JP3149578B2 - Wrap film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wrapping film used for food packaging and the like. More specifically, the present invention relates to a wrap film excellent in cutability, transparency, heat resistance, interlayer adhesion, barrier properties, non-heat shrinkage, food safety, environmental suitability and productivity.

[0002]

2. Description of the Related Art Conventionally, as a wrapping film used for food packaging, a film mainly composed of polyvinylidene chloride, polyethylene or polyvinyl chloride is known.

[0003]

However, polyvinylidene chloride-based films have a disadvantage that shrinkage upon heating is large, and polyethylene-based films come in contact with oily substances (for example, meat and tempura) and have high heat. In this case, there is a disadvantage that the film is melted, and there is a problem that the polyvinyl chloride-based film causes a whitening phenomenon when brought into contact with boiling hot water.

On the other hand, as a resin used for a wrapping film, an ethylene-vinyl alcohol copolymer resin (hereinafter referred to as "E
VOH "). Although this resin has excellent transparency and gas barrier properties,
Because of high hygroscopicity, it is difficult to maintain the original physical properties of a single-layer film. Further, such a wrapping film has the following problems in cutability (easiness of cutting). That is, the wrapping film is usually stored in a case such as a paper tube, and the "saw blade"
The film is pulled against a cutting blade called "cutting blade" and cut into appropriate lengths.

[0005] As a "saw blade" used for cutting a film, a simple blade which is generally obtained by punching an iron plate having a thickness of about 0.2 mm into a saw shape is used. For cases that support
A coated cardboard paper box of about 0 g / m ² is used, and the rigidity is extremely low. This kind of film is required to be easily cut according to the user's will even with such a simple cutting mechanism, but in reality, the case and the "saw blade" are only deformed. Instead, the film may be deformed, or cutting may occur at a position outside the “saw blade”. Specifically, the conventional polyvinylidene chloride-based film, when a tear is formed in a part of the film at the time of cutting, the tear spreads,
There is a tendency to cut diagonally without being cut along the "saw blade". Further, the conventional polyethylene-based film requires a considerable tensile force at the time of cutting, so that not only the case is bent but also the film may be deformed.

[0006]

Means for Solving the Problems The inventor of the present invention has made intensive studies to produce a wrapping film in which the above-mentioned problems of the conventional wrapping film have been solved, and as a result, a polyolefin resin has been used on both sides of the EVOH layer. What was laminated by extrusion method,
By stretching the film in the take-off direction, the above-mentioned problems are solved, and the cut property, heat resistance, interlayer adhesion, and non-heat shrinkage can be achieved without impairing the inherent properties (gas barrier property and transparency) of EVOH. The present inventors have found that a wrap film excellent in environmental suitability and food safety can be obtained.

Namely gist of the present invention, on both sides of a layer made of EVOH, and an acid-modified polyolefin resin and the EVOH via an adhesive layer formed by melt-mixing, a layer made of a polyolefin resin, in the longitudinal direction 2 Stretch at up to 6 times draw ratio
The total thickness is 2 to 50 μm, and ethylene-vinyl
Of the layer made of alcohol copolymer resin
It consists in wrapping film, characterized in that 10 to 90%. Hereinafter, the present invention will be described in detail. The wrapping film of the present invention has at least five or more layers, for example, five layers of an outer layer (surface layer) / adhesive layer / center layer / adhesive layer / inner layer (surface layer).

The polyolefin resin constituting the outer layer and the inner layer of the wrapping film includes polypropylene, polyethylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-butene 1 copolymer and the like. In particular, a polypropylene resin is preferably used. The type of the polypropylene resin is not particularly limited, and may be a propylene homopolymer or a copolymer of ethylene or the like and propylene. Examples of the propylene homopolymer include isotactic polypropylene, syndiotactic polypropylene, and atactic polypropylene, and isotactic polypropylene is particularly preferable. Further, the copolymer of propylene and other components such as ethylene may be any of a random copolymer and a block copolymer. For example, a random or block copolymer of propylene and a random or block copolymer or propylene and 1 to 10 wt% of C ₄ or more α- olefins with 1-5 wt% of ethylene. The physical properties of the polypropylene-based resin may be selected according to various uses, conditions, and the like, but are usually 0.5 to 30 g / 10 min, preferably 2 to 15 g / 10 min . Density 0.89 ~ 0.91g /
cm ³ is preferred. Melt flow rate is JI
Measured at 230 ° C. under a load of 2.16 kg according to SK6758.

