JPH0717001A - Composite film and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain composite film, with which an article can be wrapped at high speed by a method wherein covering layer made of resin composition containing olefin-based polymer and copolymer consisting of olefin-based polymer unit and polyorganisiloxane unit is laminated on base material film layer. CONSTITUTION:Covering layer made of resin composition containing one olefin- based polymer A selected from the group consisting of propylene-ethylene copolymer, propylene-butene-1 copolymer and propylene-ethylene-butene-1 copolymer and copolymer B consisting of olefin-based polymer unit and polyorganosiloxane unit is laminated on one side or both sides of base material film layer, which is made of polypropylene stretched in one direction by the draw ratio of 150% or more. The content of the copolymer B in the covering layer is set to be 0.1-10 pts.wt. to 100 pts.wt. of the olefin-based polymer A. Further, the content of the copolymer B in the covering layer is set to be 0.1-5 pts.wt. of polyorganosiloxane to 100 pts.wt. of the olefin-based polymer A.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a composite film suitable for overlapping packaging and a method for producing the same.

[0002]

2. Description of the Related Art Various films, particularly polypropylene film and polyethylene terephthalate film, which are excellent in properties such as transparency and rigidity, are used as packaging materials. Furthermore, in addition to gas barrier properties against oxygen gas and water vapor, a film coated with a vinylidene chloride copolymer that has heat sealability is used as a film for overlapping packaging of various products such as foods, cigarettes and cassette tapes. Has been done.

On the other hand, a stretched film such as a biaxially stretched polypropylene film has poor heat sealability. Therefore, in the base film layer such as polypropylene film,
A laminated film obtained by laminating and stretching an olefin polymer layer having a heat-sealing property is also under study. But,
The laminated film in which the olefin polymer layer is laminated has inferior mechanical properties to an automatic wrapping machine for overlapping in a high-speed packaging application, for example, at a high speed of 250 pieces / minute or more. That is, in the automatic wrapping machine for overlapping, when the laminated film is used, heat and pressure act simultaneously, so that the slipperiness with respect to the metal guide plate and the releasability are significantly reduced. Therefore, the overwrapping cannot be performed at high speed, and the packaging workability is deteriorated.

In order to improve the slipperiness of the film, an anti-blocking agent consisting of inorganic fine powder such as silica, alumina, synthetic zeolite or organic fine powder such as polyethylene; adding mineral or petroleum wax to the olefin polymer. (For example, Japanese Patent Laid-Open No. 3-7
1830 publication).

However, even if such an additive is added,
In the automatic wrapping machine for overlapping, in a bonding step by thermocompression in which heat and pressure simultaneously act,
The releasability from the metal guide plate is poor. Therefore, it cannot be packaged at a speed of 250 pieces / minute or more.

Further, in order to improve the releasability of the film,
A method of adding a release agent such as silicone oil or polydimethylsiloxane gum is also known. However, since these release agents are electrically insulative, the film is charged during the overlapping, and high-speed packaging cannot be performed. More specifically, since the film is charged with static electricity during packaging, it electrostatically adheres to a metal guide plate or the like, the film does not run smoothly, and there is a problem that the film is jammed in the automatic wrapping packaging machine. Furthermore, since the heat-sealing temperature of the olefin polymer shifts to the high temperature side by the addition of the release agent, it becomes impossible to heat seal at a low temperature.

Further, it may be considered to add the antiblocking agent, the releasing agent and the antistatic agent to the olefin polymer. However, even in this case, it is difficult to perform high-speed packaging in an automatic packaging machine in which heat and pressure simultaneously act.

[0008] Therefore, it is an object of the present invention to provide a composite film capable of packaging articles at high speed.

Another object of the present invention is to provide a composite film which is excellent in slipperiness, releasability and antistatic property and which can package an article at a high speed by an automatic wrapping machine for overlapping.

Still another object of the present invention is to provide a method for producing a composite film having the above-mentioned excellent properties.

