JP7265447B2 - Vinylidene chloride resin film - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vinylidene chloride resin film, and more particularly to a vinylidene chloride resin film suitable for packaging food products, particularly minced meat products such as sausages and hams.

Conventionally, ground meat products such as sausages and hams have been sold in a form filled and packaged mainly in a cylindrical resin film for the purpose of high-temperature sterilization, long-term storage, and the like. As the resin film, a vinylidene chloride-based resin film, which is excellent in gas barrier properties (oxygen gas barrier properties, water vapor barrier properties), heat resistance, etc., is widely used.

In the vinylidene chloride resin film, a large amount of ground meat product may be left on the surface of the film when the film is peeled off due to chemical bonding between the filled and packaged ground meat product and the film or excessive adhesion between the two. There has been a problem of a decrease in commercial value, such as a decrease in the amount of edible contents and a loss of appearance due to adherence of .

Therefore, as a method for improving the peelability (the film can be easily peeled off from the minced meat product), for example, Patent Document 1 discloses polyglycerol stearic acid as a meat peeling agent with respect to 100% by weight of vinylidene chloride resin. A vinylidene chloride resin film containing 0.1 to 3.0% by weight of ester is described. Further, in Patent Document 2, 0.05 to 1.5 parts by weight of an ester of a fatty acid component having 19 to 25 carbon atoms and a polyglycerin component is contained as a peeling agent with respect to 100 parts by weight of a vinylidene chloride resin. A vinylidene chloride-based resin film is described.
However, the demand for peeling properties of films has been increasing more and more, and conventional peeling agents such as those described in Patent Documents 1 and 2 can sufficiently meet the recent high level of demand even if the amount added is increased. However, there is a problem that the transparency of the film is lowered when the amount of addition is increased.

On the other hand, as the meat peelability is improved, there is a tendency that water syneresis (a phenomenon in which water accumulates) occurs between the minced meat product and the film. This separation of water is thought to occur due to the weak thermal shrinkage stress of the film (the force that tightens the minced meat product when the film thermally shrinks).
As a film in which the heat shrinkage stress is increased and the film and the object to be packaged are fitted, for example, Patent Document 3 discloses a propylene-based polymer having a melt flow rate at 230 ° C. of 0.5 to 8.0 g / 10 minutes , an adhesive layer containing a propylene-based acid-modified product, and a gas barrier layer containing an aromatic polyamide-based copolymer, and have a heat shrinkage stress at 120 ° C. of 1.0 to 3.5 MPa. Multilayer films are described.
However, the coextruded stretched multilayer film of Patent Document 3 has room for improvement in terms of the balance with the peelability.

JP-A-6-316641 JP 2005-48109 A Japanese Patent Application Laid-Open No. 2010-52402

Accordingly, the problem to be solved by the present invention is to provide a vinylidene chloride-based resin film which has an excellent balance between peelability and transparency and which suppresses syneresis.

As a result of intensive studies to solve the above problems, the present inventor added polyglycerol stearic acid ester having a specific molecular weight to vinylidene chloride resin, and measured the heat shrinkage stress at 120 ° C. (according to ASTM D2838). The inventors have found that the above problems can be solved by setting the amount to a specific range, and have completed the present invention.

That is, the present invention is as follows.
[1]
Contains 100 parts by mass of vinylidene chloride resin and 0.1 to 1 part by mass of polyglycerol stearate,
In the molecular weight distribution chart obtained by gel permeation chromatography (GPC) measurement, the polyglycerol stearate ester has a polystyrene-equivalent molecular weight in a region of 200 to 700, a region of 700 to 1400, and a region of 1400 to 4000. Each region of a certain region has a peak top , and the area ratio of the peaks having the peak top in each region is 10 to 40%, 20 to 50%, and 40 to 70%, respectively;
A vinylidene chloride resin film characterized by having a thermal shrinkage stress at 120° C. of 0.8 to 2.0 MPa in both the longitudinal and transverse directions.

