JP5646858B2 - Film coating agent, wrap film and method for producing the wrap film - Google Patents

Description

  The present invention relates to a film coating agent, a wrap film, and a method for producing the wrap film.

  In business related to foods such as general households and restaurants, polyvinylidene chloride resin wrap films are widely used for storing, packaging or cooking foods and the like. This wrap film is superior in adhesiveness, cut property and gas barrier property as compared to wrap films made of other materials such as polyolefin resin, and is widely spread in the market. Such a wrap film is usually used in a form of being wound in a paper tube and stored in a cosmetic box.

  Although this polyvinylidene chloride wrap film is a good material, there is room for improvement in the physical properties of the polyvinylidene chloride wrap film. For example, when stored for a long time or under high temperature, blocking between wrap films proceeds, and a large force is required when pulling out a wrap film wound in a paper tube from a cosmetic box. . This is not easy to use and causes problems such as tearing of the wrap film when it is forcibly pulled out and paper tubes popping out together with the wrap film. As a measure for solving this problem, a method of adding a lubricant or the like to the resin, the first surface of the film exhibits adhesiveness, and the second surface has less adhesive force than the first surface, or the adhesiveness is increased. For example, a wound wrap film that is not presented (see Patent Document 1) may be used.

Japanese Patent Laid-Open No. 11-301687

  However, even if additives such as a lubricant can be added to the resin to improve the drawability of the film to some extent, there is a problem that the adhesion of the film is lowered. Moreover, since the method of patent document 1 restrict | limits a usage method from the property that only one side has adhesiveness, it imposes inconvenience on a user. Furthermore, since the contents are required to be visible when food or the like is wrapped, the wrapping film is also required to have high transparency.

  This invention is made | formed in view of the said situation, and it aims at providing the film coating agent which can be set as the wrap film which is excellent in the balance of adhesiveness and drawability, and has high transparency. .

  As a result of intensive studies to solve the above-mentioned problems, the present inventor is a film coating agent for coating the surface of a film containing a polyvinylidene chloride resin composition, which contains alcohol and has a specified contact angle with the film It was found that the above problems could be solved by using a film coating agent having a specific value and a vapor pressure at 20 ° C., and the present invention has been completed.

That is, the present invention is as follows.
[1]
A film coating agent applied to the surface of a film containing a polyvinylidene chloride-based resin composition,
Including alcohol,
The film coating agent whose contact angle with the said film is 10-25 degrees, and whose vapor pressure in 20 degreeC is 5-1000 Pa.
[2]
The film coating agent according to [1], which is a sock solution.
[3]
The film coat according to [1] or [2], wherein the alcohol is at least one selected from the group consisting of propylene glycol, isopropanol, 1-butanol, 1-octanol, dipropylene glycol, and tripropylene glycol. Agent.
[4]
A film containing a polyvinylidene chloride resin composition;
The film coating agent according to any one of [1] to [3] applied to at least one surface of the film;
Including wrap film.
[5]
The wrap film according to [4], wherein the coating amount of the film coating agent with respect to the total amount of the film and the film coating agent is 500 to 5000 ppm.
[6]
Extruding a molten vinylidene chloride resin composition from a die into a tubular shape to obtain a tubular extrudate;
A cooling and solidifying step of storing a liquid containing the film coating agent according to any one of [1] to [3] in a hollow portion of the extrudate, and cooling an outer surface of the extrudate with a refrigerant; ,
Inflating the cooled and solidified extrudate;
A method for producing a wrap film comprising:

  ADVANTAGE OF THE INVENTION According to this invention, the film coating agent which can be set as the wrap film which is excellent in the balance of adhesiveness and drawability and has high transparency can be provided.

It is the schematic of an example of the manufacturing process of the wrap film of this Embodiment.

  Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as “the present embodiment”) will be described in detail. The following embodiments are exemplifications for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be implemented with appropriate modifications within the scope of the gist thereof.

