Method for producing film, wound body, and film

Abstract

This method for producing a film uses part of a printed film as a raw material. The printed film includes: a product part on which a first design is printed; and an ear part provided at a position adjacent to at least one of both ends of the product part in the width direction of the printed film. The method for producing a film involves: a step for cutting out the ear part from the printed film; a step for collecting the ear part cut out from the printed film; a step for producing a resin raw material by using the collected ear part; and a step for producing a film by using the resin raw material.

Description

Film manufacturing method, roll and film

[0001] The present invention relates to a method for producing a film, a roll, and a film.

[0002] Japanese Patent No. 6849141 (Patent Document 1) discloses a method for producing a heat-shrinkable film, in which a packaging material is used as a starting material (see Patent Document 1).

[0003] Patent No. 6849141

[0004] In the method for producing a heat-shrinkable film disclosed in Patent Document 1, when the packaging material has a printed layer, an ink peeling treatment is performed. However, the ink peeling treatment requires a great deal of cost, which results in an increase in the price of the produced film.

[0005] The present invention has been made to solve such problems, and its purpose is to provide a film manufacturing method that can produce relatively high-quality film when printed film is used as a raw material and the ink on the printed film is not removed, a roll used in the manufacturing method, and a film manufactured by the manufacturing method.

[0006] A film manufacturing method according to one aspect of the present invention uses a portion of a printed film as a raw material. The printed film includes a product portion printed with a first design and an edge portion provided adjacent to at least one of both ends of the product portion in the width direction of the printed film. The film manufacturing method includes the steps of cutting the edge portion from the printed film, recovering the cut edge portion from the printed film, producing a resin raw material using the recovered edge portion, and producing a film using the resin raw material.

[0007] In this film manufacturing method, the film is manufactured using the edge portion of the printed film. According to this film manufacturing method, the product portion on which the first design is printed is not used in the manufacture of the film, and the ink forming the first design does not mix with the film, so a relatively high quality film can be manufactured even without removing the ink forming the first design.

[0008] In this method of producing a film, the printed film may be a heat-shrinkable film in a state before being heat-shrunk.

[0009] In this film manufacturing method, a second pattern may be printed on the edge portion, and the ratio of the area of ​​the second pattern to the area of ​​the edge portion may be smaller than the ratio of the area of ​​the first pattern to the area of ​​the product portion.

[0010] According to this film manufacturing method, the ratio of the area of ​​the second pattern to the area of ​​the ear portion is smaller than the ratio of the area of ​​the first pattern to the area of ​​the product portion, and the amount of ink mixed into the film is relatively small, so a relatively high quality film can be manufactured even without removing the ink that forms the second pattern.

[0011] In this method of manufacturing a film, the ratio of the area of ​​the second pattern to the area of ​​the edge portion may be 70% or less.

[0012] According to this film manufacturing method, the ratio of the area of ​​the second pattern to the area of ​​the edge portion is 70% or less, and the amount of ink mixed into the film is small, so a relatively high quality film can be manufactured even without removing the ink that forms the second pattern.

[0013] In this film manufacturing method, in the step of recovering the selvage portions, the selvage portions cut from the printed film may be wound up.

[0014] According to this film manufacturing method, the selvage portions are collected by being wound up after being cut from the printed film, so that the selvage portions can be collected efficiently.

[0015] In this film manufacturing method, the ears may be provided at positions adjacent to each of both ends of the product portion in the width direction, and in the step of cutting the ears, the ears provided at positions adjacent to each of both ends of the product portion in the width direction may be cut from the printed film, and in the step of recovering the ears, each ear cut from the printed film may be wound up on a common roll.

[0016] According to this film manufacturing method, each edge cut from both ends of the printed film is recovered by being wound up on a common roll, allowing for efficient recovery of the edge portions.

[0017] This method for producing a film may further include the steps of measuring the color of the resin raw material or the film, and adjusting the amount of the resin raw material used in producing the film based on the results of the measurement.

[0018] According to this film manufacturing method, the amount of resin raw material used in film manufacturing is adjusted based on the measurement results of the color of the resin raw material or the film, so that the quality of the manufactured film can be maintained at a predetermined level or above.

[0019] The film produced by this method may have a haze value of 16% or less.

