JPH06238830A - Composite film and production thereof - Google Patents

Abstract

PURPOSE:To pack an article at a high speed by an automatic packing machine for overlapping using a composite film excellent in slip properties, releasability, antistatic properties and printability. CONSTITUTION:A polymer layer containing an olefinic polymer having heat sealability and a copolymer of a vinyl monomer such as an acrylic monomer and a polyorganosiloxane type macromonomer is laminated to at least one surface of a base material film layer composed of polypropylene and the obtained laminate is stretched to obtain a composite film. As the olefinic polymer having heat sealability, an ethylenic copolymer such as an ethylene/ propylene copolymer or an ethylene/propylene/butene-1 copolymer is designated. As the above mentioned copolymer, a graft copolymer obtained by the graft polymerization of a macromonomer and the acrylic polymer of a backbone part in a comb form is designated. The content of the graft polymer in a coating layer is 0.1-10wt.%.

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 As a packaging material, various films, particularly polypropylene film and polyethylene terephthalate film, which are excellent in properties such as transparency and rigidity, are used. 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-based polymer layers are laminated has poor mechanical properties for an automatic wrapping machine for overlapping in applications where it is packaged at a high speed, for example, at a high speed of 300 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. Further, the residual heat generated by the side sealing of the package blocks the film package in the packaging process and prevents the package from being smoothly transferred to the next process. 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 300 pieces / minute or more.

Further, in order to improve the releasability of the film,
A method of adding a releasing agent such as silicone oil or polydimethylsiloxane gum is also known (Japanese Patent Publication No. 63-568).
64, JP-A-59-13350, JP-A-2-60745, and JP-A-3-205440).

However, since these release agents are electrically insulative, the film is charged during the overlapping and cannot be packaged at a high speed. More specifically, since the film is charged with static electricity at the time of 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 an automatic wrapping machine for overlapping. 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. In addition, since silicone oil and silicone gum have low surface tension, printing ink, printing ink and adhesive for laminating are repelled even when directly printing, printing or laminating on a film containing silicone oil or silicone gum. , Printing, marking and laminating are difficult.

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.

[0009]

SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to provide a composite film that can package articles at high speed.

Another object of the present invention is that it is excellent in slipperiness, releasability and antistatic property, that it can package an article at a high speed by an automatic wrapping machine, and is excellent in printability, printability and lamination suitability. To provide a composite film.

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

[0012]

In order to achieve the above-mentioned object, the present inventor has
As a result of diligent studies, on at least one surface of the substrate film layer, an olefin polymer and a copolymer of a vinyl monomer and an organosiloxane macromonomer (hereinafter simply referred to as a silicone macropolymer unless otherwise specified). When a polymer layer containing a (monomer copolymer) is laminated, not only slipperiness and releasability but also unexpectedly high antistatic property and printing ink adhesion are obtained, and a composite film excellent in high-speed packaging suitability is obtained. Therefore, the present invention has been completed.

That is, the present invention provides a composite film in which (1) a base film layer, and (2) a coating layer containing an olefin polymer and a silicone macromonomer copolymer are laminated on at least one surface thereof. To do.

The present invention also provides a method for producing a composite film, which comprises laminating (2) a polymer layer containing an olefin polymer and a silicone macromonomer copolymer on (1) a base film layer.

In the present specification, methacrylic monomers and acrylic monomers are collectively referred to as "(meth) acrylic monomers", and methacrylic polymers, acrylic polymers and their copolymers are referred to as "(meth) acrylic monomers". Collectively referred to as "(meth) acrylic polymer".

Examples of the polymer constituting the base film layer include olefins such as polyethylene, ethylene-ethyl acrylate copolymer, ionomer, polypropylene, ethylene-propylene copolymer and poly-4-methylpentene-1. -Based polymers; vinyl alcohol-based polymers such as polyvinyl alcohol and ethylene-vinyl alcohol copolymers; polyvinyl chloride; vinylidene chloride-vinyl chloride copolymers, vinylidene chloride-based polymers such as vinylidene chloride-acrylonitrile copolymers; polystyrene, styrene -Styrene polymers such as acrylonitrile copolymer and styrene-acrylonitrile-butadiene copolymer; polyesters such as polyethylene terephthalate and polybutylene terephthalate; nylon 6, nylon 11 Nylon or nylon such as nylon 12, nylon 66, nylon 610, nylon 612, nylon 6/66, nylon 66/610, nylon 6/11; polyacrylonitrile; polycarbonate; polyimide; polyphenylene oxide; polysulfone; polyparaxylene; polyamideimide Polyester imide and the like.

