JP2012121268A - Method of manufacturing packaging film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a packing film excellent in transverse cutting properties.SOLUTION: In the method of manufacturing a packing film, the packaging film with a thickness of 3-30 μm is obtained when a polymethylpentene-1 resin composition containing (A) 100 pts.mass of polymethylpentene-1 resin, and (B) 0.5-60 pts.mass of polybutene-1 resin and/or 0.1-20 pts.mass of liquid paraffin, wherein the total amount of component (B) does not exceed 75 pts.mass, is extruded using a T die. In the extrusion, a lip opening R (μm) of the T die, the film thickness t (μm), an extrusion speed E per dice width 1 cm (cm/hr) of the resin composition extruded from the die, and an air gap A (cm) satisfy the following expression 1: 15≤(1/t-1/R)(E/At)×100≤900.

Description

The present invention relates to a packaging film that is generally used for packaging foods in general households, food sales, food and beverage provision services, and the like. More specifically, the present invention relates to a method for producing a packaging film having excellent cross-cutting properties, a packaging film obtained by the method, and a packaging film product stored in a storage box without a saw-tooth cutting aid.

Conventionally, the packaging film has been provided as a wound film stored in a rectangular parallelepiped storage box as shown in FIG. 5, from which a necessary amount is drawn and cut in a lateral direction with respect to the length direction by some method. Provided for use. As a method of cutting horizontally, the most common method is to use a long sawtooth provided on the lid plate of the storage box.

However, the saw blade has safety problems such as injury to the hand, and the problem that the paper storage box and the metal saw blade must be separated at the time of disposal. Instead, a method using a sheet to which a deformed metal powder is bonded as a cutting tool (Patent Document 1), having a processing flaw continuous in the length direction of the film, and cutting into a local part of a storage box in contact with the processing flaw area A method of forming an auxiliary tool (Patent Document 2), a method of making a cut at the end of a wound film (Patent Document 3), and the like have been proposed.

However, since the conventional wrap film is premised on cutting along the cutting tool, there is not enough countermeasures for the linear cut in the horizontal direction, and there is no consideration for the cut in a cosmetic box without a saw blade. Even if it is forcibly cut without a cutting tool, the cutting direction often turns from the middle gradually to the length direction even if it starts to cut in the horizontal direction, which is not satisfactory in practice. There wasn't.

Japanese Patent Laid-Open No. 61-217345 Japanese Patent Laid-Open No. 11-124133 JP 2001-322636 A

As a result of earnest research to obtain a packaging film having excellent cross-cutting properties, the present inventors have made the above object by forming a polymethylpentene-1-based resin composition under specific conditions using a T-die. I found that I can achieve.

That is, the present invention comprises (A) 100 parts by weight of polymethylpentene-1 resin, and (B) 0.5 to 60 parts by weight of polybutene-1 resin and / or 0.1 to 20 parts by weight of liquid paraffin, provided that the components Including extruding a polymethylpentene-1-based resin composition containing the total amount of (B) not exceeding 75 parts by mass using a T-die to obtain a packaging film having a film thickness of 3 to 30 μm, In extrusion, the lip opening R (unit: μm) of the T die, the film thickness t (unit: μm), the discharge speed E (unit: cm ³ / hr) per 1 cm of die width of the resin composition extruded from the die, and the air gap A (unit cm) is the following formula 1:
15 ≦ (1 / t − 1 / R) · (E / At ) × 100 ≦ 900 Formula 1
It is the manufacturing method of the film for packaging characterized by satisfy | filling.

Since the packaging film obtained by the method of the present invention is excellent in cross-cutting properties, the required amount of film can be removed from the box even if the box for storing the wound film does not have any cutting aids such as saw teeth. When pulling out and cutting, it can be cut easily and satisfactorily, so safety issues such as injury to the hand, paper storage box and metal saw blade must be separated at the time of disposal The problem can be fundamentally solved.

It is a figure which shows a film cutting test. It is a figure which shows a film edge part tension test. It is the figure which photographed the film surface of this invention in which knurling was given. It is the figure which photographed the film surface of this invention to which laser processing was given. It is a perspective view which shows one embodiment of the box for accommodating the film of this invention. It is a figure for demonstrating the adhesive test of a film.

The method of the present invention
(A) 100 parts by mass of polymethylpentene-1 resin and (B) 0.5 to 60 parts by mass of polybutene-1 resin and / or 0.1 to 20 parts by weight of liquid paraffin, provided that the total amount of component (B) Including extruding a polymethylpentene-1-based resin composition containing no more than 75 parts by mass using a T-die to obtain a packaging film having a film thickness of 3 to 30 μm.

