JPS5839856B2 - food packaging materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a packaging material made of polyvinyl chloride, and more particularly to a packaging material made of plasticized polyvinyl chloride that is suitable for food packaging and is free from toxicity concerns.

Traditionally, many packaging materials have been made from plastic materials.

Among them, polyvinyl chloride is inexpensive, and depending on the amount of plasticizer mixed in, it can be used for a wide range of purposes, from soft to hard, and is transparent and easy to process. , has been widely used.

However, it has recently been discovered that phthalate esters, including dioctyl phthalate, which have traditionally been used as non-toxic plasticizers for polyvinyl chloride, can cause various serious diseases if they enter the human body. It is suggested that this will happen.

[For example, S ingii A, R. et, al,
J, Pharm, Sci, 61 (1), 51 (197
2): 0hta H,, J, J apaneseP
athology, 62 119 (1973); Dan
iel J, W, et al, , Poxic
251 (1974)) When a polyvinyl chloride molded product plasticized with a phthalate ester comes into contact with an oil-containing food, the phthalate ester
It is extracted by fats and oils in food and migrates into food.

For example, it is known that phthalate esters migrate into food from polyvinyl chloride food packaging plasticized with phthalate esters and accumulate in human tissues when the stored food is eaten.

In the tests conducted by the present inventors, it was found that various plasticizers can be extracted from plasticized polyvinyl chloride by various foods, especially foods containing oil and fat, even if the amount of plasticizers is very small. ing.

It is an object of the present invention to provide a plasticized polyvinyl chloride packaging material that does not contain toxic plasticizers extracted by oil-containing foods.

According to the present invention, a thermoplastic polyester type polyurethane having a softening point of about 70°C, which does not cause spots other than the origin in thin layer chromatography, is made of 50 ioo parts by weight of polyurethane and 100 parts by weight of polyvinyl chloride as plasticizers. A food packaging material made of plasticized polyvinyl chloride is provided.

The packaging material of the present invention is disclosed in U.S. Pat.
No. 0802, it is disclosed as a medical device material.

The present invention seeks to extend the use of the material to food packaging.

The thermoplastic polyester polyurethane used has a linear structure and is composed of a polyester component and an alkylene or polyoxyalkylene diisocyanate component.

The polyester component is derived from an aliphatic diol having at least 6 carbon atoms and an aliphatic dicarboxylic acid having at least 6 carbon atoms and has a hydroxyl number of 50-60.

The softening point of this polyurethane is about 70°C.

It has been found that such polyester type polyurethane, unlike polyether type polyurethane, is well compatible with polyvinyl chloride and plasticizes it.

The blending amount is 5 parts by weight per 100 parts by weight of polyvinyl chloride.
O-100 parts by weight give molded products for various uses ranging from soft to near-hard.

For example, 60-90 parts by weight of polyester polyurethane is mixed in soft sheets and bags, and 50-70 parts by weight in hard sheets, bottles and boxes.

The polyurethane used has a softening point of about 68 DEG to about 72 DEG C. and must not contain any impurities that would cause any spots other than the origin in the thin layer chromatography test.

Polyvinyl chloride materials plasticized with polyurethanes containing such impurities contain impurities that migrate into food products, which can also be readily determined by means of gas chromatography.

In the present invention, thin layer chromatography for selecting polyurethanes was carried out by Y. LlMarcel, et al.
.

Al, report (Lancet, 1 35 (1970))
shall be conducted in accordance with the

That is, the length of the polyurethane molded product is 1.5c1rL, and the width is 0.
．． 5 crn, 5 grams of 0.40.5 mm thick strips were placed in a flask, 100 ml of chloroform was added, the flask was sealed, and the flask was left to sweat for 3 hours at room temperature. After solidifying and drying, 101 rL of methanol was added to prepare a test solution, and 10 μl of this was charged onto 0.251 m thick silica gel to perform thin layer chromatography (developing solvent: n-hexane/ethyl acetate (9:1). ).

Development temperature: room temperature, development distance: 10CrIL, ascending method),
The presence or absence of spots appearing on the thin layer is detected using the iodine vapor method.

Gas chromatography for quantifying phthalate esters such as dioctyl phthalate (DOP) and diptyl phthalate (DBP) migrated into foods is performed as follows.

After the test food is homogenized if necessary, it is extracted with n-hexane and diethyl ether, respectively.

Mixing the n-hexane extract with acetonitrile,
Shift the plasticizer towards acetonitrile.

The acetonitrile solution and the diethyl ether solution obtained above were each added to Florisle.
Charge the column.

Each column was treated with n-hexane diethyl ether (97:
After washing with the mixed solvent of step 3), it is eluted with a mixed solvent of n-hexane/diethyl ether (30:20).

The respective eluates are mixed, vacuum dried at 50° C. or lower, and the dried product is dissolved in a small amount of tetrahydrofuran.

The solution is subjected to heated gas chromatography under the following conditions.

(Conditions for phthalate ester) Column: 3% 5E-30, Chromosorb W-
AW humidity temperature indicator - 280°C, column 230'C
Detector: 280°C Detector: FID Particularly when used in food tubes or bags, if the amount of compounded polyurethane exceeds 100 parts by weight per 100 parts by weight of polyvinyl chloride, the amount of permeation of the content liquid will decrease. I don't like it because it increases.

Furthermore, if the amount is less than 50 parts by weight, plasticization is insufficient.

The plasticized polyvinyl chloride may further be formulated with stabilizers such as stearates.

The packaging material of the present invention is produced by heating and kneading the blended polyvinyl chloride to form pellets, which are then processed by conventional processing methods such as extruders, calendars, inflation rollers, etc. to produce films, sheets, tubes, bottles, etc. Obtained by forming into a box or the like.

