JP2000233478A - Laminated film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable superb appearance and outstanding finish with satisfactory oxygen barrier properties and good dependence upon humidity by laminating a polymeric gas barrier layer on at least one of the faces of a biaxially oriented polypropylene film with the coefficient of heat shrinkage at a specific temperature indicating a specific value or less in any direction. SOLUTION: The coefficient of heat shrinkage at 150 deg.C of a base material film in the mechanical axis direction of the film and an orthogonal direction with the former, is 5% or less respectively. A biaxially oriented polypropylene film is used and a polymeric gas barrier layer is laminated on at least one of the faces of this film. The polymeric gas barrier layer is a composite polymer layer which is formed by applying a coating solution of a composition containing a water-soluble polymer, a metallic alkoxide and/or an alkoxide silicate and polycondensating the metallic alkoxide and/or the alkoxide silicate by a sol-gel process and drying/curing the polycondensation product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel laminated film using a biaxially oriented polypropylene film (hereinafter, also referred to as an OPP film). More specifically, the present invention relates to a laminated film having excellent barrier properties (gas impermeability) to gases such as oxygen, water vapor, and nitrogen, having a good appearance, and being useful as a gas barrier film used for packaging foods and the like. is there.

[0002]

2. Description of the Related Art OPP films have excellent properties such as good workability, excellent mechanical strength, transparency, moisture-proof properties, and secondary workability such as bag-making properties. Widely used.

However, the above-mentioned OPP film has a low gas barrier property, in particular, a low barrier property against oxygen gas. When these properties are required in the above-mentioned packaging application, for example, it is used for food packaging, especially retort food packaging. In use, there was a problem in use.

[0004] Therefore, in order to provide the OPP film with a function of gas barrier properties against oxygen and the like, a polymer gas barrier layer comprising a water-soluble polymer such as a vinylidene chloride resin or a polyvinyl alcohol resin is laminated on the OPP film surface. Has been done.

Further, in order to provide a higher gas barrier property, Japanese Patent Application Laid-Open Nos.
390, JP-A-9-278968, JP-A-9-291251 and the like disclose a composition comprising an inorganic polymer obtained by polycondensing a metal alkoxide by a sol-gel method and a polyvinyl alcohol-based resin. There is disclosed a laminated film formed by laminating a polymer gas barrier layer composed of a composite polymer layer formed by condensation by thermosetting on a thermoplastic resin film.

[0006] However, the laminated film obtained by laminating the polymer gas barrier layer on the OPP film, when trying to make a bag by heat fusion, wrinkles are generated on the fusion surface, and as a packaging bag. There is a problem that the gas barrier property is reduced.

When the composite polymer layer is formed as a polymer gas barrier layer on the surface of an OPP film, the film shrinks or curls during heat treatment, and the composite polymer layer as a cured film is damaged. However, there were also problems that the gas barrier property of the varnish deteriorated and appearance defects and the like occurred.

[0008]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a laminated film obtained by laminating a polymer gas barrier layer on an OPP film, and to use the OPP film as a base material to prevent the appearance and finish from being poor. To provide a laminated film having excellent properties, which solves all the problems of a decrease in oxygen barrier property due to heat, and further, a problem of a decrease in gas barrier property as a packaging bag due to generation of wrinkles due to thermal fusion during bag making. It is in.

[0009]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object. As a result, it was found that all the above-mentioned problems could be solved by using an OPP film having a heat shrinkage rate limited to a specific range as a base material and laminating a polymer gas barrier layer on the base material,
The present invention has been completed.

That is, the present invention relates to a biaxially stretched polypropylene film having a heat shrinkage at 150 ° C. of 5% or less in both the machine axis (MD) direction and the machine direction (TD) of the film. And a polymer gas barrier layer laminated on at least one side of the film.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, an OPP film used as a base film has a structure in which polypropylene molecules are oriented by biaxial stretching. It has excellent gas barrier properties, and it is possible to exhibit a high level of comprehensive gas barrier properties by combining it with a polymer gas barrier layer laminated thereon.

An important requirement in the present invention is that the OPP film used as the base film has a thickness of 150 mm.
The heat shrinkage in the MD and TD directions (hereinafter, also simply referred to as the heat shrinkage) at 5 ° C. is 5% or less.

When the heat shrinkage is more than 5%, the degree of curl due to heat shrinkage during heating when forming a composite polymer layer described later as a polymer gas barrier layer increases, resulting in poor appearance of the resulting film, It is not preferable because the gas barrier property decreases. In addition, wrinkles are likely to occur during heat fusion, which causes a reduction in gas barrier properties of the obtained packaging bag, which is not preferable.

The heat shrinkage of the OPP film is as follows:
Considering the appearance and barrier properties of the laminated film, MD, T
D It is more preferably 4% or less in both directions, and 3% or less.
It is more preferred that:

[0015] The heat shrinkage of the OPP film in the present invention can be measured in accordance with JIS C231, as shown in Examples described later.
M at 150 ° C. according to the method described in
This is a value obtained by measuring the heat shrinkage in the D and TD directions.

Although the above cited publication discloses that a polypropylene film is used as a base film for laminating a polymer gas barrier layer, in a laminated film using an OPP film, various types of films described above are used. No mention is made of the occurrence of the issue. That is, conventionally, even the problems solved by the present invention are not known, and therefore, means for solving the problems are first proposed by the present inventors.

In the present invention, as the polypropylene resin constituting the OPP film, a known resin is used without any particular limitation. For example, propylene homopolymer, ethylene, 1-butene, 1-pentene, 1-hexene, 4-
Examples include random or block copolymers of propylene with α-olefins other than propylene such as methyl-1-pentene, and mixtures of these polymers.

In the polypropylene resin, the OP
In consideration of achieving a suitable heat shrinkage, melting point, and the like of the P film, the copolymerization ratio of α-olefins other than propylene is preferably 2 mol% or less, and preferably 1 mol%.
It is more preferred that: Further preferred polypropylene resins are propylene homopolymers.

The polypropylene resin preferably has a crystalline isotactic pentad fraction by ¹³ C-NMR of 0.950 to 0.995, and more preferably 0.970 to 0.990. It is more preferable to use a highly crystalline polypropylene resin (hereinafter, also referred to as a highly crystalline PP resin).

If the pentad fraction is less than 0.950, problems such as a decrease in the melting point of the OPP film, an increase in the heat shrinkage, and a decrease in the moisture resistance are likely to occur. On the other hand, when it is larger than 0.995, the stretchability during the production of the OPP film is reduced.

The isotactic pentad fraction is calculated as follows: Zanberi (A.Zambelli) et al by Macromolecules (Macromolecules), configuration of five propylene units which are quantified equal continuously based on the peak assignments of ^{1 3} C-NMR spectra published in 13,267 (1980) Is the fraction to take.

The above polypropylene resin can be obtained by a known production method. For example, a method of polymerizing the above-mentioned monomer using a known polymerization catalyst for polypropylene, such as TiCl ₃ , supported TiCl ₃ , or a metallocene catalyst, may be mentioned. After the polymerization, if necessary, decomposition with a peroxide or the like may be performed.

The peak-top measured value (melting point) of the polypropylene resin in DSC is preferably 155 to 165 ° C. in consideration of the heat resistance of the film, and 160 to 1 ° C.
65 ° C. is more preferred. By using a polypropylene resin having such a melting point, the above-described preferable melting point of the OPP film can be easily achieved.

Further, the temperature of the above polypropylene resin is 230 ° C.
Melt flow rate (hereinafter referred to as MFR)
Considering the extrudability and stretchability at the time of OPP film production, 1 to 10 g / 10 min is preferable, and 3 to 6 g
/ 10 min is more preferable.

In the present invention, other resins can be mixed with the polypropylene resin to such an extent that the effects of the present invention are not impaired. The resin to be mixed is not particularly limited. For example, polyolefin resins such as polyethylene and polybutene; polyolefin wax; polyolefin elastomer; hydrocarbon resins such as petroleum resins and terpene resins; ethylene and vinyl acetate, acrylic acid esters, Copolymers with acrylic acid monomers; or mixtures of two or more of these polymers.

The polypropylene resin may further contain an antistatic agent, an antifogging agent, an antiblocking agent, an antioxidant, a light stabilizer, a crystal nucleating agent, a lubricant, if necessary, as long as the effects of the present invention are not impaired. Known additives such as a surfactant for imparting lubrication and anti-blocking properties may be blended.

