JP2022031147A - Vinylidene chloride resin wrap film - Google Patents

Abstract

To provide a vinylidene chloride resin wrap film that does not cause tear troubles even when pulled by 1% to 10% in a TD direction and prevents smell of the content from leaking out.SOLUTION: The vinylidene chloride resin wrap film is a wrap film that contains vinylidene chloride resin, where the size of the crystal long period is 8.2 nm or more and 14.5 nm or less when pulled by 10% in a TD direction.SELECTED DRAWING: None

Description

The present invention relates to a vinylidene chloride resin wrap film.

Vinylidene chloride-based resins are used as wrap films and the like because they have excellent properties such as transparency, water resistance, and gas barrier properties. In recent years, with the spread of microwave ovens, the range of foods wrapped in plastic wrap has been increased. Range-up means cooking refrigerated or frozen foods by heating them in a microwave oven.

For example, Patent Documents 1 and 2 disclose techniques relating to the property of being easy to cut in the width direction in addition to the property of being hard to tear in the flow direction of the film.

Japanese Patent No. 5501791 International Publication No. 2016/189987 Pamphlet

When packaging foods and containers using plastic wrap, it is common practice to store tableware and containers on top of the state in which the tableware and containers are wrapped with plastic wrap for storage. At this time, the wrap film is in a state of being pulled by about 1%, and the film strength when pulled by about 1% in the TD direction, which is the direction perpendicular to the direction in which the tear of the film propagates, is particularly important. Having sufficient film strength when pulled in the TD direction by about 1% makes it possible to further stack the tableware and the container on the state in which the tableware and the container are wrapped with the wrap film. Further, if a crystal higher-order structure can be formed when pulled in the TD direction by about 1%, the film strength can be increased, the gas barrier property can be improved, and the permeation of molecules that cause odors can be prevented. be able to.
Further, when wrapping vegetables or the like with a wrap film, it is generally performed to wrap the wrap film with the wrap film while pulling the film moderately in order to prevent the wrap film from wrinkling. At this time, the wrap film is in a state of being pulled by about 10%, and the film strength when pulled by about 10% in the TD direction, which is the direction perpendicular to the direction in which the tear of the film propagates, is particularly important. By having sufficient film strength when pulled in the TD direction by about 10%, when wrapping vegetables or the like with a wrap film, it is possible to wrap vegetables neatly without wrinkles. Further, the state in which the wrap film is pulled by 10% imitates the state in which when wrapping vegetables and the like, the wrap film is in close contact with the wrap film so as not to cause wrinkles. By forming a large crystal high-order structure in this state, it is possible to prevent the film from tearing and prevent odor leakage while maintaining the freshness of vegetables and the like.
However, depending on the crystalline state of the wrap film, tearing trouble may occur when the wrap film is pulled by about 1% to 10% in the TD direction, and the tearing of the film generated from the edge of the film may propagate to the entire film. .. Further, depending on the crystalline state of the wrap film, when the wrap film is pulled by about 1% to 10% in the TD direction, the gas barrier property may be lowered, and a problem may occur in which the odor of a package such as food leaks out.

The present invention has been made in view of the above problems, and even when the film is pulled in the TD direction by about 1% to 10%, no tearing trouble occurs and no odor of the contents leaks out. It is an object of the present invention to provide a vinylidene resin wrap film.

As a result of diligent studies to solve the above problems, the present inventors have found that a wrap film containing a vinylidene chloride resin has a crystal length period of 8 when pulled in the TD direction by 10%. It was found that when the thickness was 2 nm or more and 14.5 nm or less, no tearing trouble occurred and the odor of the contents did not leak when the film was pulled in the TD direction by about 10%.

That is, the present invention is as follows.
[1]
A wrap film containing a vinylidene chloride resin, wherein the size of the crystal length cycle when pulled by 10% in the TD direction is 8.2 nm or more and 14.5 nm or less.
[2]
The vinylidene chloride-based resin wrap film according to the above [1], wherein the size of the crystal length period when pulled by 1% in the TD direction is 7.5 nm or more and 13.5 nm or less.
[3]
The vinylidene chloride-based resin wrap film according to the above [1] or [2], which has a thickness of 6 to 18 μm.
[4]
The above [1] to [3], wherein the vinylidene chloride-based resin contains a copolymer composed of a constituent unit derived from vinylidene chloride of 85 to 97% by mass and a constituent unit derived from vinyl chloride of 15 to 3% by mass. The vinylidene chloride resin wrap film according to any one.
[5]
The vinylidene chloride-based resin wrap film according to any one of the above [1] to [4] and a winding core are included.
A wound body in which the vinylidene chloride resin wrap film is wound around the core.

According to the present invention, a vinylidene chloride-based resin wrap film can be obtained that does not cause tearing trouble when pulled in the TD direction by about 10% and does not leak the odor of the contents.

It is a schematic diagram of the apparatus used in the film forming process of this invention. This is an example of the use form of the film of the present invention.

Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. The present invention is not limited to the following embodiments, and can be variously modified and implemented within the scope of the gist thereof.

[Vinylidene chloride resin wrap film]
The vinylidene chloride-based resin wrap film of the present embodiment (hereinafter, also simply referred to as “wrap film”) is a wrap film containing a vinylidene chloride-based resin and has a crystal length cycle when pulled in the TD direction by 10%. The size is 8.2 nm or more and 14.5 nm or less. By having such a structure, the vinylidene chloride resin wrap film of the present embodiment does not cause tearing trouble when pulled in the TD direction by about 10%, and the odor of the contents does not leak out. .. The reason for this is not clear, but it can be inferred as follows.
Since the size of the crystal length period when pulled by 10% in the TD direction is as large as 8.2 nm or more and 14.5 nm or less, the propagation of tears in the film can be stopped by the large crystal high-order structure. Inferred. At this time, since the wrap film is cut in the TD direction along the saw blade, the propagation of tears proceeds in the MD direction, which is the vertical direction thereof. Therefore, the size of the crystal length period when pulled in the TD direction is important for stopping the propagation of film tears. In addition, it is presumed that the large crystal high-order structure can prevent molecules that cause odor from penetrating the film. The above reason is an estimation and is not limited to this.
The state in which the wrap film is pulled by 10% imitates the state in which when wrapping vegetables and the like, the wrap film is in close contact with the wrap film so as not to cause wrinkles. By forming a large crystal high-order structure in this state, it is possible to prevent the film from tearing and prevent odor leakage while maintaining the freshness of vegetables and the like.

The vinylidene chloride resin wrap film of the present embodiment has a crystal length period of 8.2 nm or more and 14.5 nm or less, and 8.7 nm or more and 14.5 nm or less when pulled by 10% in the TD direction. It is more preferable, it is more preferably 9.2 nm or more and 14.5 nm or less, further preferably 9.7 nm or more and 14.5 nm or less, and even more preferably 11.0 nm or more and 14.5 nm or less. It is particularly preferably 12.5 nm or more and 14.5 nm or less. When the size of the crystal length period when pulled 10% in the TD direction is 14.5 nm or less, sufficient crystallization of the film tends to make it difficult to break when the film is pulled 10%. When it is 8.2 nm or more, when the film is pulled by 10%, the effect of suppressing the breakage of the film by crystals tends to be obtained.

Further, in the vinylidene chloride resin wrap film of the present embodiment, the size of the crystal length period when pulled by 1% in the TD direction is preferably 7.5 nm or more and 13.5 nm or less, preferably 8.0 nm or more and 13 It is more preferably 5.5 nm or less, further preferably 8.5 nm or more and 13.5 nm or less, further preferably 9.0 nm or more and 13.5 nm or less, and 9.4 nm or more and 13.5 nm or less. It is even more preferably present, and particularly preferably 11.3 nm or more and 13.5 nm or less. When the size of the crystal length period when pulled by 1% in the TD direction is 13.5 nm or less, sufficient crystallization of the film tends to make it difficult to break when the film is pulled by 1%. When it is 7.5 nm or more, when the film is pulled by 1%, the effect of suppressing the breakage of the film by crystals tends to be obtained.
The state in which the wrap film is pulled by 1% imitates the state in which the plate is placed on the wrap film after wrapping the plate while pulling the wrap film. By forming a large crystal high-order structure in this state, it is possible to prevent the film from tearing and prevent odor leakage while maintaining the freshness of vegetables and the like.