[0020] A roll according to another aspect of the present invention is a roll of a portion of a printed film. The printed film includes a product portion on which a design is printed and an ear portion provided adjacent to at least one of both ends of the product portion in the width direction of the printed film. The roll includes a cylindrical winding core and the ear portion wound circumferentially around the winding core.

[0021] In this winding body, the selvage portions of the printed film are wound around the winding core. With this winding body, since the selvage portions are wound around the winding core, it is possible to easily manufacture film using the selvage portions.

[0022] A film according to another aspect of the present invention is a film in which a portion of a printed film is used as a raw material. The printed film includes a product portion on which a first design is printed and an edge portion provided adjacent to at least one of both ends of the product portion in the width direction of the printed film. A second design is printed on the edge portion. The ratio of the area of ​​the second design to the area of ​​the edge portion is smaller than the ratio of the area of ​​the first design to the area of ​​the product portion. The edge portion is a portion of the printed film. The haze value of the film is 16% or less.

[0023] According to the present invention, it is possible to provide a film manufacturing method that uses printed film as a raw material and that can produce relatively high-quality film when the ink on the printed film is not removed, a roll used in the manufacturing method, and a film manufactured by the manufacturing method.

[0024] FIG. 1 is a diagram schematically showing a resource circulation system. FIG. 2 is a plan view schematically showing an example of a printed film. FIG. 3 is a diagram schematically showing a cross section taken along line III-III in FIG. 2. FIG. 4 is a plan view schematically showing an edge portion recovery device. FIG. 5 is a front view schematically showing an edge portion recovery device. FIG. 6 is a diagram schematically showing the configuration of a resin raw material production device. FIG. 7 is a diagram schematically showing the configuration of a film production device. FIG. 8 is a flowchart showing the film production procedure in the resource circulation system.

[0025] An embodiment according to one aspect of the present invention (hereinafter also referred to as "the present embodiment") will be described in detail below with reference to the drawings. Note that identical or corresponding parts in the drawings are designated by the same reference numerals, and their description will not be repeated. Furthermore, for ease of understanding, each drawing is drawn in a schematic manner with objects appropriately omitted or exaggerated.

[0026] [1. Overview] In recent years, marine pollution caused by plastic waste has become a global problem. Resource recycling has attracted attention as a means to address this problem.

[0027] Fig. 1 is a schematic diagram showing a resource circulation system S1 that uses a film manufacturing method according to the present embodiment. Referring to Fig. 1, in the resource circulation system S1, a resin film printed with a design (hereinafter also referred to as "printed film") is recycled to produce new film. The printed film is, for example, a heat-shrinkable film or packaging bag that can be used for food, beverages, medicines / medical products, cosmetics, toiletries, industrial / agricultural products, etc.

[0028] FIG. 2 is a plan view schematically illustrating an example of a printed film. In this example, the printed film 40 is a heat-shrinkable film before heat shrinking. As shown in FIG. 2, the printed film 40 includes a product portion 400 and edge portions 410A and 410B. The edge portions 410 are located adjacent to both ends of the product portion 400 in the width direction. A design is printed on each of the product portion 400 and the edge portions 410. Hereinafter, the design printed on the product portion 400 will also be referred to as the "product portion design," and the design printed on the edge portions 410 will also be referred to as the "edge portion design." The ratio of the area of ​​the edge portion design to the area of ​​the edge portion 410 is 70% or less, preferably 50% or less, more preferably 30% or less, and even more preferably 15% or less. The ratio of the area of ​​the ear portion pattern to the area of ​​the ear portion 410 is smaller than the ratio of the area of ​​the product portion pattern to the area of ​​the product portion 400 .

[0029] Product section 400 is used for packaging plastic containers, glass containers, paper containers, etc. Information for checking the printing status of product section 400 is printed on each of edge sections 410A, 410B. That is, edge section 410 is used for checking the printing status of product section 400. Register marks 412A and color control marks 416 are printed on edge section 410A. Register marks 412B, slit lines 414, and color bars 418 are printed on edge section 410B.

[0030] Printing on the film is performed, for example, using a gravure plate. The registration marks 412 are used to align the gravure plate when printing the design. The slit lines 414 are used when cutting the edge portions 410 from the printed film 40. The color control marks 416 are composed of multiple triangles and are used to align the color plates. The color control marks 416 include a triangle for each color used in printing. The color bar 418 is used to check the quality of the density of each printed color.

