JP2520361B2 - Vinyl chloride stretch film for food packaging - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vinyl chloride stretch film for food packaging, which has antibacterial and antifungal properties.

[0002]

2. Description of the Related Art Ultrathin soft films (0.008 to 0.02 mm) made of vinyl chloride resin have hitherto been widely used as a film for packaging foods such as fruits and vegetables and marine products because the film itself has an adhesive property. There is. It is also known that an antibacterial agent is added to the vinyl chloride resin forming this film to impart antibacterial and antifungal properties to the film. An organic compound is often used as the antibacterial agent, and examples of the organic compound include binarazine which is an organic arsenic compound, PCP which is an organic chlorine compound, and thiabenzole which is a derivative of aniline. It is said that these have elution properties from resins and have a safety and hygiene problem in food packaging applications due to their odor, antibacterial and antifungal persistence, and stability. As an inorganic antibacterial agent developed in recent years, there is an antibacterial silver zeolite in which metal ions in zeolite are replaced with silver ions, but since it is an inorganic antibacterial agent, it has excellent durability, elution, odor, and heat resistance. Cage,
It can be used in a stable state. However, when a silver compound such as an antibacterial silver zeolite is added to a vinyl chloride resin to form a film, sheet, etc., the film, sheet, etc. will be significantly discolored by light, and the commercial value will be increased. It was the one that lowered.

A specific phosphoric acid compound has recently been announced as an antibacterial agent which further improves the discoloration of the antibacterial agent made of silver zeolite (see Japanese Patent Laid-Open No. 4-275370). The publication describes a case where the above specific phosphoric acid compound is blended with polyethylene. However, when this compound is blended with a vinyl chloride resin, since the compound contains silver ions, the conventional silver zeolite is used. Although it is improved as compared with the above case, it may not be said to be sufficient because it may cause discoloration due to light as in the case of the conventional antibacterial silver zeolite.

[0004]

DISCLOSURE OF THE INVENTION The present inventors have overcome the above-mentioned problems of the prior art and have excellent antibacterial and antifungal properties with improved photochromic properties and excellent antibacterial properties with no hygiene problems. As a result of intensive studies to develop a stretch film for food packaging, the present invention has been completed. The purpose of the present invention is to prevent discoloration due to irradiation of light, and to have antibacterial / antifungal properties suitable for food packaging. The present invention provides a vinyl chloride stretch film having

[0005]

SUMMARY OF THE INVENTION The gist of the present invention is to add 0.2 to 0.5 parts by weight of a phosphate compound represented by the following general formula to 100 parts by weight of a vinyl chloride resin and a fatty acid. Stabilizer composed of calcium salt and fatty acid zinc salt
It is a vinyl chloride stretch film for food packaging (hereinafter, simply referred to as a film), which is characterized by containing 05 to 1 part by weight. AgaAbMc (PO ₄ ) d · nH ₂ O (1) (In the formula, A is at least one ion selected from alkali metal ions, alkaline earth metal ions, ammonium ions or hydrogen ions, and M is a tetravalent metal. And
n is a number satisfying 0 ≦ n ≦ 6, a and b are both positive numbers, and c and d are c = 2 and a = d when a + mb = 1.
3, when a + mb = 2, c = 1 and d = 2. However, m
Is the valence of A. )

That is, according to the present invention, the calcium salt and the zinc salt of a fatty acid are blended as a stabilizer together with the above-mentioned phosphate compound, so that the optical effect is increased as compared with the case where other stabilizers are blended due to their additive effect. It does not cause discoloration and has an extremely excellent effect. The reason why the film of the present invention improves the photochromic property is not clear, but HC in which the fatty acid calcium salt and the fatty acid zinc salt are separated from the vinyl chloride resin
l in order to neutralize HCl and to exchange C1 ions by ion exchange and take them into the structure for inactivation.
It seems that it works effectively to prevent the formation of silver compounds such as the formation of gCl.