The base film layer is preferably composed of an olefin polymer (especially polypropylene polymer) and a polyester (especially polyethylene terephthalate). A preferred base film layer is composed of a polypropylene-based polymer which is excellent in transparency and packaging suitability.

The polypropylene-based polymer is preferably a crystalline polypropylene-based polymer. The propylene-based polymer may be a copolymer having propylene as a constituent component, for example, a copolymer with ethylene, butene, an α-olefin such as 1,3-methylpentene, but a propylene homopolymer is preferable. .

The isotactic index (II) of the propylene-based polymer is 90% or more, preferably 9
It is preferably 5% or more, and more preferably 96% polypropylene. A polypropylene-based polymer film having such an isotactic index (II) is suitable for automatic packaging because it runs straight without curling when the film runs.

The intrinsic viscosity [η] of the propylene-based polymer is usually 0.8 to 4 dl / g, preferably 1 to
It is about 2.5 dl / g.

The base film layer may be a monolayer film or a laminated film in which two or more polymer layers are laminated. The thickness of the base film layer is not particularly limited, and for example, the thickness is 1 to 250 μm, preferably 5 to 10
It is about 0 μm.

Further, the base film layer contains various additives such as an antioxidant, as long as the high speed wrapping property is not impaired.
Stabilizers such as UV absorbers and heat stabilizers; polyoxyethylene alkyl amines, quaternary ammonium salts, cations such as hydantoin derivatives, sulfuric acid derivatives, alkyl sulfonates, anions such as phosphoric acid derivatives, polyhydric alcohols , An ester of a polyhydric alcohol such as glycerin and a fatty acid, an adduct of a fatty acid ester and an alkylene oxide such as ethylene oxide, a nonionic agent such as polyoxyethylene alkylphenol, and an antistatic agent such as an amphoteric antistatic agent such as alkylbetaine; Crystal nucleus growing agent; styrenic resin, terpene resin, petroleum resin, dicyclopentadiene resin, coumarone resin such as coumarone indene resin, phenolic resin, hydrocarbon polymer such as rosin and its derivatives and hydrogenated resins thereof Plasticizer; filler; stearic acid Acid amides such as amides, oleic acid amides, erucic acid amides, and alkylenebisstearic acid amides, higher fatty acids and their salts, higher fatty acid esters, natural waxes such as minerals and plants, and synthetic waxes such as polyethylene; Fine powder such as powdered silica; dyes and pigments may be included.

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

The film containing an antistatic agent together with the hydrocarbon polymer is useful for preventing the film from electrostatically adhering to the packaging machine during the packaging operation, and is further suitable for high-speed packaging. improves. The content of the antistatic agent is
For example, 0.01 to 5% by weight, preferably 0.1 to 2.
It is about 5% by weight. Further, the base film layer contains wax, for example, 0.01 to 5% by weight, preferably 0.0
You may contain about 2-1.0 weight%.

A coating layer containing (a) an olefin polymer and (b) a silicone macromonomer copolymer is laminated on one side or both sides of the base film layer.

Examples of the olefin polymer (a) contained in the coating layer include ethylene, propylene, butene-
Homopolymers of olefins such as 1,3-methylpentene-1 and 4-methylpentene, and copolymers containing these olefins as constituent units are included.

A preferred olefin polymer is a polymer having heat sealability, particularly an ethylene copolymer containing ethylene as a constituent component. Examples of the ethylene-based copolymer include ethylene-propylene copolymer,
Ethylene-butene-1 copolymer, ethylene-propylene-butene-1 copolymer, ethylene-3-methylpentene-1 copolymer, ethylene-propylene-3-methylpentene-1 copolymer, ethylene-4- Methyl pentene-1
Examples thereof include ethylene-α-olefin copolymers such as copolymers, ethylene-propylene-4-methylpentene-1 copolymers and ethylene-butene-1-3-methylpentene-1 copolymers. The ethylene-based copolymer may be a random copolymer, a block copolymer or the like, and a random copolymer is usually used.