The crystal length period when the wrap film is pulled can be adjusted by changing the distance (hot distance) from the die mouth to the cold water tank. The distance (hot distance) from the die mouth to the cold water tank is not particularly limited, but is preferably 40 to 80 mm.

The crystal length period when the wrap film is pulled can be obtained by measuring by a stretched in-situ small-angle X-ray scattering method. In the measurement, the wrap film is measured by the transmission method.
The scattering profile by stretched in-situ small-angle X-ray scattering is obtained by irradiating the sample with X-rays and detecting the position and intensity of the scattered X-rays with a detector. Then, the scattering profile is obtained by plotting the measured scattering intensity I (q) with respect to the scattering vector q. This scattering profile contains information that reflects the microstructure of the sample. Specifically, it includes information such as the average particle size of the particles and aggregates in the sample and the distance between the average particles. Therefore, this information can be obtained by analyzing the scattering profile. In this scattering profile, the scattering angle on the horizontal axis is converted into the period length using Bragg's equation, and the peak position of the scattering intensity is obtained as the long period of scattering (crystal length period L).
The synchrotron radiation is light emitted by the synchrotron along with the electron synchrotron. Synchrotron radiation contains electromagnetic waves of various wavelengths having characteristics such as monochromatic, high brightness, and high directivity, and also contains monochromatic, high brightness, and highly directional X-rays in the X-ray region. .. Therefore, by using this X-ray, it is possible to acquire a scattering profile containing more information than in the case of using a normal X-ray using an X-ray tube or the like.
Such synchrotron radiation is, for example, SPring-8 of the High Brightness Photon Science Research Center, PF Ring of the High Energy Accelerator Research Organization, UVSOR of the Institute of Molecular Science, HiSOR of the Hiroshima University Synchrotron Radiation Research Center, etc. It can be used in synchrotron radiation facilities.

The thickness of the wrap film of the present embodiment is preferably 6 to 18 μm, more preferably 9 to 12 μm. When the thickness of the wrap film is 6 μm or more, the tensile strength of the film is high, and there is a tendency that the film breakage during use can be suppressed. In addition, there is no significant decrease in tear strength, and when the film is pulled out from the winding body and when the end of the film rewound into the cosmetic box is picked out, the film is cut from the end cut by the cutting blade attached to the cosmetic box. There is a tendency to reduce the trouble of tearing. On the other hand, when the thickness of the wrap film is 18 μm or less, the force required to cut the film with the film cutting blade can be reduced, the cutability is good, and the film easily fits the shape of the container, so that it can be put into the container. Adhesion tends to improve. That is, the thickness of the wrap film tends to be adjusted to a specific range from the viewpoint of suppressing troubles of film breakage, cutting property, and balance of adhesion. In particular, a wrap film having a thickness of 6 to 18 μm does not significantly reduce the tear strength, but is not sufficient at all, and the film tends to have tear troubles, so that the effect of the present invention becomes remarkable. The thickness of the wrap film can be measured according to the method described in Examples described later.

<Vinylidene chloride resin>
The vinylidene chloride-based resin wrap film of the present embodiment contains a vinylidene chloride-based resin.
The vinylidene chloride-based resin used in the present embodiment is not particularly limited as long as it contains a structural unit derived from vinylidene chloride, and in addition to the structural unit derived from vinylidene chloride, for example, acrylic acids such as vinyl chloride, methyl acrylate, and butyl acrylate. Esters; Metaacrylic acid esters such as methyl methacrylate and butyl methacrylate; Acrylonitrile; Vinylidene chloride and the like, which may be one or more copolymerized with vinylidene chloride.

The weight average molecular weight (Mw) of the vinylidene chloride copolymer is preferably 80.000 to 200,000, more preferably 90,000 to 180,000, still more preferably 100,000 to 170,000. be. When the weight average molecular weight (Mw) is within the above range, the mechanical strength of the wrap film tends to be further improved. The vinylidene chloride-based resin having a weight average molecular weight within the above range can be obtained, for example, by controlling the charging ratio of the vinylidene chloride monomer and the vinyl chloride monomer, the amount of the polymerization initiator, or the polymerization temperature. In this embodiment, the weight average molecular weight (Mw) can be determined by gel permeation chromatography (GPC method) using a standard polystyrene calibration curve.

When the vinylidene chloride-based resin is a copolymer resin, the ratio of the constituent units derived from vinylidene chloride is not particularly limited, but those containing 72 to 93 mol% of the constituent units derived from vinylidene chloride are preferable, and those containing 81 to 90 mol% are preferable. More preferred. When the constituent unit derived from vinylidene chloride is 72 mol% or more, the glass transition temperature of the vinylidene chloride resin is low and the film becomes soft, so that the film tearing tends to be reduced even when used in a low temperature environment such as winter. .. On the other hand, when the constituent unit derived from vinylidene chloride is 93 mol% or less, there is a tendency that a large increase in crystallinity can be suppressed and a deterioration in moldability during film stretching can be suppressed.
In particular, a wrap film made of a vinylidene chloride-based resin containing 72 mol% or more of vinylidene chloride-derived constituent units receives heat to form and grow microcrystals when stored and distributed at high temperatures such as in summer, and is physically physical. Deterioration is likely to occur, and as a result, tearing troubles are likely to occur when the film is used, so that the effect of the present invention becomes more remarkable.

When the vinylidene chloride-based resin is a copolymer resin, the vinylidene chloride-based resin is a copolymer composed of 85 to 97% by mass of a constituent unit derived from vinylidene chloride and 15 to 3% by mass of a constituent unit derived from vinyl chloride. It is preferable to include it. By setting the vinylidene chloride monomer ratio to 85% by mass or more, the oxygen / water barrier property and the film-cutting property tend to be further improved, and the vinylidene chloride monomer ratio should be 97% by mass or less. Therefore, there is a tendency that the workability can be further improved.

The content of the structural unit derived from vinylidene chloride and the structural unit derived from vinyl chloride is not particularly limited, but can be measured by using, for example, a highly decomposed proton nuclear magnetic resonance measuring apparatus. More specifically, the reprecipitated filtrate of the wrap film is obtained according to the following procedure.
0.5 g of the sample is dissolved in 10 ml of THF (tetrahydrofuran), about 30 ml of methanol is added to precipitate the resin component, and then filtration is performed to separate and dry the precipitate.
The reprecipitated filtrate thus obtained is vacuum dried, and a solution prepared by dissolving 5% by mass in deuterated tetrahydrofuran is subjected to 1 H-NMR measurement in a measurement atmosphere of 23 ± 2 ° C. and 50 ± 10% RH (number of integrations). : 512 times). The building blocks derived from vinylidene chloride and the building blocks derived from vinyl chloride are calculated using a unique chemical shift based on tetramethylsilane in the obtained spectrum.

Hereinafter, the structural unit derived from vinylidene chloride (-CH ₂ -CCl _{2-) is referred to as A, and the structural unit derived from vinyl chloride (-CH 2 -} CHCl-) is referred to as B, and signals 1, 2, and appearing on the spectrum are expressed as B. 3 is attributed as follows.
-Signal 1 (about 5.2 to 4.5 ppm) is assigned to the CH signal of B (the methine (CH) group of the constituent unit derived from vinyl chloride).
-Signal 2 (about 4.2 to 3.8 ppm) is assigned to the CH ₂ signal (methylene (CH ₂ ) group of the building block derived from vinylidene chloride) of A on one side of AA.
-Signal 3 (about 3.5-2.8 ppm) is assigned to the CH ₂ signal (methylene (CH ₂ ) group of the building block derived from vinylidene chloride) of A in both AB and BA.

