Film manufacturing method, film, laminate, and packaging material

Abstract

To provide a film production method which is excellent in water vapor barrier property, tensile elongation and transparency.SOLUTION: A film production method melts a resin material containing polychlorotrifluoroethylene (PCTFE), extrudes the molten resin material in a fil shape from an extrusion die, brings the extrusion material into contact with a cooling roll having a surface temperature of 120°C or lower in the state where the surface temperature of the extrusion material is higher than a crystallization temperature of the PCTFE, molds a film raw fabric, heat-treats the film raw fabric at 80-200°C, and obtains a film.SELECTED DRAWING: None

Description

[Technical field]

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

[0002] Polychlorotrifluoroethylene (hereinafter, also referred to as "PCTFE") films are used for packaging pharmaceuticals, etc., due to their excellent water vapor barrier properties. For example, a laminate in which a layer made of PCTFE film and another layer are laminated is formed with pockets for accommodating capsules, etc., by drawing to form a base material for blister packaging. In recent years, there has been a demand for further improvement in the water vapor barrier properties of PCTFE films due to the need to improve the long-term storage properties of pharmaceuticals and other products and to use thinner films.

[0003] The following methods have been proposed to improve the water vapor barrier properties of PCTFE films. A method in which molten PCTFE is extruded and cooled to a temperature below the melting point to form a crystalline PCTFE film, and this film is then stretched under specified conditions (Patent Document 1). A method including a step of melting PCTFE and forming it into a film, a step of holding the formed film at 100 to 170°C, and a step of cooling the film after holding to room temperature, in which the temperature of the film is not allowed to drop below 170°C until the step of holding the formed film at 100 to 170°C is reached (Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2007-508962 [Patent Document 2] JP 2015-98168 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the method of Patent Document 1 has a problem in that the PCTFE film becomes hard due to stretching, and the tensile elongation decreases. Comparative Example 3 of Patent Document 2 shows that the stretched PCTFE film has a MD tensile elongation of 9% and a TD tensile elongation of 10%. If the tensile elongation of the PCTFE film is low, the PCTFE film will break when the PCTFE film or a laminate containing the same is drawn (poor drawing processability). In the method of Patent Document 2, the water vapor barrier property is improved by increasing the crystallinity of the PCTFE film. However, as the crystallinity increases, there is a problem that the haze of the PCTFE film increases (transparency decreases). When the transparency of the PCTFE film is low, the visibility of the contents packaged with the PCTFE film or a laminate containing the same decreases.

[0006] An object of the present invention is to provide a method for producing a film excellent in water vapor barrier property, tensile elongation and transparency. Another object of the present invention is to provide a film which is excellent in water vapor barrier properties, drawability and transparency and is useful as a packaging material, as well as a laminate and a packaging material which use the same. [Means for solving the problem]

[0007] The present invention provides a film production method, a film, a laminate, and a packaging material, each having the following features [1] to

[13] . [1] A resin material containing polychlorotrifluoroethylene is melted and extruded into a film from an extrusion die, and the extrudate is brought into contact with a cooling roll having a surface temperature of 120° C. or less while the surface temperature of the extrudate is higher than the crystallization temperature of the polychlorotrifluoroethylene, to form a raw film; A method for producing a film, comprising subjecting the raw film to a heat treatment at 80 to 200°C. [2] The method for producing a film according to [1], wherein the haze per 100 μm of thickness of the original film is 3% or less. [3] The method for producing a film according to [1] or [2], wherein the tensile elongation of the raw film in both MD and TD at 23°C is 30% or more. [4] The method for producing a film according to any one of [1] to [3] above, wherein the heat treatment is performed so that the density of the film after the heat treatment is 100.2 to 102.5% of the density of the original film. [5] The density of the film roll is 2.120 g / cm 3 The method for producing the film according to any one of the above [1] to [4], [6] The density of the film is 2.125 g / cm 3 The method for producing a film according to [5] above, wherein the heat treatment is carried out so as to obtain the above-mentioned results. [7] The method for producing a film according to any one of [1] to [6], further comprising winding the raw film into a roll and subjecting the wound raw film to the heat treatment. [8] The method for producing a film according to any one of [1] to [6], wherein the raw film is wound into a roll, and the heat treatment is performed while the wound raw film is unwound and transported, or while the raw film is transported without being wound. [9] Contains polychlorotrifluoroethylene, Water vapor transmission rate per 100μm thickness at 37.8℃ and 100% relative humidity is 0.07g / (m 2 · days) or less, The haze per 100 μm thickness is 3% or less, A film having a tensile elongation of 30% or more at 23°C in both MD and TD.

[10] Density is 2.125g / cm 3 The film according to [9] above.

[11] A laminate comprising a layer of the film according to [9] or

[10] and one or more other layers.

[12] A packaging material comprising the film of [9] or

[10] or the laminate of

[11] .