[0011]

In order to achieve the above-mentioned object, the present inventor has
As a result of earnest study, on at least one surface of the substrate film layer, an olefin polymer, and a layer containing a resin composition containing a copolymer composed of an olefin polymer unit and a polyorganosiloxane unit, is laminated, The present inventors have found that not only high slipperiness and releasability but also a reduction in antistatic property is suppressed and a composite film excellent in high-speed packaging suitability is obtained, and the present invention has been completed.

That is, according to the present invention, (1) a composite film in which a coating layer made of a resin composition containing (2) the following (A) and (B) is laminated on at least one surface of a base film layer: I will provide a.

(A) Olefin-based polymer (B) A copolymer composed of an olefin-based polymer unit and a polyorganosiloxane unit.

The present invention also provides (1) a method for producing a composite film, in which (2) a coating layer made of a resin composition containing the following (A) and (B) is laminated on at least one surface of the base film layer. I will provide a.

(A) Olefin-based polymer (B) A copolymer composed of an olefin-based polymer unit and a polyorganosiloxane unit.

(1) As the resin constituting the base film layer, for example, polyethylene, ethylene-ethyl acrylate copolymer, ionomer, polypropylene, propylene-ethylene copolymer, poly-4-methylpentene-
1, etc. Olefin-based resins; polyvinyl alcohol, ethylene-vinyl alcohol copolymers and other vinyl alcohol-based resins; polyvinyl chloride; vinylidene chloride-vinyl chloride copolymers, vinylidene chloride-acrylonitrile copolymers, and other vinylidene chloride resins Styrene-based resins such as polystyrene, styrene-acrylonitrile copolymer, styrene-acrylonitrile-butadiene copolymer;
Polyester such as polyethylene terephthalate and polybutylene terephthalate; nylon 6, nylon 11,
Nylon 12, Nylon 66, Nylon 610, Nylon 612, Nylon 6/66, Nylon 66/610,
Nylon or polyamide such as nylon 6/11; polyacrylonitrile; polycarbonate; polyimide; polyphenylene oxide; polysulfone; polyparaxylene; polyamideimide; polyesterimide.

(1) The base film layer is preferably composed of an olefin resin (especially propylene resin) and a polyester (especially polyethylene terephthalate). The preferred (1) substrate film layer is composed of a propylene-based resin which is excellent in transparency, rigidity and packaging suitability.

The propylene resin is preferably a crystalline propylene resin. The propylene-based resin may be a copolymer containing propylene as a constituent component, for example, a copolymer with ethylene, butene-1,1,3-methylpentene and other α-olefins, but a propylene homopolymer. Is preferred.

The isotactic index (II) of the propylene resin is 90% or more, preferably 95%.
Or more, More preferably, it is 96% or more. A propylene-based resin film having such an isotactic index (II) is suitable for automatic packaging because it runs straight without curling during film running.

The intrinsic viscosity [η] of propylene resin
Is usually 0.8 to 4 dl / g, preferably 1 to 2.5
It is about dl / g.

(1) The base film layer may be a monolayer film or a laminated film in which two or more kinds of polymer layers are laminated. (1) The thickness of the substrate film layer is not particularly limited, and is, for example, 1 to 250 μm, preferably 5 to 100 μm.

Further, (1) the base film layer, as long as the high-speed wrapping property is not impaired, various additives, for example, stabilizers such as antioxidants, ultraviolet absorbers and heat stabilizers; polyoxyethylene alkyl. Amine, quaternary ammonium salt, cationic type such as hydantoin derivative, sulfuric acid derivative, alkylsulfonate, anion type such as phosphoric acid derivative, polyhydric alcohol, ester of polyhydric alcohol such as glycerin and fatty acid, fatty acid ester Antistatic agents such as adducts with alkylene oxides such as ethylene oxide, nonionic compounds such as polyoxyethylene alkylphenol, amphoteric antistatic agents such as alkylbetaine; crystal nucleus growth agents; styrene resins, terpene resins, petroleum resins, Coumaron resins such as dicyclopentadiene resin and coumaron indene resin Phenol resins, hydrocarbon polymers such as rosin and its derivatives and their hydrogenated resins; plasticizers; fillers; stearic acid amide, oleic acid amide,
Acid amides such as erucic acid amides and alkylenebisstearic acid amides, higher fatty acids and their salts, higher fatty acid esters, natural waxes such as minerals and plants, synthetic waxes such as polyethylene; fine powders such as finely divided silica It may contain dyes and pigments.

