 to
12, more preferably a copolymer of 4 to 8 α-olefins. Further, polybutene-1 can be used as well. These may be used alone or as a mixture of two or more kinds.

Copolymerization oligomer used in the present invention
(B) is a copolymerized oligomer having a number average molecular weight of 100 to 5,000 and ethylene and an α-olefin having 3 to 20 carbon atoms. The α-olefin copolymerized with ethylene in the production of the copolymerization oligomer (B) is
There is no particular limitation as long as it has 3 to 20 carbon atoms. Specific examples of α-olefins that can be used include propylene and
Butene-1, pentene-1, hexene-1, 4-methylpentene-1, 3-methyl-1-pentene, octene-
1, decene-1, dodecene-1, tetradecene-1, hexadecene-1, octadecene-1 and the like. These α-olefins may be used alone or in combination of two or more. Good.

The copolymer oligomer (B) has a number average molecular weight of 100 to 5,000, preferably 200 to 300.
0, more preferably 300 to 2,000 is used. If the number average molecular weight is less than 100, bleeding out to the surface of the film is severe and stickiness occurs, and it is difficult to use. If it is more than 5000, the viscosity is high, so bridging occurs in the feed hopper during molding and the screw This is because there will be a problem that the supply to the

The copolymerization oligomer (B) can be produced, for example, by a known method described in JP-A-1-104695. For example, a catalyst formed from a soluble vanadium compound and an organoaluminum compound in the presence of hydrogen. Can be obtained by continuously copolymerizing ethylene and α-olefin in the liquid phase. At this time, the concentration of vanadium compound supplied to the polymerization system was 0.3 mmol or more per liter of liquid phase, and the amount of the aluminum compound supplied to the polymerization system was 5 times or less the concentration of vanadium compound of the polymerization system. It is diluted with a medium and supplied.

As the vanadium compound, VOCl₃,
VO (OC₂H_Five) Cl₂, VO (OC ₂H_Five)_1.5C
l_1.5, VCl_FourAs in the general formula VO (OR)_nX_3-nAlso
Is VX_Four(However, R is an aliphatic hydrocarbon group, X is a halogen
And a compound represented by 0 ≦ n ≦ 3) can be used.
As the organoaluminum compound, (C₂H_Five)₃A
l, (C₂H_Five)₂AlCl, (C₂H_Five)_1.5AlC
l_1.5, (IsoC_FourH₉)_1.5AlCl _1.5, (C₂H_Five)
AlCl₂, Or a general formula R such as a mixture thereof_mA
l_3-m(However, R is an aliphatic hydrocarbon group, X is a halogen
The compounds represented by 1 ≦ m ≦ 3) can be used.

As the polymerization medium, pentane, hexane,
Charcoal like heptane, kerosene, cyclohexane, toluene
Hydrogen fluorides can be used. Vanadium compound concentration in liquid phase
Is 0.3 mmol / liter or more, preferably 0.5
In the liquid phase.
Organoaluminum compound concentration is Al / V (atomic ratio)
The range is 2 to 50, especially 3 to 20. Also, polymerization reaction
The applicable conditions are usually a temperature of 0 to 100 ° C. and a pressure of 0 to 50 k.
g / cm ²Range, average residence time 5 to 300 minutes
Selected from.

Further, such an ethylene-α-olefin copolymerization oligomer is commercially available from Mitsui Petrochemical Co., Ltd. under the trade name of "Lucant" and is used as the copolymerization oligomer (B). be able to.

The resin composition of the present invention contains 70 to 97% by weight of the above-mentioned thermoplastic resin (A), a copolymerization oligomer (B).
In an amount of 30 to 3% by weight. Copolymerization oligomer
When the content of (B) is less than 3% by weight, the film obtained from this resin composition is inferior in appearance characteristics such as haze and gloss, and is also poor in the effect of improving flexibility. When the amount is larger, the resulting film has excellent appearance and flexibility, but the oligomer bleeds out to the surface of the film, causing a problem of stickiness on the film, which is not preferable. From such a viewpoint, the preferable contents of the thermoplastic resin (A) and the copolymerization oligomer (B) are 75 to 97% by weight and 25 to 3% by weight, particularly 80 to 95% by weight and 20 to 5% by weight. Is.

