JP4847698B2 - Stretch film - Google Patents

Description

  The present invention relates to a polyvinyl chloride stretch film used for tray packaging of mushrooms, particularly mushrooms.

  Polyvinyl chloride-based stretch films are used for food packaging such as meat, fresh fish, fruit and mushrooms due to their excellent transparency, gloss, and handling properties, coupled with the widespread use of prepackaging as supermarkets increase. It is used in large quantities as packaging material for packaging. Polyvinyl chloride stretch films are also used for packaging white mushrooms in mushrooms. Mushrooms such as mushrooms have a high moisture content and are fungi, so the respiratory action is active even after packaging, causing discoloration and mold problems, and water drops on the inner surface of the packaged film, reducing the appearance of the product There was a problem to make. In addition, water droplets on the inner surface of the film are said to cause discoloration and decay of mushrooms. In order to solve these problems, it has been proposed to suppress fungal activity and extend the shelf life of mushrooms.

  Patent Document 1 relates to a stretch film for mushrooms in which a mono-, di- or polyglycerin fatty acid ester is added to a synthetic resin film as an inorganic antibacterial agent and an antifogging agent. It is described that it is excellent in cloudiness, transparency and self-adhesiveness. However, when mushrooms are packaged, there is a problem that discoloration of the mushrooms progresses and is not preferable in appearance.

Patent Document 2 relates to a film for packaging mushrooms containing a surfactant of monoglycerin fatty acid ester and / or polyglycerin fatty acid ester, fatty acid dialcohol amine and / or aliphatic dialcohol amine, polyoxyethylene alkyl ether, It is described that the freshness can be preserved for a long period of time, however, when mushrooms are packaged, there is a problem that discoloration of the mushrooms proceeds and this is not preferable in appearance.
JP-A-11-152163 JP 2003-176384 A

  An object of the present invention is to provide a polyvinyl chloride stretch film that has antifogging properties, suppresses discoloration particularly when a mushroom is packaged, and can be stored for a long period of time.

That is, the present invention provides an anti-blocking agent comprising 30 to 45 parts by mass of an adipate ester plasticizer, 5 to 15 parts by mass of epoxidized vegetable oil, diglycerin fatty acid ester and stearic acid monoglyceride with respect to 100 parts by mass of the polyvinyl chloride resin. This is a polyvinyl chloride stretch film comprising 0.5 to 1.5 parts by mass of a clouding agent and a stabilizer. The film according to the present invention has a moisture permeability of 500 to 5000 g / day · m ² and a thickness of 7 to 12 μm. The stretch film of the present invention is excellent for mushroom packaging.

  The present invention suppresses discoloration of mushrooms caused by film additives when mushrooms are packaged with a polyvinyl chloride stretch film, particularly among mushrooms, and improves moisture permeability to remove moisture discharged from mushrooms. It is a polyvinyl chloride stretch film that can suppress the discoloration of mushrooms and extend the shelf life by allowing it to permeate outside.

  The present invention will be described in detail below. The polyvinyl chloride film of the present invention comprises a resin composition in which a plasticizer, an epoxidized vegetable oil, an antifogging agent, and a stabilizer are blended with a polyvinyl chloride resin.

  The polyvinyl chloride resin used in the present invention is preferably a vinyl chloride homopolymer having a polymerization degree of 700 to 1700, or a copolymer mainly composed of vinyl chloride, and a monomer copolymerizable with vinyl chloride. Examples thereof include copolymers with α-olefin, vinylidene chloride, vinyl alcohol, vinyl acetate, acrylic acid, fumaric acid, maleic acid and the like. These vinyl chloride resins may be any of those obtained by a conventionally known polymerization method such as emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization and the like. Among these resins, an ethylene-vinyl chloride copolymer having an ethylene content of 5% or less and a polymerization degree of 1100 to 1400 is more preferable because of its excellent strength as a stretch film.

  The plasticizer used in the present invention is preferably an adipate ester plasticizer. Specific examples include adipic acid-di-isononyl (DINA), adipic acid-di-n-alkyl, adipic acid-di-alkyl. Among them, adipic acid-di-isononyl is preferable because it causes less discoloration when it comes into contact with mushrooms.