Other characteristics of the OPP film used in the present invention are not particularly limited as long as the OPP film has the above-mentioned heat shrinkage rate. What is excellent in mechanical properties, moisture resistance, secondary processing properties of a laminated film, etc., which are expressed depending on manufacturing conditions, may be appropriately selected and used.

For example, taking into consideration the heat resistance and moisture resistance of the film, the differential scanning calorimetry (hereinafter referred to as DS
C (hereinafter referred to as OPP)
The melting point of the film is preferably from 160 to 180 ° C, more preferably from 165 to 180 ° C.

If the melting point of the OPP film is lower than 160 ° C., the heat shrinkage increases, and the moisture resistance tends to decrease to achieve the heat shrinkage. On the other hand, when the temperature is higher than 180 ° C., the production of the OPP film tends to be difficult.

The OPP film is used for packaging,
It is particularly preferable that the film is transparent, considering that it is suitably used as a gas barrier film. Specifically, the haze value is preferably 15% or less, more preferably 10% or less.

In the present invention, the thickness of the OPP film is not particularly limited, but is preferably appropriately selected within the range of 5 to 100 μm.

The OPP film may be a single-layer film or a multilayer film. For example, a monolayer film mainly composed of propylene homopolymer, a multilayer composed mainly of a layer mainly composed of propylene homopolymer and a layer mainly composed of a random copolymer of propylene and an α-olefin other than propylene. Films and the like.

In the case of the above-mentioned multilayer film, the thickness of the layer mainly composed of propylene homopolymer is preferably at least 70% of the total layer thickness in consideration of the heat shrinkage and the like.
More preferably, it is at least 80%.

The OPP film having the heat shrinkage ratio used in the present invention is made of the above-mentioned polypropylene resin, and is biaxially stretched by a tenter sequential biaxial stretching method, a tenter simultaneous biaxial stretching method or the like as shown below. It can be suitably manufactured by appropriately selecting stretching conditions in the method and conditions for post-treatment such as thermal relaxation treatment.

For example, in the case of the tenter sequential biaxial stretching method, the stretching ratio is 3 to 5.5 times in the MD direction and 7 to 5.5 in the TD direction.
It is preferable to stretch by 11 times. Stretch ratio is MD
If it is less than 3 times in the TD direction and less than 7 times in the TD direction, the mechanical strength (tensile elasticity, etc.) of the film is undesirably reduced. Is undesirably large.

The stretching ratio in the simultaneous biaxial stretching of the tenter is preferably 4 to 8 times in both the MD and TD directions. If the stretching ratio is less than 4 times, the mechanical strength of the film is unfavorably reduced, and if it is more than 8 times, the heat shrinkage is undesirably increased.

As the stretching conditions, it is important to adopt temperature conditions that relatively suppress the orientation of the crystalline polypropylene resin. Generally, the stretching is performed at a relatively high stretching temperature. Will be

For example, the stretching temperature varies somewhat depending on the characteristics of the film-forming machine. For example, in the case of a tenter sequential biaxial stretching method, MD stretching is usually performed by roll stretching, and the heating temperature of an unstretched sheet during roll stretching is used. Is 130-160 ° C
Is preferable, and 140 to 155 ° C. is more preferable. M above
When the heating temperature of the unstretched sheet at the time of the D stretching is lower than 130 ° C., it is not preferable because the heat shrinkage rate is increased.
If the temperature is higher than 60 ° C., it is not preferable because the MD sheet sticks to the roll.

In the tenter sequential biaxial stretching method, T
D stretching is usually performed in a tenter, and the heating temperature during the tenter stretching is preferably 145 to 165 ° C,
60 ° C. is more preferred. The heating temperature during TD stretching is 1
When the temperature is lower than 45 ° C., the heat shrinkage is increased, and when it is higher than 165 ° C., whitening of the film occurs, which is not preferable.

On the other hand, in the case of simultaneous biaxial stretching of a tenter, the heating temperature during stretching is preferably from 145 to 165 ° C.
~ 160 ° C is more preferred. The heating temperature during stretching is 1
When the temperature is lower than 45 ° C., the heat shrinkage is increased, and when it is higher than 165 ° C., whitening of the film occurs, which is not preferable.

After the above stretching process, as a thermal relaxation treatment, 16
For several seconds to several tens of seconds in an ambient temperature of 0 to 180 ° C., MD
Heat treatment of about 1 to 8% in both the
It is preferable to reduce the heat shrinkage of the OPP film to a predetermined range.

When the highly crystalline PP resin is used as a film raw material, there is a case where a treatment in the MD direction is not particularly necessary as the above-mentioned heat relaxation treatment. In such a case, the above-mentioned heat relaxation treatment is performed in the TD direction. Thereby, the heat shrinkage can be achieved. Such a thermal relaxation treatment may be performed in a line after the TD stretching treatment.

In the laminated film of the present invention, the OP
Known polymer gas barrier layers to be laminated on the P film can be used without particular limitation. For example, it is composed of a water-soluble polymer layer, a water-soluble polymer, and an oxide polymer obtained by polycondensing a metal alkoxide and / or a silicon alkoxide by a sol-gel method. And a composite polymer layer obtained by condensing a polymer with a polymer.

Among them, the composite polymer layer has a superior gas barrier property as compared with a layer composed of a water-soluble polymer alone,
Since the gas barrier property has low humidity dependency and is excellent in incineration property and disposal property with respect to a chlorine-based water-soluble polymer, it can be suitably used in the present invention.

The composite polymer layer includes: (1) a mixture of a partially hydrolyzed polycondensate of at least one alkoxide selected from the group consisting of metal alkoxides and silicon alkoxides with a water-soluble polymer; A reaction product of a hydrolysis polycondensate and a water-soluble polymer or (3) a mixture of any one of the partially hydrolyzed polycondensate, a water-soluble polymer and a reaction product thereof is preferable. .

The above-mentioned water-soluble polymer is a polymer which can be completely dissolved or finely dispersed in water at room temperature, and is specifically exemplified by polyvinyl alcohol and its derivatives; carbon monoxide-ethylene copolymer. Polyalcohol obtained by reducing polyketone; carboxymethylcellulose,
Cellulose derivatives such as hydroxyethyl cellulose;
Starches such as oxidized starch, etherified starch, dextrin; polyvinylpyrrolidone, polyacrylic acid,
Examples include vinyl-based copolymers such as polymethacrylic acid, or its esters, salts, and copolymers thereof; and functional group-modified polymers of these various polymers with a carboxyl group, a silyl group, or the like.

Among these water-soluble polymers, polyvinyl alcohol-based polymers and derivatives thereof are preferable, and further, polyvinyl alcohol having a saponification degree of 75 mol% or more,
Copolymerized polyvinyl alcohols such as polyvinyl alcohol in which 40 mol% or less of all hydroxyl groups are acetalized, and ethylene-vinyl alcohol copolymer (hereinafter referred to as EvOH) in which vinyl alcohol units are 60 mol% or more are more preferable.

The degree of polymerization of the polyvinyl alcohol-based polymer and its derivative is preferably from 100 to 5,000 in view of gas barrier properties and processability, and is preferably from 500 to 5,000.
3,000 is more preferred.

