JP2022163706A - wrap film - Google Patents

Abstract

To provide a wrap film which hardly causes a tearing trouble when it is peeled off from food immediately after taken out from a freezer even when it is kept at a low temperature (e.g., -18°C) such as a freezer.SOLUTION: A wrap film contains a vinylidene chloride-based resin, and has a value of 0.8<X/Y<5.0, where X represents a tensile modulus in an MD direction at -18°C and Y represents a tensile modulus in the MD direction at 23°C.SELECTED DRAWING: None

Description

The present invention relates to wrap films.

Vinylidene chloride resins are excellent in properties such as transparency, water resistance and gas barrier properties, and are therefore used as food packaging materials such as wrap films. In recent years, food packaging materials are required to have not only the above properties, but also properties such as molding processability and thermal stability, and to have higher functionality. Examples of methods for making food packaging materials highly functional include a method of blending additives such as plasticizers and heat stabilizers. As such an additive, for example, an epoxidized vegetable oil is used to suppress color tone change of the wrap film.

For example, Patent Document 1 describes a resin composition for a wrap film, which contains a thermoplastic resin and a compound having an ester group and an epoxy group, and the compound has a molecular weight of 300 or more and 1500 or less. is disclosed. Further, for example, Patent Document 2 discloses a vinylidene chloride resin wrap film containing epoxidized vegetable oil and having a coefficient of static friction at 10° C. of 0.3 or more and 0.65 or less.

WO2020/217362 JP 2016-22983 A

By the way, after putting contents such as food into a container made of ceramics, glass, plastic, metal, or wood, the top surface of the container is adhered to the wrap film, the container is sealed, and the contents are stored in a freezer or the like. is widely practiced.

However, conventional wrap films become brittle at low temperatures (usually -18 ° C.) such as in a freezer. However, tear trouble may occur.

The resin composition described in Patent Document 1 can form a wrap film with excellent cold resistance, but only the cold resistance at 0 ° C. is evaluated, and when stored in a freezer (usually -18 ° C.) properties have not been considered.
In addition, the wrap film described in Patent Document 2 also has excellent adhesion at low temperatures, but only the coefficient of static friction at 10 ° C. was evaluated, and the characteristics when stored in a freezer (usually -18 ° C.) were investigated. not.
As described above, both Patent Documents 1 and 2 do not consider use in a freezer, and there is no description of tear trouble.

The present invention has been made in view of the above circumstances, and even if it is stored at a low temperature such as in a freezer (for example, -18 ° C.), it will tear when the wrap film is removed immediately after taking it out of the freezer. To provide a cling film which is less likely to cause cracks.

The present inventors have made intensive studies to solve the above problems. As a result, it was found that the above problems can be solved by controlling the relationship between the tensile modulus in the MD direction at low temperature (−18° C.) and the tensile modulus in the MD direction at room temperature (23° C.). , have completed the present invention.

That is, the present invention is as follows.
[1]
Contains vinylidene chloride resin,
A wrap film in which 0.8<X/Y<5.0, where X is the tensile modulus of elasticity in the MD direction at -18°C and Y is the tensile modulus of elasticity in the MD direction at 23°C.
[2]
The wrap film according to [1], wherein the wrap film contains an epoxidized fatty acid ester compound.
[3]
The wrap film according to [2], wherein the epoxidized fatty acid ester compound is an alicyclic epoxidized fatty acid ester compound.
[4]
The wrap film according to [3], wherein the alicyclic epoxidized fatty acid ester compound is a compound having one epoxidized cyclohexane structure in the molecule.
[5]
The wrap film according to any one of [2] to [4], wherein the content of the epoxidized fatty acid ester compound is 0.1% by mass to 7.0% by mass relative to the total weight of the wrap film.
[6]
The wrap film according to any one of [1] to [5], which has a thickness of 6 μm to 18 μm.

To provide a wrap film which, even when stored at a low temperature (e.g., -18°C) such as in a freezer, does not easily cause tear trouble when the wrap film is peeled off immediately after being taken out of the freezer. becomes possible.

It is a schematic diagram of an example of the manufacturing process of the wrap film of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic of an example of the usage form of the wrap film of this invention.

Hereinafter, an embodiment of the present invention (hereinafter referred to as "this embodiment") will be described in detail, but the present invention is not limited to this, and various modifications are possible without departing from the gist thereof. is.

In this embodiment, the "TD direction" refers to the width direction of the resin in the film production line, and when used as a wrap film, refers to the direction perpendicular to the direction in which the wrap film is pulled out from the roll. The term "MD direction" refers to the direction in which the resin flows in the film production line, and refers to the direction in which the wrap film is pulled out from the roll when the wrap film is formed.

[wrap film]
The wrap film of the present embodiment contains a vinylidene chloride-based resin, and when the tensile modulus of elasticity in the MD direction at −18° C. is X and the tensile modulus of elasticity in the MD direction at 23° C. is Y, 0.8. <X/Y<5.0. The wrap film of the present embodiment has such characteristics, so that even if it is stored at a low temperature such as in a freezer (eg, -18 ° C.), it can be stored at room temperature (eg, 23 ° C.) immediately after being taken out of the freezer. The wrap can be peeled off from a plate or the like without the feeling of use. From the same point of view, 0.8<X/Y<3.0 is preferable, and 0.8<X/Y<1.5 is more preferable. When 0.8<X/Y is satisfied, the wrap can be peeled off from a plate or the like without being stretched more than necessary. When X/Y<5.0, it is possible to reduce the trouble of tearing when the wrap is peeled off.

Although the method for controlling X/Y within the above range is not particularly limited, it can be adjusted, for example, by adjusting the composition of the vinylidene chloride resin, the composition of additives, the draw ratio of the film, the drawing speed, and the like. Specifically, although not particularly limited, for example, when an epoxidized vegetable oil described later is added, the tensile elastic modulus X in the MD direction at −18° C. becomes larger than the tensile elastic modulus Y in the MD direction at 23° C. When the epoxidized fatty acid ester compound described later is added instead of the epoxidized vegetable oil, the tensile elastic modulus X in the MD direction at −18° C. is larger than the tensile elastic modulus Y in the MD direction at 23° C. Instead, it tends to remain the same.

(vinylidene chloride resin)
The vinylidene chloride resin is not particularly limited as long as it contains a vinylidene chloride repeating unit (hereinafter also referred to as "monomer"). Examples include vinylidene copolymers.

The monomer copolymerizable with the vinylidene chloride monomer is not particularly limited, but examples include vinyl chloride; acrylic acid esters such as methyl acrylate and butyl acrylate; methacrylic acid esters such as methyl methacrylate and butyl methacrylate. acrylic acid, methacrylic acid; acrylonitrile; vinyl acetate; These monomers may be used singly or in combination of two or more. Among these, vinyl chloride is more preferable.

The proportion of the vinylidene chloride monomer in the vinylidene chloride copolymer is not particularly limited, but is preferably 72 mol % to 93 mol %, more preferably 81 mol % to 90 mol %. When the proportion of the vinylidene chloride monomer is 72 mol % or more, the glass transition temperature of the vinylidene chloride resin tends to be low and the wrap film tends to be soft. As a result, tearing of the wrap film can be reduced even when used in a low-temperature environment such as in winter. On the other hand, when the proportion of the vinylidene chloride monomer is 93 mol % or less, a significant increase in crystallinity is suppressed, and deterioration of moldability during film stretching tends to be suppressed.
In the vinylidene chloride copolymer, the proportion of the monomer copolymerizable with the vinylidene chloride monomer is not particularly limited. It is more preferable to have

The weight average molecular weight (Mw) of the vinylidene chloride resin is preferably 50,000 to 250,000, more preferably 60,000 to 230,000, still more preferably 80,000 to 200,000. . When the weight average molecular weight (Mw) of the vinylidene chloride resin is within the above range, the mechanical strength of the wrap film tends to be further improved. The vinylidene chloride resin having a weight average molecular weight within the above range is not particularly limited. can be obtained by In the present embodiment, the weight average molecular weight (Mw) can be determined by gel permeation chromatography (GPC method) using a standard polystyrene calibration curve.

