JP2004168040A - Metal vapor deposited biaxially stretched polypropylene film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal vapor deposited biaxially stretched polypropylene film, which is excellent in gas barrier performance and can maintain the gas barrier performance after fabrication, by using a biaxially stretched polypropylene film produced by a common length-width successive biaxial drawing process. <P>SOLUTION: The metal vapor deposited biaxially stretched polypropylene film is obtained by laying a metal vapor deposited layer on at least one side of a substrate make of the biaxially stretched polypropylene film; wherein the film comprises, a polypropylene whose melting strain (MS) and melt flow rate (MFR) measured at 230°C are in a relation fulfilling formula (1), log(MS)>-0.61log(MFR)+0.82, and/or a polypropylene whose melting strain (MS) and melt flow rate (MFR) measured at 230°C are in a relation fulfilling formula (2), log(MS)>-0.61log(MFR)+0.52 and to whcih one or more additives compatible with the polypropylene and able to provide plasticizing effect while drawing are added. <P>COPYRIGHT: (C)2004,JPO

Description

  The present invention relates to a metal-deposited biaxially oriented polypropylene film suitable for a wide range of uses such as packaging and industrial uses.

  Polypropylene films have been widely used as packaging films because of their excellent moisture resistance, strength, transparency, and surface gloss. Further, a polypropylene film coated with polyvinylidene chloride has been widely used as a transparent film having excellent gas barrier properties for the purpose of enhancing gas barrier properties and moisture proof properties of the film. However, polyvinylidene chloride has been pointed out to have an adverse effect on the environment due to the generation of chlorine-based gas and toxic chlorine-based substances during incineration. In recent years, there has been a movement to convert all gas barrier packaging materials to polyolefin resins for the purpose of cost reduction and recovery and reuse of the gas barrier packaging materials. Therefore, metal such as aluminum is widely deposited (metallized) for the purpose of improving the appearance of the display due to the metallic luster, improving the gas barrier performance, and suppressing the deterioration of the contents due to external light such as ultraviolet rays. ing.

  Regarding the metal-deposited film, in order to improve the gas barrier performance by providing a coating layer between the base film and the metal-deposited layer, the surface of the coating has a carboxylic acid concentration of 0.005 or more thermoplastic resin film for packaging and A metallized thermoplastic film for packaging having a metal layer provided on a coating film (see Patent Document 1), a mixed solution of a metal alkoxide and an isocyanate compound is applied on a base layer, and an evaporation layer made of an inorganic compound is provided on a coating layer dried. Gas barrier laminate (see Patent Document 2), a gas barrier material having a vapor-deposited layer in which a metal alkoxide or hydrolyzate coating layer is provided on a metal surface of a vapor-deposited film in which a vapor-deposited layer made of an inorganic compound is provided on a base layer ( Many studies have been made so far, such as Patent Document 3). However, when a polypropylene film is applied to the base layer, the adhesive strength between the base layer and the coating layer and the vapor deposition layer is low, and when processing into a packaging bag or the like that requires gas barrier properties, the coating layer and the vapor deposition layer are likely to peel off. Gas barrier performance may deteriorate. In addition, there is a problem in that the vapor deposition layer of the vapor deposition film is damaged during the process when the coating layer is installed offline, resulting in poor appearance or deterioration of gas barrier performance. In order to solve this problem, biaxial stretching for metal vapor deposition provided a coating layer made of a polyester urethane resin and a water-soluble organic solvent so as to have a specific thickness and a specific adhesive strength on at least one surface of a polypropylene base layer. A polypropylene film is disclosed (see Patent Document 4).

  Also, due to social demands for reduction of waste and resources, there is a growing expectation for thinner materials, especially for packaging applications. At present, for packaging, for example, a 20 μm biaxially stretched polypropylene film or the like is used, and most of them are manufactured by a general-purpose longitudinal-lateral sequential biaxial stretching method. The general-purpose vertical-horizontal sequential biaxial stretching method referred to here is an undrawn method in which a polymer is melted by an extruder, passed through a filter, extruded from a slit die, wound around a metal drum, and cooled and solidified into a sheet. A film is obtained, the unstretched film is stretched in the longitudinal direction between rolls provided with a difference in peripheral speed, then guided to a tenter, stretched in the width direction, heat-fixed, and cooled to obtain a rolled stretched film. This is a typical method for producing a stretched polypropylene film.

  If the same performance and processing suitability can be obtained with a biaxially stretched polypropylene film of 15 μm as compared to the biaxially stretched polypropylene film of 20 μm exemplified here, dust and resources are reduced by 25%.

  In order to satisfy such a demand, it is necessary to first strengthen the biaxially oriented polypropylene film to suppress the elongation against the tension in the processing step. At this time, since the tension in the processing step is applied in the longitudinal direction of the film, it is necessary to strengthen the biaxially oriented polypropylene film mainly in the longitudinal direction.

  In general, when the polypropylene film is strengthened, the heat shrinkage of the polypropylene film tends to increase. When the dimensional stability of the film at high temperature is deteriorated, the film shrinks during secondary processing such as printing, coating, and laminating, and the commercial value of the film may be extremely reduced. Therefore, it is necessary to suppress the heat shrinkage to approximately the same as or less than a general-purpose biaxially stretched polypropylene film.

In order to strengthen a biaxially stretched polypropylene film, a method of stretching the film in the longitudinal direction and the width direction and then stretching it again in the longitudinal direction to form a film strong in the longitudinal direction is known (for example, Patent Document 5). To 7). Furthermore, in order to eliminate the weakness in the width direction of a film strong in the longitudinal direction, a method is disclosed in which a polypropylene sheet having a specific melt crystallization temperature is biaxially stretched and then re-stretched in the longitudinal direction. Reference 8).
JP-A-7-314612 JP-A-7-266484 JP-A-8-267637 JP 2000-108262 A Japanese Patent Publication No. 41-21790 JP-B-49-18628 JP-A-56-51329

  However, when a polypropylene film is applied to the base layer of the vapor-deposited film, it is not sufficient to merely suppress the separation of the base layer from the coating layer or the vapor-deposited layer. That is, since the longitudinal rigidity of the polypropylene film serving as the base layer is low, film cracks occur in the deposited film during secondary processing such as printing, coating, laminating, and bag making, and gas barrier performance is deteriorated. There was a problem.

  In addition, it is difficult to obtain a biaxially oriented polypropylene film that has been strengthened in the longitudinal direction by a general-purpose longitudinal-lateral sequential biaxial stretching method. That is, in the general-purpose longitudinal-horizontal sequential biaxial stretching method, the temperature needs to be in a semi-molten state in order to transversely stretch the oriented crystal generated by the longitudinal stretching. For this reason, after the transverse stretching, most of the crystals rearranged in the width direction, and the obtained biaxially stretched polypropylene film had rigidity biased in the width direction.

  Furthermore, the above-described method of re-stretching in the longitudinal direction has a problem that the process is complicated and not only increases the equipment cost, but also that the heat shrinkage mainly in the longitudinal direction is higher than that of a general-purpose biaxially stretched polypropylene film. there were.

  The object of the present invention is to solve the above problems, while improving the adhesion between the metal deposited film and the substrate when metal is deposited, the longitudinal direction of the biaxially oriented polypropylene film serving as the base layer. It is an object of the present invention to provide a metal-deposited biaxially stretched polypropylene film having excellent gas barrier performance, which suppresses deterioration of gas barrier performance after secondary processing by increasing rigidity. In addition, the thermal dimensional stability of the biaxially oriented polypropylene film serving as the base layer, the moisture resistance, and the like, the so-called general-purpose biaxially oriented polypropylene formed by using the general-purpose vertical-horizontal sequential biaxial stretching method using a general-purpose polypropylene. An object of the present invention is to provide a metal-deposited biaxially-stretched polypropylene film which has almost the same performance even when the base layer is made thinner as compared with a conventional metal-deposited biaxially-stretched polypropylene film by being substantially equal to or superior to the film.

  Means for Solving the Problems As a result of intensive studies, the present inventors have found that the above-described object can be achieved by the following configuration.

That is, in the present invention, the relationship between the melt tension (MS) and the melt flow rate (MFR) measured at 230 ° C. is expressed by the following equation (1).
log (MS)>-0.61 log (MFR) +0.82 (1)
Containing a polypropylene that satisfies, and compatible with the polypropylene, at least one surface of a base layer made of a biaxially stretched polypropylene film in which one or more additives capable of having a plasticizing effect at the time of stretching are mixed, a metal deposition layer is provided. A metal-deposited biaxially stretched polypropylene film, which is installed.
As another configuration, the relationship between the melt tension (MS) and the melt flow rate (MFR) measured at 230 ° C. is expressed by the following equation (2).
log (MS)>-0.61 log (MFR) +0.52 (2)
A metal vapor-deposited layer is provided on at least one surface of a base layer made of a biaxially stretched polypropylene film in which at least one kind of additive that is compatible with polypropylene and has a plasticizing effect at the time of stretching is mixed. A biaxially oriented polypropylene film.
Furthermore, as a preferred embodiment, the adhesion strength of the metal vapor-deposited layer of the above-mentioned vapor-deposited film is 0.3 N / cm or more, and the thickness between the base layer and the metal vapor-deposited layer is 0.05 to 2 μm. That the metal layer of the vapor-deposited film provided with the above-mentioned coating layer has an adhesion strength of 0.6 N / cm or more, and that the additive does not substantially contain a polar group. A terpene resin containing substantially no resin and / or polar group; a mesopentad fraction (mmmm) of polypropylene of 90 to 99.5%; and an overcoat layer provided on the metal deposition layer. A metal-deposited biaxially stretched polypropylene film, characterized in that:
It is.

  As described below, the metal-deposited biaxially stretched polypropylene film of the present invention has a base layer in the longitudinal direction without deteriorating important properties such as dimensional stability and moisture resistance as compared with the conventional biaxially stretched polypropylene film. By using a biaxially oriented polypropylene film with increased rigidity, it exhibits excellent tensile strength against processing tension during film processing such as printing, laminating, coating, and bag making, and deteriorates gas barrier properties due to the occurrence of film cracks. Can be suppressed. In addition, compared to a conventional vapor-deposited film using a general-purpose biaxially oriented polypropylene film as a base layer, the rigidity in the longitudinal direction is high even at the same thickness, and since it has excellent gas barrier properties, the base layer is higher than that of a conventional metal-deposited biaxially oriented polypropylene film. Processing characteristics and gas barrier performance can be maintained even when the film is made thin.

  In addition, as described below, the metal-deposited biaxially stretched polypropylene film of the present invention can be used in the form of a composite formed with another film to be processed into a structural member. Can be improved. Furthermore, even if the film of the present invention or another film to be combined with the film of the present invention is appropriately thinned, the secondary workability as a component, gas barrier performance, and the like can be maintained, so that waste and resources are reduced. Can be reduced.

The biaxially oriented polypropylene film used for the base layer of the present invention has a melt tension (MS) and a melt flow rate (MFR) measured at 230 ° C. of the following formula (1).
log (MS)>-0.61 log (MFR) +0.82 (1)
Including high melt tension polypropylene. Such a polypropylene is generally referred to as a high melt strength polypropylene (High Melt Strength-PP; hereinafter, referred to as HMS-PP) having a high MS.

  Here, the MS measured at 230 ° C. means that the polypropylene is heated to 230 ° C. using a melt tension tester manufactured by Toyo Seiki Co., Ltd., and the molten polypropylene is discharged at an extrusion speed of 15 mm / min to form a strand. The tension at the time of drawing at a speed of 0.5 m / min was measured, and was defined as MS (unit: cN).

  The MFR measured at 230 ° C. is measured under a load of 2.16 kg according to JIS Z 7210 (2002) condition M (unit: g / 10 minutes).

  The polypropylene used for the biaxially stretched polypropylene film used for the base layer of the present invention contains polypropylene satisfying the formula (1), so that the rigidity in the longitudinal direction, which has been difficult in the general-purpose vertical-horizontal sequential biaxial stretching method, has been difficult. High biaxially oriented polypropylene film can be produced. That is, the polypropylene that satisfies the formula (1) suppresses rearrangement of the vertically-oriented crystals in the width direction during the transverse stretching.

  As a method for obtaining a polypropylene satisfying the formula (1), a method of blending a polypropylene containing a high molecular weight component, a method of blending an oligomer or a polymer having a branched structure, and a method described in JP-A-62-121704 are described. A method of introducing a long-chain branched structure into a polypropylene molecule or, as described in Japanese Patent No. 2869606, a melt tension, an intrinsic viscosity, a crystallization temperature and a melting point are respectively specified without introducing a long-chain branch And a method of using a linear crystalline polypropylene having a boiling xylene extraction residual ratio within a specific range is preferably used.

  For the biaxially stretched polypropylene film used for the base layer of the present invention, it is particularly preferable to use HMS-PP in which a long chain branch is introduced into the polypropylene molecule to increase the melt tension. Specific examples of the HMS-PP in which the melt tension is increased by introducing a long chain branch include HMS-PP manufactured by Basell (type name: PF-814, etc.) and HMS-PP manufactured by Borealis (type name: WB130HMS, etc.) And HMS-PP manufactured by Dow (type name: D201, etc.).

  An index value indicating the degree of long-chain branching of polypropylene includes a branching index g represented by the following formula.

g = [η] _LB / [η] _Lin
Here, [η] _LB is the intrinsic viscosity of the polypropylene having a long chain branch, and [η] _Lin is the linear viscosity of a linear crystalline polypropylene having substantially the same weight average molecular weight as the polypropylene having a long chain branch. Intrinsic viscosity. The intrinsic viscosity shown here is measured at 135 ° C. by a known method for a sample dissolved in tetralin. In addition, the weight average molecular weight is determined by M.P. L. It is measured by the method described by McConnell in the American Laboratory, May, 63-75 (1978), ie, low angle laser light scattering photometry.

