JP2000129016A - Production of polyolefin composite film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing a polyolefin film desirable as a gas barrier film. SOLUTION: One surface of a polyolefin base film containing 0.1-1 pt.wt. antistatic agent is subjected to a corona discharge treatment to a wetting index of 35-45 mN/m to form a treated surface A, the other surface is subjected to a corona discharge treatment in an atmosphere of nitrogen and/or carbon dioxide to a wetting index of 40-55 mN/m to form a treated surface B, and the surface B is laminated with a resin layer based on an ethylene/vinyl alcohol copolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a polyolefin-based packaging film, and more particularly to a method for producing a polyolefin-based film suitable as a gas barrier film.

[0002]

2. Description of the Related Art Polyolefin films, such as polypropylene films, are widely packaged due to their good workability due to their thermoplasticity and their excellent secondary strength such as excellent mechanical strength, transparency, and bag-making properties. It is widely used as a film.

Conventionally, on the surface of a polyolefin film,
Lamination of an ethylene-vinyl alcohol copolymer (hereinafter referred to as EvOH) has been carried out for the purpose of imparting functions such as gas barrier properties. At the expense of reduction and cost increase, an adhesive layer such as an anchor coat agent is generally provided.

In order to solve the above problem, a method has been proposed in which the surface of a base film made of a thermoplastic resin film is subjected to a corona discharge treatment so as to improve the adhesion at the time of laminating EvOH without providing an anchor coat layer. ing.

[0005] For example, a method in which a base film using a PET film or a nylon film as a thermoplastic resin is subjected to corona treatment in air, and then EvOH is laminated, In general, a method has been proposed in which a corona discharge treatment is performed in a nitrogen gas atmosphere or a nitrogen / carbon dioxide gas atmosphere, and a layer of a water-soluble polymer such as EvOH is laminated on the surface-treated surface.

When the above method is applied to a polyolefin base film represented by polypropylene, EvOH
The effect of improving the adhesiveness when laminating is certainly improved. In particular, those subjected to corona discharge treatment in a nitrogen gas atmosphere or a nitrogen / carbon dioxide gas atmosphere have a remarkable effect of improving the adhesive strength.

[0007]

However, the corona discharge-treated surface of the polyolefin-based film having improved adhesion as described above tends to cause blocking between the films during handling before lamination of EvOH.
Not only does the productivity of the composite film decrease, but there is a problem that a fatal trouble such as breakage or entanglement of the film occurs.

For example, as a method of laminating a composite film, generally, off-line coating is often used. In this case, the polyolefin base film is wound around a roll once after corona discharge treatment, and then the EvOH film is again rolled from the roll. It is drawn out to the lamination process. Then, at the time of such withdrawal, a problem occurs due to the blocking.

[0009] Even after the above-mentioned lamination, on the opposite side of the substrate film on which the gas barrier layer of EvOH or the like is not laminated, the film is repeatedly charged and extracted several times, so that the film is charged, and the adhesion of dust and the like is prevented. There is also a problem that it becomes a problem.

Therefore, an object of the present invention is to provide a specific surface treatment to the surface of a polyolefin base film,
In the base film and the resin layer containing EvOH as a main component, not only is it possible to form a treated surface for obtaining strong adhesiveness without using an adhesive layer such as an anchor coat agent, but also a polyolefin substrate having the treated surface. Ev using film
An object of the present invention is to provide a method for producing a composite film in which OH is laminated without causing a problem of blocking between polyolefin base films.

[0011]

Means for Solving the Problems The present inventors have developed a method for laminating a polyolefin substrate film and a resin layer containing EvOH as a main component with strong adhesion, together with a method for treating the polyolefin substrate film. In order to establish a method for achieving both good antistatic properties and good blocking resistance in the handling of polyolefin-based films, intensive studies have been made.

As a result, one surface of the polyolefin substrate film containing the antistatic agent is subjected to a moderately weak corona discharge treatment, and the other surface is subjected to a relatively strong corona discharge treatment under specific conditions to thereby reduce the laminated surface of EvOH. After formation, it was found that the above-mentioned problems could be solved by laminating EvOH on the polyolefin base film, and the present invention was completed.

