Laminate film and package

Abstract

To provide a laminate film having excellent moldability during hot forming and a package composed using the laminate film.SOLUTION: Provided is a laminate film 1 including a functional layer 11 and an oxygen barrier layer 12, in which an extensional viscosity of the laminate film 1 at an extensional speed of 50-70 s-1 calculated by the Cogswell method from measurement data of the laminate film 1 at a temperature of 240°C when a twin capillary rheometer is used is more than or equal to 9300 Pa s. Also provided is a package composed using the laminate film 1.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a laminate film and a packaging material. [Background technology]

[0002] Laminated films formed by laminating multiple resin layers are widely used as materials for packaging. A typical laminated film includes at least a sealant layer provided for heat sealing to an object to be sealed, and an outer layer provided on the opposite side to the sealant layer.

[0003] On the other hand, because of their high convenience, such laminated films for packaging applications are produced and consumed in large quantities all over the world every day, and a large amount of waste is generated after use. From the viewpoint of improving the global environment, the generation of waste is an important issue that needs to be resolved, and in recent years, methods for reducing the amount of waste generated as well as for reusing (recycling) waste have been actively studied.

[0004] For example, if the main constituent materials of the multiple resin layers in a laminate film are of the same type, there is no need to separate and reuse each resin layer separately, and the entire laminate film can be easily reused, making it more useful. As such a laminate film, for example, a polyethylene laminate for packaging materials has been disclosed which comprises at least a stretched polyethylene film, an adhesive layer, and a heat-sealable polyethylene layer, the adhesive layer containing a solventless adhesive (see Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-189333 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, when the main constituent material of the multiple resin layers in a laminate film is, for example, polypropylene, when the laminate film is heated during molding, the heated parts of the laminate film sag (draw down) due to the fluidity of polypropylene, making molding difficult.

[0007] An object of the present invention is to provide a laminate film that has excellent formability during heat forming, and a packaging body that is constructed using the laminate film. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention employs the following configuration. [1] A laminated film having a functional layer and an oxygen barrier layer, the laminated film having an elongation rate of 50 to 70 s calculated by the Cogswell method from the measurement data at a temperature of 240 ° C. when using a twin capillary rheometer. -1 The laminate film has an elongational viscosity of 9,300 Pa·s or more at [2] The functional layer contains a propylene-based polymer (P1), and the elongation rate is 60 to 100 s 2 calculated by the Cogswell method from measurement data at a temperature of 240° C. when a twin capillary rheometer is used. -1 The laminate film according to [1], wherein the functional layer has an elongational viscosity of 10,000 Pa·s or more at . [3] The laminate film according to [2], wherein the functional layer further comprises one or both of an ethylene-based polymer (e1) and a polypropylene (z1) as the propylene-based polymer (P1), and when the functional layer comprises the polypropylene (z1), the functional layer also comprises the propylene-based polymer (P1) other than the polypropylene (z1). [4] The laminate film according to [3], wherein the propylene-based polymer (P1) and the ethylene-based polymer (e1) have melt flow rates of 3 g / 10 min or less. [5] The elongation rate of 60 to 100 s calculated by the Cogswell method from the measurement data of the polypropylene (z1) at a temperature of 240 ° C. when a twin capillary rheometer is used. -1 The laminate film according to [3] or [4], wherein the polypropylene (z1) has an elongational viscosity of 10,000 Pa s or more at .

[0009] [6] An elongation rate of 60 to 100 s calculated by the Cogswell method from measurement data of the ethylene polymer (e1) at a temperature of 240° C. when a twin capillary rheometer is used. -1 The laminate film according to any one of [3] to [5], wherein the ethylene polymer (e1) has an extensional viscosity of 10,000 Pa·s or more at . [7] The laminate film described in any one of [3] to [6], wherein in the functional layer, the ratio of the combined content of the polypropylene (z1) and the ethylene polymer (e1) to the total mass of the functional layer is 3 mass% or more. [8] The laminate film according to [2] or [3], wherein the propylene-based polymer (P1) is either or both of a propylene-ethylene block copolymer and a homopolypropylene. [9] The laminate film according to any one of [1] to [8], further comprising an inner layer as one of the outermost layers, the inner layer containing a propylene-based polymer (P2), and further containing either or both of an ethylene-based polymer (e2) and a polypropylene (z2) as the propylene-based polymer (P2), and when the inner layer contains the polypropylene (z2), the inner layer also contains the propylene-based polymer (P2) other than the polypropylene (z2).

[10] The elongation rate of 60 to 100 s calculated by the Cogswell method from the measurement data of the polypropylene (z2) at a temperature of 240 ° C. when a twin capillary rheometer is used. -1 The laminate film according to [9], wherein the polypropylene (z2) has an elongational viscosity of 10,000 Pa·s or more at .

[0010]

[11] An elongation rate of 60 to 100 s calculated by the Cogswell method from measurement data of the ethylene polymer (e2) at a temperature of 240° C. when a twin capillary rheometer is used. -1 The laminate film according to [9] or

[10] , wherein the ethylene polymer (e2) has an elongational viscosity of 10,000 Pa·s or more at .

[12] The laminate film according to any one of [1] to

[11] , further comprising an outer layer as the other outermost layer, the outer layer containing a propylene-based polymer (P3) and further containing either or both of an ethylene-based polymer (e3) and a polypropylene (z3) as the propylene-based polymer (P3), and when the outer layer contains the polypropylene (z3), the outer layer also contains the propylene-based polymer (P3) other than the polypropylene (z3).

[13] The elongation rate of 60 to 100 s calculated by the Cogswell method from the measurement data of the polypropylene (z3) at a temperature of 240 ° C. when a twin capillary rheometer is used. -1 The laminate film according to

[12] , wherein the polypropylene (z3) has an elongational viscosity of 10,000 Pa s or more at .

[14] An elongation rate of 60 to 100 s calculated by the Cogswell method from measurement data of the ethylene polymer (e3) at a temperature of 240°C when a twin capillary rheometer is used. -1 The laminate film according to

[12] or

[13] , wherein the ethylene polymer (e3) has an elongational viscosity of 10,000 Pa·s or more at

[15] The laminate film according to any one of [1] to [8], further comprising an inner layer as one outermost layer and an outer layer as the other outermost layer, the inner layer containing a propylene-based polymer (P2) and further containing either one or both of an ethylene-based polymer (e2) and a polypropylene (z2) as the propylene-based polymer (P2), and when the inner layer contains the polypropylene (z2), the propylene-based polymer (P2) other than the polypropylene (z2) is also contained; the outer layer containing a propylene-based polymer (P3) and further containing either one or both of an ethylene-based polymer (e3) and a polypropylene (z3) as the propylene-based polymer (P3), and when the outer layer contains the polypropylene (z3), the propylene-based polymer (P3) other than the polypropylene (z3) is also contained; and a ratio of a total thickness of the functional layer, the inner layer and the outer layer to a thickness of the laminate film is 85% or more.

[0011]

[16] The laminate film according to any one of [1] to

[15] , wherein the proportion of the polyolefin resin in the total mass of the laminate film is 80 mass% or more.

[17] The laminate film according to any one of [1] to

[16] , wherein the oxygen barrier layer contains an ethylene-vinyl alcohol copolymer.

[18] The laminate film described in any one of [1] to

[17] , wherein the laminate film has a pair of the functional layers, and the oxygen barrier layer is provided between the pair of the functional layers.

[19] The tensile impact strength of the laminated film in a direction perpendicular to the resin flow direction is 190 kJ / m 2 The laminate film according to any one of [1] to

[18] above.

[20] The laminate film according to any one of [1] to

[19] , wherein when the laminate film is heated at 400° C. for 120 seconds, the drawdown length of the laminate film is 50 mm or less.

[21] A laminated film having a functional layer and an oxygen barrier layer, wherein the elongation rate is 60 to 100 s 2 calculated by the Cogswell method from the measurement data of the laminated film at a temperature of 240 ° C. when using a twin capillary rheometer. -1 The laminate film has an elongational viscosity of 9800 Pa·s or more at

[22] A packaging body formed using the laminate film according to any one of [1] to

[21] . Effect of the Invention

[0012] According to the present invention, there are provided a laminate film having excellent formability during thermoforming, and a package formed using said laminate film. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a diagram showing a schematic diagram of an example of a method for measuring the drawdown length of a laminated film or a monolayer film. [Diagram 2] FIG. 1 is a cross-sectional view illustrating an example of a laminated film according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a cross-sectional view illustrating a schematic view of another example of a laminate film according to one embodiment of the present invention. [Figure 4] FIG. 1 is a cross-sectional view showing a schematic example of a packaging body according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] <<Laminated film>> The laminated film according to one embodiment of the present invention has a functional layer and an oxygen barrier layer, and has an elongation rate of 50 to 70 s 2 calculated by the Cogswell method from measurement data of the laminated film at a temperature of 240° C. when a twin capillary rheometer is used. -1 The elongational viscosity of the laminated film at is 9,300 Pa·s or more. Since the laminate film of the present embodiment exhibits such an elongational viscosity, when the laminate film is heat-molded to produce a package using the laminate film, the heated portion of the laminate film sags, which is called drawdown, and therefore the molded product obtained by heat-molding the laminate film has the shape and size as designed, and the laminate film has excellent moldability during heat molding. Furthermore, as described below, the laminated film of this embodiment can have polyolefin as the main constituent material of its multiple resin layers. In particular, by using polypropylene, which has high fluidity at high temperatures, the laminated film can have excellent formability during hot molding and excellent recyclability.

[0015] [Extensional viscosity of laminated film] The extensional viscosity of the laminated film of this embodiment can be measured by a known method. In this embodiment, a measurement sample is prepared from the laminated film, and data of the measurement sample (laminated film) is measured using a twin capillary rheometer. More specifically, a capillary die (also known as a long die) and an orifice die (also known as a short die) are used to measure the pressure difference (pressure loss) of the measurement sample (melt) between the inlet and outlet of each die, and the measurement value at the capillary die is corrected with the measurement value at the orifice die, and the corrected shear stress and shear rate are calculated from the corrected value by the Bagley correction. Furthermore, from these calculated values, the Cogswell method is used to calculate the shear stress and shear rate when the measurement temperature (temperature of the measurement sample) is 240°C and the elongation rate of the measurement sample is 50 to 70 s -1 Calculate the extensional viscosity (Pa s) of the measurement sample when the viscosity is 1. This calculated value is used as the extensional viscosity of the measurement sample (laminated film).

[0016] An example of a sample for measuring the extensional viscosity of a laminated film is a test piece prepared by cutting the laminated film into a square or nearly square shape measuring about 5 mm×about 5 mm.

[0017] In this specification, the term "extensional viscosity" refers to the value determined by the above-mentioned method, unless otherwise specified, not only in the case of the measurement sample of the laminate film described above. In this specification, not limited to the case of the above-mentioned laminate film measurement sample, measuring the pressure loss of a sample and calculating the extensional viscosity by the above-mentioned method may be simply referred to as "measuring the extensional viscosity."

[0018] The elongation viscosity of the laminated film of this embodiment is 9300 Pa·s or more, and the elongation rate is 50 to 70 s, calculated by the Cogswell method from the measurement data at a temperature of 240°C. -1 The minimum elongational viscosity of the laminated film at 50 to 70 s is 9300 Pa s or more. -1 In the entire elongation speed range, the elongation viscosity of the laminated film is 9,300 Pa·s or more. The extensional viscosity (minimum value of extensional viscosity) of the laminate film of this embodiment is preferably 9800 Pa s or more, and more preferably 10300 Pa s or more. The higher the extensional viscosity of the laminate film, the higher the effect of suppressing drawdown during heat molding of the laminate film, and the higher the moldability of the laminate film during heat molding tends to be.

[0019] The upper limit of the elongational viscosity of the laminated film is not particularly limited. In order to more easily realize the desired laminated film, the elongational viscosity (maximum value of elongational viscosity) of the laminated film is preferably 20,000 Pa·s or less. That is, the elongational viscosity (maximum value of elongational viscosity) of the laminated film is preferably 20,000 Pa·s or less at an elongation rate of 50 to 70 s calculated by the Cogswell method from the measurement data of the laminated film at a temperature of 240°C. -1 The maximum elongational viscosity of the laminated film at 50 to 70 s is preferably 20,000 Pa·s or less. -1 In the entire elongation speed range, the elongation viscosity of the laminated film is preferably 20,000 Pa·s or less.

[0020] The extensional viscosity of the laminated film can be adjusted by, for example, adjusting the type and content of the components contained in any of the layers constituting the laminated film, such as the functional layer and the oxygen barrier layer. In particular, the extensional viscosity of the laminated film can be more easily adjusted by adjusting the type and content of the components contained in the functional layer. In particular, the extensional viscosity of the laminated film can be more easily adjusted by adjusting the type and content of the components contained in the functional layer and adjusting the extensional viscosity of the functional layer described later.

[0021] [Laminated film drawdown length] When the laminate film of this embodiment is heated for 120 seconds at 400° C., the drawdown length of the laminate film is preferably 50 mm or less, more preferably 45 mm or less, and may be, for example, any one of 40 mm or less, 37 mm or less, and 34 mm or less. When the drawdown length is equal to or less than the upper limit, the drawdown of the laminate film is further suppressed when the laminate film is heated and formed, and further, the occurrence of wrinkles at the flange portion is further suppressed when the laminate film is heated and formed. On the other hand, the lower limit of the drawdown length is not particularly limited. For example, the drawdown length is preferably 3 mm or more, in order to make the laminated film more uniformly melted during heating and to improve the formability of the laminated film.

[0022] The drawdown length of the laminated film can be measured, for example, by the method described below. That is, a test piece is cut out from the laminated film, and the upper surface side of the test piece is indirectly heated at 400°C for 120 seconds using a heater. As the heater, a known heater can be used, for example, a movable rod heater can be used. The shape and size of the test piece are not particularly limited as long as the drawdown length can be accurately measured, but the shape is preferably rectangular, and in this case, the length is preferably 290 to 310 mm, and the width is preferably 150 to 170 mm. The length of the rectangular test piece may be 300 mm, and the width may be 160 mm. After heating the test piece at 400°C for 120 seconds, the heater is removed. Then, the lowest point of the test piece in the sagging (drawdown) direction is identified using a laser displacement meter, and the drawdown length of the test piece at this lowest point is measured.

[0023] The method for measuring the drawdown length of a laminated film will be described more specifically with reference to FIG. In addition, the figures used in the following explanation may show enlarged key parts for the sake of convenience in order to make the features of the present invention easier to understand, and the dimensional ratios of each component may not necessarily be the same as the actual ones.

[0024] More specifically, as shown in FIG. 1, a point on the surface 7a of the test piece 7 in the area where drawdown is not observed in the test piece 7 is defined as starting point P1, and a point on the surface 7a in the area where drawdown is observed in the test piece 7 in the area where drawdown is observed in the test piece 7 that is the furthest from starting point P1 in the drawdown direction is defined as end point P2, and the distance D in the drawdown direction from starting point P1 to end point P2 is defined as the drawdown length of the laminated film.

[0025] Here, the method for measuring the drawdown length of a laminated film (test piece) has been explained, but the drawdown length of a single-layer film that does not have a laminated structure of two or more layers can also be measured by the same method as above.

[0026] The drawdown length of the laminate film can be adjusted, for example, by adjusting the elongational viscosity of the laminate film. In addition, the drawdown length of the laminate film can be adjusted, for example, by adjusting the type and content of the components contained in any of the layers constituting the laminate film, such as the functional layer and the oxygen barrier layer, as well as the thickness thereof. In particular, the drawdown length of the laminated film can be easily adjusted by adjusting the type and content of the components contained in the functional layer and the thickness of the functional layer. In particular, by increasing the content of polypropylene or ethylene polymer having an elongational viscosity of a specific value or more in any of the layers constituting the laminate film, such as the functional layer or the oxygen barrier layer, as described below, the drawdown length of the laminate film can be easily reduced. However, the method for adjusting the drawdown length of the laminated film is not limited to these.

[0027] [Tensile impact strength of laminated film] The laminated film of this embodiment has a tensile impact strength in the resin flow direction (machine direction, sometimes referred to as "MD" in this specification) of 200 kJ / m 2 It is preferable that the concentration is 250 kJ / m or more. 2 More preferably, it is 340 kJ / m or more. 2 More than 430kJ / m 2 or more, and 520 kJ / m 2 When the MD tensile impact strength of the laminate film is equal to or greater than the lower limit, the impact resistance of the laminate film is increased. On the other hand, the upper limit of the MD tensile impact strength of the laminate film is not particularly limited. For example, in order to more easily realize the desired laminate film, the MD tensile impact strength of the laminate film is preferably 800 kJ / m 2 It is preferable that:

[0028] The laminated film of this embodiment has a tensile impact strength in a direction perpendicular to the resin flow direction (MD) (transverse direction, sometimes referred to as "TD" in this specification) of 190 kJ / m 2 It is preferable that the concentration is 225 kJ / m or more. 2 More preferably, it is 300 kJ / m or more. 2 More than 380kJ / m 2 or more, and 450 kJ / m 2 When the TD tensile impact strength of the laminate film is equal to or greater than the lower limit, the impact resistance of the laminate film is increased. On the other hand, the upper limit of the TD tensile impact strength of the laminate film is not particularly limited. For example, in order to more easily realize the desired laminate film, the TD tensile impact strength of the laminate film is preferably 800 kJ / m 2 It is preferable that:

[0029] In this specification, the tensile impact strength of a resin film, not limited to the laminate film of this embodiment, in both MD and TD means a value measured in accordance with JIS K 7160A unless otherwise specified.