[13] The packaging material of

[12] , which is for blister packaging. Effect of the Invention

[0008] According to the film production method of the present invention, a film excellent in water vapor barrier property, tensile elongation and transparency can be produced. The film of the present invention is excellent in water vapor barrier property, tensile elongation and transparency. Therefore, the film of the present invention can provide a laminate and a packaging material that are excellent in water vapor barrier property, drawing processability and transparency. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating an example of a film raw web manufacturing apparatus. [Diagram 2] FIG. 1 is a diagram illustrating an example of a heat treatment apparatus. [Diagram 3] FIG. 13 is a diagram illustrating another example of a heat treatment apparatus. [Figure 4] FIG. 1 is a cross-sectional view illustrating a schematic example of a laminate of the present invention. [Diagram 5] FIG. 1 is a cross-sectional view illustrating an example of a blister package. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] As used herein, the following terms have the following meanings: The term "original film" refers to a film before post-processing (processing after film formation) such as heat treatment. The original film may be a long (strip-shaped) film or a sheet of film. "MD" means the machine direction, and "TD" means the transverse direction perpendicular to the MD. "Melting point" is the temperature corresponding to the maximum of the melting peak of a polymer as measured by differential scanning calorimetry (DSC). The "crystallization temperature" is the temperature corresponding to the maximum value of the exothermic peak that appears when a melted polymer is cooled at a rate of 10°C / min by the DSC method. The "Melt Volume Flow Rate" (MVR) of PCTFE is a value (mm 3 / sec) at 230℃ and pressure of 100kg / cm 2 The measurements were performed using an orifice with a length of 1 mm and an inner diameter of 1 mm. The "surface temperature of the extrudate" is a value measured by radiation thermometer. Specifically, it is a temperature measured using an infrared radiation thermometer with an emissivity setting of 0.85, at an angle of 30° to the surface of the object to be measured, and at a position about 20 cm away from the surface. In this application, the surface temperature of the extrudate refers to the value measured in TD, i.e., the center of the film width direction. The "surface temperature of the cooling roll" is a value measured using a contact type surface thermometer. The "water vapor transmission rate per 100 μm thickness" of the raw film and film (hereinafter collectively referred to as "film, etc.") is the water vapor transmission rate of the film, etc., when the thickness of the film, etc. is 100 μm. When the thickness of the film, etc. is different from 100 μm, it is the value calculated by the following formula 1. Water vapor permeability per 100 μm thickness = water vapor permeability of film, etc. × (thickness of film, etc. / 100 (μm)) Formula 1. The "thickness" of a film or the like is a value measured using a contact thickness meter. The "water vapor transmission rate" (hereinafter, also referred to as "WVTR") of a film or the like is a value measured according to the method (infrared sensor method) specified in JIS K 7129:2008 Appendix B. "Haze per 100 μm thickness" of a film, etc. is the haze of the film, etc., if the thickness of the film, etc. is 100 μm. If the thickness of the film, etc. is different from 100 μm, it is the value calculated by the following formula 2. Haze per 100 μm thickness = haze of film, etc. × (100 / thickness of film, etc. (μm)) Formula 2. "Haze" is a value measured at 23°C using CIE standard illuminant D65, which complies with JIS Z 8781-2:2012 (corresponding international standard ISO 11664-2:2007), in accordance with the method specified in JIS K 7136:2000 (corresponding international standard: ISO 14782:1999). "Tensile elongation" is a value measured at 23°C at a tensile speed of 200 mm / min on an ASTM V dumbbell-shaped test piece in accordance with ASTM D638. "Density" is a value measured in accordance with Method A (underwater displacement method) specified in JIS K 7112:1999. The dimensional ratios in FIGS. 1 to 5 are different from the actual ones for the sake of convenience of explanation.

[0011] [Film manufacturing method] In the film manufacturing method of the present invention, first, a raw film is molded from a resin material containing PCTFE (molding step), and then the raw film is subjected to a heat treatment (heat treatment step). The resin material may further contain additives, etc., as necessary. The resin material will be described in detail later.

[0012] (molding process) In the molding process, a resin material containing PCTFE is melted and extruded into a film from an extrusion die, and the extrudate is brought into contact with a cooling roll having a surface temperature of 120°C or lower while the surface temperature of the extrudate is higher than the crystallization temperature of PCTFE, to form a raw film. The extrudate that has been brought into contact with the cooling roll may be brought into contact with another cooling roll, the surface temperature of which is also set to 120° C. or lower. Hereinafter, the cooling roll that the extrudate extruded from the extrusion die contacts for the i-th time (i is an integer of 1 or more) will also be referred to as the "i-th cooling roll." For example, the cooling roll that the extrudate extruded from the extrusion die contacts for the first time (first time) will also be referred to as the first cooling roll.

[0013] An example of a method for forming an original film will be described with reference to FIG. FIG. 1 is a diagram showing a schematic diagram of an example of an apparatus 10 for producing a raw film. The manufacturing apparatus 10 includes an extruder (not shown), an extrusion die 11 attached to the extruder, a first cooling roll 12 having a surface temperature of 120°C or lower, a second cooling roll 13 arranged behind the first cooling roll, and a pair of nip rolls 14 arranged behind the first cooling roll. The first cooling roll 12 and the second cooling roll 13 are arranged in series so that the extrudate 1 (molten resin material) extruded from the extrusion die 11 passes through the first cooling roll 12 and the second cooling roll 13 sequentially toward the pair of nip rolls 14.

[0014] As the extruder, a known extruder such as a single screw extruder or a twin screw extruder can be used. As the extrusion die 11, a known extrusion die such as a T-die (flat die) can be used. The first cooling roll 12 and the second cooling roll 13 may each be a known cooling roll as long as the surface temperature can be controlled.

[0015] Although an example in which the manufacturing apparatus 10 includes two cooling rolls 12 and 13 has been shown here, the number of cooling rolls included in the manufacturing apparatus 10 is not limited to two, and may be one, or three or more. The manufacturing apparatus 10 may further include a take-up roll downstream of the pair of nip rolls 14. A pressing roll may be disposed at a position opposite to the first cooling roll, and the extrudate may be pressed against the first cooling roll by the pressing roll when the extrudate comes into contact with the first cooling roll.

[0016] In the manufacturing apparatus 10, the raw film is formed in the following manner. A resin material containing PCTFE is melted by an extruder (not shown), and the melted resin material is supplied to an extrusion die 11 and extruded into a film form from the extrusion die 11. Next, the extrudate 1 extruded from the extrusion die 11 is successively brought into contact with a first cooling roll 12 and a second cooling roll 13, and is conveyed by passing between a pair of nip rolls 14. The extrudate 1 is cooled by contact with the cooling rolls 12 and 13, and the film shape is fixed, thereby obtaining a long raw film 2. The extrudate 1 is typically conveyed so that one side and the other side of the extrudate 1 are alternately brought into contact with the multiple cooling rolls 12 and 13. If necessary, the raw film 2 may be wound around a winding roll into a roll shape, or the raw film 2 may be cut into sheets.