Component (A) is a polymethylpentene-1 resin, and in addition to a homopolymer of 4-methylpentene-1 or 3-methylpentene-1, 4-methylpentene-1 and / or 3-methylpentene- Copolymers of 1 and other α-olefins are included. The α-olefin may be used alone or in combination of two or more. Examples of the α-olefin include ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene and the like.

Component (B) is a polybutene-1 resin and / or liquid paraffin. The polybutene-1 resin includes a copolymer of butene-1 and another α-olefin in addition to a homopolymer of butene-1. The α-olefin may be used alone or in combination of two or more. Examples of the α-olefin include ethylene, propylene, 1-hexene, 1-octene, 1-decene, 1-dodecene and the like. The above fluid paraffin is a liquid, chemically stable substance mainly composed of a chain saturated hydrocarbon, and commercially available examples (trade names) include Daphne Oil CP of Idemitsu Kosan Co., Ltd. and MORESCO Co., Ltd. Examples include Sco White and Kaneda Corporation's High Call K.

The amount of the component (B) is 0.5 to 60 parts by mass, preferably 1 to 25 parts by mass of the polybutene-1 resin with respect to 100 parts by mass of the component (A). 20 parts by mass, preferably 1 to 12 parts by mass. However, when both a polybutene-1 resin and liquid paraffin are used, the respective blending amounts are within the above range, and the total blending amount is 0.6 to 75 parts by mass, preferably 2 to 35. Part by mass, more preferably 3 to 25 parts by mass. When there is more quantity of a component (B) than the said upper limit, it will be inferior to the transversal property of the film obtained. If it is less than the above lower limit, it is inferior in adhesiveness required as a packaging film.

An auxiliary material can be added to the polymethylpentene-1 resin composition within a range that does not contradict the object of the present invention. With these auxiliary materials, physical properties required as a packaging film, for example, tackiness and transparency can be imparted and adjusted. As auxiliary materials, liquid processing aids such as thermoplastic resins other than polymethylpentene-1 resin (for example, polypropylene and polyethylene), liquid polybutene (hydrogenated polyisobutylene), antioxidants, neutralizing agents, antifogging Additives such as agents and slip agents can be mentioned. The total amount of the thermoplastic resin and the liquid processing aid is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, with respect to 100 parts by mass of the polymethylpentene-1 resin.

The method of the present invention is carried out by an extrusion film forming method using a T-die from the viewpoint of imparting a crossing property to the packaging film and from the viewpoint of productivity and film forming speed.

The packaging film produced by the method of the present invention has a thickness of 3 to 30 μm, preferably 5 to 20 μm, more preferably 8 to 15 μm. If the wall thickness is thicker than the above upper limit, sufficient crossability cannot be obtained. On the other hand, if it is thicker than the above upper limit, it becomes a rigid film, and the adhesiveness to tableware and the like becomes unsatisfactory when lapping. If the film is thinner than the above lower limit, it is inconvenient to handle, and film formation and slit processing become difficult.

In the method of the present invention, extrusion film formation using a T-die is performed under a condition that the film deformation speed until the molten film exiting the die reaches the chill roll and becomes the final size film is high. It is characterized by. That is, in the air gap from the die to the chill roll, it is necessary to draw the molten film large and quickly. In general, it is known that, in the T-die film formation, when the deformation amount and the deformation speed are increased, the longitudinal elongation of the obtained film is decreased. As a result of intensive research to obtain a packaging film with good cross-cutting properties, the present inventors have found that when a specific polymethylpentene-based resin composition is formed under specific manufacturing conditions that reduce the longitudinal elongation, Has been found to provide an improved film. Specifically, the manufacturing conditions can be expressed by the following formula 1.
15 ≦ (1 / t − 1 / R) · (E / At ) × 100 ≦ 900 Formula 1
Here, R is the lip opening (unit: μm) of the T die, t is the thickness (unit: μm) of the obtained film, and E is the discharge speed per 1 cm of die width of the resin composition extruded from the die. (Unit cm ³ / hr), and A is an air gap (unit cm).

The above formula 1 will be described below. As the deformation of the film from the die to the chill roll in T-die film formation, the deformation in the length direction of the film occupies a very large weight, so when considering the deformation speed, consider the deformation only in the length direction. Can do.