[0030] The tensile impact strength of the laminate film can be adjusted, for example, by adjusting the type and content of components contained in any of the layers constituting the laminate film, such as the functional layer and the oxygen barrier layer, as well as the thickness thereof. However, the method for adjusting the tensile impact strength of the laminated film is not limited to these.

[0031] The present invention will now be described in detail with reference to the drawings. FIG. 2 is a cross-sectional view that illustrates an example of the laminated film of the present embodiment. 2 includes a functional layer 11 and an oxygen barrier layer 12. More specifically, the laminated film 1 includes a first functional layer 111 and a second functional layer 112 at two locations in the thickness direction, and includes the oxygen barrier layer 12 between this pair of functional layers 11 (the first functional layer 111 and the second functional layer 112).

[0032] The laminated film 1 further includes an adhesive layer 15 between the pair of functional layers 11 and the oxygen barrier layer 12. More specifically, the laminated film 1 includes a first adhesive layer 151 between the first functional layer 111 and the oxygen barrier layer 12, and a second adhesive layer 152 between the second functional layer 112 and the oxygen barrier layer 12.

[0033] That is, the laminated film 1 is constructed by laminating a first functional layer 111, a first adhesive layer 151, an oxygen barrier layer 12, a second adhesive layer 152, and a second functional layer 112 in this order in the thickness direction. The adhesive layer 15 (the first adhesive layer 151 and the second adhesive layer 152) is of any configuration, and the laminated film 1 does not necessarily have to include these layers.

[0034] One side 111b of the first functional layer 111 (the side opposite the first adhesive layer 151, sometimes referred to as the "second side" in this specification) is the exposed surface (one of the outermost surfaces) and is the same as one side 1b of the laminated film 1. One side 112a of the second functional layer 112 (the side opposite the second adhesive layer 152, sometimes referred to as the "first side" in this specification) is the exposed surface (the other outermost surface) and is the same as the other side 1a of the laminated film 1. In the laminate film 1, the first functional layer 111 functions as a sealant layer during the production of the package.

[0035] The temperature was 240℃ and the extension speed was 50-70s. -1 The elongational viscosity of the laminated film 1 at this temperature is 9,300 Pa·s or more.

[0036] FIG. 3 is a cross-sectional view that illustrates a schematic diagram of another example of the laminated film of the present embodiment. In FIG. 3 and subsequent figures, the same components as those shown in the figures already described are given the same reference numerals as in the figures already described, and detailed description thereof will be omitted.

[0037] The laminated film 2 shown in FIG. 3 includes a first functional layer 111, a first adhesive layer 151, an oxygen barrier layer 12, a second adhesive layer 152, and a second functional layer 112, similar to the laminated film 1 shown in FIG. The laminated film 2 further includes an inner layer 13 as one outermost layer on the first functional layer 111 side, and an outer layer 14 as the other outermost layer on the second functional layer 112 side.

[0038] That is, the laminated film 2 is constructed by stacking an inner layer 13, a first functional layer 111, a first adhesive layer 151, an oxygen barrier layer 12, a second adhesive layer 152, a second functional layer 112, and an outer layer 14 in this order in the thickness direction. The inner layer 13, the outer layer 14 and the adhesive layer 15 (the first adhesive layer 151 and the second adhesive layer 152) are of any configuration, and the laminated film 2 may not include these layers. The laminated film 2 is the same as the laminated film 1, except that it further comprises an inner layer 13 as one outermost layer and an outer layer 14 as the other outermost layer.

[0039] One side 13b of the inner layer 13 (the side opposite the first functional layer 111, sometimes referred to as the "second side" in this specification) is the exposed surface (one of the outermost surfaces) and is the same as one side 2b of the laminated film 2. One side 14a of the outer layer 14 (the side opposite the second functional layer 112, sometimes referred to as the "first side" in this specification) is the exposed surface (the other outermost surface) and is the same as the other side 2a of the laminated film 2. In the laminate film 2, the inner layer 13 functions as a sealant layer during the production of the package.

[0040] The temperature was 240℃ and the extension speed was 50-70s.-1 The elongational viscosity of the laminated film 2 at this temperature is 9,300 Pa·s or more.

[0041] Each layer of the laminated film of the present embodiment will be described in more detail below. In the following, the ratio of the thickness of each layer to the thickness of the laminate film is described for each layer, but the total ratio of the thicknesses of each layer in the laminate film does not exceed 100%.

[0042] <Functional layer> The functional layer (for example, functional layer 11 shown in Figures 2 and 3) has the function of improving the effect of suppressing drawdown during heat molding of a laminate film (for example, laminate film 1 shown in Figure 2 and laminate film 2 shown in Figure 3) and improving the formability of the laminate film during heat molding. In the case where the laminated film does not have an inner layer described later, the functional layer also functions as a sealant layer when the laminated film is used to produce a package described later.

[0043] In the functional layer, the ratio of the total content of one or more components contained in the functional layer, which will be described later, to the total mass of the functional layer does not exceed 100 mass %. Similarly, in the composition for forming a functional layer described below, the ratio of the total content of one or more of the components contained in the composition for forming a functional layer described below to the total mass of the composition for forming a functional layer does not exceed 100 mass%.

[0044] The functional layer is preferably a resin layer containing a resin, and more preferably contains a polyolefin-based resin. The polyolefin resin contained in the functional layer may be a homopolymer of one type of olefin (alkene), or an olefin copolymer having structural units derived from two or more types of monomers (at least one of which is an olefin). The functional layer containing a polyolefin resin further improves the effect of suppressing drawdown during heat molding of the laminate film, and by making polyolefin the main constituent material (main component) of the multiple resin layers of the laminate film, it is advantageous in improving the recyclability of the laminate film.

[0045] In the present embodiment, not limited to the case of the functional layer, the polyolefin resin means a resin component having a structural unit derived from an olefin.

[0046] Examples of the polyolefin-based resin contained in the functional layer include an ethylene-based polymer (in this specification, the ethylene-based polymer contained in the functional layer may be particularly referred to as an "ethylene-based polymer (e1)") and a propylene-based polymer (in this specification, the propylene-based polymer contained in the functional layer may be particularly referred to as a "propylene-based polymer (P1)").

[0047] The ethylene-based polymer (ethylene-based polymer (e1)) contained in the functional layer is a polymer (resin component) having structural units derived from ethylene, and may be polyethylene (PE, for example, a homopolymer of ethylene) or an ethylene-based copolymer having structural units derived from ethylene and structural units derived from a monomer other than ethylene. However, among polyolefin-based resins (olefin-based copolymers) having structural units derived from ethylene and structural units derived from propylene, copolymers in which the number of structural units derived from propylene is greater than the number of structural units derived from ethylene are classified as propylene-based copolymers.

[0048] Among the ethylene polymers (e1) contained in the functional layer, examples of the polyethylene (PE) include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), metallocene-catalyzed linear low density polyethylene (mLLDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), etc., and low density polyethylene, linear low density polyethylene, or metallocene-catalyzed linear low density polyethylene is preferred.

[0049] In this specification, the density of low density polyethylene (LDPE), linear low density polyethylene (LLDPE) and metallocene-catalyzed linear low density polyethylene (mLLDPE) is 0.910 g / cm 3 More than 0.945g / cm 3 is less than. The density of medium density polyethylene (MDPE) is 0.945 g / cm 3 More than 0.955g / cm 3 is less than. The density of high density polyethylene (HDPE) is 0.955 g / cm 3 That's all.

[0050] The ethylene-based copolymer contained in the functional layer is preferably a resin other than an ethylene-vinyl alcohol copolymer (EVOH). Examples of ethylene-based copolymers contained in the functional layer include ethylene-vinyl acetate copolymer (EVA), ethylene-vinyl alcohol-vinyl acetate copolymer (also known as partially saponified ethylene-vinyl acetate copolymer, sometimes referred to in this specification as "partially saponified EVA"), ethylene-methyl acrylate copolymer (EMA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), and ionomers (ION). The ionomer may be, for example, a resin in which a copolymer of ethylene and a small amount of acrylic acid or methacrylic acid has an ionic crosslinking structure due to salt formation between the acid portion in the copolymer and a metal ion.

[0051] The propylene-based polymer (propylene-based polymer (P1)) contained in the functional layer is a polymer (resin component) having structural units derived from propylene, and may be a homopolymer of propylene (homopolypropylene, hPP) or a propylene-based copolymer having structural units derived from propylene and structural units derived from a monomer other than propylene.

[0052] Examples of the propylene-based copolymer contained in the functional layer include propylene-ethylene random copolymer (also known as polypropylene random copolymer (rPP)) and propylene-ethylene block copolymer (also known as polypropylene block copolymer (bPP)).

[0053] In this specification, the term "polypropylene" refers to a concept that includes homopolypropylene (hPP), propylene-ethylene random copolymer (rPP), and propylene-ethylene block copolymer (bPP). The polypropylene contained in the functional layer may be specifically referred to as "polypropylene (z1)."

[0054] The melt flow rate of the propylene polymer (P1) (sometimes referred to as "MFR" in this specification, not limited to the propylene polymer (P1)) is preferably 3 g / 10 min or less, and may be, for example, 2 g / 10 min or less or 1 g / 10 min or less. When the propylene polymer (P1) has a melt flow rate of not more than the upper limit, the effect of suppressing drawdown during heat molding of the laminate film is enhanced, and the formability of the laminate film during heat molding is enhanced.

[0055] In this specification, not only in the case of the propylene-based polymer (P1), but unless otherwise specified, the melt flow rate (also referred to as melt mass flow rate) means one measured in accordance with JIS K 7210-1:2014.

[0056] The lower limit of the melt flow rate of the propylene polymer (P1) is not particularly limited. For example, in order to improve the film-forming property of the functional layer, the melt flow rate of the propylene polymer (P1) is preferably 0.1 g / 10 min or more.

[0057] The melt flow rate of the propylene polymer (P1) can be adjusted, for example, by adjusting the melt tension or the weight average molecular weight of the propylene polymer (P1).

[0058] The density of the propylene polymer (P1) is 0.85 to 0.95 g / cm 3 and preferably 0.87 to 0.92 g / cm 3 More preferably, it is 0.89 to 0.91 g / cm 3 It is even more preferable that:

[0059] The melt flow rate (MFR) of the ethylene polymer (e1) is preferably 3 g / 10 min or less, and may be, for example, 2.5 g / 10 min or less. When the ethylene polymer (e1) has a melt flow rate of the above upper limit or less, the effect of suppressing drawdown during heat molding of the laminated film is enhanced, and the moldability of the laminated film during heat molding is enhanced.

[0060] The lower limit of the melt flow rate of the ethylene polymer (e1) is not particularly limited. For example, in terms of improving the film-forming property of the functional layer, the melt flow rate of the ethylene polymer (e1) is preferably 0.1 g / 10 min or more.

[0061] The density of the ethylene polymer (e1) is 0.89 to 0.97 g / cm 3 and preferably 0.90 to 0.95 g / cm3 More preferably, it is 0.91 to 0.93 g / cm 3 It is even more preferable that:

[0062] The functional layer may contain only one type of resin, or two or more types. When two or more types are contained, the combination and ratio thereof can be arbitrarily selected depending on the purpose. For example, the functional layer may contain one or more types of ethylene-based polymers (e1) and not contain a propylene-based polymer (P1), may contain one or more types of propylene-based polymers (P1) and not contain an ethylene-based polymer (e1), or may contain both one or more types of ethylene-based polymers (e1) and one or more types of propylene-based polymers (P1).

[0063] In terms of making it easier to adjust the elongational viscosity of the laminated film to a desired value, the functional layer preferably contains a propylene-based polymer (P1), more preferably contains a propylene-based polymer (P1) and an ethylene-based polymer (e1), or contains two or more types of propylene-based polymers (P1). It is particularly preferable that the functional layer contains one or two or more types of propylene-based polymers (P1) and an ethylene-based polymer (e1), and when two or more types of propylene-based polymers (P1) are contained, at least one of them is polypropylene (z1), or contains polypropylene (z1) and a propylene-based polymer (P1) other than polypropylene (z1). That is, the functional layer contains a propylene-based polymer (P1) and further contains either or both of an ethylene-based polymer (e1) and a polypropylene (z1) as the propylene-based polymer (P1). When the functional layer contains the polypropylene (z1), it is particularly preferable that the functional layer also contains a propylene-based polymer (P1) other than the polypropylene (z1).

[0064] In terms of making it easier to adjust the elongational viscosity of the laminated film to a desired value, the propylene-based polymer (P1) (e.g., polypropylene (z1) and a propylene-based polymer (P1) other than polypropylene (z1)) is preferably either one or both of a propylene-ethylene block copolymer (bPP) and a homopolypropylene (hPP).

[0065] In terms of particularly improving the effect of suppressing drawdown during heat molding of the laminate film and particularly improving the formability of the laminate film during heat molding, when the functional layer contains a propylene-based polymer (P1) and an ethylene-based polymer (e1), the melt flow rates of the propylene-based polymer (P1) and the ethylene-based polymer (e1) are preferably both in any of the above-mentioned numerical ranges. For example, the melt flow rates of the propylene-based polymer (P1) and the ethylene-based polymer (e1) are preferably 3 g / 10 min or less.

[0066] The elongation rate of 60 to 100 s calculated by the Cogswell method from the measurement data of the functional layer at a temperature of 240°C when using a twin capillary rheometer. -1 The extensional viscosity (minimum value of extensional viscosity) of the functional layer at 10000 Pa·s or more is preferably 60 to 100 s. -1 In the entire elongation speed range, the elongation viscosity of the functional layer is preferably 10,000 Pa s or more. A laminate film having such a functional layer can more easily adjust the elongation viscosity to a desired value. That is, a laminate film having such a functional layer can more easily suppress drawdown during heat molding, and can more easily improve formability during heat molding.

[0067] In terms of further enhancing the above-mentioned effects, the extensional viscosity (minimum value of the extensional viscosity) of the functional layer is more preferably 10100 Pa·s or more, and may be, for example, 10200 Pa·s or more.

[0068] The upper limit of the extensional viscosity of the functional layer is not particularly limited. In order to more easily realize the intended laminated film, the extensional viscosity (maximum value of extensional viscosity) of the functional layer is preferably 20,000 Pa·s or less. That is, when a twin capillary rheometer is used, the extensional viscosity (maximum value of extensional viscosity) of the functional layer is calculated by the Cogswell method from the measurement data at a temperature of 240°C of the functional layer at an extensional speed of 60 to 100 s -1 The maximum elongational viscosity of the functional layer at 60 to 100 s is preferably 20,000 Pa s or less. -1 In the entire elongation speed range, the elongation viscosity of the functional layer is preferably 20,000 Pa·s or less.

[0069] The elongation rate of 50 to 70 s calculated by the Cogswell method from the measurement data of the functional layer at a temperature of 240°C when using a twin capillary rheometer. -1 The elongation viscosity (minimum value of elongation viscosity) of the functional layer at elongation speed is preferably 10,000 Pa·s or more. -1 This provides the same effect as when the extensional viscosity (minimum value of extensional viscosity) of the functional layer is 10,000 Pa·s or more.

[0070] The above effects are further enhanced when the extension speed is 50-70s -1 The extensional viscosity (minimum value of extensional viscosity) of the functional layer in is more preferably 10100 Pa·s or more, and may be, for example, 11000 Pa·s or more.

[0071] Extension speed 50~70s -1 The upper limit of the elongational viscosity of the functional layer at an elongation speed of 50 to 70 s is not particularly limited. -1 The elongation viscosity (maximum value of elongation viscosity) of the functional layer at 20000 Pa·s or less is preferably 50 to 70 s. -1 In the entire elongation speed range, the elongation viscosity of the functional layer is preferably 20,000 Pa·s or less.

[0072] The elongational viscosity of the functional layer does not depend on the elongation rate, and for example, for test purposes, a functional layer identical to the functional layer in the laminated film (test functional layer) may be separately prepared, and this test functional layer may be measured in the same manner as the elongational viscosity of the laminated film described above. The extensional viscosity of the functional layer can be easily and accurately measured, for example, by preparing a test resin composition having the same composition (same types and amounts of the components) as the functional layer in the laminated film, and using granular matter (particles of the test resin composition) of the test resin composition having a particle size of about 1 to 10 mm. Except for this point, the extensional viscosity of the test resin composition may be measured, for example, by the same method as that for the extensional viscosity of the laminated film described above.