That is, according to the present invention, a surface of a polyolefin substrate film containing 0.1 to 1 part by weight of an antistatic agent is subjected to a corona discharge treatment so as to have a wetting index of 35 to 45 mN / m. Is formed, and a wetting index of 40 to
After performing a corona discharge treatment under a nitrogen and / or carbon dioxide gas atmosphere to form a treated surface B at 55 mN / m, the surface-treated surface B is mainly composed of an ethylene-vinyl alcohol copolymer. A method for producing a polyolefin composite film, comprising laminating resin layers.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a polyolefin substrate film mainly imparts mechanical properties and film secondary processing properties to a composite film to be obtained. The various polyolefin films used are used without any particular limitation.

As the polyolefin, specifically, polypropylene, polyethylene, polybutene, etc.
Species or two or more polymers are exemplified. More specifically, propylene homopolymer, ethylene-propylene copolymer, ethylene-propylene-butene copolymer, propylene-olefin copolymer, high-density polyethylene, low-density polyethylene, ethylene-olefin copolymer, Examples thereof include polybutene and a butene-olefin copolymer. Among these, ethylene and olefins other than propylene include, for example, 1-butene, 1-pentene,
One or more α-olefins such as 1-hexene, 1-heptene and 4-methyl-1-pentene can be suitably used.

Among these, in consideration of heat resistance, film forming property, etc., a polypropylene resin containing propylene as a main component is preferable. Specifically, propylene homopolymer, ethylene other than propylene and propylene, 1-butene, 1-pentene, 1-hexene, random or block copolymer with α-olefin such as 4-methyl-1-pentene,
Further, a mixture of these polymers may be mentioned, and among them,
Preferred are a propylene homopolymer, a propylene-ethylene random copolymer, and a propylene-ethylene-butene random copolymer.

As the method for producing the polypropylene resin, known methods can be used without any limitation.
A method of polymerizing the above-mentioned monomer using a known polymerization catalyst for polypropylene, such as iCl ₃ -supported TiCl _{3 or} a metallocene catalyst, may be used. Further, after polymerization using the above catalyst, a method of decomposing with a peroxide or the like may be performed.

The melting point of the polypropylene-based resin is determined by measuring the peak-top value in a differential scanning calorimetry (hereinafter, referred to as DSC) as follows:
To 165 ° C, more preferably 135 to 165 ° C. Further, the melt flow rate (hereinafter referred to as MFR) is set at 0.
1 to 10 g / 10 min, preferably 0.5 to 5 g
g / 10 minutes is more preferable.

Further, other resins can be mixed with the above polypropylene resin to such an extent that the effects of the present invention are not impaired. Other resins to be mixed are not particularly limited, but generally, polyolefin resins such as one or more homopolymers and copolymers such as polypropylene, polyethylene, and polybutene, polyolefin-based wax, polyolefin-based elastomer, Or petroleum resin, hydrocarbon resin such as terpene resin, ethylene and vinyl acetate, acrylate, copolymer of acrylate monomer,
Alternatively, it is preferable to select from a mixture of two or more of these polymers.

In the present invention, when the polyolefin base film is a polypropylene resin, the base film may be a single-layer film or a composite film. Specifically, a single-layer film mainly composed of propylene homopolymer, a layer mainly composed of propylene homopolymer,
A composite film with a layer mainly composed of a random copolymer of propylene and an α-olefin other than propylene is exemplified.

The polyolefin substrate film of the present invention comprises
Any of unstretched, uniaxially stretched, and biaxially stretched may be used, but in consideration of mechanical properties, secondary workability, and the like, a biaxially stretched film is preferable. Although the thickness of the substrate film is not particularly limited, it is generally appropriately selected in the range of 1 to 500 μm.

