JPH0131386B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a deodorizing resin composition and a deodorizing packaging material, and more specifically, to providing a deodorizing packaging material suitable for packaging various odorous articles. purpose.

(Prior Art) Conventionally, deodorizing agents have been widely used to treat various sources of bad odors, and non-porous plastic films, aluminum foils, metal Containers, glass containers, etc. are used.

(Problems to be Solved by the Invention) Conventional packaging using non-breathable packaging materials as described above can prevent the odor of the contents from evaporating outside, but when the containers are opened, It is inconvenient to handle because the odor that is pervading the inside evaporates outside all at once.

As a result of intensive research to solve the above-mentioned drawbacks of the prior art, the inventor of the present invention has developed a plastic film.
When manufacturing packaging materials such as plastic sheets or plastic containers, when a specific substance is encapsulated in the thermoplastic resin used, the resulting packaging material has excellent deodorizing properties, and conventional techniques such as those described above are used. The present invention was completed based on the finding that the above drawbacks can be solved.

(Means for Solving the Problems) That is, the present invention provides a deodorizing resin composition comprising 99.9 to 80 parts by weight of a thermoplastic resin and 0.1 to 20 parts by weight of an aliphatic polycarboxylic acid, and a deodorizing packaging material formed from the composition. It is.

Next, to explain the present invention in more detail, the thermoplastic resin used in the present invention refers to polyolefins such as polyethylene and polypropylene, which are conventionally used for molding various packaging materials, such as plastic films, sheets, and plastic containers. resin,
It is a synthetic or modified thermoplastic resin such as polyvinyl chloride, polystyrene, polyamide, cellulose acetate, etc., and all of these thermoplastic resins are easily available on the market.

The aliphatic polycarboxylic acids used in the present invention and which mainly characterize the present invention include, for example, oxalic acid,
malonic acid, succinic acid, glutaric acid, adipic acid,
Di- or tricarboxylic acids such as pimelic acid, fumaric acid, maleic acid, methylmaleic acid, methylfumaric acid, itaconic acid, citraconic acid, mesaconic acid, acetylenic acid, malic acid, methylmalic acid, citric acid, isocitric acid, tartaric acid, etc. Particularly preferred in the present invention are tricarboxylic acids, especially citric acid.

Any of the above aliphatic polycarboxylic acids can be used in the present invention, and the amount thereof used is preferably 0.1 to 20% by weight in the total weight of the thermoplastic composition. If the amount used is less than 0.1% by weight, the deodorizing effect will be insufficient, and if the amount exceeds 20% by weight, it will be uneconomical.

According to detailed research by the present inventors, among the aliphatic polycarboxylic acids mentioned above, tricarboxylic acids, such as citric acid, have a particularly remarkable deodorizing effect, and citric acid has also been used as a food additive. Even if the packaged item is food,
This is advantageous because it does not contaminate these foods. Furthermore, unexpectedly, when the packaging material of the present invention using such citric acid is used to package foods that are easily oxidized, oxidation is prevented, such as when packaging fatty foods, fruits, vegetables, etc. As a result, they discovered that they could prevent their rancidity and decomposition of vitamins.

The deodorizing resin composition of the present invention has the above-mentioned two components as essential components, and includes other conventionally known additives for resins, such as colorants, fillers, extender pigments, plasticizers,
Stabilizers, ultraviolet absorbers, etc. can be added as desired.

The deodorizing resin composition of the present invention can be obtained by simply mixing the above-mentioned components, or it can be obtained by melt-kneading the mixture and granulating it into pellets or the like. Furthermore, it may be in the form of a masterbatch containing a high concentration (for example, 10 to 20% by weight) of aliphatic polycarboxylic acid for later use by diluting with additive-free resin.

The resin composition of the present invention as described above is useful for producing the deodorizing packaging material of the present invention.

The deodorizing packaging material of the present invention is a packaging material made of the above-mentioned resin composition in various shapes, such as a packaging material made of a plastic film or sheet, or a container of any shape formed by molding the resin composition by various methods. .

Forming of such films, sheets, containers, etc. is carried out using conventionally known inflation devices, presses,
The packaging material of the present invention can be easily obtained by using a calendar, an extrusion molding machine, a blow molding machine, an injection molding machine, a vacuum molding machine, etc., using various conventionally known conditions as they are.