Particularly preferred ethylene copolymers are ethylene-propylene copolymer and ethylene-propylene-
Butene-1 copolymer and the like are included. Among them, ethylene-propylene-butene-1 copolymer is preferable.

In the ethylene-propylene-butene-1 copolymer, the ethylene content is, for example, 0.3 to 10% by weight, preferably 0.5 to 5.0% by weight, and the butene-1 content is 1 to 50% by weight. %, Preferably about 5 to 20% by weight.

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

On the other hand, the olefin polymer (a) is added to the silicone macromonomer copolymer (b).
When the coating layer is formed by adding the compound, it has a high antistatic property, printability, and printability in addition to slipperiness and releasability for metal guide plates in the heat and pressure bonding process of a high-speed overlapping packaging machine. A film is obtained. Such a composite film can smoothly overwrap and package articles at a high speed of 300 pieces / minute or more.

The silicone-based macromonomer copolymer (b) contained in the coating layer may be a random copolymer, a block copolymer or the like. It is preferable that the macromonomer is a graft copolymer obtained by graft polymerization. Such a graft copolymer is usually a comb-type graft polymer whose main part is mainly composed of a vinyl monomer polymer and whose branch part is mainly composed of polyorganosiloxane (Toagosei Kagaku Kogyo Co., Ltd. ), Cymac) are commercially available.

As the vinyl-based monomer, a radically polymerizable α, β-ethylenically unsaturated compound, for example, α,
β-ethylenically unsaturated carboxylic acid (for example, (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid, etc.); (meth) acrylic acid alkyl ester (for example,
Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth)
Acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth)
Acrylate, cyclohexyl (meth) acrylate,
Phenyl (meth) acrylate, benzyl (meth) acrylate, etc .; (meth) acrylic monomer having a hydroxyl group (for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, etc.); glycidyl group Having (meth) acrylate (for example, glycidyl (meth) acrylate); aromatic vinyl compound (for example, styrene, α-methylstyrene, vinyltoluene, etc.); vinyl acetate, vinyl caproate, vinyl propionate, and vinyl versatate. Such as vinyl ester; (meth) acrylonitrile; vinyl chloride and other halogenated vinyls; diethyl fumarate, dibutyl fumarate, di (2-ethylhexyl) fumarate and other fumaric acid esters, and their corresponding maleic acid esters. Le and the like.

Preferred vinyl monomers include (meth) acrylic acid; alkyl having about 1 to 12 carbon atoms such as methyl methacrylate, ethyl (meth) acrylate, butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate. An alkyl (meth) acrylate having a group;
(Meth) acrylate having a hydroxyl group; (meth) acrylate having a glycidyl group; styrene and the like are included.

The vinyl-based monomer has a glass transition temperature (Tg) of 30 ° C. or higher as a whole, preferably 50 to 125.
It is selected so as to form a polymer at about [deg.] C, more preferably about 75 to 120 [deg.] C. The glass transition temperature of the polymer can be adjusted by appropriately selecting the type of the monomer and homopolymerizing or copolymerizing it. For example, the glass transition temperature 7
Monomers that form a rigid polymer at about 0 ° C to 130 ° C (for example, (meth) acrylic acid, methyl methacrylate,
Styrene, acrylonitrile) and glass transition temperature 60
Adjusted by copolymerizing in combination with a monomer that forms a soft polymer at a temperature of ℃ or less (for example, an acrylate having an alkyl group having about 2 to 12 carbon atoms, a (meth) acrylate having a hydroxyl group or a glycidyl group). May be.

The polymer composed of vinyl monomers, especially the polymer constituting the backbone of the silicone macromonomer copolymer, is mainly composed of (meth) acrylic monomers (for example, 50 to 100% by weight). ) Is preferred. Further, in order to improve the compatibility with the olefin polymer (a), the polymer constituting the trunk portion in the silicone macromonomer copolymer is
A polymer mainly composed of a (meth) acrylic monomer and styrene is preferable. The ratio of the (meth) acrylic monomer and styrene is, for example, 10 to 90/90.
-10 (wt%), preferably 25-75 / 75-25
(% By weight).

