JPS5823845A - Vinylidene chloride copolymer composition - Google Patents

Abstract

PURPOSE:A composition useful as packaging film for foods, having improved film-forming properties by inflation method, transparency, adhesivity, etc., obtained by blending a vinylidene chloride copolymer with an epoxidized vegetable oil and a glycerol ester containing specific acryl groups. CONSTITUTION:100pts.wt. vinylidene chloride is under heating blended with 0.3- 3pts.wt. epoxidized vegetable oil (preferably linseed oil, etc.) as a stabilizer and 1-15pts.wt. glyceride obtained by blending a glycerol ester containing an acyl group obtained from 2-6C lower fatty acid and a glycerol ester containing an acyl group obtained from 8-22C higher fatty acid, preferably glyceride (e.g., diacetylcapryl glyceride, etc.) having a reduction in weight under heating at 190 deg.C for 30min of <=40wt% as a plasticizer. The further addition of <=50wt% based on glyceride amount of 6-8C dialkyl azelate (one having a reduction in weight under heating at 190 deg.C for 30min of <=40wt%) improves the adhesivity.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vinylidene chloride copolymer extrusion molding composition suitable for food packaging films having improved inflation control properties, transparency and adhesion.

Taking advantage of its properties, vinylidene chloride copolymers are widely used as household wrap films and other food packaging materials.

This vinylidene chloride-based food packaging material is obtained by melt-extruding the composition, rapidly cooling it, and then forming it into an inflation film.It can be formed into a film by the inflation method without any industrial problems, has no food hygiene problems, and is a good product. In order to retain its value, the film must be transparent and have a good appearance.

As a conventional vinylidene chloride copolymer composition for extrusion molding for food packaging, epoxidized vegetable oil as a stabilizer and dibutyl sebaque as a plasticizer for melt extrusion) (DB8)
, dioctyl adipate (DOA), acetyltributyl citrate (muTBC), and the like are known. However, for example, compositions containing DBS and DOA have a large haze of 7 ilms and insufficient transparency, and AT
BC has unsatisfactory drawbacks in terms of adhesion, and furthermore, when conventional BC is melt-extruded and rapidly cooled in a water bath,
The plasticizer in this conventional composition is highly volatile and tends to bleed onto the surface of the extrudate immediately after melt extrusion, separating into oil droplets on the surface of the water bath, which are then adsorbed onto the surface of the extrudate again during rounding and subsequent inflation. There is a phenomenon in which dotted white spots are produced during the film formation process, which deteriorates the appearance of the film and reduces film transparency and gloss. This phenomenon is unique to vinylidene chloride copolymer extrusion molding compositions that are rapidly cooled after melt extrusion, and is particularly applicable to vinylidene chloride copolymer food packaging films (Ka), which require transparent and good appearance. It was an intermediate layer.

The present invention, Tomi et al., has developed a bi-9-dens copolymer composition which can be extruded into a wrapping material suitable for food packaging without such drawbacks and has good film-forming properties. When a specific substance is used as an additive to food packaging materials in place of conventional cleaners, there is no deterioration in appearance due to the appearance of white spots.
The inventors have discovered that it is possible to obtain a food packaging film with good transparency and wrap film adhesion with good film formability, and have thus arrived at the present invention.

That is, the present invention is a glycerin ester having a vinylidene chloride copolymer, an epoxidized vegetable oil, and an acyl group formed from a lower fatty acid having 2 to 6 carbon atoms and an acyl group formed from a higher fatty acid having 8 to 22 carbon atoms as a plasticizer. A cyclized vinylidene copolymer for extrusion molding, characterized in that it is blended with a glyceride or a dialkyl azelate whose alkyl group has 6 to 8 carbon atoms, prepared by forming 91 or more types selected from the following. It is a composition.

In the present invention, it is formed by esterifying at least one of the three hydroxyl groups of Glyceride's Gly7rin, which is blended into the bidenum chloride copolymer, with a higher fatty acid, and has nine acyl groups, and the remaining hydroxyl groups It is a mixture of 91 types of glycerin esters having tEtL and 7 yl groups formed by esterification of lower fatty acids, and more than 12 types of F1. When blending the 1119 composition with a vinylidene chloride copolymer and forming a blind film after rapid cooling, white spots appear on the extruded film, resulting in poor appearance and stretching. In order to avoid deterioration of film formability, the loss on heating at 190°C for 30 minutes in the measurement method described below is 40% by weight or less, or the heat loss at 150°C and 30% for the hydroplastic kneaded vinylidene copolymer sheet Preferably, the compound has a heat loss of 5% by weight or less. Even more preferably, the shear stress of a composition containing 1G weight % of vinylidene chloride copolymer is 145 x 10'dp#/m.
, the melt viscosity is in a practically preferable range lX10'f
fJl or less (vinyl chloride y copolymer body alone 20X10'
This shows the plasticizing effect that occurs when

The acyl group formed from a lower fatty acid having 2 to 6 carbon atoms is preferably acetic acid, and the acyl group formed from a higher fatty acid is preferably acetic acid. One type or a mixture of one or more types of glycerin esters having an acyl group formed from a fatty acid having 8 to 22 carbon atoms, preferably 10 to 1B, and particularly preferably 12 to 1B.