In the wrap film of the present embodiment, the content of the vinylidene chloride resin is preferably 81% by mass to 95.5% by mass, more preferably 85% by mass to 94% by mass, and 90% by mass to More preferably, it is 94% by mass. In the wrap film of the present embodiment, when the content of the vinylidene chloride resin is within the above range, the plasticizing effect of the additive or the like reduces the share of melt extrusion, so that the generation of foreign matter tends to be further suppressed. It is in. In addition, when the content of the vinylidene chloride resin is within the above range, it is possible to suppress the film from becoming easily stretched, and the cuttability of the film tends to be further improved.
The method for measuring the content of each component from the wrap film differs depending on the object to be analyzed. For example, the content of the vinylidene chloride resin is obtained by dissolving 0.5 g of a sample in 10 mL of THF (tetrahydrofuran), adding about 30 mL of methanol to precipitate the resin content, and then centrifuging to separate and dry the precipitate. It can be obtained by weight measurement.

(Additive)
The wrap film of the present embodiment may contain additives in addition to the vinylidene chloride resin.
Examples of additives include, but are not limited to, epoxidized fatty acid ester compounds, epoxidized vegetable oils, citric acid esters, dibasic acid esters, and acetylated fatty acid glycerides.

In the wrap film of the present embodiment, the total content of at least one compound selected from the group consisting of epoxidized fatty acid ester compounds, epoxidized vegetable oils, citric acid esters, dibasic acid esters, and acetylated fatty acid glycerides is It is preferably 0% to 10% by mass, more preferably 3% to 7% by mass, and still more preferably 3.5% to 6.5% by mass, relative to the total amount of the film. In the wrap film of the present embodiment, the total content of the above compounds is at least the lower limit, so that the share of melt extrusion can be reduced when the wrap film is produced, and the raw material composition can be extruded smoothly. Thermal decomposition of the vinylidene chloride resin is suppressed by passing through the machine. Therefore, the resulting wrap film has a reduced frequency of occurrence of cuts, and tear troubles are suppressed. Moreover, when the total content of the compounds is equal to or less than the upper limit, the elastic modulus of the wrap film is appropriately increased. Therefore, the cuttability of the wrap film is further improved.

(Epoxidized fatty acid ester compound)
The wrap film of the present embodiment may contain an epoxidized fatty acid ester compound.
Epoxidized vegetable oils have been widely known as stabilizers for extrusion processing of vinylidene chloride resins, and have been added to films using vinylidene chloride resins from the viewpoint of suppressing changes in color tone of films. However, since these epoxidized vegetable oils have large molecular weights, solidification proceeds at low temperatures. Therefore, when epoxidized vegetable oil is added to the wrap film, the modulus of elasticity of the wrap film at low temperatures may be greatly increased depending on the amount added.

The wrap film of the present embodiment contains an epoxidized fatty acid ester-based compound instead of the epoxidized vegetable oil, thereby suppressing color tone change of the film and increasing the elastic modulus of the wrap film at low temperatures. It tends to prevent problems. The reason for this is not clear, but the inventor presumes as follows. That is, since the molecular weight of the epoxidized fatty acid ester-based compound is smaller than that of commonly used epoxidized vegetable oils, it does not solidify even at low temperatures and does not increase the elastic modulus of the wrap film at low temperatures. In particular, alicyclic epoxidized fatty acid ester compounds are considered to have excellent compatibility with vinylidene chloride resins, do not solidify even at low temperatures, and do not increase the elastic modulus of the wrap film at low temperatures.

The epoxidized fatty acid ester compound is not particularly limited, but examples include epoxidized fatty acid 2-ethylhexyl, epoxidized fatty acid isobutyl, 3-(2-xenoxy)-1,2-epoxypropane, and epoxidized tall oil fatty acid. 2-ethylhexyl ester of, epoxidized butadiene-based polymers, and alkyl epoxy stearate.

Among epoxidized fatty acid ester compounds, alicyclic epoxidized fatty acid ester compounds are more preferable for the above reasons. Although the alicyclic epoxidized fatty acid ester compound is not particularly limited, for example, it is preferably a compound having at least one epoxidized cycloalkane structure in the molecule, more specifically, epoxidized cyclohexane in the molecule. A compound having a structure or a compound having an epoxidized cyclopentane structure in the molecule is preferred. Such compounds are not particularly limited. For example, by epoxidizing a compound having at least one cycloalkane ring such as cyclohexane or cyclopentane ring with an appropriate oxidizing agent such as hydrogen peroxide or peracid, can get. Among these, compounds having one epoxidized cycloalkane structure in the molecule are more preferable. A compound having one epoxidized cycloalkane structure in the molecule is preferable because it has a high effect of suppressing an increase in the elastic modulus of the wrap film at low temperatures. From the same point of view, the alicyclic epoxidized fatty acid ester compound is more preferably a compound having one epoxidized cyclohexane structure in the molecule.

The compound having an epoxidized cyclohexane structure in the molecule is not particularly limited, but for example, di-2-ethylhexyl epoxyhexahydrophthalate (4,5-epoxycyclohexane-1,2-dicarboxylate bis(2-ethylhexyl)) , di-n-octyl epoxyhexahydrophthalate, bis(9,10-epoxystearyl) epoxyhexahydrophthalate (4,5-epoxycyclohexane-1,2-dicarboxylate bis(9,10-epoxystearyl)) , di-allyl epoxyhexahydrophthalate, epoxyhexahydrophthalic anhydride, epoxyvinylcyclohexane, 4,5-epoxycyclohexane dioctyl 1,2-dicarboxylate, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane etc.

In the wrap film of the present embodiment, the content of the epoxidized fatty acid ester compound is preferably 0.1% by mass to 7.0% by mass, more preferably 0.1% by mass, based on the total amount of the wrap film. % to 5.0% by mass, more preferably 0.1% to 2.0% by mass. In the wrap film of the present embodiment, when the content of the epoxidized fatty acid ester compound is 0.1% by mass or more, it tends to be possible to suppress color tone change. In addition, in the wrap film of the present embodiment, the content of the epoxidized fatty acid ester compound is 7.0% by mass or less, so that the elastic modulus of the wrap film at low temperatures is not increased, thereby preventing tearing troubles. tend to be suppressed.
In this embodiment, the content of the epoxidized fatty acid ester compound can be measured by, for example, proton NMR.

(epoxidized vegetable oil)
The wrap film of the present embodiment may contain an epoxidized vegetable oil in addition to the epoxidized fatty acid ester compound as long as the effects of the present invention are not impaired. Epoxidized vegetable oils are not particularly limited, but generally include those produced by epoxidizing edible fats and oils. Specifically, the epoxidized vegetable oil is not particularly limited, but examples thereof include epoxidized soybean oil (hereinafter also referred to as "ESO") and epoxidized linseed oil. Among these, epoxidized soybean oil is preferred. The use of such an epoxidized vegetable oil tends to improve the adhesion of the wrap film to wooden containers and plastic containers.

In addition to the epoxidized fatty acid ester compound and epoxidized vegetable oil, the wrap film of the present embodiment may contain at least one compound selected from the group consisting of citric acid esters, dibasic acid esters, and acetylated fatty acid glycerides. . Citric acid esters are preferred from the standpoint of handleability, and acetyl tributyl citrate is particularly preferred.

