TW201815586A - Laminated polypropylene film - Google Patents

Abstract

Provided is a laminated polypropylene film that has a gas barrier performance comparable to polyvinylidene chloride-coated polypropylene films, and comprises: a film that uses a propylene polymer; and a thin-film layer having an inorganic compound as the main component thereof. The laminated polypropylene film comprises: a polypropylene film base that uses a polypropylene resin; and a thin-film layer having an inorganic compound as the main component thereof, and the laminated polypropylene film is characterized by having a longitudinal heat shrinkage ratio at 150 DEG C of not more than 7%, and having an oxygen permeability of not more than 150 mL/m2/day/MPa.

Description

   Laminated polypropylene film and laminated body   

The present invention relates to a laminated polypropylene film including a film using a polypropylene resin and a film layer containing an inorganic compound as a main component. More specifically, the present invention relates to a laminated polypropylene film which is excellent in gas barrier properties and can be suitably used in various fields requiring dimensional stability and high rigidity at high temperatures.

In the past, polypropylene stretch films have been widely used in a wide range of applications such as packaging for food and various products, electrical insulation, and surface protection films due to their excellent flexibility and moisture resistance.

However, for food applications, oxygen barrier properties are often required for films due to preservation of food. In the past, laminated films based on vapor deposition of inorganic compounds on polypropylene films had insufficient oxygen barrier properties. A film formed by coating and drying a solution of an oxygen-barrier resin such as polyvinylidene chloride.

However, since there are steps of coating and drying the solution in which the oxygen-barrier resin is dissolved, there is a limit in terms of reducing production costs, and it is necessary to set the oxygen-barrier resin layer to a thickness of about 5 μm, and the layering step is expensive. Increased time or cost of raw materials.

Furthermore, there is also a problem that the thickness of the film after lamination is large, and it is difficult to perform printing, sealing, or bag-making processing.

Therefore, a laminated film obtained by vapor-depositing an inorganic compound film on a polypropylene film is desired to have excellent oxygen barrier properties, but a laminated film obtained by directly vapor-depositing an inorganic compound on a polypropylene film cannot obtain gas barrier properties (for example, refer to Patent Document 1) , Patent Document 2).

[Prior technical literature]

[Patent Literature]

Patent Document 1: Japanese Patent Application Laid-Open No. 11-105190.

Patent Document 2: Japanese Patent Application Laid-Open No. 2000-355068.

This invention is made | formed based on the subject of the said prior art. That is, an object of the present invention is to provide a laminated polypropylene film which has the same gas barrier properties as a polypropylene-based film coated with polyvinylidene chloride and is provided with a polypropylene-based resin. The polypropylene film substrate and the thin film layer containing an inorganic compound as a main component have low cost and excellent processability.

The present inventors conducted diligent research in order to achieve the above object, and as a result, completed the present invention. That is, the laminated polypropylene film of the present invention includes a polypropylene film substrate using a polypropylene resin and a thin film layer containing an inorganic compound as a main component; and a thermal shrinkage rate of 150 ° C in the longitudinal direction in the laminated polypropylene film. It is 7% or less, and the oxygen permeability is 150 mL / m ² / day / MPa or less.

The conventional laminated polypropylene film has a shrinkage rate of 9% or more at 150 ° C in the longitudinal direction. It is estimated that the polypropylene film substrate has thermal energy from vapor deposition particles during evaporation of inorganic compounds to the polypropylene film substrate or comes from the storage. Shrinkage of the crucible of an inorganic compound causes shrinkage, and the influence of the shrinkage causes a change in the gas barrier property of the inorganic compound layer itself to decrease.

In this case, the haze of the laminated polypropylene film is preferably 6% or less.

In this case, it is preferable that the thermal shrinkage ratio in the transverse direction of 150 ° C. in the laminated polypropylene film is 7% or less.

In this case, a laminated body containing the aforementioned laminated polypropylene film and polyolefin film is preferred.

The laminated polypropylene film according to the present invention can have oxygen barrier properties equivalent to those of a polypropylene-based film coated with polyvinylidene chloride, and can even be made into a thin film.

Furthermore, the laminated polypropylene film of the present invention can of course maintain the oxygen barrier property at normal temperature, and can maintain the oxygen barrier property and other various physical properties even when exposed to an environment of about 150 ° C, so it can also be used where conventional polypropylene The film can be used in a wide range of applications because it cannot be imagined in the case of oxygen barrier properties or high temperature environments.

For example, by using the laminated polypropylene film of the present invention as a base material layer and laminating a heat sealing layer on the surface of the base material layer, it can be applied to various packaging forms that require heat sealability. When the laminated film of the laminated polypropylene film is heat-sealed, since the heat-sealing temperature can be set high and the heat-sealing strength is improved, the production line speed in bag-making processing can be increased, and productivity can be improved. It can also be used as a substrate for extrusion lamination with large heat load.

In addition, even when a high-temperature treatment such as retort is performed after bag making, the amount of deformation of the bag can be suppressed.

FIG. 1 is a graph for explaining the azimuth dependence and the full width at half maximum of the refractive power of the 110-type crystal of the α-type crystal in the wide-angle X-ray refraction pattern of the polypropylene film used as the base material of the laminated polypropylene film. .

The present invention relates to a laminated polypropylene film with excellent gas barrier properties, dimensional stability at high temperatures, and mechanical properties.

The laminated polypropylene film of the present invention is provided with a polypropylene film substrate using a polypropylene resin and a thin film layer containing an inorganic compound as a main component; in the laminated polypropylene film, the thermal shrinkage rate in the longitudinal direction at 150 ° C is 7% Hereinafter, the oxygen permeability is 150 mL / m ² / day / MPa or less.

[Inorganic thin film layer]

The inorganic thin film layer used in the present invention has an inorganic compound as a main component, and the inorganic compound is preferably an inorganic oxide. As the inorganic oxide, at least one of aluminum oxide and silicon oxide or a composite oxide of these is preferable.

The "main component" herein means that the total amount of aluminum oxide, silicon oxide, and the composite oxide of aluminum oxide and silicon oxide exceeds 50% by mass, preferably 70% by mass, with respect to 100% by mass of the constituents constituting the thin film layer. Above, more preferably 90% by mass or more, and most preferably 100% by mass (components other than alumina and silicon oxide are not included as components constituting the thin film layer).

The alumina mentioned here is composed of at least one or more of various aluminum oxides such as AlO, Al ₂ O, and Al ₂ O _3. The content ratio of various aluminum oxides can be adjusted according to the production conditions of the thin film layer. The so-called silicon oxide is composed of at least one or more kinds of various silicon oxides such as SiO, SiO ₂ , and Si ₃ O _2. The content ratio of various silicon oxides can be adjusted according to the production conditions of the thin film layer. The so-called composite oxide of aluminum oxide and silicon oxide is composed of AlxSiy (x = 1 to 2, y = 1 to 3), and the content ratio of various silicon oxides can be adjusted by the production conditions of the thin film layer. For aluminum oxide, silicon oxide, and composite oxides of aluminum oxide and silicon oxide, other components may be contained in the component in a range that does not impair the characteristics (up to 3% relative to the total component).

Examples of components other than the "main component" include compounds such as titanium oxide, magnesium oxide, zirconia, cerium oxide, and zinc oxide, and mixtures thereof.

The thickness of the inorganic thin film layer is not particularly limited. In terms of gas barrier properties and flexibility, it is preferably 5 nm to 500 nm, more preferably 10 nm to 200 nm, and still more preferably 15 nm to 50 nm. If the thickness of the thin film layer is less than 5 nm, it may be difficult to obtain satisfactory gas barrier properties; on the other hand, even if it exceeds 500 nm, the corresponding effect of improving the gas barrier properties cannot be obtained, and the resistance to bending Or it becomes disadvantageous in terms of manufacturing costs.

[Laminated polypropylene film]

The laminated polypropylene film of the present invention has characteristics especially in terms of physical properties of the laminated film. The laminated polypropylene film of the present invention exhibits the following film properties. In addition, the following physical properties are measured and evaluated by the method described in Examples below.

(Heat shrinkage)

The laminated polypropylene film of the present invention is an stretched film mainly composed of a polypropylene resin, and the thermal shrinkage ratio in the longitudinal direction at 150 ° C must be 7% or less. Here, the so-called longitudinal direction of the film (sometimes also referred to as the length direction or the long-side direction), and the so-called transverse direction are perpendicular to the direction of the film (sometimes also referred to as the lateral direction or the width direction). The conventional laminated polypropylene film has a thermal shrinkage rate of 9% or more at 150 ° C in the longitudinal direction.

The upper limit of the 150 ° C thermal shrinkage of the laminated polypropylene film of the present invention in the longitudinal direction is preferably 6%, more preferably 5%, and even more preferably 4%. If the upper limit of the thermal contraction rate at 150 ° C in the longitudinal direction is within the above range, the gas barrier properties will be better.