[0017] The temperature inside the extruder (the temperature at which the resin material is melted) and the temperature of the extrusion die 11 may be any temperature at which PCTFE is melted. These temperatures are typically equal to or higher than the melting point of PCTFE, and preferably equal to or higher than the melting point of PCTFE (40°C to 130°C). If the temperature inside the extruder and the temperature of the extrusion die 11 are not less than the lower limit, the melt can be extruded stably, whereas if they are not more than the upper limit, deterioration of the material due to thermal decomposition can be suppressed.

[0018] The extrudate 1 is brought into contact with the first cooling roll 12 in a state in which the surface temperature of the extrudate 1 is higher than the crystallization temperature of PCTFE. In addition, the surface temperature of the first cooling roll 12 is set to 120° C. or lower. As a result, when the extrudate 1 is brought into contact with the first cooling roll 12, the extrudate 1 is rapidly cooled, and the crystallinity of the original film roll 2 is reduced. Since the original film roll 2 has a low crystallinity, the haze of the original film roll 2 is low. Furthermore, since the original film roll 2 has a low crystallinity and contains a large amount of amorphous parts, the tensile elongation at 23°C is high. Such low haze and high tensile elongation are sufficiently maintained even after heat treatment.

[0019] The surface temperature of the extrudate 1 at the time of contact with the first cooling roll 12 (hereinafter also referred to as “T1”) and the surface temperature of the first cooling roll 12 (hereinafter also referred to as “T r1 ") is set according to the desired crystallinity of the raw film 2, and further according to the desired haze, tensile elongation, etc. of the raw film 2.

[0020] T r1 is 120° C. or less in order to reduce the crystallinity of the film roll 2. r1is preferably 100°C or less, more preferably 80°C or less. r1 The lower limit is, for example, 20°C.

[0021] T1 is higher than the crystallization temperature of PCTFE in order to reduce the crystallinity of the raw film 2. T1 is preferably (PCTFE crystallization temperature + 10°C) or higher, and particularly preferably (PCTFE crystallization temperature + 30°C) or higher. The upper limit of T1 is, for example, (PCTFE melting point + 110°C).

[0022] T1 and T r1 Difference between (T1-T r1 ) is preferably 100° C. or higher, particularly preferably 140° C. or higher, in order to reduce the crystallinity of the film 2. r1 The upper limit is, for example, 300°C.

[0023] T1 can be adjusted by the temperature of the extrusion die 11, the distance from the exit A of the extrusion die 11 to the contact point B where the extrudate 1 first comes into contact with the first cooling roll 12 (hereinafter also referred to as the "AB distance"), the molding speed (extrusion speed), etc.

[0024] The extrusion speed is preferably 1 to 50 m / min, particularly preferably 2 to 40 m / min. When the extrusion speed is equal to or higher than the lower limit, transparency and productivity are good. When the extrusion speed is equal to or lower than the upper limit, thermal deterioration due to shear heat caused by an increase in the extrusion amount of the extrudate 1 can be suppressed.

[0025] The distance between AB is preferably 400 mm or less, particularly preferably 250 mm or less. If the distance between AB is equal to or less than the upper limit, it is easy to make T1 higher than the crystallization temperature of PCTFE. The lower limit of the distance between AB is, for example, 20 mm.

[0026] The surface temperature of the second cooling roll 13 (hereinafter, “T r2 " is also written.) is 120℃ or less. T r2 is T r1 may be the same as or different from. T r2Typically, T r1 Lower than. T r2 The lower limit is, for example, 20°C.

[0027] (film roll) The thickness of the raw film 2 is, for example, 6 to 500 μm, and can be appropriately selected in consideration of the thickness of the film to be produced.

[0028] The haze per 100 μm of the original film 2 is preferably 3% or less, and particularly preferably 2% or less. If the haze per 100 μm of the original film 2 is equal to or less than the upper limit, the degree of crystallization is low and the haze per 100 μm of the film obtained by heat treating the original film 2 is easily set to 3% or less. The lower limit of the haze per 100 μm thickness of the raw film 2 is, for example, 0.1%.

[0029] The tensile elongation in each of the MD and TD of the raw film 2 at 23° C. is preferably 30% or more, particularly preferably 70% or more. If the tensile elongation is 30% or more, the film obtained by heat treating the raw film 2 has excellent tensile elongation in each of the MD and TD at 23° C. The upper limit of the tensile elongation of the raw film 2 at 23° C. in each of the MD and TD is, for example, 350%. As a method for increasing the tensile elongation of the film raw material 2, the above-mentioned T1 and T r1 and a method of heating the extrudate by installing a far-infrared heater between the extrusion die and the cooling roll.

[0030] The density of film roll 2 is 2.120 g / cm 3 The following is preferred: 2.118 g / cm 3 The following is particularly preferred: The density of the film roll 2 is 2.120 g / cm 3 If it is equal to or less than this, the crystallinity of the raw film 2 is sufficiently low, and the haze per 100 μm in thickness and the tensile elongation in the MD and TD are easily adjusted to the above-mentioned preferred values. The lower limit of the density of the film roll 2 is, for example, 2.110 g / cm 3It is.

[0031] (Heat treatment process) In the heat treatment step, the raw film is subjected to a heat treatment. Examples of the heat treatment method include the following Method I, Method II, and Method III. Method I: A method in which the original film is wound into a roll and the wound original film is subjected to a heat treatment. Method II: A method in which the original film is wound into a roll and heat treatment is carried out while the wound original film is unwound and transported, or while the original film is transported without being wound up. Method III: A method in which the original film roll is cut into sheets and the sheets are subjected to a heat treatment.