(Citrate ester)
Examples of citrate esters include, but are not limited to, triethyl citrate, tributyl citrate, acetyl triethyl citrate, acetyl tributyl citrate (hereinafter also referred to as "ATBC"), acetyl citrate tri-n-(2-ethylhexyl ) and the like.

Among these, acetyl tributyl citrate is preferred. By containing acetylated tributyl citrate, the wrap film of the present embodiment tends to plasticize the vinylidene chloride resin, which tends to further improve moldability, and reduces the frequency of cuts. Tear troubles are suppressed, and cuttability tends to be further improved.

In the wrap film of the present embodiment, the content of the citrate ester is preferably 0% by mass to 8% by mass, more preferably 0% by mass to 7% by mass, relative to the total amount of the wrap film. It is preferably 0% by mass to 6.5% by mass. In the wrap film of the present embodiment, when the content of the citric acid ester is within the above range, the moldability tends to be further improved, the frequency of cuts is reduced, and tear troubles are suppressed. , and the cuttability tends to be further improved. The method for measuring the content of each component from the wrap film differs depending on the object to be analyzed. In the present embodiment, the content of the citrate ester is determined by extracting the additive from the wrap film using an organic solvent such as acetone at a temperature 5° C. to 10° C. lower than the boiling point of the extraction solvent, and analyzing the content by gas chromatography. can be obtained.

(dibasic acid ester)
The dibasic acid ester is not particularly limited, but examples thereof include dibutyl adipate, di-n-hexyl adipate, di-2-ethylhexyl adipate, and dioctyl adipate; di-2-ethylhexyl azelate; , Azelate such as octyl azelate; Sebacate such as dibutyl sebacate (hereinafter also referred to as "DBS") and di-2-ethylhexyl sebacate; Phthalic acid such as dimethyl phthalate, diethyl phthalate, and dioctyl phthalate esters.

Among these, aliphatic dibasic acid esters are preferred, and dibutyl sebacate is more preferred. In the wrap film of the present embodiment, the vinylidene chloride resin is plasticized by containing such a dibasic acid ester, and the moldability tends to be further improved, and the frequency of cuts is reduced. Thus, tearing troubles are suppressed, and cuttability tends to be further improved.

In the wrap film of the present embodiment, the content of the dibasic acid ester is preferably 0% to 8% by mass, more preferably 0% to 7% by mass, relative to the total amount of the wrap film, More preferably, it is 0% by mass to 6.5% by mass. The wrap film of the present embodiment has a dibasic acid ester content within the above range, so that the moldability tends to be further improved, the frequency of cuts is reduced, and tear troubles are suppressed. and cuttability tends to be further improved. The method for measuring the content of each component from the wrap film differs depending on the object to be analyzed. In the present embodiment, the content of the dibasic acid ester is determined by extracting the additive from the wrap film using an organic solvent such as acetone at a temperature 5 to 10° C. lower than the boiling point of the extraction solvent, and performing gas chromatography analysis. can be obtained.

(acetylated fatty acid glyceride)
Acetylated fatty acid glycerides include, but are not limited to, acetylated caprylic glyceride, acetylated capric glyceride, acetylated lauric glyceride, acetylated myristate glyceride, acetylated palm kernel oil glyceride, and acetylated coconut oil glyceride. , acetylated castor oil glycerides, and acetylated hydrogenated castor oil glycerides.

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, hereinafter simply referred to as "DALG"), and acetylated triglyceride of lauric acid. . Among these, acetylated lauric acid glyceride is preferable, and acetylated diglyceride of lauric acid is more preferable. In the wrap film of the present embodiment, by using such an acetylated fatty acid glyceride together with an epoxidized fatty acid ester compound, the frequency of occurrence of cuts is reduced, tear troubles are suppressed, and cuttability is further improved. tend to

In the wrap film of the present embodiment, the content of the acetylated fatty acid glyceride is preferably 0% by mass to 8% by mass, more preferably 0% by mass to 7% by mass, relative to the total amount of the wrap film, More preferably, it is 0% by mass to 6.5% by mass. Since the content of the acetylated fatty acid glyceride is within the above range, the wrap film of the present embodiment tends to be more improved in moldability, and the frequency of cuts is reduced to suppress tear troubles. and cuttability tends to be further improved. The method for measuring the content of each component from the wrap film differs depending on the object to be analyzed. In the present embodiment, the content of acetylated fatty acid glycerides is determined by extracting the additive from the wrap film using an organic solvent such as acetone at a temperature 5 to 10° C. lower than the boiling point of the extraction solvent, and performing gas chromatography analysis. can be obtained.

(Other additives)
The wrap film of the present embodiment may contain additives other than those described above. Examples of such additives include, but are not limited to, plasticizers other than the above, stabilizers other than the above, weather resistance improvers, colorants such as dyes or pigments, antifogging agents, antibacterial agents, lubricants, nuclei agents, oligomers such as polyester, and polymers such as MBS (methyl methacrylate-butadiene-styrene copolymer).

Plasticizers other than the above are not particularly limited, but specific examples include glycerin, glycerin esters, waxes, liquid paraffin, and phosphate esters. A plasticizer may be used individually by 1 type, and may be used in combination of 2 or more types.

Stabilizers other than the above are not particularly limited, but specific examples include 2,5-t-butylhydroquinone, 2,6-di-t-butyl-p-cresol, 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 propionate and 4,4′-thiobis-(6-t-butylphenol); laurate, myristate, palmitate, stearate, isostearate, oleate, ricinoleate , 2-ethyl-hexylate, isodecanoate, neodecanoate, and calcium benzoate. A stabilizer may be used individually by 1 type, and may be used in combination of 2 or more types.

The weather resistance improver is not particularly limited, but specific examples include ethylene-2-cyano-3,3'-diphenyl acrylate, 2-(2'-hydroxy-5'-methylphenyl)benzolitriazole, 2 -(2'-Hydroxy-3'-t-butyl-5'-methylphenyl)5-chlorobenzotriazole, 2-hydroxy-4-methoxybenzophenone, and 2,2'-dihydroxy-4-methoxybenzophenone, and the like. be done. The weather resistance improvers may be used singly or in combination of two or more.

Colorants such as dyes or pigments are not particularly limited, but specific examples include carbon black, phthalocyanine, quinacridone, indoline, azo pigments, and red iron oxide. Colorants may be used singly or in combination of two or more.

Antifog agents are not particularly limited, but specific examples include glycerin fatty acid esters, sorbitan fatty acid esters, polyoxyethylene fatty acid alcohol ethers, polyoxyethylene glycerin fatty acid esters, and polyoxyethylene sorbitan fatty acid esters. The antifogging agents may be used singly or in combination of two or more.

The antibacterial agent is not particularly limited, but specific examples thereof include silver-based inorganic antibacterial agents and the like. The antibacterial agents may be used singly or in combination of two or more.

Lubricants are not particularly limited, but specific examples include fatty acid hydrocarbon lubricants such as ethylene bissteramide, butyl stearate, polyethylene wax, paraffin wax, carnauba wax, myristyl myristate and stearyl stearate, and higher fatty acid lubricants. , fatty acid amide lubricants, and fatty acid ester lubricants. Lubricants may be used singly or in combination of two or more.

The nucleating agent is not particularly limited, but specific examples thereof include phosphate ester metal salts and the like. Nucleating agents may be used singly or in combination of two or more.

In the wrap film of the present embodiment, the content of other additives is preferably 5% by mass or less, more preferably 3% by mass or less, and still more preferably 1% by mass or less, relative to the total amount of the wrap film. Particularly preferably, it is 0.1% by mass or less. Also, the lower limit of the content of other additives is not particularly limited, but is 0% by mass or more with respect to the total amount of the wrap film.