[Film coating agent]
The film coating agent of the present embodiment is a film coating agent that coats the surface of a film containing a polyvinylidene chloride-based resin composition, includes alcohol, and a contact angle with the film is 10 to 25 °, And the vapor pressure in 20 degreeC is 5-1000 Pa.

  A wrap film coated with such a film coating agent has an excellent balance between adhesion and drawability, and has high transparency. Since a wrap film coated with a film coating agent having moderate wettability and volatility with respect to a polyvinyl chloride resin film can form a film coating agent layer between the films, Blocking between films can be suppressed. And, when using the wrap film, if the film surface is exposed to the atmosphere, the film coating agent applied to the film surface volatilizes, so that the adhesion between the films and the wrapping container or the like is inhibited. Nor. As a result, good adhesion and drawability can be imparted to the wrap film, and high transparency can be imparted.

  The polyvinylidene chloride resin composition used as a film material includes a polyvinylidene chloride resin. Here, the polyvinylidene chloride resin may be a homopolymer of a vinylidene chloride monomer, or a copolymer of a vinylidene chloride monomer and a monomer copolymerizable with the vinylidene chloride monomer. It may be a polymer.

  The monomer copolymerizable with the vinylidene chloride monomer is not particularly limited, and examples thereof include acrylic acid esters such as vinyl chloride, methyl acrylate and butyl acrylate, and methacrylic acid esters such as methyl methacrylate and butyl methacrylate. , Acrylonitrile, vinyl acetate and the like. Among these, vinyl chloride is preferable from the viewpoint of easy balance between gas barrier properties and extrusion processability and excellent film adhesion. These may be used alone or in combination of two or more.

  When a copolymer of vinylidene chloride monomer and the above monomer is used, from the viewpoint of processability and film physical properties, the vinylidene chloride monomer is 85 to 97% by mass and can be copolymerized therewith. It is preferable that the monomer is a copolymer comprising 15 to 3% by mass. By setting the vinylidene chloride monomer ratio to 86% by mass or more, gas barrier properties and film cutting properties can be further improved, and by setting it to 97% by mass or less, workability can be further improved. The monomer ratio is a value calculated from the integral ratio of the peaks derived from the respective monomer components in the 1H-NMR spectrum measured with FX-270 (manufactured by JEOL Ltd.) using d-THF as a solvent.

  The weight average molecular weight of the polyvinylidene chloride-based resin composition is not particularly limited, but is preferably 70,000 to 110,000, more preferably 80,000 to 100,000. By setting the weight average molecular weight of the polyvinylidene chloride-based resin composition to be equal to or higher than the above lower limit value, it is possible to obtain further favorable film strength, and by setting the weight average molecular weight to be equal to or lower than the above upper limit value, the workability can be further improved. . Here, the weight average molecular weight is a value measured by gel permeation chromatography (GPC) using tetrahydrofuran as a mobile phase, calibrated with polystyrene having a known molecular weight, and converted.

  As long as the effects of the present embodiment are not impaired, additives such as a plasticizer, a stabilizer, and a surfactant may be added to the polyvinylidene chloride resin composition. As these additives, known additives for food packaging materials can also be used.

  Examples of the plasticizer include tributyl acetyl citrate (ATBC), dibutyl sebacate, diacetylated monoglyceride and the like. Examples of the stabilizer include epoxidized soybean oil (ESO) and epoxidized linseed oil. Examples of the surfactant include sorbitan fatty acid esters such as sorbitan monooleate and polyoxyethylene sorbitan monooleate.

  The film coating agent of this Embodiment contains alcohol. The alcohol is a monohydric or polyhydric alcohol. The alcohol is not particularly limited and may be an aliphatic alcohol or an aromatic alcohol, but an aliphatic alcohol is preferred. By including the aliphatic alcohol, not only is the odor low and the handling property and cost are excellent, but also when the wrap film is produced by the inflation method described later, the opening property of the parison can be improved.

