JPH0812835A - Polyvinyl chloride-based stretch film - Google Patents

Abstract

PURPOSE:To obtain a polyvinyl chloride-based stretch film suitable for packaging a food, distributed, preserved and sold in a frozen or a refrigerated state. CONSTITUTION:This polyvinyl chloride-based stretch film is obtained by mixing 100 pts.wt. polyvinyl chloride-based resin with 25-45 pts.wt. plasticizer and 2.0-4.0 pts.wt. antifogging agent. The plasticizer comprises (1) an adipic acid ester-based plasticizer having a >=9C alkyl group and (2) a mixed adipic acid ester-based plasticizer prepared by reacting two or more kinds of aliphatic alcohols having a <=10C alkyl group with adipic acid. The amount of the added plasticizer (1) is within the range of 40-80wt.% based on the total amount of the added plasticizers (1) and (2). The antifogging agent comprises (a) an antifogging agent selected from the group consisting of glycerol esters of fatty acids and sorbitan esters thereof and (b) a polyoxyethylene alkyl ether. The amount of the added antifogging agent (a) is within the range of 1.5-2.5 pts.wt. and that of the added polyoxyethylene alkyl ether (b) is within the range of 0.5-1.5 pts.wt.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyvinyl chloride stretch film used for the packaging of articles and the like, and particularly has excellent low temperature strength and low temperature anti-fog property, and can be distributed in a frozen state or a refrigerated state. The present invention relates to a polyvinyl chloride stretch film suitable for packaging foods that are stored and sold.

[0002]

2. Description of the Related Art Polyvinyl chloride stretch films are characterized by their excellent transparency, gloss, and handling properties, along with the widespread use of pre-packaging accompanying the increase in supermarkets, such as meat, fresh fish, fruits and vegetables, and side dishes. It is widely used as a packaging material for pre-packaging for food packaging.

[0003] In recent years, the freshness preservation, long-term preservation, and convenience have been improved against the backdrop of consumers' growing awareness of food freshness due to gourmet taste, the development of cold chains, and the reduction of housework time associated with the increase of women's social advancement. From the viewpoints such as the above, the distribution, storage, and sale of food in the frozen state or the refrigerated state are rapidly increasing.

The freezing and refrigerating temperature ranges are such that the freezing is -18 ° C or lower, specifically about -30 ° C to -20 ° C, and the refrigerating is -2 ° C to 10 ° C, specifically-. Two
It is in the range of about 5 ° C to 5 ° C. Some of these foods are maintained in a frozen state or a refrigerated state consistently from distribution / preservation to sales, while other foods are kept in a frozen state for distribution / preservation and sold in a refrigerated state.

Distribution in frozen state and / or refrigerated state
A film for packaging foods to be stored and sold is required to have both low temperature strength and low temperature anti-fogging property. Low temperature strength refers to the ability to withstand vibrations and shocks during distribution and storage in the freezing temperature range, to protect the object to be packaged without breaking the film into glass and without losing its flexibility. Further, the low-temperature antifogging property refers to a performance in which, in the refrigerating temperature range, the moisture contained in the food to be packaged does not condense on the film surface and the film can be clearly seen without clouding.

Various materials having such low temperature strength and low temperature antifogging property have been proposed. As those to which low temperature strength is imparted, those using an adipic acid ester type plasticizer and a polyester type plasticizer (JP-A-60-17)
No. 9441), those using an adipic acid ester plasticizer and dibutyl sebacate and / or acetyltributyl citrate (Japanese Patent Publication No. 1-57696).

The low temperature anti-fog property is given as follows.
Using a mixture of sorbitan monooleate and glycerin monobehenate as a low HLB surfactant and a mixture of sorbitan monolaurate and polyoxyethylene glyceryl monostearate as a high HLB surfactant (Japanese Patent Publication No. 52-42820) JP-A-59-213749) and the like which use polyoxyethylene alkyl ether, sorbitan fatty acid ester and aliphatic diethanolamide. As a stretch film other than the polyvinyl chloride resin, a stretch film using a polyolefin resin is commercially available.

[0008]

However, in the conventional and those described above, in the refrigerating temperature range, the film withstands vibration and shock during distribution and storage, and the film is broken into glass and loses flexibility. However, in the freezing temperature range, it may not be able to withstand vibration and shock during distribution and storage, and the film may break into glass or lose its flexibility. They could not protect the objects and could not maintain the low temperature strength, and the loss in distribution, storage and sale and the cost required for repacking were great.