[0032] In the case of method I, for example, a take-up roll is disposed downstream of the pair of nip rolls 14 of the above-mentioned manufacturing apparatus 10, and the film roll 2 that has passed between the pair of nip rolls 14 is taken up onto the take-up roll, and the taken-up film roll 2 is then placed in a heat treatment apparatus and heat-treated.

[0033] FIG. 2 shows a schematic configuration of an example of a heat treatment apparatus used in Method I. The heat treatment device 20 shown in Figure 2 includes a thermostatic chamber 22 that houses the film roll 2 wound into a roll around a winding roll 21, a pair of hanging devices 23 that extend downward from the top of the thermostatic chamber 22 and hold both ends of the winding roll 21 at their tip portions, and a hot air circulation section (not shown) that circulates hot air within the thermostatic chamber 22.

[0034] The heat treatment using the heat treatment apparatus 20 is performed, for example, in the following procedure. The original film roll 2 wound in a roll shape around a take-up roll 21 is housed in a thermostatic chamber 22 of a heat treatment device 20, and the original film roll 2 is suspended by holding both ends of the take-up roll 21 with a pair of hanging tools 23. Next, hot air is circulated in the thermostatic chamber 22 by a hot air circulation unit to heat-treat the original film roll 2, and a film 3, which is the heat-treated original film roll 2, is obtained.

[0035] In method I, the heat treatment means is not limited to hot air, but may be steam, hot water, a heat medium, far-infrared heating, etc. Instead of the thermostatic bath, a pressurized steam container, a hot water bath, a heat medium bath, a far-infrared heating furnace, etc. may be used.

[0036] In the case of method II, for example, a take-up roll is disposed downstream of the pair of nip rolls 14 of the above-mentioned manufacturing apparatus 10, and the film roll 2 that has passed between the pair of nip rolls 14 is taken up onto the take-up roll, and then the taken-up film roll 2 is unwound and introduced into a heat treatment device, and is heat-treated while being transported to MD by roll-to-roll.

[0037] FIG. 3 shows a schematic configuration of an example of a heat treatment apparatus used in Method II. 3 includes an unwinding roll 31 that sequentially unwinds the original film web 2 wound into a roll, a heat treatment section 32 that heat-treats the original film web 2, a plurality of transport rolls 33, and a take-up roll 34 that winds up the film 3, which is the heat-treated original film web 2. A space S is formed in the heat treatment section 32, into which the original film web 2 is transported, and a plurality of transport rolls 33 are disposed within the space S. In addition, a heating mechanism (not shown) for heating the original film web 2 introduced into the space S is provided in the heat treatment section 32.

[0038] The heat treatment using the heat treatment apparatus 30 is performed, for example, in the following procedure. The film roll 2 wound into a roll is transferred to the unwinding roll 31 of the heat treatment device 30, unwound from the unwinding roll 31 and transported to the heat treatment device 32, where it is heat-treated by a heating mechanism to turn the film roll 2 into film 3, and the film 3 is wound around a winding roll 34.

[0039] Instead of performing the heat treatment as described above, a heat treatment device may be disposed downstream of the manufacturing apparatus 10, and the raw film 2 that has passed between a pair of nip rolls 14 may be introduced into the heat treatment device without being wound up, and may be heat-treated while being transported to MD by roll-to-roll. Instead of transporting the original film roll from roll to roll, it may be transported on a conveyer. After the heat treatment, the heat-treated raw film may be wound up on a take-up roll into a roll, or may be cut into sheets, as necessary.

[0040] In the case of method III, the sheet of film may be heat-treated while being placed on a fixed table, or may be heat-treated while being conveyed on a conveyer.

[0041] When the raw film is heat-treated while being transported (for example, when the heat treatment method is Method II), the tension applied to the raw film during heat treatment is preferably 100 N / m or less. The tension may be 0 N / m. When the tension is equal to or less than the upper limit, the raw film is stretched during heat treatment, the film becomes hard, and the tensile elongation in MD and TD is prevented from decreasing. The tension can be determined indirectly or directly from a converted value from the brake torque or a tension meter installed on a roll along the way.

[0042] The heat treatment temperature for the raw film is 80 to 200°C. If the heat treatment temperature is 80°C or higher, the density of the film roll increases, which makes it difficult for water vapor to pass through and reduces the WVTR. Also, since the temperature is below the crystallization temperature, the haze can be maintained at almost the same value as the original film roll. On the other hand, if the density is too high, the raw film becomes hard and the tensile elongation in both MD and TD decreases. If the heat treatment temperature is 200° C. or less, the tensile elongation in both MD and TD of the raw film can be sufficiently maintained. Therefore, if the heat treatment temperature is from 80 to 200° C., a film excellent in water vapor barrier properties, transparency and tensile elongation can be obtained. The reason why the density of the original film increases by heat treatment is believed to be that the molecules that are partially sparsely arranged due to processing stress during molding of the original film are compressed by heat treatment.

[0043] When the heat treatment is performed without transporting the raw film (for example, when the heat treatment method is Method I), the heat treatment temperature is preferably 80 to 200° C., particularly preferably 100 to 180° C. The heat treatment time is preferably 0.5 to 168 hours, more preferably 2 to 48 hours. When the raw film is heat-treated while being transported (for example, when the heat treatment method is Method II), the heat treatment temperature is preferably 90 to 200° C., particularly preferably 120 to 200° C. The heat treatment time is preferably 5 to 1800 seconds, more preferably 10 to 600 seconds.