The molded articles (Medidex®) are transparent and can withstand sterilization with ethylene gas or high-pressure steam and pass the test according to the method described above.

The transpiration loss of aqueous solution through the bag wall does not exceed the limit of 4.0% specified in the Ministry of Health and Welfare notification.

The physical properties of the sheet-like material of the present invention containing a plasticizer of 70PHH were determined by comparing the physical properties of polyvinyl chloride (PVC) plasticized with dioctyl heptalate (
Table 1-6 shows the physical properties of PVC-DOP.

One of each sample contained ethylene oxide carbon dioxide (1
0:90) mixed gas, 55-65℃, relative humidity 50-
Sterilize for 4 hours at 60%, and
It was sterilized in an autoclave at 120°C for 20 minutes.

As is clear from the table, Medidex ■ exhibits superior mechanical properties in the low temperature range compared to conventional polyvinyl chloride plasticized with dioctyl phthalate.

Similar results were obtained from the following tests on the strength of the sheets: Bags containing water, consisting of each sample sheet, were subjected to a destructive test by dropping them onto the floor at low temperatures.

The results are shown in Table 7. Food products packaged with the packaging material of the invention may be of any composition and may be in solid, semi-solid or liquid state.

Among them, foods consisting of or containing fats and oils that are most compatible with common plasticizers can be safely packaged and stored at low temperatures for long periods of time with the packaging material of the invention.

The material of the present invention is resistant to sterilization, exhibits excellent physical properties at low temperatures, and does not elute phthalate esters, so it is playing an important role in the medical field for infants and patients. It can be preferably used for food packaging.

There are many patient and infant foods that consist of key nutrients that are in semi-solid form.

The following is a typical example of such a semi-solid food for patients.

The present invention will be explained in more detail with reference to the following examples.
The present invention is not limited to these.

Examples and Comparative Examples Materials and Methods: Materials: Medide long bags: made of polyvinyl chloride (average degree of polymerization 1100, produced by suspension polymerization) plasticized with 70 PHR of the newly synthesized polyurethane in the present invention. Molded from 0.42-0.40mm sheet.

Commercially available polyvinyl chloride blood bag: Thickness: 20.41-0.45 plate Food: Pack 100 ml of each of the foods listed in Table 8 and the labeled food into the above two bags with a capacity of 150 ml and leave at 27°C for 30 days. Method: After each food was taken out and extracted by the method described above, the tetrahydrofuran extract was analyzed by gas chromatography for phthalate esters.

result: Shown in Table 9.

Comparative Experimental Example An experiment was conducted to prove that the composition of the present invention does not emit any leachables in foods containing fats and oils.

Plastic molded using commercially available polyether type polyurethane and PVC (P-1), plastic molded using PVC and commercially available polyester type polyurethane in which aliphatic diol and aliphatic dicarboxylic acid each have 6 or less carbon atoms , PvC with a plastic composition defined in the present invention and a phthalate ester as a plasticizer.
Using (P.3) as a test material, it was immersed in edible oil, and the eluate was analyzed by thin layer chromatography to examine the presence or absence of components other than fat.

Extraction conditions and preparation of test solution: Cut the sample into 5 x 1 mm pieces, add 1 liter of soybean oil per 12 samples, and
Extraction was carried out under two temperature conditions: C/1 hour and 37° C./7 days.

This extract was poured into a stainless steel wire mesh.
) and used as a test solution.

Analysis conditions: Transfer 10μl of test solution to Silicagel G
Charge it into a thin layer (0.08mm) and use it as a developing solution (1)
The reaction mixture was developed using n-hexane:benzene (1:1) and (2) petroleum ether:ether:acetic acid (82:18:1) at room temperature for about 10 CrrL, and after the solvent was evaporated, detection was performed using iodine vapor.

Test results: As a result of testing using the above method, the extraction conditions were 1.
The test results were the same in both cases of 21°C/hour and 37°C/7 days.

The chromatogram was as shown in FIG.

The figure shows the case of 121°C/1 hour.

Because soybean oil is used as the resin extraction solvent, many spots of fatty acids derived from soybean oil can be seen.

In the case of any developing solvent, the largest spot is neutral fat.

In the case of the composition selected in the present invention, spots different from spots derived from soybean oil are not observed in any developing solvent, but spots other than those derived from soybean oil are observed in other samples.

When testing with a developing solvent of n-hexane:benzene (1:1), a spot of RfO, 22 of unknown origin on P.1, is detected using a developing solvent of petroleum ether:ether:acetic acid (82:18:1). RfO for both P・1 and P・20 types
, 34 spots of unknown origin have been recognized.

Furthermore, in P.3, a large spot derived from di-2-ethylhexyl phthalate and a spot of RfO,29 of unknown origin were observed near RfO,4.

From the above, the composition selected in the present invention did not show any spots of unknown origin, and therefore it was considered that there was no elution into soybean oil.

[Brief explanation of drawings]

FIG. 1 shows comparative data of the packaging material of the present invention and the known packaging material by thin layer chromatography using soybean oil extraction.

Claims (1)

[Claims] 1 A linear polyester component with a hydroxyl value of 50-60 derived from an aliphatic diol having at least 6 carbon atoms and an aliphatic dicarboxylic acid having at least 6 carbon atoms and having a softening point of about 70°C, and an alkylene diincyanate. or 60-90 parts by weight of polyurethane and 100 parts by weight of polyvinyl chloride, which are thermoplastic polyester-type polyurethanes that are free from polyoxyalkylene diisocyanate fractions and are used as plasticizers that do not show spots other than the origin in thin layer chromatography. A packaging material for food containing oil and fat, characterized in that it is made of plasticized polyvinyl chloride.