The organosiloxane macromonomer is
It often has a polyorganosiloxane chain and a polymerizable functional group. The polyorganosiloxane chain can be composed of a polyalkylsiloxane such as polydimethylsiloxane, a polyarylsiloxane such as polydiphenylsiloxane, or a polyalkylarylsiloxane. The molecular weight of the polyorganosiloxane chain can be appropriately selected and is, for example, 100 to 25,000, preferably 1,000.
It is about 10,000. The polymerizable functional group is often located at the terminal of the macromonomer, and an active group corresponding to the reactive functional group of the polymer, for example, a vinyl group, a (meth) acryloyl group, an amino group, a halogen atom, a methoxy group, etc. It is often an alkoxy group, a mercapto group, a glycidyl group, an epoxy group, or the like.

The molecular weight of the silicone-based macromonomer copolymer is not particularly limited, but is, for example, 1000 to 50.
000, preferably 3000 to 30000, and more preferably 5000 to 20000. The content of the polyorganosiloxane unit in the silicone-based macromonomer copolymer is usually 10 to 50% by weight, preferably about 25 to 45% by weight.

The melt flow index (MI) of the silicone-based macromonomer copolymer at 230 ° C. is 10 to 100 g / 10 minutes, preferably 20 to enhance the compatibility with the olefin polymer (a).
It is about 75 g / 10 minutes.

The silicone-based macromonomer copolymer is
It can be obtained by radical polymerization of the vinyl monomer and the organosiloxane macromonomer by a conventional method. The comb-shaped graft polymer can be obtained by graft-polymerizing the vinyl monomer polymer and the organosiloxane macromonomer.

The silicone-based macromonomer copolymer is
It may have a residue such as a hydroxyl group or a carboxyl group derived from the polymer of the vinyl monomer.

In the graft polymerization, when the organosiloxane macromonomer has a polymerizable unsaturated bond such as a vinyl group or a (meth) acryloyl group, it can be graft polymerized by a conventional polymerization reaction. In addition, the organosiloxane macromonomer has an amino group,
When it has a halogen atom, an alkoxy group, a mercapto group, a glycidyl group, an epoxy group, or the like, it can be obtained by condensation or addition polymerization with a polymer having a functional group that undergoes condensation or addition reaction with these reactive groups.

The polymerization reaction is carried out in a solvent inert to the reaction, for example, aromatic hydrocarbons such as benzene, toluene and xylene; alcohols such as isopropyl alcohol; cellosolves; esters such as ethyl acetate and butyl acetate;
It may be carried out in a solvent such as ketones such as methyl ethyl ketone and methyl isobutyl ketone.

The silicone-based macromonomer copolymer, especially the comb-shaped graft polymer, has a silicone chain excellent in slipperiness, releasability and heat resistance, and a polymer chain excellent in adhesion, printability and printability (preferably a main chain). Has an acrylic chain) and has the characteristic that these contradictory properties can be compatible. The silicone-based macromonomer copolymer is
It is usually a polymer that is solid at room temperature. Therefore, unlike the silicone oil and the silicone gum, the silicone-based macromonomer copolymer has no migration property to the surface.

The content of the silicone-based macromonomer copolymer in the coating layer can be appropriately selected depending on the content of the organosiloxane and the like so that the wrapping property of the film can be enhanced. The content of the silicone-based macromonomer copolymer is, for example, 0.1 to 10% by weight, preferably 0.5 to 7.5% by weight, more preferably 1 to 5% by weight. If the content of the silicone-based macromonomer copolymer is less than 0.1% by weight, the slipperiness and releasability of the film are deteriorated, and if it exceeds 10% by weight, the heat-sealable temperature shifts to the high temperature side, and the sealing Defects are likely to occur.

The content of the silicone macromonomer copolymer in the coating layer is, for example, 0.1 to 5% by weight, preferably 0.2 to 3% by weight as polyorganosiloxane.
%, And more preferably about 0.3 to 2% by weight.