From the spectral area value of these signals (the area of the signal in the NMR spectrum), the mole fraction of the constituent unit is obtained. In addition, each mole fraction is expressed as follows.
-Mole fraction of A (mol%): P (A)
-Mole fraction of B (mol%): P (B)

From the area values of signals 1, 2, and 3 (the area of the peak in the NMR spectrum) assigned as described above, the integrated value of the signal on the spectrum is assigned as follows.
-Integral value of signal 1 (about 5.2 to 4.5 ppm) for 1H of B-Integral value of signal 2 (about 4.2 to 3.8 ppm) for 1H2 of A-Signal 3 (about 3) Integral value of .5 to 2.8 ppm) for 1H4 of A

Calculate each mole fraction using the following equation.
・ P (A) + P (B) = 100

P (A) and P (B) are calculated by the following equations.
P (B): P (A) = Integral value of signal 1: (Integral value of signal 2 + Integral value of signal 3/2) / 2
・ P (A) = 100-P (B)

The molecular weight of A, which is a structural unit derived from vinylidene chloride (-CH ₂ -CCl _{2-), is 97.0, and the molecular weight of B, which is a structural unit derived from vinyl chloride (-CH 2 -} CHCl-), is 62.5. , Calculate each mass fraction using the following equation. In addition, each mass fraction is expressed as follows.
-Mass fraction of A (mass percent): Q (A)
-Mass fraction of B (mass percent): Q (B)
Q (A) = (P (A) x 97.0) / (P (A) x 97.0 + P (B) x 62.5) x 100
・ Q (B) = 100-Q (A)

The content of the vinylidene chloride-based resin is preferably 77 to 94% by mass, more preferably 85 to 94% by mass, based on the total amount of the wrap film. When the content of the vinylidene chloride-based resin is within the above range, it is possible to suppress the film from being easily stretched due to the plasticizing effect of the additive or the like, and the cuttability of the film tends to be further improved.

The method of measuring the content of each component in the wrap film differs depending on the analysis target. For example, the content of the vinylidene chloride-based resin can be obtained by vacuum-drying the reprecipitated filtrate of the wrap film and measuring the mass. On the other hand, the content of the epoxidized vegetable oil can be obtained by, for example, gel permeation chromatography analysis of the reprecipitation filtrate of the wrap film, or a method using NMR. Further, the content of the citric acid ester and the dibasic acid ester can be obtained by extracting the additive from the wrap film using an organic solvent such as acetone and performing gas chromatography analysis.

The vinylidene chloride-based resin wrap film of the present embodiment may contain various additives in addition to the vinylidene chloride-based resin, if necessary. The additive is not particularly limited, and examples thereof include known stabilizers such as epoxidized vegetable oils, and known plasticizers such as citric acid ester and dibasic acid ester.

<Epoxidized vegetable oil>
The vinylidene chloride-based resin wrap film of the present embodiment preferably contains an epoxidized vegetable oil from the viewpoint of suppressing a change in the color tone of the wrap film. The epoxidized vegetable oil also acts as a stabilizer for extrusion of vinylidene chloride resin.

The epoxidized vegetable oil is not particularly limited, but generally includes those produced by epoxidizing edible oils and fats. Specific examples thereof include epoxidized soybean oil (ESO) and epoxidized flaxseed oil. Among these, when the wrap film is stored at a high temperature, deterioration of the pullability of the film from the cosmetic box can be suppressed. ESO is preferred because of the tendency.

When the wrap film of the present embodiment contains an epoxidized vegetable oil, the content thereof is not particularly limited, but from the viewpoint of suppressing the color change of the wrap film and preventing stickiness due to bleeding, the vinylidene chloride resin is 0. 5 to 3% by mass is preferable, and 1 to 2% by mass is more preferable.

The method for measuring the epoxidized vegetable oil content using NMR follows the following procedure.
A 50 mg sample is weighed, dissolved in a deuterated solvent (solvent: deuterated THF, internal standard: dimethyl terephthalate, volume: 0.7 ml), and measured by 400 MHz proton NMR (integration number: 512 times). The ratio of the integrated value of 2.23 to 2.33 ppm to the integrated value of 8.05 to 8.11 ppm is used as the integral ratio, and the quantitative value is calculated by the absolute calibration curve method.
Integral ratio = Integral value (2.23 to 2.33 ppm) / Integral value (8.05 to 8.11 ppm)

The method for measuring the epoxidized vegetable oil content using gel permeation chromatography follows the following procedure.
Weigh 3 g of the sample into a tall beaker, add 30 ml of THF, stir with a stirrer, and heat (50 ° C. x 4 min) to completely dissolve.
Methanol (170 ml) is slowly added dropwise and reprecipitated while stirring with a stirrer. After dropping the entire amount of methanol, suction filter it through a glass filter. After concentrating the filtrate and drying it in vacuum, put it in a 10 ml volumetric flask and measure it with chloroform. The chloroform solution is filtered through a syringe filter (material PTFE, pore size 0.45 μm) and analyzed by GPC. For the standard sample, weigh the ESO into a volumetric flask and prepare 3 levels of the volumetric flask with chloroform. Filter with a syringe filter in the same way as the sample and perform GPC analysis. GPC analysis and standard sample concentration are plotted to create a calibration curve.
The GPC area of the sample is applied to the calibration curve, the concentration is calculated, and the ESO quantitative value is calculated.

<Citric acid ester and dibasic acid ester>
The wrap film of the present embodiment preferably contains at least one compound selected from the group consisting of citric acid ester and dibasic acid ester from the viewpoint of molding processability and the like.

The citric acid ester used in the wrap film of the present embodiment is not particularly limited, and examples thereof include triethyl citrate, tributyl citrate, triethyl acetyl citrate, ATBC, and tri-n- (2-ethylhexyl) acetyl citrate. .. Among these, ATBC is preferable because it has a high plasticizing effect on vinylidene chloride-based resin and tends to sufficiently plasticize the resin even in a small amount to improve molding processability.

The dibasic acid ester contained in the wrap film of the present embodiment is not particularly limited, but is an adipic acid ester system such as dibutyl adipate, din-hexyl adipate, di-2-ethylhexyl adipate, and dioctyl adipate; Examples include adipic acid esters such as di-2-ethylhexyl azelaic acid and octyl adipic acid; sebacic acid esters such as dibutyl sebacate (DBS) and di-2-ethylhexyl sebacate. Among these, DBS is preferable because it has a high plasticizing effect on vinylidene chloride-based resin and tends to sufficiently plasticize the resin even in a small amount to improve molding processability.

The total content of the citric acid ester and the dibasic acid ester is not particularly limited, but from the viewpoint of imparting better molding processability and preventing excessive adhesion of the wrap film when the additive content is high, chloride is used. 3 to 8% by mass is preferable, 3 to 7% by mass is more preferable, 3 to 5% by mass is more preferable, and 3.5 to 5% by mass is particularly preferable with respect to the vinylidene resin.

In particular, when the vinylidene chloride resin wrap film contains 3% by mass or more of a citric acid ester or a dibasic acid ester, the mobility of the molecular chain of the vinylidene chloride resin becomes high, so that the formation and growth of microcrystals, etc. Rearrangement is likely to occur, physical deterioration is likely to occur when exposed to high temperatures, and the film is likely to stretch, making it difficult for the cutting blade to bite into the film, which tends to reduce cutability. The effect of is more remarkable.

<Acetylated fatty acid glyceride>
The wrap film of the present embodiment may contain an acetylated fatty acid glyceride as a plasticizer. The acetylated fatty acid glyceride is not particularly limited, and for example, acetylated caprylic acid glyceride, acetylated capric acid glyceride, acetylated lauric acid glyceride, acetylated myristic acid glyceride, acetylated palm kernel oil glyceride, and acetylated coconut oil glyceride. , Acetylated castor oil glyceride, acetylated hardened castor oil glyceride.

The acetylated fatty acid glyceride may be any of acetylated monoglyceride of fatty acid, acetylated diglyceride of fatty acid, and acetylated triglyceride of fatty acid. For example, the acetylated lauric acid glyceride includes acetylated monoglyceride of lauric acid, acetylated diglyceride of lauric acid (DALG: diacetyllauroylglycerol), and acetylated triglyceride of lauric acid. Of these, acetylated lauric acid glyceride is preferable, and acetylated diglyceride of lauric acid is more preferable.

The content of the acetylated fatty acid glyceride is preferably 3 to 8% by mass, more preferably 3.5 to 7% by mass, still more preferably 4 to 6% by mass, based on the total amount of the wrap film. .. When the content of the acetylated fatty acid glyceride is within the above range, the molding processability tends to be further improved. The method of measuring the content of each component from the wrap film differs depending on the analysis target. The content of the acetylated fatty acid glyceride can be obtained by extracting the additive from the wrap film using an organic solvent such as acetone and performing gas chromatography analysis.

The total content of at least one compound selected from the group consisting of citric acid ester, dibasic acid ester, and acetylated fatty acid glyceride is preferably 3 to 8% by mass, more preferably, based on the total amount of the wrap film. Is 3.5 to 7% by mass, more preferably 4 to 6% by mass. When the total content of citric acid ester, dibasic acid ester, and acetylated fatty acid glyceride is within the above range, the molding processability is further improved, and the excess due to bleeding of the wrap film when the epoxidized vegetable oil is high is contained. Stickiness tends to be suppressed.