Hereinafter, the present invention will be described in detail. The stretch film of the present invention is made of a vinyl chloride resin by a usual method, for example, an extrusion method or a casting method, and is stretched by about 1.05 to 3 times to a thickness of 0.008 to 0.
It is about 02 mm. And, as the vinyl chloride resin that can obtain this film, polyvinyl chloride or vinyl chloride monomer and other monomers such as ethylene, propylene, alkyl vinyl ether, vinylidene chloride, acrylic acid ester, vinyl acetate, Examples thereof include copolymers with methacrylic acid esters and acrylonitrile, and blends of polyvinyl chloride with other polymers.

The compound that can be used as an antibacterial agent in the present invention is a compound represented by the following general formula (1). AgaAbMc (PO ₄ ) d · nH ₂ O (1) (A is an alkali metal ion, an alkaline earth metal ion,
It is at least one kind of ion selected from ammonium ion or hydrogen ion, M is a tetravalent metal, n is a number satisfying 0 ≦ n ≦ 6, a and b are both positive numbers, and c and d is a + mb = 1, c = 2, d =
3, when a + mb = 2, c = 1 and d = 2. However,
m is the valence of A. )

The compound represented by the general formula (1) is a
When + mb = 1, the compound is an amorphous compound or a crystalline compound belonging to the space group R3c having coefficients of c = 2 and d = 3, and each constituent ion represents a compound forming a three-dimensional network structure, and a + mb = 2. In the case of, it represents a compound having a coefficient of c = 1 and a coefficient of d = 2, in which amorphous or each constituent ion forms a layer state.

The phosphate compound used in the present invention has a slight discoloration when exposed to sunlight, and therefore satisfies the formula a + mb = 1 and has a three-dimensional mesh having coefficients c = 2 and d = 3. Crystalline compounds having a lamellar structure are preferred.

A in the general formula (1) is at least one ion selected from an alkali metal ion, an alkaline earth metal ion, an ammonium ion and a hydrogen ion. Preferred specific examples are lithium, sodium and potassium. There is an alkali metal ion such as, and an alkaline earth metal ion such as magnesium or calcium or hydrogen ion, and among these, lithium, sodium, ammonium ion and hydrogen ion are preferable from the viewpoint of stability of the compound and availability at low cost. Ion.

In the compound represented by the above general formula (1) and the composition containing the compound, in order to exert a high degree of light resistance, hydrogen ions and alkali metal ions may be used as the constituent ions of A ions. preferable.

M in the above general formula (1) is a tetravalent metal, and preferable specific examples thereof include zirconium, titanium or tin. Considering the stability of the compound, zirconium and titanium are particularly preferable tetravalent metals. It is a metal.

The following are specific examples of the phosphate compound of the general formula (1). Ag _0.005 Li _0.995 Zr ₂ (PO ₄ ) ₃ Ag _0.01 (NH ₄ ) _0.99 Zr ₂ (PO ₄ ) ₃ Ag _0.05 Na _0.95 Zr ₂ (PO ₄ ) ₃ Ag _0.2 K _0.8 Ti ₂ (PO ₄ ) ₃ Ag _0.1 H _0.9 Zr ₂ (PO ₄ ) ₃ Ag _0.001 Li _1.999 Zr (PO ₄ ) ₂ Ag _0.01 Na _1.99 Zr (PO ₄ ) ₂ Ag _0.01 K _1.99 Sn (PO ₄ ) ₂ 1.2H ₂ O Ag _0.1 (NH ₄ ) _{1.9 Ti (PO 4) 2 ·} 2H 2 O Ag 0.02 H 1.98 Zr (PO 4) 2 · 1.7H 2 O Ag 0.01 H 0.95 Li 0.04 Zr 2 (PO 4) 3 Ag 0.05 H 0.85 Li 0.10 Zr 2 (PO ₄ ) ₃ Ag _0.10 H _0.80 Li _0.10 Ti ₂ (PO ₄ ) ₃ Ag _0.15 H _0.60 Li _0.25 Zr ₂ (PO ₄ ) ₃ Ag _0.50 H _0.40 Li _0.10 Ti ₂ (PO ₄ ) ₃ Ag _0.92 H _0.05 Li _0.03 Zr ₂ (PO ₄ ) ₃ Ag _0.05 H _0.55 Na _0.40 Zr ₂ (PO ₄ ) ₃ Ag _0.10 H _0.60 N a _0.30 Zr ₂ (PO ₄ ) ₃ Ag _0.20 H _0.75 Na _0.05 Ti ₂ (PO ₄ ) ₃ Ag _0.30 H _0.45 Na _0.25 Zr ₂ (PO ₄ ) ₃ Ag _0.35 H _0.60 Na _0.05 Sn ₂ (PO ₄ ) ₃ Ag _0.50 H _0.45 K _0.05 Sn ₂ (PO ₄ ) ₃ Ag _0.70 H _0.25 k _0.05 Ti ₂ (PO ₄ ) ₃