In particular, (1) the base film layer contains the above-mentioned hydrocarbon polymer such as hydrogenated terpene resin, hydrogenated petroleum resin, dicyclopentadiene resin, etc. in order to strengthen the rigidity of the film. Is preferred. The content of the hydrocarbon polymer is, for example, 1 to 30% by weight, preferably 5 to 15%.
It is about% by weight.

The (1) substrate film layer containing an antistatic agent together with the above hydrocarbon polymer is useful for preventing electrostatic adhesion of the film to the packaging machine during the packaging operation. High-speed packaging suitability is further improved. The content of the antistatic agent is, for example, 0.01 to 5 parts by weight, preferably 0.1 to 2.5 parts by weight. Further, (1) the base film layer may contain wax in an amount of, for example, 0.01 to 5 parts by weight, preferably 0.1 to 2.5 parts by weight.

(1) A resin containing an olefin polymer (A) and a copolymer (B) composed of an olefin polymer unit and a polyorganosiloxane unit on one or both sides of the base film layer. Composed of composition (2)
The coating layers are laminated.

(2) The olefin polymer (A) contained in the coating layer includes, for example, olefin homopolymers such as ethylene, propylene, butene-1,3-methylpentene-1,4-methylpentene, and the like. Copolymers containing these olefins as constitutional units are included.

The preferred olefin polymer (A) is
Polymers with heat sealing properties, such as propylene
Ethylene copolymer, propylene-butene-1 copolymer,
Propylene-ethylene-butene-1 copolymer, ethylene-butene-1 copolymer, ethylene-3-methylpentene-1 copolymer, propylene-ethylene-3-methylpentene-1 copolymer, ethylene-4- Methyl pentene-1
Examples thereof include an olefin-based copolymer such as a copolymer, a propylene-ethylene-4-methylpentene-1 copolymer, and an ethylene-butene-1-3-methylpentene-1 copolymer. The olefin-based copolymer may be a random copolymer, a block copolymer or the like, and a random copolymer is usually used.

Particularly preferred olefin polymer (A)
Include propylene-ethylene copolymer, propylene-butene-1 copolymer, propylene-ethylene-butene-1.
Propylene-based copolymers such as copolymers are included. Of these, a propylene-ethylene-butene-1 copolymer is preferable.

In these propylene-based copolymers,
The propylene content is, for example, about 68 to 99% by weight, preferably about 70 to 96.5% by weight.

In the propylene-ethylene-butene-1 copolymer, the ethylene content is, for example, 0.3 to 8% by weight, preferably 0.5 to 5.0% by weight, and the butene-1 content is 1 to 30% by weight. %, Preferably about 3 to 25% by weight.

The olefin polymer (A) has a heat-sealing property, particularly a low-temperature heat-sealing property, in the heat-pressure bonding step required for high-speed overlapping packaging.
However, as described above, when the coating layer (2) is composed of the olefin polymer (A) alone, the sliding property with respect to the metal guide plate is not good in the high-speed overlapping packaging machine in which heat and pressure act.

On the other hand, when the (2) coating layer made of the resin composition containing the olefin polymer (A) and the copolymer (B) is formed, in the hot pressure bonding step of the high speed overlapping packaging machine, It is possible to obtain a composite film having high antistatic properties as well as slipperiness and releasability with respect to a metal guide plate and the like. Two such composite films are
The article can be smoothly wrapped and wrapped at a high speed of 50 pieces / minute or more.

The copolymer (B) may be a block copolymer, but is preferably a graft copolymer in which a polyorganosiloxane unit is graft-polymerized with an olefin polymer unit.