On the other hand, the metal alkoxide and the silicon alkoxide used in forming the composite polymer layer are polycondensed by a sol-gel method to form an oxide polymer such as a metal oxide compound polymer or a silicon oxide compound polymer. If it is, there is no particular limitation. In particular,
Silicon alkoxides capable of forming silicon oxide such as tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, isopropyltrimethoxysilane, butyltrimethoxysilane; tetramethoxytitanium, tetraethoxytitanium, methyltrimethoxytitanium; Titanium alkoxides such as tetrabutoxytitanium, tetraisopropoxytitanium, and methyltriisopropoxytitanium that can form titanium oxide; tetramethoxyzirconium, tetraethoxyzirconium, tetrabutoxyzirconium, methyltrimethoxyzirconium, methyltriethoxyzirconium, methyltriethoxyzirconium Zirconium oxide capable of forming zirconium oxide such as methyltriisopropoxyzirconium; Aluminum alkoxides capable of forming aluminum oxide, such as toxium aluminum, triethoxy aluminum, triisopropoxy aluminum, and methyldiisopropoxy aluminum; magnesium alkoxides capable of forming magnesium oxide, such as tetramethoxy magnesium, tetraethoxy magnesium, tetra isopropoxy magnesium; Sidoxymethyltrimethoxysilane, 2-glycidoxyethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltributoxysilane,
(3,4-epoxycyclohexyl) methyltripropoxysilane, 2- (3,4-epoxycyclohexyl)
Silicon alkoxide having an epoxy group such as ethyltrimethoxysilane, 3- (3,4-epoxycyclohexyl) propyltrimethoxysilane; aminomethyltriethoxysilane, 2-aminoethyltrimethoxysilane,
1-aminoethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-aminomethylaminomethyltrimethoxysilane, N-aminomethyl-3-aminopropyltrimethoxysilane, N- ( Silicon alkoxide having an amino group such as 2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane; vinyltrimethoxysilane, vinyltriacetoxysilane, N -Β-
(N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane or a silicon alkoxide having a vinyl group such as a hydrochloride thereof; and a part of the alkoxy group of the metal alkoxide or the silicon alkoxide is replaced by a halogen atom. One or a mixture of two or more compounds can be mentioned.

Among the above metal alkoxides and silicon alkoxides, particularly preferred ones are tetramethoxysilane, tetraethoxysilane, tetramethoxytitanium, tetraethoxytitanium, tetrabutoxytitanium, tetraisopropoxytitanium, tetramethoxyzirconium, tetraethoxyzirconium , Tetrabutoxyzirconium, trimethoxyaluminum, triethoxyaluminum, triisopropoxyaluminum, glycidoxymethyltrimethoxysilane, 2-glycidoxyethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycid Xypropyl tributoxy silane.

In the present invention, the composition for forming the composite polymer layer can be obtained by appropriately selecting and mixing the water-soluble polymer and the metal alkoxide and / or silicon alkoxide. in this case,
The mixing ratio of the water-soluble polymer and the metal alkoxide and / or silicon alkoxide is determined by mixing the water-soluble polymer with the metal oxide compound polymer and / or the silicon oxide compound polymer in the composite polymer formed on the laminated film. Ratio (water-soluble polymer / metal oxide compound polymer and / or silicon oxide compound polymer w
(t% / wt%) is preferably determined in consideration of the ratio so as to be 10/90 to 80/20 in order to exhibit good gas barrier properties. The above ratio in the composite polymer is more preferably 20/80 to 70/30 in consideration of gas barrier properties and humidity dependency.

In the laminated film of the present invention, the thickness of the polymer gas barrier layer is not particularly limited, but is preferably 0.1 μm or more, particularly 0.3 μm or more in consideration of the gas barrier properties of the laminated film. In consideration of the secondary workability of the effect of the film, the thickness is preferably 10 μm or less, and particularly preferably 6 μm or less.

In the method for producing the laminated film of the present invention, the method for forming the polymer gas barrier layer is not particularly limited, and a known forming method may be employed without any limitation.

For example, as the formation of the composite polymer layer, at least one surface of the OPP film having the specific heat shrinkage is coated on at least one surface with a composition containing a water-soluble polymer and a metal alkoxide and / or a silicon alkoxide. A method of coating a liquid, polycondensing a metal alkoxide and / or a silicon alkoxide by a sol-gel method, and then drying and curing the same is generally employed.

The composition of the above-mentioned coating solution should be
There is no particular limitation as long as a polycondensate of the metal alkoxide and / or silicon alkoxide can be formed on the surface of the OPP film. For example, a composition composed of a liquid material in which a water-soluble polymer and a metal alkoxide and / or a silicon alkoxide are uniformly dissolved or dispersed in a solvent, a composition in which a hydrolyzing agent is added as necessary, and a metal After adding an alkoxide and / or a silicon alkoxide, if necessary, a hydrolyzing agent to prepare an oxide polymer that is a polycondensate in advance, and then dissolving or dispersing the compound uniformly in a solvent together with a water-soluble polymer. No.

As the hydrolyzing agent, known ones are used without any particular limitation. Specifically, inorganic acids such as hydrochloric acid,
Examples include an organic acid such as acetic acid, or an alkaline aqueous solution such as sodium hydroxide, ammonia, and an organic amine compound. However, even water alone can exert its function as a hydrolyzing agent.

As a method of coating the coating solution, a solution or solvent dispersion coating method capable of coating a thin film at a high speed is preferable in the practice of the present invention, and is suitably employed. Specific examples of these coating methods include a method of coating a coating solution on the OPP film surface with a gravure coat, a reverse coat, a spray coat, a kiss coat, a die coat, a metalling bar coat, a gravure coat in combination with a chamber doctor, and a curtain coat. It is suitable.

As a solvent for dissolving or dispersing the water-soluble polymer, water or a mixed solvent of water / lower alcohol is preferable. Among them, in consideration of adhesiveness and productivity, it is more preferable to use a water / lower alcohol mixed solvent.

The lower alcohol has a carbon number of 1 to 1.
Preferred is the alcohol of No. 3, specifically, methanol, ethanol, n-propyl alcohol, or isopropyl alcohol. The mixing ratio of water / alcohol is appropriately selected from the range of 99/1 to 20/80 by weight.

Further, in order to enhance the suitability for coating the OPP film, other water-soluble organic compounds may be added to the above-mentioned coating solution as long as the stability of the coating solution is not impaired. Specifically, in addition to the lower alcohol used as a solvent, glycols such as ethylene glycol and propylene glycol; glycol derivatives such as methyl cellosolve, ethyl cellosolve, and n-butyl cellosolve;
Polyhydric alcohols such as glycerin and wax; 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.

In the method for producing a laminated film of the present invention, a known drying method can be used without particular limitation as a method for drying the coating of the coating liquid on the OPP film.
Specifically, hot roll contact method, heat medium (air, oil, etc.)
One or more of a contact method, an infrared heating method, a microwave heating method and the like can be used.

Among these, the heating air contact method and the infrared heating method are preferable in consideration of the finish such as the film appearance and the drying efficiency.

In particular, in the drying of the composite polymer layer, it is preferable to adopt a temperature of 100 ° C. or higher in a temperature range lower than the melting point of the base film, in consideration of the expression of gas barrier properties and drying efficiency. Further, the drying temperature is more preferably 110 ° C. or higher, and particularly preferably 120 ° C.
The above is more preferred. Further, the temperature is preferably 10 ° C. or lower than the melting point of the base film, more preferably 15 ° C. or lower.

The above-mentioned drying time is preferably 5 seconds to 10 minutes in consideration of barrier properties and drying efficiency.
More preferably, the time is from 2 to 5 minutes.

Before and after the drying, if necessary,
Irradiation with high energy rays such as ultraviolet rays, X-rays, and electron beams may be performed. When a component that is polymerized by irradiation with high energy rays is blended, it is preferable to perform the irradiation with the high energy rays.

The method of forming the polymer gas barrier layer as a composite polymer layer has been described above, but the method of forming the water-soluble polymer layer can also be carried out by a known method without limitation. In general, a coating solution in which the water-soluble polymer is dissolved in the solvent is prepared, and the coating solution is coated according to the coating method.

In the present invention, the polymer gas barrier layer and O
In order to further improve the adhesion to the PP film and further improve the gas barrier properties and durability of the obtained laminated film, it is preferable to use the OPP film which has been subjected to various surface treatments.

As a preferred surface-treated OPP film,
Specifically, (a) an OPP film in which the surface of the OPP film on which the polymer gas barrier layer is laminated is subjected to a corona discharge treatment and / or a flame plasma treatment in an atmosphere of nitrogen and / or carbon dioxide;
(B) After the surface of the OPP film on which the polymer gas barrier layer is laminated is subjected to corona discharge treatment and / or flame plasma treatment in an atmosphere of nitrogen and / or carbon dioxide, it is formed on the surface. An OPP film having an anchor coat layer, and (c) at least a surface of the OPP film on which the polymer gas barrier layer is laminated is selected from the group consisting of an acid-modified polyolefin, an ethylene-containing polyolefin, and a butene-1 polyolefin. An OPP film having a layer made of one kind of polyolefin and having its surface subjected to a corona discharge treatment and / or a flame plasma treatment under an atmosphere of nitrogen and / or carbon dioxide can be mentioned.