  Examples of the aliphatic alcohol include monohydric alcohols such as ethanol (EtOH), isopropanol (IPA), 1-butanol (BtOH), 1-octanol (OcOH), ethylene glycol (EG), diethylene glycol, triethylene glycol, Examples thereof include polyhydric alcohols such as polyethylene glycol, propylene glycol (PG), dipropylene glycol (DPG), tripropylene glycol (TPG), polypropylene glycol, butylene glycol (BG), and glycerin. Examples of the aromatic alcohol include benzyl alcohol.

  Among these, at least one or more selected from the group consisting of propylene glycol, isopropanol, 1-butanol, 1-octanol, dipropylene glycol, and tripropylene glycol is used from the viewpoint of the balance between the adhesiveness and the drawability of the wrap film. Preferably, it contains propylene glycol, more preferably.

  The contact angle of the film coating agent with respect to the film to be applied is 10 to 25 °, preferably 10 to 22 °, more preferably 10 to 20 °. If the contact angle is less than 10 °, the film will have too much wettability, and the film will be impregnated immediately, or blocking between the films will occur, so the balance between adhesion and drawability will deteriorate. On the other hand, when the contact angle exceeds 25 °, the wettability to the film is poor and the transparency is deteriorated.

  The contact angle to the film is measured in an atmosphere of 23 ° C. and 50% RH. The surface of the film immediately after production stretched on a glass plate is washed with water and air-dried, and then 3 μL of a solution contained in a 22-gauge microsyringe is dropped from 5 mm in height. The contact angle 5 seconds after dropping can be measured with an automatic contact angle meter Easy Drop (manufactured by KRUSS).

  The vapor pressure of the film coating agent is 5 to 1000 Pa at 20 ° C. The lower limit of the vapor pressure is preferably 10 Pa or more, more preferably 60 Pa or more, and further preferably 110 Pa or more. The upper limit value of the vapor pressure is preferably 860 Pa or less, more preferably 500 Pa or less. When the vapor pressure is less than 5 Pa, the volatility is low, and the balance between the adhesion of the wrap film and the drawability is poor. On the other hand, when the vapor pressure of the film coating agent exceeds 1000 Pa, the film coating agent volatilizes before use and the desired effect cannot be exhibited, and the viscosity is extremely reduced, and an appropriate application amount is applied. Difficult to do. As the vapor pressure of a single substance, a value measured by a boiling point method using a Sweetoslawski everimeter is used. As the vapor pressure of the mixture, a value calculated from the vapor pressure and the mole fraction of each component is used.

  The viscosity of the film coating agent at 20 ° C. is not particularly limited, but the lower limit is preferably 5 mPa · s or more, more preferably 10 mPa · s or more, further preferably 20 mPa · s or more, and the upper limit is preferably 300 mPa · s or less, more preferably 200 mPa · s or less, and still more preferably 100 mPa · s or less. If the viscosity is not less than the above lower limit value, it becomes easy to apply an appropriate coating amount to the surface of the film, and if the viscosity of the film coating agent is not more than the above upper limit value, moderate volatility can be obtained. And the balance between the adhesiveness and the drawability of the wrap film is further improved. As the viscosity, a value measured by VISCOMETER TV-22 (manufactured by Toki Sangyo Co., Ltd.) can be used based on JIS K7117-2.

[Wrap film]
The wrap film of the present embodiment includes a film containing a polyvinylidene chloride resin composition and the film coating agent applied to at least one surface of the film. A wrap film can be obtained by applying the film coating agent of the present embodiment to the surface of a film containing a polyvinylidene chloride-based resin composition. Here, “apply” means that at least one surface of the film is applied. And in this embodiment, it is not always necessary to completely cover the film surface, and it is sufficient that it is applied to the film surface to the extent that the effect of the present embodiment can be obtained. From this point of view, it can be determined appropriately.