[0073] The functional layer preferably contains a polyolefin resin and has an extensional viscosity in any of the above-mentioned numerical ranges; more preferably contains a propylene-based polymer (P1) and has an extensional viscosity in any of the above-mentioned numerical ranges; further preferably contains a propylene-based polymer (P1) and an ethylene-based polymer (e1), or contains two or more propylene-based polymers (P1) and has an extensional viscosity in any of the above-mentioned numerical ranges; and particularly preferably contains one or more propylene-based polymers (P1) and an ethylene-based polymer (e1), and when it contains two or more propylene-based polymers (P1), at least one of them is polypropylene (z1), or contains polypropylene (z1) and a propylene-based polymer (P1) other than polypropylene (z1), and has an extensional viscosity in any of the above-mentioned numerical ranges. For example, the functional layer contains a propylene-based polymer (P1), and the elongation rate is calculated by the Cogswell method from the measurement data at a temperature of 240° C. of the functional layer when a twin capillary rheometer is used. -1 The elongation viscosity of the functional layer at the elongation speed may be 10,000 Pa·s or more, and the elongation speed may be 50 to 70 s -1 The elongational viscosity of the functional layer at may be 10,000 Pa·s or more. For example, the functional layer contains a propylene-based polymer (P1) and further contains one or both of an ethylene-based polymer (e1) and a polypropylene (z1) as the propylene-based polymer (P1). When the functional layer contains the polypropylene (z1), the functional layer also contains the propylene-based polymer (P1) other than the polypropylene (z1). When a twin capillary rheometer is used, the functional layer has an elongation rate of 60 to 100 s calculated by the Cogswell method from measurement data at a temperature of 240° C. of the functional layer. -1 The elongation viscosity of the functional layer at the elongation speed may be 10,000 Pa·s or more, and the elongation speed may be 50 to 70 s -1 The elongational viscosity of the functional layer at may be 10,000 Pa·s or more.

[0074] The elongation rate of 60 to 100 s was calculated by the Cogswell method from the measurement data of polypropylene (z1) at a temperature of 240°C using a twin capillary rheometer. -1 The extensional viscosity (minimum value of extensional viscosity) of the polypropylene (z1) at is preferably 10,000 Pa·s or more. In other words, it is preferably 60 to 100 s. -1 In the entire elongation rate range, the elongation viscosity of the polypropylene (z1) is preferably 10,000 Pa·s or more. Temperature 240℃, extension speed 60~100s -1 The extensional viscosity of the polypropylene (z1) at this point may be, for example, any one of 10100 Pa·s or more and 10200 Pa·s or more. Polypropylene (z1) having an extensional viscosity equal to or greater than the lower limit tends to have a high melt tension (in this specification, polypropylene having such a high melt tension is sometimes referred to as "high melt tension polypropylene"). A laminate film having a functional layer containing such a polypropylene (z1) having a high melt tension (high melt tension polypropylene) can more easily adjust the extensional viscosity to a desired value. That is, a laminate film having a functional layer containing such a polypropylene (z1) having a high melt tension can more easily suppress drawdown during heat molding, and can more easily increase formability during heat molding.

[0075] The upper limit of the extensional viscosity of the polypropylene (z1) is not particularly limited. In order to more easily realize the intended laminated film, the extensional viscosity (maximum value of extensional viscosity) of the polypropylene (z1) is preferably 30,000 Pa·s or less. That is, the upper limit of the extensional viscosity of the polypropylene (z1) at an extension rate of 60 to 100 s calculated by the Cogswell method from the measurement data of the polypropylene (z1) at a temperature of 240°C using a twin capillary rheometer is preferably 30,000 Pa·s or less. -1 The extensional viscosity (maximum value of extensional viscosity) of the polypropylene (z1) at 200° C. is preferably 30,000 Pa·s or less. In other words, it is preferably 60 to 100 s. -1 In the entire elongation rate range, the elongation viscosity of the polypropylene (z1) is preferably 30,000 Pa·s or less.

[0076] The polypropylene (z1) having the above-mentioned extensional viscosity is preferably a metallocene-catalyzed high melt tension polypropylene (HMSPP).

[0077] The elongation rate of 60 to 100 s calculated by the Cogswell method from the measurement data of the ethylene polymer (e1) at a temperature of 240° C. when a twin capillary rheometer is used. -1 The extensional viscosity (minimum value of extensional viscosity) of the ethylene polymer (e1) at is preferably 10,000 Pa·s or more. In other words, it is preferably 60 to 100 s. -1 In the entire extension rate range, the extensional viscosity of the ethylene polymer (e1) is preferably 10,000 Pa·s or more. Temperature 240℃, extension speed 60~100s -1 In this case, the extensional viscosity of the ethylene polymer (e1) may be, for example, any one of 10100 Pa·s or more and 10200 Pa·s or more. The ethylene polymer (e1) having the extensional viscosity equal to or higher than the lower limit tends to have a high melt tension. The laminate film having a functional layer containing the ethylene polymer (e1) having such a high melt tension can more easily adjust the extensional viscosity to a desired value. That is, the laminate film having a functional layer containing the ethylene polymer (e1) having such a high melt tension can more easily suppress drawdown during heat molding and can more easily improve the moldability during heat molding.

[0078] The upper limit of the extensional viscosity of the ethylene polymer (e1) is not particularly limited. In terms of making it easier to realize the intended laminated film, the extensional viscosity (maximum value of extensional viscosity) of the ethylene polymer (e1) is preferably 30,000 Pa·s or less. That is, the upper limit of the extensional viscosity of the ethylene polymer (e1) is preferably 30,000 Pa·s or less, calculated by the Cogswell method from the measurement data of the ethylene polymer (e1) at a temperature of 240° C. when a twin capillary rheometer is used. -1 The extensional viscosity (maximum value of extensional viscosity) of the ethylene polymer (e1) at this temperature is preferably 30,000 Pa·s or less. In other words, it is preferably 60 to 100 s. -1 In the entire extension rate range, the extensional viscosity of the ethylene polymer (e1) is preferably 30000 Pa·s or less.

[0079] The ethylene polymer (e1) having the above-mentioned extensional viscosity is preferably one or more selected from the group consisting of low density polyethylene (LDPE), linear low density polyethylene (LLDPE) and metallocene-catalyzed linear low density polyethylene (mLLDPE).

[0080] The extensional viscosity of the polypropylene (z1) and the ethylene polymer (e1) can be easily and accurately measured, for example, by using granular materials (particles of polypropylene (z1) and particles of the ethylene polymer (e1)) having a particle size of about 1 to 10 mm. Except for this, the extensional viscosity of the polypropylene (z1) and the ethylene polymer (e1) may be measured, for example, by the same method as that for the extensional viscosity of the laminate film described above.

[0081] In terms of making it easier to adjust the extensional viscosity of the laminated film to a desired value, it is preferable that the functional layer contains, as the propylene-based polymer (P1), either one or both of a propylene-ethylene block copolymer and a homopolypropylene, and further contains either one or both of an ethylene-based polymer (e1) and a polypropylene (z1) as the propylene-based polymer (P1), the ethylene-based polymer (e1) being one or more selected from the group consisting of low-density polyethylene, linear low-density polyethylene, and metallocene-catalyzed linear low-density polyethylene, the polypropylene (z1) being metallocene-catalyzed high melt tension polypropylene, and when the functional layer contains polypropylene (z1) (i.e., metallocene-catalyzed high melt tension polypropylene), it also contains a propylene-based polymer (P1) other than polypropylene (z1).

[0082] The functional layer containing a polyolefin-based resin may contain only a polyolefin-based resin (i.e., it may consist of a polyolefin-based resin), or it may contain a polyolefin-based resin and other components (sometimes referred to in this specification as “other component (1)”) other than the polyolefin-based resin (i.e., it may consist of a polyolefin-based resin and the other components).

[0083] The other component (1) contained in the functional layer is not particularly limited and can be selected arbitrarily depending on the purpose, and may be, for example, either a resin component or a non-resin component. The other component (1) which is a resin component is a resin other than a polyolefin-based resin, and is preferably a thermoplastic resin. The other component (1) which is a resin component may be a homopolymer which is a polymer of one type of monomer, or a copolymer which is a polymer of two or more types of monomers.

[0084] Examples of the other component (1) that is a non-resin component include additives known in the art. Examples of the additives include pigments, antifogging agents, antiblocking agents, antioxidants, antistatic agents, crystal nucleating agents, inorganic particles, viscosity reducers, thickeners, heat stabilizers, lubricants, infrared absorbers, and ultraviolet absorbers.

[0085] The functional layer may contain only one type of other component (1) or two or more types. When there are two or more types, the combination and ratio thereof can be arbitrarily selected depending on the purpose.

[0086] In a functional layer containing a polyolefin-based resin, the ratio of the polyolefin-based resin content (parts by mass) to the total mass (parts by mass) of the functional layer ([polyolefin-based resin content (parts by mass) in functional layer)] / [total mass (parts by mass) in functional layer)]×100) is preferably 80% by mass or more, more preferably 90% by mass or more, and may be, for example, any of 93% by mass or more, 96% by mass or more, and 99% by mass or more. When the ratio is equal to or greater than the lower limit, the effect of suppressing drawdown during heat molding of the laminated film is higher, and the formability of the laminated film during heat molding is higher. On the other hand, the proportion is 100% by mass or less. The above ratio is usually the same as the ratio of the polyolefin-based resin content to the total content (parts by mass) of components that do not vaporize at room temperature in the functional layer-forming composition described below ([polyolefin-based resin content (parts by mass) in the functional layer-forming composition)] / [total content (parts by mass) of components that do not vaporize at room temperature in the functional layer-forming composition]×100).

[0087] In this specification, "room temperature" means a temperature that is neither particularly cooled nor heated, that is, an ordinary temperature, and examples thereof include temperatures of 15 to 25°C.

[0088] When the functional layer contains a propylene-based polymer (P1) and an ethylene-based polymer (e1), or contains two or more kinds of propylene-based polymers (P1), the ratio of the total content (parts by mass) of the propylene-based polymer (P1) and the ethylene-based polymer (e1) to the total mass (parts by mass) of the functional layer (([content (parts by mass) of the propylene-based polymer (P1) in the functional layer)] + [content (parts by mass) of the ethylene-based polymer (e1) in the functional layer)] / [total mass (parts by mass) of the functional layer)] × 100) is preferably 80% by mass or more, more preferably 90% by mass or more, and may be, for example, any one of 93% by mass or more, 96% by mass or more, and 99% by mass or more. When the ratio is equal to or more than the lower limit, the effect of suppressing drawdown during heat molding of the laminated film is higher, and the moldability of the laminated film during heat molding is higher. On the other hand, the proportion is 100% by mass or less. The above ratio is usually the same as the ratio of the total content (parts by mass) of the propylene-based polymer (P1) and the ethylene-based polymer (e1) to the total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming a functional layer described below (([content (parts by mass) of propylene-based polymer (P1) in the composition for forming a functional layer)] + [content (parts by mass) of ethylene-based polymer (e1) in the composition for forming a functional layer)]) / [total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming a functional layer)] × 100). When the functional layer or the composition for forming a functional layer does not contain the ethylene polymer (e1), the content of the ethylene polymer (e1) in the functional layer or the composition for forming a functional layer is 0 part by mass.

[0089] When the functional layer contains either or both of polypropylene (z1) and ethylene-based polymer (e1), the ratio of the total content of polypropylene (z1) and ethylene-based polymer (e1) to the total mass of the functional layer (([content of polypropylene (z1) in the functional layer (parts by mass)] + [content of ethylene-based polymer (e1) in the functional layer (parts by mass)]) / [total mass of the functional layer (parts by mass)] × 100) is preferably 3 mass% or more, and may be, for example, any of 9 mass% or more and 15 mass% or more. When the ratio is equal to or more than the lower limit, the effect of suppressing drawdown during heat molding of the laminate film is increased, and the formability of the laminate film during heat molding is increased. On the other hand, the upper limit of the ratio is not particularly limited. For example, the ratio is preferably 25% by mass or less in order to further suppress the excessive use of polypropylene (z1) or ethylene polymer (e1). The above ratio is usually the same as the ratio of the total content (parts by mass) of polypropylene (z1) and ethylene-based polymer (e1) to the total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming a functional layer described below (([content (parts by mass) of polypropylene (z1) in the composition for forming a functional layer)] + [content (parts by mass) of ethylene-based polymer (e1) in the composition for forming a functional layer)]) / [total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming a functional layer)] × 100). Here, when the functional layer or the composition for forming a functional layer does not contain polypropylene (z1), the content of polypropylene (z1) in the functional layer or the composition for forming a functional layer is 0 parts by mass. When the functional layer or the composition for forming a functional layer does not contain an ethylene-based polymer (e1), the content of the ethylene-based polymer (e1) in the functional layer or the composition for forming a functional layer is 0 parts by mass.

[0090] As explained above, when the extensional viscosity of the polypropylene (z1) is 10000 Pa s or more and the extensional viscosity of the ethylene polymer (e1) is 10000 Pa s or more, it is particularly preferable that the ratio of the total content of the polypropylene (z1) and the ethylene polymer (e1) to the total mass of the functional layer is within any of the above-mentioned numerical ranges. In such a case, the effect of suppressing drawdown during heat molding of the laminate film is particularly high, and the moldability of the laminate film during heat molding is particularly high.

[0091] The content of the other component (1) in the functional layer can be appropriately adjusted depending on the type of the other component (1). For example, when the other component (1) is a pigment, the ratio of the pigment content in the functional layer to the total mass of the functional layer ([pigment content in functional layer (parts by mass)] / [total mass of functional layer (parts by mass)]×100) is preferably 1 to 12 mass%, and may be, for example, any of 1 to 7 mass% and 6 to 12 mass%. When the ratio is equal to or greater than the lower limit, the effect obtained by using the pigment is enhanced. When the ratio is equal to or less than the upper limit, excessive use of the pigment is further suppressed. The above ratio is usually the same as the ratio of the pigment content to the total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming a functional layer described below ([pigment content (parts by mass) in the composition for forming a functional layer)] / [total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming a functional layer] × 100).

[0092] For example, when the other component (1) is a component other than a pigment, the ratio of the content of the other component (1) (component other than pigment) in the functional layer to the total mass of the functional layer ([content of the other component (1) in the functional layer (parts by mass)] / [total mass of the functional layer (parts by mass)]×100) is preferably 0.1 to 20% by mass, more preferably 0.1 to 10% by mass, and may be, for example, any one of 0.1 to 7% by mass, 0.1 to 4% by mass, and 0.1 to 1% by mass. When the ratio is equal to or greater than the lower limit, the effect obtained by using the other component (1) is enhanced. When the ratio is equal to or less than the upper limit, excessive use of the other component (1) is further suppressed.

[0093] The functional layer may be one layer (single layer) or two or more layers. When the functional layer is made up of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited as long as it does not impair the effects of the present invention.

[0094] In this specification, not limited to the case of functional layers, "multiple layers may be the same or different from each other" means "all layers may be the same, all layers may be different, or only some layers may be the same", and further, "multiple layers are different from each other" means "at least one of the constituent materials and thicknesses of each layer is different from each other".

[0095] In this specification, not only in the case of functional layers, but also in the case where, for example, layers of the same type consisting of a single layer are arranged apart from each other without being directly laminated in a laminate film, these layers are not regarded as consisting of two layers (multiple layers), but are regarded as layers consisting of a single layer arranged in different positions in the laminate film. Similarly, if a layer consisting of two layers and a layer consisting of one layer are both the same type of layer and are positioned apart from each other without being directly laminated in the laminate film, these layers are not considered to be composed of three layers, but rather the layer consisting of two layers and the layer consisting of one layer are considered to be positioned in different positions in the laminate film. The same applies to other combinations of the number of layers.

[0096] From the viewpoint of simplifying the structure of the laminated film, the functional layer is preferably made of one layer.

[0097] The laminated film may have functional layers at multiple locations (two or more locations) in the thickness direction (two or more functional layers), and in that case, it is preferable that the laminated film has a pair of functional layers and has a layer other than the functional layer between the pair of functional layers. In this case, a preferable layer other than the functional layer is, for example, an oxygen barrier layer described later. In this way, in a laminated film having functional layers at multiple locations, the effect obtained by having the functional layer is enhanced. And, in a laminated film (for example, laminated film 1 shown in FIG. 2 and laminated film 2 shown in FIG. 3) having a pair of functional layers (for example, first functional layer 111 and second functional layer 112 shown in FIG. 2 and FIG. 3) and a layer other than the functional layer provided between them (for example, oxygen barrier layer 12 shown in FIG. 2 and FIG. 3), the effect obtained by having the functional layer and the layer other than the functional layer is enhanced.

[0098] When the laminated film has functional layers at two or more locations in the thickness direction, these two or more functional layers may be the same as or different from each other. Here, "the functional layers at two or more locations may be the same as or different from each other" means "all the functional layers may be the same, all the functional layers may be different, or only some of the functional layers may be the same", and further, "the functional layers are different from each other" means "at least one of the constituent materials and thicknesses of the functional layers is different from each other".

[0099] The thickness of the functional layer is preferably 100 to 800 μm, more preferably 100 to 600 μm, and even more preferably 100 to 400 μm. When the thickness of the functional layer is equal to or greater than the lower limit, the effect of suppressing drawdown during heat molding of the laminated film is increased, and the formability of the laminated film during heat molding is improved. When the thickness of the functional layer is equal to or less than the upper limit, the thickness of the functional layer is further prevented from becoming excessive. Here, "thickness of the functional layer" means the thickness of the entire functional layer; for example, the thickness of a functional layer consisting of multiple layers means the total thickness of all layers that make up the functional layer.

[0100] In this specification, not only in the case of a functional layer, but also in the case where a laminate film has layers of the same type at multiple locations in its thickness direction, the "thickness" of a layer means the thickness of that layer at one location, unless otherwise specified.

[0101] The ratio of the thickness of the functional layer to the thickness of the laminated film is preferably 15 to 60%, more preferably 15 to 55%, and even more preferably 15 to 50%. When the ratio is equal to or greater than the lower limit, the effect of suppressing drawdown during heat molding of the laminated film is increased, and the formability of the laminated film during heat molding is improved. When the ratio is equal to or less than the upper limit, the thickness of the functional layer is further prevented from becoming excessive.