Deformation amount in the length direction When the extrusion volume of the resin in a minute time Δt from the die (width W) is ΔE, and the extrusion length at that time is Δχ,
ΔE = WRΔχ Formula 1-1
Because
Δχ = ΔE / WR Formula 1-2
It is. Here, if the film forming conditions are set so that ΔE is constant, W is constant.
Δχ = a / R (a is a proportionality constant (a = ΔE / W)) Equation 1-3
It is. On the other hand, the length of the film obtained when the amount of resin of ΔE reaches the chill roll is X, and the thickness is t. Here, the lateral deformation can be ignored because it is sufficiently small compared to the length direction, so the width of the film is W,
ΔE = WtΧ
From Equation 1-1,
WRΔχ = WtΧ
∴ Χ = RΔχ / t
It is. Therefore, from Equation 1-3:
Χ = a / t Equation 1-4
It is. Therefore, the deformation Χ−Δχ in the length direction is obtained from Equation 1-2 and Equation 1-4.
Χ−Δχ = a / ta / R = a (1 / t −1 / R) Formula 1-5
It is.

Deformation time Deformation in the longitudinal direction occurs during the time until the molten film leaves the T-die and contacts the chill roll, i.e., the time it passes through the air gap. The air gap passage time T is an average film take-off speed (V _ave ) between the air gap (A) / air gap, and the average speed (V _ave ) is approximately the film when the film reaches the chill roll. It is known to be proportional to the take-off speed (V _a ) (for example, Toshitaka Kanai, Plastics Age, 32 , (10), 168 (1986); Toshitaka Kanai, Journal of Textile Science, 41 , T-409 (1985). Toshitaka Kanai and Akira Funaki, Journal of the Textile Society, 41 , T-521 (1985); Toshitaka Kanai and Akira Funaki, Journal of the Textile Society, 42 , T-1 (1986)). Therefore, the air gap passage time T is proportional to the air gap (A) / film take-up speed (V _a ). The film take-off speed (V _a ) is proportional to the discharge speed E and inversely proportional to the film thickness t. Therefore, the time T is longer as the air gap A is longer, longer as the discharge speed E is smaller, and longer as the film thickness t is larger. Therefore, the time T can be expressed as follows.
T = b · At / E (b is a proportional constant) Formula 1-6

Deformation speed in the length direction Deformation speed in the length direction is expressed by Equations 1-5 and 1-6.
(Χ−Δχ) / T = a (1 / t −1 / R) / (b · At / E)
= C (1 / t -1 / R). (E / At) (c is a proportionality constant (c = a / b)) Formula 1-7
It is. Here, the unit of t (film thickness) and R (lip opening) is μm, the unit of E (discharge speed) is cm ³ / hr, and the unit of A (air gap) is cm, Using these units, the unit of the above formula is
(1 / μm) · {(cm ³ / hr) / (cm · μm)} = (cm ² / μm ² ) · (1 / hr) = (1 / hr) × 10 ⁸
It is. For simplification, the proportionality constant c is set to 1 × 10 ⁶ in the above formula 1. That is, Formula 1 simply represents the longitudinal deformation speed.

In order to obtain a packaging film with good cross-cutting properties, which is the object of the present invention, the value of Formula 1 needs to be 15 or more. Preferably it is 25 or more. The upper limit is an area where film forming stability cannot be ensured even when a vacuum chamber, an ear jet or the like is used, and is about 900 considering the general capability of the current film forming machine.

In order to satisfy Equation 1, t is made thin, specifically considering the handleability as a product, preferably 5 to 20 μm, more preferably 8 to 15 μm, and A is shortened, specifically 0. 0.5 to 2 cm, and E is increased within a range in which film forming stability can be ensured. Specifically, although it depends on the specifications of the film forming machine, it can be set to 100 cm ³ / hr or more. Since R has a small influence in Formula 1, it is possible to select a numerical value that facilitates film formation in consideration of film formation stability, extrusion load, and the like. Specifically, it depends on the specifications of the film forming machine. However, it is about 300-900 micrometers. Of course, the value of each parameter is not limited to these numerical values as long as Expression 1 is satisfied. For example, parameter values used in the embodiments can be used.

The packaging film obtained by the above method is excellent in cross-cutting properties and has the following physical property values.
(1) The cutting deviation amount (δ) in the film cutting test is 10 mm or less.
(2) The end tensile elongation (P) in the length direction of the film is 120% or less, and (3) the end tensile elongation (P) in the length direction of the film and the end tensile elongation in the lateral direction (Q ) And the ratio P / Q is 0.25 or less.