When an inorganic compound is vapor-deposited on a polypropylene film substrate, although a film using a propylene-based polymer shrinks due to thermal energy possessed by the inorganic compound molecules used for the vapor deposition material or radiant heat from a crucible containing the inorganic compound, it is estimated If the degree of shrinkage of the polypropylene film substrate is small when the inorganic thin film layer is formed, it is difficult for gas to pass through. As a reason, it is considered that if shrinkage of the polypropylene film base material occurs during the formation of the inorganic thin film layer, the inorganic thin film layer is destroyed due to the bulge of the surface of the base material, or it is difficult to form a dense inorganic thin film layer.

The lower limit of the 150 ° C thermal shrinkage in the longitudinal direction is preferably 0.2%, more preferably 0.3%, still more preferably 0.5%, even more preferably 0.7%, and most preferably 1.0%. If the lower limit of the 150 ° C. thermal contraction rate in the longitudinal direction is within the above range, realistic manufacturing may be facilitated in terms of cost and the like, or thickness unevenness may be reduced.

The upper limit of the 150 ° C thermal shrinkage rate in the transverse direction of the laminated polypropylene film of the present invention is preferably 7%, more preferably 6%, still more preferably 5%, and even more preferably 4%. If the upper limit of the 150 ° C heat shrinkage rate in the horizontal direction is within the above range, when the laminated polypropylene film or the laminated film using the laminated polypropylene film is further heat-sealed, the heat-sealing temperature is set to be high. , And then the strength (heat seal strength) is increased, so the production line speed in bag making processing can be increased, and the productivity is improved. Furthermore, even when a high-temperature process such as cooking is performed after the bag is made, the amount of deformation of the bag can be suppressed.

The lower limit of the 150 ° C thermal contraction rate in the horizontal direction is preferably 0.2%, more preferably 0.3%, still more preferably 0.5%, particularly preferably 0.7%, and most preferably 1.0%. If the lower limit of the 150 ° C. thermal contraction rate in the horizontal direction is within the above range, realistic manufacturing may be facilitated in terms of cost and the like, or thickness unevenness may be reduced.

(Oxygen Transmission)

In the present invention, the upper limit of the oxygen permeability of the laminated polypropylene film at a temperature of 23 ° C. and a relative humidity of 65% must be 150 mL / m ² / day / MPa or less. It is more preferably 130 mL / m ² / day / MPa or less, still more preferably 120 mL / m ² / day / MPa or less, still more preferably 100 mL / m ² / day / MPa or less, and even more preferably 90 mL / m ² / day. / MPa or less. When the upper limit of the oxygen permeability exceeds 150 mL / m ² / day / MPa, the storage property of a substance or food deteriorated by oxygen becomes poor. The lower limit of the oxygen permeability of the laminated polypropylene film at a temperature of 23 ° C. and a humidity of 65% is not particularly limited, but is preferably 0.1 mL / m ² / day / MPa or more. In addition, from the viewpoint of manufacturing, 0.1 mL / m ² / day / MPa is considered to be the lower limit.

(Haze)

The upper limit of the haze of the laminated polypropylene film of the present invention is preferably 6%, more preferably 5%, still more preferably 4.5%, even more preferably 4%, and even more preferably 3.5%. When the upper limit of the haze is the above range, it may be easily used in applications requiring transparency. In order to set the haze to 6% or less, the inorganic thin film layer is preferably transparent.

Regarding the lower limit of the haze of the laminated polypropylene film of the present invention, in terms of realistic values, it is preferably 0.1%, more preferably 0.2%, still more preferably 0.3%, and even more preferably 0.4%.

(Polypropylene film substrate)

The polypropylene film base material used in the laminated polypropylene film of the present invention has characteristics especially in terms of film physical properties. The stretched polypropylene film of the present invention exhibits the following film properties. In addition, each physical property below is set to the value measured and evaluated by the method described later in an Example, for example.

(Heat shrinkage)

The polypropylene film substrate used in the present invention is an stretched film composed mainly of a polypropylene-based resin, and the upper limit of the thermal contraction rate in the longitudinal direction at 150 ° C is preferably 10%, more preferably 9%, and It is more preferably 7%, and even more preferably 5%. The conventional polypropylene film has a thermal shrinkage at a temperature of 150 ° C in the longitudinal direction of 11% or more. By setting the thermal shrinkage of the polypropylene film substrate to 10% or less, the thermal shrinkage of the laminated polypropylene film of the present invention in the longitudinal direction at 150 ° C can be set to 7% or less.

In addition, the polypropylene film base material used in the present invention is an stretched film composed mainly of a polypropylene resin, and the heat shrinkage rate in the transverse direction at 150 ° C is preferably 15% or less, more preferably 9%, and It is more preferably 7%, and even more preferably 7% or less. The conventional polypropylene film has a thermal shrinkage rate of 16% or higher at 150 ° C in the transverse direction. By setting the thermal shrinkage of the polypropylene film substrate to 10% or less, it is possible to set the thermal shrinkage of the laminated polypropylene film of the present invention at 150 ° C in the transverse direction to 7% or less.

Here, the longitudinal direction refers to the direction of travel of the film (sometimes referred to as the length direction), and the so-called lateral direction refers to the direction perpendicular to the direction of travel of the film (also sometimes referred to as the width direction).

The lower limit of the 150 ° C thermal shrinkage of the longitudinal direction and the transverse direction of the polypropylene film substrate used in the present invention is preferably 0.2%, more preferably 0.3%, still more preferably 0.5%, particularly preferably 0.7%. It is preferably 1.0%. When the thermal shrinkage rate at 150 ° C is in the above range, realistic manufacturing may be facilitated in terms of cost and the like, or thickness unevenness may be reduced.

In addition, if the thermal shrinkage rate at 150 ° C is not less than about 1.5%, it can be achieved by, for example, increasing the low molecular weight component of polypropylene in the film substrate and adjusting the film's stretching conditions or heat setting conditions. 1.5% or less, preferably an off-line annealing treatment or the like.

(Haze)

Regarding the lower limit of the haze of the polypropylene film substrate used in the present invention, in terms of realistic values, it is preferably 0.1%, more preferably 0.2%, still more preferably 0.3%, and even more preferably 0.4%. The upper limit of the haze is preferably 6%, more preferably 5%, still more preferably 4.5%, even more preferably 4%, and most preferably 3.5%. When the haze is within the above range, it may be easily used in applications requiring transparency. For example, when the stretching temperature and heat-fixing temperature are too high, when the CR (Chill Roll) temperature is high, and the cooling speed of the stretching roll sheet is slow, and when the low molecular weight is too high, the haze may be The tendency to worsen can be controlled within the aforementioned range by adjusting these factors.

(Thickness)

The lower limit of the thickness of the polypropylene film substrate used in the present invention is 3 μm, preferably 4 μm, and more preferably 8 μm.

If the lower limit of the thickness of the film is less than 3 μm, the laminated polypropylene film is easily curled, and the gas barrier property is easily reduced.

From the viewpoint of the processability of the film thickness, the upper limit is preferably 300 μm, more preferably 250 μm, still more preferably 200 μm, still more preferably 150 μm, even more preferably 100 μm, and most preferably 50 μm.

(Impact resistance)

The lower limit of the impact resistance (23 ° C) of the polypropylene film substrate used in the present invention is preferably 0.6J, more preferably 0.7J. When the impact resistance is within the above range, it has sufficient toughness as a film and does not break during handling. In practical terms, the upper limit of impact resistance is preferably 2J, more preferably 1.8J, still more preferably 1.6J, and even more preferably 1.5J. For example, when there are many low molecular weight components of polypropylene in the film substrate, when the overall molecular weight is low, when there are few high molecular weight components of polypropylene in the film substrate, and when the molecular weight of the high molecular weight components is high. In a low case, the impact resistance tends to decrease, so the impact resistance can be controlled within the aforementioned range by adjusting these factors according to the application.

(Young's rate)

In the case where the polypropylene film substrate used in the present invention is a biaxially stretched film, the lower limit of the Young's rate (23 ° C) in the longitudinal direction is preferably 2 GPa, more preferably 2.1 GPa, and even more preferably 2.2 GPa. Particularly preferred is 2.3 GPa, and most preferred is 2.4 GPa. The upper limit of the Young's ratio in the longitudinal direction is preferably 4 GPa, more preferably 3.7 GPa, still more preferably 3.5 GPa, even more preferably 3.4 GPa, and most preferably 3.3 GPa. When the Young's ratio in the vertical direction is in the above range, practical production may be easy, and the vertical-horizontal balance may be improved.

When the polypropylene film used for the substrate of the present invention is a biaxially stretched film, the lower limit of the Young's rate (23 ° C) in the lateral direction is preferably 3.8 GPa, more preferably 4 GPa, and still more preferably 4.1 GPa. , Especially preferably 4.2GPa. The upper limit of the Young's rate in the horizontal direction is preferably 8 GPa, more preferably 7.5 GPa, still more preferably 7 GPa, and even more preferably 6.5 GPa. If the Young's ratio in the horizontal direction is in the above range, practical production may be easy, and the balance between the Young's ratio in the vertical direction and the horizontal direction may be good. In addition, the Young's ratio in the vertical and horizontal directions can be increased, for example, by increasing the stretching ratio in each direction. In the case of extending in the horizontal direction after extending in the vertical direction, the vertical stretching ratio can be set to If it is low, set the horizontal magnification to high, etc., and increase the Young's ratio in the horizontal direction.