  The branching index g of the polypropylene satisfying the formula (1) contained in the biaxially stretched polypropylene film used for the base layer of the present invention is preferably 0.95 or less, more preferably 0.9 or less. When the branching index g exceeds 0.95, the effect of adding polypropylene satisfying the formula (1) is reduced, and the Young's modulus in the longitudinal direction of the film may be insufficient.

  The melt tension (MS) of the polypropylene satisfying the formula (1) contained in the biaxially oriented polypropylene film used for the base layer of the present invention is preferably in the range of 3 to 100 cN. If the MS is less than 3 cN, the Young's modulus in the longitudinal direction when the film is formed may be insufficient. Although the Young's modulus in the longitudinal direction tends to increase as the polypropylene having a large MS is used, if the MS exceeds 100 cN, the film forming property may be deteriorated. The MS of the polypropylene satisfying the formula (1) is more preferably 4 to 80 cN, further preferably 5 to 40 cN, and most preferably 5 to 35 cN.

  The mixing amount of the polypropylene satisfying the formula (1) contained in the biaxially oriented polypropylene film used in the base layer of the present invention is not particularly limited, but is preferably 1 to 60% by weight, and the effect can be seen even if a small amount is added. Is the feature. If the mixing amount is less than 1% by weight, the effect of improving the rigidity in the longitudinal direction may be small. If the mixing amount exceeds 60% by weight, the longitudinal stretchability may be deteriorated, and the impact resistance and haze of the film may be deteriorated. . The mixing amount of the polypropylene satisfying the formula (1) is more preferably 2 to 50% by weight, and further preferably 3 to 40% by weight.

  Another configuration of the present invention is that the relationship between the melt tension (MS) and the melt flow rate (MFR) of the polypropylene used for the biaxially oriented polypropylene film used for the base layer of the present invention satisfies the following expression (2). .

log (MS)>-0.61 log (MFR) +0.52 (2)
The polypropylene used for the biaxially oriented polypropylene film used for the base layer of the present invention has a high rigidity in the longitudinal direction, which has been difficult in the general-purpose longitudinal-horizontal sequential biaxial stretching method, by satisfying the formula (2). An axially stretched polypropylene film can be manufactured.

  The polypropylene used for the biaxially oriented polypropylene film used for the base layer of the present invention more preferably satisfies the formula (2 ′), and particularly preferably satisfies the formula (2 ″). These can be prepared, for example, by the addition amount of HMS-PP, and the rigidity in the longitudinal direction can be further improved.

log (MS)>-0.61 log (MFR) +0.56 (2 ')
log (MS)> -0.61 log (MFR) + 0.62 (2 ")
The polypropylene satisfying the above formula (2) may be, for example, a mixture of a so-called high melt tension polypropylene (High Melt Strength-PP; hereinafter, referred to as HMS-PP) and a general-purpose polypropylene, which has a high melt tension (MS). It can be obtained by introducing a long-chain branched component into the chain skeleton by copolymerization, graft polymerization or the like to increase the melt tension of polypropylene. By mixing such HMS-PP, rearrangement of the longitudinally oriented crystals in the width direction during transverse stretching can be suppressed.

  In addition, the melt flow rate (MFR) of the polypropylene used for the biaxially oriented polypropylene film used for the base layer of the present invention is preferably in the range of 1 to 30 g / 10 minutes from the viewpoint of film forming properties. If the MFR is less than 1 g / 10 minutes, problems such as an increase in filtration pressure during melt extrusion and a long time required for replacement of extruded raw materials may occur. If the MFR exceeds 30 g / 10 minutes, there may be a problem that the thickness unevenness of the formed film becomes large. MFR is more preferably 1 to 20 g / 10 min.

The mesopentad fraction (mmmm) of the polypropylene used for the biaxially stretched polypropylene film used for the base layer of the present invention is preferably 90 to 99.5%, more preferably 94 to 99.5%. Here, mmmm is an index that directly reflects the isotactic three-dimensional structure of polypropylene. In addition, mmmm as used herein means the ratio of the corrected integrated area of the mmmm peak to the total integrated area calculated in the specific range shown below, from each spectrum derived from the methyl group obtained by ¹³ C-NMR as shown below. Is measured five times for each sample, and is the average value calculated from these. By setting the mmmm to 90 to 99.5%, a film having excellent dimensional stability and markedly improved heat resistance, rigidity, moisture resistance, chemical resistance, and the like can be stably manufactured, so that printing, coating, and vapor deposition can be performed. It is possible to provide a film having high secondary workability in a film processing step such as bag making and laminating. When the mmmm is less than 90%, the stiffness of the film is reduced, and the heat shrinkage tends to increase, so that the secondary workability such as printing, coating, vapor deposition, bag making and laminating is reduced. In some cases, the water vapor transmission rate may also increase. When mmmm exceeds 99.5%, the film forming property may be reduced. mmmm is more preferably 95-99%, most preferably 96-98.5%.

  The isotactic index (II) of the polypropylene used for the biaxially oriented polypropylene film used for the base layer of the present invention is preferably in the range of 92 to 99.8%. When II is less than 92%, problems such as a decrease in stiffness when formed into a film, an increase in heat shrinkage, and deterioration in moisture resistance may occur. If II exceeds 99.8%, the film-forming properties may deteriorate. II is more preferably 94 to 99.5%.

  The polypropylene used for the biaxially oriented polypropylene film used for the base layer of the present invention is produced from the viewpoint of economy, etc., when manufacturing the biaxially oriented polypropylene film used for the base layer of the present invention, as long as the characteristics of the present invention are not impaired. It is also possible to use a blend of a waste film, a waste film produced during the production of another film, and other resins. In this case, it is necessary for the blended polypropylene to satisfy the above formula (2) from the viewpoint of improving the rigidity in the longitudinal direction.

  The polypropylene used for the biaxially oriented polypropylene film used for the base layer of the present invention is mainly composed of a homopolymer of propylene, and the monomer components of propylene and other unsaturated hydrocarbons are copolymerized within a range that does not impair the object of the present invention. May be blended, a polymer in which propylene and a monomer component other than propylene are copolymerized may be blended, or a copolymer of an unsaturated hydrocarbon monomer component other than propylene may be used. ) Polymers may be blended. Examples of such a copolymer component or a monomer component constituting the blend include ethylene, propylene (in the case of a copolymerized blend), 1-butene, 1-pentene, 3-methylpentene-1,3 -Methylbutene-1, 1-hexene, 4-methylpentene-1, 5-ethylhexene-1, 1-octene, 1-decene, 1-dodecene, vinylcyclohexene, styrene, allylbenzene, cyclopentene, norbornene, 5-methyl -2-norbornene and the like.

  Here, the characteristic values of polypropylene such as the above-mentioned melt tension (MS), melt flow rate (MFR), g value, meso pentad fraction (mmmm), and isotactic index (II) are based on the raw material chips before film formation. It is desirable to use and judge, but extract the film after film formation or metal deposition with n-heptane at a temperature of 60 ° C or less for 2 hours or more, remove impurities and additives, and vacuum at 130 ° C for 2 hours or more. It can also be measured using a dried sample as a sample.

  Next, the biaxially stretched polypropylene film used for the base layer of the present invention is compatible with polypropylene from the viewpoint of strengthening, gas barrier property improvement, film formability improvement, etc., and an additive capable of having a plasticizing effect at the time of stretching. Are mixed. The additive capable of providing a plasticizing effect here refers to a stretching aid that enables stable high-magnification stretching. If such additives are not mixed, the effect of suppressing the rearrangement of the oriented crystals in the width direction by HMS-PP cannot be sufficiently exerted, and the film-forming properties and gas barrier properties are also inferior. As such additives, at least one kind of petroleum resin substantially free of polar groups and / or terpene resin substantially free of polar groups is preferably used from the viewpoint of high draw ratio, strengthening and improvement of gas barrier properties. Can be

  Here, the petroleum resin substantially free of a polar group is a petroleum resin having no polar group such as a hydroxyl group, a carboxyl group, a halogen group, a sulfone group or a modified form thereof, and specifically, a petroleum resin. It is a resin based on cyclopentadiene or higher olefin hydrocarbons, which are based on unsaturated hydrocarbons.

  Further, the glass transition temperature (hereinafter sometimes abbreviated as Tg) of the petroleum resin substantially free of such a polar group is preferably 60 ° C. or higher. If Tg is less than 60 ° C., the effect of improving rigidity may be reduced.

  A hydrogenated (hereinafter sometimes abbreviated as hydrogenation) petroleum resin obtained by adding hydrogen to such a petroleum resin and setting the hydrogenation rate to 90% or more, preferably 99% or more, is particularly preferably used. Representative hydrogenated petroleum resins include, for example, alicyclic petroleum resins such as polydicyclopentadiene having a Tg of 70 ° C. or more and a hydrogenation rate of 99% or more.

The terpene resin substantially free of a polar group is a terpene resin having no polar group consisting of a hydroxyl group, an aldehyde group, a ketone group, a carboxyl group, a halogen group, a sulfone group or a modified form thereof, that is, ( C ₅ H ₈ ) n are hydrocarbons having the composition and modified compounds derived therefrom. Here, n is a natural number of about 2 to 20.

  Terpene resins are sometimes referred to as terpenoids, and typical compounds include pinene, dipentene, karen, myrcene, ocimene, limonene, terpinolene, terpinene, sabinene, tricyclene, bisabolene, zingiperene, santalen, camphorene, millen, and totalen. In the case of the biaxially oriented polypropylene film used for the base layer of the present invention, hydrogen is added, and the hydrogenation rate is preferably at least 90%, particularly preferably at least 99%. Among them, hydrogenated β-pinene, hydrogenated β-dipentene and the like are particularly preferably used.

  The bromine value of the petroleum resin or terpene resin is preferably 10 or less, more preferably 5 or less, and particularly preferably 1 or less.

  The additive amount of the above-mentioned additive may be an amount in which the plasticizing effect is exhibited, but it is preferable that the total amount of the petroleum resin and the terpene resin is 0.1 to 30% by weight. If the mixing amount of the resin is less than 0.1% by weight, the effect of improving the stretchability and the rigidity in the longitudinal direction may be reduced, or the transparency may be deteriorated. On the other hand, if it exceeds 30% by weight, the thermal dimensional stability deteriorates, the additive bleeds out to the surface layer of the film, the slipperiness may deteriorate, or the films may be blocked. The mixing amount of the additive is more preferably 1 to 20% by weight, and further preferably 2 to 15% by weight, in total with the addition amount of the petroleum resin and the terpene resin.

  When a petroleum resin containing a polar group and / or a terpene resin is used as an additive, voids are easily formed inside the film due to poor compatibility with polypropylene, and the water vapor permeability increases, In addition, the bleed out of the antistatic agent and the lubricant may be deteriorated.

  Specific examples of the additive which is compatible with such polypropylene and can have a plasticizing effect at the time of stretching include, for example, “Escolets” (type name: E5300 series, etc.) manufactured by Tonex Corporation and “Yashara Chemical Co., Ltd.” Clearon "(type name: P-125 and the like)," Arucon "(type name: P-125 and the like) manufactured by Arakawa Chemical Industries, Ltd., and the like.

  The metal-deposited biaxially-stretched polypropylene film of the present invention is a metal-deposited film having high gas barrier properties by using the above-mentioned biaxially-stretched polypropylene film for the base layer and providing the metal-deposited layer on at least one surface of the base layer. In addition, the biaxially oriented polypropylene film used for the base layer of the present invention has high rigidity in the longitudinal direction and is excellent in tensile strength. It is possible to suppress a decrease in gas barrier property of the deposited film after secondary processing such as printing, coating, laminating, and bag making.

  In addition, the metal-deposited biaxially stretched polypropylene film of the present invention can be a metal-deposited film having a higher gas barrier property by providing a coating layer of a polyester urethane resin between the base layer and the metal-deposited layer. it can.

  In order to obtain excellent gas barrier properties after metal deposition, the coating layer is applied with a mixed coating of a water-soluble and / or water-dispersible, crosslinked polyester urethane-based resin and a water-soluble organic solvent, and dried. It is preferable that it is formed by this.

  The polyester urethane resin used for the coating layer is composed of a polyester polyol obtained by esterifying a dicarboxylic acid and a diol component, a polyisocyanate, and if necessary, a chain extender.

  The dicarboxylic acid component of the polyester urethane resin used for the coating layer includes terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, trimethyladipic acid, sebacic acid, malonic acid, dimethylmalonic acid, succinic acid, glutar Acid, pimelic acid, 2,2-dimethylglutaric acid, azelaic acid, fumaric acid, maleic acid, itaconic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid For example, 1,4-naphthalic acid, diphenic acid, 4,4′-oxybenzoic acid, 2,5-naphthalenedicarboxylic acid and the like can be used.

  The diol component of the polyester urethane resin used for the coating layer includes ethylene glycol, 1,4-butanediol, aliphatic glycols such as triethylene glycol, aromatic diols such as 1,4-cyclohexanedimethanol, polyethylene glycol, And poly (oxyalkylene) glycols such as polypropylene glycol and polytetramethylene glycol.

  In addition, the polyester urethane resin used for the coating layer may be copolymerized with an oxycarboxylic acid such as p-oxybenzoic acid or acrylic acid (and a derivative thereof) in addition to the dicarboxylic acid component and the diol component. Although these have a linear structure, they can be made into a branched polyester by using a trivalent or higher ester-forming component.

  As polyisocyanates, hexamethylene diisocyanate, diphenylmethane diisocyanate, tolylene diisocyanate, isophorone diisocyanate, tetramethylene diisocyanate, xylylene diisocyanate, lysine diisocyanate, adduct of tolylene diisocyanate and trimethylol propane, addition of hexamethylene diisocyanate and trimethylol ethane Things and the like.

  Examples of the chain extender include pendant carboxyl group-containing diols and glycols such as ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, hexamethylene glycol, and neopentyl glycol, and ethylene diamine, propylene diamine, and hexane. Diamines such as methylenediamine, phenylenediamine, tolylenediamine, diphenyldiamine, diaminodiphenylmethane, diaminodiphenylmethane, diaminocyclohexylmethane and the like can be mentioned.