In the OPP film of (a), O
The corona discharge treatment applied to the PP film requires that the atmosphere during the treatment be a nitrogen and / or carbon dioxide gas atmosphere, and is preferably a nitrogen atmosphere in consideration of economy.

The oxygen concentration in an atmosphere of nitrogen and / or carbon dioxide is preferably 5% by volume or less, and preferably 3% by volume or less, in consideration of the adhesion between the OPP film and the polymer gas barrier layer. Is more preferable.

The corona discharge treatment density calculated by voltage × current / (electrode width × film running speed) (W · min / m ² ) is preferably 5 to 100 W · min / m ² , and 10 to 70 W · min / m ^2. m ² is more preferred.

[0072] That is, if the processing density for OPP film surface is lower than 5W · min / m ² is not preferable because the adhesion decreases, 100W · min / m ²
If it is higher, blocking between OPP films occurs, and processing unevenness having different processing degrees in the width direction of the film occurs, which is not preferable.

The wetting index of the surface treated with the OPP film after the corona discharge treatment is preferably 40 to 55 mN / m.
5 to 50 mN / m is more preferable. Wetting index 40mN
If it is less than / m, it is not preferable because the adhesiveness is reduced, and if it is more than 55 mN / m, blocking between the OPP films occurs, and processing unevenness having different processing degrees occurs in the width direction of the film. Not preferred. The processing unevenness is not preferable because it causes a coating unevenness and an adhesive strength unevenness during coating.

On the other hand, in the OPP film of the above (a), the flame plasma treatment means that the ionized plasma in the flame generated when a combustible gas such as natural gas, LPG, propane gas or butane gas is burned by a burner or the like. This is a process of spraying on the surface of the OPP film.

In such a flame plasma treatment, the intensity of the treatment by the flame plasma is
It varies slightly depending on the PP film, but is preferably 1-1.
Appropriately selected from the range of 5 kcal / m ^{2 and 2} to 10 k
cal / m ² is more preferred.

That is, when the treatment strength is lower than 1 kcal / m ² , the adhesiveness to the polymer gas barrier layer is unfavorably reduced, and when the treatment strength is higher than 15 kcal / m ² , the OPP film is not heat-shrinkable. It is not preferable because a phenomenon (hereinafter, referred to as a piercing phenomenon) in which an end portion, which is considered to be caused by wrinkles or poor cooling, becomes thick due to heat shrinkage tends to occur.

The above processing intensity is determined by the burner output per unit time (min) and unit burner length (m) (kcal /
m), the film traveling speed (m / min), the film width (m), and the burner length (the same length as the film width) (m) used for processing the film. It is calculated by the following equation (1).

[0078]

Embedded image In the above-mentioned flame plasma processing, the distance from the front end of the inner flame of the frame to the surface of the OPP film to be processed is preferably 1 to 5 mm, more preferably 1 to 3 mm, in consideration of the stability of the processing level.

In the frame plasma treatment, a method is generally used in which a cooling roll is brought into contact with one surface of a film, and a frame plasma is sprayed on the opposite surface of the film while the film is running. The temperature of the cooling roll at that time is appropriately selected from the range of room temperature to 60 ° C.
5 ° C. is preferred.

The wetting index on the surface of the OPP film treated with the flame plasma is preferably from 35 to 65 mN / m, more preferably from 40 to 60 mN / m, and from 45 to 65 mN / m.
60 mN / m is more preferred.

If the wetting index is less than 35 mN / m, the adhesion to the polymer gas barrier layer is undesirably reduced. If it is greater than 65 mN / m, wrinkles due to thermal shrinkage of the film are generated. This is not preferable because blocking between the base films occurs.

The surface roughness (Ra) of the treated surface of the flame-plasma-treated OPP film is preferably 0.5 to 100 nm, more preferably 1 to 80 nm, and still more preferably 2 to 50 nm in consideration of the adhesiveness.

The corona discharge treatment and the flame plasma treatment may be performed independently on the surface of the OPP film, or may be carried out in combination. The order of the treatment is that the flame plasma treatment is performed last. Is preferred.

Further, the surface treatment of the OPP film used in the present invention may be used in combination with other surface treatments other than the above-mentioned treatments, as long as the effects of the present invention are not impaired. In particular,
Plasma treatment with excited inert gas, electron beam irradiation treatment,
UV irradiation treatment and the like can be mentioned.

The OPP film (b) is an OPP film obtained by laminating an anchor coat layer on the treated surface of the OPP film which has been subjected to the corona discharge treatment and / or the flame plasma treatment, and is formed thereon. A stable laminated film in which the adhesive strength of the polymer gas barrier layer is further improved can be obtained.

As the anchor coating agent used for forming the anchor coat layer, known ones can be used without particular limitation. For example, anchor coating agents such as isocyanate-based, polyurethane-based, polyester-based, polyethyleneimine-based, polybutadiene-based, polyolefin-based, and alkyl titanate-based are exemplified. Among these, in consideration of the effects of the present invention, isocyanate-based, polyurethane-based, and polyester-based anchor coating agents are preferred, and isocyanate compounds, polyurethanes and mixtures of one or more of polyurethane and urethane prepolymers and reaction products, More preferably, it is a mixture and a reaction product of one or more of polyester, polyol and polyether and isocyanate, or a solution or dispersion thereof.

The method of laminating the anchor coat layer on the treated surface of the biaxially stretched polypropylene film subjected to the flame plasma treatment is not particularly limited, but in an industrial practice, the coating solution of the anchor coat agent is gravure-coated. Coat, reverse coat, spray coat,
A method of laminating by a coating method such as a kiss coat, a die coat, a metaling bar coat, and a gravure coat combined with a chamber doctor is preferable.

[0088] Further, the amount of the anchor coat layer, preferably, be chosen from the range of 0.01-5 g / m ² by dry weight, 0.1-2 g / m ² is more preferable.

The OPP film (c) is obtained by forming an acid-modified polyolefin layer on the surface of the OPP film,
An OPP film whose surface is subjected to the corona discharge treatment and / or the flame plasma treatment, wherein the adhesive strength of the polymer gas barrier layer formed thereon is further improved;
A stable laminated film can be obtained.

As the resin constituting the acid-modified polyolefin layer, in consideration of adhesiveness and the like, the total amount of the monomer units derived from the unsaturated organic acid anhydride is 0.01 to 15% by weight, more preferably Those containing 0.1 to 10% by weight are preferred. Further, the acid-modified polyolefin resin may be used alone or a mixture of the acid-modified polyolefin resin and the polyolefin resin.

When the amount of the monomer unit derived from the above-mentioned unsaturated organic acid anhydride is less than 0.01% by weight, the adhesiveness is lowered, and when it is more than 10% by weight, the transparency is lowered. Not preferred.

The acid-modified polyolefin resin includes:
Polyolefins obtained by copolymerizing or graft-modifying the following unsaturated organic acid anhydrides or unsaturated organic acid anhydrides and derivatives thereof are preferable. Specifically, unsaturated organic acid anhydrides or unsaturated organic Acid-modified polypropylene, acid-modified polyethylene, acid-modified ethylene-propylene copolymer, modified with acid anhydride and derivatives thereof,
Acid-modified ethylene-vinyl acetate copolymer, acid-modified ethylene-butene copolymer, acid-modified propylene-butene copolymer, and the like.

Among them, acid-modified polypropylene modified with an unsaturated organic acid anhydride or an unsaturated organic acid anhydride and its derivative is preferable in consideration of transparency, heat resistance and the like.

MFR of the above acid-modified polyolefin resin
Is not particularly limited, but is appropriately selected from the range of 0.1 to 150 g / 10 min, preferably 5 to 100 g / 10 min, in consideration of migration of the polar group to the surface, workability, and the like.

Specific examples of the unsaturated organic acid anhydride include acid anhydrides such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid and citraconic acid. Further, the above acid anhydride and an acid anhydride derivative obtained from a diol, amino alcohol, diamine or the like can be used in combination. The diol, amino alcohol, diamine and the like are not particularly limited, but diols such as ethylene glycol and propylene glycol, amino ethanol,
Examples thereof include amino alcohols such as aminobutanol, and diamines such as ethylenediamine and diaminobutane.