As the method for synthesizing the phosphate compound used in the present invention, there are a calcination method, a wet method, a hydrothermal method and the like, and any method can be used for production. Particularly in the present invention, a phosphate-based compound produced by a wet method is preferable, and a phosphate-based compound obtained by a wet method is particularly preferable.
What was baked at 00 to 1300 ° C is preferable. Through this baking step, the chemical and physical stability of the antibacterial agent can be remarkably improved, and an antibacterial agent excellent in light resistance can be obtained. Baking at a temperature lower than 500 ° C. makes it difficult to sufficiently exert the effect of improving the chemical and physical stability of the antibacterial agent, and baking at a temperature higher than 1300 ° C. may reduce the antibacterial property. is there.

The firing time is not particularly limited, but usually 1-2.
The effect of the present invention can be sufficiently exhibited by firing for 0 hours. The temperature rising rate and the temperature rising rate are also not particularly limited, and can be appropriately adjusted in consideration of the capacity and productivity of the firing furnace.

In order to exhibit antifungal, antibacterial and antialgal properties, the larger the value of a in the general formula (1) is, the better.
When the value is 0.001 or more, it is possible to sufficiently exhibit antifungal properties, antibacterial properties, and antialgal properties. However, if the value of a is less than 0.001, it may be difficult to exert antifungal, antibacterial and antialgal properties for a long time.
The value of a is preferably 0.01 or more. or,
Considering economic efficiency, the value of a is preferably 0.5 or less. The preferred specific properties of these antibacterial agents are true specific gravity of 3.
0, the bulk specific gravity is 0.25, and the average particle size is 0.
It is 2 to 0.8 μm.

The film of the present invention comprises a vinyl chloride resin 1
The phosphate compound represented by the general formula (1), which is an antibacterial agent, is contained in an amount of 0.2 to 0.5 parts by weight with respect to 00 parts by weight. It cannot be expected, and if it is 0.5 parts by weight or more, no difference due to the added amount is found, and the amount is excessive.

Further, in the present invention, as the stabilizer,
Use fatty acid calcium salt and fatty acid zinc salt. The amount added is 0.0 with respect to 100 parts by weight of vinyl chloride resin.
It is 5 to 1 parts by weight, and if it is 0.05 parts by weight or less, sheet processing is impossible, and at the same time, the effect of preventing discoloration due to light is insufficient, and if it is 1 parts by weight or more, transparency becomes poor. It will decrease. The ratio of the fatty acid calcium salt and the fatty acid zinc salt is preferably about the same amount or about 10:15, and the zinc salt is preferably added in a slightly larger amount.

The vinyl chloride resin composition for forming the film of the present invention contains, in addition to the essential components in its formulation, an amount of a plasticizer, a stabilizer, an antifogging agent, etc. depending on the intended use of the film.
A metal stabilizer, an anti-coloring agent, an antioxidant, an antistatic agent, an ultraviolet absorber, a lubricant and the like are optionally mixed. Further, other ingredients such as metal soaps and organic phosphite compounds can be used within the usual range depending on the required quality.