The polyolefin base film of the present invention needs to contain a specific amount of an antistatic agent in order to impart a suitable antistatic property by the action with the treated surface A described later. In other words, the content of the antistatic agent is
It is necessary to be 0.1 to 1 part by weight, preferably 0.15 to 0.8 part by weight, based on 0 part by weight.
When the content of the antistatic agent is less than 0.1 part by weight,
If the antistatic effect is not sufficient and exceeds 1 part by weight, E
It is not preferable because adhesion to a resin layer containing vOH as a main component is reduced and blocking occurs between surface-treated polyolefin base films.

Known antistatic agents are used without particular limitation. Specific examples include fatty acid esters of polyhydric alcohols such as glycerin fatty acid ester, sorbitan fatty acid ester, pentaerythritol fatty acid ester, polyethylene glycol fatty acid ester, polyglycerin fatty acid ester, alkylamine such as alkyldiethanolamine and alkyldiethanolamine fatty acid ester, and diethanolamine. And alkyldiethanolamides and fatty acid salts of alkylbenzenes comprising fatty acids.

Among these, considering antistatic properties and anti-blocking properties, glycerin fatty acid ester, sorbitan fatty acid ester, alkyldiethanolamine,
It is preferable to combine one or more of alkyl diethanolamine fatty acid esters and alkyl diethanolamides, and a combination of glycerin fatty acid ester / alkyldiethanolamide, glycerin fatty acid ester / alkyldiethanolamine / alkyldiethanolamine fatty acid ester is preferable.

Further, considering uniform coatability with a water / lower alcohol solution or dispersion coating solution, alkyldiethanolamide alone or a combination of glycerin fatty acid ester / alkyldiethanolamide is more preferable.

The number of carbon atoms in the alkyl group of the above fatty acid and alkylamine is 6 to 6 in consideration of antistatic property, adhesiveness and the like.
It is preferably 22 and more preferably 12 to 20.

Generally, it is preferable to add a slip agent such as fatty acid amide to the polyolefin film. The content of the fatty acid amide is preferably 1 part by weight or less based on 100 parts by weight of the resin.
More preferably, the amount is not more than part by weight. When the amount is more than 1 part by weight, the adhesiveness to a resin layer containing EvOH as a main component is undesirably reduced.

Specific examples of such fatty acid amides include lauric amide, myristic amide, palmitic amide, oleic amide, erucic amide and the like.

In order to prevent blocking of the resulting polyolefin composite film, an antiblocking agent is preferably incorporated into the polyolefin film. The amount of the anti-blocking agent is 0.01 to 0.5 parts by weight based on 100 parts by weight of the resin when the base film is a single-layer film in consideration of the appearance, transparency and anti-blocking properties of the film. Preferably,
More preferably, the amount is 0.03 to 0.3 parts by weight. When the base film is a composite film, it is necessary to add an antiblocking agent to the surface layer, and the above amount may be added to 100 parts by weight of the surface layer resin.

As the antiblocking agent, generally known ones such as inorganic substances and organic polymers are used without any restriction. Specifically, silica, silica-alumina,
Composite oxide containing silica such as silica-zirconia and silica-titania as a main component, for example, 50 mol% or more, or a molten inorganic oxide thereof, inorganic fine particles such as calcium carbonate, silicone resin particles, silicone rubber particles, and polyamide particles And organic fine particles such as condensed resin particles having a triazine ring, polyacrylate particles, polymethacrylate particles, and polystyrene particles. These fine particles may be amorphous or spherical, and even if they have a crosslinked structure to improve heat resistance, they have been subjected to a surface treatment to control the hydrophilicity / hydrophobicity of the surface. May be. Among these, condensed spherical resin particles having a triazine ring and polymethyl methacrylate spherical particles are preferable in consideration of the appearance and transparency of the film, and polymethyl methacrylate spherical particles are more preferable in consideration of blocking properties.

The average particle size of the anti-blocking agent is determined in consideration of the transparency of the film, the anti-blocking property, and the like.
It is preferably from 0.5 to 5 μm, more preferably from 1 to 3 μm. The blending amount depends on the transparency of the film,
In consideration of anti-blocking properties, the amount is preferably 0.01 to 1 part by weight, more preferably 0.03 to 0.5 part by weight.