In the acid-modified polyolefin layer used in the present invention, as the polyolefin resin to be mixed with the above-mentioned acid-modified polyolefin resin, polyolefins such as polypropylene, polyethylene and ethylene-α-olefin copolymer can be used without particular limitation. However, among these, in consideration of transparency, heat resistance, etc., the monomer unit derived from polypropylene homopolymer and ethylene is 0.1 to 1
An ethylene-propylene random copolymer containing 5 mol%,
The monomer unit derived from ethylene and 1-butene is 1 to
An ethylene-propylene-1-butene random copolymer containing 15 mol% is preferred.

The MFR of the above polyolefin resin is appropriately selected from the range of 0.1 to 20 g / 10 min, preferably 1 to 10 g / min, in consideration of extrusion processability and the like.

The thickness constituting ratio of the acid-modified polyolefin layer is not particularly limited, but is appropriately selected from the range of 1 to 50% in consideration of adhesiveness, workability, cost, and the like.
30% is preferred.

In the OPP film (c), the corona discharge treatment and / or the flame treatment performed on the acid-modified polyolefin layer may be carried out under the conditions described in detail in the laminated film (a). The treated surface after the corona discharge treatment has a wetting index of 40 to 55 mN /
m, preferably 45 to 50 mN / m.

By using the OPP film having the treated surface treated as described above and forming a polymer gas barrier layer by the above method, a laminated film of the present invention having more excellent gas barrier properties and durability can be obtained. Can be.

The laminated film of the present invention can be formed into a laminated film having various functions in addition to the effects of the present invention by further laminating an arbitrary thermoplastic resin film on the surface of the polymer gas barrier layer. it can.

In the above-mentioned laminated film, the thermoplastic resin which is the raw material resin of the thermoplastic resin film to be further laminated includes, for example, olefin resins such as polyethylene and polypropylene, polyethylene terephthalate, and the like.
Polybutylene terephthalate, polyethylene-2,6-
Polyester resin such as naphthalate, polyamide resin such as nylon 6, nylon 12, polyvinyl chloride, ethylene vinyl acetate copolymer or saponified product thereof, polystyrene, polycarbonate, polysulfone, polyphenylene oxide, polyphenylene sulfide, aromatic polyamide, polyimide , Polyamide imide, polyacrylonitrile, polyvinyl alcohol, and the like, and copolymers thereof.

Further, in addition to the gas barrier function, the laminated film of the present invention has a film surface to be a sealing surface for the purpose of preventing problems such as poor heat sealing caused by the contents adhering to the packaging material. Surface specific resistance logΩ
It is preferable to adjust the surface resistivity of the laminated film so that the value is 11 or less.

The method for adjusting the surface resistivity of the above-mentioned laminated film can be achieved by performing treatment by a known antistatic method. For example, a method of applying an antistatic agent to the surface of the laminated film, a method of blending the antistatic agent into the raw material resin of the film, and the like can be mentioned.

As the above-mentioned antistatic agent, one or more kinds of known antistatic agents may be appropriately selected in consideration of compatibility with a resin, heat stability, physical properties, environmental compatibility, low cost, and the like. It may be selected and used. Specific examples of the antistatic agent include glycerin fatty acid ester, sorbitan fatty acid ester, pentaerythritol fatty acid ester, polyethylene glycol fatty acid ester, polyglycerin fatty acid ester and other fatty acid ester-based antistatic agents, alkyldiethanolamine, alkyl Alkylamine antistatic agents such as diethanolamine fatty acid esters, alkyldiethanolamide antistatic agents composed of diethanolamine and fatty acids, cationic antistatic agents such as trialkylbenzylammonium salts and tetraalkylammonium salts, alkylbenzene sulfonates, alkyl sulfones Anionic antistatic agents such as acid salts, alkyl sulfates and alkyl phosphates, and amphoteric ions such as alkyl betaines and alkyl imidazolines Antistatic agents and the like. Among these, in consideration of antistatic properties, blocking, and the like, one or more antistatic agents of glycerin fatty acid ester, sorbitan fatty acid ester, alkyldiethanolamine, alkyldiethanolamine fatty acid ester, and alkyldiethanolamide are preferable. The number of carbon atoms in the alkyl group of the fatty acid and the alkylamine is 6 to 2 in consideration of antistatic properties and the like.
2 is preferable, and 12 to 20 is more preferable.

In the laminated film having the adjusted surface resistivity, the surface resistivity log was formed on the polymer gas barrier layer.
An embodiment in which a thermoplastic resin film having Ω of 11 or less is laminated is preferable.

Specific layer configurations include a polymer gas barrier layer / an OPP film having a surface resistivity logΩ of 11 or less, a thermoplastic resin film having a surface resistivity logΩ of 11 or less / a polymer gas barrier layer / OPP film,
Examples thereof include an OPP film having a surface specific resistance logΩ of 11 or less / a polymer gas barrier layer / a thermoplastic resin film having a surface specific resistance logΩ of 11 or less.

Further, in the above-mentioned layer constitution, in order to prevent adhesion of contents in food packaging due to static electricity and to use for bag packaging, a thermoplastic resin film having a surface specific resistance logΩ of 11 or less is a sealant film. It is preferred that

The thickness of the thermoplastic resin film having a surface resistivity logΩ of 11 or less is preferably 5 to 100 μm, more preferably 10 to 80 μm.

The application of the laminated film of the present invention is not particularly limited, but it is a film for food packaging such as a gas barrier (oxygen barrier, nitrogen barrier, carbon dioxide gas barrier, etc.) film, especially for packaging of foodstuffs in water, boil, retort sterilization packaging. It is suitable as a film for use. The packaged material is not particularly limited, but specifically, pickles, prepared dishes, boiled tsukudani, konjac, miso, kamaboko, chikuwa, processed fishery products, hamburger, wiener, sausage, ham, other processed meat products, cheese, butter , Cut rice cakes, tororo kelp, curry, stew, packed rice, and the like. Furthermore, it may be used for industrial packaging applications such as medical, electronic, chemical, and mechanical, such as agricultural chemicals, pharmaceuticals, fertilizers, and precision materials.

[0111]

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.

The properties of resins and films in the following Examples and Comparative Examples were measured by the following methods.

(1) Measurement of Main Peak by DSC of Raw Resin 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 with a differential calorimeter. Warm, hold at this temperature for 10 minutes, then cool to room temperature at 10 ° C / min. Thereafter, from the melting curve obtained at a heating rate of 10 ° C./min,
The main peak was measured.

(2) Measurement of Main Peak of Film by DSC About 5 to 6 mg of a sample was weighed, sealed in an aluminum pan, and heated at a rate of 10 ° C./min in a nitrogen flow of 20 ml / min by a differential calorimeter. To raise the temperature from room temperature to 235 ° C,
The main peak was measured from the obtained melting curve.

(3) MFR Measured according to JIS K7210.

(4) Pentad fraction (mmmm value) and copolymer composition JNM-GSX-270 ( ¹³ ) manufactured by JEOL Ltd.
C-nuclear resonance frequency (67.8 MHz) was measured under the following conditions.

Measurement mode: 1H-complete decoupling Pulse width: 7.0 microseconds (C45 degrees) Pulse repetition time: 3 seconds Integration count: 10,000 times Solvent: mixed solvent of orthocyclohexane / heavy hydrogen (90 / 10% by volume) Sample concentration: 120 mg / 2.5 ml Solvent Measurement temperature: 120 ° C. In this case, the mmmm pentad fraction was determined by measuring the splitting peak in the methyl group region of the ¹³ C-NMR spectrum. Also, the assignment of the peak in the methyl group region is A. Za
Performed according to mbelli et al [Macromolecules 13,267 (1980)].

(5) Transparency (haze) JIS K67
14 was measured.

(6) Heat Shrinkage The heat shrinkage at 150 ° C. in the MD and TD directions was measured according to JIS C2318.

(7) Oxygen barrier property JIS K7126
According to the method B, the measurement was carried out using an oxygen permeability measuring device (manufactured by mocon; OX-TRAN100). The measurement conditions were 25 ° C., 0% RH, 80% RH and 90% RH
Performed under the atmosphere of

(8) Moisture-proof (water vapor barrier) JIS
According to the K7129 B method, a moisture permeability measuring device (moc
on Corporation; PERMATRAN-WTWIN) under an atmosphere of 40 ° C. and 90% RH.