  Specific examples of the polyester urethane-based resin include "Hydran" (type name: AP-40F, etc.) manufactured by Dainippon Ink and Chemicals, Inc.

  When forming the coating layer, N-methylpyrrolidone, ethyl cellosolve acetate, dimethylformamide as a water-soluble organic solvent in the coating agent, in order to improve the film formability of the coating layer and the adhesion to the base layer. It is preferable to add at least one or more. In particular, N-methylpyrrolidone is preferred because it has a large effect of improving the film formability and adhesion to the substrate. The addition amount is preferably 1 to 15 parts by weight based on 100 parts by weight of the polyester urethane resin from the viewpoint of the flammability of the coating agent and prevention of odor deterioration, and more preferably 3 to 10 parts by weight.

  Further, it is preferable to introduce a crosslinked structure into the water-dispersible polyester urethane-based resin to enhance the adhesiveness between the coating layer and the base layer. As a method for obtaining such a coating liquid, there are the methods described in JP-A-63-15816, JP-A-63-256661, and JP-A-5-152159. As the crosslinkable component, addition of at least one crosslinking agent selected from isocyanate compounds, epoxy compounds and amine compounds can be mentioned. These cross-linking agents cross-link with the above-mentioned polyester urethane-based resin to enhance the adhesion between the base layer and the metal deposition layer.

  Examples of the isocyanate-based compound used as the crosslinking agent include, but are not limited to, the above-mentioned toluene diisocyanate, xylene diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate.

  Examples of the epoxy compound used as a crosslinking agent include diglycidyl ether of bisphenol A and oligomers thereof, diglycidyl ether of hydrogenated bisphenol A and oligomers thereof, diglycidyl ether orthophthalate, diglycidyl ether isophthalate, and terephthalic acid. Examples thereof include, but are not limited to, diglycidyl ether and adipic acid diglycidyl ether.

  Examples of the amine compound used as the crosslinking agent include amine compounds such as melamine, urea, and benzoguanamine; amino resins obtained by addition condensation of the above amino compound with formaldehyde or an alcohol having 1 to 6 carbon atoms; hexamethylene diamine; Examples include, but are not limited to, ethanolamine.

  From the viewpoint of food hygiene and adhesion to the substrate, it is preferable to add an amine compound to the coating layer. Specific examples of the amine compound used as the crosslinking agent include “Beckamine” (type name: APM, etc.) manufactured by Dainippon Ink and Chemicals, Inc.

  The amount of the crosslinking agent selected from the group consisting of an isocyanate compound, an epoxy compound and an amine compound is preferably 1 to 15 parts by weight with respect to 100 parts by weight of a mixed coating of the water-soluble polyester urethane resin and the water-soluble organic solvent. The amount is preferably from the viewpoint of improving chemical properties and preventing deterioration of water resistance, and more preferably 3 to 10 parts by weight. If the amount of the crosslinking agent is less than the above range, the effect of improving the adhesiveness may not be obtained.If the amount exceeds the above range, the coating layer and the base layer are presumed to be due to the unreacted remaining crosslinking agent. In some cases, a decrease in the adhesiveness may be observed.

  In addition, a small amount of a cross-linking accelerator may be added to the coating layer in order to completely cross-link and cure the above-described coating layer composition within the time for forming the metal deposition film.

  As the crosslinking accelerator to be added to the coating layer, a water-soluble acidic compound is preferable since the crosslinking promoting effect is large. Examples of the crosslinking accelerator include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, trimethyladipic acid, sebacic acid, malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, sulfonic acid, and pimelic acid 2,2-dimethylglutaric acid, azelaic acid, fumaric acid, maleic acid, itaconic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,4 -Naphthalic acid, diphenic acid, 4,4'-oxybenzoic acid, 2,5-naphthalenedicarboxylic acid and the like can be used.

  Specific examples of these crosslinking accelerators include "Catalyst" (type name: PTS, etc.) manufactured by Dainippon Ink and Chemicals, Inc.

  In addition, inert particles may be added to the coating layer.As the inert particles, inorganic fillers such as silica, alumina, calcium carbonate, barium sulfate, magnesium oxide, zinc oxide, and titanium oxide, and, for example, And organic polymer particles such as crosslinked polystyrene particles, crosslinked acryl particles, and crosslinked silicon particles. In addition to the inert particles, a wax-based lubricant and a mixture thereof may be added.

  The coating layer is preferably provided with a thickness of 0.05 to 2 μm. If the thickness of the coating layer is less than 0.05 μm, the adhesion to the base layer may be deteriorated, resulting in fine film detachment, and the gas barrier performance after metal deposition may be deteriorated. If the coating layer is thicker than 2 μm, it takes time to cure the coating layer, and the above-mentioned crosslinking reaction may be incomplete and the gas barrier performance may deteriorate, and the coating layer may be formed on the base layer during a film forming process. In the case of providing, the collecting property of the film dust to the base layer is deteriorated, a large number of internal voids are formed around the resin of the coating layer, and the mechanical properties may be deteriorated. More preferably, it is 0.08 to 1.5 μm, further preferably 0.1 to 1 μm.

  Further, the adhesive strength between the coating layer and the base layer is preferably 0.6 N / cm or more. When the adhesive strength between the coating layer and the base layer is less than the above range, the coating layer may be easily peeled off in the processing step, and the use restriction may be increased. The adhesive strength between the coating layer and the base layer is preferably 0.8 N / cm or more, and more preferably 1.0 N / cm or more. The upper limit of the adhesive strength between the coating layer and the base layer is not particularly limited as long as the effects of the present invention are exerted. For example, when the coating layer is formed in a film manufacturing process as described below, the film forming property is deteriorated. In some cases, the concentration is preferably 10 N / cm or less.

  The center line average roughness (Ra) of the metal-deposited surface of the biaxially stretched polypropylene film used for the base layer of the present invention is preferably equal to or less than the thickness of the metal-deposited layer from the viewpoint of gas barrier performance. More preferably, there is. If Ra exceeds 500 nm, when a metal-deposited film in which a coating layer and a metal-deposited layer are sequentially formed, pinholes or the like are generated in the aluminum film, and the gas barrier property may be deteriorated. Although there is no particular lower limit, Ra is preferably 0.1 nm or more from the viewpoint of handling properties such as slipperiness and blocking prevention. Ra is more preferably 300 nm or less, further preferably 100 nm or less, and most preferably 50 nm or less. Further, when a film having a coating layer provided on at least one side of the base layer, a smoother surface may be obtained than when the film is not provided, and Ra of the coating layer surface after coating is 50 nm or less from the viewpoint of gas barrier performance. Is more preferably 40 nm or less, and most preferably 30 nm or less. Furthermore, in both the case where the coating layer is not provided and the case where the coating layer is provided, it is preferable that Ra on the metal deposition surface of the film after the deposition satisfies the above range.

  In addition, the surface gloss of the biaxially stretched polypropylene film used for the base layer of the present invention is preferably 135% or more, more preferably 138% or more, for the beautiful metallic gloss after vapor deposition. Further, it is preferable that the above range is satisfied also when the film is provided with a coating layer.

  In the present invention, as a method of providing a coating layer, a method of applying a coating liquid outside a polypropylene film manufacturing process using a reverse roll coater, a gravure coater, a rod coater, an air doctor coater or a known coating device other than these is preferable. More preferably, as a method of applying the coating layer in the film manufacturing process, a coating liquid is applied to a polypropylene unstretched film, a method of successively biaxially stretching, a method of applying to a uniaxially stretched polypropylene film, and a further uniaxial stretching. There is a method of stretching in a direction perpendicular to the direction. Of these, the method of applying the film to a uniaxially stretched polypropylene film and further stretching the film in a direction perpendicular to the direction of the uniaxial stretching is most preferable because the thickness of the coating layer is made uniform and the productivity is improved.

  Furthermore, the metal-deposited biaxially stretched polypropylene film of the present invention has an overcoat layer provided on the metal-deposited layer, whereby the overcoat layer acts as a protective layer for the metal-deposited layer, In addition to suppressing the occurrence of defects such as abrasions and cracks, the overcoat layer covers the defects generated in the metal deposition layer and can suppress the flow of gas into the defects, so that the deterioration of the gas barrier properties can be further suppressed. Furthermore, by appropriately selecting an appropriate overcoat layer composition, secondary workability such as printability and lamination suitability can be improved, and gas barrier properties can be further enhanced.

  As the overcoat layer, a known thermoplastic resin or thermosetting resin exhibiting any of the above effects can be used. For example, when the purpose is to improve the gas barrier properties as described above, polyvinylidene chloride ( And known resins such as ethylene-vinyl alcohol copolymer (and its copolymer) and polyglycolic acid (and its copolymer), which are generally called gas barrier resins. However, it is not preferable to use polyvinylidene chloride (and its copolymer) in view of the influence on the environment as described above). In the present invention, it is particularly preferable to use the above-defined polyester urethane-based resin from the viewpoint of the above-described protective properties of the deposited layer, suitability for secondary processing, and further, the adhesion to the deposited layer.

  As a technique for providing the overcoat layer, a known technique such as extrusion lamination or coating can be used. When the polyester urethane-based resin is used as the overcoat layer in the present invention, it is preferable to use a known coating apparatus similar to the case where the coating layer is provided. In addition, as a preferable method of providing the coating layer and the overcoat layer in one step, a device for setting the coating layer and the overcoat layer is provided before and after the continuous vacuum vapor deposition machine, and the setting of the coating layer → metal deposition → overcoating. There can be mentioned a method of continuously setting the layers.

  In the biaxially stretched polypropylene film used for the base layer of the present invention, it is preferable not to add an organic lubricant such as fatty acid amide or an antistatic agent to the polypropylene of the base layer from the viewpoint of the adhesion of the coating layer and the metal deposition layer. However, it is permissible to add a small amount of organic crosslinkable particles or inorganic particles in order to impart slipperiness and improve workability and winding property. Examples of the organic crosslinkable particles added to the polypropylene of the base layer in a small amount include crosslinked silicone particles, crosslinked polymethyl methacrylate particles, crosslinked polystyrene particles, and the like, and inorganic particles include zeolite, calcium carbonate, silicon oxide, and aluminum silicate. can do. The average particle size of these particles is preferably 0.5 to 5 μm. If the average particle size is less than the above range, the slipperiness may deteriorate, and if the average particle size exceeds the above range, the particles may fall off, the transparency may deteriorate, or the film surface may be easily damaged when the films are rubbed. There is.

  The amount of the organic crosslinkable particles and / or inorganic particles added is preferably in the range of 0.02% by weight to 0.5% by weight, more preferably in the range of 0.05% by weight to 0.2% by weight. Is preferred in terms of anti-blocking properties, slipperiness and transparency.

  The biaxially oriented polypropylene film used for the base layer of the present invention may be added with a nucleating agent other than those described above, a heat stabilizer, an antioxidant, and the like, if necessary.

  For example, as a nucleating agent, a sorbitol type, an organic phosphate metal salt type, an organic carboxylic acid metal salt type, a rosin type nucleating agent, etc. are 0.5% by weight or less, and as a heat stabilizer, 2,6-di- 0.5% by weight or less of tert-butyl-4-methylphenol (BHT) and the like, and tetrakis- (methylene- (3,5-di-3-tert-butyl-4-hydroxy-hydro-hydro) as an antioxidant Cinnamate)) butane (Irganox 1010) or the like may be added in a range of 0.5% by weight or less.

  Next, the base layer of the present invention, on at least one side of the above-described biaxially stretched polypropylene film, to improve the adhesive strength of the metal deposition layer and the base layer, or the coating layer and the base layer, or for other purposes, the additive Bleed-out / scatter control, easy adhesion of coating film / deposited film, easy printability, heat sealability, print lamination, gloss, haze reduction (transparency), mold release, easy peelability, Depending on various purposes, such as imparting slip properties, improving surface hardness, imparting smoothness, improving surface roughness, improving gas barrier properties, imparting hand-cutting properties, a known polyolefin resin and other resins may be appropriately laminated. preferable.

  In this case, the lamination thickness is preferably 0.25 μm or more and 以上 or less of the total thickness of the film. If the lamination thickness is less than 0.25 μm, uniform lamination becomes difficult due to film breakage, etc., and if it exceeds の of the total thickness, the influence of the surface layer on the mechanical properties increases, causing a decrease in Young's modulus. The tensile strength of the film also decreases.

  In addition, the surface resin to be laminated at this time does not necessarily have to satisfy the scope of the present invention, and examples of the lamination method include coextrusion, inline / offline extrusion lamination, and inline / offline coating, but are limited to any of these. It does not mean that the best method can be selected at any time.

  Specific examples of the laminate include, for example, a second biaxially stretched polypropylene film layer (A layer) formed on one side of a specific biaxially stretched polypropylene film layer (A layer) in order to improve the adhesive strength with a metal deposition layer or a coating layer. A three-layer laminated film in which a layer is laminated and a third layer made of a heat-sealing resin made of a propylene-based copolymer is laminated on the other surface (laminated structure: second layer / A) Layer / third layer, a coating layer or a metallized layer on the second layer). Preferred embodiments in this case are described below, but the present invention is not limited thereto.

  As the resin used for the second layer, for example, ethylene vinyl alcohol, polyvinyl alcohol, polyester resin, polyamide resin, maleic anhydride-grafted polypropylene, acrylic acid-grafted polypropylene, ethylene-propylene random copolymer, ethylene -Propylene-butene random copolymer, homopolypropylene, polymethylpentene, polyetheramide, polyurethane-based resin, and the like, and at least one or more of these resins or a resin obtained by mixing two or more thereof, or One or more easy-adhesion layers may be laminated in order to maintain the adhesion between the first layer and the A layer (laminated structure: second layer / easily-adhesive layer / A layer / third layer). Among these, maleic anhydride-grafted polypropylene, acrylic acid-grafted polypropylene, ethylene-propylene random copolymer, ethylene-propylene-butene random copolymer, from the viewpoints of co-extrusion property, adhesiveness and co-stretchability with layer A It is more preferable to use a polypropylene resin such as homopolypropylene.