The polyolefin substrate film of the present invention may contain other additives such as an antioxidant, a light stabilizer and a crystal nucleating agent in an amount which does not impair the effects of the present invention, if necessary. May be added.

The polyolefin substrate film of the present invention comprises:
It is preferable that the film is transparent in consideration of its use for packaging, particularly as a gas barrier film, and the haze value is preferably 15% or less, more preferably 10% or less.

In the present invention, the surface of the base film on which the resin layer mainly composed of EvOH is laminated has a specific corona discharge so as to have a specific wetting index so as to realize a high degree of adhesion to the resin layer. It is necessary to take action.

That is, the atmosphere during the corona discharge treatment is as follows:
The atmosphere needs to be a nitrogen and / or carbon dioxide gas atmosphere, and is preferably a nitrogen atmosphere in consideration of economy. The oxygen concentration in the substantial nitrogen and / or carbon dioxide gas atmosphere is preferably 5% by volume or less, and preferably 3% by volume or less, in consideration of the adhesion to the resin layer containing EvOH as a main component. More preferred. Also,
Although the corona discharge treatment density is not particularly limited, it is 5 to 100.
W · min / m ² , preferably 10 to 70 W
More preferably, it is min / m ² . That is, when the processing density is lower than 5 W · min / m ² , the adhesion to the resin layer containing EvOH as a main component is unfavorably reduced, and when the processing density is higher than 100 W · min / m ² , the polyolefin base film is used. This is not preferable because blocking occurs between the films and processing unevenness having different processing degrees occurs in the width direction of the film.

In the present invention, it is necessary to adjust the above conditions so that the wetting index of the treated surface B obtained by the above treatment is 40 to 55 mN / m in order to realize high adhesiveness. The wetting index is 45 to 50 m
More preferably, it is N / m. If the wetting index is less than 40 mN / m, the adhesiveness to the resin layer containing EvOH as a main component decreases, which is not preferable.
When it is higher than 5 mN / m, even when the wetting index is adjusted to a specific range in the formation of the treated surface A described later, blocking between the polyolefin base films is likely to occur, and in the width direction of the film. Thus, processing unevenness with different processing degrees occurs. And the processing unevenness is
This may cause uneven coating and uneven adhesive strength during coating.

In the present invention, the surface roughness (Ra value) of the treated surface B of the polyolefin substrate film is preferably 0.5 to 100 nm, and more preferably 1 to 80 nm, in consideration of adhesiveness. More preferably, 3 to
More preferably, it is 50 nm.

In the present invention, the surface of the base film on which the resin layer containing EvOH as a main component is not laminated is imparted with an appropriate antistatic property for suppressing the adhesion of dust as a packaging film, and the polyolefin base film is not laminated. In order to reduce the blocking property, it is necessary to perform corona discharge treatment so as to have a specific wetting index.

The above-mentioned corona discharge treatment is carried out, for example, by passing the substrate film through the generated corona atmosphere using a known corona discharge treatment machine. The atmosphere during the corona discharge treatment is preferably an air atmosphere or a nitrogen and / or carbon dioxide gas atmosphere, and is preferably an air atmosphere or a nitrogen atmosphere in consideration of economy.

The corona discharge treatment density calculated by voltage × current / (electrode width × film running speed) (W · min / m ² ) is preferably 1 to 70 W · min / m ^2. More preferably, it is で 50 W · min / m ² . If the processing density is lower than 1 W · min / m ² , the antistatic property is undesirably reduced,
When it is higher than 0 W · min / m ² , it is not preferable because blocking between polyolefin base films occurs.

In the present invention, it is important that the treatment surface A obtained by the treatment described above has a wetting index of 35 to 45 mN / m, and more preferably 38 to 43 mN / m. That is, the treatment surface A has a wetting index of 3
If it is less than 5 mN / m, it is not preferable because the antistatic property is reduced, and if it is more than 45 mN / m, it is not preferable because blocking occurs between base films.

Conventionally, for the purpose of improving the adhesiveness to cellophane ink containing a nitrocellulose resin,
A method has been proposed in which the surface of a polypropylene base film containing a fatty acid monoglyceride is subjected to a corona discharge treatment under a substantially nitrogen atmosphere, but such a method is not described at all for the corona treatment on the opposite surface of the film. In addition, in this aspect, the effect of preventing the blocking by the addition of the fatty acid monoglyceride is not sufficient.