ADVANTAGE OF THE INVENTION According to this invention, the vinylidene chloride-type resin film which was excellent in the balance of peelability and transparency, and water syneresis was suppressed can be provided.

FIG. 2 is a diagram showing a molecular weight distribution chart obtained by GPC measurement for polyglycerol stearates A and B used in Examples and Comparative Examples.

[Vinylidene chloride resin film]
The vinylidene chloride resin film of the present embodiment contains 100 parts by mass of vinylidene chloride resin and 0.1 to 1 part by mass of polyglycerol stearate, and the polyglycerol stearate has a molecular weight distribution obtained by GPC measurement. In the chart, the polystyrene-equivalent molecular weight region has at least one peak top in each of the regions of 200 to 700, 700 to 1400, and 1400 to 4000, and the heat shrinkage stress at 120 ° C. It is characterized by being 0.8 to 2.0 MPa in both the vertical and horizontal directions.
By having the above characteristics, the vinylidene chloride resin film of the present embodiment has an excellent balance between peelability and transparency, and water separation is suppressed.

The vinylidene chloride resin film of the present embodiment is not particularly limited, and may be a single layer or multiple layers. A two-layer structure is preferable from the viewpoint of strength and gas barrier properties.
When the vinylidene chloride-based resin film of this embodiment is composed of a plurality of layers, the composition of each layer may be the same or different. In addition, the properties and content of layers other than the layer containing vinylidene chloride resin and polyglycerol stearate are not particularly limited as long as the effects of the present invention are not impaired.

The shape and size of the vinylidene chloride-based resin film of the present embodiment are not particularly limited, and are determined according to the shape, size, etc. of the object to be packaged.
The shape of the vinylidene chloride-based resin film is preferably cylindrical because it facilitates filling of ground meat products such as sausages, hams, etc., in the case that the packaging material is ground meat products.
In addition, when the product to be packaged is a minced meat product such as sausage or ham, the thickness of the vinylidene chloride resin film is preferably 20 to 60 μm as the entire film from the viewpoint of film strength and gas barrier properties. More preferably, it is 30 to 50 μm.

(vinylidene chloride resin)
The vinylidene chloride-based resin contained in the vinylidene chloride-based resin film of the present embodiment is not particularly limited as long as it is a resin containing a vinylidene chloride unit. A copolymer is preferred.
Vinylidene chloride-based resins may be used singly or in combination of two or more.

The monomer copolymerizable with the vinylidene chloride monomer is not particularly limited, but examples include vinyl chloride; vinyl cyanide such as acrylonitrile and methacrylonitrile; aromatic vinyl such as styrene; vinyl esters of aliphatic carboxylic acids of 1 to 18; vinyl polymerizable unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid and itaconic acid, or anhydrides thereof; maleic acid, fumaric acid, itaconic acid and the like Vinyl polymerizable unsaturated carboxylic acid alkyl esters (alkyl group with 1 to 18 carbon atoms); acrylic acid alkyl esters (alkyl group with 1 to 18 carbon atoms) such as methyl acrylate, ethyl acrylate, butyl acrylate and lauryl acrylate 18); Methacrylic acid alkyl esters such as methyl methacrylate, butyl methacrylate and lauryl methacrylate (alkyl group having 1 to 18 carbon atoms); alkyl vinyl ethers having 1 to 18 carbon atoms; olefins such as ethylene, propylene, isobutylene and butadiene etc. Among them, vinyl chloride is preferred.
These monomers may be used individually by 1 type, and may use 2 or more types together.

The vinylidene chloride resin of the present embodiment preferably has a vinylidene chloride unit content of 60 to 99% by mass, more preferably 75 to 96% by mass, from the viewpoint of melting properties during extrusion.
In addition, in this embodiment, the content of vinylidene chloride units can be measured by a nuclear magnetic resonance (NMR) apparatus.