<Other formulations>
The vinylidene chloride resin wrap film of the present embodiment is a compound other than the epoxidized vegetable oil, citric acid ester, dibasic acid ester, and acetylated fatty acid glyceride (hereinafter referred to as "other compound"), for example, plasticizer. Agents, stabilizers, weather resistance improvers, colorants such as dyes or pigments, antifogging agents, antibacterial agents, lubricants, nucleating agents, oligomers such as polyester, polymers such as MBS (methylmethacrylate-butadiene-styrene copolymer) Etc. may be contained.

The plasticizer is not particularly limited, and specific examples thereof include dimethyl phthalate, diethyl phthalate, dioctyl phthalate, glycerin, glycerin ester, wax, liquid paraffin, and phosphoric acid ester.

The stabilizer is not particularly limited, but specifically, 2,5-t-butylhydroquinone, 2,6-di-t-butyl-p-cresol, and 4,4'-thiobis- (6-t). -Butylphenol), 2,2'-methylene-bis- (4-methyl-6-t-butylphenol), octadecyl-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl)
Antioxidants such as bropionate and 4,4'-thiobis- (6-t-butylphenol); laurate, myristate, palmitate, stearate, isostearate, oleate, lysinolate. , 2-Ethyl-hexylate, isodecanoate, neodecanoate, and heat stabilizers such as calcium benzoate.

The weather resistance improving agent is not particularly limited, but specifically, ethylene-2-cyano-3,3'-diphenylacrylate, 2- (2'-hydroxy-5'-methylphenyl) benzolithriazole, and the like. 2- (2'-Hydroxy-3'-t-butyl-5'-methylphenyl) 5-chlorobenzotriazole, 2-hydroxy-4-methoxybenzophenone, and 2,2'-dihydroxy-4-methoxybenzophenone, etc. Examples include UV absorbers.

The colorant such as the dye or the pigment is not particularly limited, and specific examples thereof include carbon black, phthalocyanine, quinacridone, indoline, an azo pigment, and red iron oxide.

The antifogging agent is not particularly limited, and specific examples thereof include glycerin fatty acid ester, sorbitan fatty acid ester, polyoxyethylene fatty acid alcohol ether, polyoxyethylene glycerin fatty acid ester, and polyoxyethylene sorbitan fatty acid ester. ..

The antibacterial agent is not particularly limited, and specific examples thereof include a silver-based inorganic antibacterial agent.

The lubricant is not particularly limited, but specifically, a fatty acid hydrocarbon-based lubricant such as ethylene bissteroamide, butyl stearate, polyethylene wax, paraffin wax, carnauba wax, myristyl myristate, and stearyl stearate, and higher fatty acids. Examples thereof include lubricants, fatty acid amide-based lubricants, and fatty acid ester lubricants.

The nucleating agent is not particularly limited, and specific examples thereof include a phosphoric acid ester metal salt and the like.

The content of the other compound is preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably 1% by mass or less, and particularly preferably 0.1% by mass or less with respect to the wrap film. Is.

[Roller]
The winding body of the present embodiment includes the above-mentioned vinylidene chloride-based resin wrap film and the winding core, and the vinylidene chloride-based resin wrap film is wound around the winding core. The wound body can be manufactured, for example, according to the manufacturing method described later.

[Manufacturing method of wrap film]
The method for producing the wrap film of the present embodiment is not particularly limited, but is at least one selected from the group consisting of, for example, a vinylidene chloride resin, an epoxidized vegetable oil, a citric acid ester, a dibasic acid ester, and an acetylated fatty acid glyceride. Examples thereof include a step of melt-extruding a composition containing the above compound to form a film, and a step of stretching the obtained film in the MD direction and the TD direction. The details will be described below.

(Mixing process)
FIG. 1 shows a schematic view of an example of a wrap film manufacturing process. First, a vinylidene chloride resin and at least one compound selected from the group consisting of epoxidized vegetable oil, citric acid ester and dibasic acid ester and acetylated fatty acid glyceride are mixed with a mixer to obtain a composition. At this time, various additives may be mixed as needed. The mixer is not particularly limited, but for example, a ribbon blender, a Henschel mixer, or the like can be used. The obtained composition is preferably aged for about 1 to 30 hours and used in the next step.

(Melting extrusion process)
Next, the obtained composition is melted by an extruder 1 and a tubular film is extruded from the die opening 3 of the die 2 to form a sock 4 (also referred to as a pile).

(Cooling process)
The sock liquid 5 is injected into the inside of the sock 4, and the outside of the sock 4 is brought into contact with the cold water of the cold water tank 6. As a result, the sock 4 is cooled from both the inside and the outside, and the film constituting the sock 4 is solidified. The solidified sock 4 is folded by the first pinch roll 7 to form the parison 8. At this time, the distance from the die mouth 3 to the cold water tank 6 is called a hot distance. By adjusting the distance of this hot distance, it is possible to adjust the crystal length period when the wrap film is pulled.

(Stretching process)
Subsequently, air is injected into the inside of the parison 8 to open the parison 8 and form an annular film. At this time, the sock liquid 5 applied to the portion corresponding to the inner surface of the sock 4 exerts an effect as an opening agent for the parison 8. The parison 8 is then reheated with warm water to a temperature suitable for stretching in the open state. The hot water adhering to the outside of the parison 8 is squeezed by the second pinch roll 9.

Air is injected into the inside of the parison 8 heated to an appropriate temperature as described above to form the bubble 10. When this air pushes the parison from the inside, the film is stretched and a stretched film is obtained. Stretching of the film in the TD direction is mainly performed by the amount of air, and stretching of the film in the MD direction is performed by applying tension in the flow direction of the film using a second pinch roll 9 and a third pinch roll 11 or the like. Will be done.

The process from the first pinch roll 7 to the third pinch roll 11 is called a stretching step. Since the stretchability of the parison 8 is improved when the stretching speed is slowed down, in the conventional method for producing a wrap film, the stretching speed in the MD direction is adjusted to 0.08 times / s or less, and the stretching speed in the TD direction is set to 3. It was adjusted to 0 times / s or less. On the other hand, in the method for producing a wrap film of the present embodiment in which the crystallization start temperature is controlled to 40 to 60 ° C., the stretching ratio in the MD direction and the TD direction and the stretching speed in the MD direction and the TD direction are predetermined. It is preferable to adjust to the range.

Specifically, the stretching ratios in the MD direction and the TD direction in the stretching step of the present embodiment are independently, preferably 4 to 6 times, and more preferably 4.5 to 5.5. Here, the stretching ratio in the MD direction refers to the stretching ratio of the parison 8 stretched in the MD direction. For example, in FIG. 1, the ratio of the rotation speed of the third pinch roll 11 to the rotation speed of the first pinch roll 7 is used. Can be calculated. The stretching ratio in the TD direction refers to the stretching ratio of the parison 8 stretched in the TD direction. For example, in FIG. 1, it is calculated by the ratio of the width length of the double ply film 12 to the width length of the parison 8. Can be done. The stretching ratio in the MD direction can be adjusted by, for example, the rotation speed ratio of the first pinch roll 7 and the third pinch roll 11, and the stretching ratio in the TD direction is, for example, the stretching temperature of the parison 8 or the size of the bubble 10. It can be adjusted with.

The stretching speed in the MD direction in the stretching step of the present embodiment is preferably 0.09 to 0.12 times / s. The average stretching speed in the MD direction refers to the stretching ratio in the MD direction with respect to the time during which the parison passes between the first pinch roll 7 and the third pinch roll 11. For example, in FIG. 1, the first pinch roll 7 It can be calculated by the rotation speed, the rotation speed of the third pinch roll 11, and the time required for the parison 8 to pass between the first pinch roll 7 and the third pinch roll 11. The stretching speed in the MD direction can be adjusted by, for example, the rotation speed of the first pinch roll 7 or the third pinch roll 11 or the distance between the first pinch roll 7 and the third pinch roll 11.

Further, the stretching speed in the TD direction in the stretching step of the present embodiment is preferably 3.1 to 4.0 times / s. The average stretching speed in the TD direction refers to the stretching ratio in the TD direction with respect to the time required for the parison 8 to expand to the bubble 10, for example, in FIG. 1, it was measured using still images of the parison 8 and the bubble 10. It can be calculated from the time required for stretching in the TD direction calculated from the stretching length and the rotation speed of the third pinch roll 11, and the stretching ratio in the TD direction. The stretching speed in the TD direction can be adjusted by, for example, the rotation speed of the third pinch roll 11.