In the present invention, the processing surface A and the processing surface B
Although the order of forming is not particularly limited, it is preferable to form the processing surface A first and then form the processing surface B.

In the present invention, as the ethylene-vinyl alcohol copolymer, a known product obtained by saponifying a copolymer of ethylene and vinyl acetate can be used without any particular limitation. Among them, ethylene content is 15-60
Mol% is preferable, and 20 to 50 mol% is particularly preferable. When the ethylene content is lower than 15 mol%, the adhesiveness to the base film decreases, and when it is higher than 60 mol%, the gas barrier property decreases, which is not preferable. The degree of saponification of the vinyl acetate component is preferably at least 90 mol%, more preferably at least 95 mol%, in consideration of gas barrier properties.

The copolymer comprises a small amount of propylene,
It may also contain comonomers such as olefins such as isobutene and octene, unsaturated carboxylic acids or salts thereof, partial alkyl esters, complete alkyl esters, nitriles, amides, anhydrides, unsaturated sulfonic acids and salts thereof.

In the resin layer containing EvOH as a main component used in the present invention, the mixing ratio of the above EvOH is preferably 40 wt% or more, considering the gas barrier properties and the effects of the present invention, and is preferably 50 wt% or more. It is more preferably at least 60 wt%, and even more preferably at least 60 wt%.
The components other than EvOH are not particularly limited, but include inorganic compounds such as inorganic fine particles and inorganic layered compounds. Specifically, inorganic fine particles such as kaolin, calcium carbonate, titanium oxide, silicon oxide, alumina, barium sulfate, calcium fluoride, lithium fluoride, zirconia, calcium phosphate, montmorillonite, kaolinite, halloysite, vermiculite, dickite, nacrite, Inorganic layered compounds such as antigorite, vilophilite, hectorite, beidellite, margarite, talc, tetrasilyl mica, muscovite, phlogopite, and chlorite.

The inorganic compound and EvOH may be in a state of being dispersed and mixed with each other, or may be in a state of being crosslinked with a crosslinking agent or the like. Further, siloxane bonds were formed two-dimensionally or three-dimensionally by a sol-gel method or the like between the molecular chains of the EvOH polymer and / or on the surface of the water-soluble polymer opposite to the surface contacting the base film. It may be something. The crosslinking agent is not particularly limited, but specifically,
Titanium coupling agent, silane coupling agent, melamine coupling agent, epoxy coupling agent,
Examples include isocyanate-based coupling agents, copper compounds, zirconia compounds, and the like.

The thickness of the resin layer containing EvOH as a main component in the present invention is not particularly limited, but is preferably 0.1 to 10 μm in consideration of gas barrier properties.
More preferably, it is 3 to 6 μm.

As the method for forming the polyolefin substrate film, known methods can be used without limitation. Specific examples include a T-die method and a tubular method in which a polyolefin is melt-extruded and then cooled to obtain an unstretched film, and a method of further stretching to obtain a stretched film. Considering mechanical properties and the like, it is preferable that the film is a stretched film. Examples of the stretching method include a longitudinal or transverse uniaxial stretching method, a longitudinal and transverse sequential biaxial stretching method, a simultaneous biaxial stretching method, a rolling method, and a method of successively stretching a sheet formed by calendering in at least one direction. Among these stretching methods, in consideration of thickness / thinness accuracy, mechanical properties, and the like, a longitudinal and transverse sequential biaxial stretching method and a tenter method simultaneous biaxial stretching method are preferable.