In order to improve the impact strength of the film obtained from the resin composition of the present invention, a rubber component can be added within the range not impairing the transparency of the film. Typical examples of rubber that can be added include hydrogenated styrene-butadiene-styrene copolymer rubber and ethylene-
Propylene copolymer rubber, ethylene-butene-1 copolymer elastomer, 1,2-polybutadiene, ethylene-
Examples thereof include propylene-ethylidene norbornene copolymer rubber and the like. The amount of addition at that time depends on the kind of rubber, but is generally 0.5 to 20% by weight, preferably 2-1.
It is preferably 8% by weight, more preferably 5 to 15% by weight.

Further, the resin composition of the present invention is imparted with appropriate slipperiness, self-adhesiveness, antifogging property and antistatic property to the obtained film to improve suitability for an automatic packaging machine. , A small amount of an aliphatic alcohol-based aliphatic ester, which is a compound of an aliphatic alcohol having 1 to 12 carbon atoms, preferably 1 to 6 and a fatty acid having 10 to 22 carbon atoms, preferably 12 to 18 carbon atoms, is added. can do. Specific examples of the ester that can be added include monoglycerin oleate, polyglycerin ricinoleate, glycerin triricinoleate, glycerin acetyl ricinoleate, methyl acetyl ricinoleate, ethyl acetyl ricinoleate, butyl acetyl ricinoleate, pentaerythritol oleate, polyethylene. Examples thereof include glycol oleate, polypropylene glycol oleate, polyoxyethylene glycerin, polyoxypropylene glycerin, sorbitan oleate, solibitan laurate, polyethylene glycerin sorbitan oleate, polyethylene glycol sorbitan laurate and the like.

In addition to esters, polyalkylene ether polyols such as polyethylene glycol and polypropylene glycol, epoxidized soybean oil, polyoxyethylene alkylamine fatty acid esters, polyoxyethylene alkyl phenyl ethers, arylic acid amides, stearic acid amides, C12-C22 higher fatty acid amides such as erucic acid amide, ethylenebisstearic acid amide, ethylenebisoleic acid amide, polyethylene wax, polypropylene wax,
The same effect can be obtained by blending 0.5 to 5% by weight of at least one of liquid paraffin, castor oil derivative, low molecular weight sticky substance of polybutene, terpene resin and petroleum resin.

From the resin composition of the present invention having the above-mentioned constitution, various films having good appearance characteristics such as haze and gloss, rich flexibility and excellent deformation recovery can be obtained. The film can be preferably used as a film for stretch packaging. The film obtained from the resin composition of the present invention includes a monolayer film made of only the resin composition of the present invention and a laminated film.

In the case of a laminated film, at least (a) a laminated film having a two-layer structure or a three-layer structure composed of the resin compositions of the present invention having different compositions, and (b) at least a layer composed of the resin composition of the present invention. Linear ultra low density polyethylene, ethylene-vinyl acetate copolymer resin, ethylene-
(Meth) acrylic acid copolymer resin, ethylene- (meth)
A laminated film having a two-layer or three-layer structure provided with a layer made of an acrylic acid alkyl ester copolymer resin or the like can be used. It is particularly preferable to provide a layer made of an ethylene-vinyl acetate copolymer because the laminated film (b) has excellent transparency and adhesiveness.

Further, in the laminated film of (b), the resin laminated on the layer comprising the resin composition of the present invention also improves the flexibility, deformation recovery and antifogging property of the obtained film. It is preferable to contain the above-mentioned copolymerization oligomer (B), rubber, and / or aliphatic alcohol fatty acid ester.

The preferred layer structure of the laminated film is illustrated below. (1) On one or both sides of the layer (a1) comprising 70 to 97% by weight of low-density polyethylene and 30 to 3% by weight of a copolymer oligomer (B), ethylene of 75 to 95% by weight, vinyl acetate, and aliphatic Monomer 25 selected from saturated carboxylic acid and aliphatic unsaturated monocarboxylic acid alkyl ester
Up to 5% by weight of a copolymer or an ionomer layer (b1).