(tensile modulus in MD direction at 23°C)
The wrap film of the present embodiment preferably has a tensile modulus in the MD direction at 23° C. of 250 MPa to 600 MPa, more preferably 350 MPa to 500 MPa, still more preferably 350 MPa to 470 MPa. The wrap film of the present embodiment has a tensile modulus of elasticity in the MD direction at 23° C. of 250 MPa or more, so that when force is applied to cut the film with a cutting blade, stretching of the film in the MD direction can be suppressed. , the cutting blade can easily bite into the film, and the cutting property tends to be improved. On the other hand, the wrap film of the present embodiment has a tensile modulus of elasticity in the MD direction at 23 ° C. of 600 MPa or less, so that the film is soft, the film can be cut cleanly along the shape of the cutting blade, and many It tends to prevent cracks from forming. As a result, when pulling out the film from the roll and picking up the end of the film rewound in the cosmetic case, it tends to be possible to prevent the film from tearing from the cut end surface.

The MD tensile modulus of the wrap film at 23° C. is not particularly limited, but can be adjusted by, for example, the composition of the vinylidene chloride resin, the additive composition, the draw ratio of the film, the draw speed, and the like. Specifically, although not particularly limited, for example, the tensile modulus of elasticity in the MD direction of the wrap film at 23° C. tends to be improved by increasing the draw ratio or reducing the amount of additives. It tends to decrease by lowering the magnification or increasing the amount of additive. In addition, in this embodiment, the tensile modulus is measured by the method described in Examples below.

(tensile modulus in MD direction at -18°C)
The wrap film of the present embodiment preferably has a tensile modulus in the MD direction at −18° C. of 200 MPa to 2000 MPa, more preferably 250 MPa to 1000 MPa, still more preferably 350 MPa to 700 MPa. The wrap film of the present embodiment has an MD tensile modulus of 200 MPa or more at −18° C., so that the wrap has appropriate hardness. When peeling from the container, the wrap can be easily peeled off without stretching. On the other hand, the wrap film of the present embodiment has a tensile modulus of elasticity in the MD direction at -18 ° C. of 2000 MPa or less, so that the film is soft and when the wrap is removed from the container immediately after being taken out of the freezer at -18 ° C. , It is possible to reduce the trouble of tearing the wrap. As a result, the wrapping film can be peeled off from the container immediately after taking out from the freezer at −18° C. with no inferiority to the feeling of use at room temperature.

The MD tensile modulus of the wrap film at −18° C. is not particularly limited, but can be adjusted by, for example, the composition of the vinylidene chloride resin, the additive composition, the draw ratio of the film, the draw speed, and the like. Specifically, although not particularly limited, for example, the tensile modulus of elasticity in the MD direction of the wrap film at −18° C. tends to be improved by increasing the draw ratio or decreasing the amount of additives. It tends to decrease by lowering the draw ratio or increasing the amount of additives. In addition, in this embodiment, the tensile modulus is measured by the method described in Examples below.

(thickness of wrap film)
The thickness of the wrap film of this embodiment is preferably 6 μm to 18 μm, more preferably 9 μm to 12 μm. When the thickness of the wrap film is within the above range, the problem of film breakage is suppressed, cuttability is further improved, and adhesion tends to be further improved.

More specifically, when the thickness of the wrap film is 6 μm or more, the tear strength of the wrap film in the TD and MD directions is further improved, and the film tends to be more suppressed during use. Further, when the thickness of the wrap film is 6 μm or more, there is a tendency that the tear strength is less likely to decrease significantly. Therefore, when pulling out the wrap film from the roll and when picking up the end of the film rewound in the cosmetic box, the trouble of tearing the wrap film at the edge cut by the cutting blade attached to the cosmetic box is more likely. Suppressed.

On the other hand, when the thickness of the wrap film is 18 μm or less, the force required to cut the wrap film with a cutting blade attached to the cosmetic box can be reduced, and the cuttability tends to be further improved. Further, when the thickness of the wrap film is 18 μm or less, the wrap film tends to fit the shape of the container easily, and the adhesion to the container tends to be further improved.

[Method for producing wrap film]
The method for producing the wrap film of the present embodiment is not particularly limited, but for example, a step of melt extruding a vinylidene chloride resin to form a film, and a step of stretching the obtained film in the MD and TD directions. and a method having A method for producing a wrap film is exemplified below.

(Mixing process)
FIG. 1 shows a schematic diagram of an example of the manufacturing process of the wrap film. First, a mixer is used to mix a vinylidene chloride resin and various additives to obtain a composition. Although the mixer is not particularly limited, for example, a ribbon blender, a Henschel mixer, or the like can be used. The resulting composition is preferably aged for about 1 to 30 hours before use in the next step.

(Melt extrusion process)
The resulting composition is then melted by extruder 1 and a tubular film is extruded from die mouth 3 of die 2 to form sock 4 (also called pile).

(Cooling process)
A sock liquid 5 is injected into the inside of the sock 4, and the outside of the sock 4 is brought into contact with cold water of a cold water tank 6.例文帳に追加As a result, the sock 4 is cooled from both inside and outside, and the film forming the sock 4 is solidified. The solidified sock 4 is folded by a first pinch roll 7 to form a parison 8 .

(Stretching process)
Subsequently, by injecting air into the inside of the parison 8, the parison 8 is opened and an annular film is formed. At this time, the sock liquid 5 applied to the inner surface of the sock 4 works as an opening agent for the parison 8 . The parison 8 is then reheated with hot water to a temperature suitable for stretching while it is open. Hot water adhering to the outside of the parison 8 is squeezed out by the second pinch rolls 9 .

Air is injected into the inside of the parison 8 heated to the appropriate temperature as described above to form the bubble 10 . The air spreads the parison from the inside, stretching the film and obtaining a stretched film. The stretching of the film in the TD direction is mainly performed by the amount of air, and the stretching of the film in the MD direction is performed by applying tension in the film flow direction using the second pinch roll 9 and the third pinch roll 11, etc. done.

The process from the first pinch roll 7 to the third pinch roll 11 is called a stretching process. The draw ratios in the MD direction and the TD direction in the drawing step of the present embodiment are each independently preferably 4 to 6 times, more preferably 4.5 to 5.5 times. Here, the stretch ratio in the MD direction refers to the stretch ratio in which the parison 8 is stretched in the MD direction. For example, in FIG. can be calculated. The draw ratio in the TD direction refers to the draw ratio of the parison 8 stretched in the TD direction. For example, in FIG. can be done. The draw ratio in the MD direction can be adjusted, for example, by the rotation speed ratio of the first pinch roll 7 and the third pinch roll 11, and the draw ratio in the TD direction can be adjusted, for example, by the drawing temperature of the parison 8 and the size of the bubble 10. can be adjusted by

Further, the stretching speed in the MD direction in the stretching step used in this embodiment is preferably 0.09 times/second to 0.12 times/second. The average stretching speed in the MD direction refers to the stretching ratio in the MD direction with respect to the time the parison passes between the first pinch roll 7 and the third pinch roll 11. For example, in FIG. 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, for example, by 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 .

Furthermore, the stretching speed in the TD direction in the stretching step used in this embodiment is preferably 3.1 times/second to 4.0 times/second. 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. It can be calculated from the time required for stretching in the TD calculated from the stretching length and the rotational speed of the third pinch roll 11 and the stretching ratio in the TD. The stretching speed in the TD direction can be adjusted, for example, by the rotation speed of the third pinch rolls 11 .

The resin temperature during stretching is not particularly limited, but is preferably 30°C to 50°C.

After the stretching process, the stretched film is folded by the third pinch rolls 11 to form a double-ply film 12 . The double-ply film 12 is taken up by the take-up roll 13 .