[0031] Referring again to Figure 1, the resource circulation system S1 includes an edge portion recovery device 10, a resin raw material production device 20, and a film production device 30. The edge portion recovery device 10 is configured to cut edge portions 410 from printed film 40 and recover the cut edge portions 410. The resin raw material production device 20 is configured to produce a resin raw material by using the edge portions 410 recovered by the edge portion recovery device 10. The film production device 30 is configured to produce a film by using the resin raw material produced by the resin raw material production device 20.

[0032] The film produced by the film production device 30 is again printed. That is, the printed film 40 is again produced. The selvage portions 410 contained in the produced printed film 40 are again collected by the selvage portion collection device 10 and used to produce new film. Resource circulation is achieved by repeating this cycle.

[0033] In this way, in resource circulation system S1, film is produced by using edge portion 410 of product portion 400. According to resource circulation system S1, product portion 400 printed with a relatively large design is not used in the production of film, and the ink forming the product portion design does not mix with the film, so a relatively high-quality film can be produced even without removing the ink forming the product portion design.

[0034] [2. Structure] <2-1. Structure of the Printed Film> Figure 3 is a diagram schematically showing the III-III cross section of Figure 2. As shown in Figure 3, the printed film 40 includes a resin layer 42 and a printing layer 44. The printing layer 44 is composed of a coloring component such as ink that forms a pattern. In this embodiment, the object to be packaged is placed on the printing layer 44 side. In other words, when packaging is performed using the printed film 40, the printing layer 44 is located on the inside. An inner coat layer may be provided on the printing layer 44, and an overcoat layer may be provided on the resin layer 42.

[0035] The resin layer 42 may be composed of a single layer or multiple laminated layers. The resin layer 42 may include a layer in which different types of resins are mixed, or multiple layers each containing a different type of resin. Each layer constituting the resin layer 42 may contain components other than resin. Each layer may contain metal components such as aluminum, antiblocking agents, additives, etc. Examples of additives include heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, lubricants, antistatic agents, flame retardants, antibacterial agents, and fluorescent brighteners.

[0036] Examples of the resin contained in each layer include polyolefin-based resins, polystyrene-based resins, polyamide-based resins, and polyester-based resins. Examples of polyolefin-based resins include polypropylene-based, polyethylene-based, and cyclic polyolefin-based resins. Examples of polystyrene-based resins include styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-isoprene-butadiene copolymers, styrene-acrylic copolymers, acrylonitrile-butadiene-styrene copolymers, and acrylonitrile-styrene copolymers. Examples of polyamide-based resins include aliphatic polyamides such as nylon 6-based resins, nylon 66-based resins, and nylon 12-based resins, aromatic polyamides, amorphous polyamides, and polyamide elastomers. Examples of polyester-based resins include those obtained by condensation polymerization of a dicarboxylic acid component and a diol component. The type of the dicarboxylic acid component is not particularly limited, and examples thereof include terephthalic acid, o-phthalic acid, isophthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, octyl succinic acid, cyclohexanedicarboxylic acid, naphthalenedicarboxylic acid, fumaric acid, maleic acid, itaconic acid, decamethylenecarboxylic acid, anhydrides thereof, and lower alkyl esters thereof. The type of the diol component is also not particularly limited, and examples thereof include ethylene glycol, 1,3-propanediol, 1,4-butanediol, diethylene glycol, 1,5-pentanediol, 1,6-hexanediol, dipropylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-butanediol, 2,3-butanediol, neopentyl glycol (2,2-dimethylpropane-1,3-diol), 1,2-hexanediol, 2,5- Examples of the diol include aliphatic diols such as hexanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, and polytetramethylene ether glycol; and alicyclic diols such as 2,2-bis(4-hydroxycyclohexyl)propane, alkylene oxide adducts of 2,2-bis(4-hydroxycyclohexyl)propane, 1,4-cyclohexanediol, and 1,4-cyclohexanedimethanol.

[0037] 2-2. Configuration of the Selvage Part Recovery Device Fig. 4 is a plan view schematically showing the selvage part recovery device 10. Fig. 5 is a front view schematically showing the selvage part recovery device 10. Referring to Figs. 4 and 5, the selvage part recovery device 10 includes an unwinding roll 100, a take-up roll 110, cutting mechanisms 120A and 120B, and transport rolls 140, 150, 160, and 170.