(Thickness uniformity)

The lower limit of the uniformity of the thickness of the polypropylene film substrate used in the present invention is preferably 0%, more preferably 0.1%, still more preferably 0.5%, and even more preferably 1%. The upper limit of the thickness uniformity is preferably 20%, more preferably 17%, still more preferably 15%, even more preferably 12%, and most preferably 10%. When the uniformity of the thickness is within the above range, defects are less likely to occur during post-processing such as coating or printing, and it is easy to use for applications requiring precision.

(Film density)

The lower limit of the present invention is used in the density of the polypropylene film substrate is preferably 0.910g / cm ^3, more preferably 0.911g / cm ^3, and more preferably 0.912g / cm ^3, particularly preferably 0.913g / cm ³ . When the film density is in the above range, the crystallinity may be high and the heat shrinkage rate may be reduced. The upper limit of the film density is preferably 0.930g / cm ^3, more preferably 0.928g / cm ^3, and more preferably 0.926g / cm ^3, particularly preferably 0.925g / cm ^3. When the film density exceeds the above-mentioned upper limit, production may become difficult in reality. The film density can be increased by increasing the stretching ratio or temperature, increasing the heat-fixing temperature, and further performing off-line annealing.

(Refractive index)

The lower limit of the refractive index (Nx) in the longitudinal direction of the polypropylene film substrate used in the present invention is preferably 1.502, more preferably 1.503, and even more preferably 1.504. The upper limit of Nx is preferably 1.520, more preferably 1.517, and even more preferably 1.515.

The lower limit of the refractive index (Ny) in the transverse direction of the polypropylene film substrate used in the present invention is preferably 1.523, more preferably 1.525. The upper limit of Ny is preferably 1.535, more preferably 1.532.

The lower limit of the refractive index (Nz) in the thickness direction of the polypropylene film substrate used in the present invention is preferably 1.480, more preferably 1.489, and even more preferably 1.500. The upper limit of Nz is preferably 1.510, more preferably 1.507, and even more preferably 1.505.

(Face alignment coefficient)

The lower limit of the surface alignment coefficient of the polypropylene film used in the substrate of the present invention is preferably 0.0125, more preferably 0.0126, still more preferably 0.0127, and even more preferably 0.0128. Regarding the upper limit of the surface alignment coefficient, in terms of realistic values, it is preferably 0.0155, more preferably 0.0150, still more preferably 0.0148, and even more preferably 0.0145. The surface alignment coefficient can be set within a range by adjusting the extension magnification. When the surface alignment coefficient is within this range, the thickness unevenness of the film tends to be good.

(Film orientation)

Polypropylene film substrates usually have crystalline alignment, and the direction or degree of the crystalline alignment greatly affects the physical properties of the film. The degree of crystalline alignment varies depending on the molecular structure of the polypropylene used or the process or conditions in the manufacture of the film. In addition, the orientation direction of the stretched polypropylene film can be determined by the following method: X-rays are incident perpendicularly to the film surface by a wide-angle X-ray refraction method, and the azimuth dependency of the scattering peaks derived from crystals is measured. In detail, the stretched polypropylene film typically has a monoclinic α-type crystal structure. In addition, for the α-type crystal, if the azimuth dependence of the scattering intensity of the 110 plane (plane interval: 6.65 angstroms) is measured by a wide-angle X-ray refraction method, it has a strong alignment mainly in a uniaxial direction. That is, when the scattering intensity derived from the 110 plane of the α-type crystal is plotted with respect to the azimuth angle, the strongest wave peak is observed in the vertical direction of the alignment of the molecular axis. In the present invention, the degree of alignment is specified by the full width at half maximum of the maximum wave crest.

In addition, a typical pattern is shown in FIG. 1 about the azimuth dependence of the scattering from the 110 plane of the α-type crystal of polypropylene. In addition, FIG. 1 shows the full width at half maximum of the main peaks (maximum peaks, azimuth angles of 180 ° and 360 °) of the azimuth dependence of the 110 plane.

For the polypropylene film used in the base material of the present invention, it is preferable that the maximum width at half maximum of the peak width when the scattering intensity of 110 planes measured by the wide-angle X-ray scattering method with respect to the azimuth angle is 30 degrees the following. The upper limit of the FWHM is more preferably 29 degrees, and even more preferably 28 degrees. If the full width at half maximum of the azimuth dependence of the scattering intensity from the 110 plane is larger than the aforementioned range, the alignment is insufficient, and the heat resistance or rigidity is insufficient. The lower limit of the azimuth dependence of the scattering intensity from the 110 plane is preferably 5 degrees, more preferably 7 degrees, and even more preferably 8 degrees. If the full width at half maximum of the 110 plane is smaller than the aforementioned range, a reduction in impact resistance or a disordered alignment may occur.

(Wide-angle X-ray refraction device)

The predetermined full width at half maximum is preferably measured using X-rays having high parallelism, and radiation light is preferably used.

As an X-ray generation source for wide-angle X-ray refraction measurement, a general device such as a tube type or a rotary type used in a laboratory may be used, but it is preferable to use a device capable of irradiating radiation with high parallelism and high brightness. High brightness light source. Among the emitted light, X-rays are easy to expand and have high brightness, so they can be measured with high accuracy and in a short time. For example, even for a film sample with a thickness of several tens of microns, a film can be measured without overlapping the films. Since high-precision measurement is performed, detailed crystal orientation evaluation can be performed. On the other hand, for low-brightness X-rays, when measuring film samples with a thickness of several tens of micrometers, there is the following tendency: if multiple pieces are not overlapped, the measurement takes a long time; if multiple pieces are overlapped, then The peak width when the scattering intensity of the 110 plane is plotted with respect to the azimuth angle due to a slight shift is widened, and the value of the FWHM obtained is increased.

Examples of equipment that can irradiate radiation with high parallelism and high brightness include, for example, large-scale radiation facilities such as SPring-8. For example, the FSBL (Frontier Softmaterial Beamline; Advanced Materials Development Industry-Academic Consortium) Beamline BL03XU measures the full width at half maximum of the present invention.

(Long-period structure, SAXS (Small-Angle X-ray Scattering))

The polypropylene film substrate used in the present invention preferably has a long period and a large size. Generally, a crystalline polymer has a regular multilayer structure (periodic structure) composed of repetition of crystalline and amorphous. Here, the size of a repeating unit composed of a crystal and an amorphous is referred to as a long period size. This long-period size can be obtained from the scattering peak angle, which is derived from the long-period structure of the main alignment direction measured by the small-angle X-ray scattering method.

It is preferable that the long-period scattering peaks obtained from the small-angle X-ray scattering measurement of the polypropylene film used in the substrate of the present invention are clearly observed in the main alignment direction. The so-called main alignment direction is a direction in which a scattering caused by a long period of a polymer crystal is more strongly observed in a two-dimensional X-ray scattering pattern. In the case of uniaxial extension, the main alignment direction is consistent with the extension direction in most cases. In the case of successive biaxial extension in the longitudinal extension-horizontal extension, although it depends on each extension magnification, in most cases the main orientation The direction is the same as the horizontal extension direction. The more obvious the observation of long-period peaks caused by polymer crystallization is, the longer-period structure with higher order is formed.

The polypropylene film used in the substrate of the present invention preferably has a long period size of 40 nm or more obtained from a long period scattering peak. The lower limit of the long period size is more preferably 41 nm, and even more preferably 43 nm. If the long-period dimension is smaller than the aforementioned range, the melting peak temperature is low, and thus the heat resistance tends to be lowered. The upper limit of the long period size is preferably 100 nm, more preferably 90 nm, and even more preferably 80 nm. If the long-period size is larger than the aforementioned range, it takes a long time for crystallization or heat treatment, so that realistic manufacturing tends to be difficult.

(Small angle X-ray refraction device)

As an X-ray generation source for small-angle X-ray scattering measurement, there is no particular limitation, and a general device such as a tube type or a rotary type used in a laboratory may be used. As the X-ray generation source, a high-brightness light source capable of radiating high-brightness radiated light is used. Especially in the case where the polypropylene film substrate used in the present invention has a large long period, the X-ray scattering originating from the long period structure is located in a region with a smaller angle side. Therefore, it is difficult to measure in the case of a laboratory X-ray device with a large X-ray beam diameter and short shooting length. Therefore, it is preferable to use X-rays that are not easy to expand, and the beam diameter can be controlled below several hundred microns, and the brightness is also For high-emission light, the ultra-small-angle area is measured with a long shooting length. At this time, the shooting length is preferably 7 m or more.

[Polypropylene resin]

The polypropylene-based resin used for the polypropylene film substrate of the present invention is not particularly limited. For example, a propylene homopolymer or a copolymer with ethylene and / or an α-olefin having 4 or more carbon atoms, and a mixture thereof can be used.