[0044] The heat treatment of the raw film obtained in the molding step is preferably carried out so that the density of the film after the heat treatment is 100.2 to 102.5% of the density (100%) of the raw film. The density of the film is more preferably 100.5 to 102.2% of the density of the raw film, and particularly preferably 100.9 to 102.0%. When the density of the film is within this range, it is possible to reduce the WVTR and the tensile elongation within the target range. In addition, the density of the film obtained in the molding process was 2.120 g / cm 3 If the density of the film after heat treatment is less than 2.125 g / cm3, the density of the film after heat treatment and the density of the final film are less than 2.125 g / cm3. 3 It is preferable that the density of the film is 2.125 g / cm or more. 3 If it is equal to or greater than this, the water vapor barrier property and transparency will be more excellent. The density of the film roll is 2.120g / cm 3 If the density is less than 2.173 g / cm3, the upper limit of the density of the film after heat treatment is, for example, 2.173 g / cm3. 3 It is. The density of the film can be adjusted by the density of the raw film, the heat treatment temperature and the heat treatment time. The higher the heat treatment temperature or the longer the heat treatment time, the higher the density of the film tends to be.

[0045] After the heat treatment step of the raw film, the obtained film may be subjected to further post-processing other than heat treatment (hereinafter also referred to as "other post-processing") to obtain a final product. Other post-processing steps include cutting the film, stretching, surface treatment, printing, and coating. Since the stretching treatment tends to reduce the tensile elongation in MD and TD of the film, it is preferable not to perform the stretching treatment. If the stretching treatment is performed, it is preferable to set the stretching conditions so that the tensile elongation of the film in MD and TD at 23°C after the stretching treatment is not less than 30%.

[0046] (Resin material) The resin material includes PCTFE. The PCTFE in the present invention is a polymer containing units (hereinafter also referred to as "CTFE units") based on chlorotrifluoroethylene (hereinafter also referred to as "CTFE"). PCTFE may contain units based on other monomers copolymerizable with CTFE. The units based on other monomers in PCTFE may be of one type or of two or more types.

[0047] Examples of other monomers include fluoromonomers other than CTFE and monomers that do not have a fluorine atom (hereinafter also referred to as "non-fluorine monomers"). Examples of fluoromonomers other than CTFE include fluoroolefins such as vinyl fluoride, vinylidene fluoride, trifluoroethylene, tetrafluoroethylene, hexafluoropropylene, and hexafluoroisobutylene, perfluoro(alkyl vinyl ethers), fluorovinyl ethers having a functional group, fluoro(divinyl ethers), polyfluoro(alkyl ethylenes), and fluoromonomers having a ring structure.

[0048] Examples of perfluoro(alkyl vinyl ether) include CF2=CFOCF3, CF2=CFOCF2CF3, CF2=CFOCF2CF2CF3, CF2=CFOCF2CF2CF2CF3, and CF2=CFO(CF2)6F. Examples of polyfluoro(alkylethylene)s include CH2=CF(CF2)2F, CH2=CF(CF2)3F, CH2=CF(CF2)4F, CH2=CF(CF2)5F, CH2=CF(CF2)6F, CH2=CF(CF2)2H, CH2=CF(CF2)3H, CH2=CF(CF2)4H, CH2=CF(CF2)5H, CH2=CF(CF2)6H, CH2=CH(CF2)2F, CH2=CH(CF2)3F, CH2=CH(CF2)4F, CH2=CH(CF2)5F, CH2=CH(CF2)6F, CH2=CH(CF2)2H, CH2=CH(CF2)3H, CH2=CH(CF2)4H, CH2=CH(CF2)5H, and CH2=CH(CF2)6H.

[0049] Examples of fluorovinyl ethers having functional groups include CF2=CFOCF2CF(CF3)OCF2CF2SO2F, CF2=CFOCF2CF2SO2F, CF2=CFOCF2CF(CF3)OCF2CF2SO3H, CF2=CFOCF2CF2SO3H, CF2=CFO(CF2)3COOCH3, and CF2=CFO(CF2)3COOH. Examples of fluoro(divinyl ether) include CF2=CFCF2CF2OCF=CF2, CF2=CFCF2OCF=CF2, CF2=CFO(CF2)3OCF=CF2, CF2=CFO(CF2)4OCF=CF2, and CF2=CFO(CF2)6OCF=CF2. Examples of fluoromonomers having a ring structure include perfluoro(2,2-dimethyl-1,3-dioxole), 2,2,4-trifluoro-5-trifluoromethoxy-1,3-dioxole, and perfluoro(2-methylene-4-methyl-1,3-dioxolane).

[0050] Examples of the non-fluorine monomer include a monomer having at least one functional group selected from the group consisting of a carbonyl group-containing group, a hydroxy group, an epoxy group, an amide group, an amino group, and an isocyanate group, and not containing a fluorine atom (hereinafter also referred to as a "functional monomer"), an olefin (e.g., ethylene), and a vinyl ester (e.g., vinyl acetate).

[0051] From the viewpoint of adhesion at the interface with other layers, the functional group of the functional monomer is preferably a carbonyl-containing group, such as a keto group, a carbonate group, a carboxy group, a haloformyl group, an alkoxycarbonyl group, or an acid anhydride group. The keto group is preferably contained between carbon atoms in an alkylene group having 2 to 8 carbon atoms. The number of carbon atoms in the alkylene group does not include the carbon atom in the keto group. The alkylene group may be linear or branched. Examples of the haloformyl group include -C(=O)F, -C(=O)Cl, -C(=O)Br and -C(=O)I, and -C(=O)F is preferred. The alkoxy group in the alkoxycarbonyl group is preferably an alkoxy group having 1 to 8 carbon atoms, and particularly preferably a methoxy group or an ethoxy group. The carbonyl group-containing group is preferably an acid anhydride group or a carboxy group.

[0052] Examples of functional monomers include monomers having a carboxy group, such as maleic acid, itaconic acid, citraconic acid, and undecylenic acid, monomers having an acid anhydride group, such as itaconic anhydride (hereinafter also referred to as "IAH"), citraconic anhydride (hereinafter also referred to as "CAH"), 5-norbornene-2,3-dicarboxylic anhydride (hereinafter also referred to as "NAH"), and maleic anhydride, hydroxyalkyl vinyl ether, and epoxyalkyl vinyl ether, with monomers having a carboxy group and monomers having an acid anhydride group being preferred. The monomer having an acid anhydride group is preferably IAH, CAH or NAH. The functional group monomer may be used alone or in combination of two or more kinds.