The olefin-based polymer unit constituting the copolymer (B) includes polymers containing various olefins, for example, olefins such as ethylene, propylene, butene-1,3-methylpentene-1,4-methylpentene. And homopolymers thereof; copolymers containing these olefins; ethylene- (meth) acrylic acid ester copolymers such as ethylene-ethyl acrylate copolymer and ethylene-methyl methacrylate copolymer. Preferred olefin-based polymer units include, for example, polyethylene and ethylene- (meth) acrylic acid ester copolymers.

The type of the polyorganosiloxane unit is not particularly limited, and examples thereof include polyalkylsiloxanes such as polydimethylsiloxane, polyarylsiloxanes such as polydiphenylsiloxane, and polyalkylarylsiloxanes.

The molecular weight of the polyorganosiloxane unit is not particularly limited, but is, for example, 100 to 100,000, preferably 500 to 75,000, and preferably 1,000 to 5.
It is about 0000.

The silicone content in the copolymer (B) is usually about 25 to 75% by weight, preferably about 40 to 60% by weight.

As an example of such a copolymer (B),
Examples include those commercially available from Nippon Unicar Co., Ltd. under the name of thermoplastic silicone elastomer.

(2) The content of the copolymer (B) in the coating layer is appropriately selected within a range capable of enhancing the wrapping property of the film, depending on the content of the polyorganosiloxane of the copolymer (B) and the like. You can choose. The content of the copolymer (B) is
With respect to 100 parts by weight of the olefin polymer (A) (unless otherwise specified, (2) when the content in the coating layer is expressed as parts by weight, it means that with respect to 100 parts by weight of the olefin polymer-100 (A)), For example, it is 0.1 to 10 parts by weight, preferably 0.2 to 5 parts by weight, and more preferably 0.5 to 2.5 parts by weight. When the content of the copolymer (B) is less than 0.1 parts by weight, the slipperiness and releasability of the film are deteriorated, and when it exceeds 10 parts by weight, the heat-sealable temperature shifts to a high temperature side, resulting in poor sealing. Is likely to occur.

The content of the copolymer (B) in the coating layer (2) is, for example, olefin polymer (A).
The amount of polyorganosiloxane is 0.1 to 5 parts by weight, preferably 0.15 to 3 parts by weight, and more preferably 0.2 to 1 part by weight, based on 100 parts by weight.

(2) The coating layer may contain various additives which can be added to (1) the base film layer. Especially 10
In order to improve the slipperiness under a low temperature of 0 ° C. or less, it is useful to add an antiblocking agent, wax and the like. As the anti-blocking agent, fine powder such as fine powder silica, particularly inorganic fine powder having an average particle size of about 1 to 5 μm can be used, and as wax, acid amide such as stearic acid amide and erucic acid amide can be used. The use of the antiblocking agent and / or wax, in combination with the action of the copolymer (B), enables the smoothing of the overlapping packaging at a higher speed. The antiblocking agent and the wax are added in an amount of, for example, 0.05 to 5 parts by weight, preferably 0.1 to 3 parts by weight based on 100 parts by weight of the olefin polymer (A).
It is about part by weight.

(2) The thickness of the coating layer can be selected within a range that does not impair the characteristics of the film, and is, for example, 0.1 to 50 μm, preferably 0.5 to 25 μm, more preferably 1 to 5 μm.
It is about m.

The composite film composed of (1) the base film layer and (2) the coating layer may be unstretched,
It is preferably stretched. The stretched film may be a uniaxially stretched film, but is preferably a biaxially stretched film, particularly a film containing a biaxially stretched polypropylene film layer. Moreover, the stretched film may be heat-treated, if necessary.

The surface of the composite film may be subjected to a conventional surface treatment, such as corona discharge treatment or high frequency treatment, if necessary.

The composite film of the present invention is obtained by laminating (1) a base film layer and (2) a coating layer made of a resin composition containing an olefin polymer (A) and a copolymer (B). be able to. More specifically, the composite film can be obtained by a dry lamination method or a coextrusion molding method. The preferred method is the coextrusion method.