The polypropylene resin constituting the film is preferably a propylene homopolymer that does not substantially contain a comonomer, and even when a comonomer is contained, the comonomer amount is preferably 0.5 mol% or less. The upper limit of the comonomer amount is preferably 0.3 mole%, and even more preferably 0.1 mole%. If it is the said range, crystallinity may improve and the heat shrinkage rate at high temperatures may become small. Furthermore, a small amount of comonomer may be contained within a range that does not significantly reduce crystallinity.

The polypropylene-based resin constituting the film is preferably a propylene homopolymer obtained only from a propylene monomer, and even if it is a propylene homopolymer, it is also preferable that it does not contain a head-to-head bond heterogeneous bond.

(Three-dimensional regularity of polypropylene resin)

The lower limit of the meso pentad component ratio measured by ¹³ C-NMR (Nuclear Magnetic Resonance; nuclear magnetic resonance) as an index of the stereoregularity of the polypropylene resin constituting the film is preferably 96%. The lower limit of the meso pentad component ratio is preferably 96.5%, more preferably 97%. If it is the said range, crystallinity may improve and the thermal shrinkage rate at the time of high temperature may fall further. The upper limit of the meso pentad component ratio is preferably 99.8%, more preferably 99.6%, and still more preferably 99.5%. If it is the said range, realistic manufacture may become easy.

The lower limit of the meso average chain length of the polypropylene resin constituting the film is preferably 100, more preferably 120, and even more preferably 130. If it is the said range, crystallinity may improve and the heat shrinkage rate at high temperatures may become small. For practical purposes, the upper limit of the meso average chain length is preferably 5,000.

In practical terms, the lower limit of the xylene soluble content of the polypropylene resin constituting the film is preferably 0.1% by mass. The upper limit of the xylene-soluble component is preferably 7 mass%, more preferably 6 mass%, and still more preferably 5 mass%. If it is the said range, crystallinity may improve and the heat shrinkage rate at high temperatures may become small.

(Mel flow rate of polypropylene resin)

The lower limit of the MFR (Melt Flow Rate) (230 ° C, 2.16 kgf) of the polypropylene resin is 0.5 g / 10 minutes. The lower limit of MFR is preferably 1.0 g / 10 minutes, more preferably 1.3 g / 10 minutes, still more preferably 1.5 g / 10 minutes, even more preferably 2.0 g / 10 minutes, and even more preferably 4.0 g / 10 minutes. It is preferably 6.0 g / 10 minutes. If it is the said range, there may be a small mechanical load, and extrusion or extension may become easy. The upper limit of MFR is 20 g / 10 minutes, preferably 17 g / 10 minutes, more preferably 16 g / 10 minutes, and even more preferably 15 g / 10 minutes. If it is in the said range, extending | stretching may become easy, thickness unevenness may become small, or it may become easy to raise an extending | stretching temperature or a heat setting temperature, and a thermal shrinkage rate may fall further.

(Molecular weight of polypropylene resin)

The lower limit of the number average molecular weight (Mn) measured by GPC (Gel Permeation Chromatography) of the polypropylene resin constituting the film is preferably 20,000, more preferably 22,000, and even more preferably 24,000, especially The best is 26000, and the best is 27000. If it is in the said range, there exists a merit that it becomes easy to extend | stretch, thickness unevenness becomes small, and it is easy to raise elongation temperature or heat-fixing temperature, and a heat shrinkage rate will fall. The upper limit of Mn is preferably 200,000, more preferably 170,000, still more preferably 160,000, and even more preferably 150,000. If it is the said range, the effect of this case, such as a low thermal shrinkage rate at high temperature, of a polypropylene film base material which is a low molecular weight substance of a polypropylene resin may become easy to obtain, or extension may become easy.

The lower limit of the mass average molecular weight (Mw) measured by GPC of the polypropylene resin constituting the film is preferably 180,000, more preferably 200,000, still more preferably 230,000, even more preferably 240,000, and even more preferably 250,000. It is 270,000. If it is in the said range, there exists a merit that it becomes easy to extend | stretch, thickness unevenness becomes small, and it is easy to raise elongation temperature or heat-fixing temperature, and a heat shrinkage rate will fall. The upper limit of Mw is preferably 500,000, more preferably 450,000, still more preferably 420,000, particularly preferably 410,000, and most preferably 400,000. If it is the said range, a mechanical load may become small and extrusion or extension may become easy.

(Molecular weight distribution of polypropylene resin)

The polypropylene-based resin used in the present invention preferably has the following characteristics. That is, when measuring the gel permeation chromatography (GPC) cumulative curve of the polypropylene resin constituting the film, the lower limit of the amount of the component having a molecular weight of 100,000 or less is preferably 35% by mass, and more preferably 38%. Mass%, more preferably 40% by mass, particularly preferably 41% by mass, and most preferably 42% by mass. If it is the said range, the effect of this case, such as a low thermal shrinkage rate at the time of high temperature which is the effect of a low molecular weight substance, may become easy to obtain, or it may become easy to extend. The upper limit of the amount of components with a molecular weight of 100,000 or less in the GPC cumulative curve is preferably 65% by mass, more preferably 60% by mass, still more preferably 58% by mass, particularly preferably 56% by mass, and most preferably 55% by mass . If it exists in the said range, extending | stretching may become easy, thickness unevenness may become small, or it may become easy to raise extending | stretching temperature or heat-fixing temperature, and thermal contraction rate may fall.

For the polypropylene resin used in the present invention, the lower limit of the mass average molecular weight (Mw) / number average molecular weight (Mn) as an index of the breadth of the molecular weight distribution is preferably 4, more preferably 4.5, and even more preferably 5, particularly preferably 5.5, and most preferably 6. The upper limit of Mw / Mn is preferably 30, more preferably 25, still more preferably 22, particularly preferably 21, and most preferably 20. When Mw / Mn is in the above range, practical production is easy.

Moreover, the molecular weight distribution of polypropylene can be adjusted by: using a series of equipment to polymerize components of different molecular weights in multiple stages; or blending components of different molecular weights by using a kneader in an offline manner; or blending with different properties Polymerization of catalyst; or use of catalyst that can achieve the desired molecular weight distribution.

(Manufacturing method of polypropylene resin)

The polypropylene resin can be obtained by polymerizing propylene as a raw material using a known catalyst such as a Ziegler-Natta catalyst or a metallocene catalyst. Among them, in order to eliminate heterogeneous bonds, it is preferable to use a catalyst capable of polymerizing with high stereoregularity among Ziegler-Natta catalysts.

As the polymerization method of propylene, any known method may be adopted, and examples thereof include a method of polymerization in an inactive solvent such as hexane, heptane, toluene, xylene, and the like; and a method of polymerization in a liquid monomer. ; A method of adding a catalyst to a monomer of a gas to perform polymerization in a gas phase state; or a method of combining these methods to perform polymerization.

(Additive)

To the polypropylene film substrate used in the present invention, additives or other resins may be added as needed. Examples of the additives include antioxidants, ultraviolet absorbers, antistatic agents, lubricants, nucleating agents, adhesives, antifog agents, flame retardants, antiblocking agents, and inorganic or organic fillers. Examples of other resins include polypropylene resins other than the polypropylene resin used in the present invention, random copolymers as copolymers of propylene and ethylene and / or α-olefins having 4 or more carbon atoms, or various elastomers. Wait. These components can be polymerized successively using a multi-stage reactor, or blended with a polypropylene resin using a Henschel mixer, or the mother particles prepared by using a melt kneader in advance can be diluted with polypropylene to a predetermined concentration. Alternatively, the entire amount may be melt-kneaded before use.

(Manufacturing method of stretched polypropylene film)

The polypropylene film used as the substrate of the present invention may be a uniaxially stretched film in a longitudinal direction (long side direction) or a transverse direction (width direction), and preferably a biaxially stretched film. In the case of biaxial extension, it may be sequential biaxial extension or simultaneous biaxial extension.

Hereinafter, as a best example, a method for manufacturing a sequential biaxially stretched film that is stretched in the longitudinal direction to the transverse direction will be described.

First, a polypropylene resin is heated and melted by a uniaxial or biaxial extruder, and extruded onto a cooling roll to obtain an unstretched sheet. As the conditions for melt extrusion, the resin was extruded from a T-die in the form of a sheet so that the resin temperature became 200 ° C to 280 ° C, and was cooled and solidified using a cooling roll at a temperature of 10 ° C to 100 ° C. Then, the film is stretched in the length (longitudinal) direction by 3 to 8 times, preferably 3 to 7 times, using a stretching roller at 120 ° C to 165 ° C, and then 155 ° C to 175 ° C, preferably The temperature of 158 ° C to 170 ° C is extended from 4 to 20 times, preferably from 6 to 12 times. Next, heat treatment is performed while relaxing at a temperature of 1% to 15% at an ambient temperature of 165 ° C to 175 ° C, preferably 166 ° C to 173 ° C. The polypropylene film thus obtained can be rolled up by a winder after being subjected to a corona discharge treatment at least on one side as required, thereby obtaining a roll sample.

The lower limit of the stretch magnification in the longitudinal direction is preferably 3 times, and more preferably 3.5 times. When the stretching ratio in the longitudinal direction is smaller than the above value, the film thickness may become uneven. The upper limit of the stretching ratio in the longitudinal direction is preferably 8 times, more preferably 7 times. If the stretching ratio in the longitudinal direction exceeds the above-mentioned value, the subsequent lateral stretching may become difficult in some cases.