Further, in the above conventional and,
Inconvenience that low-temperature anti-fog property is not sufficiently imparted, moisture contained in food to be packaged is condensed on the film surface, the product to be packaged does not look clear, and the commercial value at the time of sale is significantly reduced. was there.

Further, in a stretch film using a polyolefin resin other than polyvinyl chloride resin,
Although it has excellent low-temperature strength, it has the drawback of being inferior in low-temperature antifogging property, transparency and gloss. Moreover, the price is extremely higher than that of the polyvinyl chloride stretch film, and there is a drawback that the cost of users such as supermarkets and food processing manufacturers increases.

The present invention solves the above-mentioned conventional problems, and withstands vibration and shock during distribution and storage in the temperature range of freezing, and the film does not break into glass,
Low temperature strength that can protect the packaged object without losing flexibility, and in the refrigeration temperature range, the moisture contained in the food that is the packaged object does not condense on the film surface and the film is clear and the packaged object is clear. It is an object of the present invention to provide a polyvinyl chloride-based stretch film which is excellent in low-temperature anti-fog properties and which is suitable for packaging foods that are distributed, stored and sold in a frozen state and / or a refrigerated state.

[0012]

Means for Solving the Problems As a result of intensive studies in view of the above-mentioned conventional problems, the present inventor added a specific plasticizer in a specific ratio in a specific amount, and further added a specific antifogging agent. It was found that a film excellent in low temperature strength and low temperature anti-fog property can be obtained by adding a specific amount, and finally the present invention was completed.

That is, the present invention is a polyvinyl chloride resin obtained by mixing 25 to 45 parts by weight of a plasticizer and 2.0 to 4.0 parts by weight of an antifogging agent with 100 parts by weight of a polyvinyl chloride resin. A stretch film, wherein the plasticizer is (1)
An adipic acid ester-based plasticizer having an alkyl group having 9 or more carbon atoms, and (2) a mixed adipic acid ester-based resin obtained by the reaction of two or more aliphatic alcohols having an alkyl group having 10 or less carbon atoms with adipic acid The plasticizer (1) is added in an amount of 40 to 80% by weight based on the total amount of plasticizers (1) and (2), and the antifogging agent is glycerin fatty acid ester. And an antifogging agent selected from the group consisting of sorbitan fatty acid ester, and polyoxyethylene alkyl ether, and the addition amount is 1.5 to 2.5 parts by weight, and the addition amount is 0.5 to 1. The gist of the present invention is to provide a polyvinyl chloride stretch film characterized by being in the range of 5 parts by weight.

The polyvinyl chloride stretch film of the present invention will be described in detail below. The polyvinyl chloride resin used in the stretch film of the present invention is a vinyl chloride homopolymer having a degree of polymerization of 700 to 1700, preferably a vinyl chloride homopolymer having a degree of polymerization of 1300, or mainly vinyl chloride. The copolymer may be a monomer copolymerizable with vinyl chloride, for example,
α-olefin, vinylidene chloride, vinyl alcohol,
Examples thereof include copolymers with vinyl acetate, acrylic acid, fumaric acid, maleic acid and the like. Any of these vinyl chloride-based resins may be used as long as it is obtained by a conventionally known polymerization method such as emulsion polymerization, suspension polymerization, solution polymerization and bulk polymerization.

The addition amount of the plasticizer used in the present invention is
It is determined depending on the easiness of elongation of the film required at the time of packaging work, but is in the range of 25 to 45 parts by weight with respect to 100 parts by weight of the polyvinyl chloride resin. If this range is less than 25 parts by weight, flexibility and self-adhesiveness cannot be obtained, and if it exceeds 45 parts by weight, it becomes too soft, which is not preferable.

As the plasticizer in the present invention, it is necessary to jointly use two kinds of plasticizers having a specific composition, one of which is (1) an adipic acid ester plasticizer having an alkyl group having 9 or more carbon atoms, and the other. One type is (2) a mixed adipic acid ester plasticizer obtained by reacting two or more aliphatic alcohols having an alkyl group having 10 or less carbon atoms with adipic acid.

Specific examples of the plasticizer (1) include diisononyl adipate (DINA, carbon number of alcohol = 9) and diisodecyl adipate (DIDA, carbon number of alcohol = 10). Then, diisononyl adipate is particularly preferable. The plasticizer (1) has an effect of promoting bleed-out of the antifogging agent,
This improves the low temperature anti-fog property.