[0053] Functional groups may be present as end groups on the polymer backbone of the PCTFE. PCTFE, in which functional groups exist as terminal groups on the polymer main chain, can be obtained by polymerization using a chain transfer agent or polymerization initiator that provides the functional groups. Examples of chain transfer agents that provide functional groups include acetic acid, acetic anhydride, methyl acetate, ethylene glycol, and propylene glycol. Examples of polymerization initiators that provide functional groups include di-n-propyl peroxydicarbonate, diisopropyl peroxycarbonate, tert-butyl peroxyisopropyl carbonate, bis(4-tert-butylcyclohexyl) peroxydicarbonate, and di-2-ethylhexyl peroxydicarbonate.

[0054] The proportion of CTFE units in the total of all units constituting PCTFE is preferably 90 to 100 mol%, more preferably 95 to 100 mol%, particularly preferably 97 to 100 mol%, and most preferably 100 mol% (CTFE homopolymer). If the proportion of CTFE units is equal to or greater than the lower limit, the water vapor barrier property of the film is more excellent.

[0055] The MVR of PCTFE is 1 to 400 mm. 3 / sec is preferred, 5 to 350 mm 3 / sec is more preferable, 10 to 300 mm 3 When the MVR is equal to or greater than the lower limit, a film having excellent moldability, surface smoothness, and appearance is easily obtained. When the MVR is equal to or less than the upper limit, a film having excellent mechanical strength is easily obtained.

[0056] The melting point of PCTFE is preferably 200 to 225° C., particularly preferably 205 to 220° C. When the melting point of PCTFE is equal to or higher than the lower limit, the heat resistance of the film is excellent. When the melting point of PCTFE is equal to or lower than the upper limit, the raw film can be easily formed.

[0057] The resin material may further contain additives, etc., as necessary, within the scope of not impairing the effects of the present invention. Examples of additives include colorants such as organic pigments and inorganic pigments, heat stabilizers such as copper oxide, and antistatic agents such as ionic liquids.

[0058] The proportion of PCTFE in the total mass of the resin material is preferably 97 to 100 mass%, more preferably 99 to 100 mass%, further preferably 99.5 to 100 mass%, and particularly preferably 99.7 to 100 mass%. When the proportion of PCTFE is equal to or more than the lower limit, the water vapor barrier property of the film is more excellent.

[0059] (Action and effect) In the film manufacturing method of the present invention, a resin material containing PCTFE is melted and extruded into a film shape from an extrusion die, and the extrudate is brought into contact with a cooling roll having a surface temperature of 120° C. or less while the surface temperature of the extrudate is higher than the crystallization temperature of the polychlorotrifluoroethylene, to form a raw film, and the raw film is heat-treated at 80 to 200° C., so that the crystallinity can be appropriately controlled. Therefore, the obtained film is considered to have excellent water vapor barrier properties, tensile elongation, and transparency.

[0060] 〔film〕 The films of the present invention comprise PCTFE. PCTFE is as described above.

[0061] The film of the present invention may further contain additives, etc., as necessary, within the range that does not impair the effects of the present invention. The additives are as described above.

[0062] The proportion of PCTFE in the total mass of the film is preferably 97 to 100 mass%, more preferably 99 to 100 mass%, further preferably 99.5 to 100 mass%, and particularly preferably 99.7 to 100 mass%. When the proportion of PCTFE is equal to or more than the lower limit, the water vapor barrier property of the film is more excellent.

[0063] The thickness of the film of the present invention is, for example, 6 to 500 μm, and can be appropriately selected taking into consideration the application of the film, the desired WVTR, and the like. For example, when a layer made of the film of the present invention is laminated with another layer to form a laminate and the laminate is used for blister packaging, the thickness of the layer made of the film is preferably 6 to 100 μm.

[0064] The WVTR of the film of the present invention at 37.8°C and 100% relative humidity per 100 μm thickness is 0.07 g / (m 2 ·day) or less, and is 0.06g / (m 2 ·day) or less is preferable, and 0.05g / (m 2 The smaller the WVTR, the more excellent the water vapor barrier property. The smaller the WVTR, the better in terms of water vapor barrier properties. However, as the WVTR decreases, the tensile elongation tends to decrease. Therefore, the WVTR at a relative humidity of 100% is 0.02 g / (m 2 ·day) or more is preferable, and 0.03g / (m 2 -days) or more is preferable. In terms of the balance between the water vapor barrier property and the tensile elongation, the WVTR is 0.02 to 0.07 g / (m 2 ·day), and 0.03 to 0.06 g / (m 2 -Sun) is particularly preferred.

[0065] The haze per 100 μm of the film of the present invention is 3% or less, preferably 2% or less, particularly preferably 1% or less, and most preferably 0.5% or less. The lower the haze, the more excellent the transparency.

[0066] The tensile elongation in each of the MD and TD of the film of the present invention at 23° C. is 30% or more, preferably 50% or more, and particularly preferably 70% or more. When the tensile elongation is 30% or more, the film of the present invention or a laminate obtained by laminating the film of the present invention and another layer is hardly broken when the film is drawn, and the film or laminate has excellent drawing processability. The upper limit of the tensile elongation in each of the MD and TD of the film is, for example, 350%.

[0067] The density of the film of the present invention is 2.125 g / cm 3 More than 2.135 g / cm is preferable. 3 The above is particularly preferred. The density of the film is 2.125 g / cm 3 If it is equal to or greater than this, the water vapor barrier property of the film is excellent. The density of the film is 2.165g / cm 3 The following is preferred: 2.160 g / cm 3 The following is particularly preferred: the density of the film is 2.165 g / cm 3 If it is equal to or less, the tensile elongation in the MD and TD of the film will be excellent.