(relaxation process)
In the method for producing a wrap film of the present embodiment, it is preferable to include a relaxation step of relaxing the wrap film immediately after being stretched. A relatively common relaxation method used in the production of wrap films is to relax the film using heat from an infrared heater or the like after stretching. However, in this embodiment, it is preferable to use a method of relaxing the stretched film by making the rotation speed of the take-up roll 13 slower than that of the third pinch roll 11 instead of the relaxation step. This is because, in the present embodiment, when a conventional relaxation method using heat is used, the heat causes the formation and growth of microcrystals, which causes tearing of the film originating from the microcrystals.

The relaxation ratio in the relaxation step using the third pinch roll 11 and 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 wrinkles due to the slackness of the film between the third pinch roll 11 and the take-up roll 13 tends to be more suppressed. In addition, since the relaxation ratio is 7% or more, the wrap film can be sufficiently relaxed, and even when exposed to high temperatures, rearrangement of molecular chains is suppressed and tearing trouble occurs. can be reduced. Here, the “relaxation ratio” refers to the ratio of shrinkage of the double-ply film 12 between the third pinch roll 11 and the take-up roll 13. For example, in the case of FIG. can be calculated using the ratio of the take-up roll 13 to

Further, the ambient temperature in the relaxation step using the third pinch roll 11 and the take-up roll 13 is preferably 25°C to 35°C. When the ambient temperature is within the above range, the formation and growth of microcrystals are suppressed, and there is a tendency to suppress crack troubles caused by the formation and growth of microcrystals.

(Slit process)
The wrap film wound as described above is slit, rolled up while being peeled off so as to form one wrap film, and temporarily stored in the state of the original film for 1 to 3 days. Finally, the raw film is rewound on a paper tube and packed in a cosmetic box to obtain a wrap film roll housed in the cosmetic box.

(Storage process)
In the method of manufacturing the wrap film of the present embodiment, after slitting the wrap film, a storage step of storing the original sheet may be performed. The storage temperature is preferably 19°C or less, more preferably 5°C to 19°C, still more preferably 5°C to 15°C. The storage time is preferably 20 hours to 50 hours, more preferably 24 hours to 40 hours.

The ambient temperature during storage can suppress the formation and growth of microcrystals that cause an increase in film tear troubles. In general, the storage place of the original film is often under a relatively high temperature because it is adjacent to the manufacturing process of the wrap film or the temperature is not controlled.

On the other hand, by setting the ambient temperature at 19° C. or less during storage of the original slit film, it tends to be possible to suppress the physical deterioration of the film due to the rearrangement of the molecular chains. As a result, when pulling out the wrap film from the roll or picking up the end of the film that has been rewound in the presentation box, the edge of the wrap film cut by the cutting blade attached to the presentation box will become easier to tear. can be suppressed.

In addition, since the ambient temperature during storage of the slit raw fabric is 5 ° C or higher, the wrap film is sufficiently relaxed, and when exposed to 19 ° C or higher during subsequent distribution and storage, rearrangement of the molecular chains is unlikely to occur. tend to become

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

After being stored, the slit material is not particularly limited, but is, for example, rewound on a paper tube or the like, and stored as a wound body 16 in a decorative box 14 having a film cutting blade 15 as shown in FIG. As illustrated in FIG. 2, the wrap film 17 is pulled out for use.

Hereinafter, the present invention will be described more specifically using examples and comparative examples. The present invention is by no means limited by the following examples.

[Thickness of wrap film]
Using a dial gauge (manufactured by Teclock), the thickness of the wrap film was measured in an atmosphere of 23° C. and 50% RH.

[Tensile modulus]
Autograph AG-IS (manufactured by Shimadzu Corporation) was used to measure the tensile elastic modulus of the wrap film at 23°C, and evaluation was performed in an atmosphere of 23°C and 50% RH. In order to reproduce the tensile modulus at room temperature, the wrap film sample was stored at 23° C. and RH 50% for 3 hours before measurement, and then the tensile modulus was measured. The load at 2% elongation was measured under the conditions of a tensile speed of 5 mm/min, a distance between chucks of 100 mm, and a film width of 10 mm.
Autograph AG-IS (manufactured by Shimadzu Corporation) and Thermostatic Chamber TCR1-200SP (manufactured by Shimadzu Corporation) were used to measure the tensile modulus of the wrap film at -18°C. After chucking the wrap film sample in a constant temperature bath, it was stored at −18° C. for 3 hours, and then measured for tensile modulus. The load at 2% elongation was measured under the conditions of a tensile speed of 5 mm/min, a distance between chucks of 100 mm, and a film width of 10 mm.
During the measurement, the wrap film sample (test piece) was attached to the clamp so that the MD direction of the wrap film sample coincided with the shaft of the tester. The wrap film samples (specimens) were evenly tightened with grips to prevent slippage and to keep the grips from shifting during the test. Also, the pressure between the grippers should not cause cracking or rolling of the wrap film sample (specimen). In addition, the measurement results were rounded off to the third digit with two significant digits.

[Evaluation of Adhesion at Low Temperature]
In order to evaluate the adhesion of the wrap film in the freezer, the following evaluation was performed.
Cut the prepared wrap film into 220 mm × 220 mm squares, and wrap the rice oil clay (Kutsuwa, 2.5 × 7.5 × 15 cm) divided into two (2.5 × 7.5 × 7.5 cm). A sample was prepared by placing it in the center of the film, folding it in three, and then folding the upper and lower ends in two, just like folding an overwrap. Fifty samples were prepared and stored in a freezer at -18°C for 24 hours. At that time, it was installed in the chamber so that the folded upper and lower ends were on the top surface and that another sample was not placed on top of the sample or overlapped.
After 24 hours, the sample was taken out, and the vertical distance from the top surface of the clay to the edge of the film that was finally folded back was measured, and the adhesion of the wrap film was evaluated according to the following criteria.
[Evaluation criteria]
◎: 10 or less pieces with a distance of 15 mm or more from the top surface of the clay to the film edge ○: 11 to 20 pieces with a distance of 15 mm or more from the top surface of the clay to the film edge △: From the top surface of the clay to the film 21 or more and 30 or less with a distance of 15 mm or more from the edge ×: 31 or more with a distance of 15 mm or more from the top surface of the clay to the edge of the film

[Tear trouble rate]
In order to evaluate the tear trouble rate of the wrap film at normal temperature and in the freezer, the following evaluation was performed.
The prepared wrap film was cut into a 220 mm x 220 mm square and attached to a round plate (12 cm in diameter). 100 samples were prepared, and 50 of them were allowed to stand at 23° C. and 50% RH for 24 hours. The remaining 50 were stored in a -18°C freezer for 24 hours. It was installed in the chamber with care not to place another plate on top of the plate.
After 24 hours, the pan was taken out, the film was immediately peeled off, and the tear trouble of the wrap film at normal temperature and low temperature was evaluated according to the following criteria.
[Evaluation criteria]
◎: The probability that the wrap film will tear is 10% or less ○: The probability that the wrap film will tear is more than 10% and 20% or less △: The probability that the wrap film will tear is more than 20% and 30% or less ×: More than 30% chance of tearing wrap film

[Example 1]
Vinylidene chloride resin having a weight average molecular weight of 90,000 (content of vinylidene chloride monomer is 88 mol%, content of vinyl chloride monomer is 12 mol%) 93.4 parts by mass, acetyl tributyl citrate (hereinafter "ATBC ”, manufactured by Taoka Chemical Co., Ltd.) 5.3 parts by mass, bis(2-ethylhexyl) 4,5-epoxycyclohexane-1,2 dicarboxylate (hereinafter also referred to as “additive A”, trade name: Sanso 1.3 parts by mass of Sizer E-PS (manufactured by Shin Nippon Rika Co., Ltd.) was mixed with a Henschel mixer for 5 minutes. After mixing, the mixture was aged for 24 hours or more to obtain a composition.