[0102] <Oxygen barrier layer> The oxygen barrier layer (for example, oxygen barrier layer 12 shown in Figures 2 and 3) imparts oxygen barrier properties (in other words, the property of suppressing the permeation of oxygen gas) to the laminate film (for example, laminate film 1 shown in Figure 2 and laminate film 2 shown in Figure 3).

[0103] In the oxygen barrier layer, the ratio of the total content of one or more components contained in the oxygen barrier layer, which will be described later, to the total mass of the oxygen barrier layer does not exceed 100 mass %. Similarly, in the composition for forming an oxygen barrier layer described later, the ratio of the total content of one or more of the components contained in the composition for forming an oxygen barrier layer described later to the total mass of the composition for forming an oxygen barrier layer does not exceed 100 mass%.

[0104] The oxygen barrier layer is preferably a resin layer containing an oxygen barrier resin, and more preferably contains an ethylene-vinyl alcohol copolymer (EVOH, also known as saponified ethylene-vinyl acetate copolymer). When the oxygen barrier layer contains an ethylene-vinyl alcohol copolymer, the oxygen barrier property of the laminated film is improved.

[0105] In the ethylene-vinyl alcohol copolymer contained in the oxygen barrier layer, the ratio of the amount (mol) of structural units derived from ethylene to the total amount (mol) of structural units (sometimes referred to as the "copolymerization ratio of ethylene" in this specification) is preferably 50 mol% or less, and may be, for example, any one of 45 mol% or less, 40 mol% or less, 35 mol% or less, and 30 mol% or less. When the ratio (copolymerization ratio of ethylene) is equal to or less than the upper limit, the ratio of the amount (mol) of structural units considered to be derived from vinyl alcohol becomes high, and the oxygen barrier property of the oxygen barrier layer and the laminated film becomes higher. On the other hand, the lower limit of the ratio (the copolymerization ratio of ethylene) is not particularly limited. For example, an ethylene-vinyl alcohol copolymer having the ratio of 25 mol % or more can be more easily obtained or produced. In one embodiment, the ratio (the copolymerization ratio of ethylene) may be, for example, any one of 25 to 50 mol%, 25 to 45 mol%, 25 to 40 mol%, 25 to 35 mol%, and 25 to 30 mol%, although these are only examples of the ratio (the copolymerization ratio of ethylene).

[0106] The melting point of the ethylene-vinyl alcohol copolymer contained in the oxygen barrier layer is preferably 150° C. or higher, and may be, for example, either 170° C. or higher or 180° C. or higher. Since an ethylene-vinyl alcohol copolymer having a melting point of 150° C. or higher has higher heat resistance, the oxygen barrier layer containing such an ethylene-vinyl alcohol copolymer also has higher heat resistance, and the laminate film also has higher heat resistance. On the other hand, in terms of improving the formability of the laminated film, the melting point of the ethylene-vinyl alcohol copolymer is preferably 200° C. or lower. In one embodiment, the melting point of the ethylene-vinyl alcohol copolymer may be, for example, any one of 150 to 200° C., 170 to 200° C., and 180 to 200° C. However, these are only examples of the melting point of the ethylene-vinyl alcohol copolymer.

[0107] The oxygen barrier layer may or may not further contain polyvinylidene chloride (PVDC) as an oxygen barrier resin in addition to the ethylene-vinyl alcohol copolymer. When the oxygen barrier layer contains the ethylene-vinyl alcohol copolymer and polyvinylidene chloride, the oxygen barrier property of the laminated film is further improved.

[0108] The oxygen barrier layer may contain only an oxygen barrier resin (e.g., an ethylene-vinyl alcohol copolymer, or an ethylene-vinyl alcohol copolymer and polyvinylidene chloride) (i.e., it may consist of an oxygen barrier resin), or it may contain an oxygen barrier resin and other components (sometimes referred to in this specification as “other component (4)”) (i.e., it may consist of an oxygen barrier resin and the other components).

[0109] The other component (4) contained in the oxygen barrier layer is not particularly limited and can be selected arbitrarily depending on the purpose, and may be, for example, either a resin component or a non-resin component. The other component (4) which is a resin component is a resin other than an oxygen barrier resin, and is preferably a thermoplastic resin. The other component (4) which is a resin component may be a homopolymer which is a polymer of one type of monomer, or a copolymer which is a polymer of two or more types of monomers. Examples of the other component (4) which is a non-resin component include the same additives as those listed above as the other component (1) contained in the functional layer.

[0110] The oxygen barrier layer may contain only one type of other component (4) or two or more types. When there are two or more types, the combination and ratio thereof can be selected arbitrarily depending on the purpose.

[0111] In the oxygen barrier layer, the ratio of the content (parts by mass) of the oxygen barrier resin to the total mass (parts by mass) of the oxygen barrier layer ([content (parts by mass) of the oxygen barrier resin in the oxygen barrier layer)] / [total mass (parts by mass) of the oxygen barrier layer]×100) is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, and may be, for example, any one of 80% by mass or more, 90% by mass or more, 95% by mass or more, 97% by mass or more, and 99% by mass or more. When the ratio is equal to or more than the lower limit, the oxygen barrier property of the oxygen barrier layer and the laminate film is further improved. On the other hand, the proportion is 100% by mass or less. The ratio is usually the same as the ratio of the content of the oxygen barrier resin to the total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming an oxygen barrier layer described below ([content of the oxygen barrier resin in the composition for forming an oxygen barrier layer (parts by mass)] / [total content of components that do not vaporize at room temperature in the composition for forming an oxygen barrier layer (parts by mass)]×100).

[0112] The ratio of the ethylene-vinyl alcohol copolymer content to the oxygen barrier resin content in the oxygen barrier layer ([ethylene-vinyl alcohol copolymer content in oxygen barrier layer (parts by mass)] / [oxygen barrier resin content in oxygen barrier layer (parts by mass)]×100) is preferably 85% by mass or more, more preferably 90% by mass or more, and may be, for example, any one of 95% by mass or more, 97% by mass or more, and 99% by mass or more. When the ratio is equal to or more than the lower limit, the oxygen barrier property of the oxygen barrier layer and the laminate film is improved. On the other hand, the proportion is 100% by mass or less. The ratio is usually the same as the ratio of the content of the ethylene-vinyl alcohol copolymer to the content (parts by mass) of the oxygen barrier resin in the composition for forming an oxygen barrier layer described below ([content (parts by mass) of the ethylene-vinyl alcohol copolymer in the composition for forming an oxygen barrier layer] / [content (parts by mass) of the oxygen barrier resin in the composition for forming an oxygen barrier layer]×100).

[0113] The oxygen barrier layer may be composed of one layer (single layer) or may be composed of two or more layers. When the oxygen barrier layer is composed of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited as long as it does not impair the effects of the present invention.

[0114] The thickness of the oxygen barrier layer is preferably 5 to 100 μm, more preferably 10 to 70 μm, and even more preferably 15 to 45 μm. When the thickness of the oxygen barrier layer is equal to or more than the lower limit, the oxygen barrier properties of the oxygen barrier layer and the laminated film are improved. When the thickness of the oxygen barrier layer is equal to or less than the upper limit, the oxygen barrier layer is prevented from becoming excessively thick. Here, the "thickness of the oxygen barrier layer" means the thickness of the entire oxygen barrier layer. For example, the thickness of an oxygen barrier layer consisting of multiple layers means the total thickness of all layers that make up the oxygen barrier layer.

[0115] The ratio of the thickness of the oxygen barrier layer to the thickness of the laminated film is preferably 1 to 15%, more preferably 1 to 12%, and even more preferably 1 to 9%. When the ratio is equal to or greater than the lower limit, the oxygen barrier properties of the oxygen barrier layer and the laminated film are improved. When the ratio is equal to or less than the upper limit, the oxygen barrier layer is prevented from becoming excessively thick.

[0116] It is preferable that the laminated film has two or more functional layers in the thickness direction, and an oxygen barrier layer is provided between a pair of the functional layers. In such a laminated film, the effect obtained by providing the functional layer and the oxygen barrier layer is enhanced.

[0117] <Inner layer> The laminate film of the present embodiment may further include an inner layer (for example, inner layer 13 shown in FIG. 3) as one of the outermost layers in addition to the functional layer and the oxygen barrier layer. The inner layer imparts formability, impact resistance, and sealability to the laminate film. The inner layer is the outermost layer on one side of the laminate film, and is disposed on the outermost side on one side in the lamination direction of the layers constituting the laminate film. The inner layer functions as a sealant layer when a package, which will be described later, is produced using the laminated film.

[0118] In the inner layer, the ratio of the total content of one or more components contained in the inner layer, which will be described later, to the total mass of the inner layer does not exceed 100 mass %. Similarly, in the composition for forming an inner layer described later, the ratio of the total content of one or more components contained in the composition for forming an inner layer described later to the total mass of the composition for forming an inner layer does not exceed 100 mass%.

[0119] The inner layer is preferably a resin layer containing a resin, and more preferably contains a polyolefin-based resin. The polyolefin resin contained in the inner layer may be, for example, the same as the polyolefin resin contained in the functional layer. More specifically, the polyolefin resin contained in the inner layer may be, for example, an ethylene polymer (in this specification, the ethylene polymer contained in the inner layer may be particularly referred to as "ethylene polymer (e2)"), a propylene polymer (in this specification, the propylene polymer contained in the inner layer may be particularly referred to as "propylene polymer (P2)"), etc. The inner layer containing a polyolefin resin not only imparts formability, impact resistance, and sealability to the laminate film, but also further improves the effect of suppressing drawdown during heat molding of the laminate film. Furthermore, by making polyolefin the main constituent material (main component) of the multiple resin layers of the laminate film, it is advantageous in improving the recyclability of the laminate film.

[0120] The ethylene polymer (e2) and the propylene polymer (P2) contained in the inner layer are the same as the ethylene polymer (e1) and the propylene polymer (P1) contained in the functional layer, respectively. In this specification, among the propylene polymers (P2) contained in the inner layer, polypropylene may be particularly referred to as "polypropylene (z2)".

[0121] For example, the extensional viscosities of polypropylene (z2) and the ethylene polymer (e2) are similar to those of polypropylene (z1) and the ethylene polymer (e1), respectively. More specifically, for example, the elongation rate of 60 to 100 s calculated by the Cogswell method from the measurement data of polypropylene (z2) at a temperature of 240° C. when a twin capillary rheometer is used. -1 The extensional viscosity (minimum value of extensional viscosity) of the polypropylene (z2) at is preferably 10000 Pa·s or more. The polypropylene (z2) having such an extensional viscosity is preferably a metallocene-catalyzed high melt tension polypropylene (HMSPP). More specifically, for example, when a twin capillary rheometer is used, the elongation rate is calculated by the Cogswell method from the measurement data of the ethylene polymer (e2) at a temperature of 240° C. -1 The ethylene polymer (e2) preferably has an extensional viscosity (minimum value of extensional viscosity) of 10,000 Pa s or more at this temperature. The ethylene polymer (e2) having such an extensional viscosity is preferably one or more selected from the group consisting of low density polyethylene (LDPE), linear low density polyethylene (LLDPE) and metallocene-catalyzed linear low density polyethylene (mLLDPE). As described above, the inner layer imparts formability, impact resistance, and sealability to the laminate film. In addition, since the inner layer contains the ethylene-based polymer (e2) or the propylene-based polymer (P2), the same effects as those obtained by the functional layer containing the ethylene-based polymer (e1) or the propylene-based polymer (P1) can be obtained.

[0122] The extensional viscosities of the polypropylene (z2) and the ethylene polymer (e2) can be measured in the same manner as in the case of the extensional viscosities of the polypropylene (z1) and the ethylene polymer (e1), respectively.

[0123] The melt flow rate and density of the propylene polymer (P2) are similar to those of the propylene polymer (P1), respectively.

[0124] The propylene-based polymer (P2) contained in the inner layer and the propylene-based polymer (P1) contained in the functional layer may be the same as or different from each other. The ethylene polymer (e2) contained in the inner layer and the ethylene polymer (e1) contained in the functional layer may be the same as or different from each other.

[0125] For example, the resin contained in the inner layer may be only one type, or may be two or more types. When two or more types are contained, the combination and ratio thereof can be arbitrarily selected depending on the purpose. For example, the inner layer may contain one or more types of ethylene-based polymers (e2) and not contain a propylene-based polymer (P2), may contain one or more types of propylene-based polymers (P2) and not contain an ethylene-based polymer (e2), or may contain both one or more types of ethylene-based polymers (e2) and one or more types of propylene-based polymers (P2).

[0126] In terms of imparting formability, impact resistance and sealability to the laminated film and making it easier to adjust the elongational viscosity of the laminated film to a desired value, the inner layer preferably contains a propylene-based polymer (P2), more preferably contains a propylene-based polymer (P2) and an ethylene-based polymer (e2), or contains two or more kinds of propylene-based polymers (P2). It is particularly preferable that the inner layer contains one or two or more kinds of propylene-based polymers (P2) and an ethylene-based polymer (e2), and when two or more kinds of propylene-based polymers (P2) are contained, at least one of them is polypropylene (z2), or contains polypropylene (z2) and a propylene-based polymer (P2) other than polypropylene (z2). That is, the inner layer contains a propylene-based polymer (P2) and further contains one or both of an ethylene-based polymer (e2) and a polypropylene (z2) as the propylene-based polymer (P2). When the inner layer contains the polypropylene (z2), it is particularly preferable that the inner layer also contains the propylene-based polymer (P2) other than the polypropylene (z2).

[0127] In terms of making it easier to adjust the elongational viscosity of the laminated film to a desired value, the propylene-based polymer (P2) (e.g., polypropylene (z2) and a propylene-based polymer (P2) other than polypropylene (z2)) is preferably either one or both of a propylene-ethylene block copolymer (bPP) and a homopolypropylene (hPP).

[0128] In terms of particularly improving the effect of suppressing drawdown during heat molding of the laminate film and particularly improving the formability of the laminate film during heat molding, when the inner layer contains the propylene-based polymer (P2) and the ethylene-based polymer (e2), the melt flow rates of the propylene-based polymer (P2) and the ethylene-based polymer (e2) are preferably both in any of the above-mentioned numerical ranges. For example, the melt flow rates of the propylene-based polymer (P2) and the ethylene-based polymer (e2) are preferably 3 g / 10 min or less.

[0129] From the viewpoint of making it easier to adjust the extensional viscosity of the laminated film to a desired value, it is preferable that the inner layer contains, as the propylene-based polymer (P2), either one or both of a propylene-ethylene block copolymer and a homopolypropylene, and further contains either one or both of an ethylene-based polymer (e2) and a polypropylene (z2) as the propylene-based polymer (P2), the ethylene-based polymer (e2) being one or more selected from the group consisting of low-density polyethylene, linear low-density polyethylene, and metallocene-catalyzed linear low-density polyethylene, the polypropylene (z2) being metallocene-catalyzed high melt tension polypropylene, and when the inner layer contains polypropylene (z2) (i.e., metallocene-catalyzed high melt tension polypropylene), it also contains a propylene-based polymer (P2) other than polypropylene (z2).

[0130] The inner layer containing a polyolefin-based resin may contain only a polyolefin-based resin (i.e., it may consist of a polyolefin-based resin), or it may contain a polyolefin-based resin and other components (sometimes referred to in this specification as “other component (2)”) other than the polyolefin-based resin (i.e., it may consist of a polyolefin-based resin and the other components).

[0131] The other component (2) contained in the inner layer is not particularly limited and can be selected arbitrarily depending on the purpose. For example, it may be either a resin component or a non-resin component, and examples thereof include the same as the other component (1) contained in the functional layer.

[0132] The other component (2) contained in the inner layer may be only one type, or may be two or more types. When there are two or more types, the combination and ratio thereof can be arbitrarily selected depending on the purpose.

[0133] In an inner layer containing a polyolefin resin, the ratio of the polyolefin resin content (parts by mass) to the total mass (parts by mass) of the inner layer ([polyolefin resin content (parts by mass) of the inner layer)] / [total mass (parts by mass) of the inner layer]×100) is preferably 80% by mass or more, more preferably 90% by mass or more, and may be, for example, any one of 95% by mass or more, 97% by mass or more, and 99% by mass or more. When the ratio is equal to or more than the lower limit, the formability, impact resistance, and sealability of the laminate film are improved, and the effect of suppressing drawdown during heat molding of the laminate film is improved, thereby improving the formability of the laminate film during heat molding. On the other hand, the proportion is 100% by mass or less. The ratio is usually the same as the ratio of the polyolefin resin content to the total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming the inner layer described below ([content of polyolefin resin in the composition for forming the inner layer (parts by mass)] / [total content of components that do not vaporize at room temperature in the composition for forming the inner layer (parts by mass)]×100).