[0009] Homopolymers and copolymers in the case of using a polyethylene - polymer either well, co - random or block copolymer of ethylene and 1 to 10 wt% of propylene or C ₄ or more α- olefins used as the polymer Can be Among them, the MFR at 190 ° C. is 0.5 to 30 g / 10 min, preferably 1.5 to 15 g / min.
Ten minutes is desirable from the viewpoint of moldability.

[0010] The layers (for example, the inner layer and the outer layer) formed from the polyolefin-based resin composition are joined to a central layer formed from an ethylene-vinyl alcohol copolymer resin via an adhesive layer. Such ethylene-vinyl alcohol copolymer resins usually have an MFR of 1 to 20 g / 1.
0 min (230 ° C.) is used. In addition, from the viewpoint of moldability, it is preferably 1 to 10 g / 10 min, more preferably 2 to 7 g / 10 min. MFR is 1g
If it is less than / 10 minutes, the extrudability is poor, and if it exceeds 20 g / 10 minutes, the film-forming stability decreases. Further, the ethylene content in the ethylene-vinyl alcohol copolymer resin also greatly affects the performance, and is preferably 20 to 60 mol%, more preferably 25 to 50 mol%.

When the content is less than 20 mol%, problems occur in water resistance and extrudability, and when it exceeds 50 mol%, the barrier properties and transparency deteriorate. The adhesive layer of the present invention uses a material obtained by melting and mixing an acid-modified polyolefin resin and EVOH. The acid-modified polyolefin resin can be obtained by subjecting a polyolefin resin as a base to a graft reaction with an acid such as an unsaturated carboxylic acid or a derivative thereof by an arbitrary method.

For example, a method of reacting a polyolefin with an unsaturated carboxylic acid in a molten state (for example, Japanese Patent Publication No.
3-27421), a method of reacting in a solution state (for example, Japanese Patent Publication No. 44-15422), a method of reacting in a slurry state (for example, Japanese Patent Publication No. 43-18144), a method of reacting in a gas phase state (for example, 50-77493
No.). Among these methods, the melt kneading method using an extruder is preferably used because of its simple operation.

As a raw material of the acid-modified polyolefin resin, for example, polyethylene, polypropylene and the like are used. The resin is not particularly limited, and homopolymers and co-polymers of polyethylene and polypropylene are used. The range of the preferable physical properties of these polymers is preferably the same as that of the polyolefin used for the inner and outer layers described above.

Moreover, it is preferable to use the same raw material as the inner and outer layers from the viewpoint of the adhesive force between the inner and outer layers and the adhesive layer and the formability.
As the unsaturated carboxylic acids used for modifying the polyolefin of the adhesive layer, for example, acrylic acid, methacrylic acid,
Maleic acid, fumaric acid, itaconic acid, citraconic acid, or their anhydrides, esters, amides, imides, metal salts, and the like. Of these, maleic anhydride is most preferably used.

An organic peroxide is used to accelerate the reaction between the polyolefin and the unsaturated carboxylic acids.
Examples of the organic peroxide include benzoyl peroxide, lauroyl peroxide, azobisisobutyronitrile, dicumyl peroxide, α, α′-bis (t-butylperoxydiisopropyl) benzene,
2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, di-t-butylperoxide, Cumene hydroperoxide, t-butyl hydroperoxide and the like. The amount of the organic peroxide to be added is not particularly limited, but is usually 0.005 to 5 parts by weight, preferably 0.01 to 1 part by weight, per 100 parts by weight of the polyolefin.

The acid-modified polyolefin resin grafted with an unsaturated carboxylic acid is selected from the polyolefins shown above,
The unsaturated carboxylic acid and the organic peroxide are sufficiently mixed by a tumbler, a Henschel mixer, or the like, and the mixture is melt-kneaded at a temperature higher than the melting point of the polyolefin, generally higher than the melting point and lower than 280 ° C. to perform the grafting reaction. The method of melt-kneading is not particularly limited, and can be performed using, for example, a screw extruder, a Banbury mixer, a mixing roll, or the like. However, a screw extruder is preferably used for simplicity of operation. The temperature and time of the melt-kneading vary depending on the decomposition temperature of the organic peroxide used.
To 280 ° C. for 0.3 to 30 minutes, preferably 170
1 to 10 minutes at ~ 250 ° C is appropriate.

