JP5705064B2 - Laminated body and container containing polyvinylidene chloride biaxially stretched film - Google Patents

Description

  The present invention relates to a polyvinylidene chloride biaxially stretched film, a laminate thereof, and a container.

  Currently, polyvinylidene chloride-based films have excellent gas barrier properties against gases such as oxygen, water vapor, and carbon dioxide, so they can be used as packaging for food, industrial products, pharmaceuticals, etc. as single-layer films, co-pressed films, or laminating films. Is used. Among them, one type of packaging is drawn packaging. This is a method in which a soft film or a hard sheet is heated and then molded into a container shape by a method such as vacuum compression or plug assist, and then the contents are filled, and a package is formed with a top seal or the like.

  Patent Document 1 discloses a technology relating to a polyester film for automobile interior materials that controls the degree of crystal orientation of the film in order to make it difficult to cut the film during drawing. Patent Document 2 discloses a technique related to a polyvinylidene chloride-based unstretched co-pressed film for molding applications.

JP 2007-030358 A JP 59-049970 A

  When a polyvinylidene chloride film is used for drawing packaging, the biaxially stretched film has poor moldability, and the unstretched film has low impact strength because the crystals in the film are not oriented. Even if it is good, there is a problem that it is inferior in impact strength.

  The film described in Patent Document 1 is made of polyester, and there is no disclosure about using polyvinylidene chloride. Since the film described in Patent Document 2 is an unstretched film, the polyvinylidene chloride layer in the film is vulnerable to impact, and when the package after filling the contents is dropped, the polyvinylidene chloride layer There were problems such as cracks.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a polyvinylidene chloride biaxially stretched film excellent in moldability and impact strength.

  As a result of diligent studies to solve the above problems, the present inventors have controlled the degree of crystal orientation and tensile elongation at break to a specific range, thereby making it possible to obtain a polyvinylidene chloride-based polymer having excellent moldability and impact strength. It discovered that an axial stretched film was obtained and came to complete this invention.

That is, the present invention is as follows.
[1]
From the full width at half maximum μ (°) of the peak that appears when the diffraction peak intensity of the (100) plane measured by transmission two-dimensional wide-angle X-ray scattering measurement from the edge direction of the film is plotted against the azimuth, it is defined by the following formula 1. The crystal orientation degree F is 70% to 89.5%, and
The tensile elongation at break at 23 ° C. in the MD direction and TD direction is both 80% or more.
Polyvinylidene chloride biaxially stretched film.

(Formula 1) F = 100 × (180−μ) / 180

[2]
The polyvinylidene chloride biaxially stretched film is a film containing a copolymer consisting of 90 to 98% by mass of vinylidene chloride and 10 to 2% by mass of methyl acrylate,
The polyvinylidene chloride biaxially stretched film according to [1], wherein the polyvinylidene chloride biaxially stretched film has a weight average molecular weight of 60,000 to 130,000.
[3]
[1] or [2] polyvinylidene chloride biaxially stretched film,
A film containing at least one selected from the group consisting of polyolefin, polyvinyl chloride, polyamide, polyester, cyclic olefin copolymer, cyclic polyolefin, fluororesin, and polystyrene, laminated on the polyvinylidene chloride biaxially stretched film; ,
A laminate comprising
[4]
[3] The laminate according to [3], wherein the shrinkage at 120 ° C. in the MD direction and the TD direction are both 7% or less.
[5]
A container comprising the laminate according to [3] or [4].

  ADVANTAGE OF THE INVENTION According to this invention, the polyvinylidene chloride biaxially stretched film excellent in the moldability and impact resistance can be provided.

It is a conceptual diagram which shows an example of the apparatus which extrude-forms the polyvinylidene chloride biaxially stretched film of this embodiment. It is the schematic which shows an example of the heat processing apparatus for adjusting the crystal orientation in the polyvinylidene chloride biaxially stretched film of this embodiment.

  Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as “the present embodiment”) will be described in detail. The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be implemented with appropriate modifications within the scope of the gist thereof. In each drawing, unless otherwise specified, the positional relationship such as up, down, left, and right is based on the positional relationship shown in the drawings, and the dimensional ratios in the drawings are not limited to the illustrated ratios. Furthermore, in the present specification, the term “abbreviated” indicates the meaning of the term excluding the “abbreviation” within the scope of technical common knowledge of those skilled in the art, Shall also be included.