In the present invention, as a laminating method for laminating a resin layer containing EvOH as a main component on a polyolefin base film, a concrete example is an extrusion laminating method, in which a molten resin is laminated on a vertically uniaxially stretched sheet. An in-line laminating method in which lateral stretching is performed afterward, a solution or solvent dispersion coating method, and the like can be given. Among these, considering that high-speed thin film coating is used, gravure coating, reverse coating, spray coating, kiss coating, die coating, metalling, etc. are applied to a coating solution in which a resin containing EvOH as a main component is dissolved or dispersed in various solvents. It is preferable to perform gravure coating in combination with bar coating and chamber doctor. In the coating method, either in-line coating or off-line coating, in which the film is coated on a longitudinally uniaxially stretched sheet and then horizontally stretched, or subsequently coated after stretching, may be employed. Off-line coating is preferred in consideration of easy control of drying conditions and small turn.

The coating solution containing a resin containing EvOH as a main component is preferably a coating solution in which the resin component is uniformly dissolved or dispersed in a solvent. As a solvent, a mixed solvent of water / lower alcohol is used. As a lower alcohol,
It is an alcoholic compound having 1 to 3 carbon atoms, and specifically, methanol, ethanol, n- or iso-propanol is preferred. The mixing ratio of water / alcohol is appropriately selected from the range of 10/90 to 90/10 by weight, and
It is preferably 0/70 to 70/30.

Further, other water-soluble organic compounds may be added to the above-mentioned coating solution in order to enhance the suitability for coating the polyolefin base film, as long as the stability of the coating solution is not impaired. Specifically, in addition to the lower alcohols used as the solvent, glycols such as ethylene glycol and propylene glycol, glycol derivatives such as methyl cellosolve, ethyl cellosolve, and n-butyl cellosolve, and polyhydric alcohols such as glycerin and waxes And ethers such as dioxane and trioxane; esters such as ethyl acetate; ketones such as methyl ethyl ketone; and aqueous anchor coating agents such as aqueous isocyanate, polyethyleneimine and epoxy resin.

The pH of the coating solution is preferably 2 to 11 in consideration of the stability of the coating solution.

The method for preparing the coating liquid is not particularly limited, but may be a method in which EvOH is uniformly dissolved or dispersed in a solvent, and then mixed with a liquid in which components other than EvOH are uniformly dissolved or dispersed. No.

Although the use of the composite film of the present invention is not particularly limited, it is suitable as a food packaging film such as a gas barrier film.

[0056]

According to the method for producing a composite film of the present invention, a specific surface treatment is applied to each surface of a polyolefin-based film, and particularly, when a resin layer mainly composed of EvOH is coated off-line, A polyolefin composite in which a resin layer containing EvOH as a main component is firmly laminated without providing an adhesive layer such as a special anchor coating agent because a surface-treated substrate film excellent in handling suitability without blocking or the like can be obtained. It is possible to obtain a film efficiently.

The resulting composite film can be widely used as a gas barrier film for food packaging films and the like.

[0058]

EXAMPLES The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples. In addition, about the resin and film physical property in the following Examples and Comparative Examples, the surface treatment method, etc., it performed by the following method.

(1) Measurement of Main Peak by DSC About 5 to 6 mg of a sample was weighed, sealed in an aluminum pan, and heated from room temperature to 235 ° C. in a nitrogen flow of 20 ml / min using a differential calorimeter. Hold at this temperature for 10 minutes, then cool to room temperature at 10 ° C / min. Thereafter, a main peak was measured from a melting curve obtained at a heating rate of 10 ° C./min.

(2) Melt flow rate (MFR) Measured according to JIS K7210.

(3) Transparency (haze) Measured according to JIS K6714.

(4) Corona Discharge Treatment Surface treatment was carried out using a test machine using a corona discharge treatment base manufactured by Kasuga Electric Co., Ltd. under the following conditions. Corona discharge treatment in an air atmosphere was also performed by a similar processor.

Introduced gas: Nitrogen or nitrogen / carbon dioxide gas Oxygen concentration: 5% by volume or less Film running speed: 100 m / min Electrode: Aluminum 3-type electrode Electrode-film distance: 2.0 mm Generator: AGI-200 manufactured by Kasuga Electric Co. Roll temperature before treatment: 65 ° C Effective treatment width: 1,000 mm (5) Blocking property A piece of film of 4 cm × 30 cm is cut out and has a thickness of 3 mm.
It overlapped so that it might become. Film sample at temperature 3
After being left in an atmosphere of 0 ° C. and 70% RH for 24 hours, a pressure of 20 kg / cm ² was applied to the film sample for 30 seconds using a press machine. Thereafter, both ends of the film sample were fixed with jigs, and the bending strength was measured using a tensile tester.