The coating layer may contain various additives that can be added to the base film layer. Especially 100 ℃
It is useful to add an antiblocking agent, wax, etc. in order to improve the slipperiness under the following low temperature and low load. As the anti-blocking agent, fine powder having heat resistance higher than the film forming temperature, for example, fine powder such as fine powder silica (especially inorganic fine powder having an average particle size of about 1 to 5 μm), spherical heat-resistant resin fine powder (For example, a crosslinked acrylic resin or benzoguanamine resin having an average particle size of about 1 to 6 μm) can be used, and as the wax, an acid amide such as stearic acid amide or erucic acid amide can be used. The use of the anti-blocking agent and / or the wax, in combination with the action of the thermoplastic silicone elastomer, makes it possible to smoothly carry out the overlapping packaging at a higher speed. The antiblocking agent and the wax are each added in an amount of, for example, 0.05 to 5% by weight, preferably 0.1 to 3% by weight.

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, 1.0 μm or less, preferably 0.1 to 0.7 μm, more preferably 0.3 to.
It is about 0.7 μm. When the thickness of the coating layer exceeds 1 μm, the releasability from the metal guide plate is deteriorated, and high-speed packaging may not be performed stably.

The composite film composed of the base film layer and the coating layer may be unstretched, but 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, flame treatment and high frequency treatment, if necessary. In the preferred composite film, the surface of the base film opposite to the coating layer and the surface of the coating layer containing no silicone-based macromonomer copolymer are subjected to a surface treatment, and have a surface area of 38 dyne / cm or more, preferably about 40 to 42 dyne / cm. It has a surface tension of.

The composite film of the present invention can be obtained by laminating (2) a polymer layer containing an olefin polymer and a silicone macromonomer copolymer on (1) a base film layer. More specifically, the composite film can be obtained by a dry laminating method, an extrusion laminating method or a co-extrusion molding method. The preferred method is the coextrusion method.

In the dry lamination method, the surface of at least one of (1) the base film layer and (2) the polymer layer containing the olefin polymer and the silicone macromonomer copolymer is coated with, for example, a titanium anchor. It can be performed by treating with an anchor coating agent such as a coating agent, a polyethyleneimine-based anchor coating agent, a urethane-based anchor coating agent, etc., and laminating. In the dry laminating method, stretched films can be used as the (1) base film layer and the (2) polymer layer.

In the coextrusion molding method, (1)
It can be obtained by co-extruding the polymer composition constituting the base film layer and the polymer composition containing (2) the olefin polymer and the silicone macromonomer copolymer. The extruded composite film is preferably subjected to a stretching step.

The coextrusion molding can be carried out according to a conventional method. For example, in an extruder equipped with a T-die, a ring die, etc., (1) a polymer composition constituting the base film layer, and (2) a polymer composition containing an olefin polymer and a silicone macromonomer copolymer. And are individually charged and melt-extruded into a die by an extruder. Polymer composition (1) in the flow path in the die
The layers of (2) are merged and laminated, and melt extruded from a die,
A composite film is obtained by cooling.

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, and at least one draw ratio is 4 to 10 times, preferably about 6 to 10 times.

Various coating layers and laminating layers may be formed on the composite film of the present invention depending on the type of the base film layer and the application. 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) On at least one surface of the polypropylene film layer, at least one ethylene-based copolymer having heat sealability (for example, at least one of ethylene-propylene copolymer and ethylene-propylene-butene-1 copolymer) is used. A composite film in which a coating layer containing an ethylene-based copolymer) and a silicone-based macromonomer copolymer (particularly a comb-shaped graft copolymer) is laminated and biaxially stretched.

(B) At least one surface of the polypropylene film layer has at least one ethylene copolymer having heat sealability (for example, at least one of ethylene-propylene copolymer and ethylene-propylene-butene-1 copolymer). (Ethylene-based copolymer) and silicone-based macromonomer copolymer (particularly comb-shaped graft copolymer) are laminated, and the other surface is coated with an ethylene-based copolymer having heat sealability. A composite film in which layers are laminated and biaxially stretched.

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

(D) A composite film in which the ethylene-based copolymer is an ethylene-propylene-butene-1 copolymer having an ethylene content of 0.5 to 5% by weight and a butene-1 content of 3 to 25% by weight.

(E) A composite film in which the coating layer contains an antiblocking agent, preferably a fine powdery antiblocking agent.