The cutting deviation amount (δ) is a physical property value that directly indicates the cross-cutting property of the film. The film cutting test for measuring the physical property values is performed as shown in FIG. That is, a rectangular test piece having side α (length 300 mm) and side β (length 220 mm) is prepared (where side α is parallel to the length direction of the film), and the center of one side α is prepared. A 3 mm long cut is made in the part, and the film is cut by pulling both corners on the side α side where the cut is made with a human hand. The maximum deviation (unit: mm) between the cut line of the film when cut and the reference line drawn perpendicularly to the other side α from the cut is the cut deviation (δ).

In the film of the present invention, the amount of cutting deviation (δ) is 10 mm or less. Films larger than 10 mm are inferior in cross-cutability. Naturally, when the film is cut, it is ideal that the film is cut along the reference line, and the cut deviation (δ) is preferably small. Practically, it is preferably 6 mm or less.

Furthermore, the film of this invention has the physical-property value of said (2) and (3). Even if the amount of cutting deviation of the film is 10 mm or less, if the film is elongated in the longitudinal direction at the time of testing the amount of cutting deviation, the actual use will be hindered, and the cross-cutting property will be extremely bad. . The physical property values of the above (2) and (3) are indices indicating that such a film does not cause such longitudinal elongation, and thus is a touch-sensitive film having good cross-cutting properties. The end tensile elongation (P) in the length direction indicates the ability to respond to the force to cut the film by deforming. The ratio P / Q is the ratio of the likelihood of lateral elongation and longitudinal elongation when attention is paid to the fact that the transverse direction (CD) is cut when the tensile direction is the length direction (MD). The larger the is, the easier it is for the longitudinal elongation to occur, which is not preferable. In the film of the present invention, the P is 120% or less, preferably 100% or less, and the ratio P / Q is 0.25 or less, preferably 0.20 or less.

The above P and Q are measured by the film end tensile test shown in FIG. For the end tensile test in the length direction of the film, a rectangular test piece having side A (length 60 mm) and side B (length 20 mm) is prepared (where side A is the length direction of the film (MD Direction), and the elongation at break of the test piece when one of the sides A of the test piece is pulled at a pulling speed of 200 mm / min is measured, and this is defined as (P). The film end tensile test in the transverse direction (CD direction) is measured in the same manner as the above measurement except that the side A of the test piece is parallel to the transverse direction (CD direction) of the film. In the above-described tensile test, the tensile part is not the center of the test piece but the end part because it is normal that the end part is gripped and pulled during actual film cutting.

The packaging film of the present invention preferably has the following characteristics.

(4) End tensile breaking force in the MD direction (A)
The tensile breaking force at the end of the film is an index of how much the breaking propagates. When the said tensile breaking force is too small, it is not suitable for use for packaging. On the other hand, if it is too large, as described below, it is disadvantageous when the wound film accommodated in the box having no cutting aid is pulled out of the box and cut. When using a box that does not have a cutting aid, that is, a box that merely consists of cardboard, the film is cut off from the front end plate and / or the front plate of the lid plate. This is performed at the ridge line portion of the bottom plate (see FIG. 5). If the strength of the film is much higher than practically required, the cardboard will be lost when the film is cut, and the storage box will be damaged, and the box will be reinforced so that the cardboard will not lose. And increasing the thickness is not economical. That is, it is not preferable that the film has an unnecessarily high strength.

The film of the present invention preferably has a tensile breaking force of 1 to 15N. More preferably, the upper limit is 10N. The lower limit is sufficient if it is 1N or more, more preferably 2N or more, based on the demand for packaging.

The end tensile breaking force (A) in the MD direction (length direction) is measured by the film end tensile test described above. That is, as shown in FIG. 2, a rectangular test piece having side A (length 60 mm) and side B (length 20 mm) is prepared (where side A is parallel to the length direction of the film). ), The force (unit: N) at the time of breaking the test piece when one of the sides A of the test piece is pulled at a pulling speed of 200 mm / min.

(5) End tensile breaking force in the CD direction (b)
The end tensile breaking force (b) in the CD direction is preferably 15 N or less, and more preferably 10 N or less, for the same reason as the end tensile breaking force (A) in the MD direction. As for the lower limit of (b), 1N or more is sufficient, more preferably 2N or more, based on the demand for packaging. The tensile breaking force (B) is measured in the same manner as the tensile breaking force (A) except that the side A of the test piece is parallel to the lateral direction (CD direction) of the film.