[0064]

[Table 1]

(6) Unevenness of treatment In the width direction of the surface-treated surface of the substrate film, a wetting reagent is applied so as to have a width of about 20 mm and a length of about 200 mm, and a ratio of a minimum wetting width to a maximum wetting width after about 2 seconds ( (Minimum wetting width / Maximum wetting width). The evaluation place was changed and the average value of five measurements was taken. When the above ratio was less than 0.6, it was evaluated that there was processing unevenness.

(7) Surface Roughness (Ra) Using a scanning probe microscope (NanoScope IIIa) manufactured by Digital Instruments, the surface roughness was measured under the following conditions, and the center line surface roughness was determined by the average value of several times.

Mode: tapping mode AFM scanning range: 10 μm × 10 μm tip radius: 5 to 10 nm tip material: single crystal silicon scanning speed: free amplitude of 1.5 Hz cantilever; set point of 1.5 V cantilever; 1.1 Resonant frequency of ~ 1.3 V cantilever; 300 kHz (8) Oxygen barrier property Measured using an oxygen permeability measuring device (manufactured by mocon; OX-TRAN100) according to JIS K7126 B method. The measurement was performed at 27 ° C.

(9) Adhesiveness a method) Manual coating on the surface of the substrate film with a bar coater so that the coating thickness is 5 μm (when dried)
Let dry. After leaving at room temperature for one day or more, a cut having a width of about 30 mm was made in the center of the coated surface of the obtained composite film in a direction perpendicular to the flow direction of the film. From the cut on the coated surface, a length of about 50
mm cellophane adhesive tape (Nichiban Co., Ltd.)
Was adhered and pressed with a finger, and a peeling test was performed in the upper 90 ° direction. The measurement was performed 10 times while changing the measurement part, and evaluated according to Table 1.

[0069]

[Table 2]

Method b) The surface of the base film was manually coated with a bar coater to a coating thickness of 5 μm (when dried) and dried. After leaving at room temperature for one day or more, a sample having a width of 15 mm was cut out in the flow direction of the obtained composite film and subjected to a 180 ° peeling test using a tensile tester. The measurement site was changed three times or more under conditions of 20 mm between the chucks and the pulling speed of 100 m / min to obtain an average value of the peel strength.

(10) Suitability for Coating The surface-treated surface B of the substrate film was manually coated with a bar coater so as to have a coating thickness of 5 μm (when dried). The presence or absence of cissing of the coating solution immediately after coating was visually determined, and evaluated according to Table 3.

[0072]

[Table 3]

(11) Sealing strength 20 μm sealant CPP (a ternary random copolymer film having a melting point of 140 ° C., an ethylene content of 3 mol% and a butene-1 content of 1 mol%) is a resin composed mainly of EvOH as a composite film. Dry laminating on the layer side, sealant CP
Using a 5 × 200 mm heat seal bar between the P surfaces,
Heat sealed at 150 ° C. A sample having a width of 15 mm was cut out from a sample sealed under the conditions of a heat sealing pressure of 1 kg / cm ² and a heat sealing time of 1.0 second, and pulled at a pulling speed of 100 mm / min and a sample length of 40 mm (between chucks) using a tensile tester. The strength was measured and defined as the seal strength. The results were average values of five samples. (12) Antistatic Property (Surface Resistivity) The surface resistivity of the film was measured according to JIS-K6911.

Example 1 A resin containing the additives shown in Table 4 was extruded into a sheet while being heated and melted at 280 ° C. using a T-die extruder, and solidified by cooling on a chill roll. The film was longitudinally stretched by a factor of 2 and subsequently transversely stretched by a factor of 8 with a tenter transverse stretching machine. Thereafter, a corona discharge treatment is performed on one surface of the film in an air atmosphere to form a treated surface A, and then a corona discharge treatment is performed on the opposite surface in a nitrogen gas atmosphere to form a treated surface B. A surface-treated substrate film was obtained. The details of the above processing conditions are shown in Table 5.