In the dry laminating method, the surface of at least one of (1) the base film layer and (2) the coating layer comprising the resin composition containing the olefin polymer (A) and the copolymer (B) is covered. For example, it can be carried out by treating with an anchor coating agent such as a titanium-based anchor coating agent, a polyethyleneimine-based anchor coating agent, a urethane-based anchor coating agent or the like and stacking. In the dry lamination method, (1) base film layer and (2)
A stretched film can be used as the coating layer.

In the coextrusion molding method, (1)
It can be obtained by co-extruding the resin composition forming the base film layer and the resin composition forming the coating layer (2). The extruded composite film is preferably subjected to a stretching step. Coextrusion molding can be performed according to a conventional method. For example, T-die,
(1) The resin composition constituting the base film layer and (2) the resin composition constituting the coating layer are individually charged into an extrusion molding machine equipped with a ring die and the like, and the inside of the die is extruded by the extruder. Melt extrude. In the flow path in the die, (1) the resin composition of the base film layer and (2) the resin composition of the coating layer are combined and laminated, and melt-extruded from the die and cooled to obtain a composite film.

Stretching of the composite film can be carried out in the T-die method after cooling the composite film extruded from the die, and in the inflation method, it can be carried out together with melt extrusion from the die.

Examples of the stretching method include conventional stretching methods such as roll stretching, rolling stretching, belt stretching, tenter stretching, tube stretching, and stretching methods combining these. The draw ratio can be appropriately set according to the desired characteristics of the film. The preferred draw ratio is 1.5 times or more in at least one direction, and more preferably about 2 to 10 times.

In the composite film of the present invention, (1) various coating layers or laminating layers may be formed depending on the type and application of the base film layer. For example, in order to enhance the oxygen gas barrier property, the composite film may be coated with a vinyl alcohol-based polymer, and in order to enhance the barrier property against carbon dioxide gas and water vapor including oxygen gas, a vinylidene chloride-based polymer may be coated. Good. Further, a slipping layer or the like may be formed on the composite film.

Preferred embodiments of the present invention are as follows.

(A) (1) A propylene-based copolymer (for example, propylene-ethylene copolymer) having heat sealability as the olefin-based polymer (A) is provided on at least one surface of the polypropylene film layer which is the base film layer. From a resin composition containing a copolymer, at least one propylene-based copolymer selected from the group consisting of a propylene-butene-1 copolymer and a propylene-ethylene-butene-1 copolymer) and the copolymer (B) (2) A composite film in which the coating layers are laminated and biaxially stretched.

(B) A composite film in which the polypropylene film layer contains a hydrocarbon polymer and an antistatic agent.

(C) The propylene-based copolymer of the olefin polymer (A) has an ethylene content of 0.5 to 5% by weight,
A composite film which is a propylene-ethylene-butene-1 copolymer having a butene-1 content of 3 to 25% by weight.

(D) (2) A composite film in which a coating layer contains an antiblocking agent, preferably a fine powdery antiblocking agent and a wax.

(E) The copolymer (B) is a polyethylene unit or an ethylene-based olefin polymer unit.
A composite film which is a graft copolymer obtained by graft-polymerizing a polyorganosiloxane on a (meth) acrylic acid ester copolymer.

The present specification also discloses an overlapping method in which the composite film is used to package articles at a speed of 250 pieces / minute or more.

[0058]

In the composite film of the present invention, (2) the coating layer comprises the olefin polymer (A) and the copolymer (B).
Since it is a layer composed of a resin composition containing, the article can be packaged at high speed by the composite film. Further, the composite film has high slipperiness and releasability, and further, deterioration of the antistatic property is suppressed. Therefore, articles can be packaged at high speed by the automatic packaging machine for overlapping.

According to the manufacturing method of the present invention, a composite film having the above-mentioned excellent properties can be obtained.

[0060]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited thereto.

