JPS5893746A - Vinyl chloride resin composition and streched film for food packaging - Google Patents

Abstract

PURPOSE:To provide a vinyl chloride resin compsn. which gives a film having excellent packaging adaptability and unwindability, by blending a specified dialkyl ester and dibutyl sebacate or acetyl tributyl citrate with a vinyl chloride resin. CONSTITUTION:Not less than 21pts.wt. at least one dialkyl ester selected from diisononyl adipate, a di-n-C6, C8 or C10 alkyl adipate, a C7, C9 or C10 straight- chain and/or branched chain dialkyl adipate and di(2-ethylhexyl) azelate, and 2-12pts.wt. dibutyl sebacate and/or acetyl tributyl citrate are blended with a vinyl chloride resin. Examples of said vinyl chloride resins are vinyl chloride homopolymer, vinyl polymers composed mainly of vinyl chloride and copolymers of vinyl chloride with a copolymerizable monomer such as vinyl acetate or ethylene.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vinyl chloride resin composition for food packaging and a stretch film for food packaging with excellent rollability and peelability formed from the composition.

PVC stretch film has excellent transparency,
Due to its flexibility, anti-fog properties, food preservation properties, and packaging suitability, it has recently been used in large quantities as a film for packaging foods such as supermarkets, meat, fresh fish, fruits and vegetables, and delicatessen dishes.

As a primary plasticizer used to impart flexibility and transparency to such food packaging vinyl chloride films, DOA (di-2-ethylhexyl adipate, hereinafter abbreviated as DOA) has conventionally been used. ) are by far the most used.

This is because DOA is a plasticizer with excellent cold resistance and flexibility, and was also considered to be a non-toxic plasticizer suitable for use in food packaging materials.

However, recently, the US National Cancer Institute (MCI)
) pointed out that DOA is suspected of being carcinogenic, and the Food and Drug Administration of the United States (hereinafter abbreviated as FDA) also
Consideration has begun toward regulating the use of OA in the food industry.

The FDA is a government agency with worldwide authority in ensuring the effectiveness and safety of food additives, pharmaceuticals, etc., and most of the regulations in this field in Japan are based on FDA regulations! Considering that this is the case, the use of such suspected DOA as a plasticizer for food packaging films should be avoided if possible, regardless of whether or not regulations are actually implemented. .

From this point of view, the present inventors have investigated whether there are any plasticizers that can be used in place of DOA as a plasticizer for vinyl chloride Streno'Typhirum among the many plasticizers whose safety is guaranteed and approved by the FDA. As a result of considering whether or not to use the material, we succeeded in selecting several types of plasticizers that were almost satisfactory in terms of flexibility, transparency, antifogging properties, etc.

However, when food is actually packaged with a stretch film containing such a plasticizer using a packaging machine (handler bag), (i) in some cases, the film blocks and cannot be unrolled from the roll; (11) or Even if it were possible to unroll it, there were many problems such as not being able to package it tightly or the adhesiveness between the films being low and peeling of the film over time. It has become clear that the packaging film containing

As a result of further investigation, the present inventors found that the above-mentioned packaging suitability can be quantitatively understood by whether or not the "rolling peel stress" defined below falls within a specific range. . For practical use, it has been found that by setting the value of the rolling peel stress J to 400 to 700f, a film with excellent packaging suitability can be obtained.

In fact, the conventional stretch film containing DOA plasticizer satisfies the conditions of lava, but when other plasticizers are used, the film inevitably falls outside the above range.

Based on this knowledge, the present inventors finally created a film with excellent packaging suitability and a peeling stress value within the above range by blending a specific amount of a specific plasticizer in a specific combination. They found that it can be obtained and completed the present invention.