[0068] The film of the present invention can be produced by the above-mentioned film production method of the present invention.

[0069] [Laminate] The laminate of the present invention is a laminate comprising a layer made of the above-mentioned film of the present invention and one or more other layers. In the laminate of the present invention, each of the layer made of the film of the present invention and the other layers may be one layer or two or more layers. The total number of layers constituting the laminate of the present invention is, for example, 2 to 5.

[0070] FIG. 4 is a cross-sectional view that illustrates an example of the laminate of the present invention. Laminate 40 shown in FIG. 4 is a laminate in which layer 41 made of the film of the present invention, adhesive layer 45 (another layer), and base layer 43 (another layer) are laminated in this order.

[0071] Examples of materials constituting the base layer 43 include polypropylene, polyvinyl chloride, polyvinylidene chloride, cyclic olefin polymer, and unstretched polyethylene terephthalate. The thickness of the base layer 43 is, for example, 100 to 1000 μm.

[0072] Examples of the adhesive that constitutes the adhesive layer 45 include a urethane adhesive and a polyester adhesive. The adhesive layer 45 has a thickness of, for example, 1 to 10 μm.

[0073] The laminate 40 can be produced, for example, by bonding a layer made of the film of the present invention and a base layer 43 together using an adhesive. The film of the present invention can be produced by the above-mentioned film production method of the present invention. In order to improve the adhesion between the layer made of the film of the present invention and other layers, before laminating other layers, the film of the present invention or the base layer 43 may be subjected to a surface treatment. Examples of the surface treatment include plasma treatment, corona treatment, and ultraviolet treatment. As a method for bonding the film of the present invention and the base layer 43, a known lamination method such as a dry lamination method or a wet lamination method can be used.

[0074] [Packaging material] The packaging material of the present invention comprises the film of the present invention or the laminate of the present invention. The packaging material of the present invention is preferably a packaging material for blister packaging, since the film of the present invention is excellent in water vapor barrier properties, transparency and tensile elongation.

[0075] Fig. 5 is a cross-sectional view showing an example of a package that contains contents in a blister package. Fig. 5 shows a state in which contents are contained in the package. Examples of the contents include drug capsules. The packaging body 50 shown in FIG. The container 51 has one or more pockets 51a. The pockets 51a have a recess that opens to one side of the container 51. The recess is adapted to accommodate the contents 60. The pockets 51a are formed to protrude to the other side of the container 51. The lid member 53 is laminated on one side of the container 51 and seals the opening of the recess of the pocket portion 51a.

[0076] The packaging material of the present invention, for example, the laminate 40 described above, can be drawn by a known method to form a pocket portion 51a, thereby making a container 51. When forming the pocket portion 51a in the laminate 40, the pocket portion 51a is usually formed so that the layer 41 made of the film of the present invention faces inward (the lid material 53 side). A known blister packaging lid material can be used as the lid material 53. For example, a lid material having a base material such as aluminum foil and a heat seal layer laminated on one surface (container 51 side) of the base material can be used. EXAMPLES

[0077] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following description. Among Examples 1 to 6 described below, Examples 1 to 4 are working examples, and Examples 5 and 6 are comparative examples. The measurement or evaluation methods and materials used in each example are shown below.

[0078] (Measurement method) <mvr> MVR of PCTFE (mm 3 / sec) was measured according to the method specified in JIS K 7210-1:2014 (corresponding international standard ISO 1133-1:2011) at a temperature of 230°C and a pressure of 100 kg / cm 2 The measurements were performed under the condition of L / D = 1 / 1 mm.

[0079] <Melting point, crystallization temperature> The melting point of PCTFE was measured using a differential scanning calorimeter (Seiko Instruments Inc., DSC7020) at a temperature increase rate of 10° C. / min. The crystallization temperature of PCTFE was defined as the position of the exothermic peak when once-melted PCTFE was measured at a temperature drop rate of 10° C. / min using a differential scanning calorimeter (DSC7020, manufactured by Seiko Instruments Inc.). Specifically, 10±0.2 mg of the sample was weighed into an aluminum pan, which was then covered with an aluminum cap and sealed. Similarly, 10±0.2 mg of alumina, which is a comparative material, was weighed, which was then covered with an aluminum cap and sealed. The sample and comparative material prepared above were set in a differential scanning calorimeter, and the temperature was raised from 30°C to 270°C at 10°C / min, held for 5 minutes, and then cooled to 120°C or less at a cooling rate of 10°C / min. The temperature corresponding to the maximum melting peak appearing during the heating process of the DSC curve obtained at this time was defined as the melting point. In addition, the temperature corresponding to the exothermic peak temperature appearing during the cooling process was defined as the crystallization temperature.

[0080] <Surface temperature of extrudate and cooling roll> The surface temperature of the extrudate was measured using an infrared radiation thermometer (SK-8900 manufactured by Sato Keiryoki Seisakusho Co., Ltd.) at an emissivity setting of 0.85, at an angle of 30° to the surface of the extrudate, and at a position approximately 20 cm away from said surface. In this application, the surface temperature of the extrudate refers to the measurement value at the center part in the film width direction. The surface temperature of the cooling roll was measured using a contact type surface thermometer (HA-200E manufactured by Anritsu Keiki Co., Ltd.).

[0081] <Thickness> The thickness of the film etc. was measured using a contact type thickness meter (micrometer manufactured by Mitutoyo Corporation).

[0082] <wvtr> The water vapor transmission rate (WVTR) of films and the like was measured at 37.8°C and 100% RH using a water vapor transmission rate measuring device (PERMATRAN-W3 / 31, manufactured by MOCON Inc.) according to the method specified in JIS K 7129:2008 Appendix B.