  The homopolypropylene resin preferably has a mesopentad fraction (mmmm) of 70 to 90%. When mmmm is less than the above range, the surface roughness increases, and the gas barrier property may be deteriorated after metal deposition. If the mmmm exceeds the above range, the adhesion to the metal vapor deposition layer is reduced, and fine film detachment occurs, which may undesirably deteriorate gas barrier properties.

  Further, as the resin used for the second layer, the above-mentioned mmmm was mixed with 70 to 90% of homopolypropylene and an ethylene / propylene copolymer so that the ethylene content of the whole resin was 0.1 to 2% by weight. It is even more preferable to use a resin composition from the viewpoint of adhesion to a metal deposition layer, handling properties, and the like. If the ethylene content of the entire resin is less than the above range, the adhesiveness may decrease, and if it exceeds the above range, the film adheres to the longitudinal stretching roll at the time of film formation, and a decrease in gloss due to the adhesion mark becomes a problem. There is.

  The ethylene / propylene random copolymer has an ethylene copolymerization amount of preferably 6% by weight or less, more preferably 4.5% by weight or less. If the ethylene copolymerization amount exceeds the above range, the film sticks to the longitudinal stretching roll at the time of film formation, and a decrease in gloss due to the sticking mark may become a problem.

  As the propylene-based copolymer used in the third layer, for example, a homopolypropylene, an ethylene-propylene random copolymer, an ethylene-propylene block copolymer, an ethylene-propylene-butene copolymer, and a metallocene catalyst were used. Examples include polypropylene or an ethylene / propylene copolymer. Further, a low-density polyethylene or a high-density polyethylene may be added to the propylene-based copolymer as long as the transparency is not reduced.

  Further, in order to impart a lubricity to the third layer, a polypropylene-based copolymer obtained by adding the same organic crosslinkable particles or inorganic particles as described above, an ethylene-propylene block copolymer, an ethylene-propylene It is preferable to add a mixture of a block copolymer and high-density polyethylene.

  As for the heat sealing property of the third layer, two sheets of the above-described three-layer laminated film (the evaluation may be performed in any case before and after the vapor deposition) are performed by stacking the third layers together at a temperature of 120. The metal-sealed biaxially stretched polypropylene film of the present invention was used as a food packaging bag when the heat sealing strength was 1 N / cm or more when heat-sealed under the conditions of ° C, a pressure of 0.1 MPa, and a pressure time of 1 sec. Occasionally, it is preferable from the viewpoint of protecting the contents.

  Furthermore, the metal-deposited biaxially stretched polypropylene film of the present invention may be formed by laminating one or more layers of a known thermoplastic resin on at least one surface of the film by a similar method according to the above-mentioned purpose.

  By subjecting at least one film surface of the biaxially stretched polypropylene film used for the base layer of the present invention to a corona discharge treatment so that the film surface has a wet tension of 35 mN / m or more, printability, adhesiveness, in particular, metal deposition layer or It can be preferably used to improve the adhesiveness to the coating layer. As the atmosphere gas at the time of corona discharge treatment, air, oxygen, nitrogen, carbon dioxide gas, or a mixed system of nitrogen / carbon dioxide gas is preferable, and from the viewpoint of economy, corona discharge treatment in air is particularly preferable. Further, a flame (flame) treatment, a plasma treatment or the like is also preferable from the viewpoint of improving the surface wetting tension.

  The longitudinal Young's modulus (Y (MD)) at 25 ° C. of the biaxially oriented polypropylene film used for the base layer of the present invention is preferably 2.5 GPa or more. If Y (MD) at 25 ° C. is less than 2.5 GPa, the rigidity in the width direction is higher than that in the longitudinal direction, and the rigidity may be unbalanced. For this reason, the stiffness of the film may be insufficient, and during film processing such as printing, laminating, coating, and bag making, a film crack (crack) of the vapor-deposited layer is generated, and the gas barrier property is deteriorated. May be insufficient. The Y (MD) at 25 ° C. is the cooling drum temperature and the longitudinal stretching conditions (temperature, temperature, etc.) when the biaxially oriented polypropylene film used for the base layer of the present invention is cooled and solidified from a molten state to obtain an unoriented sheet. Magnification, etc.), the crystallinity of the polypropylene to be used (corresponding to mesopentad fraction (mmmm), isotactic index (II), etc.), the amount of additives that can have a plasticizing effect during stretching, and the like can be controlled. . Therefore, optimal film forming conditions and raw materials may be appropriately selected within a range that does not impair the characteristics of the present invention. Y (MD) at 25 ° C. is more preferably 2.7 GPa or more, still more preferably 3.0 GPa or more, and most preferably 3.2 GPa or more. Further, the metal-deposited biaxially stretched polypropylene film of the present invention preferably satisfies the above range.

  The longitudinal Young's modulus (Y (MD)) at 80 ° C. of the biaxially oriented polypropylene film used for the base layer of the present invention is preferably 0.4 GPa or more. When Y (MD) at 80 ° C. is less than 0.4 GPa, the rigidity in the width direction is higher than that in the longitudinal direction, and the rigidity may be unbalanced. For this reason, the film may be insufficiently stiff, and the film has a high tensile strength, such as a film crack (crack) of the deposited layer during the film processing such as printing, laminating, coating, and bag making, resulting in deterioration of gas barrier properties. May be insufficient. The Y (MD) at 80 ° C. is the cooling drum temperature and the longitudinal stretching conditions (temperature, Magnification, etc.), the crystallinity of the polypropylene to be used (corresponding to mesopentad fraction (mmmm), isotactic index (II), etc.), the amount of additives that can have a plasticizing effect during stretching, and the like can be controlled. . Therefore, optimal film forming conditions and raw materials may be appropriately selected within a range that does not impair the characteristics of the present invention. Y (MD) at 80 ° C. is more preferably 0.5 GPa or more, further preferably 0.6 GPa or more. Further, the metal-deposited biaxially stretched polypropylene film of the present invention preferably satisfies the above range.

The biaxially stretched polypropylene film used for the base layer of the present invention has an m value represented by a Young's modulus (Y (MD)) in the longitudinal direction and a Young's modulus (Y (TD)) in the width direction m = Y (MD) / ( Y (MD) + Y (TD))
Is preferably in the range of 0.4 to 0.7 at 25 ° C. Here, the m value is a ratio of the Young's modulus in the longitudinal direction to the sum of the Young's modulus in the longitudinal direction and the width direction. Therefore, a film having an m value of <0.5 has a higher rigidity in the width direction than that in the longitudinal direction, and a film having an m value of 0.5 has substantially balanced rigidity in the longitudinal direction and the width direction. Films with a value> 0.5 have higher rigidity in the longitudinal direction than in the width direction. When the m value is 0.4 to 0.7, a very strong film having a balanced rigidity can be obtained. If the m value at 25 ° C. is less than 0.4, the rigidity in the longitudinal direction is inferior to the width direction, and the rigidity may be unbalanced. For this reason, the film may be insufficiently stiff, and the film has a high tensile strength, such as a film crack (crack) of the deposited layer during the film processing such as printing, laminating, coating, and bag making, resulting in deterioration of gas barrier properties. May be insufficient. If the m value exceeds 0.7, the rigidity in the width direction is significantly reduced as compared with the longitudinal direction, and the stiffness of the film may be insufficient.

  The m value at 25 ° C. is the film forming conditions (the cooling drum temperature, the longitudinal and transverse stretching temperatures when cooling and solidifying from a molten state to obtain an unstretched sheet) in the production of the biaxially stretched polypropylene film used for the base layer of the present invention. , Magnification, relaxation of film after longitudinal and transverse stretching, crystallinity of polypropylene to be used (corresponding to mesopentad fraction (mmmm), isotactic index (II)), additive capable of having a plasticizing effect at the time of stretching Can be controlled by, for example, the amount of the mixture. Therefore, optimal film forming conditions and raw materials may be appropriately selected within a range that does not impair the characteristics of the present invention. The m value at 25 ° C. is more preferably 0.42 to 0.68, further preferably 0.44 to 0.65, and most preferably 0.46 to 0.62. Further, the metal-deposited biaxially stretched polypropylene film of the present invention preferably satisfies the above range. Further, the metal-deposited film may be heated to room temperature or higher in processing steps such as printing, laminating, and heat sealing, and the m value is in the above range even at room temperature or higher, from the viewpoint of secondary processing. Is preferred. In particular, the m value preferably satisfies the above range even at 80 ° C.

  Further, the biaxially oriented polypropylene film used for the base layer of the present invention preferably has an F2 value in the longitudinal direction at 25 ° C. of 40 MPa or more. Here, the F2 value in the longitudinal direction refers to a sample cut out at a size of 15 cm in the longitudinal direction and 1 cm in the width direction, when the original length is 50 mm and the elongation is 2% when stretched at a pulling speed of 300 mm / min. Such stress. If the F2 value in the longitudinal direction at 25 ° C. is less than 40 MPa, the rigidity in the width direction is higher than that in the longitudinal direction, and the rigidity may be unbalanced. For this reason, the stiffness of the film may be insufficient, and when the film is processed in printing, laminating, coating, bag making, etc., the vapor-deposited film may crack (crack) to deteriorate the gas barrier property. May be insufficient. The F2 value in the longitudinal direction at 25 ° C. is determined by the temperature of the cooling drum and the longitudinal stretching conditions (temperature) when the biaxially stretched polypropylene film used for the base layer of the present invention is cooled and solidified from a molten state to obtain an unstretched sheet. , Magnification, etc.), the crystallinity of the polypropylene to be used (corresponding to the mesopentad fraction (mmmm), the isotactic index (II), etc.), and the mixing amount of an additive capable of providing a plasticizing effect at the time of stretching. it can. Therefore, optimal film forming conditions and raw materials may be appropriately selected within a range that does not impair the characteristics of the present invention. The F2 value in the longitudinal direction at 25 ° C. is more preferably 45 MPa or more. Further, the metal-deposited biaxially stretched polypropylene film of the present invention preferably satisfies the above range.

  The F5 value in the longitudinal direction at 25 ° C. of the biaxially oriented polypropylene film used for the base layer of the present invention is preferably 50 MPa or more. Here, the F5 value in the longitudinal direction means that a sample cut out in a size of 15 cm in the longitudinal direction and 1 cm in the width direction is stretched at an original length of 50 mm and a tensile speed of 300 mm / min. Such stress. If the F5 value in the longitudinal direction at 25 ° C. is less than 50 MPa, the rigidity in the width direction is higher than that in the longitudinal direction, and the rigidity may be unbalanced. For this reason, the stiffness of the film may be insufficient, and when the film is processed in printing, laminating, coating, bag making, etc., the vapor-deposited film may crack (crack) to deteriorate the gas barrier property. May be insufficient. The F5 value in the longitudinal direction at 25 ° C. is determined by the temperature of the cooling drum and the longitudinal stretching conditions (temperature when the biaxially stretched polypropylene film used for the base layer of the present invention is produced by cooling and solidifying from a molten state to obtain an unstretched sheet. , Magnification, etc.), the crystallinity of the polypropylene to be used (corresponding to the mesopentad fraction (mmmm), the isotactic index (II), etc.), and the mixing amount of an additive capable of providing a plasticizing effect at the time of stretching. it can. Therefore, optimal film forming conditions and raw materials may be appropriately selected within a range that does not impair the characteristics of the present invention. The F5 value in the longitudinal direction at 25 ° C. is more preferably 55 MPa or more. Further, the metal-deposited biaxially stretched polypropylene film of the present invention preferably satisfies the above range.

  The biaxially oriented polypropylene film used for the base layer of the present invention preferably has a heat shrinkage in the longitudinal direction at 120 ° C. of 5% or less. If the heat shrinkage in the longitudinal direction at 120 ° C. exceeds 5%, the shrinkage of the film when a temperature is applied at the time of film processing such as printing, laminating, coating, bag making, etc. becomes large, resulting in film cracking and pitch. In some cases, process defects such as displacement and wrinkling may be induced. The heat shrinkage in the longitudinal direction at 120 ° C. is determined by the temperature of the cooling drum and the longitudinal and transverse stretching conditions when the unstretched sheet is obtained by cooling and solidifying from a molten state to obtain an unstretched sheet when producing the biaxially oriented polypropylene film of the base layer of the present invention. It can be controlled by (stretching temperature, magnification, relaxation of the film after stretching, etc.), crystallinity of the polypropylene used (corresponding to mmmm, II, etc.), and the amount of additives that can have a plasticizing effect at the time of stretching. Optimal longitudinal stretching conditions and raw materials may be appropriately selected within a range that does not impair the characteristics of the present invention. The heat shrinkage in the longitudinal direction at 120 ° C. is more preferably 4% or less. Further, the metal-deposited biaxially stretched polypropylene film of the present invention preferably satisfies the above range.

  The sum of the heat shrinkage in the longitudinal direction and the heat shrinkage in the width direction at 120 ° C. of the biaxially stretched polypropylene film used for the base layer of the present invention is preferably 8% or less. If the sum of the thermal shrinkage in the longitudinal direction and the thermal shrinkage in the width direction at 120 ° C. exceeds 8%, the film shrinks when a temperature is applied during film processing such as printing, laminating, coating, etc., and the film becomes large. Process defects such as cracks, pitch shifts, and wrinkles may be induced. The sum of the heat shrinkage ratio in the longitudinal direction and the width direction at 120 ° C. is determined according to the film forming conditions (when the unstretched sheet is obtained by cooling and solidifying from a molten state to obtain an unstretched sheet) in the production of the biaxially oriented polypropylene film of the base layer of the present invention. Cooling drum temperature, longitudinal and transverse stretching temperature, magnification, relaxation of film after longitudinal and transverse stretching, etc.) The optimum film-forming conditions and raw materials may be selected as appropriate within a range that can be controlled by the mixing amount and the like and do not impair the characteristics of the present invention. The sum of the heat shrinkage in the longitudinal direction and the heat shrinkage in the width direction at 120 ° C. is more preferably 6% or less. Further, the metal-deposited biaxially stretched polypropylene film of the present invention preferably satisfies the above range.