[0134] When the inner layer contains a propylene-based polymer (P2) and an ethylene-based polymer (e2), or contains two or more kinds of propylene-based polymers (P2), the ratio of the total content (parts by mass) of the propylene-based polymer (P2) and the ethylene-based polymer (e2) to the total mass (parts by mass) of the inner layer (([content (parts by mass) of the propylene-based polymer (P2) in the inner layer)] + [content (parts by mass) of the ethylene-based polymer (e2) in the inner layer)]) / [total mass (parts by mass) of the inner layer] × 100) is preferably 80% by mass or more, more preferably 90% by mass or more, and may be, for example, any one of 95% by mass or more, 97% by mass or more, and 99% by mass or more. When the ratio is equal to or more than the lower limit, the formability, impact resistance, and sealability of the laminate film are improved, and the effect of suppressing drawdown during heat molding of the laminate film is improved, and the formability of the laminate film during heat molding is improved. On the other hand, the proportion is 100% by mass or less. The ratio is usually the same as the ratio of the total content (parts by mass) of the propylene-based polymer (P2) and the ethylene-based polymer (e2) to the total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming an inner layer described later (([content (parts by mass) of the propylene-based polymer (P2) in the composition for forming an inner layer)] + [content (parts by mass) of the ethylene-based polymer (e2) in the composition for forming an inner layer)]) / [total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming an inner layer)] × 100). When the inner layer or the composition for forming an inner layer does not contain the ethylene polymer (e2), the content of the ethylene polymer (e2) in the inner layer or the composition for forming an inner layer is 0 part by mass.

[0135] When the inner layer contains either one or both of polypropylene (z2) and ethylene-based polymer (e2), the ratio of the total content of polypropylene (z2) and ethylene-based polymer (e2) to the total mass of the inner layer (([content of polypropylene (z2) in the inner layer (parts by mass)] + [content of ethylene-based polymer (e2) in the inner layer (parts by mass)]) / [total mass of the inner layer (parts by mass)] × 100) is preferably 5 mass% or more, and may be, for example, 10 mass% or more or 15 mass% or more. When the ratio is equal to or more than the lower limit, the formability, impact resistance, and sealability of the laminate film are improved, and the effect of suppressing drawdown during heat molding of the laminate film is improved, and the formability of the laminate film during heat molding is improved. On the other hand, the upper limit of the ratio is not particularly limited. For example, the ratio is preferably 25% by mass or less, in order to further suppress the excessive use of polypropylene (z2) or ethylene polymer (e2). The ratio is usually the same as the ratio of the total content (parts by mass) of polypropylene (Z2) and ethylene-based polymer (E2) to the total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming an inner layer described later (([content (parts by mass) of polypropylene (Z2) in the composition for forming an inner layer)] + [content (parts by mass) of ethylene-based polymer (E2) in the composition for forming an inner layer)]) / [total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming an inner layer)] × 100). Here, when the inner layer or composition for forming an inner layer does not contain polypropylene (z2), the content of polypropylene (z2) in the inner layer or composition for forming an inner layer is 0 parts by mass. When the inner layer or composition for forming an inner layer does not contain an ethylene-based polymer (e2), the content of the ethylene-based polymer (e2) in the inner layer or composition for forming an inner layer is 0 parts by mass.

[0136] As explained above, when the extensional viscosity of the polypropylene (z2) is 10000 Pa s or more and the extensional viscosity of the ethylene polymer (e2) is 10000 Pa s or more, it is particularly preferable that the ratio of the total content of the polypropylene (z2) and the ethylene polymer (e2) to the total mass of the inner layer is in any of the above-mentioned numerical ranges. In such a case, in addition to the improved formability, impact resistance and sealability of the laminate film, the effect of suppressing drawdown during heat molding of the laminate film is particularly high, and the formability of the laminate film during heat molding is particularly high.

[0137] The content of the other component (2) in the inner layer can be appropriately adjusted depending on the type of the other component (2). For example, in the inner layer, the ratio of the content of the other component (2) to the total mass of the inner layer ([content of the other component (2) in the inner layer (parts by mass)] / [total mass of the inner layer (parts by mass)]×100) is preferably 0.1 to 20% by mass, more preferably 0.1 to 10% by mass, and may be, for example, any one of 0.1 to 5% by mass, 0.1 to 3% by mass, and 0.1 to 1% by mass. When the ratio is equal to or greater than the lower limit, the effect obtained by using the other component (2) is enhanced. When the ratio is equal to or less than the upper limit, excessive use of the other component (2) is further suppressed.

[0138] The inner layer may be one layer (single layer) or two or more layers. When the inner layer is made up of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited as long as it does not impair the effects of the present invention.

[0139] From the viewpoint of simplifying the structure of the laminated film, it is preferable that the inner layer consists of a single layer.

[0140] The thickness of the inner layer is preferably 50 to 400 μm, more preferably 60 to 300 μm, and even more preferably 70 to 200 μm. When the thickness of the inner layer is equal to or greater than the lower limit, the laminated film has higher moldability, impact resistance, and sealability, and the laminated film has higher drawdown suppression effect during heat molding, resulting in higher moldability during heat molding. When the thickness of the inner layer is equal to or less than the upper limit, the inner layer is more prevented from becoming excessively thick. Here, the "thickness of the inner layer" means the thickness of the entire inner layer. For example, the thickness of an inner layer made up of multiple layers means the total thickness of all layers that make up the inner layer.

[0141] The ratio of the thickness of the inner layer to the thickness of the laminated film is preferably 5 to 40%, more preferably 5 to 30%, and even more preferably 5 to 35%. When the ratio is equal to or greater than the lower limit, the laminated film has higher moldability, impact resistance, and sealability, and the laminated film has a higher effect of suppressing drawdown during heat molding, thereby improving the moldability of the laminated film during heat molding. When the ratio is equal to or less than the upper limit, the thickness of the inner layer is further prevented from becoming excessive.

[0142] <Outer layer> The laminated film of the present embodiment may further include an outer layer (for example, outer layer 14 shown in FIG. 3) as the other outermost layer in addition to the functional layer and the oxygen barrier layer. The outer layer imparts rigidity and heat resistance to the laminated film and improves the appearance of the laminated film. Furthermore, the outer layer has a function of protecting layers other than the outer layer that constitute the laminated film. The outer layer is the outermost layer of the other of the laminated films, and is disposed on the outermost side of the other in the lamination direction of the layers constituting the laminated film.

[0143] In the outer layer, the ratio of the total content of one or more components contained in the outer layer, which will be described later, to the total mass of the outer layer does not exceed 100 mass %. Similarly, in the composition for forming an outer layer described later, the ratio of the total content of one or more components contained in the composition for forming an outer layer described later to the total mass of the composition for forming an outer layer does not exceed 100 mass%.

[0144] The outer layer is preferably a resin layer containing a resin, and more preferably contains a polyolefin-based resin. The polyolefin resin contained in the outer layer may be, for example, the same as the polyolefin resin contained in the functional layer. More specifically, the polyolefin resin contained in the outer layer may be, for example, an ethylene polymer (in this specification, the ethylene polymer contained in the outer layer may be particularly referred to as "ethylene polymer (e3)"), a propylene polymer (in this specification, the propylene polymer contained in the outer layer may be particularly referred to as "propylene polymer (P3)"), etc. As described above, the outer layer containing a polyolefin resin not only imparts rigidity, heat resistance, excellent appearance, and protective properties to the layers other than the outer layer to the laminate film, but also further improves the effect of suppressing drawdown during heat molding of the laminate film, and by using polyolefin as the main constituent material (main component) of the multiple resin layers of the laminate film, it is advantageous in improving the recyclability of the laminate film.

[0145] The ethylene polymer (e3) and the propylene polymer (P3) contained in the outer layer are the same as the ethylene polymer (e1) and the propylene polymer (P1) contained in the functional layer, respectively. In this specification, among the propylene polymers (P3) contained in the outer layer, polypropylene may be particularly referred to as "polypropylene (z3)".

[0146] For example, the extensional viscosities of the polypropylene (z3) and the ethylene polymer (e3) are similar to those of the polypropylene (z1) and the ethylene polymer (e1), respectively. More specifically, for example, the elongation rate of 60 to 100 s calculated by the Cogswell method from the measurement data of polypropylene (z3) at a temperature of 240° C. when a twin capillary rheometer is used. -1 The extensional viscosity (minimum value of extensional viscosity) of the polypropylene (z3) at is preferably 10000 Pa·s or more. The polypropylene (z3) having such an extensional viscosity is preferably a metallocene-catalyzed high melt tension polypropylene (HMSPP). More specifically, for example, when a twin capillary rheometer is used, the elongation rate is calculated by the Cogswell method from the measurement data of the ethylene polymer (e3) at a temperature of 240° C. -1 The ethylene polymer (e3) preferably has an extensional viscosity (minimum value of extensional viscosity) of 10,000 Pa s or more at this temperature. The ethylene polymer (e3) having such an extensional viscosity is preferably one or more selected from the group consisting of low density polyethylene (LDPE), linear low density polyethylene (LLDPE) and metallocene-catalyzed linear low density polyethylene (mLLDPE). As described above, the outer layer imparts to the laminate film rigidity, heat resistance, excellent appearance, and a protective function for the layers other than the outer layer. In addition, by containing the ethylene-based polymer (e3) or the propylene-based polymer (P3), the same effects as those obtained by containing the ethylene-based polymer (e1) or the propylene-based polymer (P1) can be obtained.

[0147] The extensional viscosities of the polypropylene (z3) and the ethylene polymer (e3) can be measured in the same manner as in the case of the extensional viscosities of the polypropylene (z1) and the ethylene polymer (e1), respectively.

[0148] The melt flow rate and density of the propylene polymer (P3) are similar to those of the propylene polymer (P1), respectively.

[0149] The propylene-based polymer (P3) contained in the outer layer and the propylene-based polymer (P1) contained in the functional layer may be the same as or different from each other, and the propylene-based polymer (P3) contained in the outer layer and the propylene-based polymer (P2) contained in the inner layer may be the same as or different from each other. The ethylene-based polymer (e3) contained in the outer layer and the ethylene-based polymer (e1) contained in the functional layer may be the same as or different from each other, and the ethylene-based polymer (e3) contained in the outer layer and the ethylene-based polymer (e2) contained in the inner layer may be the same as or different from each other.

[0150] For example, the outer layer may contain only one type of resin, or two or more types. When the outer layer contains two or more types of resin, the combination and ratio thereof can be arbitrarily selected depending on the purpose. For example, the outer layer may contain one or more types of ethylene-based polymers (e3) and not contain a propylene-based polymer (P3), may contain one or more types of propylene-based polymers (P3) and not contain an ethylene-based polymer (e3), or may contain both one or more types of ethylene-based polymers (e3) and one or more types of propylene-based polymers (P3).

[0151] In addition to imparting rigidity, heat resistance, excellent appearance, and a protective function for layers other than the outer layer to the laminate film, the outer layer preferably contains a propylene-based polymer (P3), and more preferably contains a propylene-based polymer (P3) and an ethylene-based polymer (e3), or contains two or more kinds of propylene-based polymers (P3). In the case where the outer layer contains two or more kinds of propylene-based polymers (P3), it is particularly preferable that the outer layer contains one or two or more kinds of propylene-based polymers (P3) and an ethylene-based polymer (e3), and when the outer layer contains two or more kinds of propylene-based polymers (P3), at least one of them is polypropylene (z3), or contains polypropylene (z3) and a propylene-based polymer (P3) other than polypropylene (z3). That is, the outer layer contains a propylene-based polymer (P3) and further contains one or both of an ethylene-based polymer (e3) and a polypropylene (z3) as the propylene-based polymer (P3). When the outer layer contains the polypropylene (z3), it is particularly preferable that the outer layer also contains the propylene-based polymer (P3) other than the polypropylene (z3).

[0152] In terms of making it easier to adjust the elongational viscosity of the laminated film to a desired value, the propylene-based polymer (P3) (e.g., polypropylene (z3) and a propylene-based polymer (P3) other than polypropylene (z3)) is preferably either one or both of a propylene-ethylene block copolymer (bPP) and a homopolypropylene (hPP).

[0153] In terms of particularly improving the effect of suppressing drawdown during heat molding of the laminate film and particularly improving the formability of the laminate film during heat molding, when the outer layer contains a propylene-based polymer (P3) and an ethylene-based polymer (e3), the melt flow rates of the propylene-based polymer (P3) and the ethylene-based polymer (e3) are preferably both in any of the above-mentioned numerical ranges. For example, the melt flow rates of the propylene-based polymer (P3) and the ethylene-based polymer (e3) are preferably 3 g / 10 min or less.

[0154] From the viewpoint of making it easier to adjust the extensional viscosity of the laminated film to a target value, it is preferable that the outer layer contains, as the propylene-based polymer (P3), either one or both of a propylene-ethylene block copolymer and a homopolypropylene, and further contains either one or both of an ethylene-based polymer (e3) and a polypropylene (z3) as the propylene-based polymer (P3), the ethylene-based polymer (e3) being one or more selected from the group consisting of low-density polyethylene, linear low-density polyethylene, and metallocene-catalyzed linear low-density polyethylene, the polypropylene (z3) being homopolypropylene, and when the outer layer contains polypropylene (z3) (i.e., homopolypropylene), it also contains a propylene-based polymer (P3) other than polypropylene (z3).

[0155] The outer layer containing a polyolefin-based resin may contain only a polyolefin-based resin (i.e., it may consist of a polyolefin-based resin), or it may contain a polyolefin-based resin and other components (sometimes referred to in this specification as “other component (3)”) other than the polyolefin-based resin (i.e., it may consist of a polyolefin-based resin and the other components).

[0156] The other component (3) contained in the outer layer is not particularly limited and can be selected arbitrarily depending on the purpose. For example, it may be either a resin component or a non-resin component, and examples thereof include the same as the other component (1) contained in the functional layer.

[0157] The outer layer may contain only one type of other component (3) or two or more types. When there are two or more types, the combination and ratio thereof can be arbitrarily selected depending on the purpose.

[0158] In an outer layer containing a polyolefin resin, the ratio of the polyolefin resin content (parts by mass) to the total mass (parts by mass) of the outer layer ([polyolefin resin content (parts by mass) of outer layer)] / [total mass (parts by mass) of outer layer]×100) is preferably 80% by mass or more, more preferably 90% by mass or more, and may be, for example, any one of 95% by mass or more, 97% by mass or more, and 99% by mass or more. When the ratio is equal to or more than the lower limit, the rigidity, heat resistance, appearance, and protective effect of the laminate film are further improved, and the effect of suppressing drawdown during heat molding of the laminate film is further increased, thereby improving the formability of the laminate film during heat molding. On the other hand, the proportion is 100% by mass or less. The above ratio is usually the same as the ratio of the polyolefin resin content to the total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming an outer layer described below ([content (parts by mass) of polyolefin resin in the composition for forming an outer layer)] / [total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming an outer layer)]×100).

[0159] When the outer layer contains a propylene-based polymer (P3) and an ethylene-based polymer (e3), or contains two or more kinds of propylene-based polymers (P3), the ratio of the total content (parts by mass) of the propylene-based polymer (P3) and the ethylene-based polymer (e3) to the total mass (parts by mass) of the outer layer (([content (parts by mass) of the propylene-based polymer (P3) in the outer layer)] + [content (parts by mass) of the ethylene-based polymer (e3) in the outer layer)]) / [total mass (parts by mass) of the outer layer] × 100) is preferably 80% by mass or more, more preferably 90% by mass or more, and may be, for example, any one of 95% by mass or more, 97% by mass or more, and 99% by mass or more. When the ratio is equal to or more than the lower limit, the rigidity, heat resistance, appearance, and protective effect of the laminate film are further improved, and the effect of suppressing drawdown during heat molding of the laminate film is further improved, and the moldability of the laminate film during heat molding is further improved. On the other hand, the proportion is 100% by mass or less. The ratio is usually the same as the ratio of the total content (parts by mass) of the propylene-based polymer (P3) and the ethylene-based polymer (e3) to the total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming an outer layer described later (([content (parts by mass) of the propylene-based polymer (P3) in the composition for forming an outer layer)] + [content (parts by mass) of the ethylene-based polymer (e3) in the composition for forming an outer layer)]) / [total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming an outer layer)] × 100). When the outer layer or the composition for forming an outer layer does not contain the ethylene polymer (e3), the content of the ethylene polymer (e3) in the outer layer or the composition for forming an outer layer is 0 part by mass.

[0160] When the outer layer contains either one or both of polypropylene (z3) and ethylene-based polymer (e3), the ratio of the total content of polypropylene (z3) and ethylene-based polymer (e3) to the total mass of the outer layer (([content of polypropylene (z3) in the outer layer (parts by mass)] + [content of ethylene-based polymer (e3) in the outer layer (parts by mass)]) / [total mass of the outer layer (parts by mass)] × 100) is preferably 5 mass% or more, and may be, for example, 10 mass% or more or 15 mass% or more. When the ratio is equal to or more than the lower limit, the rigidity, heat resistance, appearance, and protective effect of the laminate film are further improved, and the effect of suppressing drawdown during heat molding of the laminate film is further improved, and the moldability of the laminate film during heat molding is further improved. On the other hand, the upper limit of the ratio is not particularly limited. For example, the ratio is preferably 25% by mass or less, in order to further suppress the excessive use of polypropylene (z3) or ethylene polymer (e3). The ratio is usually the same as the ratio of the total content (parts by mass) of polypropylene (z3) and ethylene-based polymer (e3) to the total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming an outer layer described later (([content (parts by mass) of polypropylene (z3) in the composition for forming an outer layer)] + [content (parts by mass) of ethylene-based polymer (e3) in the composition for forming an outer layer)]) / [total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming an outer layer)] × 100). Here, when the outer layer or the composition for forming an outer layer does not contain polypropylene (z3), the content of polypropylene (z3) in the outer layer or the composition for forming an outer layer is 0 parts by mass. When the outer layer or the composition for forming an outer layer does not contain an ethylene-based polymer (e3), the content of the ethylene-based polymer (e3) in the outer layer or the composition for forming an outer layer is 0 parts by mass.