(Function/Effects) In the packaging material of the present invention as described above, free carboxyl groups of the aliphatic polycarboxylic acid used are exposed on the surface and gradually bleed to the surface. It has the property of adsorbing and retaining amine-based, ammonia-based, and other basic odor components. Therefore, if the item to be packaged is used to package items with strong odors, such as fish, fish products, various pickles, and other various foods, the packaging material itself will absorb the odor emitted from the items, so these packaging items should not be used. Even when opened, strong odors do not spread to the surrounding area. For the same reason, it is also effective for packaging not only food but also various household garbage, factory waste, etc.

In particular, those using citric acid as the aliphatic polycarboxylic acid are effective for food packaging, and not only produce the effects described above, but are also effective in preventing packaged foods from becoming rancid and destroying vitamins. Therefore, it is also suitable for packaging odorless foods.

Next, the present invention will be explained in more detail with reference to Examples. In the text, parts or percentages are based on weight.

Example 1 1 part of citric acid was blended with 99 parts of low-density polyethylene, mixed with a mixer, and a 40 m/m extruder (L/D
=28, CR=3.1.Screw with dullage, cylinder temperature 130℃, screw rotation speed 70rpm)
The mixture was kneaded to obtain a pellet-like deodorizing resin composition of the present invention.

Next, the above resin composition was put into an inflation device (30 m/m extruder, inner diameter 50 m/m inflation die, cylinder temperature 140%, screw rotation speed 60 rpm) to obtain a polyethylene film with a wall thickness of about 50 μm. .

Cut the above film into a size of 50mm x 210mm,
These two films were hung like an umbrella in a 300 ml Erlenmeyer flask, and the opening was sealed with paraffin film. This flask contains 42ppm as a source of bad odor.
100 ml of ammonia water was placed in the flask, and after a certain period of time, the ammonia (ppm) in the atmosphere inside the flask was measured using a Kitagawa gas detection tube.The results were as follows.

1 day, 2 days, 9 days, blank 15 15 15 Invention product 14 9 9 Note. The blank is a polyethylene film of the same thickness and size formed from the same polyethylene without citric acid added.

In addition, bags were made from each of the above-mentioned blank and the film of the present invention, thawed small fish were placed in the bags, and the bag was left to stand.When the bag was opened after 3 days, it was found that the bag was made from the film of the present invention. While the odor inside the bag was slight, a strong odor was diffused in the case of the blank.

Examples 2 to 4 Plastic films of the present invention were obtained in the same manner as in Example 1 except for using the following components.
When the performance was measured in the same manner as above, the results were as follows.

Example 2 High density polyethylene 95 parts Citric acid 5 parts 1 day later 3 days later 9 days later blank 16 23 15 Invention product 10 7 4 Example 3 Polypropylene 97 parts Citric acid 3 parts 1 day later 2 days later 9 days later blank 15 24 13 Invention Product 12 13 5 Example 4 Polystyrene 98 parts Citric acid 2 parts 1 day, 2 days, 9 days later Blank 15 15 15 Invention product 10 7 5 Example 5 20 parts of citric acid was blended with 80 parts of high-density polyethylene, and the following Examples Same as 1, citric acid concentration 20
% of the resin composition of the present invention was obtained.

This composition was mixed with additive-free high-density polyethylene for 20 minutes.
Dilute it twice and use it in a blow molding machine (45 m/m screw, screw rotation speed 30 rpm, cylinder temperature).
200℃), with a wall thickness of 1m/m and a diameter of 60m/m.
A bottle-shaped molded product with a height of 170 m/m was obtained. Put some rotten meat in this container and seal it.
When opened after being left for 3 days, the odor was significantly weaker than in the case of the same container without citric acid.

Example 6 In place of citric acid in Example 5, tartaric acid, malic acid, and maleic acid were similarly used.
It also had an excellent deodorizing effect.

Claims (1)

[Scope of Claims] 1. A deodorizing resin composition comprising 99.9 to 80 parts by weight of a thermoplastic resin and 0.1 to 20 parts by weight of an aliphatic polycarboxylic acid. 2. A deodorizing packaging material formed by molding a resin composition comprising 99.9 to 80 parts by weight of a thermoplastic resin and 0.1 to 20 parts by weight of fatty acid polycarboxylic acid.