The weight average molecular weight of the vinylidene chloride resin used in this embodiment is preferably 50,000 to 150,000, more preferably 60,000 to 130,000. When the weight-average molecular weight is within the above range, melt extrusion tends to be possible while maintaining melt tension and thermal stability necessary for molding.
In addition, in this embodiment, the weight average molecular weight of the vinylidene chloride resin can be measured by GPC.

The polymerization method of the vinylidene chloride resin is not particularly limited, and the vinylidene chloride resin may be obtained by any of the suspension polymerization method, emulsion polymerization method and solution polymerization method.

The content of the vinylidene chloride resin in the vinylidene chloride resin film of the present embodiment is preferably 80 to 95% by mass, more preferably 85 to 95% by mass. When the content of the vinylidene chloride resin is within the above range, the oxygen impermeability and water vapor impermeability tend to be improved.

(Polyglycerol stearate)
The polyglycerol stearate contained in the vinylidene chloride resin film of the present embodiment has a polystyrene-equivalent molecular weight range of 200 to 700 and a range of 700 to 1400 in the molecular weight distribution chart obtained by GPC measurement. , 1400 to 4000 each have at least one peak top. The molecular weight ranges are preferably 200-650, 700-1300 and 1400-4000.
By using the polyglycerol stearate having the above specific molecular weight, it is possible to obtain a film that exhibits excellent peeling properties and maintains transparency even when the blending amount is small.
In the molecular weight distribution chart obtained by the GPC measurement, the area ratio of peaks having peak tops in each of the regions where the polystyrene equivalent molecular weight is 200 to 700, 700 to 1400, and 1400 to 4000. are not particularly limited, but are preferably 10 to 40%, 20 to 50%, and 40 to 70%, respectively.
FIG. 1 shows a molecular weight distribution chart obtained by GPC measurement of polyglycerol stearates A and B used in Examples and Comparative Examples described later. The polyglycerol stearate A used in the examples has three peaks, and the peak top molecular weights (polystyrene conversion) of each peak are 618, 1270, and 1715, respectively. Moreover, the polyglycerol stearate B used in the comparative example has two peaks, and the molecular weights (in terms of polystyrene) of the peak top of each peak are 1294 and 2015, respectively.

The content of the polyglycerol stearate is 0.1 to 1 part by mass, preferably 0.1 to 0.8 part by mass, more preferably 0.1, based on 100 parts by mass of the vinylidene chloride resin. ~0.7 parts by mass.
When the content of the polyglycerol stearate is within the above range, the skin peeling performance tends to be exhibited while maintaining the transparency.

(Other resins)
The vinylidene chloride-based resin film of the present embodiment may contain other resins than the vinylidene chloride-based resin, if necessary. Other resins include, but are not limited to, ethylene? Vinyl acetate copolymer, (co)polymer of (meth)acrylic acid alkyl ester, methyl methacrylate? butadiene? Styrene copolymers and the like can be mentioned.
Other resins may be used singly or in combination of two or more.
The content of the other resin is preferably 20 parts by mass or less with respect to 100 parts by mass of the vinylidene chloride resin.

(Other additives)
The vinylidene chloride-based resin film of the present embodiment may contain other additives as long as the effects of the present invention are not impaired. Examples of other additives include, but are not particularly limited to, plasticizers, heat stabilizers, lubricants, satin finish agents, colorants, and the like.
Other additives may be used singly or in combination of two or more.
The content of other additives is preferably 20% by mass or less with respect to 100% by mass of the vinylidene chloride resin film.

Examples of plasticizers include, but are not limited to, sebacate esters such as dibutyl sebacate and dioctyl sebacate; citrate esters such as tributyl acetylcitrate; phthalates such as dimethyl phthalate, diethyl phthalate, and dioctyl phthalate. Ester; glycerin, glycerin ester, wax, liquid paraffin, phosphate ester and the like.
A plasticizer may be used individually by 1 type, and may be used in combination of 2 or more types.