Knurling, laser processing Although the packaging film of the present invention has excellent cross- cutting properties, it tends to be relatively high in strength as a film, so that it can be more easily cut in the transverse direction. It is preferable to have some kind of “trigger”. As a method therefor, there is a method of providing a cutting aid such as a file in the storage box, but if selected in accordance with the object of the present invention, knurling or laser processing is applied to the end parallel to the length direction of the film. The method of applying is most preferred.

Knurling is performed by sandwiching the film between a metal engraving roll and a metal or high hardness rubber engraving roll or a smooth roll, or by pressing the engraving roll against a roll of film. It is a process to scratch. The processing conditions should be appropriately selected depending on the material of the film, but the pressing is usually about 10 to 50 N / m. FIG. 3 shows a photograph of the film surface of the present invention that has been knurled. The knurling process can be performed by forming an independent process at the time of raw film formation, at the time of slit process, or after the slit process. The knurling process is performed on at least one of the end portions parallel to the length direction of the film, but it is more preferable to apply the knurling process to both end portions so that the film can be cut from either side. The processing width is usually 0.1 to 10 mm, preferably 0.3 to 6 mm.

Laser processing is processing in which a film is melted in a very fine region by laser irradiation heat and a concave shape or a hole is provided there. The laser to be used is not particularly limited. For example, gas lasers such as carbon dioxide laser, helium neon laser, argon ion laser and excimer laser, ruby laser using chromium-added ruby crystal as medium, titanium sapphire laser using titanium-added sapphire crystal as medium, and YAG crystal Solid state lasers such as various YAG lasers obtained by substituting yttrium with other rare earth elements and Nd: YAG lasers using neodymium-added YAG. Moreover, well-known lasers, such as a liquid laser, a semiconductor laser, a free electron laser, a metal vapor laser, a chemical laser, can be used. The irradiation output is about 0.5 to 20 W, and is appropriately adjusted in consideration of the thickness of the film and the processing speed. FIG. 4 shows a photograph of the film surface of the present invention that has been subjected to laser processing. Laser processing can be performed by forming an independent process during raw film formation, during slit processing, or after slit processing. Laser processing is applied to at least one of the end portions parallel to the length direction of the film, but it is more preferable to apply to both end portions so that the film can be cut from either side. The processing width is usually 0.1 to 10 mm, preferably 0.3 to 6 mm.

In addition, when knurling or laser processing is performed, it is possible to obtain a trouble preventing effect that the drawn end of the wound film is in close contact with the winding body and cannot be pulled out.

Storage box As a storage box for packaging film, a front plate, a bottom plate, a rear plate, a lid plate, and a lid plate are sequentially connected via a ridge line as shown in FIG. A long decorative box having a large number has been used, and conventionally, saw blades as cutting aids have been fixed to the front end portion of the lid plate and / or the ridge line portions of the front plate and the bottom plate. Since the packaging film of the present invention has excellent crossing properties as described above, such a cutting aid is not required for the storage box.

On the other hand, from the perspective of the end consumer, a storage box that had previously been provided with a metal saw blade as a cutting tool has become a simple cardboard box that does not have such a cutting tool. Can it really raise the question? Therefore, providing a very simple cutting aid may not be questioned by end consumers and may be advantageous at the sales site. As such an extremely simple cutting aid, those having a low risk of injury to the hand and improved safety are preferable, and specific examples include a fine sandpaper. A coarse grain may cause the abrasive grains to peel off, and is not suitable as a cutting aid for packaging films, particularly food packaging films. The possibility of peeling of the abrasive grains can be simply determined by whether a crack is observed on the file surface by a 180-degree bending test. For example, in the case of commercially available sandpaper (manufactured by Noritake Coated Abrasive Co., Ltd., water-resistant type sandpaper, product name C947H), cracks are observed when the grain size (according to JIS R6001 (1998)) is # 220 and coarser. # 240, very fine cracks were observed, and # 320 and finer cracks were not observed, so that a particle size of at least # 240 or finer should be used, preferably # 320 Or it is judged that something finer than that should be used. Table 1 below shows the results of 180-degree bending tests of various particle sizes of the commercially available sandpaper.

Whether or not the film can be cut with a very simple cutting aid such as sandpaper can be determined by the abrasive grain cutability test described below. As can be seen from the results of the test described below, the film of the present invention can be sufficiently applied to a storage box using sandpaper as a cutting aid.