The film of the present embodiment is obtained from the full width at half maximum μ (°) of the peak that appears when the diffraction peak intensity of the (100) plane by transmission two-dimensional wide-angle X-ray scattering measurement from the edge direction is plotted against the azimuth. The degree of crystal orientation F defined by Formula 1 is 70% to 89.5%, and the tensile elongation at break at 23 ° C. in the MD direction and the TD direction is both 80% or more. An axially stretched film (hereinafter sometimes simply referred to as “film”). In this embodiment, unless otherwise specified, the “film” includes a form called a “sheet”.

(Formula 1) F = 100 × (180−μ) / 180

  The degree of crystal orientation F of the film of this embodiment is 70% to 89.5%, preferably 80% to 88%. If the degree of crystal orientation F is 70% or more, the impact strength is sufficient, and even if the molded container is filled with the contents and subjected to a drop-off test, the film is hardly cracked and should be 80% or more. In this case, cracks are less likely to occur. If the crystal orientation degree F is 89.5% or less, the moldability is good, and if it is 88% or less, the moldability becomes better. The crystal orientation degree F can be controlled by controlling heat treatment conditions such as a heat treatment temperature described later.

  The lower limit values of the tensile breaking elongation at 23 ° C. in the MD direction and the TD direction of the film of this embodiment are both 80% or more, and preferably 100% or more. If it is 80% or more, the moldability is good, and if it is 100% or more, the moldability becomes better. Here, the MD direction is the film flow direction, and the TD direction is the direction perpendicular to the flow direction. The tensile elongation at break can be measured according to ASTM D-882. The tensile elongation at break can be controlled by controlling the heat treatment conditions after film formation described later.

  The polyvinylidene chloride resin composition used for the film of this embodiment may be a homopolymer of a vinylidene chloride monomer, or a copolymer of a vinylidene chloride monomer and a monomer copolymerizable therewith. It may be a polymer. The polyvinylidene chloride resin composition may include one type of polyvinylidene chloride resin, or may include two or more types of polyvinylidene chloride resin. The monomer copolymerizable with the vinylidene chloride monomer is not particularly limited, and vinyl chloride, acrylic acid esters such as methyl acrylate and butyl acrylate, and methacrylate esters such as methyl methacrylate and butyl methacrylate. , Acrylonitrile, vinyl acetate and the like. Among these, methyl acrylate is preferable from the balance between the gas barrier property of the film and the extrusion processability. These monomers capable of copolymerization may be used alone or in combination of two or more.

  The polyvinylidene chloride resin composition of the present embodiment preferably includes a copolymer composed of a vinylidene chloride monomer and a methyl acrylate monomer. In this case, it is more preferable that the copolymer is 90 to 98% by mass of vinylidene chloride and 10 to 2% by mass of methyl acrylate. When the content of methyl acrylate is 2% by mass or more, the melting characteristics during extrusion film formation are better. Moreover, if content of methyl acrylate is 10 mass% or less, higher gas barrier performance can be generated.

  When the polyvinylidene chloride resin composition of the present embodiment includes a copolymer composed of the above-mentioned vinylidene chloride monomer and methyl acrylate monomer, gel permeation chromatography (GPC) of the copolymer is included. It is desirable that the weight average molecular weight (Mw) with polystyrene as a standard determined in (Method) is 60,000 to 130,000. If Mw is 60,000 or more, the strength that can withstand film-forming stretching is further improved, and if it is 130,000 or less, melt extrusion can be performed more efficiently.

  In the case of vinylidene chloride-vinyl chloride copolymer, the weight average molecular weight (Mw) based on polystyrene determined by gel permeation chromatography (GPC method) of the copolymer is 60,000 to 130,000. It is preferable that If Mw is 60,000 or more, the strength that can withstand film-forming stretching is further improved, and if it is 130,000 or less, melt extrusion can be performed more efficiently.

  Additives such as a plasticizer and a heat stabilizer can be blended with the polyvinylidene chloride resin composition. It does not specifically limit as a plasticizer, A well-known thing can be used. Examples thereof include acetyl tributyl citrate, acetylated monoglyceride, dibutyl sebacate and the like. It does not specifically limit as a heat stabilizer, A well-known thing can be used. Examples thereof include epoxidized vegetable oils such as epoxidized soybean oil and epoxidized linseed oil, and epoxy resins. In addition, additives such as known colorants, organic lubricants, inorganic lubricants, surfactants and the like can be added within the scope of the effect of the present embodiment.

  The film stretching method of the present embodiment is not particularly limited, and a commonly used stretching method can be employed. For example, a tenter method or a double bubble method can be employed.