Examples of heat stabilizers include, but are not limited to, epoxidized vegetable oils such as epoxidized soybean oil, epoxidized linseed oil, and epoxidized palm oil; epoxidized animal oils; epoxidized fatty acid esters such as epoxidized octyl stearate; Bisphenol A type epoxy resins such as A diglycidyl ether and the like can be mentioned.
A heat stabilizer may be used individually by 1 type, and may be used in combination of 2 or more types.

Examples of lubricants include, but are not particularly limited to, fatty acid amides such as erucamide and stearic acid amide, higher fatty acids, and waxes.
Lubricants may be used singly or in combination of two or more.

Examples of the satin finish agent include, but are not particularly limited to, silicon dioxide and calcium carbonate.
The satin finish agent may be used singly or in combination of two or more.

Examples of the coloring agent include, but are not limited to, organic pigments such as azo-based, phthalocyanine-based, and quinacridone-based pigments; and inorganic pigments such as titanium oxide, carbon black, aluminum, and mica.
The colorants may be used singly or in combination of two or more.

[Method for producing vinylidene chloride resin film]
The method for producing the vinylidene chloride-based resin film of the present embodiment is not particularly limited. The mixture obtained by mixing can be melt-extruded into a sheet-like or tubular shape, etc., and can be produced by stretching as necessary.

The method of mixing the above mixture is not particularly limited, and the mixture can be mixed using a known mixer such as a Henschel mixer or a blender.
The order in which each raw material is added to the kneader is not particularly limited. For example, one type or a plurality of types may be added to the kneader, or all the raw materials may be added at once.

The method of melt extruding and stretching the mixture is not particularly limited, but for example, a method of extruding the mixture into a cylindrical shape using a known melt extruder equipped with an annular die and then stretching using an inflation method. mentioned.

In the inflation method, the film can be stretched in at least one direction, preferably in two directions. A biaxially stretched film has heat shrinkability and is suitably used as a heat-resistant film that can be heat-treated (retort treatment).
When biaxially stretched by the inflation method, the draw ratio in the longitudinal direction is preferably 2.0 to 5.0 times, and the draw ratio in the width direction is preferably 2.0 to 5.0 times. .
The stretching temperature for biaxial stretching by the inflation method is preferably 25 to 34°C, more preferably 25 to 32°C. The lower the stretching temperature, the higher the thermal shrinkage stress of the resulting film tends to be.

The vinylidene chloride-based resin film of the present embodiment is obtained by folding flat a cylindrical film obtained by stretching by an inflation biaxial stretching method with the inner sides overlapping each other and winding it around a core material to form a strip-shaped two-layer film raw material. It is preferable to obtain it as a reverse. At this time, the thickness of the vinylidene chloride-based resin film of the present embodiment is the thickness of two single-layer films (twice the thickness).
Further, after this, the strip-shaped two-layer film raw fabric is unwound as two layers, cut in the longitudinal direction so as to have a desired width, and wound again around the core material to form a package (item to be packaged). A strip-shaped two-layer film stock having a width matching the shape and size may be used.

[Thermal shrinkage stress of vinylidene chloride resin film at 120°C]
The vinylidene chloride resin film of the present embodiment has a heat shrinkage stress at 120 ° C. measured in accordance with ASTM D2838 in the longitudinal direction (longitudinal direction of the original film, that is, the flow direction of the resin) and The opposite width direction, that is, the direction perpendicular to the flow of the resin) is 0.8 to 2.0 MPa. The longitudinal heat shrinkage stress at 120° C. is preferably 0.8-1.8 MPa, more preferably 0.8-1.5 MPa. Also, the lateral heat shrinkage stress at 120° C. is preferably 0.8 to 1.9 MPa, more preferably 0.8 to 1.8 MPa.
When the heat shrinkage stress in both the vertical direction and the horizontal direction at 120 ° C. is 0.8 MPa or more, sufficient stress (tightening force) is applied to the minced meat product during heat treatment (retort treatment), and the minced meat product Since it is possible to prevent air from remaining between the films, separation of water between the film and the ground meat product can be well suppressed, and a good appearance can be maintained. Moreover, when the heat shrinkage stress in both the vertical direction and the horizontal direction at 120° C. is 2.0 MPa or less, it is possible to prevent the film from being broken by the heat treatment.
As a method for controlling the thermal shrinkage stress of the vinylidene chloride resin film at 120° C. in the above ranges in both the longitudinal direction and the transverse direction, for example, a method of adjusting the stretching temperature when stretching the film can be mentioned. The lower it is, the higher the heat shrinkage stress of the resulting film tends to be.
The heat shrinkage stress of the vinylidene chloride resin film at 120° C. is a value measured using a U gauge according to ASTM D2838, and specifically, it is measured by the method described in Examples below. be able to.