Examples of the plasticizer include di-n-octyl phthalate, di-2-ethylhexyl phthalate, dibutyl phthalate, diisononyl phthalate, butylbenzyl phthalate, dilauryl phthalate, diheptyl phthalate.
Phthalates such as dimethyl phthalate, diisodecyl phthalate, dioctyl phthalate and dicyclohexyl phthalate, dioctyl adipate, diisodecyl adipate, diisononyl adipate (referred to as DINA) ,
Di (n having a linear alkyl group having 6, 8, 10 carbon atoms
-Hexyl, n-octyl, n-decyl) adibate (trade name 610A), di (i-heptyl) having a linear and / or side chain alkyl group having 7 or 9 carbon atoms,
adipic acid such as i-nonyl) adipate, di-i-butyl azelate, di-n-hexyl azelate, azelaic acid such as di-i-octyl azelate, diethylene glycol dibenzoate, etc. Benzoic acid type, dibutyl fumarate, dioctyl fumarate, fumaric acid type such as diphenoxyethyl fumarate, butyl laurate, lauric acid type such as ethylene glycol monoethyl ether laurate, pentaerythritol tetraacetate etc. Pentaerythritol-based, silylol-based such as methyl altyl-silinolate, sebacic-acid-based such as dimethyl sebacate, citric-acid-based such as acetyltributyl citrate, glyceryl ester such as glyceryl monolauryl diacetate, etc. Polyester etc. can be raised. The plasticizer used in the present invention is used for imparting flexibility to the molded product, and the addition amount is not limited, but is preferably 20 parts by weight or more.

The stabilizer used in the present invention is a stabilizer composed of a fatty acid calcium salt and a fatty acid zinc salt, but other stabilizers such as an epoxy stabilizer may be used. Epoxy stabilizers include epoxidized vegetable oils such as epoxidized soybean oil and epoxidized linseed oil, and epoxy resins. Regarding the amount of addition, it is possible to add the required amount depending on the film formation method.

Further, an organic stabilizer may be added.
Examples of organic stabilizers include trisnonylphenylphosphite, triphenylphosphite, diphenyldecylphosphite, tridecylphosphite, and tris (2-
Examples thereof include ethylhexyl) phosphite, tristearylphosphite, and octyldiphenylphosphite phosphite compounds. The addition amount of these compounds is preferably 0.01 to 10 parts by weight, more preferably 0.05 to 5 parts by weight.

As the lubricant, an aliphatic acid lubricant such as isostearic acid, stearic acid and palmitic acid, a fatty acid amide lubricant such as stearic acid amide and methylenebis stearamide, and an ester lubricant such as butyl stearate. , Polyethylene wax, liquid paraffin, higher alcohol and the like.

Examples of antioxidants include phenolic antioxidants, aliphatic sulfides, disulfides, and thiodipropionic acid esters. In the present invention, an antifogging agent may be added depending on the purpose of use. As the antifogging agent, glycerin-based ester, polyether or the like can be used. Preferred compounding agents to be added to the vinyl chloride resin that can obtain the film of the present invention are mainly trisnonylphenyl phosphite, in addition to the above-mentioned antibacterial agent and stabilizer consisting of fatty acid calcium and fatty acid zinc. Organic stabilizers composed of organic acids and organic acid esters and other auxiliaries.

[0026]

EXAMPLES Examples and comparative examples of specific embodiments of the present invention will be described in detail below. Example 1 100 parts by weight of a vinyl chloride resin was compounded with a predetermined amount of each compounding agent as shown in the following compounding table 1, dried up with a super mixer and then a thickness of 0. 0
It was extruded into a 15 mm film and cut into a square having a side of about 8 cm to obtain a test piece. This was subjected to an antibacterial activity test.