The water vapor transmission rate of the biaxially oriented polypropylene film used for the base layer of the present invention is preferably 1.5 g / m ² /d/0.1 mm or less. If the water vapor transmission rate exceeds 1.5 g / m ² /d/0.1 mm, for example, the moisture-proof property when the metal-deposited biaxially stretched polypropylene film of the present invention is used for a package for shielding the contents from the outside air. May be inferior. The water vapor transmission rate is determined based on film forming conditions (a cooling drum temperature, a longitudinal / lateral stretching temperature, a magnification, etc., when an unstretched sheet is obtained by cooling and solidifying from a molten state) when producing a biaxially oriented polypropylene film of the base layer of the present invention. ), The crystallinity of the polypropylene to be used (corresponding to mmmm, II, etc.), the amount of additives that can provide a plasticizing effect during stretching, and the like can be controlled, and are optimal as long as the characteristics of the present invention are not impaired. Film-forming conditions and raw materials may be selected. The water vapor transmission rate is more preferably 1.2 g / m ² /d/0.1 mm or less.

Known methods can be used to produce the biaxially oriented polypropylene film used for the base layer of the present invention. For example, the above equation (1)
log (MS)>-0.61 log (MFR) +0.82 (1)
Or a polypropylene containing polypropylene satisfying the formula (2)
log (MS)>-0.61 log (MFR) +0.52 (2)
A resin obtained by mixing at least one of a petroleum resin substantially free of a polar group and / or a terpene resin substantially free of a polar group into polypropylene satisfying the conditions described above; In the case of forming a laminate in which the layers are laminated, desired resins are prepared as needed. These resins are supplied to separate extruders, melted at a temperature of 200 to 290 ° C., passed through a filtration filter, merged in a short tube or a die, and extruded from a slit die at a desired lamination thickness. Then, it is wound around a cooling drum and cooled and solidified into a sheet to obtain an unstretched (laminated) film. It is preferable that the temperature of the cooling drum is 20 to 100 ° C. and that the film is appropriately crystallized from the viewpoint of improving the rigidity in the longitudinal direction.

  Next, the obtained unstretched (laminated) film is biaxially stretched using a known general-purpose longitudinal-lateral sequential biaxial stretching method. First, the unstretched film is preheated by passing through a roll maintained at a predetermined temperature, and then the film is maintained at a predetermined temperature and passed between rolls provided with a peripheral speed difference, stretched in the longitudinal direction, and immediately cooled to room temperature. I do. Here, an important point for producing a biaxially stretched polypropylene film highly strengthened in the longitudinal direction is a stretching ratio in the longitudinal direction (= longitudinal direction). The effective stretching ratio in the longitudinal direction when forming a normal longitudinal-lateral sequential biaxially stretched polypropylene film is in the range of 4.5 to 5.5 times, and if it exceeds 6 times, stable film formation becomes difficult. In contrast, the biaxially stretched polypropylene film used for the base layer of the present invention preferably has an effective stretch ratio of 6 times or more in the longitudinal direction, while the film is broken in the transverse stretch. If the effective stretching ratio in the machine direction is less than 6 times, the resulting film may have insufficient rigidity in the longitudinal direction, and the film may have insufficient rigidity when thinned. The effective stretching ratio in the machine direction is more preferably 7 times or more, and further preferably 8 times or more. At this time, it is sometimes preferable to perform the longitudinal stretching in at least two stages from the viewpoint of strengthening in the longitudinal direction and suppressing surface defects. The longitudinal stretching temperature may be appropriately selected from the viewpoints of stable film forming properties, suppression of thickness unevenness, and strengthening in the longitudinal direction, and is preferably 120 to 150 ° C. In the cooling process after the longitudinal stretching, it is preferable from the viewpoint of the dimensional stability in the longitudinal direction that the film is relaxed in the longitudinal direction so that the thickness unevenness of the film is not deteriorated.

  Subsequently, the longitudinally stretched film is guided to a tenter type stretching machine, preheated at a predetermined temperature, and stretched in the width direction. Here, the effective stretching ratio in the width direction is preferably 10 times or less. If the effective stretching ratio in the width direction exceeds 10 times, the obtained film may have insufficient rigidity in the longitudinal direction or may have an unstable film formation. The transverse stretching temperature may be appropriately selected from the viewpoint of stable film forming properties, thickness unevenness, and strengthening in the longitudinal direction, and is preferably 150 to 180 ° C.

  After stretching in the width direction, the sheet is heat-set at 150 to 180 ° C. while giving a relaxation of 1% or more in the width direction, and cooled. Further, if necessary, a corona discharge treatment is performed on the surface on which the metal deposition layer of the base layer is provided and / or the third surface on the opposite side in air, nitrogen, or a mixed atmosphere of carbon dioxide and nitrogen. At this time, when a heat seal layer is laminated as the third layer, it is preferable that the surface on the third layer side is not subjected to corona discharge treatment in order to obtain high adhesive strength. Next, the film is wound up to obtain a biaxially oriented polypropylene film used in the present invention.

  When a film with further improved gas barrier properties is obtained, the unstretched (laminated) film is stretched 6 times or more in the longitudinal direction, then cooled, and the above-mentioned coating layer is coated on the uniaxially stretched film base layer. The agent is coated (if necessary, the surface of the base layer on which the coating layer is to be formed is preferably subjected to corona discharge treatment in an atmosphere of air, nitrogen, or a mixture of carbon dioxide and nitrogen before forming the coating layer, if necessary), Next, it is introduced into a tenter type stretching machine and stretched 10 times or less in the width direction at 150 to 180 ° C., then subjected to relaxation heat treatment at 150 to 180 ° C. and cooled. Further, if necessary, the surface provided with the coating layer of the base layer and / or the surface of the third layer on the opposite side are subjected to corona discharge treatment in air, nitrogen, or a mixed atmosphere of carbon dioxide and nitrogen. At this time, when a heat seal layer is laminated as the third layer, it is preferable that the surface on the third layer side is not subjected to corona discharge treatment in order to obtain high adhesive strength. Next, the film is wound up to obtain a biaxially oriented polypropylene film for metal deposition.

  Aging the biaxially stretched polypropylene film for metal deposition at 40 to 60 ° C. stabilizes the structure (preferably crystallinity) of the film, improves the Young's modulus, and improves the adhesive strength with the metal deposited layer. This is preferable because the gas barrier performance is improved. In particular, when the coating layer is formed as described above, by promoting the reaction of the coating layer, the adhesive strength with the base layer is improved, the adhesive strength with the metal deposition layer is also improved, and the gas barrier performance is further improved. Therefore, it is preferable. The time for performing aging is preferably 12 hours or more from the viewpoint of improving the adhesive strength to the metal deposition layer and improving the chemical resistance, and more preferably 24 hours or more.

  Next, a metal deposition layer is formed on at least one surface of the biaxially stretched polypropylene film for metal deposition. The metal evaporation is preferably performed by vacuum evaporation of the metal, and the metal is evaporated from an evaporation source to form a metal evaporation layer. At this time, the method of transporting the film in the vapor deposition machine may be a batch type or a continuous type.

  Examples of the evaporation source include a boat type of a resistance heating type, a crucible type by radiation or high frequency heating, and a type by electron beam heating, but are not particularly limited.

  As the metal used for the metal-deposited layer of the metal-deposited biaxially stretched polypropylene film of the present invention, metals such as Al, Zn, Mg, Sn, and Si are preferable, but Ti, In, Cr, Ni, Cu, Pb, and Fe are preferred. Can also be used. These metals are preferably processed into granules, rods, tablets, wires, or crucibles having a purity of 99% or more, preferably 99.5% or more.

  In particular, among the deposited metals, it is preferable to provide an aluminum deposited layer on at least one surface of the base layer of the present invention from the viewpoints of durability, productivity, and cost of the metal deposited layer. At this time, other metal components such as nickel, copper, gold, silver, chromium, and zinc can be deposited simultaneously or successively with aluminum.

  The thickness of the metal deposition layer is preferably 10 nm or more in order to exhibit high gas barrier performance. More preferably, it is 20 nm or more. Although the upper limit of the vapor deposition layer is not particularly set, it is more preferably, for example, less than 500 nm from the viewpoint of economy and productivity. Compared with the conventional case where metal is vapor-deposited on a general-purpose biaxially stretched polypropylene film, the biaxially stretched polypropylene film used for the base layer of the present invention has a small elongation with respect to the tension applied during film transport. By vapor deposition, the metal deposition layer can be thickened.

  The gloss of the metal deposition layer is preferably at least 600%, more preferably at least 700%.

Further, the metal vapor deposition layer of the present invention may be a metal oxide vapor deposition film, and is suitably used as a transparent gas barrier film having excellent gas barrier properties, such as a film for transparent packaging. Here, the deposited film of a metal oxide is a coating of a metal oxide such as incomplete aluminum oxide or incomplete silicon oxide, and in particular, incomplete aluminum oxide is preferable in terms of durability, productivity, and cost of the deposited layer. . These vapor deposition methods can be performed by a known method. For example, in the case of an incomplete aluminum oxide film, the film is run in a high-vacuum apparatus having a degree of vacuum of 10 ⁻⁴ Torr or less, and the aluminum metal is heated and melted. Then, a small amount of oxygen gas is supplied to the evaporating point, and aluminum is oxidized to be agglomerated and deposited on the film surface. The thickness of the metal oxide deposited layer is preferably in the range of 10 to 50 nm, more preferably in the range of 10 to 30 nm. The degree of imperfection of the metal oxide vapor deposition layer is such that oxidation proceeds after vapor deposition and the light transmittance of the metal oxide vapor deposition film changes, and the light transmittance is preferably in the range of 70 to 90%. If the light transmittance is less than 70%, the content is not easily seen through the packaging bag, which is not preferable. Further, when the light transmittance exceeds 90%, it is not preferable because the gas barrier performance tends to be insufficient when used as a packaging bag.

  In the metal-deposited biaxially-stretched polypropylene film of the present invention, when a coating layer is not formed between the base layer and the metal-deposited layer, the adhesive strength between the biaxially-stretched polypropylene film and the metal-deposited layer or the metal-oxide-deposited layer is 0.3 N. / Cm or more, more preferably 0.5 N / cm or more. When a coating layer is formed between the base layer and the metal deposition layer, the adhesive strength between the biaxially stretched polypropylene film and the metal deposition layer or metal oxide deposition layer is preferably 0.6 N / cm or more, More preferably, it is 0.8 N / cm or more. In any case, if the adhesive strength is less than the above range, the deposited film is wound into a roll in a long length, and the deposited layer is peeled off when unwound during the secondary processing, and gas barrier performance may be deteriorated. . The upper limit of the adhesive strength between the deposited layer and the base layer is not particularly limited as long as the effects of the present invention are exhibited, but is preferably 5 N / cm or less, more preferably 3 N / cm.

  When an overcoat layer made of polyester urethane-based resin is formed on the metal-deposited layer, an overcoat layer coating agent is coated on the metal-deposited layer of the metal-deposited film, and hot air is applied at a temperature of 90 to 120 ° C. It may be dried. As in the case of forming the coating layer, when using a polyester urethane-based resin for the overcoat layer, it is preferable to perform the same aging after forming the overcoat layer.

The gas barrier performance of the metal-deposited biaxially stretched polypropylene film of the present invention is such that the water vapor transmission rate is 4 g / m ² / d or less, preferably 1 g / m ² / d or less, and the oxygen transmission rate is 1000 ml / m ^It is preferably at most ² / d / MPa, more preferably at most 500 ml / m ² / d / MPa when used as a food packaging bag. In addition, when a coating layer is formed on the base layer, the gas barrier performance of the metal-deposited biaxially stretched polypropylene film is significantly improved due to the effects of smoothing the surface and improving the adhesion to the metal-deposited layer. Is 1 g / m ² / d or less, preferably 0.5 g / m ² / d or less, and the oxygen permeability is 200 ml / m ² / d / MPa or less, preferably 100 ml / m ² / d / MPa or less. Is preferred when used as a food packaging bag.

  The metal-deposited biaxially stretched polypropylene film of the present invention has a biaxial structure in which the base layer has enhanced rigidity in the longitudinal direction without deteriorating important properties such as dimensional stability and moisture resistance as compared with the conventional biaxially stretched polypropylene film. By using a stretched polypropylene film, it exhibits excellent tensile strength against processing tension during film processing such as printing, laminating, coating, and bag making, and can suppress deterioration of gas barrier properties due to occurrence of film cracks (cracks). . In addition, compared to a conventional vapor-deposited film using a general-purpose biaxially oriented polypropylene film as a base layer, the rigidity in the longitudinal direction is high even at the same thickness, and since it has excellent gas barrier properties, the base layer is higher than that of a conventional metal-deposited biaxially oriented polypropylene film. Processing characteristics and gas barrier performance can be maintained even when the film is made thin.

  In addition, the metal-deposited biaxially stretched polypropylene film of the present invention can improve the secondary workability and gas barrier performance of the structure even when the film is used by being processed into a structure by being compounded with another film. . Furthermore, even if the film of the present invention or another film to be combined with the film of the present invention is appropriately thinned, the secondary workability as a component, gas barrier performance, and the like can be maintained, so that waste and resources are reduced. Can be reduced.

  From the above, the metal-deposited biaxially oriented polypropylene film of the present invention can be preferably used for packaging, industrial use, and the like.

[Method of measuring characteristic values]
The terms and measurement methods used in the present invention are described below.

(A) Melt tension (MS)
Melt tension (MS) was measured based on JIS K 7210 (1999). Using a melt tension tester manufactured by Toyo Seiki, the polypropylene is heated to 230 ° C., and the molten polypropylene is discharged at an extrusion speed of 15 mm / min to form a strand. The tension is measured when the strand is pulled at a rate of 6.5 m / min. Then, it was set as MS (unit: cN).

(A) Melt flow rate (MFR)
It was measured under the condition M (230 ° C., 2.16 kgf) according to JIS K 7210 (1999) (unit: g / 10 minutes).