[Transparency of vinylidene chloride resin film]
The vinylidene chloride resin film of the present embodiment preferably has a haze of less than 25%, more preferably less than 20%, as measured according to ASTM D1003. When the haze is within the above range, there is a tendency that the appearance of the final product is not impaired.
The haze of the vinylidene chloride resin film is a value measured using a haze meter according to ASTM D1003, and specifically, it can be measured by the method described in Examples below.

[Package]
The package of the present embodiment is obtained by enclosing an object to be packaged with the vinylidene chloride-based resin film of the present embodiment described above.
The shape and size of the package of this embodiment are determined by the shape and size of the object to be packaged, the shape and size of the vinylidene chloride resin film of this embodiment, which is the packaging material, and the like.
In addition, it is preferable that the package of the present embodiment has an outer ear portion extending in the longitudinal direction and having a predetermined width on the outer side of the package, and both ends in the longitudinal direction are converged.

[Method for manufacturing package]
The method for producing the package of the present embodiment is not particularly limited, but for example, the belt-shaped vinylidene chloride resin film of the present embodiment is rolled into a cylindrical shape so that both side edges extending in the longitudinal direction overlap to form a cylindrical film. By continuously sealing the both side edges in the same direction while running the cylindrical film in the longitudinal direction, a cylindrical film having an outer ear portion with a predetermined width extending in the longitudinal direction is formed on the outside. While the cylindrical film is running in the longitudinal direction, the object to be packaged is continuously supplied and filled into the cylindrical film by a nozzle or the like; While the cylindrical film filled with the object to be packaged is running , clipping with a metal wire such as aluminum steel wire or the like at a predetermined longitudinal length, and cutting into individual packages.

As the sealing method, known methods such as welding by high-frequency heating, ultrasonic heating, laser heating, resistance heating, etc., and bonding by adhesive including heat sealing can be used. Among them, high-frequency heating is preferable from the viewpoint of efficiency of sealing and easiness of adjustment of sealing strength because vinylidene chloride-based resin having polarity is included.
In the above-mentioned clipping by wire or the like, the cylindrical film filled with the articles to be packaged is run, and is clipped at two points for each fixed length in the longitudinal direction. As a result, the lower clip of the two clips forms the upper end ligature portion of the previous package, and the upper clip forms the lower end ligature portion of the subsequent package. By cutting between these two clips, the previous and subsequent packages are separated and the individual packages are obtained.

Each of the above manufacturing steps can be performed using an automatic filling and packaging machine, for example, "ADP (registered trademark)" manufactured by Asahi Kasei Corporation.

[Heat treatment of package]
The package of the present embodiment is heat-treated (retorted) by a known method using a known high-temperature and high-pressure cooking and sterilization apparatus. The heat treatment sterilizes the package, and heat shrinkage of the film causes the film to adhere to the object to be packaged, resulting in a package with a good appearance.
The heat treatment conditions can be, for example, a gauge pressure in the heating can of 0.2 MPa and 120° C. for 20 minutes.

Hereinafter, the present embodiment will be described with specific examples and comparative examples, but the present embodiment is not limited to these.

The measurement methods and evaluation methods used in Examples and Comparative Examples are described below.