The method of providing sandpaper in the storage box is not particularly limited, and a paint containing abrasive grains is directly applied to the front end portion of the lid plate and / or the upper end portion of the front plate and / or the ridge line portion of the front plate and the bottom plate. -The method of hardening, the method of sticking it to the said part of a storage box after apply | coating and hardening the coating material containing an abrasive grain to base materials, such as paper, etc. are mentioned. Further, a sandpaper may be provided over the entire length from the end of the heel cover plate and / or the upper end of the front plate and / or the edge of the ridgeline portion of the front and bottom plates, or a part of the total length. For example, you may provide only in an edge part. Further, a sandpaper may be provided in another part of the storage box in addition to or instead of the above part of the storage box.

EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to a following example. The materials and measurement methods used are as follows.

material
Poly-4-methylpentene-1 resin MX-002O: poly-4-methylpentene-1 manufactured by Mitsui Chemicals, MFR (260 ° C., 5.00 kg) 21 g / 10 minutes MX-004: manufactured by Mitsui Chemicals, Inc. Poly-4-methylpentene-1, MFR (260 ° C., 5.00 kg) 25 g / 10 min
Polybutene- 1 series resin PB8640M: Polybutene-1 manufactured by LYONDELBASELL, MFR (190 ° C., 21.18N) 28 g / 10 min Toughmer BL2000: Polybutene-1, MFR (190 ° C., 21.18 N) manufactured by Mitsui Chemicals, Inc. 1.0g / 10min
Liquid paraffin High Coal K-350: Liquid paraffin Moresco White P-350P manufactured by Kaneda Co., Ltd .: Liquid paraffin manufactured by MORESCO Co., Ltd.
Component for comparison FB3HAT: Polypropylene manufactured by Nippon Polypro Co., Ltd., grade for cast film, MFR (230 ° C., 21.18N) 7.5 g / 10 min DFD0118: Low density polyethylene manufactured by Nihon Unicar Co., Ltd., density 923 Kg / m ³ , MFR (190 ° C., 21.18 N) 2.4 g / 10 min

Measuring method (1) Cutting deviation amount (δ)
A rectangular film having side α (length 300 mm) and side β (length 220 mm), and side α parallel to the film length direction (MD direction) is used as a test piece, and the central portion of one side α A 3 mm long cut is made in the film, and the film is cut by pulling both corners on the side α side where the cut is made with a human hand (FIG. 1). The divergence between the reference line dropped perpendicularly to the other side α from the cut and the cutting line was measured, and the maximum value (unit: mm) was taken as the cutting deviation amount (δ). Three people conducted the above test three times, and the average value of nine times was taken. In addition, about the film which gave the knurling process or the laser processing, the test piece was created so that the edge part by which the knurling process or the laser processing was carried out might become said one side (alpha) in which a cut is made.

(2) End tensile breaking force in the MD direction (A)
A rectangular film having side A (length 60 mm) and side B (length 20 mm) and parallel to the film length direction (MD direction) is used as a test piece, and along both sides B Reinforcement with cellophane tape (Nichiban Co., Ltd. cello tape (registered trademark), grade name CT15-S) was performed at a width of 10 mm. A tensile test was performed by pulling one side A of the test piece with a tensile tester at a pulling speed of 200 mm / min, and the force (unit: N) when the test piece was broken was measured (FIG. 2). The test was performed 5 times and the average value was taken. For films that have been knurled or laser processed, a test piece is prepared so that the end of the knurled or laser processed is one of the sides A, and the knurled or laser processed side Side A was pulled.

(3) MD direction end tensile elongation (P)
The same tensile test as in the above test (2) was performed, the stroke amount S (unit: mm) when the test piece was broken was measured, and the elongation was calculated by the following equation. The test was performed 5 times and the average value was taken.
P = {S / (60-10 × 2)} × 100 (%)

(4) End tensile breaking force in the CD direction (b),
In the test of (2), the force (unit: N) at the time of breaking the test piece is the same as (2) except that the side A of the test piece is parallel to the lateral direction (CD direction) of the film. It was measured. The test was performed 5 times and the average value was taken.

(5) End tensile elongation in the CD direction (Q)
In the test of (3), the stroke amount S (unit: mm) when the test piece was broken in the same manner as (3) except that the side A of the test piece was parallel to the lateral direction (CD direction) of the film. Was measured and the elongation was calculated. The test was performed 5 times and the average value was taken.