That is, the present invention provides: (1) a vinyl chloride resin composition for food packaging, in which, based on 100 parts by weight of the above-mentioned vinyl chloride resin; selected from the group consisting of di-n-alkyl adipates with kerkyl groups, dialkyl adipates with straight-chain and/or side-chain alkyl groups of 7 or 9 carbon atoms, and di(2-ethylhexyl) azelate. A vinyl chloride resin composition for food packaging with excellent peeling properties, comprising: 21 parts by weight or more of at least one type of dialkyl ester; thing.

and (2) a vinyl chloride film for food packaging, which is mainly composed of vinyl chloride resin, in which diisononyl adipate, a moro-alkyl adipate having a linear alkyl group having 6.8 or 10 carbon atoms, dialkyl adipates with straight-chain and/or side-chain alkyl groups having 7 or 9 carbon atoms;
and at least one dialkyl ester selected from the group consisting of di(2-ethylhexyl) azelate and dibutyl sepacate and/or acetyl tributyl citrate. , and the winding peeling stress is 400~
700g vinyl chloride stretch film for food packaging.

I will provide a.

The present invention will be explained in detail below.

The vinyl chloride resin used in the present invention is a vinyl chloride homopolymer or a vinyl polymer mainly composed of vinyl chloride, and includes monomers copolymerizable with vinyl chloride, such as vinyl acetate, vinylitin chloride, diethyl maleate, and ethylene. , copolymers with propylene and the like. These vinyl chloride resins may be any resin obtained by conventionally known polymerization methods such as emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization, and the like.

In the present invention, two types of plasticizers defined below are used in combination as the plasticizer blended into the vinyl chloride polymer. (1) diisononyl adipates, moro-alkyl adipates having straight chain alkyl groups having 6.8 or 10 carbon atoms, straight chain and/or straight chain having 7 or 9 carbon atoms;
or (ii) a combination of dialkyl adipate having an alkyl group in the side chain, and at least one dialkyl ester selected from the di(2-ethylhexyl)'7 gelate group) butyl sebacate and/or acetyl tributyl citrate; do.

If a plasticizer belonging to the first group (diisononyl adipate, etc.) or a plasticizer belonging to the second group (dibutyl sebacate, etc.) is not used in combination,
If each of these is used alone, a resin composition with satisfactory peeling characteristics cannot be obtained.

In the present invention, when using the plasticizers selected in this way, diisononyl adipate, etc. belonging to the first group is added at 21 parts by weight per 100 parts by weight of vinyl chloride resin.
At least 2 parts by weight, and dibutyl sepacate, etc. belonging to the second group are added and blended in a proportion of 2 to 12 parts by weight. The added amount of plasticizer belonging to the first group is 2
If the amount is less than 1 part by weight, the value of the roll peeling stress of the obtained film becomes too large and exceeds the upper limit, making it impossible to unroll the film from the roll. In addition, in the case of films belonging to the second group, the value of the peeling stress of the film becomes too small and falls below the lower limit value, making it impossible to perform tight packaging at all. On the other hand, if it exceeds 12 parts by weight, the value of the winding peel stress becomes too large and exceeds the upper limit, and a film with satisfactory winding peeling characteristics cannot be obtained.

All of the plasticizers used in the present invention are commercially available and can be used as they are for the purpose of the present invention without any particular purification.

In addition, in the present invention, in addition to the plasticizer specified above (so-called primary plasticizer), a secondary plasticizer and other general additives may be contained as necessary. For example, it is optional to include epoxidized soybean oil, epoxidized linseed oil, antioxidants, ultraviolet absorbers, antistatic agents, lubricants, pigments, surfactants, and the like.

The vinyl chloride resin composition of the present invention is obtained by adding a specific amount of the above-mentioned specific plasticizer to a vinyl chloride resin, and adding other additives as necessary, and uniformly mixing them by a conventionally known method. It will be done.

Note that this resin composition can be prepared using known film forming means such as T-
10μ~30μ by die method or inflation method
It is formed into a film with a certain thickness.

Next, the winding peel stress, which is the most important factor defining the present invention, will be explained.

Roll peeling stress refers to the stress when a film wound into a roll is peeled from the roll, and is measured using a universal testing machine (or a device similar to Takeko) as follows.

(1) Measuring device The ones shown in Figures 1-6-4 are used.