(1) Thermal shrinkage stress The thermal shrinkage stress at 120°C was measured for the strip-shaped two-layer film raw material for packaging in accordance with ASTM D2838. Specifically, the obtained strip-shaped two-layer film raw material for packaging was cut so that the direction of measurement was the length direction, and a strip test piece having a length of 150 mm, a width of 5 mm, and a thickness of 41 μm was produced. bottom. Five sheets were produced in each of the longitudinal direction (longitudinal direction of the two-layer film material) and the lateral direction (width direction of the two-layer film material). A strip test piece was held between a pair of clips connected to a U gauge and immersed in silicone oil at a bath temperature of 120°C for 5 minutes. The maximum heat shrinkage stress (MPa) after immersion was measured with a U gauge, and the measured values of five sheets were averaged.

(2) Meat Peeling Property Ten heat-treated packages were opened, and the ratio (%) of the area of the portion where the meat was attached to the total area of the film was determined and evaluated according to the following evaluation criteria.
<Evaluation Criteria>
○: The ratio of the area of the portion where the meat is attached is less than 10%.
x: The percentage of the area of the portion where the meat is attached is 10% or more.

(3) Transparency The haze (%) of the film is measured using a haze meter ("NDH5000" manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with ASTM D1003 for the two-layer film raw material for a strip-shaped package, It was evaluated according to the following evaluation criteria.
<Evaluation Criteria>
O: Haze is less than 20%.
Δ: Haze is 20% or more and less than 25%.
x: Haze is 25% or more.

(4) Water Separation State After 10 heat-treated packages were stored at room temperature for 3 weeks, the water separation state between the meat and the film was visually observed and evaluated according to the following evaluation criteria.
<Evaluation Criteria>
◯: Separation of water occurred between the meat and the film.
x: No syneresis occurred between the meat and the film.

Raw materials used in Examples and Comparative Examples are described below.

(1) Vinylidene chloride resin vinylidene chloride-vinyl chloride copolymer (content of vinylidene chloride units/content of vinyl chloride units = 89 mass%/11 mass%, weight average molecular weight 125,000)

(2) Polyglycerol stearate/Polyglycerol stearate A
A polyglycerol stearic acid ester having three peaks in a molecular weight distribution chart obtained by GPC measurement, and having peak top molecular weights (converted to polystyrene) of 618, 1270 and 1715 (see FIG. 1).
・Polyglycerol stearate B
A polyglycerol stearic acid ester having two peaks in a molecular weight distribution chart obtained by GPC measurement and having a peak top molecular weight (converted to polystyrene) of 1294 and 2015 for each peak (see FIG. 1).
The molecular weight of the polyglycerol stearate was measured using a GPC measuring device (“LC-9101” manufactured by Nippon Analytical Industry Co., Ltd.) and converted to polystyrene. A sample solution was prepared by dissolving 100 mg of the sample in chloroform to make 20 mL and filtering through a membrane filter with a pore size of 0.45 μm. The measurement conditions were solvent: chloroform, temperature: 25° C., column: “JAIGEL-2HR” manufactured by Japan Analytical Industry Co., Ltd., flow rate: 9.999 mL/min, detector: RI detector.

(3) Other additives/plasticizer: dibutyl sebacate/heat stabilizer: epoxidized soybean oil/lubricant: erucic acid amide/satin finish agent: silicon dioxide

(4) A kneaded mixture of minced fish and Alaska pollock: 60% by mass, ice water: 20% by mass, egg white: 10% by mass, starch: 7% by mass, and salt: 3% by mass.