The amount of the unsaturated carboxylic acid grafted in the acid-modified polyolefin resin is 0.01 to 3% by weight, preferably 0.03 to 1% by weight. When the amount of the unsaturated carboxylic acid grafted is 0.01% by weight or less, the adhesiveness decreases,
If the content is 3% by weight or more, the amount of gelled matter tends to increase, which is not preferable. In the present invention, the acid-modified polyolefin resin desirably contains an elastomer, preferably 2% by weight or more, preferably 5 to 50% by weight, particularly preferably 1% by weight.
By containing 0 to 25% by weight of the acid-modified polyolefin elastomer, the adhesiveness can be improved.

Examples of the raw material for the acid-modified polyolefin elastomer include ethylene and α having 3 or more carbon atoms.
-Copolymer elastomers with olefins are used. Among them, the density is less than 0.91 g / cm ³ , preferably 0.1 g / cm ³ .
85 to 0.90 g / cm ³ and MFR of 0.1 to 50 g
/ 10 minutes (ASTM-D1238, 190 ° C.), preferably 1 to 20 g / 10 minutes.

Α having 3 or more carbon atoms to be copolymerized with ethylene
Examples of the olefin include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, and the like, together with non-conjugated dienes such as 1,4-hexadiene, dicyclopentadiene, and ethylidene norbornene. Can also be used. The ethylene-α-olefin copolymer elastomer is obtained by copolymerizing ethylene and α-olefin with a Ziegler-type catalyst, in particular, a catalyst composed of a vanadium compound such as vanadium oxytrichloride and vanadium tetrachloride and an organoaluminum compound. It is desirable that the ethylene content in the elastomer is in the range of 40 to 90 mol% and the α-olefin content is in the range of 10 to 60 mol%. Commercially available ethylene-α-olefin copolymer elastomers include, for example, CdF Chimie
E. FIG. P. NORSOFLEX (FW1600, F
W1900, MW1920, SMW2440, LW22
20, LW2500, LW2550); Flex resin (DFDA1137, DFDA11) of Nippon Unicar
38, DEFD1210, DEFD9042); Tuffmer (A4085, A4090, P01) manufactured by Mitsui Petrochemical Co., Ltd.
80, P0480), JSR-EP of Japan Synthetic Rubber Co., Ltd.
(EP02P, EP07P, EP57P) and the like.

The acid modification of these elastomers can be carried out in the same manner as the above-mentioned acid modification of the polyolefin resin.
In the present invention, an unmodified polyolefin resin and an elastomer may be kneaded and simultaneously subjected to an acid modification treatment. In the present invention, the acid-modified polyolefin resin may further contain up to 2000 parts by weight of an unmodified polyolefin resin per 100 parts by weight of the resin. At this time, it is preferable to mix the mixture so that the amount of the unsaturated carboxylic acids grafted in the mixture falls within the above range. Examples of such an unmodified polyolefin resin include polypropylene and polyethylene, which are raw materials for the above-mentioned acid-modified polyolefin resin.

The adhesive layer is made of an acid-modified polyolefin resin and EV
OH is melt-mixed. As the physical properties of the EVOH resin, those having the same physical properties as those of the central layer described above are preferable. EVOH resin is contained in the obtained resin composition.
It is melt-mixed so as to be 2 to 40% by weight, preferably 10 to 25% by weight. Outside these ranges, the effect of improving the adhesiveness and transparency is reduced.

Furthermore, the resin composition of the present invention may contain a heat-resistant stabilizer, a weather-resistant stabilizer, a lubricant, an antistatic agent, a nucleating agent, a filler, a pigment, a dye, a flame retardant, and an anti-blocking agent, which are generally used. And the like may be contained in an amount of about 0.0005 to 30% by weight. EVOH for acid-modified polyolefin resin
When the resins are mixed, a general method may be used, and there is no particular limitation. In order to improve the transparency, the specific energy to the resin is 0.3 kW · hr / kg or more, preferably 0.4 kW · hr / kg or more. It is desirable to melt-mix under the condition of ~ 2.0 kw · hr / kg. For example, an acid-modified polyolefin resin and an EVOH resin are mixed under the above conditions at 190 to 190.
Melt and mix at 350 ° C. with a screw extruder, Banbury mixer, mixing roll, or the like.

When the acid-modified polyolefin resin and the EVOH resin are melt-mixed under such conditions, the EVOH resin is micro-sized and uniformly dispersed in the acid-modified polyolefin resin, so that the transparency is remarkably improved. Here, the specific energy refers to (1
Kg) means the energy given to the resin from the kneading equipment for the effect of kneading. The larger the value, the higher the effect of kneading.