Example 1 The following resin compositions were used as the raw material (X) for the base film layer (1) and the raw material (Y) for the coating layer (2).

(1) Raw material (X) for the base film layer: isotactic polypropylene (melt index:
2.0 g / 10 minutes, melting point 160 ° C.) 90 parts by weight, petroleum resin (Arakawa Chemical Industry Co., Ltd., trade name Alcon P-12)
5) 10 parts by weight, a mixture of an alkylamine / ethylene oxide adduct and stearic acid monoglyceride 0.5
A kneaded product of 1 part by weight and 0.1 part by weight of stearic acid amide.

(2) Raw material (Y) for coating layer: As olefin polymer (A), propylene-ethylene-butene-1 random copolymer (ethylene content 3.9% by weight, butene-1 content 4.4%). %, Melt index 9.0
g / 10 minutes) 100 parts by weight, as a copolymer (B), a thermoplastic silicone elastomer in which polyethylene is graft-polymerized (manufactured by Nippon Unicar Co., Ltd., trade name SILGRAFT-210, silicone content 50% by weight). A kneaded product of 1.4 parts by weight, 0.4 parts by weight of finely divided silica having an average particle size of 4 μm, and 0.1 part by weight of stearic acid amide. The raw materials (X) and (Y) are mixed with T
Each is supplied to an extruder equipped with a die,
Co-extrusion molding at a temperature of 230 ° C, layer structure Y / X / Y
A sheet having a thickness of 1.4 mm was prepared from the two types and three layers described above. The obtained sheet was stretched 6 times in the longitudinal direction with a roll of 100 to 120 ° C., then stretched 10 times in the width direction at a temperature of 160 ° C., and then heat-treated at 160 ° C. for 10 seconds to form a corona on one side of the film. Discharge treatment was carried out to produce a composite film of two types and three layers. The thickness of the obtained composite film was 23 μm (the thickness of the X layer was 20 μm, the thickness of each Y layer was 1.5 μm).

Example 2 The raw material (Y) for the coating layer (2) of Example 1 was replaced with the following raw material (Y).
A 2-type, 3-layer composite film was produced in the same manner as in Example 1 except that 2) was used.

Raw material (Y2): As olefin polymer (A), propylene-ethylene copolymer (ethylene content 5.8% by weight, melt index 5.5 g / 1
0 minutes) 100 parts by weight, as a copolymer (B), a thermoplastic silicone elastomer obtained by graft-polymerizing a polyorganosiloxane on an ethylene-methylmethacrylate copolymer (manufactured by Nippon Unicar Co., Ltd., trade name SIGLRAFT).
-150, silicone content 50% by weight) 1.0 parts by weight,
A kneaded product of 0.3 part by weight of finely divided silica having an average particle size of 3 μm and 0.1 part by weight of stearic acid amide.

Example 3 The raw material (Y) for the coating layer (2) of Example 1 was replaced with the following raw material (Y).
A 2-type, 3-layer composite film was produced in the same manner as in Example 1 except that 3) was used.

Raw material (Y3): As olefin polymer (A), propylene-butene-1 copolymer (butene-1 content 23.2% by weight, melt index 5.0)
g / 10 minutes) 100 parts by weight, as a copolymer (B), a thermoplastic silicone elastomer in which polyethylene is graft-polymerized (manufactured by Nippon Unicar Co., Ltd., trade name SILGRAFT-210, silicone content 50% by weight). A kneaded product of 1.4 parts by weight, 0.4 parts by weight of finely divided silica having an average particle size of 4 μm, and 0.1 part by weight of stearic acid amide.

Comparative Example 1 A two-kind, three-layer composite film was prepared in the same manner as in Example 1 except that the thermoplastic silicone elastomer was omitted from the raw material (Y) for coating layer (2) of Example 1. .

Comparative Example 2 In the raw material (Y) for the coating layer (2) of Example 1, 0.4 part by weight of polydimethylsiloxane gum having a degree of polymerization of 4500 was used in place of 1.4 parts by weight of the thermoplastic silicone elastomer. A two-kind three-layer composite film was produced in the same manner as in Example 1 except that it was used.