  When the film coating agent of the present embodiment is applied to the surface of the film, the coating amount of the film coating agent is not particularly limited, but the lower limit is preferably 500 ppm or more, more preferably 700 ppm or more, and still more preferably 1000 ppm. As described above, it is more preferably 1300 ppm or more, and the upper limit is preferably 5000 ppm or less, more preferably 3000 ppm or less, and further preferably 1800 ppm or less. When the coating amount is equal to or more than the above lower limit value, the wrap films are less likely to block each other and the drawability is further improved. Moreover, if the application amount is equal to or less than the above upper limit value, the adhesion and transparency are further improved. Here, the coating amount (ppm) represents the mass of the film coating agent with respect to the total mass of the film and the film coating agent in mass ppm. The coating amount (ppm) when the film coating agent is applied to both sides of the film is the total mass of the film coating agent on both sides with respect to the total mass of the film and the film coating agent.

The coating amount can be calculated by previously weighing a coated film (wrap film), extracting a film coating agent from the wrap film, and weighing the extract. A specific method for measuring the coating amount of the film coating agent is shown below.
A sample (film after application) is collected, cut into small pieces, weighed about 2 g, put into a conical flask with a stopper, added with 20 mL of methanol precisely weighed with a whole pipette, stoppered, and 60 ° C. × 1 with a water bath. Extract heat for hours. The obtained extract is subjected to gas chromatography, and the coating amount of the liquid is calculated in parts per million by mass (ppm) from the sample and the mass value of the extract.

  The film coating agent only needs to have a contact angle of 10 to 25 ° with the film containing the above-described polyvinylidene chloride resin composition and a vapor pressure at 20 ° C. of 5 to 1000 Pa. For example, only alcohols The liquid which consists of may be used, and dilution solvents, such as water, may be used together.

  There is no restriction | limiting in particular in the method of apply | coating the film coating agent of this Embodiment to the surface of a film, You may use a conventionally well-known method. For example, it may be applied by roll coating, or when a wrap film is produced by an inflation film forming method to be described later, a polyvinylidene chloride resin composition is melt-extruded from an annular die attached to the tip of an extruder, such as cold water You may pinch with a pinch roll, quenching and solidifying with a refrigerant | coolant, and you may mix and apply to the internal liquid (sock liquid) of the pinched cylindrical parison. The film coating agent of the present embodiment is preferably used as a sock solution in that it can be formed easily at low cost.

[Method of manufacturing wrap film]
Although various methods can be adopted as a method for producing a wrap film containing a polyvinylidene chloride-based resin composition, an inflation film-forming method is usually adopted. Here, an example of the inflation film forming method will be described below.

  After the polyvinylidene chloride resin composition is melt-extruded from a die into a tubular shape, the outside of the tubular resin is brought into contact with a coolant such as cold water filled in a storage tank called a cold water tank. At that time, in a state where the refrigerant is injected and stored in the tubular (tubular) resin sandwiched between the die opening and the pinch roll, the inside is solidified by contacting with a refrigerant such as mineral oil to form a film. Mold. In the present specification, a cylindrical resin portion (extruded product) sandwiched between the die opening and the pinch roll is referred to as “sock”. The refrigerant (liquid) injected into the sock is called “sock liquid”. The sock is folded with the pinch roll or the like to form a tubular double-ply film. This double-ply film is called “parison”.

The manufacturing method of the wrap film of the present embodiment relates to the above-described inflation film forming method,
Extruding a molten vinylidene chloride resin composition from a die into a tubular shape to obtain a tubular extrudate;
A cooling and solidifying step of storing a liquid containing the film coating agent of the present embodiment in the hollow portion of the extrudate, and cooling the outer surface of the extrudate with a refrigerant;
Inflating the cooled and solidified extrudate;
including.

  In such a production method, since the film coating agent is used as a sock solution, the film can be formed easily at low cost, and an appropriate amount of the film coating agent can be uniformly applied to the film surface. As a result, it is possible to efficiently produce a polyvinylidene chloride resin wrap film having an excellent balance between adhesion and drawability and having high transparency.

  Below, an example of the manufacturing method of the wrap film using the film coating agent of this Embodiment is described more concretely. Drawing 1 is a schematic diagram of an example of a manufacturing method of a wrap film of this embodiment.