The stretching temperature is not particularly limited, but is preferably 25 to 45 ° C.

After the stretching step, the stretched film is folded by the third pinch roll 11 to become a double ply film 12. The double ply film 12 is wound by the winding roll 13.

(Mitigation process)
In the method for producing a wrap film of the present embodiment, it is preferable to have a relaxation step for relaxing the wrap film immediately after stretching. A relatively commonly used relaxation method in the method for producing a wrap film is to relax the film by using heat from an infrared heater or the like after stretching. However, in the present embodiment, instead of this relaxation step, it is preferable to use a method of relaxing the stretched film by slowing the rotation speed of the take-up roll 13 from the third pinch roll 11.

The relaxation ratio in the relaxation step using the third pinch roll 11 and the take-up roll 13 is preferably 7 to 15%, more preferably 9 to 13%. When the relaxation ratio is 15% or less, the occurrence of slack in the film between the third pinch roll 11 and the take-up roll 13 tends to further suppress the occurrence of wrinkles. Further, when the relaxation ratio is 7% or more, the wrap film can be sufficiently relaxed, and the tearing trouble tends to be reduced. Here, the "relaxation ratio" refers to the ratio of the double ply film 12 contracted between the third pinch roll 11 and the take-up roll 13. For example, in the case of FIG. 1, the winding with respect to the rotation speed of the third pinch roll 11 It can be calculated using the ratio of the take roll 13.

The atmospheric temperature in the relaxation step using the third pinch roll 11 and the take-up roll 13 is preferably 25 to 32 ° C. When the atmospheric temperature is within the above range, the formation and growth of microcrystals tend to be suppressed.

(Slit process)
The wrap film wound as described above is slit and wound while being peeled off to form a single wrap film, and is temporarily stored in the original state for 1 to 3 days. Finally, the raw fabric is rewound from the original fabric to a core such as a paper tube and packed in a cosmetic box to obtain a wrap film wound body stored in the cosmetic box.

(Storage process)
In the method for producing a wrap film of the present embodiment, a storage step may be performed in which the wrap film is slit and then stored in the original state. The storage temperature is preferably 19 ° C. or lower, more preferably 5 to 19 ° C., and even more preferably 5 to 15 ° C. The storage time is preferably 20 to 50 hours, more preferably 24 to 40 hours.

The atmospheric temperature during storage tends to suppress the formation and growth of microcrystals that induce an increase in film tearing troubles. In general, the storage place of the raw fabric is often at a relatively high temperature because it is not adjacent to the manufacturing process of the wrap film or is not controlled by temperature control.

On the other hand, in the method for producing a wrap film of the present embodiment, the physical deterioration of the film due to the rearrangement of the molecular chains tends to be suppressed by setting the atmospheric temperature at the time of storing the slit raw fabric to 19 ° C. or lower. .. This makes it easier for the wrap film to tear from the end cut by the cutting blade attached to the cosmetic box when pulling out the wrap film from the winding body or when picking out the end of the film that has been rewound into the cosmetic box. Tends to be suppressed.

In addition, since the atmospheric temperature during storage of the slit original fabric is 5 ° C or higher, the wrap film is sufficiently relaxed, and when it is exposed to 20 ° C or higher during subsequent distribution and storage, the molecular chain rearrangement is unlikely to occur. It tends to be.

Therefore, it is preferable to store the original slit fabric under the above-mentioned storage conditions, whereby a film in which the molecular chain of the amorphous portion is relaxed while suppressing the formation and growth of microcrystals can be obtained. In this way, by relaxing the orientation of the molecular chains during storage of the raw fabric, it becomes difficult for microcrystals to form and grow even when the film is exposed to high temperatures during distribution and storage, and tearing trouble can be suppressed.

After storage, the slit original fabric is not particularly limited, but is rewound to, for example, a winding core such as a paper tube, and is stored as a winding body 16 in a cosmetic box 1 provided with a film cutting blade 15 as shown in FIG. As illustrated in FIG. 2, the wrap film 17 is pulled out and used at the time of use.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. The evaluation methods used in the examples and comparative examples are as follows.

[Contents of constituent units derived from vinylidene chloride and vinyl chloride]
The contents of the constituent units derived from vinylidene chloride and the constituent units derived from vinyl chloride were measured using a highly decomposed proton nuclear magnetic resonance measuring device. The reprecipitated filtrate of the wrap film was vacuum dried, and a solution prepared by dissolving 5% by mass in deuterated tetrahydrofuran was measured by 1 H-NMR in a measurement atmosphere of 23 ± 2 ° C. and 50 ± 10% RH.
For example, the structural unit derived from vinylidene chloride (-CH ₂ -CCl _{2-) is expressed as A, and the structural unit derived from vinyl chloride (-CH 2 -} CHCl-) is expressed as B, and signals 1, 2, and appearing on the spectrum are expressed as B. And 3 were attributed as follows.
Signal 1 (about 5.2-4.5 ppm) was assigned to the CH signal of B (the methine (CH) group of the building blocks derived from vinyl chloride).
-Signal 2 (about 4.2-3.8 ppm) was assigned to the CH ₂ signal (methylene (CH ₂ ) group of the building block derived from vinylidene chloride) of A on one side of AA.
Signal 3 (approximately 3.5-2.8 ppm) was assigned to the CH ₂ signal (methylene (CH ₂ ) group of the building block derived from vinylidene chloride) of A in both AB and BA.

The mole fraction of the constituent units was determined from the spectral area values of these signals (the area of the signals in the NMR spectrum). In addition, each mole fraction is expressed as follows.
-Mole fraction of A (mol%): P (A)
-Mole fraction of B (mol%): P (B)

From the area values of signals 1, 2, and 3 (the area of the peak in the NMR spectrum) assigned as described above, the integrated value of the signal on the spectrum was assigned as follows.
-Integral value of signal 1 (about 5.2 to 4.5 ppm) for 1H of B-Integral value of signal 2 (about 4.2 to 3.8 ppm) for 1H2 of A-Signal 3 (about 3) Integral value of .5 to 2.8 ppm) for 1H4 of A

Each mole fraction was calculated using the following equation.
・ P (A) + P (B) = 100

P (A) and P (B) were calculated by the following equations.
P (B): P (A) = Integral value of signal 1: (Integral value of signal 2 + Integral value of signal 3/2) / 2
・ P (A) = 100-P (B)

The molecular weight of A, which is a structural unit derived from vinylidene chloride (-CH ₂ -CCl _{2-), is 97.0, and the molecular weight of B, which is a structural unit derived from vinyl chloride (-CH 2 -} CHCl-), is 62.5. , Each mass fraction was calculated using the following equation. In addition, each mass fraction is expressed as follows.
-Mass fraction of A (mass percent): Q (A)
-Mass fraction of B (mass percent): Q (B)
Q (A) = (P (A) x 97.0) / (P (A) x 97.0 + P (B) x 62.5) x 100
・ Q (B) = 100-Q (A)

[Film thickness]
The thickness of the wrap film was measured using a precision dial gauge (TM-1201 manufactured by Teclock Co., Ltd.) in an atmosphere of 23 ± 2 ° C. and 50 ± 10% RH.