  As an example of the film manufacturing method of this embodiment, the conceptual diagram which shows an example of the apparatus which extrude-forms the biaxially stretched polyvinylidene chloride film of this embodiment in FIG. 1 is shown. In FIG. 1, a vinylidene chloride resin composition supplied from a hopper 102 of an extruder 101 is propelled by a screw 103, heated and kneaded, melted, and extruded from a slit portion of an annular die 104 attached to the tip of the extruder. As a result, a cylindrical parison 105 is formed. The cylindrical parison 105 is cooled by the cold water in the cooling tank 106, led to the pinch rolls A and A ′, preheated in the hot water tank 107, and is in the cylindrical film between the pinch rolls B, B ′, C and C ′. The tube is stretched in the circumferential direction and longitudinal direction of the cylinder according to the volume of air sealed in and the speed ratio between the pinch rolls B, B ′, C, and C ′. The stretched tubular film is folded into a flat two-layer stack, and after being heat-treated at 70 ° C. by the heat set roll 108, it is wound by the take-up roll 109.

  FIG. 2 is a conceptual diagram showing an example of a heat treatment apparatus for adjusting the degree of crystal orientation in the polyvinylidene chloride biaxially stretched film of the present embodiment. The film is sent from the feeding unit 201 to the drying furnace 203 and heat-treated, and then sent to the winding unit 203 to be wound up. In the drying furnace 203, it is preferable to adjust the degree of crystal orientation by changing the heat treatment time at a drying temperature of 75 ° C to 80 ° C. If the temperature is 80 ° C. or lower, film shrinkage can be effectively suppressed during the heat treatment, and if it is 75 ° C. or higher, the heat treatment time for adjusting the degree of crystal orientation can be shortened.

  About the heat processing time in the case of the drying temperature of 75 to 80 degreeC, for example, when the heat processing temperature is 80 degreeC, it is preferable that it is 2 to 4 minutes. If it is 2 minutes or more, the degree of crystal orientation can be increased, and the impact strength of the molded container tends to be increased. If it is 4 minutes or less, it can suppress that a crystal orientation degree becomes large too much and the moldability of a film deteriorates.

  The tensile elongation at break can also be adjusted by heat treatment. The heat treatment time is preferably 4 minutes or less at 80 ° C. By setting the heat treatment condition at 80 ° C. for 4 minutes or less, a tensile elongation at break of 80% or more can be efficiently realized.

  The polyvinylidene chloride biaxially stretched film of the present embodiment can be laminated with other films or foams to form a laminate. As other film and foam materials, polyolefin, polyvinyl chloride, polyamide, polyester, cyclic olefin copolymer, cyclic polyolefin, fluororesin, polystyrene, and the like are preferable.

  Specifically, the polyolefin, polyvinyl chloride, polyamide, polyester, cyclic olefin copolymer, cyclic polyolefin laminated on the polyvinylidene chloride biaxially stretched film of the present embodiment and the polyvinylidene chloride biaxially stretched film. And a laminate including at least one film selected from the group consisting of a fluororesin and polystyrene. A laminate having such a structure is preferable because it can exhibit strength that can be withstood as a packaging material. In addition, a foam etc. can also be used as the said film used for a laminated body. Examples of preferable materials for the foam include polystyrene, polyethylene, and polypropylene.

  In the present embodiment, the laminated structure of the laminated body is not particularly limited, and may be either a symmetric structure or an asymmetric structure. Moreover, it can be set as the laminated body of the multilayer structure which consists of two layers, three layers, or more layers. The thickness of the laminate of this embodiment is preferably 50 μm to 3000 μm.

  The production method of the laminate is not particularly limited, and a coextrusion method, an extrusion lamination method, a dry lamination method, a thermal lamination method, or the like can be used. An example of each method is shown below.

  Examples of the coextrusion method include a method in which each resin is melted with several types of extruders and laminated through a multilayer die. At that time, an adhesive resin exists between the polyvinylidene chloride-based resin layer and the other resin layers. Examples of the adhesive resin include ethylene-vinyl acetate resin, acid-modified polyolefin resin, urethane resin layer, and the like.

  As an extrusion laminating method, for example, an anchor coating agent is applied to a polyvinylidene chloride film after biaxial stretching and dried, and then a polyethylene resin is laminated while being extruded from a T die, and immediately after that, a nip is formed by a cooling roll. The method of laminating is mentioned.

  Examples of the dry laminating method include a method in which an adhesive is applied to the film and dried, and then laminated with a polyvinylidene chloride film.

  As the thermal laminating method, for example, an unstretched polypropylene sheet is laminated on a film in which unstretched polypropylene is laminated on both sides of a biaxially stretched polyvinylidene chloride film by a dry laminating method, and immediately after that, pressure is applied by a hot roll. The method of adhering while applying is mentioned.