  First, in the extrusion step, the melted vinylidene chloride resin composition is extruded into a tubular shape from the die port (3) of the circular die (2) by the extruder (1), and sock (tubular vinylidene chloride resin composition) (4) is formed.

  Next, in the cooling and solidifying step, the outside of the sock (4) is brought into contact with cold water in the cold water tank (6), and the sock liquid (5) is injected and stored in the inside of the sock (4) by a conventional method. Thus, the sock (4) is cooled and solidified from inside and outside. At this time, the sock (4) is in a state where the sock liquid (5) is applied to the inside thereof. The solidified sock (4) is folded by a first pinch roll (7) to form a parison (8) which is a double-ply film. The application amount of the sock liquid (5) can be controlled by the pinch pressure of the first pinch roll (7).

  Subsequently, by injecting air into the inside of the parison (8), the parison (8) is opened again and becomes tubular. At this time, the sock liquid (5) applied to the inner surface (inner side) of the sock (4) exhibits an effect as an opening agent of the parison (8). The parison (8) is reheated to a temperature suitable for stretching by warm water (not shown). The warm water adhering to the outside of the parison (8) is squeezed out by the second pinch roll (9).

  Next, in the inflation step, air is injected into the tubular parison (8) heated to an appropriate temperature, and bubbles (10) are formed by inflation stretching to obtain a stretched film. Thereafter, the stretched film is folded by the third pinch roll (11) to form a double-ply film (12). The double ply film (12) is wound up by a winding roll (13). Further, the double-ply film (12) is slit and peeled to become a single film (single peeling). Finally, the double-ply film (12) is wound around a paper tube to obtain a paper tube-wrapped wrap film.

  The above description is an example of a method for producing a wrap film using the film coating agent of the present embodiment, and may be performed according to various apparatus configurations and conditions other than those described above. May be.

  The wrap film obtained by the present embodiment has not only an excellent balance between adhesion and drawability but also high transparency. Furthermore, good adhesion, drawability and transparency can be maintained over a long period of time. About transparency, Preferably a HAZE value is 0 to 3%, More preferably, it is 0 to 2%, More preferably, it is 0 to 1% or less. The HAZE value is measured in accordance with JIS K7136 after 10 seconds of unwinding the paper tube wrapped wrap film. Since the wrap film of the present embodiment is excellent in adhesion, drawability, and the like, it is suitably used as a wrap film (wrapped wrap film) wound around a core such as a paper tube.

  The present invention will be described more specifically with reference to examples and comparative examples. A wrap film was produced according to the method shown in FIG. 1, and its physical properties and the like were evaluated. Evaluation methods used in Examples and Comparative Examples are as follows.

1. Contact angle The contact angle to the film was measured in an atmosphere of 23 ° C. and 50% RH. The film surface immediately after production stretched on a glass plate was washed with water and naturally dried, and then 3 μL of a solution contained in a microsyringe having a height of 5 mm to 22 gauge was dropped. The contact angle 5 seconds after the dropping was measured with an automatic contact angle meter Easy Drop (manufactured by KRUSS).

2. Vapor pressure As the vapor pressure of a single substance, a value measured by a boiling point method using a Swisslawski evryometer was used. As the vapor pressure of the mixture, a value calculated from the vapor pressure and mole fraction of the constituent components alone was used.

3. Viscosity Viscosity was measured with VISCOMETER TV-22 (manufactured by Toki Sangyo Co., Ltd.) based on JIS K7117-2.

4). Coating amount A sample (in FIG. 1, a stretched film after being wound with a winding roll (13)) was collected, finely cut and weighed about 2 g, put into a conical flask with a stopper, and precisely weighed with a whole pipette. Methanol 20 mL was added and stoppered. And it heat-extracted with 60 degreeC * 1 hour with the water bath. The obtained extract was applied to a gas chromatograph (HP6890, manufactured by Hewlett Packard) using methanol as a solvent and DB-WAX as a column, and the liquid was applied from the sample and the mass value of the liquid in the extract. The amount was calculated in parts per million by mass (ppm).