[Evaluation of tear resistance when pulled by 10%]
Assuming an operation of wrapping vegetables while pulling the wrap film in the TD direction, the easiness of tearing of the film when the wrap film was pulled 10% in the TD direction was functionally evaluated. The sensory evaluation regarding the easiness of tearing when the wrap film was pulled in the TD direction by 10% was evaluated by the following method.
Ten skilled evaluators (including men and women) pulled out the wrap film by hand from the wrap film winder wrapped in a paper tube, cut it with scissors, and then cut it 5 cm in the direction parallel to the MD direction. , 5 cm was cut in a direction parallel to the TD direction to prepare a 5 cm × 5 cm wrap film. The obtained sample was stretched by 10% in the TD direction with a stretcher. Using this wrap film, the evaluator performs the action of wrapping the plate, and whether the wrap film feels easy to tear is in 1-point increments of 1 to 10 points (10 points are the most difficult to tear, and 1 point is the most. I felt that it was easy to tear.), And each was evaluated. Based on the average score of 10 evaluators, the tear resistance of the wrap film was evaluated according to the following evaluation criteria.
If the evaluation of the tear resistance is "A", it can be said that the wrap film is very difficult to tear and the film strength is very excellent. If the evaluation is "B", it can be said that the wrap film is hard to tear and the film strength is excellent. If the rating is "C", the wrap film is relatively excellent in tear resistance. If the rating is "D", the wrap film has good tear resistance. If the rating is "E", the wrap film has relatively good tear resistance. If the evaluation is "F", there is no particular problem with the wrap film being resistant to tearing. If the rating is "G", the wrap film is slightly inferior in tear resistance. If the evaluation is "x", the wrap film is inferior in tear resistance.
[Evaluation criteria]
A: 8.0 points or more B: 7.0 points exceeded 8.0 points C: 6.0 points exceeded 7.0 points D: 5.0 points exceeded 6.0 points E: 4.0 points exceeded Less than 5.0 points F: Over 3.0 points Less than 4.0 points G: Over 2.0 points Less than 3.0 points ×: 2.0 points or less

[Evaluation of tear resistance when pulled by 1%]
Assuming the operation of stacking the plate on the wrap film after wrapping the plate while pulling the wrap film in the TD direction, sensory evaluation of the ease of tearing of the film when the wrap film is pulled in the TD direction by 1%. did. The sensory evaluation regarding the easiness of tearing when the wrap film was pulled in the TD direction by 1% was evaluated by the following method.
Ten skilled evaluators (including men and women) pulled out the wrap film by hand from the wrap film winder wrapped in a paper tube, cut it with scissors, and then cut it 5 cm in the direction parallel to the MD direction. , 5 cm was cut in a direction parallel to the TD direction to prepare a 5 cm × 5 cm wrap film. The obtained sample was stretched by 1% in the TD direction with a stretcher. Using this wrap film, the evaluator performs the action of wrapping the plate, and whether the wrap film feels easy to tear is in 1-point increments of 1 to 10 points (10 points are the most difficult to tear, and 1 point is the most. I felt that it was easy to tear.), And each was evaluated. Based on the average score of 10 evaluators, the tear resistance of the wrap film was evaluated according to the following evaluation criteria.
If the evaluation of the tear resistance is "A", it can be said that the wrap film is very difficult to tear and the film strength is very excellent. If the evaluation is "B", it can be said that the wrap film is hard to tear and the film strength is excellent. If the rating is "C", the wrap film is relatively resistant to tearing. If the rating is "D", the wrap film has good tear resistance. If the rating is "E", the wrap film has relatively good tear resistance. If the evaluation is "F", there is no particular problem with the wrap film being resistant to tearing. If the rating is "G", the wrap film is slightly inferior in tear resistance. If the evaluation is "x", the wrap film is inferior in tear resistance.
[Evaluation criteria]
A: 8.0 points or more B: 7.0 points exceeded 8.0 points C: 6.0 points exceeded 7.0 points D: 5.0 points exceeded 6.0 points E: 4.0 points exceeded Less than 5.0 points F: Over 3.0 points Less than 4.0 points G: Over 2.0 points Less than 3.0 points ×: 2.0 points or less

[Evaluation of odor barrier property when pulled by 10%]
Assuming an operation of wrapping vegetables while pulling the wrap film in the TD direction, the wrap film was pulled in the TD direction by 10%, and the odor barrier property when wrapping food was sensory evaluated. The sensory evaluation regarding the odor barrier property when the wrap film was pulled in the TD direction by 10% was carried out and evaluated by the following method.
Ten skilled evaluators (including men and women) pulled out the wrap film by hand from the wrap film winder wrapped in a paper tube, cut it with scissors, and then cut it 5 cm in the direction parallel to the MD direction. , 5 cm was cut in a direction parallel to the TD direction to prepare a 5 cm × 5 cm wrap film. The obtained sample was stretched by 10% in the TD direction with a stretcher. Using this wrap film, the evaluator performs the action of wrapping strawberries, and whether the evaluator feels that it has excellent odor barrier properties is in 1-point increments of 1 to 10 points (10 points feel that odor does not leak, 1 point is the most. I felt that the odor leaked.), And each was evaluated. Based on the average score of 10 evaluators, the odor barrier property of the wrap film was evaluated according to the following evaluation criteria.
If the evaluation of the odor barrier property is "A", it can be said that the wrap film is extremely resistant to odor leakage and has a very excellent odor barrier property. If the evaluation is "B", it can be said that the wrap film is less likely to leak odor and has excellent odor barrier property. If the evaluation is "C", the odor resistance of the wrap film is relatively excellent. If the evaluation is "D", the odor resistance of the wrap film is good. If the evaluation is "E", the odor resistance of the wrap film is relatively good. If the evaluation is "F", there is no particular problem in the odor leakage of the wrap film. If the evaluation is "G", the odor leakage resistance of the wrap film is slightly inferior. If the evaluation is "x", the odor barrier property of the wrap film is inferior.
[Evaluation criteria]
A: 8.0 points or more B: 7.0 points exceeded 8.0 points C: 6.0 points exceeded 7.0 points D: 5.0 points exceeded 6.0 points E: 4.0 points exceeded Less than 5.0 points F: Over 3.0 points Less than 4.0 points G: Over 2.0 points Less than 3.0 points ×: 2.0 points or less

[Evaluation of odor barrier property when pulled by 1%]
Assuming the operation of stacking the plate on the wrap film after wrapping the plate while pulling the wrap film in the TD direction, pull the wrap film 1% in the TD direction to improve the odor barrier property when wrapping food. Sensory evaluation was performed. The sensory evaluation regarding the odor barrier property when the wrap film was pulled in the TD direction by 1% was carried out and evaluated by the following method.
Ten skilled evaluators (including men and women) pulled out the wrap film by hand from the wrap film winder wrapped in a paper tube, cut it with scissors, and then cut it 5 cm in the direction parallel to the MD direction. , 5 cm was cut in a direction parallel to the TD direction to prepare a 5 cm × 5 cm wrap film. The obtained sample was stretched by 1% in the TD direction with a stretcher. Using this wrap film, the evaluator performs the action of wrapping strawberries, and whether the evaluator feels that it has excellent odor barrier properties is in 1-point increments of 1 to 10 points (10 points feel that odor does not leak, 1 point is the most. I felt that the odor leaked.), And each was evaluated. Based on the average score of 10 evaluators, the odor barrier property of the wrap film was evaluated according to the following evaluation criteria.
If the evaluation of the odor barrier property is "A", it can be said that the wrap film is extremely resistant to odor leakage and has a very excellent odor barrier property. If the evaluation is "B", it can be said that the wrap film is less likely to leak odor and has excellent odor barrier property. If the evaluation is "C", the odor resistance of the wrap film is relatively excellent. If the evaluation is "D", the odor resistance of the wrap film is good. If the evaluation is "E", the odor resistance of the wrap film is relatively good. If the evaluation is "F", there is no particular problem in the odor leakage of the wrap film. If the evaluation is "G", the odor leakage resistance of the wrap film is slightly inferior. If the evaluation is "x", the odor barrier property of the wrap film is inferior.
[Evaluation criteria]
A: 8.0 points or more B: 7.0 points exceeded 8.0 points C: 6.0 points exceeded 7.0 points D: 5.0 points exceeded 6.0 points E: 4.0 points exceeded Less than 5.0 points F: Over 3.0 points Less than 4.0 points G: Over 2.0 points Less than 3.0 points ×: 2.0 points or less

Ａ，ｃ：定数
ｗ_peak：ピーク幅
フィッティング範囲は０．３０ｎｍ^-1＜ｑ＜１．０ｎｍ^-1とした。フィッティングはＷａｖｅｍｅｔｒｉｃｓ社製Ｉｇｏｒ Ｐｒｏを用いて行った。得られたｑ_peakより、結晶長周期ｄ＝２π／ｑ_peakを算出した。

ｑ＝４πｓｉｎθ／λ 式（２）
θ：ブラッグ角
ｑ：散乱ベクトルの大きさ
λ：Ｘ線波長

ＴＤ方向に１０％引っ張った際の結晶長周期は、チャック間の長さが、初期長である２ｃｍから１０％伸長した時の結晶長周期を算出した。

また、ＴＤ方向に１％引っ張った際の結晶長周期は、チャック間の長さが、初期長である２ｃｍから１％伸長した時の結晶長周期を算出した。

また、照射ダメージを軽減するためにサンプルの中心からずれた位置にビームを当て、
引張測定中にビームの相対位置が動いていくようにした。
[Crystal length period during stretching]
The crystal length period during TD stretching was determined by performing in-situ small-angle X-ray scattering (SAXS) measurement at the same time as stretching under the following equipment and conditions.
The measurement was performed in an atmosphere of 26 ± 2 ° C. and 50 ± 10% RH.