(2) Linear low density polyethylene 70-9
A layer obtained by laminating the above layer (b1) on one side or both sides of the layer (a2) consisting of 7% by weight and 30 to 3% by weight of the copolymer oligomer (B). (3) The above layer (b1) was laminated on one side or both sides of the layer (a3) comprising 70 to 97% by weight of a linear ultra-low density polyethylene resin and 30 to 3% by weight of a copolymer oligomer (B). thing.

(4) A layer (b1) laminated on one side or both sides of a layer (a4) comprising 70 to 97% by weight of a polypropylene resin and 30 to 3% by weight of a copolymer oligomer (B). (5) Layer (a5) comprising linear low-density polyethylene or linear ultra-low-density polyethylene 50 to 92% by weight, propylene resin 5 to 40% by weight, and copolymer oligomer (B) 30 to 3% by weight. On one or both sides of the above layer (b
A stack of 1).

(6) 10 to 87% by weight of butene-1 resin, olefin resin (excluding butene-1 resin) and / or olefin thermoplastic elastomer 87-1
A layer obtained by laminating the layer (b1) on one side or both sides of the layer (a6) consisting of 0% by weight and 30 to 3% by weight of the copolymer oligomer (B). (7) Layer (a7) comprising 70 to 97% by weight of low density polyethylene resin and 30 to 3% by weight of copolymer oligomer (B).
A layer (b2) made of linear low-density polyethylene or linear ultra-low density polyethylene is laminated on one side or both sides of. (8) A layer in which the layer (b2) is laminated on one side or both sides of the layer (a4).

In the resin composition of the present invention, the above-mentioned thermoplastic resin (A) and copolymer oligomer (B) are blended in respective predetermined weight ratios, or if necessary, a small amount of rubber or aliphatic alcohol is added thereto. It can be easily obtained by adding and blending a carboxylic acid ester. Further, if the compounded resin composition is further heated and melted to form a pelletized composition, the subsequent handling is easy.

When a single-layer film or a laminated film for stretch packaging is produced from the resin composition of the present invention as a raw material, known methods such as a T-die method or an inflation method using a single-layer die or a multi-layer die are used. A film forming method may be used, and the thickness of the film at that time is usually 5 to 30 μm.
In the laminated film, the thickness of the layer (a) made of the resin composition of the present invention is 2 to 10 μm, and the thickness of the layer (b) laminated on this layer is 3 to 10 μm.

[0032]

EXAMPLES Next, the present invention will be described more specifically by way of examples, but the present invention is not limited to the description of these examples unless it exceeds the gist. In the following description, “%” means weight basis unless otherwise specified.

(1) First, the following were prepared as the thermoplastic resin (A) and the copolymerization oligomer (B). Thermoplastic resin (A); Thermoplastic resin A-: the butene component content is 10%, the hexene component content is 20%, and the density is 0.910 g /
cm3, melt flow rate at 190 ° C (MF
R-) is 1.0 g / 10 min ethylene-butene-
1-hexene-1 copolymer thermoplastic resin A-: vinyl acetate component content is 15%, MFR at 190 ° C. is 2.0 g / 10 min
Ethylene-vinyl acetate copolymer thermoplastic resin A-: 4-methylpentene-1 component content is 11%, and the density is 0.910 g / cm3, 19
Copolymer with ethylene-4-methylpentene-1 having an MFR at 0 ° C of 3.6 g / 10 min Thermoplastic resin A-: ethylene component content is 1.7%,
The butene-1 component content is 12.5% and the density is 0.
898g / cm3, MFR at 230 ° C is 5.5g
/ 10 min propylene-ethylene-butene-1
Copolymer

Copolymerization oligomer (B); Copolymerization oligomer B-: number average molecular weight is about 400, kinematic viscosity at 100 ° C is 10 centistokes ethylene-propylene copolymerization oligomer Copolymerization oligomer B-: number average An ethylene-propylene copolymer oligomer having a molecular weight of about 1000 and a kinematic viscosity at 100 ° C. of 40 centistokes.