  In the laminate of the present embodiment, the shrinkage at 120 ° C. in the MD direction and the TD direction is preferably 7% or less, more preferably 0 to 5%, and more preferably 0 to 3%. Is more preferable. If the shrinkage ratio in the MD direction and the TD direction is both 7% or less, excessive shrinkage of the laminate during heat molding can be effectively prevented, so that generation of wrinkles can be effectively suppressed and molding is performed. The property becomes even better. The shrinkage rate at 120 ° C. in the MD direction and the TD direction can be obtained from dimensional changes before and after heat treatment by leaving the film in an oven at 120 ° C. for 5 minutes in an unconstrained state.

  Various containers can be formed by molding the laminate of the present embodiment. As a method for producing the container, a known method such as a vacuum / pressure forming method or a plug assist forming method can be used.

  An example of the vacuum / pressure forming machine is an FFS machine. An example of a molding method using an FFS machine will be described. First, after the film for molding is drawn out, the sheet is heated by a hot plate, and after the sheet is molded into a predetermined shape by vacuum and compressed air, the content is filled. On the other hand, the drawn out film for the lid is top-sealed with the molding film filled with the contents. Thereafter, it is continuously slit to form the final individual package. Since the molded container of this embodiment is excellent in gas barrier properties, moldability and impact strength, it is suitable for containers for foods, industrial products and pharmaceuticals.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited at all by these.

1. Crystal orientation F
The degree of crystal orientation F of the polyvinylidene chloride biaxially stretched film was calculated from Equation 1 using the full width at half maximum μ (°) measured according to the following method. (unit:%)

(Formula 1) F = 100 × (180−μ) / 180

  The method for measuring the full width at half maximum μ is shown below. The full width at half maximum μ is obtained by measuring an edge image obtained when transmission two-dimensional wide-angle X-ray scattering (WAXS) is measured, that is, when X-rays are incident in parallel to the film surface from the side surface of the film. After plotting the primary reflection peak intensity of the two-dimensional scattering pattern (Edge View Pattern) against the azimuth angle, the peak intensity and background level of the obtained peak are obtained, and the intensity is (peak intensity−background) / 2 + The peak width at the background position was used. Specifically, when the molecular chain direction of the polyvinylidene chloride resin composition crystal is oriented in a certain principal axis direction, a diffraction peak of (100) plane appears in the perpendicular direction (90 °) of the azimuth angle. The full width at half maximum μ (°) was determined from the dependency of the peak intensity on the azimuth angle. When calculating the azimuth angle dependence of the diffraction peak intensity of the (100) plane from the obtained two-dimensional scattering peak, the diffraction peak intensity is 14.8 ° <2θ <16.3 ° (2θ: scattering angle). Accumulated over the range.

  The measurement is performed using an X-ray structure evaluation apparatus (“NanoViewer” manufactured by Rigaku Corporation) and collimated using a 0.4 mm diameter first slit and a 0.3 mm diameter second slit at a wavelength of 0.154 nm. And using an imaging plate (“BAS-IP SR127” manufactured by Fuji Film Co., Ltd.) as a detector. In order to prevent scattering from the air, a vacuum was formed between the second slit and the subsequent detector. The obtained scattering was subjected to empty cell scattering correction. The resolution (size) of one pixel was 50 μm × 50 μm. In order to allow X-rays to enter from the side of the film (edge direction), a sample film with a thickness of 1 mm is prepared by stacking, and by cutting this from the film normal direction, a sample with a width of 0.1 mm is cut out and measured It was used for. When the films were stacked, the films were bonded with a minimum amount of an epoxy adhesive (“High Super 5” manufactured by Cemedine Co., Ltd.) that does not affect scattering.

2. Tensile elongation at break was measured according to ASTM D-882. The measurement was performed in an atmosphere of 23 ° C. and 50% RH. Using a tensile measuring machine ("TENSILON RTC-1210", manufactured by ORIENTEC), the tensile elongation at break in the MD and TD directions was measured. The width of the sample film is 10 mm, the distance between chucks is 50 mm, and the tensile speed is 50 mm / min.

3. Oxygen transmission rate (OTR)
Measured according to ASTM D-3985. The measurement was performed in an atmosphere of 23 ° C. and 65% RH using a sample film having a thickness of 25 μm as a sample and using an oxygen transmission rate measuring device “Mocon OX-TRAN 2/20”.