(C) Thickness of the coating layer, the thickness of the metal deposition layer and the thickness of the metal oxide deposition layer Using a transmission electron microscope (TEM), ultrathin sections of the film were observed, and the lamination thickness and thickness configuration were measured.

(D) Adhesive strength The adhesive strength of the metal-deposited layer of the metal-deposited biaxially stretched polypropylene film is determined by applying a 20 μm-thick biaxially oriented polypropylene film (Toray S648) to the metal-deposited layer or metal oxide-deposited layer on a polyurethane-based material. After bonding with an adhesive and leaving at 40 ° C. for 48 hours, measurement was carried out by 90 ° peeling at a peeling speed of 10 cm / min using Tensilon manufactured by Toyo Baldwin with a width of 15 mm. The adhesive strength of the biaxially oriented polypropylene film of the coating layer and the base layer was determined by using a 20 μm-thick biaxially oriented polypropylene film (S648 manufactured by Toray Co., Ltd.) on the coating layer surface of the film before metal deposition using a polyurethane adhesive. And bonded in the same manner as above.

(E) Mesopentad fraction (mmmm)
Polypropylene is dissolved in a mixed solution of 1,2,4-trichlorobenzene (special grade reagent) and benzene-D6 at a ratio of 2: 1 (volume fraction), and ^13C -NMR is performed using a JEOL JNM-LAMBDA400 apparatus under the following conditions. A measurement was made.

Measurement concentration: 3wt%
Measurement solvent: 1,2,4-trichlorobenzene (reagent grade) / benzene-D6 2: 1 (volume fraction) mixed solution Sample tube: 5 mmφ
Measurement temperature: 125 ° C
Resonant frequency: 100.4MHz
Spin speed: 12Hz
Pulse width: 4.6 μs (flip angle 45 °)
Pulse repetition time: 5 seconds Data point: 32000
Number of integration: 20000 times Measurement mode: BCM (Bilebel complete decoupling) method.

  The obtained spectrum was subjected to a Fourier transform at a broadening factor of 0.26 Hz, and set to 21.855 ppm based on the mmmm peak. The obtained spectrum was assigned according to T.V. Based on the report of Hayashi et al. (Polymer, 29, p. 138-143 (1988)). The integrated area of each spectrum was calculated on a computer using the attached analysis software. In this case, the integration range of each spectrum is as follows.

Main peak: 22.34-21.48 ppm
mmmr peak: 21.64-21.52 ppm
rmmr peak: 21.44-21.27 ppm
mmrr peak: 21.13 to 20.99 ppm
(Mrmm + rmrr) peak: 20.94 to 20.73 ppm
rrrr peak: 20.47 to 20.27 ppm
rrrm peak: 20.24 to 20.09 ppm
mrrm peak: 20.07 to 19.87 ppm.

Here, the integrated area of the mmmm peak is defined as a peak integrated area including the spinning side band peak and the satellite peak. The integrated area of the main peak includes the integrated area of the mmmr peak in addition to the mmmm peak. Therefore, the integral area of the mmmm peak is calculated by the following equation by subtracting the integral area of the mmmr peak from the integral area of the main peak.
A (mmmm) = A (main)-A (mmmmr).

  Here, A (mmmm), A (main), and A (mmmr) are integrated areas of the mmmm peak, the main peak, and the mmmr peak, respectively.

  The same measurement was performed five times for each sample, and the average value of the data at three points excluding the maximum value and the minimum value was calculated and defined as the mesopentad fraction (mmmm, unit:%) of the polypropylene.

(F) Intrinsic viscosity ([η])
The polypropylene dissolved in tetralin at 135 ° C. was measured using an Ostwald viscometer manufactured by Mitsui Toatsu Chemicals, Inc.

(G) Isotactic index (II)
The polypropylene is extracted with n-heptane at a temperature of 60 ° C. for 2 hours to remove additives in the polypropylene resin. Thereafter, vacuum drying is performed at 130 ° C. for 2 hours. From this, a sample of weight W (mg) is taken, placed in a Soxhlet extractor and extracted with boiling n-heptane for 12 hours. Next, the sample was taken out, sufficiently washed with acetone, vacuum-dried at 130 ° C. for 6 hours, and then cooled to room temperature, the weight W ′ (mg) was measured, and it was determined by the following equation.

  II = (W '/ W) * 100 (%).

(H) Glass transition temperature (Tg)
A thermo-analyzer RDC220 manufactured by Seiko Instruments Inc. was loaded in an aluminum pan with a sample weight of 5 mg, heated at a rate of 20 ° C./min, and the built-in program of the company's thermal analysis system SSC5200 was obtained from the calorific curve obtained. The starting point of the glass transition was defined as the glass transition temperature (Tg).

(G) Bromine value It was measured according to JIS K 2605 (1996). It is represented by the number of g of bromine added to the unsaturated component in 100 g of the sample.

(U) Center line average surface roughness (Ra)
The measurement was performed using an atomic force microscope (AFM) and attached software under the following conditions. The measurement was performed five times for each sample, and the average value was defined as the center line average surface roughness (Ra, unit: nm). In the measurement, various conditions such as gain and amplitude were appropriately adjusted so that the image was not blurred, and when the image was still blurred, the cantilever was appropriately replaced.

Apparatus: NanoScope III AFM (manufactured by Digital Instruments)
Cantilever: silicon single crystal Scanning mode: tapping mode Scanning range: 1 μm × 1 μm
Scanning speed: 0.3 Hz.

(B) Film surface gloss (%)
Based on JIS Z8741 (1997), it was obtained as a 60 ° specular gloss using a digital variable angle gloss meter UGV-5D manufactured by Suga Test Instruments (unit:%).

(S) Average particle size of particles (μm)
The volume average diameter measured by the centrifugal sedimentation method (using CAPA500 manufactured by Horiba, Ltd.) was defined as the average particle diameter.

(S) Heat seal strength (N / cm)
TESTER SANGYO. CO. Using a 7P-701S HEAT SEAL TESTER manufactured by LTD, two heat-sealing resin layers are stacked on each other and heat-sealed under the conditions of a temperature of 120 ° C., a pressure of 0.1 MPa, and a pressing time of 1 sec. The sample was sampled at 15 mm, and the strength at the time of peeling at a peeling speed of 200 mm / min and a peeling angle of 90 ° was obtained using Toyo Baldwin Tensilon. The measurement was performed five times for each sample, and the average value thereof was defined as the heat seal strength.

(C) Surface wetting tension (mN / m)
It was measured according to JIS K 6768 (1999).

(G) Young's modulus, F2 value, F5 value in the longitudinal direction The Young's modulus, F2 value, and F5 value at 25 ° C. were measured using a film strength and elongation measuring device (AMF / RTA-100) manufactured by Orientec Co., Ltd. And measured at 65% RH. A sample is cut out to a size of 15 cm in a measurement direction, a direction perpendicular to the measurement direction: 1 cm, and is stretched at an original length of 50 mm and a pulling speed of 300 mm / min. The Young's modulus is based on JIS K 7127 (1999) / 2/300. It was measured (unit: GPa). For the F2 value and the F5 value, stress applied to the sample with respect to elongation of 2% and 5% was measured (unit: MPa). When the measurement was performed at a high temperature such as 80 ° C., a high and low temperature constant temperature bath manufactured by Gondoux Science Co., Ltd. was attached, and the measurement was performed under the same conditions as described above.

(S) Heat shrinkage (%)
The film is sampled at a test length of 260 mm and a width of 10 mm from the film with the measurement direction as the longitudinal direction and the width direction, and a mark is placed at a position of 200 mm as the original size (L0). A load of 3 g is applied to the lower end of the sample, heat-treated in a hot air circulating oven at 120 ° C. for 15 minutes, taken out at room temperature, and the length (L1) marked on the sample is measured. At this time, the heat shrinkage is obtained by the following equation. The above operation was performed in each direction (length direction and width direction), and the sum of the heat shrinkage in the length direction and the width direction was obtained.

Heat shrinkage (%) = 100 × (L0−L1) / L0
(V) Water Vapor Permeability A single biaxially stretched polypropylene film was measured at a temperature of 40 ° C. and a humidity of 90% RH using a water vapor permeability measuring device PERMATRAN-W3 / 30 manufactured by MOCON / Modern Controls. The measurement was performed 5 times for each sample, the obtained value was converted to a value per unit thickness (0.1 μm), the average value thereof was calculated, and the average value was defined as the water vapor transmission rate of the biaxially stretched polypropylene film alone. (Unit: g / m ² /d/0.1 mm). For the metal-deposited biaxially stretched polypropylene film, a polypropylene adhesive film (3M Scotchmark, 40 μm thickness) is applied to the metal-deposited surface (the surface on the overcoat layer if an overcoat layer is provided). The measurement was performed under the conditions described above. The measurement was performed five times for each sample, the average value of the obtained values was calculated, and the average value was defined as the water vapor transmission rate of the metal-deposited biaxially stretched polypropylene film (unit: g / m ² / d).

(H) Oxygen Permeability A pressure-sensitive adhesive film made of polypropylene (Scotchmark, manufactured by 3M) is provided on the surface of the metal-deposited biaxially stretched polypropylene film on which metal deposition has been performed (the surface on the overcoat layer when an overcoat layer is provided). (With a thickness of 40 μm), and the measurement was carried out using an oxygen transmittance measuring device Oxtran 2/20 manufactured by MOCON / Modern Controls at a temperature of 23 ° C. and a humidity of 0% RH. The measurement was performed five times for each sample, and the average value of the obtained values was calculated and defined as the water vapor transmission rate of the film (unit: ml / m ² / d / MPa).

(T) Surface gloss of metal-deposited film A metal-deposited biaxially-stretched polypropylene film is loaded into a vacuum deposition device, aluminum is evaporated from an electron beam heating type evaporation source, and the optical film manufactured by Macbeth Co. Aluminum was deposited in an optical density (-log (light transmittance)) of 2.0 to 2.5 measured using a densitometer (TR927). The metal-deposited surface of this metal-deposited film was measured for 60 ° specular glossiness based on JIS Z8741 (1997), and was defined as surface glossiness (unit:%).

(T) Effective stretch ratio An unstretched film extruded from a slit-shaped die, wound around a metal drum, and cooled and solidified on a sheet is placed on a square with a length of 1 cm and each side is parallel to the longitudinal direction and width direction of the film. After being stamped so as to be stretched and wound up, the length (cm) of the square of the obtained film was measured, and this was defined as the effective stretching ratio in the longitudinal direction and the lateral direction.

(G) Film thickness (μm)
It measured using the dial gauge type thickness gauge based on JISK7130 (1999).

(D) Secondary workability An unstretched polypropylene film having a thickness of 20 μm is dry-laminated on one surface of a biaxially stretched polypropylene film having a length of 1000 m and a thickness of 15 μm for use in the present invention using a polyurethane-based adhesive. For the metal-deposited biaxially stretched polypropylene film, a 15 μm-thick biaxially-stretched polypropylene film is deposited on the metal-deposited surface (the surface on the overcoat layer when an overcoat layer is provided) and on the opposite surface. A 20 μm unstretched polypropylene film was dry-laminated using a polyurethane-based adhesive to obtain a food packaging film composed of polypropylene. The film was inserted into a cylindrical shape using a vertical pillow wrapping machine (FUJI FW-77) manufactured by Fujiki Kai Co., Ltd. so that the unstretched polypropylene film layer was on the inside, and the bag was formed.

  At that time, if the film does not have wrinkles or elongation, and the shape of the bag-making product is good, it is marked as ○, and the film has low Young's modulus in the longitudinal direction or low waist, stretches, slips poorly, heat shrinks Due to the large ratio, the shape of the bag-made product deteriorates due to wrinkles, and cracks are generated in the metal layer of the metallized film on the whole surface when the bag-made product is observed with an optical microscope. Were evaluated as x.

(D) Changes in gas barrier properties due to secondary processing In (na) above, changes in water vapor permeability and oxygen permeability before and after bag making are measured in accordance with (ta) and (h) above, and gas barrier properties before and after bag making are measured. The gas barrier property deterioration rate during the secondary processing was evaluated based on the change in the properties. That is, when both the water vapor transmission rate and the oxygen transmission rate deterioration rate defined by the following formulas were less than 100%, it was evaluated as ○, and when either of them deteriorated by 100% or more, it was evaluated as x. In this evaluation, those of ○ were considered to be acceptable.

  Deterioration rate (%) = ([Transmittance after secondary processing]-[Transmittance before secondary processing]) / [Transmittance before secondary processing] × 100.

  The present invention will be described based on examples. In order to obtain a film having a desired thickness, the rotation speed of the extruder and the peripheral speed of the cooling drum were adjusted to predetermined values unless otherwise specified. Unless otherwise specified, surface treatment of the film, coating of the coating layer, and metal deposition were performed on the surface in contact with the cooling drum when producing an unstretched sheet in the process of producing the film.

  First, a biaxially stretched polypropylene film used for the base layer of the present invention was prepared as in Reference Examples 1 to 5 below. In addition, polypropylene films that cannot be applied to the base layer of the present invention were prepared as in Reference Examples 6 to 8 below.

(Reference Example 1)
A known polypropylene having a melt tension (MS) of 1.5 cN, a melt flow rate (MFR) of 2.3 g / 10 min, a mesopentad fraction (mmmm) of 92%, and an isotactic index (II) of 96%. , MS is 20 cN, MFR is 3 g / 10 min, mmmm is 97%, II is 96.5%, and high melt tension polypropylene having a long chain branch satisfying the relationship between MS and MFR in the formula (1) ( HMS-PP) is added at a ratio of 5% by weight and mixed with 97% by weight of polypropylene. As an additive which is compatible with polypropylene and has a plasticizing effect at the time of stretching, a petroleum resin substantially free of polar groups 100 parts by weight of a resin obtained by adding and mixing 3% by weight of polydicyclopentadiene having a Tg of 80 ° C., a bromine number of 3 cg / g, and a hydrogenation rate of 99% to form crosslinked organic particles. 0.15 parts by weight of crosslinked particles of a polymethacrylic acid polymer (crosslinked PMMA) having an average particle size of 2 μm are added, and the mixture is supplied to a twin-screw extruder, extruded at 270 ° C. in a gut shape, and passed through a 20 ° C. water bath. After cooling and cutting to a length of 3 mm with a chip cutter, the chips dried at 100 ° C. for 2 hours are fed to a single screw extruder, melted at 270 ° C., extruded from a slit die after passing through a filtration filter, and heated at 25 ° C. It was wound around a drum and formed into a sheet.