[0038] A roll of printed film 40 is attached to unwind roll 100. Unwind roll 100 is configured to unwind printed film 40 by rotating. Cutting mechanisms 120A and 120B are configured to cut selvage portions 410A and 410B from printed film 40, respectively. Cutting mechanisms 120A and 120B are provided near transport rolls 140 and 150, respectively. Each of cutting mechanisms 120A and 120B has, for example, a rotary blade, and cuts selvage portions 410 from printed film 40 by rotating the rotary blade. Cutting mechanism 120B also has a sensor that detects slit lines 414 (see FIG. 2), and cutting mechanisms 120A and 120B are positioned in the width direction based on the detection results of the sensor.

[0039] The product portion 400 manufactured by cutting out the selvage portions 410A and 410B is wound up by a winding roll (not shown). Meanwhile, the selvage portions 410A and 410B are transported downward by the transport rolls 140 and 150, respectively. The selvage portions 410 are then transported downstream by the transport rolls 160 and 170 and wound up by the winding roll 110. The winding roll 110 repeatedly moves back and forth (traverses) in a direction perpendicular to the transport direction of the selvage portions 410 after passing through the transport rolls 160 and 170 in a plan view. This forms a wound body of the selvage portions 410. In this wound body, the selvage portions 410 are wound circumferentially around a cylindrical winding core.

[0040] In this way, the selvage portion recovery device 10 recovers the selvage portions 410 by winding up the selvage portions 410 cut from the printed film 40. Therefore, the selvage portion recovery device 10 can efficiently recover the selvage portions 410. It also makes it easier to use the selvage portions 410 in subsequent processes.

[0041] Furthermore, in the selvage recovery device 10, the selvages 410A, 410B cut from both ends of the product part 400 are recovered by being wound up on a common winding roll 110. Therefore, the selvage recovery device 10 can more efficiently recover the selvages 410.

[0042] 6 is a diagram schematically illustrating the configuration of the resin raw material manufacturing apparatus 20. As shown in Fig. 6, the resin raw material manufacturing apparatus 20 includes an unwinding roll 200, a twisting mechanism 210, a compression mechanism 220, and a cutting mechanism 230.

[0043] A winding body of the selvage portion 410 is attached to the unwinding roll 200. The unwinding roll 200 is configured to unwind the selvage portion 410 by rotating. The selvage portion 410 unwound by the unwinding roll 200 still has the selvage portion design printed on it. In other words, when the selvage portion 410 is turned into raw material, the selvage portion design is not removed (de-inked).

[0044] The twisting mechanism 210 has a rotation axis parallel to the conveyance path of the ear portions 410, and is configured to twist the ear portions 410 by rotating. The compression mechanism 220 is configured to compress the ear portions 410 twisted by the twisting mechanism 210, thereby densifying the ear portions 410. The cutting mechanism 230 is configured to cut the ear portions 410 compressed by the compression mechanism 220. In this way, pellet-shaped resin raw material 50 is produced.

[0045] In the resin raw material manufacturing apparatus 20, the ear portions 410 are processed into the resin raw material 50 without going through a melting step. Therefore, the resin raw material manufacturing apparatus 20 can suppress deterioration of the resin raw material 50 due to thermal history.

[0046] 7 is a diagram schematically illustrating the configuration of the film production apparatus 30. As shown in Fig. 7, the film production apparatus 30 includes a T-die 300, cast rolls 310 and 320, a longitudinal stretching machine 340, and a transverse stretching machine 350.

[0047] The T-die 300 includes a T-die main body 301 and raw material input sections 330, 331, and 332. In this example, the resin layer 42 (see FIG. 3 ) is composed of three layers. The central layer (intermediate layer) of the three layers constituting the resin layer 42 is composed of raw material input into the raw material input section 331. The resin raw material is input into the raw material input section 331. In addition to the resin raw material 50, at least one of virgin raw material, recycled raw material, and biomass raw material may be input into the raw material input section 331. Virgin raw material refers to raw material that has never been used in film production. Recycled raw material includes at least one of raw material regenerated by chemical recycling, raw material regenerated by mechanical recycling, and raw material regenerated by material recycling. In this example, the resin raw material 50 is not input into either of the raw material input sections 330 and 332.