4). Laminate Structure In Examples and Comparative Examples described later, a laminate using a film other than a polypropylene film (PP film, Example 4: thickness 600 μm) and a foamed styrene film (PSP film, Example 8: thickness 2000 μm) will be described later. This was performed by a dry laminating method using a urethane two-component adhesive. Lamination using at least one of PP film and PSP film was performed by a thermal laminating method in which the film was pressure-bonded with a heating roll.

5. Shrinkage rate of film after lamination The film was left in an oven at 120 ° C. for 5 minutes in an unrestrained state, and the shrinkage rate was determined from the dimensional change before and after heat treatment in the MD direction and TD direction of the laminate film.

6). Formability of polyvinylidene chloride single-layer film Vacuum and pressure molding was performed with a single molding machine ("FVS-500") manufactured by Wakisaka Engineering Co., Ltd. All were molded using a 100 mm square square mold with a 45 mm depth and a 50 mm mold. The molding temperature was adjusted so that the film temperature was 120 ° C. And the moldability was evaluated based on the following criteria.
Evaluation result (double-circle): It was able to shape | mold without the fracture | rupture of a film in any of depth 45mm and 50mm.
○: The film could be formed without breaking the film at a depth of 45 mm, but the film was broken at a depth of 50 mm.
X: The film broke at both the depth of 45 mm and 50 mm.

7). Impact Strength of Polyvinylidene Chloride Single Layer Film Measurement was performed according to ASTM-D3420. A polyvinylidene chloride monolayer film was cut into a size of 100 mm × 100 mm, and measurement was performed using a measuring device film impact tester (manufactured by Tester Sangyo Co., Ltd.) at an ambient temperature of 23 ° C. And impact strength was evaluated based on the following criteria.
Evaluation result ◎: 1.2J or more ○: 0.6 to 1.2J
×: Less than 0.6J

8). Formability of laminated film Vacuum / pressure forming was performed except for Example 4 and Example 8 on a single-shot molding machine ("FVS-500") manufactured by Wakisaka Engineering Co., Ltd. About Example 4 and Example 8, it shape | molded by the plug assist method with the same single molding machine. All were molded using a 100 mm square square with a 45 mm depth and a 50 mm mold. The molding temperature was adjusted so that the film temperature was 120 ° C. And the moldability was evaluated based on the following criteria.
Evaluation result (double-circle): It was able to shape | mold without the fracture | rupture of a film in any of depth 45mm and 50mm.
○: The film could be formed without breaking the film at a depth of 45 mm, but the film was broken at a depth of 50 mm.
X: The film broke at both the depth of 45 mm and 50 mm.

9. Impact strength of laminated film Of the examples and comparative examples to be described later, a molded container having a depth of 45 mm was prepared using the laminated film obtained above, and the molded container was filled with 350 cc of water. Then, a deaeration seal was performed using a lid material.
For Examples 1, 2, 3, 4, 6, 7, and 9 and Comparative Examples 1 and 2, as a cover material, a biaxially stretched nylon film (ONy film, manufactured by Unitika Ltd., trade name “Emblem”) 15 μm // Polyvinylidene chloride film (product name “Saran UB” manufactured by Asahi Kasei Chemicals Co., Ltd.) 15 μm // unstretched polypropylene film (CPP film, product manufactured by Toray Film Processing Co., Ltd., product name “Trephan ZK93KM”) 50 μm dry laminate film used did.
About Example 5, as a cover material, ONy film (15 μm) // Saran UB (15 μm) // Unstretched linear low density polyethylene film (LL film: manufactured by Tosero Co., Ltd., trade name “HZR-2”) 60 μm The dry laminate film was used.
In Example 8, a dry laminate film having an ONy film of 15 μm // Saran UB (15 μm) // unstretched polystyrene film (CPS film: manufactured by Towa Chemical Industry Co., Ltd., trade name “Stylon”) was used as a cover material.
Hereinafter, unless otherwise specified, “//” means an adhesive layer.

And it was dropped once each from the height of 0.7 m and 1 m in 23 degreeC atmosphere. Thereafter, the molded container was disassembled, and whether or not there was a crack in the PVDC layer of the molded container was observed with a microscope. And impact strength was evaluated based on the following criteria.
Evaluation result (double-circle): There was no crack in a PVDC layer in any case of the height of 0.7 m and 1 m.
○: There was no crack in the PVDC layer when dropped from a height of 0.7 m, and a crack occurred in the PVDC layer when dropped from a height of 1 m.
X: Cracks occurred in the PVDC layer in both cases of 0.7 m and 1 m.