The plasticizer (2) is a combination of two or more aliphatic alcohols of n-hexyl alcohol, n-heptyl alcohol, n-octyl alcohol, n-nonyl alcohol and n-decyl alcohol and adipic acid. A plasticizer obtained by a reaction or the like. Specific examples thereof include _C8,10 adipate, _C7,9 adipate, and _C6,8,10 adipate. Among these, _C6,8,10 adipate is preferable. The plasticizer (2) has the effect of improving the flexibility of the film in the freezing temperature range, thereby improving the low temperature strength.

In the stretch film of the present invention, the above-mentioned two types of plasticizers are used in combination and added in a specific ratio in a specific ratio. The addition amount of the plasticizer in the above (1) is (1) and (2). 40-80% by weight based on the total amount of plasticizer added
It is important to be in the range of, and more preferably 45 to
It is in the range of 75% by weight, more preferably 50 to 70.
It is in the range of% by weight.

When the added amount of the plasticizer of (1) is less than 40%, the bleed-out promoting effect of the antifogging agent of the plasticizer of (1) is not sufficiently imparted, and the softness of the plasticizer of (2) is Although the effect of improving the property is sufficiently imparted and the low temperature strength is satisfied, the low temperature anti-fogging property is not improved. Also, (1)
If the added amount of the plasticizer of (1) exceeds 80% by weight, the bleed-out promoting effect of the antifogging agent of the plasticizer (1) is sufficiently imparted and the low temperature antifogging property is improved, but the plasticization of (2) The effect of improving the flexibility of the agent is not sufficiently imparted, and the low temperature strength is not satisfied.

On the other hand, the amount of plasticizer added in (1) is 40 to 40 relative to the total amount of plasticizer added in (1) and (2).
Only in the case of the range of 80% by weight, both the bleed-out promoting effect of the antifogging agent possessed by the plasticizer of (1) and the effect of improving the flexibility of the film possessed by the plasticizer of (2) are imparted, and Withstands vibration and shock during distribution and storage in the temperature range of, and the film does not break into glass,
Further, it is possible to obtain a film which is excellent in low-temperature strength capable of protecting an object to be packaged without losing flexibility and which is sufficiently imparted with an effect of improving low-temperature anti-fog property in a refrigerating temperature range.

Next, the amount of the antifogging agent added to the stretch film of the present invention is 100% by weight of the polyvinyl chloride resin.
It is in the range of 2.0 to 4.0 parts by weight with respect to parts by weight. If this range is less than 2.0 parts by weight, low-temperature anti-fog properties will not be sufficiently imparted, and there will be a problem that water contained in the food to be packaged will condense on the film surface. If the amount exceeds the range, the low-temperature antifogging property will not be further improved even if the amount is added, and the bleed-out of the antifogging agent will be excessive and the transparency of the film will be significantly impaired, which is not preferable.

As the antifogging agent in the present invention, it is necessary to use two kinds of antifogging agents having a specific composition in combination, one of which is an antifogging agent selected from the group consisting of glycerin fatty acid ester and sorbitan fatty acid ester, The other type is polyoxyethylene alkyl ether.

Examples of the antifogging agent include monoglycerin fatty acid ester, polyglycerin fatty acid ester and sorbitan fatty acid ester. This monoglycerin fatty acid ester has 12 carbon atoms.
Monoglycerin esters of ~ 18 saturated or unsaturated fatty acids are preferred. Specific examples thereof include monoglycerin laurate, monoglycerin myristate, monoglycerin palmitate, monoglycerin stearate, monoglycerin oleate, and monoglycerin linoleate.

As the polyglycerin fatty acid ester,
A polyglycerin ester of a saturated or unsaturated fatty acid having 12 to 18 carbon atoms is preferable, specifically, polyglycerin laurate, polyglycerin myristate, polyglycerin palmitate, polyglycerin stearate, polyglycerin oleate, polyglycerin. Examples include linoleate.