5. Adhesion Assuming that wrap films are used at home, the adhesion between wrap films was evaluated. The measurement was performed in an atmosphere of 23 ° C. and 50% RH. With respect to the wrap film immediately after production and the wrap film stored for one week in a high-temperature bath at 40 ° C., the adhesion work was measured by the method described below.
First, ^two aluminum jigs having a bottom area of 25 cm ² , a height of 55 mm, and a weight of 400 g were prepared, and filter paper having the same area as the bottom area was attached to the bottom surfaces of both jigs. A wrap film was placed on the bottom surface of the jig to which the filter paper was affixed so that no wrinkles entered, and it was fixed with rubber bands. The two jigs covered with the wrap film were put together so that the bottom surfaces on the side covered with the wrap film overlapped, and pressed with a load of 500 g for 1 minute. Next, the work required to peel both wrap film surfaces perpendicularly to the surface at a speed of 5 mm / min was measured with a tensile / compression tester (unit: mJ / 25 cm ² ).

6). Withdrawal Assuming that the wrap film is used at home, the drawability of the paper tube-wrapped wrap film was evaluated. The measurement was performed in an atmosphere of 23 ° C. and 50% RH. The pulling force was measured by the method described below for the wrap film immediately after production and the wrap film stored in a high-temperature bath at 40 ° C. for one week.
A wrap film slit to a width of 30 cm was wound around a paper tube having an outer diameter of 36.6 mm with a length of 20 m. First, the paper tube-wrapped wrap film was fixed to the lower jig of a tensile / compression tester so that only the force required for unwinding the film could be measured. And the front-end | tip of a wrap film was fixed to the upper jig | tool of the tensile tester, and the force required when unwinding a film at a speed | rate of 1000 mm / min was measured (unit: cN / 30cm width).

7). Transparency The transparency of the wrap film was evaluated assuming that the wrap film was used at home. The measurement was performed in an atmosphere of 23 ° C. and 50% RH. About the wrap film immediately after manufacture and the wrap film stored for one week in a 40 degreeC high temperature tank, HAZE was measured by the method shown below.
According to JIS K7136, the paper tube wound wrap film was unwound and the HAZE value after 10 seconds was measured with a turbidimeter (Nippon Denshoku Industries Co., Ltd.) (unit:%).

[Example 1]
Polyvinylidene chloride resin having a weight average molecular weight of 90,000 (90% by mass of vinylidene chloride component, 10% by mass of vinyl chloride component), tributyl acetyl citrate (ATBC, manufactured by Asahi Kasei Finechem), epoxidized soybean oil (ESO, NOF) (Newsizer 510R) manufactured by the company were mixed at a ratio of 93.4% by mass, 5.3% by mass, and 1.3% by mass, respectively, to obtain a polyvinylidene chloride resin composition. The polyvinylidene chloride resin composition was melt extruded at 10.5 kg / hr with a melt extruder while adjusting the heating conditions of the extruder so that the temperature at the outlet of the circular die was 170 ° C., to obtain a sock. In the obtained sock, a liquid in which propylene glycol (PG, manufactured by Mitsui Takeda Chemical Co., Ltd.) and isopropanol (IPA, manufactured by Kanto Chemical Co., Ltd.) was mixed at a volume ratio of 80% / 20% (contact angle with the film of 10 °, Vapor pressure 860 Pa, viscosity 13 mPa · s; sock solution) was injected. Thus, after the parison was supercooled, it was stretched by inflation to obtain a cylindrical film. At this time, the application amount of the mixed liquid was controlled by the pinch pressure of the first pinch roll. The tubular film was pinched and folded flat, and a two-layer film having a folding width of 280 mm and a thickness of 10 μm was wound at a winding speed of 16 m / min.

  The film was slit to a width of 200 mm and peeled so as to form a single film, while winding 20 m on a paper tube having an outer diameter of 36.6 mm and a length of 305 mm to produce a wound wrap film having a thickness of 10 μm. The evaluation results of the obtained film are shown in Table 1.