[Example 1]
According to the description in JP-A-2008-074908, a vinylidene chloride (VDC) / vinyl chloride (VC) = 90/10 (weight ratio) copolymer having a weight average molecular weight of 120,000 was synthesized. On the other hand, a polyvinylidene chloride resin composition in which 2 wt% of epoxidized soybean oil (trade name “Newsizer 510”, manufactured by NOF Corporation) as a heat stabilizer and 4 wt% of dibutyl sebacate as a plasticizer are mixed ( PVDC) was formed using the apparatus shown in FIG. 1 to obtain a single-layer film 1 having a thickness of 25 μm. The draw ratio at this time was MD / TD = 2.5 times / 2.5 times.
Next, heat treatment was performed at a preset temperature of 80 ° C. for 3 minutes using the apparatus shown in FIG. Moreover, this film was laminated | stacked with the other film by the dry lamination method (dry lamination conditions etc. are shown below). Single-layer film 1 (PVDC layer; 25 μm thickness) as a core material, unstretched nylon 6 film (CNy film; 25 μm thickness: manufactured by Toray Film Processing Co., Ltd., trade name “Rayfan NO1401”) and unstretched polypropylene film (CPP film) ; 50 μm thickness: Toray Film Processing Co., Ltd., trade name “Trephan 3301”) was laminated. The obtained laminate film was aged at 40 ° C. for 4 days to cure the adhesive, and a laminated film 1 having a CPP of 50 μm // PVDC 25 μm // CNy 25 μm was obtained.

(Dry laminating conditions etc.)
Pull-out speed: 100m / min
Unwinding film tension: 7 kg / m width Winding film tension: 10 kg / m width Nip roll: 60 ° C.
Drying; 70 ° C. × 20 seconds Coating method; Gravure coat Adhesive; Urethane-based two-component type (Mitsui Chemicals, trade name “A520” and trade name “A50” mixed at a ratio of 10: 1 ) Was dissolved in ethyl acetate having a weight three times the amount of the adhesive as a solvent.
Application amount: 4 g / m ² · day (dry)

[Example 2]
In the same manner as in Example 1, a copolymer of vinylidene chloride (VDC) / methyl acrylate (MA) = 99/1 (weight ratio) having a weight average molecular weight of 100,000 was synthesized. A polyvinylidene chloride resin composition (PVDC) mixed with 2 wt% of epoxidized soybean oil as a heat stabilizer was formed into a film with the apparatus shown in FIG. 1 to obtain a single-layer film 2 having a thickness of 25 μm. The draw ratio at this time was MD / TD = 2.5 times / 2.5 times.
Next, heat treatment was performed at a preset temperature of 80 ° C. for 3.6 minutes using the apparatus shown in FIG. And it carried out similarly to Example 1, and obtained the laminated film 2 of CPP film 50micrometer // single layer film 2 (PVDC) 25micrometer // CNy film 25micrometer by the dry lamination method.

[Example 3]
In the same manner as in Example 1, a copolymer of vinylidene chloride (VDC) / methyl acrylate (MA) = 91/9 (weight ratio) having a weight average molecular weight of 100,000 was synthesized. A polyvinylidene chloride resin composition (PVDC) mixed with 2 wt% of epoxidized soybean oil as a heat stabilizer was formed into a film with the apparatus shown in FIG. 1 to obtain a single-layer film 3 having a thickness of 25 μm. The draw ratio at this time was MD / TD = 3.0 times / 3.1 times. Next, heat treatment was performed at a set temperature of 80 ° C. for 2 minutes using the apparatus shown in FIG. And it carried out similarly to Example 1, and obtained the laminated | multilayer film 3 of CPP film 50micrometer // single layer film 3 (PVDC) 25micrometer // CNy film 25micrometer by the dry laminating method.

[Example 4]
In the same manner as in Example 1, a copolymer of vinylidene chloride (VDC) / methyl acrylate (MA) = 92/8 (weight ratio) having a weight average molecular weight of 70,000 was synthesized. A polyvinylidene chloride resin composition (PVDC) mixed with 2 wt% of epoxidized soybean oil as a heat stabilizer was formed into a film with the apparatus shown in FIG. 1 to obtain a single-layer film 4 having a thickness of 25 μm. The draw ratio at this time was MD / TD = 3.0 times / 2.9 times.
Next, heat treatment was performed at a preset temperature of 80 ° C. for 2.5 minutes using the apparatus shown in FIG. In the same manner as in Example 1, after obtaining a laminated film 4 of CPP film 50 μm // single layer film 4 (PVDC) 25 μm // CPP film 20 μm by dry laminating method, this laminated film and polypropylene film 600 μm (PP Film, manufactured by Sekisui Molding Industry Co., Ltd., trade name “P-2127”) was adhered by a thermal lamination method. The nip roll temperature during thermal lamination is 150 ° C. In this way, a laminated film 4 having a CPP of 50 μm // PVDC 25 μm // CPP 20 μm // PP 600 μm was obtained.