[Example 1]
[Production of film]
100 parts by mass of vinylidene chloride-vinyl chloride copolymer, 3 parts by mass of dibutyl sebacate, 2 parts by mass of epoxidized soybean oil, 0.1 parts by mass of erucamide, 0.1 parts by mass of silicon dioxide, poly 0.5 parts by mass of glycerin stearate A was mixed.
After extruding the obtained mixture into a cylindrical shape using a melt extruder equipped with an annular die, the inflation biaxial stretching method is used to stretch the length by 3.0 times and the width direction by 4.0 times. Axial stretching was carried out at a stretching temperature of 30°C. The insides of the obtained cylindrical films were superimposed on each other, folded flat, and wound around a core material to obtain a strip-shaped two-layer film raw fabric (41 μm thick). The obtained strip-shaped two-layer film raw fabric was unwound, cut, and wound again around the core material to produce a strip-shaped two-layer film raw fabric for packaging having a width of 86 mm and a thickness of 41 μm.
[Preparation of package]
Using the strip-shaped two-layer film raw material for a package obtained above, an automatic filling and packaging machine (“ADP (registered trademark)” manufactured by Asahi Kasei Corp.) was used to package minced fish meat to prepare a package. .
Specifically, the belt-shaped two-layer film material for packaging is set in the automatic filling and packaging machine, and the two-layer film material is rolled into a cylindrical shape so that both side edges extending in the longitudinal direction of the two-layer film material overlap. A shaped film was formed. While running the cylindrical film in the longitudinal direction, the both side edges are continuously sealed in the longitudinal direction at a high frequency to form a cylindrical film having an outer ear portion with a width of 7 mm extending in the longitudinal direction on the outside. bottom. While the cylindrical film was running in the longitudinal direction, the minced fish meat was continuously filled into the cylindrical film using a nozzle, and was clipped at two locations with an aluminum steel wire every 200 mm. 200 packages were obtained by cutting between two clips. The production speed was 150/min.
[Heat Treatment of Package]
For 200 packages obtained above, using a high-temperature and high-pressure cooking sterilizer ("RCS-40TGN" manufactured by Hisaka Seisakusho Co., Ltd.), the gauge pressure in the heating can is 0.2 MPa, 120 ° C. for 20 minutes, A heat treatment (retort treatment) was performed.
Table 1 shows the measurement and evaluation results of each physical property.

[Example 2]
The procedure was carried out in the same manner as in Example 1, except that the blending amount of polyglycerol stearate A was changed to 0.7 parts by mass, and the stretching temperature was changed to 28°C.
Table 1 shows the measurement and evaluation results of each physical property.

[Comparative Example 1]
The procedure was carried out in the same manner as in Example 1, except that polyglycerol stearate A was changed to polyglycerol stearate B.
Table 1 shows the measurement and evaluation results of each physical property.

[Comparative Example 2]
The procedure was carried out in the same manner as in Example 2, except that polyglycerol stearate A was changed to polyglycerol stearate B and the stretching temperature was 35°C.
Table 1 shows the measurement and evaluation results of each physical property.

[Comparative Example 3]
The procedure was carried out in the same manner as in Example 1, except that polyglycerol stearate A was changed to polyglycerol stearate B and the amount thereof was changed to 0.7 parts by mass.
Table 1 shows the measurement and evaluation results of each physical property.

In Examples 1 and 2, vinylidene chloride resin films excellent in peelability, transparency, and water separation were obtained.

The vinylidene chloride-based resin film of the present invention has excellent peelability and transparency, and can suppress separation of water from the ground meat product. It can be suitably used as a packaging material for products.

Claims (1)

Contains 100 parts by mass of vinylidene chloride resin and 0.1 to 1 part by mass of polyglycerol stearate,
In the molecular weight distribution chart obtained by gel permeation chromatography (GPC) measurement, the polyglycerol stearate ester has a polystyrene-equivalent molecular weight in a region of 200 to 700, a region of 700 to 1400, and a region of 1400 to 4000. Each region of a certain region has a peak top , and the area ratio of the peaks having the peak top in each region is 10 to 40%, 20 to 50%, and 40 to 70%, respectively;
A vinylidene chloride resin film characterized by having a thermal shrinkage stress at 120° C. of 0.8 to 2.0 MPa in both the longitudinal and transverse directions.

Images