(6) Cutability test in a storage box equipped with a cutting aid A width so as to cover the front and back 1 cm each of the front end of the lid of the box having the shape shown in FIG. 5 (basis weight of cardboard 400 g / m ² , 40 mm × 40 mm × 310 mm) A 2 cm × 310 mm long sandpaper (manufactured by Noritake Coated Abrasive Co., Ltd., water-resistant sandpaper, product name C947H) was folded and attached using a double-sided adhesive tape. The sandpaper counts used are # 320 and # 600. In this box, the wound film (300 mm wide, 20 m long film wound on a paper tube with a width of 305 mm, an inner diameter of 27 mm, and a wall thickness of 1.5 mm) is stored, the film is pulled out about 20 cm, and the lid With the closed, the cutting was attempted using the tip of the lid plate with the sandpaper. This trial was performed 10 times, and the number of times of cutting was expressed as a cutting rate (%).

In order for the film to be applicable to a box provided with sandpaper as a cutting aid, the cutting rate needs to be at least 80%, preferably at least 90%, more preferably 100%. Further, in consideration of the above-described detachability of the abrasive grains, it is considered that the cutting rate needs to be achieved with an abrasive grain size of # 320 or smaller.

(7) Tackiness test (rice ball packaging)
A cold rice ball (regular triangle shape, weight 100 g, side 7 cm, thickness 4 cm) at room temperature (25 ° C.) is wrapped with a film cut into a 30 cm square as shown in FIG. Twist to make a paper. The retainability of the packaged state was evaluated in the following three stages.
3: Paper is not scattered and held in the initial state.
2: Slightly unwind, but not so much that rice balls are exposed.
1: The paper roll is unwound and the onigiri is exposed.

(8) Transparency (haze value)
It measured according to JISK7105.

Examples 1-24 and Comparative Examples 1-12
Using each component of the compounding amount (part by mass) shown in Table 2, a thick film shown in Table 2 was manufactured using a T-die film forming apparatus manufactured by Nippon Steel Works, Ltd. under the conditions shown in Table 2. . The chill roll temperature was 25 ° C., the die outlet resin temperature was 290 ° C., and a vacuum chamber and an ear jet were used. Tests (1) to (8) were performed using the obtained film. The results are shown in Table 2.

As is apparent from Table 2, the film obtained according to the method of the present application is excellent in the cross-cut property. On the other hand, the film of Comparative Example 1 having a film thickness larger than the range of the present invention had no cross-cutting property. The films of Comparative Examples 2 to 4 using the resin composition in which the amount of the component (B) is larger than the range of the present invention are inferior in cross-cut property, and the film of Comparative Example 5 using the resin composition not containing the component (B). The film is inferior in tackiness. In Comparative Example 6, the discharge speed is halved in Example 19, and the cross-cut property is inferior. In Comparative Example 7, the lip opening is narrowed in Example 22, and the cross-cutting property is inferior. In Comparative Example 8, the discharge speed is halved in Example 22, and the cross-cut property is inferior. In Comparative Example 8, the film of Comparative Example 9 in which the film thickness was larger than the range of the present invention had no cross-cutting property. In Comparative Example 10, the air gap is increased in Example 23, and the cross-cut property is inferior. In addition, the manufacturing conditions of the comparative example 10 are the manufacturing conditions of four wrap (brand name) by Riken Technos, and correspond to the conventional method. In Example 18, in place of poly-4-methylpentene-1 as the component (A), both the comparative example 11 using polypropylene and the film of comparative example 12 using polyethylene are markedly long in the test for cutting deviation. Elongation occurred and had no cross-cutting property.

Examples 25-27 and Comparative Example 13
In Example 25, a knurling process with a width of 3 mm was applied to one of the end portions parallel to the length direction of the film of Example 1. The processing conditions were a presser foot amount of 0.2 mm, a processing width of 3 mm, and a processing speed of 400 m / min. In Example 26, knurling was performed in the same manner as in Example 25 except that the processing width was 0.6 mm. FIG. 3 shows a photograph of the film surface of the knurled portion of Example 25 taken. In Example 27, laser processing with a width of 3 mm was performed on one of the end portions parallel to the length direction of the film of Example 1. The processing conditions were that a carbon dioxide laser was used, the output was 1 W, the processing width was 3 mm, and the processing speed was 1000 mm / sec. FIG. 4 shows a photograph of the film surface of the laser processed part. In Comparative Example 13, knurling with a width of 3 mm was applied to one end of the Saran wrap (trade name) (Asahi Kasei Home Products Co., Ltd., wrap film of polyvinylidene chloride resin composition) parallel to the length direction. The processing conditions were the same as in Example 25. The following test (9) was performed on these films.