The resulting composition was fed to a melt extruder, melted, and melt extruded through an annular die attached to the tip of the extruder to form a sock. At this time, the heating conditions of the extruder were adjusted so that the temperature of the molten resin at the slit outlet of the annular die was 170° C., and the resin was annularly extruded at an extrusion speed of 10 kg/hour.

After cooling with a sock liquid and a cold water bath, the parison was opened to form bubbles and subjected to inflation stretching. At this time, the MD direction was stretched 4.1 times at an average stretching speed of 0.12 times/second, and the TD direction was stretched 5.8 times at an average stretching speed of 3.5 times/second. bubble) was formed.

After the obtained tubular film was nipped and folded flat, the film was relaxed by 10% in the MD direction by controlling the speed ratio between the pinch roll and the take-up roll, and a two-ply film with a folding width of 280 mm was wound. It was taken up at a take-up speed of 18 m/min. This film was slit to a width of 220 mm, peeled off into one film, and rewound on a paper tube having an outer diameter of 92 mm. After that, after being stored at 17° C. for 24 hours, it was wound around a paper tube having an outer diameter of 36 mm and a length of 230 mm for 20 m to obtain a roll of wrap film. Each evaluation was performed using the wound body of the obtained wrap film. Table 1 shows the evaluation results.

[Example 2]
Vinylidene chloride resin with a weight average molecular weight of 90,000 (content of vinylidene chloride monomer is 88 mol%, content of vinyl chloride monomer is 12 mol%) 92.8 parts by mass, acetyl tributyl citrate (Taoka Chemical Industry Co., Ltd.) 5.3 parts by mass, bis(2-ethylhexyl) 4,5-epoxycyclohexane-1,2 dicarboxylate (trade name: Sanso Cizer E-PS, manufactured by Shin Nippon Rika Co., Ltd.) 1.9 The mass parts were mixed for 5 minutes in a Henschel mixer. After mixing, the mixture was aged for 24 hours or more to obtain a composition.
Subsequent extrusion, film forming, and winding steps were performed in the same manner as in [Example 1] to obtain a roll of cling film. Each evaluation was performed using the wound body of the obtained wrap film. Table 1 shows the evaluation results.

[Example 3]
Vinylidene chloride resin with a weight average molecular weight of 90,000 (content of vinylidene chloride monomer is 88 mol%, content of vinyl chloride monomer is 12 mol%) 93.4 parts by mass, acetyl tributyl citrate (Taoka Chemical Industry Co., Ltd.) 0.7 parts by mass, bis(2-ethylhexyl) 4,5-epoxycyclohexane-1,2 dicarboxylate (trade name: Sanso Cizer E-PS, manufactured by Shin Nippon Rika Co., Ltd.) 5.9 The mass parts were mixed for 5 minutes in a Henschel mixer. After mixing, the mixture was aged for 24 hours or more to obtain a composition.
Subsequent extrusion, film forming, and winding steps were performed in the same manner as in [Example 1] to obtain a roll of cling film. Each evaluation was performed using the wound body of the obtained wrap film. Table 1 shows the evaluation results.

[Example 4]
Vinylidene chloride resin having a weight average molecular weight of 90,000 (content of vinylidene chloride monomer: 88 mol%, vinyl chloride monomer content: 12 mol%) 93.0 parts by mass, 4,5-epoxycyclohexane-1 , 2-dicarboxylate bis(2-ethylhexyl) (trade name: Sanso Cizer E-PS, manufactured by Shin Nippon Rika Co., Ltd.) was mixed for 5 minutes with a Henschel mixer. After mixing, the mixture was aged for 24 hours or more to obtain a composition.
Subsequent extrusion, film forming, and winding steps were performed in the same manner as in [Example 1] to obtain a roll of cling film. Each evaluation was performed using the wound body of the obtained wrap film. Table 1 shows the evaluation results.

[Example 5]
Vinylidene chloride resin with a weight average molecular weight of 90,000 (content of vinylidene chloride monomer is 88 mol%, content of vinyl chloride monomer is 12 mol%) 93.6 parts by mass, acetyl tributyl citrate (Taoka Chemical Industry Co., Ltd.) 2.3 parts by mass, diacetyl lauroyl glycerol (hereinafter also referred to as “DALG”, trade name: PL004, manufactured by Riken Vitamin Co., Ltd.) 2.8 parts by mass, 4,5-epoxycyclohexane-1,2 1.3 parts by mass of bis(2-ethylhexyl) dicarboxylate (trade name: Sanso Cizer E-PS, manufactured by Shin Nippon Rika Co., Ltd.) was mixed for 5 minutes with a Henschel mixer. After mixing, the mixture was aged for 24 hours or more to obtain a composition.
Subsequent extrusion, film forming, and winding steps were performed in the same manner as in [Example 1] to obtain a roll of cling film. Each evaluation was performed using the wound body of the obtained wrap film. Table 1 shows the evaluation results.

[Example 6]
Vinylidene chloride resin with a weight average molecular weight of 90,000 (content of vinylidene chloride monomer is 88 mol%, content of vinyl chloride monomer is 12 mol%) 93.4 parts by mass, acetyl tributyl citrate (Taoka Chemical Industry Co., Ltd.) 1.3 parts by mass, DALG (trade name: PL004, manufactured by Riken Vitamin Co., Ltd.) 4.0 parts by mass, bis(2-ethylhexyl) 4,5-epoxycyclohexane-1,2 dicarboxylate ( Product name: Sanso Cizer E-PS, manufactured by Shin Nippon Rika Co., Ltd.) was mixed for 5 minutes with a Henschel mixer. After mixing, the mixture was aged for 24 hours or more to obtain a composition.
Subsequent extrusion, film forming, and winding steps were performed in the same manner as in [Example 1] to obtain a roll of cling film. Each evaluation was performed using the wound body of the obtained wrap film. Table 1 shows the evaluation results.

[Example 7]
Vinylidene chloride resin with a weight average molecular weight of 90,000 (content of vinylidene chloride monomer is 88 mol%, content of vinyl chloride monomer is 12 mol%) 91.7 parts by mass, DALG (PL004, Riken Vitamin Co., Ltd.) )) 7.0 parts by mass, bis(2-ethylhexyl) 4,5-epoxycyclohexane-1,2 dicarboxylate (trade name: Sanso Cizer E-PS, manufactured by Shin Nippon Rika Co., Ltd.) 1.3 parts by mass were mixed in a Henschel mixer for 5 minutes. After mixing, the mixture was aged for 24 hours or more to obtain a composition.
Subsequent extrusion, film forming, and winding steps were performed in the same manner as in [Example 1] to obtain a roll of cling film. Each evaluation was performed using the wound body of the obtained wrap film. Table 1 shows the evaluation results.

[Example 8]
Vinylidene chloride resin with a weight average molecular weight of 90,000 (content of vinylidene chloride monomer is 88 mol%, content of vinyl chloride monomer is 12 mol%) 90.0 parts by mass, acetyl tributyl citrate (Taoka Chemical Industry Co., Ltd.) 7.0 parts by mass, DALG (PL004, Riken Vitamin Co., Ltd.) 1.5 parts by mass, bis(2-ethylhexyl) 4,5-epoxycyclohexane-1,2 dicarboxylate (trade name: 1.5 parts by mass of Sanso Cizer E-PS (manufactured by Shin Nippon Rika Co., Ltd.) was mixed for 5 minutes with a Henschel mixer. After mixing, the mixture was aged for 24 hours or more to obtain a composition.
Subsequent extrusion, film forming, and winding steps were performed in the same manner as in [Example 1] to obtain a roll of cling film. Each evaluation was performed using the wound body of the obtained wrap film. Table 1 shows the evaluation results.