The lower limit of the elongation temperature in the longitudinal direction is preferably 120 ° C, more preferably 125 ° C, and still more preferably 130 ° C. If the stretching temperature in the longitudinal direction is less than the above-mentioned value, the mechanical load may increase, the thickness unevenness may increase, or the surface of the film may be roughened. The upper limit of the elongation temperature in the longitudinal direction is preferably 165 ° C, more preferably 160 ° C, still more preferably 155 ° C, and even more preferably 150 ° C. When the elongation temperature is high, it is preferable to reduce the heat shrinkage rate. However, it may adhere to the roll and fail to extend, or cause rough surface.

The lower limit of the transverse magnification is preferably 4 times, more preferably 5 times, and even more preferably 6 times. If the stretching ratio in the horizontal direction is smaller than the above value, the thickness may become uneven. The upper limit of the lateral magnification is preferably 20 times, more preferably 17 times, still more preferably 15 times, and even more preferably 12 times. If the stretching ratio in the horizontal direction exceeds the above value, the thermal shrinkage ratio may increase or the film may break during stretching.

Regarding the preheating temperature in the transverse direction stretching, in order to rapidly increase the film temperature to around the stretching temperature, it is preferably set to be 5 ° C to 15 ° C higher than the stretching temperature.

The stretching in the lateral direction is preferably performed at a temperature of 3 ° C to 5 ° C higher than that of a conventional stretched polypropylene film. The lower limit of the extension temperature of TD (Transverse Direction) is preferably 155 ° C, more preferably 157 ° C, and even more preferably 158 ° C. If the elongation temperature in the lateral direction is less than the above-mentioned value, it may not be sufficiently softened and fractured, or the thermal shrinkage rate may be increased. The upper limit of the lateral extension temperature is preferably 175 ° C, more preferably 170 ° C, and even more preferably 168 ° C. In order to reduce the thermal shrinkage rate, the elongation temperature in the lateral direction is preferably high. However, if the value exceeds the above value, not only the low-molecular-weight component may be melted and recrystallized to reduce the orientation, but also the surface may be roughened or the film may be whitened.

The stretched film is usually heat fixed. In the present invention, heat fixing can be performed at a temperature of 3 ° C to 10 ° C higher than that of the conventional stretched polypropylene film. The lower limit of the heat-fixing temperature is preferably 165 ° C, and more preferably 166 ° C. When the heat-fixing temperature is lower than the above-mentioned value, the thermal shrinkage rate may increase. In addition, in order to reduce the heat shrinkage rate, a long-term treatment is required, and productivity is poor. The upper limit of the heat-fixing temperature is preferably 175 ° C, and more preferably 173 ° C. When the heat-fixing temperature exceeds the above-mentioned value, the low-molecular-weight component may be melted and recrystallized to cause rough surface or whitening of the film.

It is preferable to perform relaxation (relaxation) during heat fixing. The lower relaxation limit is preferably 1%, more preferably 2%, and even more preferably 3%. If the slack is less than the above value, the thermal shrinkage rate may increase. The upper limit of the slack is preferably 10%, more preferably 8%. If the slack exceeds the above value, thickness unevenness may increase.

In addition, in order to reduce the thermal shrinkage, the film manufactured by the above steps may be temporarily rolled into a roll shape, and then annealed in an offline manner. The lower limit of the off-line annealing temperature is preferably 160 ° C, more preferably 162 ° C, and even more preferably 163 ° C. If the off-line annealing temperature is lower than the above value, the effect of annealing may sometimes not be obtained. The upper limit of the offline annealing temperature is preferably 175 ° C, more preferably 174 ° C, and even more preferably 173 ° C. When the off-line annealing temperature exceeds the above-mentioned value, transparency may decrease or thickness unevenness may increase.

The lower limit of the offline annealing time is preferably 0.1 minutes, more preferably 0.5 minutes, and even more preferably 1 minute. If the off-line annealing time is shorter than the above value, sometimes the effect of annealing cannot be obtained. The upper limit of the offline annealing time is preferably 30 minutes, more preferably 25 minutes, and even more preferably 20 minutes. If the off-line annealing time exceeds the above value, productivity may be reduced.

In addition, if the thermal shrinkage rate at 150 ° C is not less than about 1.5%, it can be achieved by, for example, adding a low molecular weight component and adjusting the elongation conditions or heat-fixing conditions. However, in order to reduce the temperature to 1.5% or less, an offline method is preferred. An annealing process is performed.

For example, when the elongation temperature and heat fixing temperature are too high, when the cooling roll (CR) temperature is high and the cooling speed of the stretched roll sheet is slow, and when the low molecular weight is too high, the haze may be deteriorated. Tendency, it can be controlled within the aforementioned range by adjusting these factors.

The stretched polypropylene film thus obtained is generally formed into a film with a width of 2000 mm to 12000 mm and a length of about 1000 m to 50,000 m, and is wound into a roll shape. In addition, it is cut according to each use, and it is provided in the form of a slit roll with a width of 300 mm to 2000 mm and a length of about 500 m to 5000 m.

(Manufacturing method of inorganic thin film layer)

When producing an inorganic thin film layer, a PVD (Physical Vapor Deposition) method such as a vacuum vapor deposition method, a sputtering method, or an ion plating method (a physical vapor deposition method) or a CVD (Chemical Vapor Deposition; chemical gas) can be suitably used. A well-known production method such as a phase deposition) method (chemical vapor deposition method) is preferably a physical vapor deposition method, and more preferably a vacuum vapor deposition method. For example, in the vacuum evaporation method, a mixture of Al ₂ O ₃ and SiO ₂ or a mixture of Al and SiO ₂ can be used as a vapor deposition source material. As a heating method, resistance heating, high-frequency induction heating, and electron beam heating can be used. Wait. In addition, reactive vapor deposition may be used, in which oxygen, nitrogen, water vapor, or the like is introduced as a reactive gas, or methods such as ozone addition and ion assist are used. In addition, as long as the object of the present invention is not impaired, the production conditions may be changed by applying a bias voltage or the like to the film base material, or raising or lowering the temperature of the film base material or the like. The manufacturing methods other than the sputtering method and the CVD method are also the same.

At this time, a coating layer may be provided between the polypropylene film substrate and the inorganic thin film layer, or a coating layer may be provided on the inorganic thin film layer.

[Use]

The laminated polypropylene film of the present invention has excellent characteristics which have not existed in the past as described above.

When it is used as a packaging film, it can be used as a substitute for a polypropylene film coated with polyvinylidene chloride because of its excellent gas barrier properties. Not only that, it can be made thinner due to higher rigidity. Achieve cost reduction and weight reduction.

In addition, since the laminated polypropylene film of the present invention has high heat resistance, it can be subjected to high-temperature processing during coating or printing, which can realize production efficiency or use coating agents, inks, and laminating adhesives that have been difficult to use in the past. Wait.

Furthermore, the laminated polypropylene film of the present invention is not limited to packaging, and can also be used as an insulating film for capacitors or motors, or as a substrate film for a back sheet of a solar cell.

(Manufacturing method of laminated laminate)

A laminated body obtained by providing a polyolefin resin layer having heat-sealability on the laminated polypropylene film of the present invention can be used to produce food and beverage, medicine, lotion, shampoo, oil, toothpaste, adhesive, adhesive, etc Packing containers with excellent filling suitability and storage suitability for chemicals, cosmetics, and various other items.

As the polyolefin-based resin layer having heat-sealing properties, a film or sheet of a resin that can be melted and welded to each other by heat can be used. Specifically, for example, low-density polyethylene, medium-density polyethylene, and high-density Density polyethylene, linear (linear) low density polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ionic polymer resin, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl Acrylic copolymers, ethylene-methyl methacrylate copolymers, ethylene-propylene copolymers, methylpentene polymers, polybutene polymers, polyolefin resins such as polyethylene or polypropylene are treated with acrylic acid, methacrylic acid, Acid-modified polyolefin resin modified with unsaturated carboxylic acids such as maleic acid, maleic anhydride, fumaric acid, itaconic, polyvinyl acetate resin, poly (meth) acrylic resin, polyvinyl chloride Film or sheet of resin. A typical film or sheet is a linear (linear) low-density polyethylene or polypropylene.

The upper limit of the oxygen permeability in the laminated laminate at a temperature of 23 ° C. and a relative humidity of 65% is preferably 50 mL / m ² / day / MPa, more preferably 30 mL / m ² / day / MPa, and even more preferably 20 mL / m ² / day / MPa, particularly preferably 15 mL / m ² / day / MPa. When the upper limit of the oxygen permeability is 50 mL / m ² / day / MPa, a substance or food degraded by oxygen is excellent in storage stability. The lower limit of the oxygen permeability of the laminated polypropylene film at a temperature of 23 ° C. and a humidity of 65% is not particularly limited, but is preferably 0.1 mL / m ² / day / MPa. In addition, from the viewpoint of manufacturing, 0.1 mL / m ² / day / MPa is considered to be the lower limit.