(F) The silicone macromonomer copolymer is a graft in which a polyorganosiloxane macromonomer is graft-polymerized in a comb shape on a polymer (preferably having a glass transition temperature of 50 to 125 ° C.) containing a structural unit of an acrylic monomer. A composite film that is a copolymer.

The present specification also discloses an overlapping method in which the composite film is used to package articles at a rate of 300 pieces / minute or more.

[0066]

In the composite film of the present invention, since the coating layer contains the olefin polymer and the silicone macromonomer copolymer, the composite film can package the article at a high speed.

Further, the composite film has high slipperiness, releasability and antistatic property. Therefore, the article can be packaged at high speed by the automatic wrapping machine for overlapping, and is excellent in printability, printability and lamination suitability.

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

[0069]

EXAMPLES The present invention will be described in more detail based on the following examples.

Example 1 Raw material (A) for base polymer layer and raw material (B) for coating layer
1) The following composition was used as (C1).

Raw material (A) for the base polymer layer: 90 parts by weight of isotactic polypropylene (manufactured by Sumitomo Chemical Co., Ltd., trade name FS2011D, isotactic index 94%), 10 parts by weight of petroleum resin, and alkylamine A mixture of ethylene oxide adduct and 0.5 part by weight of stearic acid monoglyceride mixture.

Raw material (B1) for the first coating layer: ethylene-
100 parts by weight of a propylene-butene-1 random copolymer (Sumitomo Chemical Co., Ltd., trade name WF715N), a silicone comb type acrylic graft copolymer by the macromonomer method (Toa Gosei Chemical Industry Co., Ltd., Product name Cymac XSD-23, molecular weight 15000, melt flow index at 230 ° C. 35 g / 10 minutes, content of polyorganosiloxane unit 30% by weight) 4.0 parts by weight, fine powder silica 0.4 with an average particle size of 4 μm 0.4 A mixture of parts by weight and 0.3 parts by weight of erucamide.

Raw material (C1) for the second coating layer: A mixture obtained by removing the comb-type acrylic graft copolymer from the raw material (B1) for the first coating layer.

The above raw materials (A), (B1) and (C1) are respectively supplied to an extrusion molding machine equipped with a T die, and 220 to 2 are supplied.
Coextrusion at a temperature of 30 ° C, layer structure B1 / A / C
A sheet of 3 types and 3 layers of No. 1 was produced. The obtained sheet,
6 times in the longitudinal direction with a roll of 115 to 125 ° C., stretched in the width direction at a temperature of 160 ° C., then heat-treated at 160 ° C. for 10 seconds, and the surface of the C1 layer of the film is subjected to corona discharge treatment, A seed 3 layer composite film was prepared. The surface tension of the corona discharge treated surface is 39 dyne / cm,
The thickness of the obtained composite film was 22 μm (A layer thickness 2
0 μm, B1 layer thickness 0.5 μm, C1 layer thickness 1.0
μm).

Example 2 3 was carried out in the same manner as in Example 1 except that the following raw material (B2) was used instead of the raw material (B1) for the first coating layer of Example 1.
A seed 3 layer composite film was prepared.

Raw material (B2) for the first coating layer: ethylene-
Propylene copolymer (Sumitomo Chemical Co., Ltd., trade name F
L6711N) 75 parts by weight, a random polymer of ethylene-propylene-butene-1 (manufactured by Sumitomo Chemical Co., Ltd., product name WS709N) 25 parts by weight, silicone comb-type acrylic graft copolymer by the macromonomer method (Toagosei) Chemical Industry Co., Ltd., trade name Cymac XSD-24,
Melt flow at a molecular weight of 15,000 and 230 ° C
Index 25 g / 10 minutes, content of polyorganosiloxane unit 40% by weight) 2.0 parts by weight, average particle size 4 μm
A mixture of 0.4 parts by weight of finely divided silica and 0.5 part by weight of erucic acid amide.

Comparative Example 1 A layer was prepared in the same manner as in Example 1 except that the raw material (C1) for the coating layer used in Example 1 was used instead of the raw material (B1) for the first coating layer in Example 1. 3 types with structure C1 / A / C1 3
A composite film of layers was made.