Equipment: High Brightness Photon Science Research Center SPring-8 Hyogo Prefecture Beamline BL03XU
X-ray wavelength: 0.100 nm
Camera length: 8m
Attenuation plate: Mo 20 μm
Detector: PLATIUS 1M
Exposure time: 0.2s Exposure + 0.4s Rest section: Length 4cm Width 0.5cm Set on the stretching machine chuck so that the initial length is 2cm Pull speed: 1mm / s

Empty cell scattering correction was performed on the obtained X-ray scattering pattern. Then, fan-shaped averaging was performed in the range of azimuth angle ± 20 deg from the stretching direction to obtain SAXS profile I (q) (the definition of the scattering vector q is equation (2)). Further, the SAXS profile I (q) was subjected to Lorentz correction by multiplying it by q ² . The peak position q _peak derived from the crystal long period appearing in the Lorentz-corrected SAXS profile q ² I (q) was obtained by fitting by the equation (1).

A, c: Constant w _peak : Peak width The fitting range was 0.30 nm ^-1 <q <1.0 nm ^-1 . The fitting was performed using Igor Pro manufactured by Wavemetrics. From the obtained q _peak , the crystal length period d = 2π / q _peak was calculated.

q = 4πsin θ / λ equation (2)
θ: Bragg angle q: Scattering vector magnitude λ: X-ray wavelength

For the crystal length period when pulled in the TD direction by 10%, the crystal length period when the length between the chucks was extended by 10% from the initial length of 2 cm was calculated.

Further, for the crystal length period when pulled by 1% in the TD direction, the crystal length period when the length between the chucks was extended by 1% from the initial length of 2 cm was calculated.

Also, in order to reduce irradiation damage, a beam is applied to a position deviated from the center of the sample.
The relative position of the beam was made to move during the tensile measurement.

[Example 1]
Vinylidene chloride resin with a weight average molecular weight of 120,000 (constituent unit derived from vinylidene chloride is 85% by mass, constituent unit derived from vinyl chloride is 15% by mass), ATBC (tributyl acetylcitrate, Taoka Chemical Industry Co., Ltd.), ESO (Newsizer 510R, Nippon Oil & Fats Co., Ltd.) mixed at a ratio of 93.4% by mass, 5.5% by mass, and 1.1% by mass, respectively, a total of 10 kg was mixed with a Henshell mixer for 5 minutes, and 24 After aging for more than an hour, a vinyl chloride resin composition was obtained.
The above vinylidene chloride resin composition is supplied to a melt extruder to be melted, and the heating conditions of the extruder are set so that the molten resin temperature at the slit outlet of the annular die attached to the tip of the extruder becomes 170 ° C. Was extruded in an annular shape at an extrusion rate of 14 kg / hr. The hot distance was 80 mm.
After supercooling this, by inflation stretching, the stretching temperature was 25 ° C., the MD direction was stretched 4.7 times, the TD direction was stretched 5.5 times to form a tubular film, and the folding width was 270 mm. The laminated film was wound at a winding speed of 18 m / min. This film was slit to a width of 80 mm and rewound into a paper tube having an outer diameter of 97 mm while being peeled off into one film. Then, it was stored at 15 ° C. for 30 hours, and wound 20 m on a paper tube having an outer diameter of 36 mm and a length of 23 cm to obtain a wound body of a wrap film. The evaluation results are shown in Table 1.

[Example 2]
A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except that the hot distance was set to 69 mm. The evaluation results are shown in Table 1.

[Example 3]
A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except that the hot distance was set to 65 mm. The evaluation results are shown in Table 1.

[Example 4]
A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except that the hot distance was 59 mm. The evaluation results are shown in Table 1.

[Example 5]
A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except that the hot distance was set to 52 mm. The evaluation results are shown in Table 1.

[Example 6]
A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except that the hot distance was set to 50 mm. The evaluation results are shown in Table 1.

[Example 7]
A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except that the hot distance was set to 49 mm. The evaluation results are shown in Table 1.

[Example 8]
A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except that the hot distance was 47 mm. The evaluation results are shown in Table 1.

[Example 9]
A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except that the hot distance was set to 45 mm. The evaluation results are shown in Table 1.

[Example 10]
A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except that the hot distance was set to 43 mm. The evaluation results are shown in Table 1.

[Example 11]
A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except that the hot distance was set to 42 mm. The evaluation results are shown in Table 1.

[Example 12]
A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except that the hot distance was set to 40 mm. The evaluation results are shown in Table 1.

[Example 13]
The weight average molecular weight of the vinylidene chloride resin is 105,000, the structural unit derived from vinylidene chloride is 84% by mass, the structural unit derived from vinyl chloride is 16% by mass, the amount of ATBC added is 2.3% by mass, and ESO. The addition amount of is 2.2% by mass, the addition amount of DALG is 2.8% by mass, the extrusion rate is 8 kg / hr, the stretching ratio in the MD direction is 3.8 times, and the stretching ratio in the TD direction is 4. A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except that the folding width was set to 201 mm, the folding width was set to 40 mm, and the hot distance was set to 40 mm. The evaluation results are shown in Table 1.

[Example 14]
The weight average molecular weight of the vinylidene chloride resin is 130,000, the structural unit derived from vinylidene chloride is 80% by mass, the structural unit derived from vinyl chloride is 20% by mass, the amount of ATBC added is 5.2% by mass, and ESO. The addition amount is 1.8% by mass, the extrusion rate is 9 kg / hr, the stretching ratio in the MD direction is 4.5 times, the stretching ratio in the TD direction is 3.6 times, the folding width is 176 mm, and the hot distance. A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except that the thickness was set to 40 mm. The evaluation results are shown in Table 1.

[Example 15]
The weight average molecular weight of the vinylidene chloride resin is 130,000, the structural unit derived from vinylidene chloride is 80 mol%, the structural unit derived from vinyl chloride is 20 mol%, the amount of ATBC added is 5.2% by mass, and ESO is added. The amount is 1.8% by mass, the extrusion rate is 8 kg / hr, the draw ratio in the MD direction is 4.9 times, the draw ratio in the TD direction is 3.1 times, the folding width is 152 mm, and the hot distance is 40 mm. A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except for the above. The evaluation results are shown in Table 1.

[Comparative Example 1]
A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except that the hot distance was set to 35 mm. The evaluation results are shown in Table 2.

[Comparative Example 2]
A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except that the hot distance was set to 85 mm. The evaluation results are shown in Table 2.

[Comparative Example 3]
The weight average molecular weight of the vinylidene chloride resin is 105,000, the structural unit derived from vinylidene chloride is 84 mol%, the structural unit derived from vinyl chloride is 16 mol%, the amount of ATBC added is 2.3% by mass, and ESO is added. The amount is 2.2% by mass, the amount of DALG added is 2.8% by mass, the extrusion rate is 8 kg / hr, the stretching ratio in the MD direction is 3.8 times, and the stretching ratio in the TD direction is 4.1 times. A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except that the folding width was set to 201 mm and the hot distance was set to 35 mm. The evaluation results are shown in Table 2.

[Comparative Example 4]
The weight average molecular weight of the vinylidene chloride resin is 105,000, the structural unit derived from vinylidene chloride is 84 mol%, the structural unit derived from vinyl chloride is 16 mol%, the amount of ATBC added is 2.3% by mass, and ESO is added. The amount is 2.2% by mass, the amount of DALG added is 2.8% by mass, the extrusion rate is 8 kg / hr, the stretching ratio in the MD direction is 3.8 times, and the stretching ratio in the TD direction is 4.1 times. A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except that the folding width was set to 201 mm and the hot distance was set to 85 mm. The evaluation results are shown in Table 2.

[Comparative Example 5]
The weight average molecular weight of the vinylidene chloride resin is 130,000, the structural unit derived from vinylidene chloride is 80 mol%, the structural unit derived from vinyl chloride is 20 mol%, the amount of ATBC added is 5.2% by mass, and ESO is added. The amount is 1.8% by mass, the extrusion rate is 9 kg / hr, the draw ratio in the MD direction is 4.5 times, the draw ratio in the TD direction is 3.6 times, the folding width is 176 mm, and the hot distance is 35 mm. A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except for the above. The evaluation results are shown in Table 2.