Recipe 1 Vinyl chloride resin 100 parts by weight Diisononyl adipate (DINA) 28 parts by weight Di (n-hexyl, n-octyl, n-decyl) adipate (trade name 610A) 4 parts by weight Epoxy Soybean oil 10 parts by weight Stabilizer (Note ¹ ) 1 part by weight Ag _0.10 H _0.40 Na _0.50 Zr ₂ (PO ₄ ) _{30 to} 0.43 parts by weight Glycerin ester / polyether (antifog agent) 3 parts by weight Note ¹ Stabilizer consists of the following components. Fatty acid calcium 11% Fatty acid zinc 14% Trisnonylphenyl phosphite 45% Organic acids and organic acid esters Residual

As an evaluation of the obtained test piece, an antibacterial activity test was conducted. For the antibacterial activity test, Escherichia coli and Staphylococcus aureus were used as test bacteria, which were shake-cultured in ordinary broth medium (Eiken Chemical Co., Ltd.) at 35 ° C for 6 hours to prepare a culture solution of the test bacteria, which was sterilized. With phosphate buffer, 20,000
It was diluted 0 times to obtain a bacterial solution. 1 ml of the bacterial solution was dropped on the test piece, stored at 25 ° C., and the viable cell count after each time was measured. To measure the viable cell count, wash out with 10 ml of SCDL liquid medium, and use the standard agar culture medium (Eiken Chemical Co., Ltd.) for this washout solution to measure the viable cell count by the pour plate culture method (35 ° C, 2 days culture). Then, it was converted per one test piece. Table 1 shows the results.

[0029]

[Table 1]

In Table 1, "<10" indicates that no bacterium was detected, and "control" means that the same amount of bacterium as the sample was used in the dish. It shows the case of saving in. Example 2 100 parts by weight of vinyl chloride resin was mixed with a prescribed amount of each compounding agent as shown in the following Table 2, and after kneading in the same manner as in Example 1, the thickness was adjusted to 0. 015
The film was extruded into a film having a size of mm and subjected to a color change test.

Recipe 2 Vinyl chloride resin 100 parts by weight Plasticizer 32 parts by weight Epoxidized soybean oil 10 parts by weight Fatty acid salt stabilizer 0.5 parts by weight Ag _0.10 H _0.40 Na _0.50 Zr ₂ (PO ₄ ) ₃ 0.36 parts by weight Department

In the discoloration test, the product was exposed to sunlight at room temperature for 3 days, and the degree of discoloration was evaluated by the naked eye in the following three stages. The results are shown in Formulation Table 3.

Recipe 3 Fatty acid salt type Discoloration Calcium stearate / Zinc stearate No discoloration Calcium stearate Almost no discoloration Zinc stearate Almost no discoloration Cadmium stearate Discoloration Barium stearate Discoloration Lead stearate Discoloration

[0034]

As described above, according to the present invention, an antibacterial agent of a specific phosphate compound and a stabilizer composed of a fatty acid calcium salt and a fatty acid zinc salt are added to 100 parts by weight of a vinyl chloride resin. By combining, a film having excellent antibacterial properties as shown in Table 1 was obtained, and the film was stable to light as shown in Table 4.

Front page continuation (72) Inventor Koji Sugiura 1-1 Funami-cho, Minato-ku, Nagoya, Aichi Toagosei Chemical Industry Co., Ltd. Nagoya Research Institute (72) Inventor Hideki Kato 1 Funami-cho, Minato-ku, Nagoya, Aichi No. 1 Toagosei Chemical Industry Co., Ltd. Nagoya Research Institute

Claims (1)

(57) [Claims] 1. A phosphate compound represented by the following general formula (1) is added to 100 parts by weight of a vinyl chloride resin.
A vinyl chloride stretch film for food packaging, comprising 2 to 0.5 part by weight and 0.05 to 1.0 part by weight of a stabilizer composed of a fatty acid calcium salt and a fatty acid zinc salt. AgaAbMc (PO ₄ ) d · nH ₂ O (1) (In the formula, A is at least one ion selected from alkali metal ions, alkaline earth metal ions, ammonium ions or hydrogen ions, and M is a tetravalent metal. And
n is a number satisfying 0 ≦ n ≦ 6, a and b are both positive numbers, and c and d are c = 2 and a = d when a + mb = 1.
3, when a + mb = 2, c = 1 and d = 2. However, m
Is the valence of A. )