The lower limit of the lamination strength in the longitudinal direction of the laminated laminate is preferably 1.1 N / 15 mm, more preferably 1.2 N / 15 mm, and still more preferably 1.1 N / 15 mm. When the lower limit of the lamination strength in the longitudinal direction is 1.1 N / 15 mm, the strength of the packaging container is excellent. The upper limit of the lamination strength in the longitudinal direction is not particularly limited, but is preferably 3.0 N / 15 mm. In terms of manufacturing, 3.0 N / 15 mm is considered to be the upper limit.

[Example]

Hereinafter, the present invention will be described in detail based on examples, but the present invention is not limited to the examples. The measurement method of the physical property in an Example is as follows.

(1) (stereoregularity)

The measurement of the meso pentad fraction ([mmmm]%) and the meso average chain length were performed using ¹³ C-NMR as follows.

The meso pentad fraction was calculated according to the method described in "Macromolecules" by Zambelli et al., Vol. 6, p. 925 (1973).

The meso average chain length was calculated according to the method described in "Polymer Sequence Distribution", Chapter 2 (1977) (Academic Press, New York) by J.C. Randall.

^{The 13} C-NMR measurement was performed using "AVANCE500" manufactured by BRUKER, and 200 mg of a sample was dissolved in a mixed solution of o: dichlorobenzene and deuterated benzene at a ratio of 8: 2 (volume ratio) at 135 ° C and performed at 110 ° C.

(2) Xylene soluble content (unit: mass%)

1 g of polypropylene sample was dissolved in 200 ml of boiling xylene and left to cool, and then recrystallized in a constant temperature water tank at 20 ° C for 1 hour. The ratio of the mass dissolved in the filtrate to the original sample amount was taken as the xylene soluble component. (quality%).

(3) Melt flow rate (MFR, unit: g / 10 minutes)

MFR is measured according to JIS (Japanese Industrial Standards) K7210-1: 2014 at a temperature of 230 ° C and a load of 2.16 kgf.

(4) Molecular weight and molecular weight distribution

The molecular weight and molecular weight distribution were determined based on monodisperse polystyrene standards using gel permeation chromatography (GPC). The measurement conditions such as column and solvent used in GPC measurement are as follows.

Vehicle: 1,2,4-trichlorobenzene.

Column: TSKgel GMHHR-H (20) HT × 3.

Flow: 1.0ml / min.

Detector: RI (Refractive Index) detector.

Measurement temperature: 140 ° C.

The number average molecular weight (Mn), the mass average molecular weight (Mw), and the Z + 1 average molecular weight (Mz + 1) are the number of molecules (Ni) of the molecular weight (Mi) at each dissolution position of the GPC curve obtained from the molecular weight calibration curve, respectively. It is defined by the following formula.

Number average molecular weight: Mn = Σ (Ni.Mi) / Σ Ni.

Mass average molecular weight: Mw = Σ (Ni.Mi ² ) / Σ (Ni.Mi).

Z + 1 average molecular weight: Mz + 1 = Σ (Ni.Mi ⁴ ) / Σ (Ni.Mi ³ ).

Molecular weight distribution: Mw / Mn.

The molecular weight at the peak position of the GPC curve is defined as Mp.

When the baseline is not clear, the baseline is set within the range from the high molecular weight side of the dissolution peak closest to the high molecular weight side of the dissolution peak of the standard substance to the lowest position of the hem.

(5) Wide-angle X-ray refraction

In the embodiment of the present invention, in the large radiation light facility SPring-8, in the second hatch of the Beam Line BL03XU owned by the Advanced Materials Development Industry-University Consortium (FSBL), the X-ray source direction and the film are used. The measurement film was set so that the angle formed by the surface became perpendicular, and WAXS (Wide-Angle X-ray Scattering) measurement was performed. The measurement conditions are shown below.

The X-ray wavelength is set to 0.1 nm, and the detector is an imaging plate (RIGAKU RAXIS VII) or a CCD (Charge-Coupled Device; Charge Coupled Device) camera (Hamamatsu) with an image intensifier. Photonics V7739P + ORCA R2) calculates transmittance based on the values of ion chambers placed before and after the sample. The obtained two-dimensional image was corrected for air scattering in consideration of dark current (dark noise) and transmittance. When measuring the shooting length, cerium oxide (CeO ₂ ) was used, and Fit2D (software made by European Synchrotron Radiation Facility [http://www.esrf.eu/computing/scientific/FIT2D/]) was used to calculate the azimuth of the (110) plane. distributed.

(6) Long period size obtained by small angle X-ray scattering method

In the large-scale radiation facility SPring-8, in the second compartment of the Beam Line BL03XU owned by the Advanced Materials Development Industry-University Consortium (FSBL), the longitudinal direction of the film is up and down, the lateral direction is left and right, and the X-ray source direction The measurement film is installed so that the angle formed by the film surface becomes perpendicular to the small angle X-ray (SAXS) measurement. The measurement conditions are shown below.

The X-ray wavelength was set to 0.2 nm, the imaging length was about 7.7 m, and a scattered image in the range of 0.01 to 0.5 (nm-1) of the scattering vector q was obtained using an imaging plate (RIGAKU R-AXIS VII) as a detector. Here, when θ is set to half of the scattering angle 2 θ, π is set to the circumference ratio, and λ is set to the wavelength of X-ray, the scattering vector q is calculated by the formula q = 4 π sin θ / λ. In the same manner as the WAXS measurement, the scattering image obtained is corrected for air scattering in consideration of dark current (dark noise) and transmittance. In order to determine an accurate shooting length, collagen that has been corrected by silver behenate is used. The aforementioned Fit2d software was used to calculate the distribution in the width direction of the sample. The horizontal axis was taken as the scattering vector q (nm-1) and the vertical axis was taken as the common logarithm of the intensity I (q) for plotting. Here, the calculation range of the distribution is set to ± 5 degrees from the width direction.

(7) DSC (Differential Scanning Calorimetry)

The thermal measurement was performed using a differential scanning calorimeter ("DSC-60" manufactured by Shimadzu Corporation). About 5 mg was cut out from the sample film and sealed in an aluminum pan for measurement. The temperature was raised from room temperature to 230 ° C at a rate of 20 ° C / minute, and the melting endothermic peak temperature and the melting endothermic peak area (total melting heat) of the sample were measured. Here, the baseline is set from the beginning of the endothermic wave to the end of the wave, and the curve is connected smoothly at the temperature before and after melting. In addition, among the areas of the melting endothermic peaks, the area of a portion of 150 ° C. or lower is regarded as the melting heat of 150 ° C.

(8) Thermal shrinkage (unit:%)

The measurement was performed in accordance with JISZ 1712: 2009 by the following method. The film substrate and the laminated film were cut into 5 places each in the longitudinal direction and the transverse direction with a width of 20 mm and a length of 200 mm, and were suspended in a hot air oven at 150 ° C. and heated for 15 minutes. The length of the marked line at about 50 mm intervals after heating was measured, and the ratio (percentage) of the contracted length to the original length was taken as the thermal shrinkage.

(9) Young's rate (unit: GPa)

The Young's ratios in the longitudinal and transverse directions of the film substrate and the laminated film were measured at 23 ° C in accordance with JIS K 7127: 1999. The film base material and the laminated film were respectively cut into 5 places in the longitudinal direction and the transverse direction with a width of 15 mm and a length of 200 mm, and the tensile strength when the tensile test was performed at a tensile speed of 200 mm / min. Was measured.

(10) Impact resistance (Unit: J)

The measurement was performed at 23 ° C using a "Film Impact Tester (impact head: 12.7 mm)" manufactured by Toyo Seiki. The film substrate was cut into 5 places each having a width (horizontal direction): 105 mm and a length (longitudinal direction): 297 mm, and the impact strength was measured.

(11) Uniform thickness (uneven thickness) (unit:%)

A sample of a square having a length of 1 m was cut out from the film roll, and was divided into ten equal parts in the longitudinal direction and the horizontal direction to prepare 100 samples for measurement. The thickness was measured with a contact-type film thickness meter at approximately the center of the measurement sample. Calculate the average value A of the 100 points obtained, and find the difference (absolute value) B between the minimum and maximum values. Use the value calculated by the formula (B / A) × 100 as the thickness of the film. Both.

(12) Haze (unit:%)

The film substrate was measured in accordance with JIS K7136: 1999.

(13) Film density (unit: g / cm ³ )

The density of the film substrate is measured by a density gradient tube method in accordance with JIS K7112: 1999.

(14) refractive index (Nx, Ny, Nz)

The film substrate was measured using an Abbe refractometer (manufactured by Atago) under conditions of 23 ° C. and 65% humidity with benzyl alcohol and a measurement wavelength of 589 nm (sodium D-ray). The refractive indices in the vertical and horizontal directions are respectively Nx and Ny, and the refractive index in the thickness direction is Nz.

(15) Plane orientation coefficient P

Using Nx, Ny, and Nz measured in the above (14), it is calculated from the formula: P = [(Nx + Ny) / 2] -Nz.