[0048] The proportion of the resin raw material 50 in the raw materials fed into the raw material feed section 331 is 45 wt% or less, preferably 30 wt% or less, more preferably 15 wt% or less, even more preferably 7.5 wt% or less, and particularly preferably 4.5 wt% or less. The proportion of the resin raw material 50 in all the raw materials fed into the raw material feed sections 330, 331, and 332 is 30 wt% or less, preferably 20 wt% or less, more preferably 10 wt% or less, even more preferably 5 wt% or less, and particularly preferably 3 wt% or less.

[0049] The T-die body 301 is configured to co-extrude the raw materials introduced through the raw material introduction sections 330, 331, and 332, thereby fusing the molten materials introduced into each raw material introduction section to form a single integrated film (molten material). The cast rolls 310 and 320 are configured to cool the extruded molten material and send it downstream. The longitudinal stretching machine 340 stretches the molten material cooled by the cast rolls 310 and 320 in the MD (machine direction). The transverse stretching machine 350 stretches the film stretched in the MD (transverse direction) in the TD (transverse direction).

[0050] The film 60 that has been subjected to various stretching processes is wound up by a winding roll (not shown) located downstream. A roll of the film 60 is produced through the manufacturing process in the film manufacturing apparatus 30.

[0051] The haze value of the film 60 is 16% or less, preferably 14% or less, more preferably 10% or less, even more preferably 7% or less, and particularly preferably 6.5% or less. Furthermore, with respect to the film 60, in the L*a*b* color space, L* is, for example, 89 or more and 93.6 or less, a* is, for example, −1.8 or more and −0.22 or less, and b* is, for example, 4.2 or more and 9.5 or less.

[0052] The resin raw material 50 and the film 60 recycled from it may contain a (meth)acrylic ester resin. A (meth)acrylic ester resin is often applied as an overcoat to the surface of the printed layer 44 included in the printed film 40. A (meth)acrylic ester resin may also be included in the ink that constitutes the printed layer 44 included in the printed film 40. However, a (meth)acrylic ester resin is generally not used as the main component of a film because it may reduce the transparency of the film. Therefore, if the resin raw material 50 contains a (meth)acrylic ester resin, such a resin raw material is considered to be a recycled product. Furthermore, if the printed film 40 has a layer containing a (meth)acrylic ester resin in addition to the overcoat layer and the printed layer 44, such a printed film 40 is considered to be a recycled product. The content of the (meth)acrylic ester resin in the film 60 is 0.7 wt % or less.

[0053] 3. Film Manufacturing Procedures Figure 8 is a flowchart showing the manufacturing procedures for the film 60 in the resource circulation system S1. Referring to Figure 8, the selvage portion recovery device 10 cuts selvage portions 410 from the printed film 40 (step S100). The selvage portion recovery device 10 winds up the cut selvage portions 410 to form a roll of selvage portions 410 (step S110). The resin raw material manufacturing device 20 uses the selvage portions 410 unwound from the roll to manufacture the resin raw material 50 (step S120). The film manufacturing device 30 uses the resin raw material 50 to manufacture the film 60 (step S130).

[0054] [4. Features] As described above, in resource circulation system S1 that uses the film manufacturing method according to this embodiment, film 60 is manufactured by using selvage portion 410 of printed film 40. According to resource circulation system S1, product portion 400 printed with a product portion design is not used in manufacturing film 60, and the ink that forms the product portion design does not mix with film 60. Therefore, it is possible to manufacture film 60 of relatively high quality even without removing the ink that forms the product portion design.

[0055] Furthermore, according to the resource circulation system S1, the ratio of the area of ​​the selvage pattern to the area of ​​the selvage 410 is smaller than the ratio of the area of ​​the product portion pattern to the area of ​​the product portion 400, and the amount of ink mixed into the film 60 is relatively small, so that a relatively high quality film 60 can be produced even without removing the ink that forms the selvage pattern.

[0056] [5. Other Embodiments] The concept of the above embodiment is not limited to the embodiment described above. Hereinafter, an example of another embodiment to which the concept of the above embodiment can be applied will be described.