[Example 5]
In the same manner as in Example 1, a copolymer of vinylidene chloride (VDC) / methyl acrylate (MA) = 95/5 (weight ratio) having a weight average molecular weight of 75,000 was synthesized. A polyvinylidene chloride resin composition (PVDC) mixed with 2 wt% of epoxidized soybean oil as a heat stabilizer was formed into a film with the apparatus of FIG. 1 to obtain a single-layer film 5 having a thickness of 25 μm. The draw ratio at this time was MD / TD = 2.7 times / 2.7 times.
Next, heat treatment was performed at a preset temperature of 80 ° C. for 2.8 minutes using the apparatus shown in FIG. Then, in the same manner as in Example 1, an unstretched linear low-density polyethylene film (LL film: manufactured by Tosero Co., Ltd., trade name “HZR-2”) 60 μm // single layer film 5 (PVDC) 25 μm by the dry laminating method. // The laminated film 5 of CNy film 25 micrometers was obtained.

[Example 6]
In the same manner as in Example 1, a copolymer of vinylidene chloride (VDC) / methyl acrylate (MA) = 93/7 (weight ratio) having a weight average molecular weight of 76,000 was synthesized. A polyvinylidene chloride resin composition (PVDC) mixed with 2 wt% of epoxidized soybean oil as a heat stabilizer was formed into a film with the apparatus shown in FIG. 1 to obtain a single-layer film 6 having a thickness of 25 μm. The draw ratio at this time was MD / TD = 2.9 times / 2.8 times.
Next, heat treatment was performed at a preset temperature of 80 ° C. for 2.8 minutes using the apparatus shown in FIG. And the laminated film 6 of CPP film 50micrometer // single layer film 6 (PVDC) 25micrometer // CNy film 25micrometer was obtained by the dry-laminating method like Example 1. FIG.

[Example 7]
In the same manner as in Example 1, a copolymer of vinylidene chloride (VDC) / methyl acrylate (MA) = 96/4 (weight ratio) having a weight average molecular weight of 80,000 was synthesized. A polyvinylidene chloride resin composition (PVDC) mixed with 2 wt% of epoxidized soybean oil as a heat stabilizer was formed into a film with the apparatus shown in FIG. 1 to obtain a single-layer film 7 having a thickness of 25 μm. The draw ratio at this time was MD / TD = 2.6 times / 2.6 times.
Next, heat treatment was performed at a preset temperature of 80 ° C. for 3 minutes using the apparatus shown in FIG. Then, in the same manner as in Example 1, CPP film 50 μm // single-layer film 3 (PVDC) 25 μm // polyvinyl chloride film (PVC film, manufactured by Nagaka Kogyo Co., Ltd., trade name “C-MSF-” N—F ”), a 200 μm laminated film 7 was obtained.

[Example 8]
In the same manner as in Example 1, a copolymer of vinylidene chloride (VDC) / methyl acrylate (MA) = 98/2 (weight ratio) having a weight average molecular weight of 90,000 was synthesized. A polyvinylidene chloride resin composition (PVDC) mixed with 2 wt% of epoxidized soybean oil as a heat stabilizer was formed into a film with the apparatus shown in FIG. 1 to obtain a single-layer film 8 having a thickness of 25 μm. The draw ratio at this time was MD / TD = 2.6 times / 2.5 times.
Next, heat treatment was performed for 3.4 minutes at a set temperature of 80 ° C. using the apparatus shown in FIG. Then, in the same manner as in Example 1, a biaxially stretched polystyrene film (OPS film, manufactured by Asahi Kasei Chemicals Corporation, trade name “GM”) 14 μm // single layer film 8 (PVDC) 25 μm // OPS film 14 μm by the dry laminating method. A laminated film was obtained. Later, the laminated film 8 was bonded to a foamed styrene film (PSP film, thickness 2000 μm, manufactured by JSP) by a thermal lamination method.

[Comparative Example 1]
In the same manner as in Example 1, a vinylidene chloride (VDC) / methyl acrylate (MA) = 94/6 (weight ratio) copolymer having a weight average molecular weight of 100,000 was synthesized. A polyvinylidene chloride resin composition (PVDC) mixed with 2 wt% of epoxidized soybean oil as a heat stabilizer was formed into a film with the apparatus shown in FIG. 1 to obtain a single-layer film a having a thickness of 25 μm. The draw ratio at this time was adjusted to MD / TD = 2.0 times / 2.0 times. This film was not heat-treated with the apparatus of FIG. Then, in the same manner as in Example 1, a laminated film a of CPP film 50 μm // single layer film a (PVDC) 25 μm // CNy film 25 μm was obtained by a dry laminating method.

