JPH02115245A - Packaging polybutadiene film composition - Google Patents

Abstract

PURPOSE:To obtain the title composition which can give a film which can exhibit a freshness-retaining effect without detriment to its transparency, gloss, orientability, etc., when used for packaging perishable food by mixing a butadiene resin with zeolite and, optionally, an antifogging agent. CONSTITUTION:A packaging polybutadiene film composition is produced by mixing 100 pts.wt. butadiene resin (containing at least 60% syndiotactic 1,2- polybutadiene and having an average MW >=100000 and a crystallinity <=50%) with 2-20 pts.wt. zeolite and, optionally, 0.2-1 pt.wt. antifogging agent (e.g., sorbitan fatty acid ester). A film prepared from this composition can exhibit a freshness-retaining effect without detriment its to transparency, gloss, orientability, etc., when used for packaging perishable food.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention produces a film that exhibits a freshness preservation effect when packaging fresh foods without impairing transparency, gloss, stretchability, etc. The present invention relates to a polybutadiene film composition suitable for packaging.

[Conventional technology]

Conventionally, films made of polyethylene or vinyl chloride resin have been commonly used as packaging films for fresh foods, especially fruits and vegetables.However, when fruits and vegetables are packaged with these films, water droplets may adhere to the inside of the film.
Gases emitted from fruits and vegetables, such as ethylene and carbon dioxide, are trapped, and the presence of oxygen in packaging containers can cause fruits and vegetables to spoil and lose their freshness, reducing product value. It was impossible to preserve it for a long time.

[Problem that the invention seeks to solve]

For this reason, it is recommended to use polybutadiene film, which has excellent gas permeability, instead of films using polyethylene or vinyl chloride resin. It has been proposed in recent years.

However, when fruits and vegetables are simply packaged and stored using polybutadiene film, the disadvantages of water droplets adhering to the inner surface of the film and odor being trapped have not been improved at all.

In addition, in recent years, in the food service industry such as family restaurants and fast foods, cabbage,
The so-called power, made with vegetables such as lettuce, Chinese cabbage, and carrots,
Demand for primary processed products such as vegetables is increasing.

However, if cut vegetables are left exposed to the air, they will wilt and turn brown, especially at the cut surfaces, and if they are sealed and packaged in plastic with low gas permeability, they will suffer from so-called anaerobic respiration. Eventually, alcohol, which causes off-flavors, is likely to be generated, making it impossible to store cut vegetables for a long time, and thus making it difficult to transport cut vegetables over long distances.

(Means for Solving the Problems) Therefore, as a result of extensive studies in order to solve the above-mentioned drawbacks, the present inventors have developed a method of using zeolite, which has excellent water absorption and adsorption properties, for polybutadiene. They discovered that even when fruits and vegetables are packaged and stored using the film obtained by blending the ingredients, water droplets do not adhere to the inner surface of the packaging film and odor does not accumulate, and the present invention was completed.

In other words, the present invention provides a polybutadiene film for packaging, comprising 2 to 20 parts by weight of zeolite and, if necessary, 0.2 to 1 part by weight of an antifogging agent to 100 parts by weight of butadiene resin. It is a composition.

The polybutadiene used in the present invention contains 60% or more of syndiotastic-1,2-polybutadiene, has an average molecular weight of 100,000 or more, and has a crystallinity of 50% or less. In particular, it is preferable that the 1.2-bond is 90% or more and the degree of crystallinity is 15 to 35% because film formability is easy.

The zeolite may be either natural or synthetic. Natural products include fluorite and similar minerals, such as alkali, alkaline earth, and aluminum hydrated tectosilicate minerals. Synthetic products include zeolite I-A and zeolite. , zeolite X, mordenite, etc.

Incidentally, the average particle diameter of the zeolite is preferably 20 μm or less. If the average particle diameter is too large, fins are likely to occur in the film, which reduces the commercial value of the film, which is undesirable. The amount added is 2 to 20 parts by weight, preferably 3 parts by weight, per 100 parts by weight of Butashev resin.
~15 parts by weight.

If the amount of zeolite added is less than 2 parts by weight, the odor (
For example, the adsorption effect and permeation effect on carbon dioxide, ethylene, etc.) are no longer exhibited. On the other hand, if it exceeds 20 parts by weight, the flexibility, stretchability, and tensile strength of the film will be extremely reduced, and the water absorption and adsorption properties will not improve much, which is not preferable.

Furthermore, an antifogging agent may be added to the composition of the present invention, if necessary. For example, when a film containing a fogging agent is used for packaging vegetables and fruits containing a large amount of water, the effects of the present invention will become more apparent. The antifogging agent used in this case is preferably one that is used in -C for packaging films. Examples include polyglycerin fatty acid ester, sorbicun fatty acid ester, and glycerin fatty acid ester. The amount of IJD added is preferably 0.2 to 1 part by weight.