(9) Cutability test in storage box without cutting aids Wrapped in a box (cardboard basis weight 400 g / m ² , 40 mm x 40 mm x 310 mm) with no cutting aids such as saw teeth, as shown in Fig. 5 Box (with a width of 300 mm and a length of 20 m, wrapped in a paper tube with a width of 305 mm, an inner diameter of 27 mm, and a wall thickness of 1.5 mm), the film is pulled out about 20 cm, and the lid is closed. Cutting was attempted 10 times using the ridge line portion between the front plate and the bottom plate, and the number of cuts was expressed as a cutting rate (%). In addition, the same test was done also about the film of Example 1 which has not performed knurling or laser processing. The results are shown in Table 3.

Comparative Examples 14-17
Tests (1) to (8) were performed using the following commercially available packaging films. The results are shown in Table 4.
Comparative Example 14: Kurewrap (trade name) (manufactured by Kureha Corporation, a wrap film of a polyvinylidene chloride resin composition)
Comparative Example 15: Saran Wrap (trade name) (made by Asahi Kasei Home Products Co., Ltd., wrap film of polyvinylidene chloride resin composition)
Comparative Example 16: Hitachi wrap (trade name) (manufactured by Hitachi Chemical Filtech Co., Ltd., a wrap film of a polyvinyl chloride resin composition)
Comparative Example 17: Polywrap (trade name) (manufactured by Ube Film Co., Ltd., polyethylene wrap film)

In addition, about the test (6), it tested about the sandpaper which has six types of counts (abrasive grain size) shown in Table 4. The same test was performed on the film of Example 1.

Claims (5)

(A) 100 parts by mass of polymethylpentene-1 resin and (B) 0.5 to 60 parts by mass of polybutene-1 resin and / or 0.1 to 20 parts by weight of liquid paraffin, provided that the total amount of component (B) Including extruding a polymethylpentene-1-based resin composition containing no more than 75 parts by weight using a T die to obtain a packaging film having a film thickness of 3 to 30 μm. Lip opening R (unit μm), film thickness t (unit μm), discharge speed E (unit cm ³ / hr) per 1 cm die width of resin composition extruded from the die, and air gap A (unit cm) Is the following formula 1:
15 ≦ (1 / t − 1 / R) · (E / At ) × 100 ≦ 900 Formula 1
The manufacturing method of the film for packaging characterized by satisfy | filling. A packaging film obtained by the method according to claim 1, wherein the packaging film satisfies the following (1) to (3):
(1) The cutting deviation amount (δ) in the film cutting test is 10 mm or less.
(2) The end tensile elongation (P) in the length direction of the film is 120% or less, and (3) the end tensile elongation (P) in the length direction of the film and the end tensile elongation in the lateral direction (Q ) And the ratio P / Q is 0.25 or less,
Here, the cutting deviation amount (δ) is a test piece of a rectangular film having side α (length 300 mm) and side β (length 220 mm) and side α is parallel to the length direction of the film, Insert a 3 mm long incision into the center of one side α, and cut the film by pulling both corners on the side α side where the incision was made, and from the notch to the other side α The maximum value (unit: mm) of the deviation from the vertical reference line;
The end tensile elongation (P) in the length direction of the film is a rectangular film having side A (length 60 mm) and side B (length 20 mm), and side A is parallel to the length direction of the film. The elongation at break of the test piece when the test piece is pulled at one of the sides A of the test piece at a pulling speed of 200 mm / min;
The lateral end tensile elongation (Q) of the film is determined when the test piece breaks when the tensile test is performed in the same manner as in the above (P) except that the side A of the test piece is parallel to the horizontal direction of the film. Growth. The wrapping film according to claim 2, wherein knurling and / or laser processing having a width of 0.1 to 10 mm is applied to at least one of the end portions parallel to the length direction of the film. A packaging film product, wherein the wound film of the packaging film according to claim 2 or 3 is stored in a storage box without a saw-tooth cutting aid. 4. A packaging film product, wherein the wound film of the packaging film according to claim 2 or 3 is housed in a housing box having sandpaper having an abrasive particle size of # 320 or smaller.