[0161] As explained above, when the extensional viscosity of the polypropylene (z3) is 10000 Pa s or more and the extensional viscosity of the ethylene polymer (e3) is 10000 Pa s or more, it is particularly preferable that the ratio of the total content of the polypropylene (z3) and the ethylene polymer (e3) to the total mass of the outer layer is in any of the above-mentioned numerical ranges. In such a case, in addition to further improving the rigidity, heat resistance, appearance, and protective effect of the laminate film, the effect of suppressing drawdown during heat molding of the laminate film becomes particularly high, and the moldability of the laminate film during heat molding becomes particularly high.

[0162] The content of the other component (3) in the outer layer can be appropriately adjusted depending on the type of the other component (3). For example, in the outer layer, the ratio of the content of the other component (3) to the total mass of the outer layer ([content of the other component (3) in the outer layer (parts by mass)] / [total mass of the outer layer (parts by mass)]×100) is preferably 0.1 to 20% by mass, more preferably 0.1 to 10% by mass, and may be, for example, any one of 0.1 to 5% by mass, 0.1 to 3% by mass, and 0.1 to 1% by mass. When the ratio is equal to or more than the lower limit, the effect obtained by using the other component (3) is enhanced. When the ratio is equal to or less than the upper limit, excessive use of the other component (3) is further suppressed.

[0163] The outer layer may be one layer (single layer) or two or more layers. When the outer layer is made of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited as long as it does not impair the effects of the present invention.

[0164] From the viewpoint of simplifying the structure of the laminated film, it is preferable that the outer layer consists of a single layer.

[0165] The thickness of the outer layer is preferably 50 to 400 μm, more preferably 60 to 300 μm, and even more preferably 70 to 200 μm. When the thickness of the outer layer is equal to or greater than the lower limit, the rigidity, heat resistance, appearance, and protective effect of the laminated film are improved, and the effect of suppressing drawdown during heat molding of the laminated film is enhanced, thereby improving the moldability of the laminated film during heat molding. When the thickness of the outer layer is equal to or less than the upper limit, the thickness of the outer layer is further prevented from becoming excessive. Here, the "thickness of the outer layer" means the thickness of the entire outer layer. For example, the thickness of an outer layer consisting of multiple layers means the total thickness of all layers that make up the outer layer.

[0166] The ratio of the thickness of the outer layer to the thickness of the laminated film is preferably 5 to 40%, more preferably 5 to 30%, and even more preferably 5 to 35%. When the ratio is equal to or greater than the lower limit, the rigidity, heat resistance, appearance, and protective effect of the laminated film are improved, and the effect of suppressing drawdown during heat molding of the laminated film is increased, thereby improving the moldability of the laminated film during heat molding. When the ratio is equal to or less than the upper limit, the thickness of the outer layer is further prevented from becoming excessive.

[0167] <Adhesive layer> The laminated film of the present embodiment may include an adhesive layer (for example, adhesive layer 15 shown in Figures 2 and 3) that does not fall into any of the functional layer, oxygen barrier layer, inner layer, and outer layer. The adhesive layer is a layer for adhering two adjacent layers in the laminated film, and contains a component that exhibits adhesiveness. The adhesive layer is an optional component, and the laminated film does not necessarily have to have an adhesive layer, but the laminated film has a more stable structure when it has an adhesive layer.

[0168] The position of the adhesive layer in the laminated film is not particularly limited as long as it is not the outermost layer of the laminated film. The adhesive layer may be disposed at one location in the laminated film, or at two or more locations. When the adhesive layer is disposed at two or more locations in the laminated film, these adhesive layers at two or more locations may be the same as or different from each other. Here, the embodiment in which "the adhesive layers at two or more locations may be the same as or different from each other" is the same as the embodiment in which "the functional layers at two or more locations may be the same as or different from each other" described above. Furthermore, "the adhesive layers are different from each other" means that "at least one of the constituent materials and thicknesses of the adhesive layers are different from each other".

[0169] The laminated film may have, for example, an adhesive layer between the oxygen barrier layer and the functional layer. That is, in the laminated film, the oxygen barrier layer, the adhesive layer, and the functional layer may be laminated in this order in the thickness direction. The structure of the laminated film having such a configuration is more stable. For example, when a laminated film has a pair of functional layers and an oxygen barrier layer provided between the pair of functional layers in the thickness direction, an adhesive layer may be provided between the pair of functional layers and the oxygen barrier layer. That is, in a laminated film (for example, laminated film 1 shown in FIG. 2, laminated film 2 shown in FIG. 3), a functional layer (for example, first functional layer 111 shown in FIG. 2-FIG. 3), an adhesive layer (for example, first adhesive layer 151 shown in FIG. 2-FIG. 3), an oxygen barrier layer (for example, oxygen barrier layer 12 shown in FIG. 2-FIG. 3), an adhesive layer (for example, second adhesive layer 152 shown in FIG. 2-FIG. 3), and a functional layer (for example, second functional layer 112 shown in FIG. 2-FIG. 3) may be laminated in this order in the thickness direction.

[0170] The adhesive layer preferably has transparency.

[0171] The adhesive layer is preferably a resin layer containing an adhesive resin as a component that exhibits the above-mentioned adhesiveness.

[0172] The adhesive resin may be, for example, a polyolefin resin. The polyolefin resin is a resin having structural units derived from an olefin, and may be, for example, a modified polyolefin such as an acid-modified polyolefin having an acidic group. Examples of polyolefin resins include ethylene copolymers, propylene copolymers, butene copolymers, modified products of these copolymers (in other words, modified copolymers), acid-modified polyethylene, acid-modified polypropylene, and the like. The polyolefin resin may be a random copolymer, a graft copolymer or a block copolymer, in terms of further improving adhesiveness.

[0173] Examples of the ethylene-based copolymer contained in the adhesive layer include the ethylene-based copolymers described above as being contained in the functional layer, modified products thereof (modified copolymers), and the like. The propylene-based copolymer contained in the adhesive layer may be, for example, a copolymer of propylene and a vinyl group-containing monomer, a modified product thereof (modified copolymer), etc., and may also be, for example, the propylene-based copolymer described above as the one contained in the functional layer. More specifically, such a propylene-based copolymer may be, for example, a straight-chain low-density polypropylene grafted with maleic anhydride, a propylene-based thermoplastic elastomer, etc. Examples of the butene copolymer contained in the adhesive layer include copolymers of 1-butene and vinyl group-containing monomers, copolymers of 2-butene and vinyl group-containing monomers, and modified products of these copolymers (modified copolymers).

[0174] The adhesive layer may contain only one type of component that exhibits adhesiveness (e.g., the adhesive resin), or two or more types. If there are two or more types, the combination and ratio of these can be selected arbitrarily depending on the purpose.

[0175] The adhesive layer may contain, in addition to the component that exhibits adhesiveness (e.g., the adhesive resin), other components (sometimes referred to in this specification as “other components (5)”), provided that the adhesive layer’s adhesiveness is not impaired. Examples of the other components (5) contained in the adhesive layer include antioxidants.

[0176] The adhesive layer may contain only one type of other component (5) or two or more types. When there are two or more types, the combination and ratio thereof can be arbitrarily selected depending on the purpose.

[0177] In the adhesive layer, the ratio of the content of the component that exhibits adhesiveness to the total mass of the adhesive layer ([content of the component that exhibits adhesiveness in the adhesive layer (parts by mass)] / [total mass of the adhesive layer (parts by mass)]×100) is preferably 80% by mass or more, and more preferably 90% by mass or more. When this ratio is equal to or greater than the lower limit, the adhesiveness of the adhesive layer becomes higher. On the other hand, the proportion is 100% by mass or less. The above ratio is usually the same as the ratio of the content (parts by mass) of components that exhibit adhesive properties to the total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming an adhesive layer described below ([content (parts by mass) of components that exhibit adhesive properties in the composition for forming an adhesive layer)] / [total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming an adhesive layer)]×100).

[0178] The adhesive layer may be one layer (single layer) or two or more layers. When the adhesive layer is made of multiple layers, these layers may be the same or different from each other, and the combination of these layers is not particularly limited as long as it does not impair the effects of the present invention.

[0179] The thickness of the adhesive layer is not particularly limited, but is preferably 3 to 50 μm, more preferably 5 to 40 μm, and even more preferably 7 to 30 μm. When the thickness of the adhesive layer is equal to or greater than the lower limit, the adhesiveness of the adhesive layer is increased. When the thickness of the adhesive layer is equal to or less than the upper limit, the adhesive layer is prevented from becoming excessively thick. In addition, when the laminated film has transparency, the thinner the adhesive layer, the more the transparency of the package (for example, the base material described below) is improved, making it easier to visually check the contents from the outside of the laminated film side (for example, the base material side) of the package. Here, "thickness of adhesive layer" means the thickness of the entire adhesive layer; for example, the thickness of an adhesive layer consisting of multiple layers means the total thickness of all layers that make up the adhesive layer.

[0180] The ratio of the thickness of the adhesive layer to the thickness of the laminated film is preferably 1 to 10%, more preferably 1 to 8%, and even more preferably 1 to 6%. When the ratio is equal to or greater than the lower limit, the adhesiveness of the adhesive layer is increased. When the ratio is equal to or less than the upper limit, the adhesive layer is prevented from becoming excessively thick. In addition, when the laminated film has transparency, the smaller the ratio, the more the transparency of the package (e.g., the base material described below) is improved, making it easier to visually check the contents from the outside of the laminated film side (e.g., the base material side) of the package.

[0181] <Other layers> The laminate film of this embodiment may or may not have other layers that do not fall into the category of a functional layer, an oxygen barrier layer, an inner layer, an outer layer, or an adhesive layer, as long as the effects of the present invention are not impaired.

[0182] The type and number of the other layers are not particularly limited and can be arbitrarily selected depending on the purpose. An example of the other layer is a layer that does not contain a polyolefin resin. When the laminate film does not have such other layers, the recyclability of the laminate film is improved.

[0183] <Example of a laminated film having an inner layer and an outer layer> When the laminate film of this embodiment has the inner layer and outer layer, the ratio of the total thickness of the functional layer, the inner layer and the outer layer to the thickness of the laminate film (([thickness of functional layer] + [thickness of inner layer] + [thickness of outer layer]) / [thickness of laminate film] × 100) is preferably 85% or more, more preferably 86 to 99%, and even more preferably 87 to 98%. In a laminate film having such a ratio, the effect of suppressing drawdown during heat molding is higher, the formability during heat molding is higher, and the effects obtained by having the inner layer and outer layer are greater.

[0184] In terms of enhancing the above-mentioned effects, in a laminate film having an inner layer and an outer layer, the inner layer contains a propylene-based polymer (P2), the outer layer contains a propylene-based polymer (P3), and an elongation rate of 50 to 70 s calculated by the Cogswell method from measurement data of the laminate film at a temperature of 240° C. using a twin capillary rheometer is -1 It is preferable that the elongational viscosity of the laminated film at is 9,300 Pa·s or more, and the ratio of the total thickness of the functional layer, the inner layer and the outer layer to the thickness of the laminated film is 85% or more.

[0185] In terms of enhancing the above-mentioned effects, in a laminate film having an inner layer and an outer layer, the functional layer contains a propylene-based polymer (P1), and an elongation rate of 60 to 100 s calculated by the Cogswell method from measurement data of the functional layer at a temperature of 240° C. using a twin capillary rheometer is -1 The elongation viscosity of the functional layer at elongation speed is 10,000 Pa·s or more, and the elongation speed is 50 to 70 s -1The functional layer may have an elongational viscosity of 10,000 Pa s or more at an elongation rate of 50 to 70 s calculated by a Cogswell method from measurement data at a temperature of 240° C. of the laminated film using a twin capillary rheometer, the inner layer may contain a propylene-based polymer (P2), the outer layer may contain a propylene-based polymer (P3), and -1 It is more preferable that the elongational viscosity of the laminated film at is 9,300 Pa·s or more, and the ratio of the total thickness of the functional layer, the inner layer and the outer layer to the thickness of the laminated film is 85% or more. In a laminated film having an inner layer and an outer layer, the inner layer contains a propylene-based polymer (P2) and further contains either one or both of an ethylene-based polymer (e2) and a polypropylene (z2) as the propylene-based polymer (P2), and when the inner layer contains the polypropylene (z2), the inner layer also contains the propylene-based polymer (P2) other than the polypropylene (z2), the outer layer contains a propylene-based polymer (P3) and further contains either one or both of an ethylene-based polymer (e3) and a polypropylene (z3) as the propylene-based polymer (P3), and when the outer layer contains the polypropylene (z3), the outer layer also contains the propylene-based polymer (P3) other than the polypropylene (z3), and an elongation rate of 50 to 70 s calculated by the Cogswell method from measurement data of the laminated film at a temperature of 240° C. using a twin capillary rheometer. -1 It is more preferable that the elongational viscosity of the laminated film at is 9,300 Pa·s or more, and the ratio of the total thickness of the functional layer, the inner layer and the outer layer to the thickness of the laminated film is 85% or more.

[0186] In terms of enhancing the above-mentioned effects, in a laminate film having an inner layer and an outer layer, the functional layer contains a propylene-based polymer (P1), and an elongation rate of 60 to 100 s calculated by the Cogswell method from measurement data of the functional layer at a temperature of 240° C. using a twin capillary rheometer is -1 The elongation viscosity of the functional layer at elongation speed is 10,000 Pa·s or more, and the elongation speed is 50 to 70 s-1 the inner layer contains a propylene-based polymer (P2) and further contains either one or both of an ethylene-based polymer (e2) and a polypropylene (z2) as the propylene-based polymer (P2), and when the inner layer contains the polypropylene (z2), the inner layer also contains the propylene-based polymer (P2) other than the polypropylene (z2); the outer layer contains a propylene-based polymer (P3) and further contains either one or both of an ethylene-based polymer (e3) and a polypropylene (z3) as the propylene-based polymer (P3), and when the outer layer contains the polypropylene (z3), the outer layer also contains the propylene-based polymer (P3) other than the polypropylene (z3); and an elongational viscosity of the functional layer at 240° C. calculated by the Cogswell method using a twin capillary rheometer from measurement data of the laminated film at a temperature of 240° C. is 50 to 70 s -1 It is particularly preferable that the elongational viscosity of the laminated film at is 9,300 Pa·s or more, and that the ratio of the total thickness of the functional layer, the inner layer and the outer layer to the thickness of the laminated film is 85% or more.

[0187] In the laminate film of this embodiment, the ratio of the polyolefin resin content to the total mass of the laminate film ([polyolefin resin content in laminate film (parts by mass)] / [total mass of laminate film (parts by mass)]×100) is preferably 80% by mass or more, more preferably 85 to 100% by mass, and even more preferably 90 to 98% by mass. When the ratio is equal to or more than the lower limit, the recyclability of the laminate film becomes higher. When the ratio is equal to or less than the upper limit, other properties can be more easily imparted to the laminate film.

[0188] The total thickness of the laminate film is not particularly limited, but is preferably 300 to 1500 μm, more preferably 315 to 1400 μm, and even more preferably 330 to 1300 μm. When the total thickness of the laminate film is equal to or greater than the lower limit, the strength of the laminate film is increased. When the total thickness of the laminate film is equal to or less than the upper limit, the laminate film is prevented from becoming excessively thick.

[0189] In the laminated film, all layers constituting the film (e.g., the functional layer, the oxygen barrier layer, the inner layer, the outer layer, the adhesive layer, and the other layers) are preferably unstretched layers (films). Such unstretched laminated films are particularly excellent in formability and are particularly suitable for forming packaging bodies, for example. The type of packaging material to be constructed using the laminated film can be arbitrarily selected depending on the purpose.

[0190] <<Laminated film (other embodiments)>> A laminated film having a functional layer and an oxygen barrier layer, the elongation rate being 60 to 100 s 2 calculated by the Cogswell method from the measurement data of the laminated film at a temperature of 240° C. when a twin capillary rheometer is used. -1 A laminate film having an elongational viscosity of 9800 Pa·s or more at 100° C. (In this specification, this laminate film may be referred to as "laminate film (2)". In that case, the laminate film described above may be referred to as "laminate film (1)".) exhibits the same effects as the laminate film (laminate film (1)) according to one embodiment of the present invention described above. That is, the laminate film (laminate film (2)) according to this embodiment exhibits such an elongational viscosity, and thus suppresses so-called drawdown, in which the heated portion of the laminate film sags when the laminate film is heat-molded to produce a package using the laminate film. Therefore, the molded product obtained by heat-molding the laminate film has the shape and size as designed, and the laminate film has excellent moldability during heat molding. Furthermore, the laminate film of this embodiment (laminate film (2)) can have polyolefin as the main constituent material of its multiple resin layers. In particular, by using polypropylene, which has high fluidity at high temperatures, the laminate film can have excellent moldability during hot molding and excellent recyclability.

[0191] The elongation viscosity of the laminated film (2) is 9800 Pa·s or more, and the elongation rate is 60 to 100 s, calculated by the Cogswell method from the measurement data of the laminated film (2) at a temperature of 240°C. -1 The minimum elongation viscosity of the laminated film (2) at 60 to 100 s is 9800 Pa·s or more. -1 In the entire elongation speed range, the elongation viscosity of the laminated film (2) is 9800 Pa·s or more.