An EvOH coating agent (manufactured by Nippon Synthetic Chemical Industry Co., Ltd .; Soarnol 20L) heated to 40 ° C. was manually coated on a corona-treated surface B of the obtained base film under a nitrogen atmosphere by a bar coater. I got

Table 6 shows the results of the various evaluations for the obtained composite film.

Example 2 A composite film was obtained in exactly the same manner as in Example 1 except that the resin containing the additives shown in Table 4 was used, and the surface treatment was performed under the conditions shown in Table 5.

Table 6 shows the results of the various evaluations for the obtained composite film.

Examples 3 and 4 Comparative Examples 1 to 5 The same as Example 1 except that the resin containing the additives shown in Table 4 was used and that the corona discharge treatment was performed under the conditions shown in Table 5. To obtain a composite film.

Table 6 shows the results of the various evaluations for the obtained composite film.

Reference Example 2 As a coating agent, 10 W of PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd .; Gohsenol NL-05, degree of saponification of 98.5% or more) was used.
A composite film was obtained in exactly the same manner as in Example 2 except that a t% aqueous solution was used.

Table 6 shows the results of the various evaluations for the obtained composite film.

[0083]

[Table 4]

[0084]

[Table 5]

[0085]

[Table 6]

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[Procedure amendment]

[Submission date] September 2, 1999 (1999.9.2)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

Further, even after the laminated, in the opposite surface on the laminated gas barrier layer EvOH like of the substrate film, winding over a few degrees of the film, the film is charged by repeating the drawer, with adhesion such as dust It also has the following problem .

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0025

[Correction method] Deleted

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Correction contents]

The average particle size of the anti-blocking agent is determined in consideration of the transparency of the film, the anti-blocking property, and the like.
It is preferably from 0.5 to 5 μm, more preferably from 1 to 3 μm .

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0066

[Correction method] Change

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(7) Surface Roughness (Ra) Using a scanning probe microscope (NanoScope IIIa) manufactured by Digital Instruments, the surface roughness was measured under the following conditions, and the center line surface roughness was determined by the average value of several times . What
In the present invention, the processing of the polyolefin base film is performed.
The surface roughness (Ra value) of the surface is in the range of 0.5 to 100 nm.
Indicates the box.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0073

[Correction method] Change

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[0073] (11) band antistatic properties (specific surface resistance) in accordance with JIS-K6911, was measured surface resistivity of the film.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name]

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Example 1 A resin containing the additives shown in Table 4 was extruded into a sheet while being heated and melted at 280 ° C. using a T-die extruder, and solidified by cooling on a chill roll. The film was longitudinally stretched by a factor of 2 and subsequently transversely stretched by a factor of 8 with a tenter transverse stretching machine. Thereafter, one surface to form a treated surface A performs corona discharge treatment under an air atmosphere of the film, followed by forming a treated surface B performs corona discharge treatment in a nitrogen gas atmosphere on the opposite side, the thickness of 20μm A surface-treated substrate film was obtained. The details of the above processing conditions are shown in Table 5.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0081

[Correction method] Change

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Reference Example 1 As a coating agent, 10 W of PVA (manufactured by Nippon Synthetic Chemical Industry; Gohsenol NL-05, saponification degree of 98.5% or more) was used.
A composite film was obtained in exactly the same manner as in Example 2 except that a t% aqueous solution was used.

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Claims (1)

[Claims] A polyolefin base film containing 0.1 to 1 part by weight of an antistatic agent has a wetting index of 35 to 4 on one surface.
A treated surface A is formed by performing a corona discharge treatment so as to have a viscosity of 5 mN / m, and a corona discharge treatment in a nitrogen and / or carbon dioxide gas atmosphere is performed on the opposite surface so as to have a wetting index of 40 to 55 mN / m. After forming the treated surface B, the treated surface B
And laminating a resin layer containing an ethylene-vinyl alcohol copolymer as a main component.