(Composition and film thickness of inorganic thin film layer)

Regarding the composition film thickness of the inorganic compound, a fluorescent X-ray analyzer (ZSX100e manufactured by Rigaku) was used to measure the film thickness composition using a calibration curve prepared in advance. The conditions for exciting the X-ray tube were 50 kV and 70 mA.

The calibration curve is obtained in the following order.

Several kinds of films having an inorganic compound thin film containing aluminum oxide and silicon oxide were produced, and the respective adhesion amounts of aluminum oxide and silicon oxide were determined by an ICP (Inductively Coupled Plasma) light emission method. Next, the fluorescent X-ray analyzer (ZSX100e manufactured by Rigaku, conditions for exciting X-ray tubes: 50kv, 70mA) was used to analyze each film for which the adhesion amount had been obtained, thereby obtaining the oxidation of each sample. X-ray fluorescence intensity of aluminum and silicon oxide. Then, the relationship between the fluorescence X-ray intensity and the amount of adhesion obtained by ICP was determined, and a calibration curve was prepared.

Since the adhesion amount obtained by ICP is basically mass, in order to adjust the mass to a film thickness composition, the conversion is performed as follows.

Regarding the film thickness, the density of the inorganic oxidized thin film was regarded as 80% of the bulk density, and the volume was calculated while maintaining the volume even when the alumina and silica were mixed.

If the adhesion amount of alumina per unit area is set to Ma (g / cm ² ), and the adhesion amount of silicon oxide per unit area is set to Ms (g / cm ² ), the content rate of alumina in the film The wa (mass%) and the content of silicon oxide in the film ws (mass%) are obtained from the following formulas (1) and (2), respectively.

wa = 100 × [Ma / (Ma + Ms)] ‧‧‧Formula (1)

ws = 100-wa‧‧‧Formula (2)

That is, if the adhesion amount of alumina per unit area is set to Ma (g / cm ² ), the bulk density of the alumina is set to ρ a (3.97 g / cm ³ ), and The adhesion amount of silicon oxide is set to Ms (g / cm ² ), and the bulk density of the silicon oxide is set to ρ s (2.65 g / cm ³ ). The film thickness t (nm) is given by the following formula (3) Find it out.

t = ((Ma / (ρ a × 0.8) + Ms / (ρ s × 0.8)) × 10 ⁷ ‧‧‧Eq. (3)

The film thickness measured by fluorescent X-rays is close to the film thickness actually measured using TEM (Transmission Electron Microscope).

(17) Oxygen transmission rate (mL / m ² / day / MPa)

Using an oxygen transmission measuring device (OX-TRAN2 / 21 manufactured by MOCON), the polypropylene film substrate, the laminated polypropylene film, and the above-mentioned laminated laminate were measured at a temperature of 23 ° C and a relative humidity of 65%. It is set so that the surface on the opposite side to the inorganic thin film layer becomes the humidity control side.

(18) Water vapor transmission rate (g / m ² .day)

As for the water vapor transmission rate, a water vapor transmission rate measuring device (PERMATRAN-W3 / 33 manufactured by MOCON Corporation) was used to perform a polypropylene film substrate, a laminated polypropylene film, and a film at a temperature of 37.8 ° C and a relative humidity of 90%. Measurement of the laminated laminate produced in the following procedure. It is set so that the surface opposite to the inorganic thin film layer becomes the high humidity side.

(16) Lamination strength

The lamination strength was measured by the following procedure.

<1> Fabrication of laminated laminate with sealing film

A continuous dry laminator was used to operate as follows.

The corona surface of the laminated polypropylene film obtained in Examples and Comparative Examples was gravure-coated with an adhesive so that the coating amount became 3.0 g / m ² when dried, and then introduced into a drying zone and dried at 80 ° C. for 5 seconds. bell. Then, the sealing film was bonded between the rollers provided on the downstream side (roller pressure: 0.2MP, roller temperature: 60 ° C). The obtained laminated laminate was subjected to an aging treatment at 40 ° C. for 3 days in a rolled state.

The adhesive used was a base agent (TM329 manufactured by Toyo Morton) 17.9% by mass, a hardener (CAT8B manufactured by Toyo Morton) 17.9% by mass, and ethyl acetate 64.2. The ether-based adhesive obtained by mixing by mass%, and the sealing film was a non-stretch polypropylene film (Pyren (registered trademark) CT P1128, thickness 30 μm) manufactured by Toyobo Co., Ltd.

<2> Measurement of lamination strength

The obtained laminated laminated body was cut out in the shape of a short strip (length 200 mm, width 15 mm) with long sides along the longitudinal direction of the biaxially oriented polypropylene film, and a tensile tester (Tensilon, Orientic Corporation) was used. (Manufactured), T-shaped peeling was performed at a stretching speed of 200 mm / min in an environment at 23 ° C, and the peel strength (N / 15 mm) at this time was measured. The measurement was performed three times, and the average of the three measurements was taken as the lamination strength.

(Example 1)

As the polypropylene-based resin, a propylene homopolymer (Japan) with Mw / Mn = 7.7, Mz + 1 / Mn = 140, MFR = 5.0 g / 10 minutes, and meso pentad component ratio [mmmm] = 97.3% (Japan "Novatec (registered trademark) PP SA4L" manufactured by Japan Polypropylene (stock): the amount of comonomer is 0 mole%; hereinafter referred to as "PP-1").

This polypropylene resin was extruded from a T-die as a sheet at a temperature of 250 ° C using a 60mm uniaxial extruder, and was cooled and solidified by a cooling roller at 30 ° C. Then, it was longitudinally (vertically) at 135 ° C. The longitudinal direction is extended to 4.5 times, then the two ends are clamped by a chuck and introduced into a hot air oven. After preheating at 170 ° C, the horizontal direction (width direction) is extended to 8.2 times at 160 ° C, and then one side Heat treatment was performed at 168 ° C while performing a relaxation of 6.7%. Then, corona treatment is performed on one side of the film, and it is taken up by a winder to prepare an extended polypropylene film used as a substrate of the present invention.

The thickness of the obtained film was 20 μm. Table 1 shows the characteristics of the polypropylene constituting the film, and Table 2 shows the film forming conditions. The physical properties of the obtained film are shown in Table 3. The thermal shrinkage was low and the Young's rate was high. A graph obtained by differential scanning calorimetry (DSC) of the film is shown in FIG. 2.

As a vapor deposition source, particulate Al ₂ O ₃ (purity: 99.5%) and SiO ₂ (purity: 99.9%) having a size of about 3 mm to 5 mm were simultaneously deposited on the stretched polypropylene film by an electron beam evaporation method. Al ₂ O ₃ and SiO ₂ form an Al ₂ O ₃ -SiO ₂ based thin film layer. Regarding the vapor deposition material, a circular crucible with a diameter of 40 mm was separated into two by a carbon plate, and granular Al ₂ O ₃ and granular SiO ₂ were separately charged without mixing. An electron gun was used as a heating source, and Al ₂ O ₃ and SiO ₂ were separately heated by irradiating the electron beams in a time-division manner, heated and vaporized on the surface of a polypropylene film, and Al ₂ O ₃ and SiO _{2 were} mixed and evaporated. At this time, the emission current of the electron gun was 205 mA, and the acceleration voltage was 6 kV. Electric power equivalent to 160 mA × 6 kV was input to the alumina injected into the crucible, and electric power equivalent to 45 mA × 6 kV was applied to the silicon oxide. The vacuum pressure at the time of vapor deposition was set to 1.1 × 10 ^-4 Pa, and the temperature of the roll supporting the film was set to 23 ° C. By changing the film-forming speed, a crystal oscillator-type film thickness meter was used to evaporate so that the thickness of the film layer became 20 nm, thereby obtaining a laminated polypropylene film. The obtained film physical properties are shown in Table 3.

(Example 2)

As the polypropylene resin, a propylene homopolymer (Samsung Total (shares)) of Mw / Mn = 8.9, Mz + 1 / Mn = 110, MFR = 3.0g / 10 minutes, and [mmmm] = 97.1% was used. Manufactured "HU300": The amount of comonomer is 0 mole%; hereinafter referred to as "PP-2"), the preheating temperature during lateral stretching is 171 ° C, and the lateral stretching temperature is 161 ° C Except that the heat treatment temperature after stretching in the transverse direction was set to 170 ° C., a stretched polypropylene film was obtained as a substrate of the present invention in the same manner as in Example 1.

The thickness of the obtained film was 20 μm. Table 1 shows the structure of the polypropylene constituting the film, and Table 2 shows the film forming conditions. The physical properties of the obtained film are shown in Table 3.

In the same manner as in Example 1, an inorganic thin film layer was deposited on the stretched polypropylene film. The obtained film physical properties are shown in Table 3.

(Example 3)

With respect to 90 parts by mass of the propylene homopolymer (PP-1) used in Example 1, a low molecular weight propylene having a molecular weight of 10,000 (Hi-wax "NP105" manufactured by Mitsui Chemicals Co., Ltd. was added: the amount of comonomer was 0 Mol%) 10 parts by mass and set to a total of 100 parts by mass, melt-kneaded with a 30 mm biaxial extruder to obtain Mw / Mn = 111, Mz + 1 / Mn = 146, MFR = 7.0g / 10 minutes, [ mmmm] = 96.5% of a mixture of propylene polymers (hereinafter referred to as "PP-3"). A stretched polypropylene film used in the substrate of the present invention was obtained in the same manner as in Example 1 except that the particles were used as a polypropylene-based resin.