[0057] <5-1> In the above embodiment, in the selvage portion recovery device 10, the selvage portions 410A and 410B are wound up by the common winding roll 110. However, the selvage portions 410A and 410B do not necessarily have to be wound up by the common winding roll 110. The selvage portions 410A and 410B may be wound up by different winding rolls.

[0058] <5-2> In the above embodiment, the resin raw material 50 is introduced into the raw material introduction section 331 at a predetermined rate in the film manufacturing apparatus 30. However, the rate of the resin raw material 50 introduced into the raw material introduction section 331 may be adjusted, for example, periodically. For example, color measurement of the resin raw material 50 or film 60 to be manufactured may be performed periodically, and the amount of resin raw material 50 used to manufacture the film 60 may be adjusted based on the measurement results. Specifically, the introduction rate of the resin raw material 50 may be reduced if any of the L*a*b* values ​​of the resin raw material 50 or film 60 to be manufactured falls outside a predetermined range. Furthermore, the introduction rate of the resin raw material 50 may be reduced if the haze value of the resin raw material 50 or film 60 to be manufactured falls outside a predetermined range.

[0059] <5-3> In the above embodiment, the ears 410 are twisted as they are by the twisting mechanism 210 in the resin raw material manufacturing apparatus 20. However, the ears 410 do not necessarily have to be twisted as they are. For example, a cutting mechanism that cuts the ears 410 into thinner pieces may be provided between the unwinding roll 200 and the twisting mechanism 210. The ears 410 unwound by the unwinding roll 200 may be cut into thinner pieces by the cutting mechanism, and the cut ears 410 may be twisted by the twisting mechanism 210. This makes it easier to twist the ears 410.

[0060] In the above embodiment, the ear portions 410 are processed into a resin raw material by using the resin raw material manufacturing apparatus 20. However, the method of converting the ear portions 410 into a resin raw material is not limited to this. For example, the ear portions 410 collected by the ear portion recovery device 10 may be finely cut to produce a fluff-like resin raw material. Alternatively, the ear portions 410 collected by the ear portion recovery device 10 may be shredded and then melt-extruded to form strands, and the strands may be cut with a pelletizer to produce a pellet-like resin raw material. Alternatively, for example, the ear portions 410 may be processed using the resin raw material manufacturing apparatus 20, the processed ear portions 410 may be melt-extruded to form strands, and the strands may be cut with a pelletizer to produce a pellet-like resin raw material.

[0061] The above describes exemplary embodiments of the present invention. That is, the detailed description and the accompanying drawings are disclosed for the purpose of illustrative explanation. Therefore, some of the components described in the detailed description and the accompanying drawings may be non-essential components for solving the problems. Therefore, just because these non-essential components are described in the detailed description and the accompanying drawings, it should not be immediately recognized that these non-essential components are essential.

[0062] Furthermore, the above-described embodiments are merely illustrative of the present invention in all respects. Various improvements and modifications to the above-described embodiments are possible within the scope of the present invention. For example, at least a portion of the configuration of any of the embodiments may be combined with at least a portion of the configuration of any of the other embodiments. In other words, when implementing the present invention, specific configurations can be appropriately adopted depending on the embodiment.

[0063] Examples of the present invention will be described below, but the present invention is not limited to the following examples.

[0064] [1. Reference Example and Examples] Films for Reference Example and Examples 1-6 were produced. The film for Reference Example was produced without using the resin raw material 50 described above. The films for Examples 1-6 were produced using the resin raw material 50 described above. In the edge 410 (printed edge) used to produce the resin raw material 50, the ratio of the area of ​​the edge pattern to the area of ​​the edge 410A was 3%, and the ratio of the area of ​​the edge pattern to the area of ​​the edge 410B was 19%. A roll of printed edge was formed using the above-described edge recovery device 10, and the resin raw material 50 was produced using the resin raw material production device 20. The resin layer of the printed edge was composed of polyester-based resin / polystyrene-based resin / polyester-based resin. Here, the polyester-based resin was a polyester-based resin composed of a dicarboxylic acid component and a diol component, and the polystyrene-based resin was a styrene-butadiene copolymer. In the printed edge, the thickness of the surface layer:thickness of the middle layer:thickness of the back layer was 1:5:1 to 1:8:1.