For example, in the case of an extruder, it is approximately represented by the power consumption of a screw driving motor required to extrude 1 kg of resin. In the case of a roll-type kneader such as a Banbury mixer, the power is approximately represented by the power consumption of a roll driving motor necessary for processing 1 kg of resin. Specifically, an ammeter, a voltmeter, etc. were attached to the motor of the extruder, and the power consumption of the motor was obtained from this, multiplied by the power factor of the motor (normally about 0.85), and 1 kg
To obtain a kneading force (kw · hr / kg) applied to the resin.

In practice, acid-modified polyolefin resin and E
VOH is melt-mixed at 200 to 350 ° C. using a screw extruder, a Banbury mixer, a mixing roll, or the like. The wrapping film of the present invention is obtained by co-extrusion of an adhesive resin (adhesive layer) obtained by melt-mixing the polyolefin resin (inner / outer layer), EVOH resin (center layer), acid-modified polyolefin resin and EVOH. Layer structure of five seed layers, for example [polypropylene resin / adhesive resin / EV
OH resin / adhesive resin / polypropylene resin].

As the co-extrusion molding, a T-die molding method or a water-cooled inflation molding method is preferably employed. That is, by rapidly cooling the melt-extruded resin by the above-mentioned molding method, a film having more excellent transparency can be obtained as compared with an air-cooled inflation molding method which is usually used frequently. The unstretched multilayer film obtained by the co-extrusion molding is then uniaxially stretched in the film take-up direction (longitudinal direction) to a stretching ratio of 2 to 6 times, preferably 2.5 to 4 times. The stretched magnification is less than 2 times is insufficient cutting of the film, also decreased is large and extensible than 6 times, Ru can stretch unevenness rupture or film. The stretching treatment is performed by heating the unstretched film as it is or by slitting the film to a predetermined width, and stretching the film in the take-off direction, that is, the longitudinal direction by changing the peripheral speed of a stretching roll. The preheating temperature in the stretching treatment is usually at most [the melting point of the polyolefin resin-20 ° C] or lower, preferably in the range of 40 to 120 ° C.

The heat setting temperature after stretching is preferably higher than the preheating temperature, and is preferably as high as possible for preventing wrinkles and improving the lateral strength of the film. Melting point -20 ° C] or lower, preferably in the range of 80 to 150 ° C. If the preheating and heat setting temperature is higher than [melting point of polyolefin resin-20 ° C], the film is melt-adhered to the stretching roll, and if the preheating temperature is lower than 40 ° C,
Unsatisfactory preheating of the EVOH resin makes stretching difficult and film breakage occurs, which is not desirable.

[0028] As the thickness of the wrap film of the present invention is
2 ~50μm, good Mashiku is in the range of 5 to 20 [mu] m,
The thickness of the central layer is 10% of the total thickness of the film.
９０90%. If the thickness of the film is larger than 50 μm, the tear strength when cutting the film becomes too large. If the thickness of the central layer is less than 10% of the total thickness, the original transparency and the like of the EVOH resin cannot be maintained,
In addition, since the physical properties of the uniaxially stretched polyolefin film become dominant, the film tends to tear in the stretching direction. The thickness of the central layer is preferably at least 15% of the total thickness. Conversely, if it is larger than 90%, the thickness of the polyolefin layer becomes thin, and it becomes difficult to uniformly cover the central layer by coextrusion molding. The thickness of the central layer is preferably not more than 80% of the total thickness.

The film for wrap of the present invention is used for various wraps such as food packaging. Of improving the adhesion of the wrap film by imparting self-adhesive in a more suitable manner to the outer layer and the inner layer constituting the both surface layers
Can be made .

[0030]

EXAMPLES Hereinafter, specific embodiments of the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples unless it exceeds the gist thereof.
The measurement in the examples was performed by the following method. (1) Moisture permeability Measured at 40 ° C. and 90% RH according to JIS Z0208.

(2) Transparency The transparency was measured using a transparency measuring device manufactured by Murakami Color Research Laboratory. Although three types of measured values, MAX value, MIN value, and AVE value, can be obtained, they are indicated by the MAX value most corresponding to visual perception.

(3) Heat-resistant temperature A strip-shaped film having a width of 30 mm and a length of 14 cm, a paper is placed on the top and bottom 25 mm of a sample piece, and a weight of 10 g is lowered. The maximum ambient temperature that could not be cut in one hour was measured at 10 ° C intervals.