Comparative Example 2 A composite of three kinds of three layers was prepared in the same manner as in Example 1 except that the following raw material (B3) for the coating layer was used in place of the raw material (B1) for the first coating layer in Example 1. A film was made.

Raw material (B3) for the first coating layer: ethylene
100 parts by weight of a propylene-butene-1 random polymer (Sumitomo Chemical Co., Ltd., trade name WF715N), 1.2 parts by weight of dimethylpolysiloxane (average molecular weight 1 × 10 ⁵ ) and fine powder having an average particle size of 4 μm. A mixture of 0.4 parts by weight silica and 0.3 parts by weight erucamide.

Then, the high-speed overlapping packaging suitability, printability, and writing suitability with an oil-based magic ink of the composite films obtained in Examples and Comparative Examples were evaluated as follows.

High-speed overlapping packaging suitability: A carton containing 20 cigarettes is automatically wrapped by an automatic wrapping machine (Tokyo Automatic Machinery Co., Ltd., W323 type).
Was used to automatically package each composite film. Packaging is 2
Under the conditions of 0 ° C. and 55% RH, packaging was performed for 2 minutes at a packaging speed of 300 pieces / minute, and the packaging suitability was evaluated according to the following criteria.

(1) Adhesion of film to metal guide plate Excellent: No adhesion No: Adhesion (2) Number of packages that can be packaged before the machine is stopped because the film is stuck in the packaging machine (3) End of packaging Sealability of the sealed part of the package afterward Excellent: Sealed Not possible: Not sealed Printing suitability and writing suitability with oil-based magic ink: (1) Printing suitability A thermal transfer type printing machine was added to the overlapping automatic packaging machine. After mounting, the film was fed out at a speed of 60 m / min, the date was printed at 190 ° C., and the printability was evaluated according to the following criteria. A ribbon for a cigarette packaging film (manufactured by BG1) was used as the printing ribbon.

Excellent: The date was printed without being repelled by the printing ink and could be read clearly. No: The date was repelled and could not be read clearly. (2) Writing suitability with oil-based magic ink. Write down on the film,
Writability was evaluated according to the following criteria.

Excellent: Magic ink is not repelled at all and clear writing is possible. Poor: Magic ink is repelled and the written portion becomes unclear. The results are shown in the table.

[0085]

[Table 1] As is clear from the table, the composite films obtained in Example 1 and Example 2 are excellent in packaging suitability, antistatic property and heat sealing property, and have no trouble even when packaged at a high speed of 300 pieces / minute. The packaging was smooth. Further, the printing ink and the oil-based magic ink did not repel, and clear printing and writing were possible.

On the other hand, the composite film obtained in Comparative Example 1 had poor slipperiness and releasability, and the automatic packaging machine stopped when 20 cigarettes were packaged. The composite film obtained in Comparative Example 2 was capable of high-speed packaging, but the date marking after packaging was unclear, and the oil-based magic ink repelled, and writing was not possible.

Claims (8)

[Claims] 1. A coating layer containing (2) an olefin-based polymer and a copolymer of a vinyl-based monomer and an organosiloxane-based macromonomer is laminated on at least one surface of a base film layer (1). Composite film. 2. The composite film according to claim 1, wherein the base film layer is made of polypropylene, and the film is stretched. 3. The composite film according to claim 3, wherein the olefin polymer in the coating layer is at least one ethylene copolymer of ethylene-propylene copolymer and ethylene-propylene-butene-1 copolymer. 4. The content of a copolymer of a vinyl monomer and an organosiloxane macromonomer in the coating layer is 0.1.
The composite film according to claim 1, which is 10% by weight. 5. The content of a copolymer of a vinyl monomer and an organosiloxane macromonomer in the coating layer is 0.1 to 5% by weight as an organosiloxane.
The composite film described. 6. The composite film according to claim 1, wherein the melt flow index at 230 ° C. of the copolymer of a vinyl monomer and an organosiloxane macromonomer is 10 to 100 g / 10 minutes. 7. The composite film according to claim 1, wherein the coating layer has a thickness of 1.0 μm or less. 8. (1) A polymer layer containing (2) an olefin polymer and a copolymer of a vinyl monomer and an organosiloxane macromonomer is laminated on at least one surface of a base film layer. Manufacturing method of composite film.