[0065] The raw material compositions constituting each layer were fed into an extruder with a barrel temperature of 160 to 200°C, extruded through a multilayer die at 200°C into a three-layer sheet, and cooled and solidified by a take-up roll at 50°C. Next, the film was stretched at a draw ratio of 3.5 in a tenter stretching machine with a preheating zone of 102°C, a stretching zone of 89 to 91°C, and a heat setting zone of 86°C, and then taken up by a winder, to produce a film in which the direction perpendicular to the main shrinkage direction was MD and the main shrinkage direction was TD.

[0066] In each of the films of the Reference Example and Examples 1-6, the front and back layers were each composed of a polyester-based resin (a polyester-based resin composed of a dicarboxylic acid component and a diol component). In each of the front and back layers of the films of the Reference Example and Examples 1-6, the weight percent concentration of the polyester-based resin was 100 wt%. The intermediate layer of the film of the Reference Example was composed of a polystyrene-based resin (styrene-butadiene copolymer). In the intermediate layer of the film of the Reference Example, the weight percent concentration of the polystyrene-based resin was 100 wt%. The intermediate layer of each of the films of Examples 1-6 was composed of a polystyrene-based resin (styrene-butadiene copolymer) and a printed selvedge. In Examples 1-6, the weight percent concentrations of the polystyrene-based resin and the printed selvedge were different from each other. The blending ratios of raw materials in each layer of the films of the Reference Example and Examples 1-6 were as shown in Table 1 below.

[0067] In each of the films of Reference Example and Examples 1-6, the overall thickness of the film was 35 μm, and the ratio of the thickness of the surface layer: the thickness of the intermediate layer: the thickness of the back layer was 1:6:1.

[0068] [2. Various Measurements] <2-1. Haze Value> The haze value was measured using a haze meter (NDH5000, manufactured by Nippon Denshoku Industries Co., Ltd.) at a temperature of 23° C. according to a method in accordance with JIS Z7136. The haze value was measured using four samples, and the average value was calculated.

[0069] <2-2. L*a*b* Values ​​and Color Difference> The obtained film was cut into a sample measuring 100 mm MD x 100 mm TD, and the L*, a*, and b* values ​​expressed in the L*a*b* color system were measured using a color difference meter (Spectrophotometer CM-600d manufactured by Konica Minolta Japan Inc.) (N=10), and the average value was calculated. From the average values ​​of the L*, a*, and b* values, the color difference (ΔE*ab) was calculated using the following CIE 1976 L*a*b* color difference formula: ΔE*ab=[(ΔL*) ２ +(Δa*) ２ +(Δb*) ２ ] 1 / ２

[0070] 2-3. Wet Heat Shrinkage A sample measuring 100 mm in MD x 100 mm in TD was cut out from the film. The obtained sample was immersed in boiling water at 100°C and warm water at 80°C for 10 seconds, then removed and immersed in water at 15°C for 5 seconds. The MD heat shrinkage was calculated according to the following formula (1), and the TD heat shrinkage was calculated according to the following formula (2). LMD is the MD length (mm) of the sample after heat shrinkage, and LTD is the TD length (mm) of the sample after heat shrinkage. The heat shrinkage was measured using two samples for each temperature condition of 100°C and 80°C, and the average value was calculated. Heat shrinkage (%) = {(100 - LMD) / 100} x 100 (1) Heat shrinkage (%) = {(100 - LTD) / 100} x 100 (2)

[0071] <2-4. Young's modulus> A sample measuring 250 mm in MD x 5 mm in TD was cut out from the film. Young's modulus was measured at a temperature of 23°C using a Strograph VE-1D manufactured by Toyo Seiki Seisaku-sho, Ltd., in accordance with a method in accordance with ASTM D882. The Young's modulus was measured using four samples, and the average value was calculated.

[0072] <2-5. Tensile Strength and Elongation> The film was cut into a strip measuring 10 mm wide x 100 mm long (the lengthwise direction was the same as the measurement direction of the film), and a line was drawn near the center of the lengthwise direction so that the distance between the gauge lines was 40 mm to prepare a measurement sample. The tensile strength and elongation of this measurement sample were measured using a tensile tester (Strograph VE1D, manufactured by Toyo Seiki Seisaku-sho, Ltd.) according to a method conforming to JIS-K7127. The measurement ambient temperature was 23°C, the chuck distance was the same as the gauge line, 40 mm, and the gauge line portion was clamped between the chucks and pulled at a speed of 200 mm / min until the sample broke. The tensile breaking elongation was calculated from the chuck distance before the test and the chuck distance at break. The tensile breaking strength at break was then recorded. The test was performed four times, and the average value was calculated.