(4) Heat shrinkage ratio The film is made into a sample having a diameter of 10 mm by a punching jig.
This is immersed in an aluminum pan containing silicone oil, and the aluminum pan is placed on a hot plate at 140 ° C. Although the temperature of the hot plate temporarily drops because heat is taken by the aluminum pan, a sample is taken out 45 seconds after the temperature reaches 140 ° C., and the size change is measured.

(5) Cutability The film was wound around a core tube, housed in a wrap film case, subjected to a cutting test with a saw blade, and evaluated on a 4-level scale (good, normal, slightly poor, poor). As a standard for evaluation, the cut level of a commercially available wrap film was evaluated as normal.

(6) Adhesive Strength The adhesive strength between the adhesive layer ( adhesive resin) and the center layer (EVOH), which is a problem in the film of the present invention, was evaluated.

Example 1 Using a 450 mm wide three-layer, five-layer coextrusion T-die molding machine, Table 1 was used.
Are extruded simultaneously from three extruders at a die temperature of 280 ° C., a chill roll temperature of 25 ° C., and a take-up speed of 10 m / m.
And a three-layer five-layer film (thickness) consisting of an outer layer (polypropylene) / adhesive layer ( adhesive resin) / center layer (EVOH resin) / adhesive layer ( adhesive resin) / inner layer (polypropylene) 30 μm, layer ratio 1: 1: 1: 1:
1) was molded. Then, the film is stretched in a longitudinal direction at a preheating temperature of 60 ° C. and a heat setting temperature of 110 ° C. by roll stretching.
The film was stretched 3.3 times. The moisture permeability, transparency, heat resistance temperature, heat shrinkage and cutability of the obtained film were evaluated by the above methods. Table 5 shows the results.

[0037]

[Table 1]

Polypropylene: propylene-ethylene random copolymer, manufactured by Mitsubishi Kasei Co., Ltd., Mitsubishi Polypro 65
00J, MFR; 9 g / 10 min (230 ° C.), density;
0.9 g / cm ³ modified polypropylene: 100 parts of Mitsubishi Polypropylene 6500J
Parts by weight, 1 part by weight of maleic anhydride, 2,5-dimethyl-
0.15 parts by weight of 2,5-di (t-butylperoxy) hexyne-3 was melt-kneaded at 210 ° C. in a 50 mmφ extruder to form a pellet, thereby obtaining a modified polypropylene. The grafted amount of maleic anhydride of this modified polypropylene was 0.35% by weight. EVOH resin: (ethylene-vinyl alcohol copolymer, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name: Soarnol, ET3803, ethylene content: 38 mol%, M
FR; 4.0 g / 10 minutes (230 ° C.)

Example 2 In Example 1, the ratio of each layer of the multilayer film was 3: 1: 2:
The same procedure was performed except that the ratio was 1: 3. Table 5 shows the results.

Example 3 The procedure of Example 1 was repeated, except that the raw fabric was formed by water-cooled inflation. Table 5 shows the results. The raw material molding conditions were as follows: die diameter 75 mm
φ, die temperature 250 ° C, blow-up ratio 1.8, take-up speed 10m / min, folding width 210mm, thickness 3
A 0 μm film was formed.

Example 4 The multilayer film obtained in Example 1 was pulverized and then pelletized with a single screw extruder under the conditions of a specific energy of 0.5 kw · hr / kg to obtain a recycled material. The procedure was performed in the same manner as in Example 1 except that this recycled material was used for the adhesive layer. Table 5 shows the results. This shows that the performance is excellent even if the loss is recovered and recycled.

Example 5 The procedure of Example 1 was repeated except that the raw materials used for the inner and outer layers and the adhesive layer were the raw materials shown in Table 2. Table 5 shows the results.

[0043]

[Table 2]

Linear low-density polyethylene: Mitsubishi Kasei Corporation
Manufactured by Mitsubishi Polyethylene UF340, MFR; 2.0 g / 10
Min (190 ° C.) density; 0.922 g / cm ³ modified low-density polyethylene: 1 from Mitsubishi Polyethylene UF340
00 parts by weight, 1 part by weight of maleic anhydride, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-
3 was used in an amount of 190 wt.
The mixture was melt-kneaded at a temperature of 0 ° C and pelletized to obtain a modified low-density polyethylene. The grafted amount of maleic anhydride of this modified low-density polyethylene was 0.35% by weight.

Example 6 The procedure of Example 1 was repeated except that the modified resin shown in Table 3 was used as a raw material for the adhesive layer. Table 5 shows the results.