3 (a cylindrical rod with bearing rolls 5 at both ends and two discs 6 slightly smaller than the inner diameter of the paper tube attached to the center), the scroll support 7 shown in Fig. 3, and the scroll support 7 shown in Fig. 4, respectively. As a universal testing machine, for example, Autograph manufactured by Takafusa Seisakusho and Tensilon manufactured by Toyo Baldwin are used.

(2) Measurement method■ Attach the scroll support stand 7 to the crosshead 11 of the universal testing machine 9.

■ Pass the shaft 3 through the scroll 15 and place it on the scroll support stand 7.・ ■ To wrap the film 13 around the film support plate 1 several times, secure the film support plate to the upper chuck 17 of the universal testing machine.

■ Start the universal testing machine and move the crosshead at a constant speed (
For example, 5 o o ”/f+) and any distance (for example, 3
00 Dragon) Bottom! let

■ Calculate the average value from the recording paper.
This is calculated as the winding peeling stress.

■ The test room shall be in the standard conditions specified in JIS-Z-8703 (temperature: 20±2°C, relative humidity: 65±5°C).

The stretch film for food packaging according to the present invention has a peeling stress value in the range of 400 to 700 f as measured by sniffing.

(i) If this value is less than 400f, the packaging machine (・
・Even if you try to wrap food using a plastic wrapper, the film will roll out without any response, resulting in unnecessary use of film, wrinkles in the film, making it impossible to wrap it tightly, and the adhesiveness of the films. is low;
(11) On the other hand, if this value exceeds 70of, the film may become blocked and cannot be unrolled from the roll (a roll of film wound around a paper tube). , and are torn, making them impractical as food packaging films.

Hereinafter, embodiments of the present invention will be explained using Examples, but these are merely illustrative and the technical scope of the present invention (
Article 70 of the Patent Act) shall not be construed to be interpreted in a limited manner based on these.

(Example) Using a Henschel mixer, the primary plasticizer listed in Table 1 (units are PH, R, that is, the number of parts by weight based on 100 parts by weight of polyvinyl chloride resin, the same applies hereinafter) Polyvinyl chloride resin (Mitsui Toatsu Chemical Vinicron 4000M) and the following additives: epoxidized soybean oil (Adeka Argus), 15PHR Qa-7,n stabilizer (Katsuta Kako) 1,0PHR diglycerin Heat and mix with 1.8 PHR' of surfactant (manufactured by Marubishi Yuka Co., Ltd.), use an extruder to mix the screws, melt-extrude from a T-die at about 210°C, and use a winding machine to form a sheet using a conventional method to a thickness of approx. A film of 18 μm and a width of 300 kat was made and wound into a roll. Table 1 shows the results of measuring the peeling stress of the obtained roll using the method described above.

(Comparative Example) Table 1 shows the results of the same test as in Example except that the blended weight part of the primary plasticizer was changed.

It is a schematic diagram.

In the figure, l...Film support plate, 3...Shaft, 7...Scroll I3...Film, 17
... Upper chuck, 23 ... Load cell, 25 ... Amplifier, 27 ... Recorder patent applicant Mitsui Toatsu Chemical Co., Ltd.

Claims (2)

[Claims] (1) A vinyl chloride resin composition for food packaging, in which, based on 100 parts by weight of the vinyl chloride resin described in At least one dialkyl ester selected from the group consisting of n-alkyl adipate, dialkyl adipate having a straight chain and/or side chain alkyl group having 7 or 9 carbon atoms, and di(2-ethylhexyl) azelate. 2 to 12 parts by weight of dibutyl sepacate and/or acetyl tributyl citrate. A vinyl chloride resin composition for food packaging with excellent roll release properties. (2) A vinyl chloride film for food packaging, which is mainly made of vinyl chloride resin, in which diisononyl adipate, di-n-alkyl adipate having a linear alkyl group having 6.8 or 10 carbon atoms, and carbon The number of atoms is 7'-! Dialkyl adipate having 9 linear and/or side chain alkyl groups,
and λ2-ethylhexyl) azelate, and dibutyl sebacate and/or acetyl tributyl citrate. Rolling peel stress 400~70
01 vinyl chloride stretch film for food packaging.