  The sheet is preheated by passing through a roll kept at 135 ° C., passed between rolls having a peripheral speed difference kept at 140 ° C., stretched 8 times in the longitudinal direction, and immediately cooled to room temperature. Subsequently, the stretched film was introduced into a tenter and preheated at 165 ° C., stretched 8 times in the width direction at 160 ° C., and then heat-set at 160 ° C. while giving 6% relaxation in the width direction, followed by cooling. To give a biaxially stretched polypropylene film having a thickness of 15 μm.

  Tables 1 and 2 summarize the raw material composition of the obtained film and the evaluation results of the film characteristics. The resulting film had a high Young's modulus in the longitudinal direction, was excellent in tensile strength, and was excellent in dimensional stability, moisture resistance and secondary workability.

(Reference Example 2)
In Reference Example 1, a terpene substantially free of a polar group is used as an additive which has a mixing ratio of HMS-PP having a long-chain branching of 10% by weight and is compatible with polypropylene to have a plasticizing effect at the time of stretching. 0.15 weight of crosslinked silicon particles having an average particle size of 2 μm instead of crosslinked PMMA particles in a resin composition of 5% by weight of β-pinene having a Tg of 75 ° C., a bromine value of 4 cg / g and a hydrogenation rate of 99% A 15-μm-thick biaxially-stretched polypropylene film produced under the same conditions except that the film was stretched 9 times in the longitudinal direction and 7 times in the width direction was used as Reference Example 2.

  The results are shown in Tables 1 and 2. The resulting film had a high Young's modulus in the longitudinal direction, was excellent in tensile strength, and was excellent in dimensional stability, moisture resistance and secondary workability.

(Reference Example 3)
In Reference Example 1, the same except that the mixing ratio of HMS-PP having a long chain branch was 10% by weight, the addition amount of polydicyclopentadiene was 10% by weight, and the film was stretched 10 times in the longitudinal direction and 6 times in the width direction. A 15 μm-thick biaxially oriented polypropylene film produced under the above conditions was used as Reference Example 3.

  The results are shown in Tables 1 and 2. The resulting film had a high Young's modulus in the longitudinal direction, was excellent in tensile strength, and was excellent in dimensional stability, moisture resistance and secondary workability.

(Reference Example 4)
In Reference Example 1, the melt tension (MS) was 1.1 cN, the melt flow rate (MFR) was 3 g / 10 min, the mesopentad fraction (mmmm) was 97.5%, and the isotactic index (II) was 99%. Produced under the same conditions except that 10% by weight of polydicyclopentadiene is added to 90% by weight of polypropylene obtained by adding 10% by weight of HMS-PP to a known polypropylene and stretched 9 times in the longitudinal direction and 9 times in the width direction. The obtained biaxially oriented polypropylene film having a thickness of 15 μm was used as Reference Example 4.

  The results are shown in Tables 1 and 2. The resulting film had a high Young's modulus in the longitudinal direction, was excellent in tensile strength, and was excellent in dimensional stability, moisture resistance and secondary workability.

(Reference Example 5)
A resin in which crosslinked PMMA particles were not added to the resin composition used in Reference Example 1 was used as a base layer resin, and 100% by weight of an ethylene / propylene random copolymer having an ethylene content of 1% by weight was used as a resin for forming a deposited film easy-adhesion resin layer. Using a resin composition obtained by adding 0.1 parts by weight of crosslinked PMMA particles having an average particle size of 2 μm to the vapor-deposited film easy-adhesion resin layer, supplying them to separate extruders, passing through a filtration filter, and then biaxially stretching. Are joined in a two-layer laminated die and extruded from a slit-shaped die so that the thickness of the vapor-deposited film easy-adhesive resin layer / base layer becomes 1/14 μm, and the metal drum is heated at 30 ° C. so that the surface of the easy-adhesive resin layer is in contact with the metal drum. A 15 μm-thick laminated biaxially stretched polypropylene film produced by biaxially stretching the unstretched sheet produced by winding under the same conditions as in Reference Example 1 was used as Reference Example 5.

  The results are shown in Tables 1 and 2. The resulting film had a high Young's modulus in the longitudinal direction, was excellent in tensile strength, and was excellent in dimensional stability, moisture resistance and secondary workability.

(Reference Example 6)
The melt tension (MS) is 1.5 cN, the melt flow rate (MFR) is 2.3 g / 10 min, the mesopentad fraction (mmmm) is 92%, and the isotactic index (II) is 96%. (2) Crosslinked particles of a polymethacrylic acid polymer having an average particle size of 2 μm as crosslinked organic particles in 100 parts by weight of a known polypropylene alone, which does not satisfy the relational expression between the melt tension (MS) and the melt flow rate (MFR). 0.15 parts by weight of (cross-linked PMMA) was fed to a single screw extruder, melted at 270 ° C, extruded from a slit die after passing through a filtration filter, wound around a 25 ° C metal drum and formed into a sheet. did.

  The sheet is preheated by passing through a roll maintained at 130 ° C., passed between rolls having a peripheral speed difference maintained at 135 ° C., stretched 5 times in the longitudinal direction, and immediately cooled to room temperature. Subsequently, the stretched film is introduced into a tenter, preheated at 165 ° C., stretched 10 times in the width direction at 160 ° C., and then heat-set at 160 ° C. while giving 7% relaxation in the width direction, and then cooled. Then, a 15 μm-thick biaxially stretched polypropylene film was obtained.

  The results are shown in Tables 1 and 2. The obtained film had a low Young's modulus in the longitudinal direction, insufficient tensile strength, and was inferior in moisture-proof property and secondary workability.

(Reference Example 7)
In Reference Example 6, as an additive which is compatible with polypropylene in 97% by weight of polypropylene alone and has a plasticizing effect at the time of stretching, it is a petroleum resin substantially free of a polar group, Tg 80 ° C., bromine value A 15 μm thick biaxially stretched polypropylene film produced under the same conditions except that 3 cg / g, 3% by weight of polydicyclopentadiene having a hydrogenation rate of 99% were mixed and stretched 5 times in the longitudinal direction and 9 times in the width direction. Was referred to as Reference Example 7.

  The results are shown in Tables 1 and 2. The resulting film had a low Young's modulus in the longitudinal direction, insufficient tensile strength, and poor secondary workability.

(Reference Example 8)
In Reference Example 7, a biaxially oriented polypropylene film having a thickness of 15 μm was produced under the same conditions except that the addition amount of polydicyclopentadiene was changed to 10% by weight.

  The results are shown in Tables 1 and 2. The resulting film had a low Young's modulus in the longitudinal direction at 80 ° C., had insufficient tensile strength, and was poor in dimensional stability and secondary workability.

（実施例１）
参考例１において、二軸延伸後、引き続き片面に炭酸ガス濃度１５％、窒素ガス濃度８５％の雰囲気中でコロナ放電処理を行い、表面濡れ張力を４５ｍＮ／ｍとして二軸延伸ポリプロピレンフィルムを得た。

(Example 1)
In Reference Example 1, after biaxial stretching, a corona discharge treatment was continuously performed on one surface in an atmosphere having a carbon dioxide gas concentration of 15% and a nitrogen gas concentration of 85% to obtain a biaxially stretched polypropylene film with a surface wetting tension of 45 mN / m. .

  Next, the biaxially stretched polypropylene film is put into a vacuum evaporator and run, and the heat-melted and evaporated aluminum metal is aggregated and deposited to a thickness of 45 nm on the corona discharge treated surface, and a metal evaporation layer is provided. A vapor-deposited biaxially oriented polypropylene film was obtained.

The gas barrier properties of the metal-deposited biaxially oriented polypropylene film were as follows: oxygen permeability: 180 ml / m ² / d / MPa; water vapor permeability: 0.18 g / m ² / d. In addition, no noticeable crack was observed in the metal deposited layer after the secondary processing, and there was no significant change in gas barrier performance.

(Example 2)
In Reference Example 2, a metal-deposited biaxially stretched polypropylene film was obtained in the same manner as in Example 1.

The gas barrier properties of the metal-deposited biaxially oriented polypropylene film were an oxygen permeability of 150 ml / m ² / d / MPa and a water vapor permeability of 0.14 g / m ² / d. In addition, no noticeable crack was observed in the metal deposited layer after the secondary processing, and there was no significant change in gas barrier performance.

(Example 3)
In Reference Example 3, a metal-deposited biaxially stretched polypropylene film was obtained in the same manner as in Example 1.

The gas barrier performance of the metal-deposited biaxially stretched polypropylene film was an oxygen permeability of 120 ml / m ² / d / MPa and a water vapor permeability of 0.11 g / m ² / d. In addition, no noticeable crack was observed in the metal deposited layer after the secondary processing, and there was no significant change in gas barrier performance.

(Example 4)
In Reference Example 4, a metal-deposited biaxially stretched polypropylene film was obtained in the same manner as in Example 1.

Gas barrier performance of the metal-deposited biaxially stretched polypropylene film was as follows: oxygen permeability: 90 ml / m ² / d / MPa; water vapor permeability: 0.09 g / m ² / d. In addition, no noticeable crack was observed in the metal deposited layer after the secondary processing, and there was no significant change in gas barrier performance.

(Example 5)
In Reference Example 5, corona discharge treatment and metal vapor deposition were performed on the surface of the deposited film easily adhesive resin layer in the same manner as in Example 1 to obtain a metal vapor-deposited biaxially stretched polypropylene film.

The gas barrier performance of the metal-deposited biaxially oriented polypropylene film was an oxygen permeability of 110 ml / m ² / d / MPa and a water vapor permeability of 0.12 g / m ² / d. In addition, no noticeable crack was observed in the metal deposited layer after the secondary processing, and there was no significant change in gas barrier performance.

(Comparative Example 1)
In Reference Example 6, a metal-deposited biaxially stretched polypropylene film was obtained in the same manner as in Example 1.

The gas barrier performance of the metal-deposited biaxially oriented polypropylene film was such that the oxygen permeability was 300 ml / m ² / d / MPa and the water vapor permeability was 0.25 g / m ² / d. The metal-deposited biaxially-stretched polypropylene film has a low Young's modulus in the longitudinal direction, has insufficient tensile strength and is inferior in secondary workability, so dry lamination, after the bag making process, the film shows elongation and wrinkles. In addition, numerous streak-like cracks occurred in the metal deposition layer. For this reason, the gas barrier performance after the secondary processing was significantly deteriorated.

(Comparative Example 2)
In Reference Example 8, a metal-deposited biaxially stretched polypropylene film was obtained in the same manner as in Example 1.

The gas barrier performance of the metal-deposited biaxially oriented polypropylene film was 270 ml / m ² / d / MPa for oxygen permeability and 0.22 g / m ² / d for water vapor permeability. The metal-deposited biaxially oriented polypropylene film has a low Young's modulus at a high temperature (80 ° C.), has insufficient tensile strength, and is poor in secondary workability. And countless streak-like cracks occurred in the metal deposition layer. For this reason, the gas barrier performance after the secondary processing was significantly deteriorated.

(Example 6)
In Reference Example 1, the surface of the film stretched 8 times in the longitudinal direction was subjected to corona discharge treatment in the air to a wet tension of 37 mN / m, and a polyester urethane-based water-dispersible resin as a coating layer was formed on the treated surface. Hydran "AP-40F (manufactured by Dainippon Ink and Chemicals, Inc., solid content: 30%), 100 parts by weight of N-methylpyrrolidone as a water-soluble organic solvent, and 15 parts by weight of melamine as a crosslinking agent 5 parts by weight of compound "Beckamine" APM (manufactured by Dainippon Ink and Chemicals, Inc.) was added, and "Catalyst" PTS (manufactured by Dainippon Ink and Chemicals, Inc.), a water-soluble acidic compound, was further added as a crosslinking accelerator. 2 parts by weight of the mixed coating agent was coated with a coating bar and stretched 8 times in the width direction in the same manner as in Reference Example 1 to obtain a biaxially stretched polypropylene film. . The thickness configuration of the film was: coating layer / core layer = 0.2 μm / 15 μm.

  Next, the biaxially stretched polypropylene film is put into a vacuum evaporation apparatus and run, and the aluminum metal evaporated by heating and melting is cohered and deposited to a thickness of 45 nm on the surface of the coating layer. A vapor-deposited biaxially oriented polypropylene film was obtained.

Regarding the gas barrier performance of the metal-deposited biaxially stretched polypropylene film, the oxygen permeability was 20 ml / m ² / d / MPa, and the water vapor permeability was 0.07 g / m ² / d. In addition, no noticeable crack was observed in the metal deposited layer after the secondary processing, and there was no significant change in gas barrier performance.

(Example 7)
In Example 6, 100 parts by weight of “Hydran” AP-40F (manufactured by Dainippon Ink and Chemicals, Inc., solid content concentration: 30%) as a polyester urethane-based water-dispersible resin of a coating layer, and a melamine compound as a crosslinking agent 5 parts by weight of Becamine “APM” (manufactured by Dainippon Ink and Chemicals, Inc.) and 2 parts by weight of a water-soluble acidic compound “Catalyst” PTS (manufactured by Dainippon Ink and Chemicals, Inc.) as a crosslinking accelerator Example 7 was a metal-evaporated biaxially stretched polypropylene film produced in the same manner except that the mixed coating agent added in part was coated with a coating bar.

Regarding the gas barrier performance of the metal-deposited biaxially stretched polypropylene film, the oxygen permeability was 30 ml / m ² / d / MPa, and the water vapor permeability was 0.08 g / m ² / d. In addition, no noticeable crack was observed in the metal deposited layer after the secondary processing, and there was no significant change in gas barrier performance.