(9) Appearance of film after coating process Width 3
A 0 cm biaxially oriented polypropylene film was coated and dried and cured under the following conditions, and the film appearance was evaluated according to the following criteria. (Conditions) Drying method: Guide roll arch type hot air jet nozzle spraying method Coating method: Comma bar coater method Coating speed: 18 m / min Drying furnace length: 6 m Setting temperature: 100 to 140 ° C. Drying time: 20 seconds (Film appearance evaluation) A: Wrinkles and curls are hardly observed. ：: Some wrinkles or curls are observed. X: considerable wrinkles or curls are observed.

(10) Corona Discharge Treatment Surface treatment was carried out under the following conditions using a test machine using a corona discharge treatment machine manufactured by Kasuga Electric Co., Ltd. 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 before processing Temperature: 65 ° C Effective processing width: 1,000 mm

(11) Flame Plasma Treatment Surface treatment was performed under the following conditions using a flame plasma treatment tester manufactured by Flynn Burner (US). Fuel: natural gas (mixed air) Burner output: 328 to 853 kcal / m · min (burner width: 1 m, calorie burned per minute) Flame in the flame-distance between film surfaces: 2 mm Film running speed: 100 m / min Cooling roll temperature: 38 ° C Effective processing width: 600mm

(12) Blocking Two base films (12 × 12 cm) were superimposed on the surface treatment side and the opposite side, and under a 50 ° C., 90% RH atmosphere with a load of 10 kg applied over the entire surface. It was left for 24 hours. A sample is cut out so that an overlapped portion having a width of 30 mm and a length of 40 mm and a margin for gripping the chuck (each film is gripped by the upper and lower chucks) remain, and a tensile tester (tensile speed; 100 mm / min, distance between chucks 40)
mm), and the peeling strength was measured according to the following criteria.

(13) 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 averaging several times. Mode: tapping mode AFM Scanning range: 10 μm × 10 μm Probe radius: 5 to 10 nm Probe material: single crystal silicon Scanning speed: 1.5 Hz Cantilever free amplitude: 1.5 V Cantilever set point: 1.1 to 1. Resonant frequency of 3V cantilever: 300kHz

(14) Adhesion The coating liquid was manually coated on the surface of the biaxially stretched polypropylene film with a bar coater so that the coating layer thickness when dried was about 3 μm, and dried. After leaving at room temperature for 1 day or more, the central part of the coated surface of the obtained laminated film was subjected to the X-cut tape method (JIS K5400),
The degree of peeling was evaluated according to the following criteria. 5: No peeling of the X cut portion 4: Less than 10% of the X cut portion peeled 3: 10% or more and less than 30% of the X cut portion peeled 2: 30% or more and less than 50% of the X cut portion peeled 1 : 50% or more and less than 100% of X-cut part peeled 0: 100% of X-cut part peeled

(15) Seal Strength The sealant surfaces of the laminated film were heat-sealed at 150 ° C. using a 5 × 200 mm heat seal bar. 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 was subjected to a tensile speed of 10 using a tensile tester.
The tensile strength was measured at 0 mm / min and the sample length was 40 mm (between the chucks), and was defined as the seal strength. The results were average values of five samples.

(16) Pentad fraction (mmmm value) and copolymer composition Measured under the following conditions using JNM-GSX-270 ( ^13C- nuclear resonance frequency: 67.8 MHz) manufactured by JEOL. Measurement mode: 1H-complete decoupling Pulse width: 7.0 microseconds (C45 degrees) Pulse repetition time: 3 seconds Integration count: 10,000 times Solvent: Orthochlorobenzene / Heavy hydrogen mixture solvent (90/10% by volume) ) Sample concentration: 120 mg / 2.5 ml Solvent Measurement temperature: 120 ° C. In this case, the mmmm pentad fraction was determined by measuring the splitting peak in the methyl group region of the ¹³ C-NMR spectrum. Also, the assignment of the peak in the methyl group region is A. Za
Performed according to mbelli et al [Macromolecules 13,267 (1980)].

Example 1 Resin A shown in Table 1 was extruded into a sheet under heating and melting at 280 ° C. using a T-die extruder, cooled and solidified on a chill roll, and then heated at a sheet temperature of 151 ° C. using a hot roll stretching machine. The film is stretched longitudinally by 4.4 times, and subsequently stretched by a tenter transverse stretching machine.
After transverse stretching at 10.5 times at 58 ° C, the atmosphere temperature was 175.
While performing a heat treatment at 10 ° C. for 10 seconds, a relaxation treatment of 8% was performed in the TD direction to obtain a biaxially stretched polypropylene film. One surface of the obtained biaxially stretched polypropylene film was subjected to a corona treatment. Table 2 shows the evaluation results of the obtained biaxially stretched films. Next, 30 parts by weight of tetraethoxysilane, 20 parts by weight of ethanol, 1 part by weight of 2N hydrochloric acid and 4 parts by weight of water were mixed and stirred at room temperature for 1 hour. Then, 3 parts by weight of γ-glycidoxytrimethoxysilane, soarnol 2
40 L of 0 L (ethylene-vinyl alcohol water / IPA solution manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and 0.15 part by weight of N, N-dimethylbenzylamine were added and stirred to obtain a coating liquid A. The coating liquid A was coated on the corona-treated surface of the biaxially stretched polypropylene film by a bar coater so that the coating layer thickness after drying was 3 μm, and dried and cured under the conditions shown in Table 3. Table 3 shows the evaluation results of the obtained laminated films.

Examples 2 and 3 and Comparative Examples 1 and 2 The same operation as in Example 1 was carried out except that the biaxially oriented polypropylene films shown in Table 2 were used and dried and cured under the conditions shown in Table 3. Then, a laminated film was obtained. Table 3 shows the evaluation results.

Comparative Example 3 A laminated film was obtained in the same manner as in Example 1, except that 20 L of Soarnol alone was used as a coating agent. Table 3 shows the evaluation results.

[0133]

[Table 1]

[0134]

[Table 2]

[0135]

[Table 3]

Example 4 A resin A shown in Table 1 was extruded into a sheet under heating and melting at 280 ° C. using a T-die extruder, cooled and solidified on a chill roll, and then heated at a sheet temperature of 148 ° C. using a hot roll stretching machine. The film is stretched longitudinally by 4.4 times, and subsequently stretched by a tenter transverse stretching machine.
After transversely stretching 9.5 times at 63 ° C., the ambient temperature is 168 ° C.
8% relaxation treatment in the TD direction while heat-treating for 10 seconds at, to obtain a biaxially stretched polypropylene film. Thereafter, one side of the film was subjected to a frame plasma treatment (treatment intensity: 6.8 kcal / m ² ) to obtain a 20 μm surface-treated base film. Table 4 shows the results of the evaluation of the obtained surface-treated substrate film. Next, the coating liquid A obtained in Example 1 was coated on a surface-treated surface of the obtained surface-treated base film with a bar coater so that the coating layer thickness after drying was 3 μm, and the coating liquid A was heated at 120 ° C. for 2 minutes. Dry cured. Table 5 shows the evaluation results of the obtained laminated films.

Examples 5 and 6 A laminated film was obtained in the same manner as in Example 1 except that the surface-treated base films shown in Table 4 were used. Table 5 shows the evaluation results.

Example 7 An anchor coating agent (TM329 / CAT-8B manufactured by Toyo Morton Co., Ltd., 100 parts by weight / 1 part) was applied to the surface of the composite polymer layer of the laminated film obtained in Example 4 using a bar coater.
00 parts by weight with an ethyl acetate solvent to adjust the nonvolatile content to 10% by weight) to a dry weight of 2 g / m ² and then dried at 80 ° C. Further, a 40 μm unstretched LLDPE film was dry-laminated on the anchor coat layer to obtain a laminated film.
Table 5 shows the evaluation results.

Example 8 Instead of a 40 μm unstretched LLDPE film, 25
Same as Example 7 except that a μm sealant CPP (propylene-ethylene-1-butene ternary random copolymer film having a melting point of 140 ° C., an ethylene content of 3 mol% and a 1-butene content of 1 mol%) was used. To obtain a laminated film. Table 5 shows the evaluation results.

Example 9 A laminated film was obtained in the same manner as in Example 7 except that the surface-treated substrate films shown in Table 4 were used. Table 5 shows the evaluation results.

Example 10 A laminated film was obtained in the same manner as in Example 8, except that the surface-treated base film shown in Table 4 was used. Table 5 shows the evaluation results.