The sorbitan fatty acid ester is preferably a sorbitan ester of a saturated or unsaturated fatty acid having 12 to 18 carbon atoms. Specific examples include sorbitan laurate, sorbitan myristate, sorbitan palmitate, sorbitan stearate, sorbitan oleate, and sorbitan linoleate. Among the above compounds, monoglycerin laurate, monoglycerin oleate, monoglycerin linoleate, polyglycerin laurate, polyglycerin oleate, polyglycerin linoleate, sorbitan laurate, sorbitan oleate, sorbitan linoleate are preferred, and more Preferably, monoglycerin laurate, monoglycerin oleate, polyglycerin laurate, polyglycerin oleate, sorbitan laurate, sorbitan oleate, more preferably monoglycerin oleate, polyglycerin oleate, sorbitan oleate, these are, They may be used alone or in combination of two or more.

The polyoxyethylene alkyl ether, which is the antifogging agent, has 12 to 12 carbon atoms.
A compound selected from the group consisting of polyoxyethylene alkyl ethers of saturated alcohol of 18 is preferable, and more preferably, the number of added moles of ethylene oxide is 3 to 7.
Is a polyoxyethylene alkyl ether. Specific examples thereof include polyoxyethylene lauryl ether, polyoxyethylene myristyl ether, polyoxyethylene palmityl ether, and polyoxyethylene stearyl ether. Among these, polyoxyethylene lauryl ether is particularly preferable.

In the stretch film of the present invention, it is important that the above two kinds of antifogging agents are used in combination and the addition amount of each is within a specific range. First, the addition amount of the anti-fog agent is
1.5 to 100 parts by weight of polyvinyl chloride resin
It is in the range of 2.5 parts by weight, and if it is less than 1.5 parts by weight, the moisture contained in the food is condensed on the film surface, and the low temperature antifogging property is not satisfied. On the other hand, if the amount exceeds 2.5 parts by weight, the water contained in the food does not condense on the film surface, but since these compounds form micelles on the film surface, the water film becomes uniform. Of course, this part becomes a lens shape, and the appearance of the product is significantly deteriorated.

The amount of the antifogging agent added is in the range of 0.5 to 1.5 parts by weight with respect to 100 parts by weight of the polyvinyl chloride resin. The effect of forming a uniform water film is not provided. On the other hand,
The addition of more than 1.5 parts by weight does not further improve the effect of forming a uniform water film, so it is not necessary to add more than 1.5 parts by weight.

Therefore, in the present invention, 1.5 to 2.5 parts by weight of the antifogging agent and 0.5 to 1.
Only when 5 parts by weight is added, the water contained in the food to be packaged does not condense on the film, and
By forming an extremely uniform water film on the film, low-temperature antifogging property is sufficiently imparted. Moreover, due to the effect of the plasticizer (1), bleed-out of these antifogging agents is promoted, and extremely good low temperature antifogging properties are imparted.

In the present invention, in addition to the resin, plasticizer and antifogging agent shown above, stabilizers, lubricants and the like can be optionally blended. As the stabilizer to be blended in the present invention, epoxidized oils such as epoxidized soybean oil, epoxidized linseed oil, and epoxidized safflower oil; 2-ethylhexylic acid, higher fatty acid, citric acid, gluconic acid, sorbic acid, Examples include Ca-Zn higher fatty acid salts consisting of calcium salts such as benzoic acid, isodecanoic acid and neodecanoic acid and zinc salts such as 2-ethylhexylic acid, higher fatty acid, isodecanoic acid and neodecanoic acid, and one or more of them. Used in combination.

The lubricant to be blended in the present invention has 8 to 2 carbon atoms such as lauric acid, myristic acid, palmitic acid, stearic acid and isostearic acid.
2 higher fatty acids; 1,2-dihydroxystearic acid;
8 to 22 carbon atoms such as lauric acid amide, myristic acid amide, palmitic acid amide, and stearic acid amide
Higher fatty acid amides; liquid hydrocarbons, synthetic paraffins and other aliphatic hydrocarbons; glycerin, propylene glycol and other monoglycols; polyethylene glycol,
Polyglycols such as polypropylene glycol are mentioned, which are used alone or in combination of two or more.

The stretch film in the present invention is formed by a conventionally known production method, that is, a T-die method or an inflation method. The thickness of this stretch film is usually about 8 to 25 μm.

[0034]

EXAMPLES The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to the description of these examples.

(Examples 1 to 9 and Comparative Examples 10 to 20) 10 parts by weight of epoxidized soybean oil, 1 part by weight of Ca-Zn higher fatty acid salts and 100 parts by weight of polyvinyl chloride resin and Tables 1 and 2 were used. Predetermined amount (parts by weight) of the indicated plasticizer and antifogging agent
After adding and kneading with a Henschel mixer, a film was formed by a T-die method, a polyvinyl chloride film having a thickness of 15 μm and a width of 350 mm was wound up, and [low temperature strength] and [low temperature antifogging property] were evaluated by the following methods. .