The thickness of the obtained film was 20 μm. Table 1 shows the structure of the polypropylene constituting the film, and Table 2 shows the film forming conditions. The physical properties of the obtained film are shown in Table 3.

In the same manner as in Example 1, an inorganic thin film layer was deposited on the stretched polypropylene film. The obtained film physical properties are shown in Table 3.

(Example 4)

A stretched polypropylene film used for the substrate of the present invention was obtained in the same manner as in Example 3, except that the length was extended to 5.5 times in the longitudinal direction and 12 times in the transverse direction.

The thickness of the obtained film was 20 μm. Table 1 shows the characteristics of the polypropylene constituting the film, and Table 2 shows the film forming conditions. The physical properties of the obtained film are shown in Table 3.

In the same manner as in Example 1, an inorganic thin film layer was deposited on the stretched polypropylene film. The obtained film physical properties are shown in Table 3.

(Example 5)

For the stretched polypropylene film produced in Example 1, the two ends in the width direction of the film were clamped in a tenter in a tenter, and heat treatment was performed at 170 ° C. for 5 minutes to obtain the stretched polypropylene film of the present invention.

The thickness of the obtained film was 20 μm. Table 1 shows the characteristics of the polypropylene constituting the film, and Table 2 shows the film forming conditions. The physical properties of the obtained film are shown in Table 3.

In the same manner as in Example 1, an inorganic thin film layer was deposited on the stretched polypropylene film. The obtained film physical properties are shown in Table 3.

(Example 6)

As the polypropylene-based resin, a propylene homopolymer having a Mw / Mn = 4.0, Mz + 1 / Mn = 23, MFR = 6.0g / 10 minutes, and [mmmm] = 98.7% (the comonomer amount was 0 mol %; Hereinafter simply referred to as "PP-4"), except that a stretched polypropylene film used for the substrate of the present invention was obtained in the same manner as in Example 1.

The thickness of the obtained film was 20 μm. Table 1 shows the structure of the polypropylene constituting the film, and Table 2 shows the film forming conditions. The physical properties of the obtained film are shown in Table 3.

In the same manner as in Example 1, an inorganic thin film layer was deposited on the stretched polypropylene film. The obtained film physical properties are shown in Table 3.

(Example 7)

Laminated film with B layer (B layer / A layer / B layer) laminated on both sides of layer A. The polypropylene homopolymer PP-4 shown in Table 1 is used in layer A. The layer B is used in the table. The polypropylene homopolymer PP-8 shown in 1 is prepared by blending 0.15% by mass of silicon dioxide as an anti-blocking agent. By laminating the B layer, the lamination strength can be improved. Layer A uses a 60mm extruder and Layer B uses a 65mm extruder. It is extruded from a T-die in sheet form at 250 ° C, cooled and solidified by a cooling roll at 30 ° C, and stretched at 135 ° C along the longitudinal direction. The direction extends to 4.5 times. Then, the two ends in the width direction of the film were clamped by a chuck in the tenter, and after preheating at 170 ° C, it was extended to 8.2 times in the width direction at 160 ° C, and was heat-fixed at 168 ° C while being relaxed by 6.7%. A biaxially stretched laminated polypropylene film obtained by laminating each of the A layer and the B layer was obtained. Corona treatment is performed on the B layer side of the laminated polypropylene film, and it is wound by a coiler. The thickness of the obtained film was 20 μm. Table 1 shows the structure of the polypropylene-based resin raw material, and Table 2 shows the film forming conditions.

The physical properties of the obtained film are shown in Table 3.

In the same manner as in Example 1, an inorganic thin film layer was deposited on the stretched polypropylene film. The obtained film physical properties are shown in Table 3.

(Comparative example 1)

As the polypropylene-based resin, a propylene-ethylene copolymer (manufactured by Sumitomo Chemical Co., Ltd., Mw / Mn = 4, Mz + 1 / Mn = 21, MFR = 2.5g / 10 minutes, and [mmmm] = 97.0% was used. Sumitomo Nobrene (registered trademark) FS2011DG3 ": The amount of comonomer is 0.6 mole%; hereinafter referred to as" PP-5 "), the extension temperature in the longitudinal direction is set to 125 ° C, and the preheating temperature in the transverse direction is set. A stretched polypropylene film was obtained in the same manner as in Example 1 except that the stretching temperature in the transverse direction was set to 155 ° C, and the heat treatment temperature after the transverse stretching was set to 163 ° C.

The thickness of the obtained film was 20 μm. Table 1 shows the characteristics of the polypropylene constituting the film, and Table 2 shows the film forming conditions. The physical properties of the obtained film are shown in Table 4.

In the same manner as in Example 1, an inorganic thin film layer was deposited on the stretched polypropylene film. The obtained film physical properties are shown in Table 4.

(Comparative example 2)

Except that the preheating temperature during horizontal stretching was 171 ° C., the horizontal stretching temperature was 160 ° C., and the heat treatment temperature after horizontal stretching was 165 ° C., an extension polymerization was obtained in the same manner as in Comparative Example 1. Acrylic film.

The thickness of the obtained film was 20 μm. Table 1 shows the characteristics of the polypropylene constituting the film, and Table 2 shows the film forming conditions. The physical properties of the obtained film are shown in Table 4.

In the same manner as in Example 1, an inorganic thin film layer was deposited on the stretched polypropylene film. The obtained film physical properties are shown in Table 4.

(Comparative example 3)

As the polypropylene-based resin, a propylene homopolymer of Mw / Mn = 4.3, Mz + 1 / Mn = 28, MFR = 0.5g / 10 minutes, and [mmmm] = 97.0% (the amount of comonomers was 0 mol %; Hereinafter abbreviated as "PP-6"), except that a stretched polypropylene film was obtained in the same manner as in Comparative Example 2.

In the same manner as in Example 1, an inorganic thin film layer was deposited on the stretched polypropylene film. The obtained film physical properties are shown in Table 4.

The thickness of the obtained film was 20 μm. Table 1 shows the structure of the polypropylene constituting the film, and Table 2 shows the film forming conditions. The physical properties of the obtained film are shown in Table 4.

(Comparative Example 4)

As the polypropylene-based resin, a polypropylene-based polymer (Japan Polypropylene) (Mw / Mn = 2.8, Mz + 1 / Mn = 9.2, MFR = 30g / 10 minutes, and [mmmm] = 97.9%) was used. ) Manufactured by "Novatec (registered trademark) PP SA03": the amount of comonomer is 0 mole%; hereinafter referred to as "PP-7"), except that an attempt was made to obtain an extended polypropylene film in the same manner as in Example 1. However, the film is broken due to the lateral extension and cannot be biaxially extended. The reason for the fracture is that the alignment in the longitudinal direction is performed when the traveling direction is extended, and the fracture is broken when the extension is in the vertical direction.

(Comparative example 5)

In addition, the longitudinal stretching temperature was set to 125 ° C, the preheating temperature during the transverse stretching was set to 168 ° C, the transverse stretching temperature was set to 155 ° C, and the heat treatment temperature after the transverse stretching was set to 163 ° C. A stretched polypropylene film was obtained in the same manner as in Example 1.

The thickness of the obtained film was 20 μm. Table 1 shows the characteristics of the polypropylene constituting the film, and Table 2 shows the film forming conditions. The physical properties of the obtained film are shown in Table 4.

In the same manner as in Example 1, an inorganic thin film layer was deposited on the stretched polypropylene film. The obtained film physical properties are shown in Table 4.

    [Industrial availability]    

The laminated polypropylene film of the present invention can be widely used in packaging applications, industrial applications, and the like. In particular, the laminated polypropylene film can be thinned due to excellent gas barrier properties, and can reduce costs and weight. In addition, since the laminated polypropylene film of the present invention has high heat resistance, it can be subjected to high-temperature processing during coating or printing, which can realize production efficiency or use coating agents, inks, and laminating adhesives that have been difficult to use in the past. Wait. In addition, the polypropylene film of the present invention is also shown in a substrate film of an insulating film such as a capacitor or a motor, a back sheet of a solar cell, and a transparent conductive film such as ITO (Indium Tin Oxide).

Claims (4)

A laminated polypropylene film comprising a polypropylene film base material using a polypropylene resin and an inorganic thin film layer containing an inorganic compound as a main component; the laminated polypropylene film has a thermal shrinkage rate of 7% in the longitudinal direction at 150 ° C Hereinafter, the oxygen permeability is 150 mL / m ² / day / MPa or less.     The laminated polypropylene film according to claim 1, wherein the haze is 6% or less.         The laminated polypropylene film according to claim 1 or 2, wherein a heat shrinkage rate of the laminated polypropylene film in a transverse direction at 150 ° C is 7% or less.         A laminated body comprising the laminated polypropylene film and the polyolefin film according to any one of claims 1 to 3.