[0142]

[Table 4]

[0143]

[Table 5]

Example 11 Resin A shown in Table 1 was extruded into a sheet while being heated and melted at 280 ° C. using a T-die extruder, cooled and solidified on a chill roll, and then 4.4 times with a hot roll stretching machine. Stretch longitudinally,
Subsequently, the film was transversely stretched 9.5 times by a tenter transverse stretching machine, and then heat-treated at an ambient temperature of 168 ° C. for 10 seconds.
An 8% relaxation treatment was performed in the D direction to obtain a biaxially stretched polypropylene film. Thereafter, one side of the film was subjected to a frame plasma treatment (treatment intensity: 6.8 kcal / m ² ) to obtain a 20 μm surface-treated base film. Then
An anchor coating agent (TM329 / CAT-8 manufactured by Toyo Morton Co., Ltd.) is applied to the surface-treated surface of the obtained surface-treated substrate film.
B 100 parts by weight / 100 parts by weight was adjusted with an ethyl acetate solvent so that the nonvolatile content became 10% by weight), manually coated with a bar coater, dried at 100 ° C. for 5 minutes, and left at room temperature for one day or more. Then, a laminated film was obtained. The dry weight of the anchor coat layer was 2 g / m ² . The coating liquid A obtained in Example 1 was coated with a bar coater so that the coating layer after drying had a thickness of 3 μm, and dried and cured at 120 ° C. for 2 minutes. Table 6 shows the evaluation results of the obtained laminated films.

Examples 12 and 13 A laminated film was obtained in the same manner as in Example 11 except that the surface-treated base films shown in Table 4 were used. Table 6 shows the evaluation results.

Example 14 As an anchor coating agent, AD335 manufactured by Toyo Morton Co., Ltd.
A / CAT-10 100 parts by weight / 6 parts by weight
A laminated film was obtained in the same manner as in Example 11, except that a mixed solvent of / toluene 1 part by weight / 1 part by weight was used to adjust the nonvolatile content to 10% by weight. Table 6 shows the evaluation results.

Examples 15 and 16 A laminated film was obtained in the same manner as in Example 11 except that the surface-treated base films shown in Table 4 were used. Table 6 shows the evaluation results.

Example 17 A test coater 3 manufactured by Inoue Metal Industry Co., Ltd. was applied to the surface-treated surface of the surface-treated substrate film obtained in the same manner as in Example 11.
No. unit and an anchor coating agent (TM manufactured by Toyo Morton Co., Ltd.)
329 / CAT-8B 100 parts by weight / 100 parts by weight with an ethyl acetate solvent to adjust the non-volatile content to 10% by weight) to form a dry weight of 1 g / m ² . Next, the coating liquid A obtained in Example 1 was gravure coated so that the thickness of the coating layer after drying was 3 μm. Further, the anchor coating agent was dried at a dry weight of 2 g /
m ^2, and a 40 μm non-stretched L
The LDPE film was dry-laminated to obtain a laminated film. Table 6 shows the evaluation results.

Example 18 Instead of a 40 μm unstretched LLDPE film, 20
Same as Example 17 except that a μm sealant CPP (propylene-ethylene-1-butene ternary random copolymer film having a melting point of 140 ° C., an ethylene content of 3 mol% and a 1-butene content of 1 mol%) is used. To obtain a laminated film. Table 6 shows the evaluation results.

Example 19 A laminated film was obtained in the same manner as in Example 17 except that the surface-treated base films shown in Table 4 were used. Table 6 shows the evaluation results.

Example 20 A laminated film was obtained in the same manner as in Example 18 except that the surface-treated substrate films shown in Table 4 were used. Table 6 shows the evaluation results.

Example 21 A test coater 3 manufactured by Inoue Metal Industry Co., Ltd. was applied to the surface-treated surface of the surface-treated base film obtained in the same manner as in Example 11.
No. unit and an anchor coating agent (AD manufactured by Toyo Morton Co., Ltd.)
335A / CAT-10 100 parts by weight / 6 parts by weight
With a mixed solvent of MEK / toluene 1 part by weight / 1 part by weight,
(Adjusted to have a nonvolatile content of 10% by weight) was laminated so as to have a dry weight of 1 g / m ² . Next, the coating liquid A obtained in Example 1 was coated with a dried coating layer having a thickness of 3 μm.
It was gravure coated. Further, an anchor coat agent (TM329 / CAT-8B10 manufactured by Toyo Morton Co., Ltd.)
0 parts by weight / 100 parts by weight with an ethyl acetate solvent to adjust the nonvolatile content to 10% by weight).
m ^2, and a 40 μm non-stretched L
The LDPE film was dry-laminated to obtain a laminated film. The results are shown in Table 6.

Example 22 Instead of a 40 μm unstretched LLDPE film, 20
Same as Example 21 except that a μm sealant CPP (propylene-ethylene-1-butene ternary random copolymer film having a melting point of 140 ° C., an ethylene content of 3 mol% and a 1-butene content of 1 mol%) was used. To obtain a laminated film. The results are shown in Table 6.

Example 23 A laminated film was obtained and evaluated in the same manner as in Example 21 except that the surface-treated base films shown in Table 4 were used. The results are shown in Table 6.

Example 24 A laminated film was obtained and evaluated in the same manner as in Example 22, except that the surface-treated base films shown in Table 4 were used. The results are shown in Table 6.

[0156]

[Table 6]

Example 25 A resin A shown in Table 1 was extruded into a sheet while being heated and melted at 280 ° C. using a T-die extruder, cooled and solidified on a chill roll, and then 4.4 times with a heated roll stretching machine. Stretch longitudinally,
A uniaxially stretched sheet was obtained. As the acid-modified polyolefin layer, a mixed resin of resin D shown in Table 1 and Umex 1001 (maleic anhydride-modified polypropylene manufactured by Sanyo Chemical Industries, Ltd .: monomer unit 0.5 wt% derived from unsaturated organic acid anhydride) ( D / UMEX 1001 = 80/20 (w
t% / wt%)) is extruded into a sheet under heating and melting at 230 ° C. by a T-die extruder, and is laminated on the chill roll to the uniaxially stretched sheet to obtain a two-layer sheet, and then laterally stretched by a tenter. After stretching 9.5 times in a horizontal direction by a machine, heat-treat at 168 ° C. for 10 seconds,
% Relaxation treatment to obtain a biaxially oriented polypropylene film. Thereafter, a flame plasma treatment (treatment intensity: 6.5 kcal / m ² ) is applied to the surface of the acid-modified polyolefin layer.
Was performed to obtain a 20 μm surface-treated base film i shown in Table 7. Example 1 was applied to the surface-treated surface of the obtained film.
The coating solution A obtained in the above was coated with a bar coater so that the thickness of the coating layer after drying was 3 μm.
After drying for a minute, a laminated film was obtained. Table 8 shows various evaluation results.

Examples 26 to 28 Laminated films were obtained in the same manner as in Example 25, except that the resins shown in Table 1 and the surface-treated base films shown in Table 7 were used. Table 8 shows the evaluation results.

Example 29 Resin A shown in Table 1 was prepared at 280 ° C. using a T-die extruder.
After being extruded into a sheet under heating and melting, and solidified by cooling on a chill roll, it was longitudinally stretched 4.4 times by a heating roll stretching machine to obtain a uniaxially stretched sheet. Resin D and Tuffmer X shown in Table 1
Mixed resin with R110T (Mitsui Chemicals propylene-butene-1 copolymer) (D / XR110T = 80/20)
(Wt% / wt%)) at 230 ° C using a T-die extruder.
After extruding into a sheet under heat and melting, the sheet is laminated on the chill roll to the uniaxially stretched sheet to obtain a two-layer sheet, and subsequently transversely stretched 9.5 times by a tenter transverse stretching machine. While heat-treating for 10 seconds, a relaxation treatment of 8% was performed in the TD direction to obtain a biaxially stretched polypropylene film. Thereafter, one surface of the film is subjected to a corona discharge treatment (treatment density: 48 w · min / m ² ) under a nitrogen atmosphere, and further, a flame plasma treatment (treatment intensity: 6 kca).
1 / m ² ) to obtain a 20 μm surface-treated substrate film 1 shown in Table 7. On the surface-treated surface of the obtained film, the coating liquid A obtained in Example 1 was coated with a bar coater so that the coating layer thickness after drying was 3 μm,
After drying at 120 ° C. for 2 minutes, a laminated film was obtained. Table 8 shows various evaluation results.