  The amount of adipic acid ester plasticizer used in the present invention increases as the amount increases, and the moisture permeability increases. When the mushrooms are tray-wrapped, the water generated by the mushrooms by breathing is discharged out of the packaging container system. can do. Thereby, although the preservability of a mushroom can be maintained for a long time, in the stretch film of this invention, 30-45 mass parts is preferable with respect to 100 mass parts of polyvinyl chloride-type resin. If it is less than 30 parts by mass, sufficient moisture permeability cannot be obtained, and if it is greater than 45 parts by mass, the film becomes too soft.

  The epoxidized vegetable oil used in the present invention has both functions of a plasticizer and a stabilizer. Specifically, epoxidized soybean oil (ESBO), epoxidized linseed oil, and epoxidized safflower oil are preferable. Epoxidized soybean oil is preferred. The addition amount of the epoxidized vegetable oil is preferably 5 to 15 parts by mass with respect to 100 parts by mass of the polyvinyl chloride resin. If it is less than 5 parts by mass, the film has poor thermal stability, and if it exceeds 15 parts by mass, the film becomes too soft.

  The antifogging agent used in the present invention is preferably diglycerin fatty acid ester and stearic acid monoglyceride. In particular, the mass ratio of diglycerin fatty acid ester and stearic acid monoglyceride is preferably 90/10 to 70/30. When the ratio of stearic acid monoglyceride is 10% by mass or less, the film is clouded by moisture discharged from the mushroom of the film. If the ratio of stearic acid monoglyceride is 30% by mass or more, the film becomes cloudy.

  The diglycerin fatty acid ester used in the present invention has antifogging properties when a monoglycerin ester of a saturated or unsaturated fatty acid having 12 to 18 carbon atoms is blended with a polyvinyl chloride resin as compared with other ones. It is preferable because it is easy. Specific examples include diglycerin laurate, diglycerin myristate, diglycerin palmitate, diglyceryl stearate, diglycerin oleate, and diglycerin linoleate.

  The addition amount of the antifogging agent of the present invention is preferably 0.5 to 1.5 parts by mass with respect to 100 parts by mass of the polyvinyl chloride resin. If it is less than 0.5 parts by mass, the film becomes cloudy due to moisture discharged from the mushroom. When the amount exceeds 1.5 parts by mass, the mushroom changes color.

  Stabilizers used in the present invention are calcium salts such as 2-ethylhexylic acid, higher fatty acid, citric acid, gluconic acid, sorbic acid, benzoic acid, isodecanoic acid, neodecanoic acid, and 2-ethylhexylic acid, higher fatty acid, isodecanoic acid, neodecane. Ca-Zn higher fatty acid salts comprising zinc salts such as acids can be mentioned, and these are used alone or in combination of two or more.

  The stabilizer of the present invention should not contain a phosphorus compound. The phosphorus compound moves to the surface of the film, and the mushroom changes color when it comes into contact with the mushroom. Specific examples of the phosphorus compound include trisnonylphenyl phosphite, triphenyl phosphite, diphenyldecyl phosphite, tridecyl phosphite, tris (2-ethylhexyl) phosphite, tristearyl phosphite, 4,4-butylidene (3 -Methyl 6-t-butylphenyl ditridecyl) phosphite, octyl diphenyl phosphite phosphite compound and the like.

The moisture permeability of the film of the present invention is preferably 500 to 5000 g / day · m ² when stored in an environment where the temperature is 40 ° C. and the relative humidity is 90%. When the amount is less than 500 g / day · m ² , moisture discharged from the mushroom when the mushroom is packaged is accumulated between the film and the mushroom, and the mushroom changes color. If it exceeds 5000 g / day · m ² , moisture enters from the outside of the container and the mushroom changes color. When the moisture permeability of the film is within the range of the present invention, the moisture discharged from the mash rule is not accumulated between the films, and the moisture can be appropriately transmitted through the film to suppress discoloration, and the storage period Can be prolonged.