[Comparative Example 6]
The weight average molecular weight of the vinylidene chloride resin is 130,000, the structural unit derived from vinylidene chloride is 80 mol%, the structural unit derived from vinyl chloride is 20 mol%, the amount of ATBC added is 5.2% by mass, and ESO is added. The amount is 1.8% by mass, the extrusion rate is 9 kg / hr, the draw ratio in the MD direction is 4.5 times, the draw ratio in the TD direction is 3.6 times, the folding width is 176 mm, and the hot distance is 85 mm. A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except for the above. The evaluation results are shown in Table 2.

[Comparative Example 7]
The weight average molecular weight of the vinylidene chloride resin is 130,000, the structural unit derived from vinylidene chloride is 80 mol%, the structural unit derived from vinyl chloride is 20 mol%, the amount of ATBC added is 5.2% by mass, and ESO is added. The amount is 1.8% by mass, the extrusion rate is 8 kg / hr, the draw ratio in the MD direction is 4.9 times, the draw ratio in the TD direction is 3.1 times, the folding width is 152 mm, and the hot distance is 35 mm. A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except for the above. The evaluation results are shown in Table 2.

[Comparative Example 8]
The weight average molecular weight of the vinylidene chloride resin is 130,000, the structural unit derived from vinylidene chloride is 80 mol%, the structural unit derived from vinyl chloride is 20 mol%, the amount of ATBC added is 5.2% by mass, and ESO is added. The amount is 1.8% by mass, the extrusion rate is 8 kg / hr, the draw ratio in the MD direction is 4.9 times, the draw ratio in the TD direction is 3.1 times, the folding width is 152 mm, and the hot distance is 85 mm. A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except for the above. The evaluation results are shown in Table 2.

[Comparative Example 9]
The stretching temperature was 26 ° C., the extrusion speed was 12 kg / hr, the stretching ratio in the MD direction was 3.8 times, the stretching ratio in the TD direction was 5.8 times, the folding width was 284 mm, and the hot distance was 10 mm. A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except for the above. The evaluation results are shown in Table 2.

[Comparative Example 10]
Example 1 except that the extrusion speed was 12 kg / hr, the draw ratio in the MD direction was 3.6 times, the draw ratio in the TD direction was 6.0 times, the folding width was 294 mm, and the hot distance was 10 mm. A wound body of a wrap film was obtained by producing in the same manner as in the above. The evaluation results are shown in Table 2.

[Comparative Example 11]
Example 1 except that the extrusion speed was 11 kg / hr, the draw ratio in the MD direction was 3.5 times, the draw ratio in the TD direction was 6.1 times, the folding width was 299 mm, and the hot distance was 10 mm. A wound body of a wrap film was obtained by producing in the same manner as in the above. The evaluation results are shown in Table 2.

[Comparative Example 12]
The stretching temperature was 28 ° C., the extrusion speed was 12 kg / hr, the stretching ratio in the MD direction was 3.4 times, the stretching ratio in the TD direction was 6.5 times, the folding width was 319 mm, and the hot distance was 10 mm. A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except for the above. The evaluation results are shown in Table 2.

[Comparative Example 13]
The stretching temperature was 32 ° C., the extrusion speed was 13 kg / hr, the stretching ratio in the MD direction was 3.7 times, the stretching ratio in the TD direction was 6.6 times, the folding width was 323 mm, and the hot distance was 10 mm. A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except for the above. The evaluation results are shown in Table 2.

[Comparative Example 14]
The stretching temperature was 26 ° C., the extrusion speed was 12 kg / hr, the stretching ratio in the MD direction was 3.8 times, the stretching ratio in the TD direction was 5.8 times, the folding width was 284 mm, and the hot distance was 10 mm. A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except for the above. The evaluation results are shown in Table 3.

[Comparative Example 15]
Example 1 except that the extrusion speed was 12 kg / hr, the draw ratio in the MD direction was 3.6 times, the draw ratio in the TD direction was 6.0 times, the folding width was 294 mm, and the hot distance was 10 mm. A wound body of a wrap film was obtained by producing in the same manner as in the above. The evaluation results are shown in Table 3.

[Comparative Example 16]
Example 1 except that the extrusion speed was 11 kg / hr, the draw ratio in the MD direction was 3.5 times, the draw ratio in the TD direction was 6.1 times, the folding width was 299 mm, and the hot distance was 10 mm. A wound body of a wrap film was obtained by producing in the same manner as in the above. The evaluation results are shown in Table 3.

[Comparative Example 17]
The stretching temperature was 27 ° C., the extrusion speed was 13 kg / hr, the stretching ratio in the MD direction was 3.8 times, the stretching ratio in the TD direction was 6.4 times, the folding width was 313 mm, and the hot distance was 10 mm. A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except for the above. The evaluation results are shown in Table 3.

[Comparative Example 18]
Except that the stretching temperature was 28 ° C., the stretching ratio in the MD direction was 3.8 times, the stretching ratio in the TD direction was 6.7 times, the folding width was 329 mm, and the hot distance was 10 mm. By producing in the same manner, a wound body of a wrap film was obtained. The evaluation results are shown in Table 3.

[Comparative Example 19]
Except that the stretching temperature was 29 ° C., the stretching ratio in the MD direction was 3.8 times, the stretching ratio in the TD direction was 6.8 times, the folding width was 334 mm, and the hot distance was 10 mm. By producing in the same manner, a wound body of a wrap film was obtained. The evaluation results are shown in Table 3.

[Comparative Example 20]
Example 1 except that the extrusion speed was 12 kg / hr, the draw ratio in the MD direction was 3.7 times, the draw ratio in the TD direction was 5.8 times, the folding width was 284 mm, and the hot distance was 10 mm. A wound body of a wrap film was obtained by producing in the same manner as in the above. The evaluation results are shown in Table 3.

[Comparative Example 21]
Example 1 except that the extrusion speed was 12 kg / hr, the draw ratio in the MD direction was 3.6 times, the draw ratio in the TD direction was 6.1 times, the folding width was 299 mm, and the hot distance was 10 mm. A wound body of a wrap film was obtained by producing in the same manner as in the above. The evaluation results are shown in Table 3.

[Comparative Example 22]
Example 1 except that the extrusion speed was 12 kg / hr, the draw ratio in the MD direction was 3.5 times, the draw ratio in the TD direction was 6.2 times, the folding width was 304 mm, and the hot distance was 10 mm. A wound body of a wrap film was obtained by producing in the same manner as in the above. The evaluation results are shown in Table 3.

[Comparative Example 23]
Example 1 except that the extrusion speed was 11 kg / hr, the draw ratio in the MD direction was 3.4 times, the draw ratio in the TD direction was 5.8 times, the folding width was 284 mm, and the hot distance was 10 mm. A wound body of a wrap film was obtained by producing in the same manner as in the above. The evaluation results are shown in Table 3.

[Comparative Example 24]
Example 1 except that the extrusion speed was 11 kg / hr, the draw ratio in the MD direction was 3.5 times, the draw ratio in the TD direction was 5.8 times, the folding width was 284 mm, and the hot distance was 10 mm. A wound body of a wrap film was obtained by producing in the same manner as in the above. The evaluation results are shown in Table 3.

[Comparative Example 25]
The stretching temperature was 33 ° C., the extrusion speed was 16 kg / hr, the stretching ratio in the MD direction was 3.8 times, the stretching ratio in the TD direction was 7.6 times, the folding width was 372 mm, and the hot distance was 10 mm. A wound body of a wrap film was obtained by producing in the same manner as in Example 1 except for the above. The evaluation results are shown in Table 3.

As shown in Table 1, the wrap films obtained in Examples 1 to 15 did not cause tearing trouble when pulled in the TD direction by about 10%, and the odor of the contents did not leak out.

Claims (5)

A wrap film containing a vinylidene chloride resin, wherein the size of the crystal length cycle when pulled by 10% in the TD direction is 8.2 nm or more and 14.5 nm or less. The vinylidene chloride-based resin wrap film according to claim 1, wherein the size of the crystal length period when pulled by 1% in the TD direction is 7.5 nm or more and 13.5 nm or less. The vinylidene chloride-based resin wrap film according to claim 1 or 2, which has a thickness of 6 to 18 μm. 1 The vinylidene chloride resin wrap film according to the section. The vinylidene chloride-based resin wrap film according to any one of claims 1 to 4 and a winding core are included.
A wound body in which the vinylidene chloride resin wrap film is wound around the core.

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