Then, the high-speed overlapping packaging suitability, antistatic property, and heat sealability of the composite films obtained in Examples and Comparative Examples were evaluated as follows.

High-speed overlapping wrapping suitability: A carton containing 20 cigarettes is automatically wrapped by an automatic wrapping machine (manufactured by Tokyo Automatic Machinery Co., Ltd., W323 type).
Was used to automatically package each composite film. Packaging is 2
Packaging was carried out for 2 minutes at a packaging speed of 250 pieces / min under conditions of 0 ° C. and 55% RH, and the packaging suitability was evaluated according to the following criteria.

(1) Adhesion of the film to the metal guide plate Excellent: No adhesion No: Adhesion (2) The number of packages that can be packaged before the machine is stopped because the film is jammed in the packaging machine (3) End of packaging Sealing property of the sealed part of the subsequent package: Excellent: Not sealed: Not sealed Antistatic property: Measured with a static Honest meter manufactured by Shishido Electrostatic Co., Ltd. at 20 ° C and 55% RH did. Fix the sample film (37mm x 50mm), and
Charge potential V (m when a voltage of kV is applied for 20 seconds
V) and the time t (second) until the charging potential is reduced to half after the voltage application is stopped were measured and displayed in V / t = mV / second.

Heat-sealing property: Using a heat-gradient heat sealer (manufactured by Toyo Seiki Co., Ltd.), the corona discharge treated surface and the non-treated surface of the composite film were pressure 1 kg / cm ² , time 1
It was heat-pressed and heat-sealed in seconds. The heat-sealed portion was peeled off, and the peeling strength per 15 mm width was measured at a speed of 300 mm / min using Tensilon manufactured by Toyo Baldwin Co., Ltd.

The results are shown in the table.

[0075]

[Table 1] As is clear from the table, the composite films obtained in Examples 1 to 3 are excellent in packaging suitability, antistatic property and heat sealing property, and even if they are packaged at a high speed of 250 pieces / minute, no trouble occurs. No, I was able to wrap it smoothly.

On the other hand, the composite film obtained in Comparative Example 1 had poor slipperiness, and automatic packaging was stopped when 30 cigarettes were packaged. In addition, the composite film obtained in Comparative Example 2 had a significant decrease in antistatic property, the film adhered to the packaging machine due to the generation of static electricity and could not be packaged continuously, and the sealing property of the seal portion was not limited. Was also inferior.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor ▲ Yoshi ▼ Teruaki Tada 5-1 Anezaki Kaigan, Ichihara City, Chiba Sumitomo Chemical Co., Ltd.

Claims (6)

[Claims] 1. A composite film comprising (1) at least one surface of a base film layer, and (2) a coating layer made of a resin composition containing the following (A) and (B). (A) an olefin polymer, (B) a copolymer composed of an olefin polymer unit and a polyorganosiloxane unit. 2. (1) The base film layer is made of polypropylene, and the film has a thickness of 1.5 in at least one direction.
The composite film according to claim 1, which is stretched by a factor of 2 or more. 3. The olefin polymer (A) is at least one propylene selected from the group consisting of a propylene-ethylene copolymer, a propylene-butene-1 copolymer and a propylene-ethylene-butene-1 copolymer. The composite film according to claim 1, which is a system copolymer. 4. The composite film according to claim 1, wherein the content of the copolymer (B) in the coating layer (2) is 0.1 to 10 parts by weight with respect to 100 parts by weight of the olefin polymer (A). 5. The content of the copolymer (B) in the coating layer (2) is 0.1 to 5 parts by weight as a polyorganosiloxane with respect to 100 parts by weight of the olefin polymer (A). The composite film described. 6. A method for producing a composite film, comprising: (1) laminating a coating layer made of a resin composition containing (2) the following (A) and (B) on at least one surface of a base film layer. (A) an olefin polymer, (B) a copolymer composed of an olefin polymer unit and a polyorganosiloxane unit.