[Example 2]
A liquid in which PG and 1-butanol (hereinafter referred to as BtOH; manufactured by Kanto Chemical Co., Ltd.) are mixed at a volume ratio of 90% / 10% in the sock (contact angle with film 22 °, vapor pressure 60 Pa, viscosity 16 mPa · s). A wound wrap film having a thickness of 10 μm was produced in the same manner as in Example 1 except that the sock solution was injected. The evaluation results of the obtained film are shown in Table 1.

[Example 3]
Example 1 except that a liquid in which PG and BtOH were mixed at a volume ratio of 80% / 20% (contact angle with a film 10 °, vapor pressure 110 Pa, viscosity 13 mPa · s; sock liquid) was injected into the sock. In the same manner, a wound wrap film having a thickness of 10 μm was produced. The evaluation results of the obtained film are shown in Table 1.

[Examples 4 and 5]
A liquid in which PG and 1-octanol (hereinafter referred to as OcOH, manufactured by Kanto Chemical Co., Ltd.) are mixed at a volume ratio of 80% / 20% in a sock (contact angle with film is 10 °, vapor pressure is 12 Pa, viscosity is 17 mPa · s). A wound wrap film having a thickness of 10 μm was produced in the same manner as in Example 1 except that the sock solution was injected. The evaluation results of the obtained film are shown in Table 1.

[Examples 6 and 7]
The same as in Example 1 except that a liquid (PG contact angle of 10 °, vapor pressure of 17 Pa, viscosity of 13 mPa · s) mixed with 50% / 50% by volume of PG and OcOH was injected into the sock. Thus, a wound wrap film having a thickness of 10 μm was manufactured. The evaluation results of the obtained film are shown in Table 1.

[Example 8]
A liquid in which PG and dipropylene glycol (hereinafter referred to as DPG, manufactured by Asahi Glass Co., Ltd.) are mixed in a sock at a volume ratio of 50% / 50% (contact angle with film 22 °, vapor pressure 7 Pa, viscosity 37 mPa · s) A wound wrap film having a thickness of 10 μm was produced in the same manner as in Example 1 except for the injection. The evaluation results of the obtained film are shown in Table 1.

[Example 9]
A liquid in which PG and tripropylene glycol (hereinafter referred to as TPG; manufactured by Asahi Glass Co., Ltd.) are mixed in a sock at a volume ratio of 50% / 50% (contact angle with film 21 °, vapor pressure 8 Pa, viscosity 30 mPa · s) A wound wrap film having a thickness of 10 μm was produced in the same manner as in Example 1 except for the injection. The evaluation results of the obtained film are shown in Table 1.

[Comparative Example 1]
A wound wrap film having a thickness of 10 μm was produced in the same manner as in Example 1 except that PG (contact angle with the film 30 °, vapor pressure 11 Pa, viscosity 20 mPa · s) was injected into the sock. The evaluation results of the obtained film are shown in Table 2.

[Comparative Example 2]
A wound wrap film having a thickness of 10 μm was produced in the same manner as in Example 1 except that DPG (contact angle with the film 10 °, vapor pressure 1 Pa, viscosity 78 mPa · s) was injected into the sock. The evaluation results of the obtained film are shown in Table 2.

[Comparative Example 3]
A wound wrap film having a thickness of 10 μm was formed in the same manner as in Example 1 except that BG (manufactured by Kanto Chemical Co., Inc.) (contact angle with the film 40 °, vapor pressure 8 Pa, viscosity 90 mPa · s) was injected into the sock. Manufactured. The evaluation results of the obtained film are shown in Table 2.

[Comparative Example 4]
A wound wrap film having a thickness of 10 μm was prepared in the same manner as in Example 1 except that glycerin (manufactured by Kanto Chemical Co., Inc.) (contact angle with film 72 °, vapor pressure <1 Pa, viscosity 940 mPa · s) was injected into the sock. Manufactured. The evaluation results of the obtained film are shown in Table 2.