(Example 8)
The surface layer of the biaxially stretched polypropylene film obtained in Reference Example 3 was subjected to corona discharge treatment in the air to a wet tension of 37 mN / m, and the mixed coating composition of Example 6 was applied as a coating layer on the treated surface offline. The film was coated with a gravure coater, dried with hot air at 110 ° C., formed into a coating layer having a thickness of 0.2 μm, wound up, and subjected to aluminum vapor deposition in the same manner as in Example 6 to obtain a metal-deposited biaxially stretched polypropylene film as Example 8. .

Regarding the gas barrier performance of the metal-deposited biaxially stretched polypropylene film, the oxygen permeability was 9 ml / m ² / d / MPa, and the water vapor permeability was 0.06 g / m ² / d. In addition, no noticeable crack was observed in the metal deposited layer after the secondary processing, and there was no significant change in gas barrier performance.

(Example 9)
In Reference Example 4, a metal-evaporated biaxially stretched polypropylene film produced in the same manner as in Example 6 was used as Reference Example 9.

The gas barrier properties of the metal-deposited biaxially oriented polypropylene film were such that the oxygen permeability was 7 ml / m ² / d / MPa and the water vapor permeability was 0.04 g / m ² / d. In addition, no noticeable crack was observed in the metal deposition layer after the secondary workability, and there was no significant change in gas barrier performance.

(Example 10)
In Reference Example 5, a metal-deposited biaxially stretched polypropylene film produced by performing corona discharge, coating layer coating, and metal deposition on the surface of the deposited film easily adhesive resin layer in the same manner as in Example 6 was used as Example 10.

The gas barrier performance of the metal-deposited biaxially oriented polypropylene film was such that the oxygen permeability was 10 ml / m ² / d / MPa and the water vapor permeability was 0.06 g / m ² / d. In addition, no noticeable crack was observed in the metal deposited layer after the secondary processing, and there was no significant change in gas barrier performance.

(Comparative Example 3)
In Reference Example 1, 0.12 mol of terephthalic acid, 0.84 mol of isophthalic acid, 0.33 mol of diethylene glycol, and 0.65 mol of neopentyl glycol were distilled out at 190 to 220 ° C. under the presence of a catalyst. The reaction was carried out for 6 hours while removing water, followed by a condensation reaction at 250 ° C. under reduced pressure for 1 hour to obtain a prepolymer, and then 5- (2,5-dioxotetrahydrofurfuryl) -3-methyl-3 0.13 mol of -cyclohexene 1,2-dicarboxylic anhydride was charged and subjected to selective monoesterification reaction at 140 ° C for 3 hours to obtain a polymer. Further, this polymer was neutralized with ammonia to obtain a polyester resin. Next, 10 parts by weight of a hexamethylene diisocyanate of an isocyanate compound is added as a crosslinking agent per 100 parts by weight of the active ingredient of the polyester resin, and “Catalyst” PTS (Dai Nippon Ink Chemical Industry Co., Ltd. Comparative Example 3 was made of a metal-deposited biaxially stretched polypropylene film produced in the same manner as in Example 6, except that a coating agent prepared by adding 1.5 parts by weight of) was used.

The gas barrier performance of the metal-deposited biaxially stretched polypropylene film was an oxygen permeability of 120 ml / m ² / d / MPa and a water vapor permeability of 0.1 g / m ² / d. The metal-deposited biaxially stretched polypropylene film has a low adhesive strength between the base film and the coating layer (the adhesive strength of the metal-deposited layer cannot be measured), and the coating layer is peeled off from the film after dry lamination and bag making. The appearance of the bag product deteriorated, and the gas barrier performance also deteriorated significantly.

(Comparative Examples 4 and 5)
In Example 6, metal-deposited biaxially oriented polypropylene produced under the same conditions except that the thickness of the coating layer formed on the corona discharge treated surface of the biaxially oriented polypropylene film of Reference Example 1 was changed to 0.03 μm and 4 μm The films were Example 4 and Example 5, respectively.

In Comparative Example 4, the adhesion strength between the base film and the coating layer was low (because the coating layer could not be uniformly applied when the coating layer thickness was small and pinholes were formed in the metal deposition layer due to surface irregularities). The adhesive strength was not measurable), no gas barrier property improving effect was observed, and the gas barrier performance was 195 ml / m ² / d / MPa for oxygen permeability and 0.2 g / m ² / d for water vapor permeability. Further, after dry lamination and bag making, the coating layer was peeled off from the film, and the appearance of the bag-made product was deteriorated, and the gas barrier performance was greatly deteriorated.

In Comparative Example 5, since the coating layer was thick, the curing of the coating layer was insufficient, the wound film was blocked, and the adhesive strength with the film surface layer was low (therefore, the adhesive strength of the metal deposition layer could not be measured). The gas barrier performance was also oxygen permeability 210 ml / m ² / d / MPa and water vapor permeability 0.3 g / m ² / d. In addition, the handleability at the time of dry lamination and bag making was poor, and after processing, the coating layer was peeled off from the film, the appearance of the bag-made product was deteriorated, and the gas barrier performance was greatly deteriorated.

(Comparative Example 6)
In Reference Example 6, a metal-deposited biaxially stretched polypropylene film was obtained in the same manner as in Example 6.

The gas barrier performance of the metal-deposited biaxially oriented polypropylene film was improved to 30 ml / m ² / d / MPa in oxygen permeability and 0.15 g / m ² / d in water vapor permeability due to the provision of the coating layer. However, since the metal-deposited biaxially stretched polypropylene film has a low Young's modulus in the longitudinal direction, insufficient tensile strength, and poor secondary workability, the film does not show any elongation or wrinkles after dry lamination and bag making. In addition, numerous streak-like cracks occurred in the metal deposition layer. For this reason, the gas barrier performance after the secondary processing was significantly deteriorated.

(Comparative Example 7)
In Reference Example 7, a metal-deposited biaxially stretched polypropylene film was obtained in the same manner as in Example 6.

The gas barrier performance of the metal-deposited biaxially stretched polypropylene film was improved to 27 ml / m ² / d / MPa in oxygen permeability and 0.10 g / m ² / d in water vapor permeability due to the provision of the coating layer. However, since the metal-deposited biaxially stretched polypropylene film has a low Young's modulus in the longitudinal direction, has insufficient tensile strength and is inferior in secondary workability, dry lamination and elongation and wrinkling are observed after the bag making process. At the same time, numerous streak-like cracks occurred in the metal deposition layer. For this reason, the gas barrier performance after the secondary processing was significantly deteriorated.

(Example 11)
The same coating agent as used in Example 6 was applied to the metal-deposited layer of the metal-deposited biaxially stretched polypropylene film obtained in Example 5 using an off-line gravure coater, dried with hot air at 110 ° C., and dried. Example 11 A metal-deposited biaxially stretched polypropylene film formed and wound with an overcoat layer made of a 0.5 μm polyester urethane resin was used as Example 11.

As for the gas barrier performance of the metal-deposited biaxially oriented polypropylene film, the oxygen permeability was 95 ml / m ² / d / MPa, and the water vapor permeability was 0.10 g / m ² / d
Met. In addition, no noticeable crack was observed in the metal deposition layer after the secondary processing, and there was no significant change in gas barrier performance.

(Example 12)
In Example 11, a metal-deposited biaxially-stretched polypropylene film was formed in the same manner as in Example 10, except that the metal-deposited biaxially-stretched polypropylene film obtained in Example 10 was replaced with a metal-deposited biaxially-stretched polypropylene film. Example 12 was made of a biaxially stretched polypropylene film.

The metal-deposited biaxially stretched polypropylene film has a gas barrier performance of oxygen permeability of 7 ml / m ² / d / MPa and water vapor permeability of 0.05 g / m ² / d
Met. In addition, no noticeable crack was observed in the metal deposited layer after the secondary processing, and there was no significant change in gas barrier performance.

(Comparative Example 8)
In the same manner as in Example 11, except that the metal-deposited biaxially-stretched polypropylene film used in Example 11 was changed to the metal-deposited biaxially-stretched polypropylene film obtained in Comparative Example 1, a metal having an overcoat layer formed of a polyester urethane resin was formed. A vapor deposited biaxially oriented polypropylene film was used as Comparative Example 8.

The metal-deposited biaxially stretched polypropylene film has a gas barrier performance of oxygen permeability of 200 ml / m ² / d / MPa and water vapor permeability of 0.18 g / m ² / d
Met. Since the metal-deposited biaxially stretched polypropylene film forms an overcoat layer, deterioration of gas barrier performance after secondary processing can be suppressed to some extent, but Young's modulus in the longitudinal direction is low, and tensile strength is insufficient. After dry lamination and bag making, the film showed elongation and wrinkles, and innumerable streak-like cracks occurred in the metal deposited layer. For this reason, the gas barrier performance after the secondary processing deteriorated.

(Comparative Example 9)
In Example 11, a metal-deposited biaxially-stretched polypropylene film was formed in the same manner as in Example 11, except that the metal-deposited biaxially-stretched polypropylene film obtained in Comparative Example 6 was replaced with the metal-deposited biaxially-stretched polypropylene film. A biaxially stretched polypropylene film was used as Comparative Example 9.

Regarding the gas barrier performance of the metal-deposited biaxially stretched polypropylene film, the oxygen permeability was 22 ml / m ² / d / MPa, and the water vapor permeability was 0.12 g / m ² / d. Since the metal-deposited biaxially stretched polypropylene film forms an overcoat layer, deterioration of gas barrier performance after secondary processing can be suppressed to some extent, but Young's modulus in the longitudinal direction is low, and tensile strength is insufficient. After dry lamination and bag making, the film showed elongation and wrinkles, and innumerable streak-like cracks occurred in the metal deposited layer. For this reason, the gas barrier performance after the secondary processing deteriorated.

得られた金属蒸着二軸延伸ポリプロピレンフィルムの評価結果をまとめて表３に示す。表３より、本発明の金属蒸着二軸延伸ポリプロピレンフィルムは、長手方向の剛性が高く、二次加工後も蒸着層に膜割れ（クラック）が発生しにくいため、ガスバリア性能の悪化を抑制することができる。また、基層の原料構成（ポリプロピレンの結晶性（ｍｍｍｍ、ＩＩなど）、添加剤処方など）や、基層フィルムに蒸着膜易接着樹脂を積層したり、基層と蒸着層の間に特定の被覆層を設け、その被覆厚みや基層フィルムとの接着強度を制御することにより、さらにガスバリア性能を高めることができた。その上、金属蒸着層上にオーバーコート層を形成することにより、二次加工後のガスバリア性能の悪化をさらに抑制することができた。また、このような優れた金属蒸着二軸延伸ポリプロピレンフィルムおよびそれに用いる二軸延伸ポリプロピレンフィルムを工業的に安定に製造することができた。

Table 3 summarizes the evaluation results of the obtained metal-deposited biaxially oriented polypropylene films. As shown in Table 3, the metal-deposited biaxially stretched polypropylene film of the present invention has high rigidity in the longitudinal direction and does not easily cause film cracks in the deposited layer even after the secondary processing. Can be. Also, the raw material composition of the base layer (crystallinity of polypropylene (mmmm, II, etc.), additive formulation, etc.), lamination of a deposition film easy-adhesion resin on the base layer film, and formation of a specific coating layer between the base layer and the deposition layer The gas barrier performance could be further enhanced by controlling the thickness of the coating and the adhesive strength with the base layer film. In addition, by forming the overcoat layer on the metal deposition layer, it was possible to further suppress the deterioration of the gas barrier performance after the secondary processing. In addition, such an excellent metal-deposited biaxially oriented polypropylene film and a biaxially oriented polypropylene film used for the same could be produced industrially stably.

  The metal-deposited biaxially stretched polypropylene film of the present invention has excellent gas barrier performance, and since the deterioration of the gas barrier performance after the secondary processing is suppressed, the conventional metal-deposited biaxially stretched polypropylene film-based metal-deposited film has It can be widely applied to a wide range of applications such as packaging applications and industrial applications, including fields where gas barrier properties deteriorate due to too low rigidity and could not be applied.

Claims (7)

The relationship between the melt tension (MS) and the melt flow rate (MFR) measured at 230 ° C. is expressed by the following equation (1).
log (MS)>-0.61 log (MFR) +0.82 (1)
Containing a polypropylene that satisfies, and compatible with the polypropylene, at least one surface of a base layer made of a biaxially stretched polypropylene film in which one or more additives capable of having a plasticizing effect at the time of stretching are mixed, a metal deposition layer is provided. A metal-deposited biaxially stretched polypropylene film, which is installed. The relationship between the melt tension (MS) and the melt flow rate (MFR) measured at 230 ° C. is expressed by the following equation (2).
log (MS)>-0.61 log (MFR) +0.52 (2)
A metal vapor-deposited layer is provided on at least one surface of a base layer made of a biaxially stretched polypropylene film in which at least one kind of additive that is compatible with polypropylene and has a plasticizing effect at the time of stretching is mixed. A biaxially oriented metallized polypropylene film. The metal-deposited biaxially stretched polypropylene film according to claim 1 or 2, wherein the metal-deposited layer has an adhesive strength of 0.3 N / cm or more. 4. The biaxial metal-deposited biaxial according to claim 1, wherein a coating layer made of a polyester urethane resin having a thickness of 0.05 to 2 [mu] m is provided between the base layer and the metal-deposited layer. Stretched polypropylene film. The metal-deposited biaxially stretched polypropylene film according to any one of claims 1 to 4, wherein the additive is a petroleum resin substantially free of a polar group and / or a terpene resin substantially free of a polar group. The metal-deposited biaxially stretched polypropylene film according to any one of claims 1 to 5, wherein the polypropylene has a mesopentad fraction (mmmm) in the range of 90 to 99.5%. The metal-deposited biaxially stretched polypropylene film according to any one of claims 1 to 6, wherein an overcoat layer is provided on the metal-deposited layer.