[0083] <Haze> The haze of films, etc. was measured at 23°C using a haze meter (NDH-5000, manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with the method specified in JIS K 7136:2000 (corresponding international standard: ISO 14782:1999) using CIE standard illuminant D65, which complies with JIS Z 8781-2:2012 (corresponding international standard ISO 11664-2:2007).

[0084] <Tensile elongation> The tensile elongation of the film or the like was measured at 23° C. at a tensile speed of 200 mm / min using an ASTM V dumbbell-shaped test piece in accordance with ASTM D638.

[0085] <density> Density of film, etc. (g / cm 3 ) was measured using an automatic density meter (DMA-220, manufactured by Shinko Denshi Co., Ltd.) in accordance with Method A (underwater displacement method) specified in JIS K 7112:1999.

[0086] (Production Example 1: Synthesis of PCTFE) After evacuating the inside of a 2.5L stainless steel polymerization tank, 1000g of deionized water was charged as a solvent, 4.0g of potassium persulfate as an initiator, and 555g of chlorotrifluoroethylene (CTFE), and the internal temperature was adjusted to 50°C. The pressure at that time was 1.17MPaG. "G" in "MPaG" indicates gauge pressure. Next, an aqueous solution of sodium hydrogen sulfite (8.6 g of sodium hydrogen sulfite, 100 g of deionized water) was added to initiate polymerization. The addition was carried out for 4 hours at a rate of 7.4 cc / hour, and 7 hours after the start of the addition, the mixture was cooled, and the unreacted CTFE was purged. The polymer was then removed from the polymerization tank, washed, and dried to obtain 105 g of PCTFE. The MVR of the obtained PCTFE is 75 mm 3 / sec, the melting point was 211°C, and the crystallization temperature was 186°C.

[0087] (Examples 1 to 4) A film roll was formed by the following procedure using a manufacturing apparatus having the same configuration as the manufacturing apparatus 10 shown in Fig. 1. A single screw extruder with a barrel diameter of 30 mm was used as the extrusion die 11. A film die with a nozzle width of 250 mm was used as the extrusion die 11. The PCTFE of Production Example 1 was melted in an extruder and extruded from an extrusion die 11 to form a film-like extrudate, which was then passed through a first cooling roll 12, a second cooling roll 13, and a nip roll 14 in sequence to fix the film shape, thereby obtaining a film roll having a thickness of 100 μm. The temperature of the extrusion die 11 was 300° C., the distance from the exit of the extrusion die 11 to the first cooling roll 12 (distance between A and B) was 45 mm, the surface temperature of the first cooling roll 12 was 90° C., the surface temperature of the second cooling roll 13 was 60° C., and the forming speed was 1.1 m / min. Next, the obtained raw film was hung in a hot air circulating thermostatic chamber set at the temperature shown in Table 1, and heat-treated for 18 hours to obtain a film. The surface temperature T1 of the extrudate when it comes into contact with the first cooling roll 12, the surface temperature T of the first cooling roll r1 The physical properties (density, water vapor transmission rate, haze, tensile elongation) of the obtained film are shown in Table 1.

[0088] (Example 5) A film was obtained in the same manner as in Example 1, except that the raw film was not subjected to heat treatment. The physical properties of the film are shown in Table 1. The physical properties of the film of Example 5 can be considered to be the physical properties of the original film of Examples 1-4.

[0089] (Example 6) A film was obtained in the same manner as in Example 5, except that the surface temperature of the first cooling roll 12 was set to 148° C. The physical properties of the film are shown in Table 1.

[0090] [Table 1]

[0091] From the results in Table 1, the following was confirmed: When the extrudate is brought into contact with a first cooling roll having a surface temperature of 120° C. or less while the surface temperature T1 of the extrudate is higher than the crystallization temperature of PCTFE, a raw film having low haze and high tensile elongation is obtained. This raw film has low haze and high tensile elongation, and therefore low crystallinity. When this raw film is heat-treated at 80 to 200° C., the density increases and the WVTR and haze decrease while maintaining sufficient tensile elongation. [Industrial Applicability]

[0092] There is no particular limitation on the applications of the film of the present invention and the laminate of the present invention, and they can be used, for example, as packaging materials, surface materials for flexible solar cells, surface materials for display elements using organic electroluminescence, and the like. Since the film of the present invention is excellent in water vapor barrier properties, transparency and tensile elongation, the film of the present invention and the laminate of the present invention are preferably used as packaging materials. The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2018-157183, filed on August 24, 2018, are hereby incorporated by reference as the disclosure of the specification of the present invention. [Explanation of symbols]

[0093] REFERENCE SIGNS LIST 1 extrusion product, 2 film roll, 3 film, 10 film roll manufacturing device, 11 extrusion die, 12 first cooling roll, 13 second cooling roll, 14 nip roll, 20 heat treatment device, 21 winding roll, 22 thermostatic chamber, 23 hanging tool, 30 heat treatment device, 31 unwinding roll, 32 heat treatment section, 33 conveying roll, 34 winding roll, 40 laminate, 41 layer made of the film of the present invention, 43 base layer, 45 adhesive layer, 50 package, 51 container, 51a pocket portion, 53 lid material, 60 contents< / wvtr> < / mvr>

Claims

1. Contains polychlorotrifluoroethylene, Water vapor permeability of 0.02 to 0.06 g / (m2) at 37.8°C and 100% relative humidity per 100 μm thickness ２ ・Days) or less, The haze per 100 μm thickness is 3% or less, The tensile elongation at 23°C in each of the MD and TD is 30% or more and 350% or less, Density is 2.125 g / cm ３ That's it, film.

2. A laminate comprising a layer of the film of claim 1 and one or more other layers.

3. A packaging material comprising the film of claim 1 or the laminate of claim 2.

4. The packaging material according to claim 3, which is for blister packaging.

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