[Comparative Example 2]
In the same manner as in Example 1, a vinylidene chloride (VDC) / methyl acrylate (MA) = 94/6 (weight ratio) copolymer having a weight average molecular weight of 100,000 was synthesized. A polyvinylidene chloride resin composition (PVDC) mixed with 2 wt% of epoxidized soybean oil as a heat stabilizer was formed into a film with the apparatus shown in FIG. 1 to obtain a single-layer film b having a thickness of 25 μm. The draw ratio at this time was MD / TD = 2.8 times / 2.7 times.
Next, heat treatment was performed at 80 ° C. for 5 minutes using the apparatus of FIG. And the laminated film b of CPP film 50micrometer // single layer film b (PVDC) 25micrometer // CNy film 25micrometer was obtained by the dry laminating method like Example 1. FIG. In addition, since the fracture | rupture generate | occur | produced in shaping | molding of the laminated | multilayer film b, the drop test for impact strength evaluation was not able to be implemented.

[Example 9]
In the same manner as in Example 1, a vinylidene chloride (VDC) / methyl acrylate (MA) = 94/6 (weight ratio) copolymer having a weight average molecular weight of 100,000 was synthesized. A polyvinylidene chloride resin composition (PVDC) mixed with 2 wt% of epoxidized soybean oil as a heat stabilizer was formed into a film with a thickness of 25 μm using the apparatus shown in FIG. The draw ratio at this time was MD / TD = 2.8 times / 2.7 times.
Next, heat treatment was performed at a set temperature of 80 ° C. for 3.2 minutes using the apparatus shown in FIG. Then, a laminate film 9 of CPP film 50 μm // single layer film 9 (PVDC) 25 μm // CNy film 25 μm was used in the same manner as in Example 1 except that the feeding film tension was changed to 15 kg / m width when dry laminating. Got. Although some wrinkles due to heat shrinkage occurred during molding of the laminated film 9 after lamination, it was at a level causing no practical problems.

  Table 1 shows the results of each example and each comparative example.

  As shown in Table 1, it was confirmed that the moldability and impact strength of the single layer film and the laminated film were excellent in each example. On the other hand, in the comparative example, it was confirmed that at least one of the moldability and impact strength of the single layer film was bad and at least one of the moldability and impact strength of the laminated film was bad.

  The polyvinylidene chloride biaxially stretched film of the present invention is excellent in moldability, and the molded container is excellent in impact resistance. Therefore, it is used for a wide range of applications such as containers for storing various foods, industrial products, pharmaceuticals, etc. be able to.

DESCRIPTION OF SYMBOLS 101 ... Extruder, 102 ... Hopper part, 103 ... Screw, 104 ... Ring die, 105 ... Cylindrical parison, 106 ... Cooling tank, 107 ... Hot water tank, 108 ... Heat set roll, 109 ... Winding roll, A, A ', B, B', C, C '... Pinch roll, 201 ... Feeding part, 202 ... Drying furnace, 203 ... Rewinder

Claims (4)

From the full width at half maximum μ (°) of the peak that appears when the diffraction peak intensity of the (100) plane measured by transmission two-dimensional wide-angle X-ray scattering measurement from the edge direction of the film is plotted against the azimuth, it is defined by the following formula 1. The crystal orientation degree F is 70% to 89.5%, and
The tensile elongation at break at 23 ° C. in the MD direction and TD direction is both 80% or more.
A polyvinylidene chloride biaxially stretched film ;
A film containing at least one selected from the group consisting of polyolefin, polyvinyl chloride, polyamide, polyester, cyclic olefin copolymer, cyclic polyolefin, fluororesin, and polystyrene, laminated on the polyvinylidene chloride biaxially stretched film; ;
A laminate comprising

(Formula 1) F = 100 × (180−μ) / 180 The polyvinylidene chloride biaxially stretched film is a film containing a copolymer consisting of 90 to 98% by mass of vinylidene chloride and 10 to 2% by mass of methyl acrylate,
The laminate according to claim 1, wherein the polyvinylidene chloride biaxially stretched film has a weight average molecular weight of 60,000 to 130,000. The laminate according to claim 1 or 2 , wherein both of the shrinkage rates at 120 ° C in the MD direction and the TD direction are 7% or less. The container containing the laminated body as described in any one of Claims 1-3 .