[Example 9]
Vinylidene chloride resin with a weight average molecular weight of 90,000 (content of vinylidene chloride monomer is 88 mol%, content of vinyl chloride monomer is 12 mol%) 93.4 parts by mass, acetyl tributyl citrate (Taoka Chemical Industry Co., Ltd.) 5.3 parts by mass, bis(9,10-epoxystearyl) 4,5-epoxycyclohexane-1,2 dicarboxylate (hereinafter also referred to as “additive B”, trade name: Sansocizer E-PO) , Shin Nippon Rika Co., Ltd.) were mixed for 5 minutes with a Henschel mixer. After mixing, the mixture was aged for 24 hours or more to obtain a composition.
Subsequent extrusion, film forming, and winding steps were performed in the same manner as in [Example 1] to obtain a roll of cling film. Each evaluation was performed using the wound body of the obtained wrap film. Table 1 shows the evaluation results.

[Example 10]
Vinylidene chloride resin with a weight average molecular weight of 90,000 (content of vinylidene chloride monomer is 88 mol%, content of vinyl chloride monomer is 12 mol%) 92.8 parts by mass, acetyl tributyl citrate (Taoka Chemical Industry Co., Ltd.) 5.3 parts by mass, bis(9,10-epoxystearyl) 4,5-epoxycyclohexane-1,2 dicarboxylate (trade name: Sansocizer E-PO, manufactured by Shin Nippon Rika Co., Ltd.) 1.9 parts by mass were mixed in a Henschel mixer for 5 minutes. After mixing, the mixture was aged for 24 hours or more to obtain a composition.
Subsequent extrusion, film forming, and winding steps were performed in the same manner as in [Example 1] to obtain a roll of cling film. Each evaluation was performed using the wound body of the obtained wrap film. Table 1 shows the evaluation results.

[Example 11]
Vinylidene chloride resin with a weight average molecular weight of 90,000 (content of vinylidene chloride monomer is 88 mol%, content of vinyl chloride monomer is 12 mol%) 93.4 parts by mass, acetyl tributyl citrate (Taoka Chemical Industry Co., Ltd.) 0.7 parts by mass, bis(9,10-epoxystearyl) 4,5-epoxycyclohexane-1,2 dicarboxylate (trade name: Sanso Cizer E-PO, manufactured by Shin Nippon Rika Co., Ltd.) 5.9 parts by mass were mixed in a Henschel mixer for 5 minutes. After mixing, the mixture was aged for 24 hours or more to obtain a composition.
Subsequent extrusion, film forming, and winding steps were performed in the same manner as in [Example 1] to obtain a roll of cling film. Each evaluation was performed using the wound body of the obtained wrap film. Table 2 shows the evaluation results.

[Example 12]
Vinylidene chloride resin having a weight average molecular weight of 90,000 (content of vinylidene chloride monomer: 88 mol%, vinyl chloride monomer content: 12 mol%) 93.0 parts by mass, 4,5-epoxycyclohexane-1 7.0 parts by mass of bis(9,10-epoxystearyl),2-dicarboxylate (trade name: Sanso Cizer E-PO, manufactured by Shin Nippon Rika Co., Ltd.) was mixed for 5 minutes with a Henschel mixer. After mixing, the mixture was aged for 24 hours or more to obtain a composition.
Subsequent extrusion, film forming, and winding steps were performed in the same manner as in [Example 1] to obtain a roll of cling film. Each evaluation was performed using the wound body of the obtained wrap film. Table 2 shows the evaluation results.

[Example 13]
Vinylidene chloride resin with a weight average molecular weight of 90,000 (content of vinylidene chloride monomer is 88 mol%, content of vinyl chloride monomer is 12 mol%) 94.9 parts by mass, acetyl tributyl citrate (Taoka Chemical Industry Co., Ltd.) 2.3 parts by mass, DALG (PL004, manufactured by Riken Vitamin Co., Ltd.) 2.8 parts by mass, bis(9,10-epoxystearyl) 4,5-epoxycyclohexane-1,2 dicarboxylate ( Product name: Sanso Cizer E-PO, manufactured by Shin Nippon Rika Co., Ltd.) was mixed for 5 minutes with a Henschel mixer. After mixing, the mixture was aged for 24 hours or more to obtain a composition.
Subsequent extrusion, film forming, and winding steps were performed in the same manner as in [Example 1] to obtain a roll of cling film. Each evaluation was performed using the wound body of the obtained wrap film. Table 2 shows the evaluation results.

[Example 14]
Vinylidene chloride resin with a weight average molecular weight of 90,000 (content of vinylidene chloride monomer is 88 mol%, content of vinyl chloride monomer is 12 mol%) 94.7 parts by mass, acetyl tributyl citrate (Taoka Chemical Industry Co., Ltd.) 1.3 parts by mass, DALG (PL004, Riken Vitamin Co., Ltd.) 4.0 parts by mass, 4,5-epoxycyclohexane-1,2 dicarboxylate bis(9,10-epoxystearyl) ( Product name: Sanso Cizer E-PO, manufactured by Shin Nippon Rika Co., Ltd.) was mixed for 5 minutes with a Henschel mixer. After mixing, the mixture was aged for 24 hours or more to obtain a composition.
Subsequent extrusion, film forming, and winding steps were performed in the same manner as in [Example 1] to obtain a roll of cling film. Each evaluation was performed using the wound body of the obtained wrap film. Table 2 shows the evaluation results.

[Example 15]
Vinylidene chloride resin with a weight average molecular weight of 90,000 (content of vinylidene chloride monomer is 88 mol%, content of vinyl chloride monomer is 12 mol%) 93.6 parts by mass, acetyl tributyl citrate (Taoka Chemical Industry Co., Ltd.) 2.3 parts by mass, DALG (PL004, Riken Vitamin Co., Ltd.) 2.8 parts by mass, epoxidized fatty acid 2-ethylhexyl (hereinafter also referred to as “additive C”, trade name: Sansocizer E -6000, manufactured by Shin Nippon Rika Co., Ltd.) was mixed for 5 minutes with a Henschel mixer. After mixing, the mixture was aged for 24 hours or more to obtain a composition.
Subsequent extrusion, film forming, and winding steps were performed in the same manner as in [Example 1] to obtain a roll of cling film. Each evaluation was performed using the wound body of the obtained wrap film. Table 2 shows the evaluation results.

[Example 16]
Vinylidene chloride resin with a weight average molecular weight of 90,000 (content of vinylidene chloride monomer is 88 mol%, content of vinyl chloride monomer is 12 mol%) 93.4 parts by mass, acetyl tributyl citrate (Taoka Chemical Industry Co., Ltd.) 1.3 parts by mass, DALG (PL004, Riken Vitamin Co., Ltd.) 4.0 parts by mass, epoxidized fatty acid 2-ethylhexyl (trade name: Sanso Cizer E-6000, Shin Nippon Rika Co., Ltd.) 1.3 parts by mass of the product was mixed with a Henschel mixer for 5 minutes. After mixing, the mixture was aged for 24 hours or more to obtain a composition.
Subsequent extrusion, film forming, and winding steps were performed in the same manner as in [Example 1] to obtain a roll of cling film. Each evaluation was performed using the wound body of the obtained wrap film. Table 2 shows the evaluation results.

[Example 17]
Vinylidene chloride resin with a weight average molecular weight of 90,000 (content of vinylidene chloride monomer is 88 mol%, content of vinyl chloride monomer is 12 mol%) 91.7 parts by mass, DALG (trade name: PL004, Riken Vitamin Co., Ltd.) 7.0 parts by mass and 1.3 parts by mass of epoxidized fatty acid 2-ethylhexyl (product name: Sanso Cizer E-6000, manufactured by Shin Nippon Rika Co., Ltd.) were mixed for 5 minutes in a Henschel mixer. did. After mixing, the mixture was aged for 24 hours or more to obtain a composition.
Subsequent extrusion, film forming, and winding steps were performed in the same manner as in [Example 1] to obtain a roll of cling film. Each evaluation was performed using the wound body of the obtained wrap film. Table 2 shows the evaluation results.