Example 30 Resin B shown in Table 1, Resin D shown in Table 1, and Eumex 1
010 (monomer unit derived from maleic anhydride-modified polypropylene / unsaturated organic acid anhydride manufactured by Sanyo Chemical Industries, Ltd.
0% by weight) (D / UMEX 1010 =
80/20 (wt% / wt%)) using a multi-layer T-die extruder, extruding the sheet at 280 ° C. while heating and melting, cooling and solidifying on a chill roll, and then extruding 5
After stretching longitudinally by 9.5 times and then transversely stretching by 9.5 times with a tenter transverse stretching machine, a biaxially stretched polypropylene film is subjected to an 8% relaxation treatment in the TD direction while performing a heat treatment at an ambient temperature of 168 ° C. for 10 seconds. I got Thereafter, one surface of the film was subjected to corona discharge treatment under a nitrogen atmosphere (treatment density: 50 w ·
min / m ² ) to obtain a 20 μm surface-treated base film m shown in Table 7. On the surface-treated surface of the obtained film, the coating liquid A obtained in Example 1 was coated with a bar coater so that the thickness of the coated layer after drying was 3 μm, and dried at 120 ° C. for 2 minutes, and laminated. A film was obtained. Table 8 shows various evaluation results.

Example 31 The coating solution obtained in Example 1 was applied to the surface-treated surface of the surface-treated substrate film m obtained in the same manner as in Example 30, using a No. 3 test coater manufactured by Inoue Metal Industry Co., Ltd. A was gravure coated so that the thickness of the dried coat layer was 3 μm. Further, the anchor coat agent was dried with a dry weight (TM329 / CAT-8B manufactured by Toyo Morton Co., Ltd. 100 parts by weight / 10 parts by weight).
0 parts by weight, adjusted with an ethyl acetate solvent so that the nonvolatile content becomes 10% by weight) to 2 g / m ² .
A 40 μm unstretched LLDPE film was dry-laminated thereon to obtain a laminated film. Table 8 shows the evaluation results.

Example 32 Instead of a 40 μm unstretched LLDPE film, 25
Using a sealant CPP of μm (a propylene-ethylene-1-butene ternary random copolymer film having a melting point of 140 ° C., an ethylene content of 3 mol% and a 1-butene content of 1 mol%) in the same manner as in Example 25 A laminated film was obtained in the same manner as in Example 31, except that the obtained surface-treated substrate film i was used. Table 8 shows the evaluation results.

[0163]

[Table 7]

[0164]

[Table 8]

Example 33 Anchor coating agent (TM329 / CAT-8B manufactured by Toyo Morton Co., Ltd., 100 parts by weight / 1 part) was applied to the surface-treated surface of the biaxially stretched polypropylene film (X layer) shown in Tables 9 and 10.
00 parts by weight, adjusted to a nonvolatile content of 10% by weight with an ethyl acetate solvent) using a bar coater so as to have a dry weight of 2 g / m ² and dried at 90 ° C. for 5 minutes. The coating solution A obtained in Example 1 was coated on the anchor coat surface with a bar coater,
For 5 minutes (Y layer). On the cured surface, the thermoplastic resin films (Z layers) shown in Tables 9 and 11 were dry-laminated using the same anchor coating agent as above to obtain a laminated film. Table 12 shows the evaluation results of the obtained laminated films.

Example 34 A laminated film was obtained in the same manner as in Example 33, except that the biaxially stretched polypropylene film and the thermoplastic resin film shown in Tables 9 to 11 were used. Table 12 shows the evaluation results.

Comparative Example 4 A laminated film was obtained in the same manner as in Example 33, except that 20 L of Soarnol alone was used as the coating agent. Table 11 shows the evaluation results.

Comparative Example 5 Montmorillonite (Kunimine F, manufactured by Kunimine Industries Co., Ltd.) was ultrasonically dispersed in ion-exchanged water so as to have a concentration of 1 wt% (Solution B). Polyvinyl alcohol (Gohsenol NL05 manufactured by Nippon Synthetic Chemical Co., Ltd.) was heated and dissolved in ion-exchanged water so as to have a concentration of 1 wt% (solution C). Equal amounts of the liquid B and the liquid C were mixed to obtain a coating liquid. Except for using the above coating liquid, the same operation as in Example 33 was performed to obtain a laminated film. Table 11 shows the evaluation results.

[0169]

[Table 9]

[0170]

[Table 10]

[0171]

[Table 11]

[0172]

[Table 12]

As described above, the laminated film of the present invention exhibits excellent oxygen barrier properties and high humidity resistance under high humidity.
On the other hand, when only the water-soluble polymer was used as in Comparative Example 4, and when the resin containing the layered inorganic compound was used as in Comparative Example 5, the oxygen barrier property under sufficiently high humidity was not obtained. It cannot have moisture-proof properties.

Example 35 Myristic acid diethanolamide as antistatic agent
Polypropylene containing 5% by weight (MFR; 4 g / 10 m)
in, melting point; 165 ° C., pentad fraction; 0.980)
Is heated and melted at 280 ° C. using a T-die extruder and extruded into a sheet under cooling and solidification on a chill roll, then longitudinally stretched 4.4 times by a heating roll stretching machine, and subsequently by a tenter transverse stretching machine. After 9.5 times transverse stretching, 8% in the TD direction while performing a heat treatment at an ambient temperature of 168 ° C. for 10 seconds.
Was performed to obtain a biaxially stretched polypropylene film. Thereafter, one surface of the film was subjected to a corona discharge treatment (treatment density: 50 w · min / m ² ) in a nitrogen atmosphere, and a heat shrinkage MD / TD: 3.2% / 4.2%, a wetting index: 4
A surface-treated base film of 8 mN / m and 20 μm was obtained.
After coating the treated surface of the surface-treated base film with an anchor coat agent (manufactured by Toyo Morton Co., Ltd .; 100 parts by weight of main agent AD335AE / 10 parts by weight of curing agent CAT-10) so that the dry film thickness becomes 1 μm using a bar coater. Example 1
Was applied with a bar coater so that the coating layer thickness after drying was 3 μm. After further performing the same anchor coat treatment as above on the coated surface,
Myristic acid diethanolamide as antistatic agent
Random polypropylene containing 3% by weight (MFR; 7 g)
/ 10 min, melting point: 140 ° C., ethylene content 2 wt
%) As a raw material, and a 50 μm double-sided corona treatment (wetting index: 40 mN / m (strong treatment) and 37 mN / m (weak treatment)) unstretched polypropylene film was dry-laminated to obtain a laminated film. Table 13 shows the evaluation results. In addition, a package was prepared by placing the above-mentioned laminated film such that the unstretched polypropylene film side was on the inside, and a shaved node was inserted, but there was no adhesion to the interior surface.

[0175]

[Table 13]

[0176]

The laminated film of the present invention is obtained by polycondensing a specific composition on at least one surface of a specific biaxially oriented polypropylene film as a base film by a sol-gel method. By laminating composite polymer layers, not only the oxygen barrier property and the humidity dependency of the oxygen barrier property are good, but also the appearance and finish after coating and heat sealing after sealant lamination are excellent. Film. Therefore, the laminated film of the present invention is not only suitable as a gas barrier film, but also widely useful as a food packaging film.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C08J 7/00 303 C08J 7/00 303 7/04 CES 7/04 CESP C08K 5/05 C08K 5/05 C08L 23/12 C08L 23/12 29/04 29/04 A

Claims (2)

[Claims] 1. A biaxially oriented polypropylene film having a heat shrinkage at 150 ° C. of 5% or less in both a machine axis direction of the film and a direction perpendicular to the machine axis direction;
A laminated film comprising a polymer gas barrier layer laminated on at least one surface of the film. 2. A polymer gas barrier layer comprising: (1) a mixture of a partially hydrolyzed polycondensate of at least one alkoxide selected from the group consisting of metal alkoxides and silicon alkoxides with a water-soluble polymer; The reaction product of the partially hydrolyzed polycondensate and the water-soluble polymer, or (3) a mixture of the partially hydrolyzed polycondensate, the water-soluble polymer and the reaction product. 2. The laminated film according to 1.