  The thickness of the film of the present invention is preferably 7 to 12 μm. When the thickness is less than 7 μm, the film becomes thin and easily broken. If it exceeds 12 μm, the moisture permeability becomes too low and the mushroom changes color.

  In order to produce the film of the present invention, a publicly known method can be used. That is, after the raw materials are mixed using a known mixer such as a Henschel mixer, a known film forming method such as a T-die extrusion method can be used.

  The method for wrapping the mushrooms of the film of the present invention is not particularly limited, and can be used by a generally performed method. For example, mushrooms which are commodities are put in a tray such as PSP, and the film of the present invention can be wrapped by using a handler upper or an automatic packaging machine.

The following examples further illustrate the present invention. In addition, about the film created by each Example and the comparative example, the characteristic was evaluated by the following method.
(1) Moisture permeability It was performed according to JIS Z0208. The temperature and humidity conditions were as follows.
Condition B Temperature 40 ° C Relative humidity 90%
(2) Mushroom discoloration 200 g of white mushroom was placed in a PSP tray (150 × 200 mm) so as to rise, and overlap-wrapped with the film of each example / comparative example.
The packaged container was stored for 24 hours in an environment at a temperature of 30 ° C. and a relative humidity of 80%, and the degree of discoloration of the mushroom was evaluated according to the index shown in Table 3.
(3) Antifogging property A container packaged in the same manner as in the previous item (2) was stored for 24 hours in an environment of a temperature of 30 ° C. and a relative humidity of 80%, and the degree of fogging of the film was evaluated according to the index shown in Table 3.

Example 1
100 parts by weight of a PVC resin having a polymerization degree of 1300 (TE-1300 manufactured by Taiyo PVC Co., Ltd.), 35 parts by weight of DINA, 10 parts by weight of ESBO, 0.8 part by weight of diglycerin oleate as an antifogging agent, and 0 stearic acid monoglyceride After adding 2 parts by weight and 1 part by weight of Ca-Zn higher fatty acid salt as a qualifying agent and kneading with a Henschel mixer, using a screw of L / D = 28 with a 65 mm single screw extruder manufactured by Toshiba Machine, die width Using a T die of 550 mm and a die lip of 0.7 mm, a polyvinyl chloride film having a thickness of 11 μm and a width of 300 mm was obtained at a set temperature of 170 ° C. to 200 ° C. at a take-up speed of 50 m / min.

(Example 2-4)
According to the recipe shown in Table 1, a polyvinyl chloride film was obtained in the same manner as in Example 1.

(Comparative Example 1-4)
A polyvinyl chloride film was obtained in the same manner as in Example 1 except that the blending ratio of the raw materials was changed to Table 2.

(Comparative Example 5)
As in Example 1, except that 0.8 parts by mass of Ca-Zn higher fatty acid salts and 0.2 parts by mass of 4,4-butylidene (3-methyl 6-tert-butylphenylditridecyl) phosphite were used as stabilizers. Thus, a polyvinyl chloride film was obtained.

  In Examples 1 to 4, no mushroom discoloration was observed under the conditions of 30 ° C., 80% relative humidity, and 24 hours, whereas in other comparative examples except Comparative Example 3, some mushrooms were used. The discoloration of was seen. In Comparative Example 3, although no mushroom discoloration was observed, non-uniform adhesion of water droplets was observed.

Claims (3)

An antifogging agent composed of 30 to 45 parts by mass of an adipate ester plasticizer, 5 to 15 parts by mass of an epoxidized vegetable oil, diglycerin fatty acid ester and stearic acid monoglyceride is added to 100 parts by mass of the polyvinyl chloride resin. A polyvinyl chloride stretch film composed of 5-1.5 parts by mass and a stabilizer not containing a phosphorus compound , and the moisture permeability of the film in condition B according to JIS Z0208 is 500-5000 g / day · m ² . Polyvinyl chloride stretch film . The polyvinyl chloride stretch film according to claim 1, wherein the film has a thickness of 7 to 12 μm. The polyvinyl chloride stretch film for mushroom packaging according to claim 1 or 2 .