[0192] As described above, the laminated film (2) is stretched at a stretching speed of 60 to 100 s -1 It is similar to laminated film (1), except that the elongational viscosity at 200° C. is specified to be 9,800 Pa·s or more. The laminate film (2) can be suitably constructed, for example, by making the functional layer contain a large amount of low-density polyethylene (LDPE) as the ethylene polymer (e1) or a large amount of metallocene-catalyzed high melt strength polypropylene (HMSPP) as the polypropylene (z1).

[0193] The laminated film (1) has an elongation speed of 50 to 70 s -1 The elongational viscosity at elongation is 9300 Pa·s or more, and the elongational speed is 60 to 100 s -1 The extensional viscosity at 200° C. is preferably 8,800 Pa·s or more, and more preferably 9,800 Pa·s or more.

[0194] Regardless of whether or not it corresponds to laminated film (1), elongation speed is 60 to 100 s -1 In the case of a laminated film having an elongational viscosity of 9300 Pa·s or more at an elongation speed of 60 to 100 s -1The elongational viscosity at is preferably 9900 Pa s or more, and more preferably 10000 Pa s or more. The higher the elongational viscosity of the laminate film, the higher the effect of suppressing drawdown during heat molding of the laminate film, and the higher the formability of the laminate film during heat molding tends to be.

[0195] The laminated film is stretched at a rate of 60 to 100 s -1 The upper limit of the elongational viscosity at elongation speed of 60 to 100 s is not particularly limited. -1 The elongation viscosity (maximum value of elongation viscosity) at an elongation rate of 60 to 100 s calculated by the Cogswell method from the measurement data at a temperature of 240° C. of the laminated film is preferably 20,000 Pa·s or less. -1 The maximum elongational viscosity of the laminated film at 20000 Pa·s or less is preferably 60 to 100 s. -1 In the entire elongation speed range, the elongation viscosity of the laminated film is preferably 20,000 Pa·s or less.

[0196] <<Laminated film manufacturing method>> The laminated film can be produced, for example, by a feed block method in which resins or resin compositions that are materials for forming each layer are melt-extruded using several extruders, a co-extrusion T-die method such as a multi-manifold method, or an air-cooled or water-cooled co-extrusion inflation method.

[0197] When the resin composition is used, for example, a mixture of two or more components (dry blend, non-kneaded material) may be directly fed into the extruder as the resin composition, or a pre-kneaded material in which two or more components are kneaded in advance may be fed into the extruder as the resin composition. The pre-kneaded product can be obtained, for example, by melt-kneading two or more components using an apparatus such as a twin-screw extruder or a Banbury mixer.

[0198] The laminated film can also be produced by first separately preparing two or more films to constitute any two or more of these layers, and then laminating them together using a thermal lamination method or the like without using an adhesive, and then, if necessary, further laminating other layers so as to achieve the desired arrangement.

[0199] The resin composition which is the material for forming any layer in the laminated film may be produced by adjusting the type and content of the components so that the layer to be formed contains the desired components in the desired content. For example, the content ratio of the components which do not vaporize at room temperature in the resin composition is usually the same as the content ratio of the components in the layer formed from this resin composition.

[0200] Examples of resin compositions (sometimes referred to in this specification as "compositions for forming functional layers") for forming functional layers (for example, in the laminate film 1 shown in Figure 2 or the laminate film 2 shown in Figure 3, functional layer 11, more specifically, first functional layer 111 and second functional layer 112) include resin compositions containing the polyolefin resin and, if necessary, other components (1).

[0201] Examples of resin compositions (sometimes referred to herein as "oxygen barrier layer-forming compositions") for forming an oxygen barrier layer (for example, oxygen barrier layer 12 in laminate film 1 shown in FIG. 2 or laminate film 2 shown in FIG. 3) include resin compositions containing an oxygen barrier resin and, if necessary, the other component (4).

[0202] Examples of the resin composition (sometimes referred to as an "inner layer forming composition" in this specification) for forming an inner layer (e.g., inner layer 13 in the laminate film 2 shown in FIG. 3) include a resin composition containing the polyolefin resin and, if necessary, other components (2).

[0203] Examples of the resin composition (sometimes referred to in this specification as an "outer layer forming composition") for forming an outer layer (e.g., outer layer 14 in the laminate film 2 shown in FIG. 3) include a resin composition containing the polyolefin resin and, if necessary, other components (3).

[0204] Examples of resin compositions (sometimes referred to in this specification as "adhesive layer-forming compositions") for forming adhesive layers (for example, in the laminate film 1 shown in FIG. 2 or the laminate film 2 shown in FIG. 3, adhesive layer 15, more specifically, first adhesive layer 151 and second adhesive layer 152) include resin compositions containing a component that exhibits the above-mentioned adhesiveness and, if necessary, other components (5) other than those mentioned above.

[0205] <<Packaging>> A packaging body according to one embodiment of the present invention is constructed using the laminate film according to one embodiment of the present invention described above. The packaging body of the present embodiment may be a known packaging body, except for the use of the laminated film.

[0206] A preferred package of this embodiment is, for example, a package that has a lid material and a base material, and is constructed by sealing the lid material and the base material, and one or both of the lid material and the base material are constructed using the laminate film. The base material may be, for example, a molded product of a resin film having a recess for forming a storage section in a package. The resin film may be the laminate film or a resin film other than the laminate film. Since the laminated film has excellent formability during heat molding, it is preferable that the base material is a molded product of the laminated film. That is, a more preferable package of this embodiment includes a package that includes a lid material and a base material, is configured by sealing the lid material and the base material, and the base material is a molded product of the laminated film. In such a more preferable package, the lid material may be the laminated film, or may be a film other than the laminated film (for example, a resin film).

[0207] FIG. 4 is a cross-sectional view that illustrates an example of the packaging body of the present embodiment. The packaging body 101 shown in Fig. 4 is configured to include a lid material 8 and a base material 10. The base material 10 is configured using the laminate film 1 shown in Fig. 2 or the laminate film 2 shown in Fig. 3, and more specifically, is a molded body (heat-molded body) of the laminate film 1 or the laminate film 2. In the base material 10 in FIG. 4, the distinction between the layers in the laminate film 1 or 2 constituting the base material 10 is omitted.

[0208] The base material 10 has a recess 100 formed therein. One surface (sometimes referred to as the "second surface" in this specification) 10b of the base material 10 in the area excluding the recess 100 and one surface (sometimes referred to as the "second surface" in this specification) 8b of the cover material 8 are both sealing surfaces and face each other. The package 101 is formed by sealing the lid material 8 and the base material 10. More specifically, the second surface 10b of the base material 10 except for the recess 100 and the second surface 8b of the lid material 8 are overlapped and sealed to each other in the area near their peripheral edges. As a result, in the area of ​​the recess 100 of the base material 10, a storage section 101a is formed between the second surface 10b of the base material 10 and the second surface 8b of the lid material 8. The item 9 is stored in this storage section 101a.

[0209] When the base material 10 is constructed using the laminated film 1 shown in Fig. 2, one surface (second surface) 10b of the base material 10 is preferably the same as the second surface 111b of the first functional layer 11 in the laminated film 1. The other surface (sometimes referred to as the "first surface" in this specification) 10a of the base material 10 is preferably the same as the first surface 112a of the second functional layer 11 in the laminated film 1. When the base material 10 is constructed using the laminated film 2 shown in Fig. 3, one surface (second surface) 10b of the base material 10 is preferably the same as the second surface 13b of the inner layer 13 in the laminated film 2. The other surface (first surface) 10a of the base material 10 is preferably the same as the first surface 14a of the outer layer 14 in the laminated film 2.

[0210] Examples of the lid material 8 include lid materials having an aluminum layer; lid materials (resin films) having a layer containing a polyolefin such as polyethylene or polypropylene, and the like. The lid material 8 may be the laminate film, for example, the laminate film 1 shown in FIG. 2 or the laminate film 2 shown in FIG. 2, one surface (second surface) 8b of the lid material 8 is preferably the same as the second surface 111b of the first functional layer 11 in the laminate film 1. The other surface (sometimes referred to as the "first surface" in this specification) 8a of the lid material 8 is preferably the same as the first surface 112a of the second functional layer 11 in the laminate film 1. 3, one surface (second surface) 8b of the lid material 8 is preferably the same as the second surface 13b of the inner layer 13 in the laminate film 2. The other surface (first surface) 8a of the lid material 8 is preferably the same as the first surface 14a of the outer layer 14 in the laminate film 2.

[0211] In Figure 4, some gaps can be seen between the stored item 9 and the base material 10, and between the stored item 9 and the lid material 8 within the storage section 101a of the packaging body 101. However, the presence of these gaps is not essential for the packaging body 101 in which the stored item 9 is stored.

[0212] The thickness of the base material 10 at its flat portion may be the same as the thickness of the laminate film 1 or the laminate film 2 described above.

[0213] <<Manufacturing method of packaging body>> The packaging body can be produced, for example, by forming a storage section for storing the packaged item (in other words, the contents) using the laminated films together, or the laminated film and a film other than the laminated film, while storing the packaged item, and then heat-sealing the areas of these films other than the storage section. The packaging body of this embodiment can be produced in the same manner as known packaging bodies, except that the laminated film is used.

[0214] In producing a package, for example, when using a laminate film having the configuration shown in Fig. 2, it is preferable to package the object by arranging the first functional layer in the laminate film facing the object to be packaged and arranging the second functional layer facing the opposite side to the object to be packaged. When using the laminate film shown in Fig. 3, it is preferable to package the object by arranging the inner layer in the laminate film facing the object to be packaged and arranging the outer layer facing the opposite side to the object to be packaged.

[0215] The heating temperature during heat sealing is preferably 160 to 200°C.

[0216] When the base material is produced by thermoforming the laminated film, the thermoforming can be performed by a known method. For example, the heating temperature during thermoforming is preferably 145 to 500°C. EXAMPLES

[0217] The present invention will be described in more detail below with reference to specific examples, although the present invention is not limited to the following examples.

[0218] The raw materials used in each of the examples and comparative examples are as follows. bPP: Propylene-ethylene block copolymer (Sumitomo Chemical Co., Ltd. "Sumitomo Noblen (registered trademark) AH1311", MFR 0.5 g / 10 min, density 0.9 g / cm 3 ) hPP: homopolypropylene (Japan Polypropylene Corporation, "Novatec (registered trademark) PP EA9", MFR 0.5 g / 10 min, density 0.9 g / cm 3 ) LDPE: Low-density polyethylene (Sumitomo Chemical Co., Ltd. "Sumikathene (registered trademark) L211", MFR 2.0 g / 10 min, density 0.924 g / cm 3 ) HMSPP: Metallocene-catalyzed high melt strength polypropylene (Japan Polypropylene Corporation's "Waymax (registered trademark) MFX6", MFR 2.8 g / 10 min, density 0.9 g / cm 3 ) EVOH: Ethylene-vinyl alcohol copolymer ("EVAL (registered trademark) F101A" manufactured by Kuraray Co., Ltd., copolymerization ratio of ethylene 32 mol%, melting point 183°C) Modified PP: Acid-modified polypropylene (adhesive resin, "Admer (registered trademark) QF551" manufactured by Mitsui Chemicals, Inc.) PG: Pigment (cream pigment masterbatch, Dainichi Seika Chemicals "PP-M-SSCD 16N9913 Cream")

[0219] The HMSPP was used in the form of granules with a particle size of about 5 mm. Measurement data was obtained at a temperature of 240°C using a twin capillary rheometer "RHEOGRAPH 20." The elongation rate of 60 to 100 s was calculated from the measurement data by the Cogswell method using the method described above. -1 The extensional viscosity of HMSPP at this temperature was 10,000 to 20,000 Pa·s. The LDPE was also subjected to the same method as for the HMSPP, with a temperature of 240°C and an elongation rate of 60 to 100 s -1 The extensional viscosity at 10000 to 20000 Pa·s was measured.

[0220] [Example 1] <<Laminated film manufacturing>> A laminated film having the structure shown in FIG. 3 was produced by the following procedure. That is, the bPP (73 parts by mass), the LDPE (18 parts by mass), and the PG (9 parts by mass) were mixed at room temperature to prepare a resin composition (1).

[0221] By co-extruding the bPP, the resin composition (1), the modified PP, the EVOH, the modified PP, the resin composition (1), and the bPP in this order, a laminated film (thickness 800 μm) was obtained, which was composed of an inner layer (thickness 180 μm), a first functional layer (thickness 184 μm), a first adhesive layer (thickness 20 μm), an oxygen barrier layer (thickness 32 μm), a second adhesive layer (thickness 20 μm), a second functional layer (thickness 184 μm), and an outer layer (thickness 180 μm) laminated in this order in the thickness direction. The inner layer, the first functional layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, the second functional layer, and the outer layer are all unstretched layers.

[0222] The ratio of the total content of LDPE and HMSPP to the total mass of the functional layers (first functional layer, second functional layer) in the laminated film obtained above is shown in the column ``Percentage of total content of LDPE and HMSPP (mass %)'' for the first functional layer and second functional layer in Table 1. Similarly, in the following examples and comparative examples, the percentages (mass %) of the total content of LDPE and HMSPP are shown in Tables 1 to 3.

[0223] The percentage of the polyolefin resin content in the laminate film obtained above relative to the total mass of the laminate film is shown in Table 1 in the column "Polyolefin resin content (mass %)". Similarly, in the following examples and comparative examples, the content ratios (mass %) of the polyolefin resin are shown in Tables 1 to 3.

[0224] <<Evaluation of laminated film>> <Measurement of extensional viscosity of laminated film> The laminated film obtained above was cut into a rectangular or nearly rectangular shape with a size of about 5 mm x about 5 mm to prepare a measurement sample. This measurement sample was stretched at a temperature of 240 ° C. and an elongation rate of 50 to 70 s in the same manner as in the case of the HMSPP. -1 and extension speed 60-100s -1 The elongational viscosity at each temperature was measured, and these measured values ​​were used as the elongational viscosity of the laminated film. The results are shown in Table 1.

[0225] <Measurement of elongational viscosity of functional layer> Granules of resin composition (1) with a particle size of about 5 mm were prepared, and these granules were subjected to elongation at a temperature of 240°C and an elongation rate of 50 to 70 s in the same manner as in the case of the HMSPP described above. -1 and extension speed 60-100s -1 The extensional viscosities at these temperatures were measured, and these measured values ​​were used as the extensional viscosities of the functional layers (first functional layer and second functional layer). The results are shown in Table 1.

[0226] <Measurement of drawdown length of laminated film> A test piece measuring 300 mm in length and 160 mm in width was cut out from the laminated film obtained above, and a heater was placed on top of the test piece at a distance of 100 mm from the heater. Next, the heater temperature was set to 500° C., and the test piece was heated at 400° C. for 120 seconds, and the drawdown length of the test piece was measured by the method described above. The results are shown in Table 1.

[0227] <Measurement of tensile impact strength of laminated film> The laminated film obtained above was measured for tensile impact strength in the resin flow direction (MD) and the direction perpendicular to the resin flow direction (TD) in accordance with JIS K 7160A. The results are shown in Table 1.

[0228] <<Laminated film manufacturing and evaluation>> [Example 2] The bPP (80 parts by mass) and the LDPE (20 parts by mass) were mixed at room temperature to prepare a resin composition (2).

[0229] Except for using the resin composition (2) instead of the bPP as the resin constituting the inner layer and outer layer, the same method as in Example 1 was used to obtain a laminated film (thickness 800 μm) composed of an inner layer (thickness 180 μm), a first functional layer (thickness 184 μm), a first adhesive layer (thickness 20 μm), an oxygen barrier layer (thickness 32 μm), a second adhesive layer (thickness 20 μm), a second functional layer (thickness 184 μm), and an outer layer (thickness 180 μm) stacked in the thickness direction in this order. The inner layer, the first functional layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, the second functional layer, and the outer layer are all unstretched layers.

[0230] The obtained laminated film was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0231] [Example 3] The bPP (76 parts by mass), the LDPE (19 parts by mass), and the PG (5 parts by mass) were mixed at room temperature to prepare a resin composition (3).

[0232] A laminated film (thickness 800 μm) was obtained in the same manner as in Example 1, except that resin composition (3) was used instead of resin composition (1) as the resin constituting the first functional layer and the second functional layer, and the conditions for co-extrusion of the resins were changed so that the thicknesses of the first functional layer and the second functional layer were thicker than in Example 1 and the thicknesses of the inner layer and the outer layer were thinner than in Example 1. The laminated film (thickness 800 μm) was obtained in the same manner as in Example 1, and was composed of an inner layer (thickness 80 μm), a first functional layer (thickness 284 μm), a first adhesive layer (thickness 20 μm), an oxygen barrier layer (thickness 32 μm), a second adhesive layer (thickness 20 μm), a second functional layer (thickness 284 μm), and an outer layer (thickness 80 μm) stacked in the thickness direction in this order. The inner layer, the first functional layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, the second functional layer, and the outer layer are all unstretched layers.

[0233] The obtained laminated film was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0234] [Example 4] Except for using the resin composition (2) instead of the bPP as the resin constituting the inner layer and outer layer, the same method as in Example 3 was used to obtain a laminated film (thickness 800 μm) composed of an inner layer (thickness 80 μm), a first functional layer (thickness 284 μm), a first adhesive layer (thickness 20 μm), an oxygen barrier layer (thickness 32 μm), a second adhesive layer (thickness 20 μm), a second functional layer (thickness 284 μm), and an outer layer (thickness 80 μm) stacked in the thickness direction in this order. The inner layer, the first functional layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, the second functional layer, and the outer layer are all unstretched layers. The obtained laminated film was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0235] [Example 5] The bPP (88.6 parts by mass), the HMSPP (6.4 parts by mass), and the PG (5 parts by mass) were mixed at room temperature to prepare a resin composition (4).