[Low-temperature strength] A low-temperature drop test was carried out as a method for evaluating the strength against vibration and shock during distribution and storage in the freezing temperature range, and a packaging test was carried out as a method for evaluating the ability to protect products. ] Was evaluated. Low-temperature falling ball test In the freezing temperature range of -30 ° C, 30 g of iron balls were dropped vertically from a height of 50 cm to one stretched film, and the film was not cracked. Was evaluated as x. Packing test Shrimp tray No. 25 (Chuo Kagaku Co., Ltd. product name) is packed with 12 frozen shrimp, and after packing 10 packs with an automatic wrapping machine A-18X (Fujikikai Co., Ltd. product), -25 ° C.
The film was stored in a freezer at -30 ° C for one week, and the state of the film after storage was confirmed and evaluated. If the film that is in contact with frozen shrimp, which is the object to be packaged, is not cracked or torn and the object to be packaged can be protected, that is, if the strength at low temperature is excellent, the film is cracked or torn. Then, the case where the packaged item could not be protected was evaluated as x.

[Low-temperature anti-fog property] Shishamo 8F (trade name of Chuo Kagaku Co., Ltd.) is packed with 8 shishamo, and automatic packaging machine A-
After packing 10 packs by 18X (trade name, manufactured by Fujikikai Co., Ltd.), it is stored in a freezer at −25 to −30 ° C. for one week, and then put in a showcase at −2 ° C. to 5 ° C. for 1 week.
The low-temperature anti-fog property at the time point when the time passed was evaluated. If the water content of the packaged product is uniform without condensation on the film surface and the packaged product looks clear, that is, if the low-temperature anti-fog property is excellent, then the packaged product The case where the water film contained contained coagulation or the water film was not uniform and a part thereof became a lens shape was evaluated as x.

In Tables 1 and 2, plasticizer DINA represents diisononyl adipate and C _6,8,10 A represents C _6,8,10 adipate.

[0039]

[Table 1]

[0040]

[Table 2]

As is clear from the results shown in Tables 1 and 2, the plasticizer is added in an amount of 25 to 45 parts by weight and the antifogging agent is added in an amount of 2.0 to 100 parts by weight of the polyvinyl chloride resin.
It is in the range of 4.0 parts by weight, and the addition amount of the plasticizer of (1) is 40 to 40 with respect to the total addition amount of the plasticizers of (1) and (2).
The antifogging agent is in the range of 80% by weight, and the antifogging agent of 1.5-2.
It was found that a film excellent in both low temperature strength and low temperature anti-fogging property was obtained at a film thickness of 15 μm only when 5 parts by weight of 0.5 to 1.5 parts by weight of an antifogging agent was added.

[0042]

INDUSTRIAL APPLICABILITY The stretch film of the present invention can be used for packaging various articles, and further contains a specific amount of a specific plasticizer in a specific ratio and a specific amount of a specific antifogging agent. Especially excellent in low temperature strength and low temperature anti-fog property,
It is possible to provide a film suitable for packaging foods that are distributed, stored, or sold in a frozen state or a refrigerated state.

Claims (1)

[Claims] 1. A plasticizer of 25 to 45 parts by weight and an antifogging agent of 2.0 to 4. per 100 parts by weight of a polyvinyl chloride resin.
A polyvinyl chloride stretch film obtained by mixing 0 parts by weight, wherein the plasticizer is (1) an adipic ester plasticizer having an alkyl group having 9 or more carbon atoms, and (2) having 10 or less carbon atoms. A mixed adipate ester-based plasticizer obtained by reacting two or more kinds of aliphatic alcohols having an alkyl group with adipic acid, wherein the plasticizer (1) is added in the amount of (1) and (2). 40 to 80% by weight based on the total amount, and the antifogging agent comprises an antifogging agent selected from the group consisting of glycerin fatty acid ester and sorbitan fatty acid ester, and a polyoxyethylene alkyl ether. The addition amount is 1.5 to 2.5 parts by weight, and the addition amount is 0.5.
A polyvinyl chloride stretch film characterized in that it is in the range of 1.5 parts by weight.