[Comparative Example 5]
Except that a liquid (PG contact angle of 10 °, vapor pressure of 1300 Pa, viscosity of 10 mPa · s) mixed with PG and IPA at a volume ratio of 70% / 30% was injected into the sock, in the same manner as in Example 1. A wound wrap film having a thickness of 10 μm was produced. The evaluation results of the obtained film are shown in Table 2.

[Comparative Example 6]
Except for injecting a liquid in which PG and IPA were mixed at a volume ratio of 50% / 50% into the sock (contact angle with film: 10 °, vapor pressure: 2200 Pa, viscosity: 7 mPa · s), the same as in Example 1 A wound wrap film having a thickness of 10 μm was produced. The evaluation results of the obtained film are shown in Table 2.

[Comparative Example 7]
A wound wrap film having a thickness of 10 μm was produced in the same manner as in Example 1 except that OcOH (contact angle with the film <10 °, vapor pressure 30 Pa, viscosity 7 mPa · s) was injected into the sock. The evaluation results of the obtained film are shown in Table 2.

[Comparative Example 8]
Liquid in which polyoxyethylene (20) sorbitan monooleate (P20-SMO, Kao-made Rheodor TW-O120V) and water are mixed in a sock at a volume ratio of 0.5% / 99.5% (contact angle with film 59) A wound wrap film having a thickness of 10 μm was produced in the same manner as in Example 1 except that a vapor pressure of 2300 Pa and a viscosity of 1 mPa · s were injected. The evaluation results of the obtained film are shown in Table 2.

[Comparative Example 9]
Except that liquid paraffin (Smoil P-70S manufactured by Matsumura Oil Research Institute) (contact angle with film 10 °, vapor pressure <1 Pa, viscosity 10 mPa · s) and water were injected into the sock, in the same manner as in Example 1. A wound wrap film having a thickness of 10 μm was produced. The evaluation results of the obtained film are shown in Table 2.

  As shown in Table 1 and Table 2, it was shown that the wrap film of each Example was excellent in the balance between adhesiveness and drawability and excellent in transparency. Furthermore, it was shown that the wrap film of each example can maintain excellent adhesion, drawability and transparency even after long-term storage at a high temperature. On the other hand, it was confirmed that the wrap film of each comparative example had at least a good balance between adhesion and drawability, or poor transparency.

  The wrap film of the present invention can be used for various packaging applications including food packaging wrap films.

1 Extruder 2 Circular die 3 Die port 4 Tubular vinylidene chloride resin composition (sock)
5 Sock liquid 6 Cold water tank 7 1st pinch roll 8 Parison 9 2nd pinch roll 10 Bubble 11 3rd pinch roll 12 Double ply film 13 Winding roll

Claims (7)

A film coating agent applied to the surface of a film containing a polyvinylidene chloride-based resin composition,
Including alcohol,
The film coating agent whose contact angle with the said film is 10-25 degrees, and whose vapor pressure in 20 degreeC is 5-1000 Pa.   The film coating agent according to claim 1, which is a sock solution.   The film coating agent according to claim 1 or 2, wherein the alcohol is at least one selected from the group consisting of propylene glycol, isopropanol, 1-butanol, 1-octanol, dipropylene glycol, and tripropylene glycol. The film coating agent according to any one of claims 1 to 3, wherein the alcohol is at least two kinds. A film containing a polyvinylidene chloride resin composition;
The film coating agent according to any one of claims 1 to 4 , which is applied to at least one surface of the film,
Including wrap film. The wrap film according to claim 5 , wherein a coating amount of the film coating agent is 500 to 5000 ppm with respect to a total amount of the film and the film coating agent. Extruding a molten vinylidene chloride resin composition from a die into a tubular shape to obtain a tubular extrudate;
A cooling and solidifying step of storing a liquid containing the film coating agent according to any one of claims 1 to 4 in a hollow portion of the extrudate, and cooling an outer surface of the extrudate with a refrigerant.
Inflating the cooled and solidified extrudate;
A method for producing a wrap film comprising:

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