[Example 18]
Vinylidene chloride resin with a weight average molecular weight of 90,000 (content of vinylidene chloride monomer is 88 mol%, content of vinyl chloride monomer is 12 mol%) 90.0 parts by mass, acetyl tributyl citrate (Taoka Chemical Industry Co., Ltd.) 7.0 parts by mass, DALG (trade name: PL004, manufactured by Riken Vitamin Co., Ltd.) 1.5 parts by mass, epoxidized fatty acid 2-ethylhexyl (trade name: Sanso Cizer E-6000, Shin Nippon Rika) (manufactured by Co., Ltd.) was mixed for 5 minutes with a Henschel mixer. After mixing, the mixture was aged for 24 hours or more to obtain a composition.
Subsequent extrusion, film forming, and winding steps were performed in the same manner as in [Example 1] to obtain a roll of cling film. Each evaluation was performed using the wound body of the obtained wrap film. Table 2 shows the evaluation results.

[Example 19]
Vinylidene chloride resin with a weight average molecular weight of 90,000 (content of vinylidene chloride monomer is 88 mol%, content of vinyl chloride monomer is 12 mol%) 93.6 parts by mass, acetyl tributyl citrate (Taoka Chemical Industry Co., Ltd.) 2.3 parts by mass, DALG (PL004, Riken Vitamin Co., Ltd.) 2.8 parts by mass, epoxidized fatty acid isobutyl (hereinafter also referred to as "additive D", trade name: Sanso Cizer E-4030 , Shin Nippon Rika Co., Ltd.) were mixed for 5 minutes with a Henschel mixer. After mixing, the mixture was aged for 24 hours or more to obtain a composition.
Subsequent extrusion, film forming, and winding steps were performed in the same manner as in [Example 1] to obtain a roll of cling film. Each evaluation was performed using the wound body of the obtained wrap film. Table 2 shows the evaluation results.

[Example 20]
Vinylidene chloride resin with a weight average molecular weight of 90,000 (content of vinylidene chloride monomer is 88 mol%, content of vinyl chloride monomer is 12 mol%) 93.4 parts by mass, acetyl tributyl citrate (Taoka Chemical Industry Co., Ltd.) 1.3 parts by mass, DALG (PL004, manufactured by Riken Vitamin Co., Ltd.) 4.0 parts by mass, epoxidized fatty acid isobutyl (trade name: Sanso Cizer E-4030, manufactured by Shin Nippon Rika Co., Ltd.) 1.3 parts by mass were mixed for 5 minutes with a Henschel mixer. After mixing, the mixture was aged for 24 hours or more to obtain a composition.
Subsequent extrusion, film forming, and winding steps were performed in the same manner as in [Example 1] to obtain a roll of cling film. Each evaluation was performed using the wound body of the obtained wrap film. Table 2 shows the evaluation results.

[Example 21]
A roll of wrap film was obtained in the same manner as in [Example 1] except that the thickness of the wrap film was 8 μm. Each evaluation was performed using the wound body of the obtained wrap film. Table 2 shows the evaluation results.

[Example 22]
A roll of wrap film was obtained in the same manner as in [Example 1] except that the thickness of the wrap film was 15 μm. Each evaluation was performed using the wound body of the obtained wrap film. Table 2 shows the evaluation results.

[Comparative Example 1]
Vinylidene chloride resin with a weight average molecular weight of 90,000 (content of vinylidene chloride monomer is 88 mol%, content of vinyl chloride monomer is 12 mol%) 92.4 parts by mass, acetyl tributyl citrate (Taoka Chemical Industry Co., Ltd.) 2.3 parts by mass, DALG (trade name: PL004, Riken Vitamin Co., Ltd.) 2.7 parts by mass, epoxidized soybean oil (hereinafter also referred to as “ESO”, trade name “Newsizer 510R”) , manufactured by NOF Co., Ltd.) were mixed for 5 minutes in a Henschel mixer. After mixing, the mixture was aged for 24 hours or more to obtain a composition.
Subsequent extrusion, film forming, and winding steps were performed in the same manner as in [Example 1] to obtain a roll of cling film. Each evaluation was performed using the wound body of the obtained wrap film. Table 3 shows the evaluation results.

[Comparative Example 2]
Vinylidene chloride resin with a weight average molecular weight of 90,000 (vinylidene chloride monomer content: 88 mol%, vinyl chloride monomer content: 12 mol%) 79.0 parts by mass, acetyl tributyl citrate (Taoka Kagaku Kogyo Co., Ltd.) and 19.5 parts by mass of epoxidized fatty acid 2-ethylhexyl (product name: Sanso Cizer E-6000, manufactured by Shin Nippon Rika Co., Ltd.) were mixed for 5 minutes in a Henschel mixer. .
After mixing, the mixture was aged for 24 hours or more to obtain a composition.
Subsequent extrusion, film forming, and winding steps were performed in the same manner as in [Example 1] to obtain a roll of cling film. Each evaluation was performed using the wound body of the obtained wrap film. Table 3 shows the evaluation results.

添加剤Ａ：４，５－エポキシシクロヘキサン－１，２ジカルボン酸ビス（２－エチルヘキシル）
添加剤Ｂ：４，５－エポキシシクロヘキサン－１，２ジカルボン酸ビス（９，１０－エポキシステアリル）
添加剤Ｃ：エポキシ化脂肪酸２－エチルヘキシル
添加剤Ｄ：エポキシ化脂肪酸イソブチル

Additive A: bis(2-ethylhexyl) 4,5-epoxycyclohexane-1,2 dicarboxylate
Additive B: bis(9,10-epoxystearyl) 4,5-epoxycyclohexane-1,2 dicarboxylate
Additive C: epoxidized fatty acid 2-ethylhexyl Additive D: epoxidized fatty acid isobutyl

Even if the wrap film of the present invention is stored at a low temperature such as in a freezer (for example, -18 ° C.), it is difficult to cause tear trouble when the wrap film is peeled off immediately after being taken out of the freezer. It can be used effectively as a use of.

1 extruder 2 die 3 die mouth 4 sock 5 sock liquid 6 cold water tank 7 first pinch roll 8 parison 9 second pinch roll 10 bubble 11 third pinch roll 12 double ply film 13 take-up roll 14 cosmetic box 15 film cutting blade 16 winding body 17 wrap film

Claims (8)

Contains vinylidene chloride resin,
A wrap film in which 0.8<X/Y<5.0, where X is the tensile modulus of elasticity in the MD direction at -18°C and Y is the tensile modulus of elasticity in the MD direction at 23°C. The wrap film according to claim 1, wherein the wrap film contains an epoxidized fatty acid ester compound. The wrap film according to claim 2, wherein the epoxidized fatty acid ester compound is an alicyclic epoxidized fatty acid ester compound. 4. The wrap film according to claim 3, wherein the alicyclic epoxidized fatty acid ester compound is a compound having one epoxidized cyclohexane structure in the molecule. The wrap film according to claim 2, wherein the content of the epoxidized fatty acid ester compound is 0.1% by mass to 7.0% by mass relative to the total weight of the wrap film. The wrap film according to claim 3, wherein the content of the epoxidized fatty acid ester compound is 0.1% by mass to 7.0% by mass relative to the total weight of the wrap film. The wrap film according to claim 4, wherein the content of the epoxidized fatty acid ester compound is 0.1% by mass to 7.0% by mass relative to the total weight of the wrap film. The wrap film according to any one of claims 1 to 7, having a thickness of 6 µm to 18 µm.

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