[0046]

[Table 3]

Modified polypropylene: Mitsubishi Polypro 650
80 parts by weight of 0J, trade name; Tuffmer A4085 (manufactured by Mitsui Petrochemical Industries, Ltd.) MFR: 3.6 g / 10 min (1
90 ° C) density; 20 parts by weight of 0.88 g / cm ³ , 1 part by weight of maleic anhydride, and 0.15 part by weight of 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3 The resulting mixture was melt-kneaded at 210 ° C. using a 50 mmφ extruder and pelletized to obtain a modified polypropylene. The grafted amount of maleic anhydride of this modified polypropylene was 0.3
It was 5% by weight.

Example 7 The procedure of Example 1 was repeated, except that the modified resin shown in Table 4 was used as a raw material for the adhesive layer. Table 5 shows the results.

[0049]

[Table 4]

Modified polypropylene: Mitsubishi Polypro 650
0J 100 parts by weight, maleic anhydride 1 part by weight, 2,
0.15 parts by weight of 5-dimethyl-2,5-di (t-butylperoxy) hexine-3 was melt-kneaded at 210 ° C. in a 50 mmφ extruder and pelletized to obtain a modified polypropylene. The grafted amount of maleic anhydride of this modified polypropylene was 0.35% by weight.

Comparative Examples 1 to 4 The same procedures as in Example 1 were carried out except that the film thickness, the film layer ratio and the stretching ratio were as shown in Table 5. Table 5 shows the results.

Example 8 In Example 4, the multilayer film was pulverized to obtain a recycled material. A laminated film was produced in the same manner as in Example 1 except that the recycled material was used as an adhesive layer and the specific energy during co-extrusion was set to 0.2 kw · hr / kg. Table 5 shows the results.

[0053]

[Table 5]

[0054]

The wrapping film of the present invention is excellent in cuttability, transparency, interlayer adhesion, heat resistance, barrier properties, non-heat shrinkage, food safety and environmental suitability. Further, in the present invention, the use of an EVOH resin is excellent in productivity as described below.

Trim loss caused by the necessity of slitting and removing thick portions at both ends of the film due to the process of longitudinal uniaxial stretching, and loss of defective products caused by deviation from the standard such as thickness. Whether it can be collected and recycled has a great influence on productivity, and has a great effect on costs.
That is, it has been said that it is extremely difficult to carry out recycling of a multilayer transparent film, particularly because the transparency is a problem. However, according to the present invention, a film having a good performance such as transparency can be obtained by collecting and utilizing a trim loss composed of a mixture of a polyolefin, an EVOH resin, and an acid-modified polyolefin.

Although it is normally necessary to separately set a recovery layer using a recycled material, according to the present invention, by using a recycled material between the inner and outer layers and the central layer, the adhesive layer also serves as the recovery layer. Will be. This has the effect of simplifying the layer configuration and reducing the number of extruders required for coextrusion. Further, as a waste treatment after use, the plastic film is excellent in environmental suitability because it does not generate harmful gases such as NOx and hydrogen chloride which are problematic as gases generated during combustion.

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-3-262640 (JP, A) JP-A 1-275041 (JP, A) JP-A-59-215864 (JP, A) JP-A-56- 67254 (JP, A) JP-A-5-147177 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 1/00-35/00

Claims (4)

(57) [Claims] 1. A layer made of a polyolefin resin via an adhesive layer formed by melting and mixing an acid-modified polyolefin resin and an ethylene-vinyl alcohol copolymer resin on both sides of a layer made of an ethylene-vinyl alcohol copolymer resin. And stretched in the longitudinal direction at a stretch ratio of 2 to 6 times,
Body thickness is 2-50 μm, ethylene-vinyl alcohol
The thickness of the layer made of the copolymer resin is 10 to 90% of the entire thickness.
A film for wrap , characterized in that: 2. The adhesive layer according to claim 1, wherein the adhesive layer comprises 2 to 40% by weight of ethylene-
The wrapping film according to claim 1, comprising a vinyl alcohol copolymer resin. 3. The wrapping film according to claim 1, wherein the acid-modified polyolefin resin contains an acid-modified polyolefin elastomer. 4. An acid-modified polyolefin resin in an adhesive layer.
Blending of fat and ethylene-vinyl alcohol copolymer resin
If the specific energy is 0.3 kWhr / kg or more
4. A method as claimed in claim 1, wherein:
A wrapping film according to item 1.