[0236] Except for using resin composition (4) instead of resin composition (3) as the resin constituting the first functional layer and the second functional layer, the same method as in Example 3 was used to obtain a laminated film (thickness 800 μm) composed of an inner layer (thickness 80 μm), a first functional layer (thickness 284 μm), a first adhesive layer (thickness 20 μm), an oxygen barrier layer (thickness 32 μm), a second adhesive layer (thickness 20 μm), a second functional layer (thickness 284 μm), and an outer layer (thickness 80 μm) stacked in the thickness direction in this order. The inner layer, the first functional layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, the second functional layer, and the outer layer are all unstretched layers.

[0237] The obtained laminated film was evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0238] [Example 6] A laminated film having the structure shown in FIG. 2 was produced by the following procedure. That is, the bPP (91.5 parts by mass), the HMSPP (5 parts by mass), and the PG (3.5 parts by mass) were mixed at room temperature to prepare a resin composition (5).

[0239] By co-extruding the resin composition (5), the modified PP, the EVOH, the modified PP, and the resin composition (5) in this order, a laminated film (thickness 800 μm) was obtained, which was composed of a first functional layer (thickness 364 μm), a first adhesive layer (thickness 20 μm), an oxygen barrier layer (thickness 32 μm), a second adhesive layer (thickness 20 μm), and a second functional layer (thickness 364 μm) laminated in this order in the thickness direction. The first functional layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, and the second functional layer are all unstretched layers.

[0240] The obtained laminated film was evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0241] [Example 7] The hPP (88.6 parts by mass), the HMSPP (6.4 parts by mass), and the PG (5 parts by mass) were mixed at room temperature to prepare a resin composition (6).

[0242] Except for the fact that the hPP was used instead of the bPP as the resin constituting the inner layer and outer layer, and that the resin composition (6) was used instead of the resin composition (4) as the resin constituting the first functional layer and the second functional layer, a laminated film (thickness 800 μm) was obtained in the same manner as in Example 5, in which an inner layer (thickness 80 μm), a first functional layer (thickness 284 μm), a first adhesive layer (thickness 20 μm), an oxygen barrier layer (thickness 32 μm), a second adhesive layer (thickness 20 μm), a second functional layer (thickness 284 μm), and an outer layer (thickness 80 μm) were laminated in the thickness direction in this order. The inner layer, the first functional layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, the second functional layer, and the outer layer are all unstretched layers.

[0243] The obtained laminated film was evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0244] [Example 8] The hPP (91.5 parts by mass), the HMSPP (5 parts by mass), and the PG (3.5 parts by mass) were mixed at room temperature to prepare a resin composition (7).

[0245] Except for using resin composition (7) instead of resin composition (5) as the resin constituting the first functional layer and the second functional layer, the same method as in Example 6 was used to obtain a laminated film (thickness 800 μm) composed of a first functional layer (thickness 364 μm), a first adhesive layer (thickness 20 μm), an oxygen barrier layer (thickness 32 μm), a second adhesive layer (thickness 20 μm), and a second functional layer (thickness 364 μm) stacked in the thickness direction in this order. The first functional layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, and the second functional layer are all unstretched layers.

[0246] The obtained laminated film was evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0247] [Example 9] The bPP (85 parts by mass), the LDPE (10 parts by mass), and the PG (5 parts by mass) were mixed at room temperature to prepare a resin composition (8).

[0248] Except for using resin composition (8) instead of resin composition (3) as the resin constituting the first functional layer and the second functional layer, the same method as in Example 3 was used to obtain a laminated film (thickness 800 μm) composed of an inner layer (thickness 80 μm), a first functional layer (thickness 284 μm), a first adhesive layer (thickness 20 μm), an oxygen barrier layer (thickness 32 μm), a second adhesive layer (thickness 20 μm), a second functional layer (thickness 284 μm), and an outer layer (thickness 80 μm) stacked in the thickness direction in this order. The inner layer, the first functional layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, the second functional layer, and the outer layer are all unstretched layers.

[0249] The obtained laminated film was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0250] [Example 10] The bPP (83.4 parts by mass), the HMSPP (9.3 parts by mass), and the PG (7.3 parts by mass) were mixed at room temperature to prepare a resin composition (11).

[0251] A laminated film (thickness 800 μm) was obtained in the same manner as in Example 5, except that resin composition (11) was used instead of resin composition (4) as the resin constituting the first functional layer and the second functional layer, and the conditions for co-extrusion of the resins were changed so that the thicknesses of the first functional layer and the second functional layer were thinner than in Example 5 and the thicknesses of the inner layer and the outer layer were thicker than in Example 5. The laminated film (thickness 800 μm) was obtained in the same manner as in Example 5, and was composed of an inner layer (thickness 180 μm), a first functional layer (thickness 184 μm), a first adhesive layer (thickness 20 μm), an oxygen barrier layer (thickness 32 μm), a second adhesive layer (thickness 20 μm), a second functional layer (thickness 184 μm), and an outer layer (thickness 180 μm) stacked in the thickness direction in this order. The inner layer, the first functional layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, the second functional layer, and the outer layer are all unstretched layers.

[0252] The obtained laminated film was evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0253] [Comparative Example 1] The bPP (95 parts by mass) and the PG (5 parts by mass) were mixed at room temperature to prepare a resin composition (9).

[0254] Except for using resin composition (9) instead of resin composition (3) as the resin constituting the first functional layer and the second functional layer, the same method as in Example 3 was used to obtain a laminated film (thickness 800 μm) composed of an inner layer (thickness 80 μm), a first functional layer (thickness 284 μm), a first adhesive layer (thickness 20 μm), an oxygen barrier layer (thickness 32 μm), a second adhesive layer (thickness 20 μm), a second functional layer (thickness 284 μm), and an outer layer (thickness 80 μm) stacked in the thickness direction in this order. The inner layer, the first functional layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, the second functional layer, and the outer layer are all unstretched layers.

[0255] The obtained laminated film was evaluated in the same manner as in Example 1. The results are shown in Table 3.

[0256] [Comparative Example 2] The bPP (96.5 parts by mass) and the PG (3.5 parts by mass) were mixed at room temperature to prepare a resin composition (10).

[0257] Except for using the resin composition (10) instead of the resin composition (5) as the resin constituting the first functional layer and the second functional layer, the same method as in Example 6 was used to obtain a laminated film (thickness 800 μm) composed of a first functional layer (thickness 364 μm), a first adhesive layer (thickness 20 μm), an oxygen barrier layer (thickness 32 μm), a second adhesive layer (thickness 20 μm), and a second functional layer (thickness 364 μm) stacked in this order in the thickness direction. The first functional layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, and the second functional layer are all unstretched layers.

[0258] The obtained laminated film was evaluated in the same manner as in Example 1. The results are shown in Table 3.

[0259] [Table 1]

[0260] [Table 2]

[0261] [Table 3]

[0262] As is clear from the above results, in Examples 1 to 10, even though the main constituent material of the laminate film was polypropylene, the drawdown length of the laminate film was 42.8 mm or less (31.3 to 42.8 mm), and the drawdown length of the laminate film was short. These laminate films had excellent formability because the drawdown of the heated portion was suppressed during heat molding. Furthermore, the laminated films of Examples 1 to 10 had multiple resin layers mainly made of polyolefin (particularly polypropylene), and were therefore excellent in terms of reusability.

[0263] In Examples 1 to 10, the laminated film was stretched at a stretching speed of 50 to 70 s -1 The elongational viscosity at was 9400 Pa·s or more (9400 to 13000 Pa·s). In Examples 1 to 4 and 9, the laminated film was stretched at a stretching speed of 60 to 100 s -1 The extensional viscosity at was 10,000 Pa·s or more (10,000 to 13,000 Pa·s).

[0264] In Examples 1 to 4 and 9, the functional layers (first functional layer, second functional layer) in the laminated film contained a propylene-based polymer (P1) (bPP here) and an ethylene-based polymer (e1) (LDPE here), and in Examples 5 to 8 and 10, the functional layers (first functional layer, second functional layer) in the laminated film contained a propylene-based polymer (P1) (bPP here) and polypropylene (z1) (HMSPP here). In the functional layers (first functional layer, second functional layer) in the laminate films of Examples 1 to 10, the ratio of the combined content of the ethylene polymer (e1) and polypropylene (z1) (here, the combined content of LDPE and HMSPP) to the total mass of the functional layer was 5 mass% or more (5 to 19 mass%).

[0265] In the laminate films of Examples 1 to 10, the proportion of the polyolefin resin content relative to the total mass of the laminate film was 92 mass %.

[0266] In Examples 1 to 10, the elongation speed of the functional layers (first functional layer, second functional layer) in the laminated film was 60 to 100 s -1 The elongation viscosity at elongation speed is 10100 Pa s or more (10100 to 15000 Pa s), and the elongation speed is 50 to 70 s -1 The extensional viscosity at was 10100 Pa·s or more (10100 to 16000 Pa·s). The tensile impact strength of the laminated film in the direction perpendicular to the resin flow direction (TD) was 200 kJ / m in Examples 1 to 10. 2 or more (200~500kJ / m 2 ) and in particular, in Examples 1 to 6, 9, and 10, 280 kJ / m 2 or more (280~500kJ / m 2 ) was. The tensile impact strength of the laminated film in the resin flow direction (MD) in Examples 1 to 10 was 210 kJ / m 2 or more (210~600kJ / m 2 ), and in particular, in Examples 1 to 6, 9, and 10, it is 310 kJ / m 2 or more (310~600kJ / m 2) was.

[0267] In Examples 1 to 5, 7, 9, and 10, the laminated film further had an inner layer and an outer layer, the inner layer containing a propylene-based polymer (P2) (here, bPP), and the outer layer containing a propylene-based polymer (P3) (here, bPP). In particular, in Examples 2 and 4, the inner layer in the laminate film further contained an ethylene-based polymer (e2) (here, LDPE), and the outer layer in the laminate film further contained an ethylene-based polymer (e3) (here, LDPE). In Examples 1 to 5, 7, 9, and 10, the ratio of the total thickness of the functional layer, inner layer, and outer layer to the thickness of the laminated film was 91% or more.

[0268] In contrast, in Comparative Examples 1 and 2, since the main constituent material of the laminate film was polypropylene, the drawdown length of the laminate film was 51.5 mm or more (51.5 to 53.5 mm), and the drawdown length of the laminate film was long.During the heat molding of these laminate films, the drawdown of the heated portion was not suppressed, and the moldability was poor.

[0269] In Comparative Examples 1 and 2, the laminated film was stretched at a stretching speed of 50 to 70 s -1 The maximum value of the extensional viscosity at was 9300 Pa·s or less (the extensional viscosity was 8500 to 9300 Pa·s). In Comparative Examples 1 and 2, the laminated film was stretched at a stretching speed of 60 to 100 s -1 The elongational viscosity at was 9500 Pa·s or less (8200 to 9500 Pa·s).

[0270] The functional layers in the laminate films of Comparative Examples 1 and 2 did not contain either the ethylene polymer (e1) or the polypropylene (z1). [Industrial Applicability]

[0271] The present invention can be utilized in the production of packaging bodies involving thermoforming, and is suitable for use as a reusable resin film. [Explanation of symbols]

[0272] 1,2...Laminated film 11...functional layer, 111...first functional layer, 112...second functional layer 12. Oxygen barrier layer 13...Inner layer 14...outer layer 101...Packaging 7. Test piece 8...Lid material 10...Bottom material D: Drawdown length of laminated film

Claims

1. A laminated film having a functional layer and an oxygen barrier layer, the laminated film having an elongation rate of 50 to 70 s calculated by the Cogswell method from measurement data at a temperature of 240° C. when a twin capillary rheometer is used. －１ The laminate film has an elongational viscosity of 9,300 Pa·s or more at .

2. The functional layer contains a propylene-based polymer (P1), The elongation rate of 60 to 100 s calculated by the Cogswell method from the measurement data of the functional layer at a temperature of 240° C. when a twin capillary rheometer is used. －１ The laminate film according to claim 1 , wherein the functional layer has an elongational viscosity of 10,000 Pa·s or more at .

3. The laminate film according to claim 2, wherein the functional layer further comprises one or both of an ethylene-based polymer (e1) and a polypropylene (z1) as the propylene-based polymer (P1), and when the functional layer comprises the polypropylene (z1), the functional layer also comprises the propylene-based polymer (P1) other than the polypropylene (z1).

4. The laminate film according to claim 3, wherein the propylene-based polymer (P1) and the ethylene-based polymer (e1) have melt flow rates of 3 g / 10 min or less.

5. The elongation rate of 60 to 100 s calculated by the Cogswell method from the measurement data of the polypropylene (z1) at a temperature of 240° C. when a twin capillary rheometer is used. －１ The laminate film according to claim 3 or 4, wherein the polypropylene (z1) has an elongational viscosity of 10,000 Pa·s or more at .

6. An elongation rate of 60 to 100 s calculated by the Cogswell method from the measurement data of the ethylene polymer (e1) at a temperature of 240° C. when a twin capillary rheometer is used. －１ The laminated film according to claim 3 or 4, wherein the ethylene polymer (e1) has an elongational viscosity of 10,000 Pa·s or more at

7. The laminate film according to claim 3 or 4, wherein in the functional layer, the ratio of the total content of the polypropylene (z1) and the ethylene polymer (e1) to the total mass of the functional layer is 3 mass% or more.

8. 4. The laminate film according to claim 2, wherein the propylene-based polymer (P1) is either or both of a propylene-ethylene block copolymer and a homopolypropylene.

9. The laminated film further includes an inner layer as one of the outermost layers, 2. The laminate film according to claim 1, wherein the inner layer contains a propylene-based polymer (P2) and further contains one or both of an ethylene-based polymer (e2) and a polypropylene (z2) as the propylene-based polymer (P2), and when the inner layer contains the polypropylene (z2), the inner layer also contains the propylene-based polymer (P2) other than the polypropylene (z2).

10. The elongation rate of 60 to 100 s calculated by the Cogswell method from the measurement data of the polypropylene (z2) at a temperature of 240° C. when a twin capillary rheometer was used. －１ The laminated film according to claim 9, wherein the polypropylene (z2) has an elongational viscosity of 10,000 Pa·s or more at .

11. An elongation rate of 60 to 100 s calculated by the Cogswell method from measurement data of the ethylene polymer (e2) at a temperature of 240° C. when a twin capillary rheometer is used. －１ The laminate film according to claim 9 or 10, wherein the ethylene polymer (e2) has an elongational viscosity of 10,000 Pa·s or more at

12. The laminated film further includes an outer layer as the other outermost layer, 10. The laminate film according to claim 1 or 9, wherein the outer layer contains a propylene-based polymer (P3) and further contains one or both of an ethylene-based polymer (e3) and a polypropylene (z3) as the propylene-based polymer (P3), and when the outer layer contains the polypropylene (z3), the outer layer also contains the propylene-based polymer (P3) other than the polypropylene (z3).

13. The elongation rate of 60 to 100 s calculated by the Cogswell method from the measurement data of the polypropylene (z3) at a temperature of 240° C. when a twin capillary rheometer is used. －１ The laminated film according to claim 12, wherein the polypropylene (z3) has an elongational viscosity of 10,000 Pa·s or more at .

14. An elongation rate of 60 to 100 s calculated by the Cogswell method from measurement data of the ethylene polymer (e3) at a temperature of 240° C. when a twin capillary rheometer is used. －１ The laminate film according to claim 12, wherein the ethylene polymer (e3) has an elongational viscosity of 10,000 Pa·s or more at

15. the laminated film further comprises an inner layer as one outermost layer and an outer layer as the other outermost layer, the inner layer contains a propylene-based polymer (P2) and further contains one or both of an ethylene-based polymer (e2) and a polypropylene (z2) as the propylene-based polymer (P2), and when the inner layer contains the polypropylene (z2), the inner layer also contains the propylene-based polymer (P2) other than the polypropylene (z2); the outer layer contains a propylene-based polymer (P3) and further contains one or both of an ethylene-based polymer (e3) and a polypropylene (z3) as the propylene-based polymer (P3), and when the outer layer contains the polypropylene (z3), the outer layer also contains the propylene-based polymer (P3) other than the polypropylene (z3); 3. The laminate film according to claim 1, wherein a ratio of a total thickness of the functional layer, the inner layer and the outer layer to a thickness of the laminate film is 85% or more.

16. 3. The laminate film according to claim 1, wherein the content of the polyolefin resin in the laminate film is 80% by mass or more relative to the total mass of the laminate film.

17. The laminated film according to claim 1 or 2, wherein the oxygen barrier layer comprises an ethylene-vinyl alcohol copolymer.

18. The laminated film includes a pair of the functional layers, The laminated film according to claim 1 or 2, wherein the oxygen barrier layer is provided between a pair of the functional layers.

19. The tensile impact strength of the laminated film in a direction perpendicular to the flow direction of the resin is 190 kJ / m ２ The laminate film according to claim 1 or 2.

20. 3. The laminate film according to claim 1, wherein the drawdown length of the laminate film is 50 mm or less when the laminate film is heated at 400° C. for 120 seconds.

21. A packaging material formed using the laminate film according to claim 1 or 2.

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