[0073] [3. Measurement Results] The measurement results for each measurement item are shown in Table 2 below.

[0074] Each of the films of Examples 1-6 exhibited sufficient performance comparable to that of the Reference Example in terms of wet heat shrinkage, Young's modulus, and tensile strength and elongation. Furthermore, each of the films of Examples 1-6 also exhibited haze, L*a*b*, and color difference at levels that are practically acceptable. In terms of appearance, the films of Examples 1, 2, and 3 were particularly excellent (Rating A), followed by the films of Examples 4 and 5 (Rating B), and the film of Example 6 (Rating C).

[0075] 10 Selvage recovery device, 20 Resin raw material manufacturing device, 30 Film manufacturing device, 40 Printed film, 42 Resin layer, 44 Printed layer, 50 Resin raw material, 60 Film, 100, 200 Unwinding roll, 110 Winding roll, 120 Cutting mechanism, 140, 150, 160, 170 Conveying roll, 210 Twisting mechanism, 220 Compression mechanism, 230 Cutting mechanism, 300 T-die, 301 T-die body, 310, 320 Cast roll, 330, 331, 332 Raw material input section, 340 Longitudinal stretching machine, 350 Transverse stretching machine, 400 Product section, 410 Selvage, 412 Registration mark, 414 Slit line, 416 Color control mark, 418 Color bar, S1 Resource circulation system.

Claims

1. A method for manufacturing a film using a printed film as a raw material, wherein the printed film includes a product portion on which a first pattern is printed and an ear portion provided at a position adjacent to at least one of both ends of the product portion in the width direction of the printed film, the method comprising: a step of cutting the ear portion from the printed film; a step of collecting the ear portion cut from the printed film; a step of manufacturing a resin raw material by using the collected ear portion; and a step of manufacturing a film by using the resin raw material.

2. The method for manufacturing a film according to claim 1, wherein the printed film is a heat-shrinkable film in a state before heat shrinkage.

3. The method for manufacturing a film according to claim 1 or 2, wherein a second pattern is printed on the ear portion, and a ratio of an area of the second pattern to an area of the ear portion is smaller than a ratio of an area of the first pattern to an area of the product portion.

4. The method for manufacturing a film according to claim 3, wherein the ratio of the area of the second pattern to the area of the ear portion is 70% or less.

5. The method for manufacturing a film according to claim 1 or 2, wherein in the step of collecting the ear portion, the ear portion cut from the printed film is wound up.

6. The method for manufacturing a film according to claim 5, wherein the ear portion is provided at a position adjacent to each of both ends of the product portion in the width direction, in the step of cutting the ear portion, the ear portion provided at a position adjacent to each of both ends of the product portion in the width direction is cut from the printed film, and in the step of collecting the ear portion, each ear portion cut from the printed film is wound up by a common roll.

7. The method for manufacturing a film according to claim 1 or 2, further comprising: a step of measuring a color of the resin raw material or the film; and a step of adjusting an amount of the resin raw material used for manufacturing the film based on a result of the measurement.

8. The method for manufacturing a film according to claim 1 or 2, wherein in the film, a haze value is 16% or less.

9. A take-up body for a part of a printed film, wherein the printed film includes a product portion on which a pattern is printed and an ear portion provided at a position adjacent to at least one of both ends of the product portion in the width direction of the printed film, and the take-up body includes a cylindrical take-up core and the ear portion wound around the take-up core in the circumferential direction.

10. A film in which a part of a printed film is used as a raw material, wherein the printed film includes a product portion on which a first pattern is printed and an ear portion provided at a position adjacent to at least one of both ends of the product portion in the width direction of the printed film, a second pattern is printed on the ear portion, a ratio of an area of the second pattern to an area of the ear portion is smaller than a ratio of an area of the first pattern to an area of the product portion, a part of the printed film is the ear portion, and a haze value of the film is 16% or less.

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