The method for producing the composition of the present invention involves blending a specific amount of Pukugen resin and zeolite with an antifogging agent if necessary.
It is obtained by melt-kneading in a conventional manner using a panbari mixer, roll or extruder.

Note that the zeolite is preferably pre-dried to remove adsorbed moisture before being blended with the butadiene resin.

Further, if necessary, an antioxidant, an ultraviolet absorber, an antistatic agent, etc. may be mixed as appropriate.

The film can be manufactured using ordinary forming methods such as inflation processing and T-die processing, and the thickness of the film is as follows:
The effect of the present invention is best exhibited when the thickness is about 10 to 60μ.

Examples and comparative examples of the present invention will be described below.

Example 1 Butadiene resin (Nippon Gosei product: JSR820) 1
00 parts by weight, sodium salt type A synthetic zeolite with a particle size of 2μ (Product 2 type 40 manufactured by Sinanen New Ceraminok Co., Ltd.)
After mixing 0) 5 parts by weight in a V blender, this mixture was kneaded and extruded in an extruder to obtain a pelletized polybutadiene film composition for packaging of the present invention.

The pellets of the composition obtained above were put into a cylinder with an inner diameter of 40 mm.
A film with a thickness of 40 μm was obtained by a melt extrusion air-cooled inflation method using a Ryu, L/D = 28 extruder.

The air-cooled inflation molding conditions were as follows: the temperature of the annular die was 140'C, the tensile speed was 18 m/min, and the blow-up ratio was 5.

Using the film obtained in this example, tomatoes were packaged, packed in cardboard boxes, and stored at room temperature in August.

The packaged tomatoes were visually judged (immediately before harvesting was given a score of 5), and the results are shown in Table 1.

Comparative Example 1 Example 1 was the same as Example 1 except that the amount of zeolite used was 25 parts by weight.

Table 1 From the results in Table 1, it was possible to extend the freshness of the product for about 5 to 6 days instead of the conventional 2 to 3 days.

Example 2 To 100 parts by weight of the butadiene resin used in Example 1, 5 parts by weight of zeolite with a particle size of 3.87μ (product manufactured by Mizusawa Chemical Co., Ltd.: 13X type zeolite) and sorbitan lauric acid ester as an antifogging agent were added as the main components. A pale yellow oily substance with a hydroxyl value of 330 (product manufactured by Riken Bikmin Oil Co., Ltd.: Rikemar L-
250) Add 0.5 parts by weight.

For the subsequent operations, a film with a thickness of 40 μm, which is the same as in Example 1, is obtained.

Using the film obtained in this example, dried cabbage cut into 2 mm width was packaged and stored in an environment of 5°C.

The packaged cabbage was visually evaluated in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Example 2 Example 2 was the same as Example 2 except that the amount of zeolite used was 1 part by weight.

Table 2 The results shown in Table 2 show that the freshness of the food, which was conventionally maintained for 2 to 3 days, could be extended to about 5 to 6 days.

Example 3 100 parts by weight of the butadiene resin used in Example 1 was blended with 4 parts by weight of calcium salt type A synthetic zeolite (product 2 type 500 manufactured by Sinanen New Ceramic Co., Ltd.) with a particle size of 3 μm, and the resin was mixed with 100 parts by weight of the butadiene resin used in Example 1. Do the same operation.

Lettuce was packaged using the 40 μm thick film obtained in this example and stored in a 15° C. environment.

The packaged lettuce was visually judged in the same manner as in Example 1, and the results are shown in Table 3.

Comparative Example 3 Example 3 was the same as Example 3 except that the amount of zeolite used was 1 part by weight.

When fruits and vegetables are packaged as shown in Table 3, no change occurs in the fruits and vegetables even after storage for about - weeks.

Therefore, when transporting fruits and vegetables from production areas to consumption areas, or delivering cut vegetables, the vegetables can be safely transported to their destinations without worrying about browning or damage during the process.

From the results shown in Table 3, it was possible to extend the freshness of the food for about 5 to 6 days from the conventional two-day period.

〔Effect of the invention〕

If fruits and vegetables are left unwrapped for 2 to 3 days, or even if they are wrapped in conventionally used polyethylene film or PVC film, the fruits and vegetables may turn brown or become damaged within 3 to 4 days. It has lost significant value.

However, the film patent applicant Tokyo Ink Co., Ltd. manufactured using the packaging polybutadiene film composition of this invention

Claims (1)

[Claims] For 100 parts by weight of butadiene resin, 2 to 20 parts by weight of zeolite and, if necessary, 0.2 parts by weight of antifogging agent.
A packaging polybutadiene film composition comprising ~1 part by weight.