(2) The films obtained in the respective examples and comparative examples were evaluated by the following methods. Haze: Measured according to JIS K 6714. Gloss: Measured according to JIS Z 8741 (20 degrees). Tensile modulus: Measured according to ISO R 1184. Deformation recoverability: The device shown in FIG. 1 was used. The film (f) is fixed to the upper edge of the film-fixing cylindrical jig (2) having an inner diameter of 100 mm mounted on the load cell (1) by the fixing frame (3), and the tip has a hemispherical shape with a diameter of 20 mm. After pushing the piston rod (4) at a speed of 50 mm / min so as to give a constant strain (H) to the center of the fixed film, the piston rod (4) is retracted to generate the piston rod on the film. The strain amount (mm) at which the strain due to (4) disappears within 3 minutes is defined as the "deformation recovery amount". Bleed-out property: The obtained monolayer film or laminated film was left in an oven kept at 50 ° C. for 48 hours, then judged by touch, and displayed according to the following criteria. ◯: No stickiness was felt ×: Stickiness was felt

Example 1 Thermoplastic resin A-95% and copolymerized oligomer B-5
% Was kneaded at 165 ° C. using a twin-screw extruder having a diameter of 30 mmφ to obtain a pellet-shaped resin composition. Then, using the obtained resin composition, a caliber of 50 mmφ, L
/ D25 extruder has a diameter of 50 mm at the tip and a lip width of 1.
Using a device equipped with a 0 mm annular single layer forming die, a temperature of 1
Melt extrusion at 75 ° C, blow ratio 10.0, take-up speed 15
A film having a thickness of 20 μm shown in Table 1 below was manufactured by inflation molding under the condition of m / min. With respect to the obtained film, various properties such as appearance (haze degree, glossiness), tensile modulus, deformation recovery property, and bleed-out property were measured and evaluated according to the methods described above. The results are shown in Table 2 below.

Examples 2 to 3 and Comparative Examples 1 to 3 In the examples described in Example 1, the proportions of the thermoplastic resin A- and the copolymerization oligomer B- were changed as shown in Table 1, respectively. A pellet-shaped resin composition was obtained in the same manner as in the example except that the above-mentioned procedure was performed, and a film having a thickness shown in Table 1 was produced from the resin composition. For each film obtained,
Various characteristics similar to those in the example were measured and evaluated. The results are also shown in Table 2.

Example 4 A pelletized resin was prepared in the same manner as in Example 1 except that the thermoplastic resin A- was used instead of the thermoplastic resin A- used in the same example. A composition was obtained, and a film having a thickness shown in Table 1 was produced from the resin composition. With respect to the obtained film, various properties similar to those in the example were measured and evaluated. The results are also shown in Table 2.

Example 5 A pelletized resin was prepared in the same manner as in Example 1 except that the copolymer oligomer B- was used instead of the copolymer oligomer B- used in the same example. A composition was obtained, and a film having a thickness shown in Table 1 was produced from the resin composition. With respect to the obtained film, various properties similar to those in the example were measured and evaluated. The results are also shown in Table 2.
Shown in

Comparative Example 4 In the example described in Example 1, the resin composition comprising the thermoplastic resin A- and the copolymerization oligomer B- was not used,
A film having a thickness shown in Table 1 was produced using a resin which was composed of only the thermoplastic resin A- and did not contain the copolymerized oligomer (B) at all. With respect to the obtained film, various properties similar to those in the example were measured and evaluated. The results are also shown in Table 2.

[0041]

[Table 1]

[0042]

[Table 2]

From the above results, from the resin composition satisfying the requirements of the present invention, the haze and gloss are good, the appearance characteristics are excellent, the tensile elastic modulus is large, the flexibility is excellent, and the deformation recovery is excellent. In addition, films having excellent bleed-out properties are obtained (Examples 1 to 5), whereas from the resin compositions that do not satisfy the requirements of the present invention, films having poor gloss and poor recovery from deformation ( It is clear that only Comparative Examples 1 and 2), a film having a small tensile elastic modulus and poor bleed-out properties (Comparative Example 3), or a film having a poor gloss (Comparative Example 4) can be obtained.

Example 6 By the method described in Example 1, the thermoplastic resin A-90 was used.
% And copolymer oligomer B-10% to obtain a pellet-shaped resin composition for the layer (a). Next, caliber 65 mm
Diameter that allows co-extrusion of resin extruded from two extruders, φ, L / D25 extruder (first extruder) and extruder with 50 mmφ, L / D25 extruder (second extruder). The resin composition for the layer (a) was extruded from the first extruder under the condition of 175 ° C. using an apparatus equipped with an annular three-layer molding die having a diameter of 50 mm and a lip width of 1.0 mm, and was extruded from the second extruder to 16
By extruding the thermoplastic resin A-for the layer (b) under the condition of 5 ° C., the layer structure is b / n as shown in Table 3 below.
A laminated film having a / b / and a thickness of each layer and a total thickness as shown in Table 3 was produced. Various properties of the obtained laminated film were measured and evaluated in the same manner as in Example 1. The results are shown in Table 4 below.

Comparative Example 5 In the same manner as in Example 6, except that the resin excluding the copolymerized oligomer (B), which was composed of only the thermoplastic resin A-, was extruded from the first extruder. Then, a laminated film as shown in Table 3 was produced. With respect to the obtained laminated film, various properties similar to those in the example were measured and evaluated. The results are also shown in Table 4.

Example 7 By the method described in Example 1, the thermoplastic resin A-90 was used.
% And copolymer oligomer B-10% to obtain a pellet-shaped resin composition for the layer (a). Then, in the example described in Example 6, except that the resin composition for the layer (a) was extruded from the first extruder, in the same manner as in the same example,
Laminated films as shown in Table 3 were produced. With respect to the obtained laminated film, various properties similar to those in the example were measured and evaluated. The results are also shown in Table 4.

Example 8 By the method described in Example 1, the thermoplastic resin A-90 was used.
% And copolymer oligomer B-10% to obtain a pellet-shaped resin composition for the layer (a). Then, in the example described in Example 6, except that the resin composition for the layer (a) was extruded from the first extruder, in the same manner as in the same example,
Laminated films as shown in Table 3 were produced. With respect to the obtained laminated film, various properties similar to those in the example were measured and evaluated. The results are also shown in Table 4.

Comparative Example 6 In the same manner as in Example 6, except that the resin excluding the copolymerized oligomer (B) which was composed of only the thermoplastic resin A-was extruded from the first extruder. Then, a laminated film as shown in Table 3 was produced. With respect to the obtained laminated film, various properties similar to those in the example were measured and evaluated. The results are also shown in Table 4.

[0049]

[Table 3]

[0050]

[Table 4]

From the above results, a laminated film in which a layer composed of a resin composition satisfying the requirements of the present invention is used as a central layer and ethylene-vinyl acetate copolymer is laminated on both surfaces of the central layer, the appearance characteristics, and the tensile modulus of elasticity are obtained. , The deformation recovery property, and the bleed-out property are generally good, while the laminated film having a layer composed of a resin composition which does not satisfy the requirements of the present invention as a central layer has a glossiness (Comparative Example 5) and It is clear that the deformation recovery (Comparative Example 6) is inferior.

[0052]

INDUSTRIAL APPLICABILITY The present invention can provide a resin composition suitable for production of a film for stretch wrapping. From this resin composition, excellent appearance characteristics such as haze and glossiness and excellent flexibility are provided. The advantageous effect that a stretch packaging film having excellent deformation recovery can be produced.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an apparatus used for measuring deformation recovery of a resin film.

[Explanation of symbols]

 1: Load cell 2: Cylindrical jig for fixing film 3: Fixing frame 4: Piston rod f: Film H: Strain

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Motohiro Seki 1 Toho-cho, Yokkaichi-shi, Mie Mitsubishi Chemical Co., Ltd. Yokkaichi Research Institute

Claims (2)

[Claims] 1. A low density polyethylene, an ethylene-α-olefin copolymer, an ethylene-vinyl acetate copolymer, an ethylene- (meth) acrylic acid copolymer, an ethylene- (meth) acrylic acid alkyl ester copolymer, At least one thermoplastic resin selected from the group consisting of a copolymer obtained by neutralizing a copolymer of ethylene and a monomer having a carboxyl group with a metal component, polypropylene, and polybutene-1 (A 70 to 97% by weight, and a number average molecular weight of 100 to 5000, and 30 to 3% by weight of a copolymerization oligomer (B) of ethylene and an α-olefin having 3 to 20 carbon atoms. And a resin composition. 2. The copolymerization oligomer (B) according to JIS
The resin composition according to claim 1, wherein the kinematic viscosity at 100 ° C. measured according to K 2283 is 1000 centistokes or less.