If the acyl group of glycide is below the above range, the weight loss on heating will be large, causing deterioration in the appearance of the stretched film and film formability.If it is above the above range, the melt viscosity will become impractical
This makes extrusion difficult and reduces the transparency of the film.

Specifically, diacetylcaprylglyceride, diacetylcaprylylglyceride, diacetyldecanoylglyceride, diacetyllaurylglyceride, diacetylmyristylglyceride, diacetylparylglyceride, diacetylstearylglyceride, diacetyleidylglyceride, diacetylerylglyceride, Examples include one or a mixture of one or more of rubionyl lauryl glyceride, diptanoyl lauryl glyceride, cicabroyl lauryl glyceride, and the like.

The blending amount of the glyceride of the present invention is 90% vinylidene chloride copolymer to improve extrusion moldability and film transparency.
The amount is preferably 1 to 15 parts by weight, particularly preferably 3 to 10 parts by weight.

Further, in the present invention, the dialkyl azelate whose alkyl group has 6 to 8 carbon atoms, which is added as a part of the glyceride content, is suitable for further improving the adhesion of the household wrap film. If the number of carbon atoms in the alkyl group is outside this range, the appearance and transparency of the film will deteriorate. A mixture of 91 or more alkyl groups selected from those having 6 to 8 carbon atoms may be used, but it is preferable that the weight loss on heating at d190°C for 30 minutes is 40% by weight or less.

In particular, diacyl azelate is preferably used. In addition, the blending amount is determined so that the film formability is not reduced.
It is preferable that the content of 9-do is 50% by weight or less.

As the cyclized vinylyzo copolymer used in the present invention, the usual ones known by Hiro are used, including vinylyzo chloride 770~
It is a copolymer consisting of 9s by weight and 5 to 30 weight% of a copolymerizable monomer. Because of its good film forming properties and melt extrusion processability, we measured the falling seconds t with an Ubbelohde viscosity needle for a solution with a cyclohexane concentration CP/-, and the falling seconds t@ of only the solvent ('/1o-1)/ Vinylidene chloride and vinyl chloride, acrylate in alkali having a reduced viscosity of α040 to α065 #/l, which indicates the size of the molecular weight determined by C.
Copolymers with at least one alkyl methacrylate are preferred.

The epoxidized vegetable oil used in this invention is a known and conventional epoxy stabilizer for vinylidene chloride copolymer extrusion processing. For example, epoxidized vegetable oils such as linseed oil, soybean oil, coconut oil, and linseed oil are suitable. The blending amount is a usual amount, and preferably 15 to 3 parts by weight per 100 parts by weight of the vinylidene chloride copolymer.

The composition of the invention can be obtained by conventional methods, such as feather pre-gourmet. It is obtained by heating and mixing in a Henschel ζ mixer or the like, and cooling and discharging the mixture. However, the glyceride used in the present invention may be added at any step before or during the polymerization of the vinylidene chloride copolymer, or in the trench for preparing the composition, as long as there is no reactant. Further, the dialkyl azelate used in the present invention may be mixed with glyceride and used simultaneously, or may be added separately like glyceride.

Furthermore, the composition of the present invention contains a resistance improver used in known food packaging materials, a coloring agent such as a dye or a pigment, a fat clouding agent,
Inorganic powders such as silica, lubricants, nucleating agents, oligomers such as polyester, polyesters such as MB8 resin, etc. can be added.

Also, depending on the application, it may be used in combination with conventional topical agents.

The composition O of the present invention can be extruded using a well-known melt extrusion technique. For example, extrusion is performed through a two-die squeegee of a screier extruder, and the tubular extrudate is passed through a first cooling water bath at room temperature or below, and then passed through a second heating bath at room temperature to about 50°C.
Inflate the two sets of pinch rollers by putting air between them.
The film can be formed by forming a film by the inflation process, which creates a stretched film by forming pulls, or it can also be formed by extruding from a T-guidure and rapidly cooling.

According to the above-described composition of the present invention, a food wrapping scissors film with excellent transparency can be obtained without causing white spots or deteriorating the appearance of the film when the film is formed after melt extrusion and rapid cooling. In particular, products containing glyceride and dialkyl azelate have no problems in film formability, film appearance, transparency, odor, or food hygiene, and the adhesion of household wrap films is extremely improved, making them suitable for food packaging films. can get.

Further details will be explained below with reference to Examples.Examples 1 to 10
．． Comparative Examples 1 to 5 The reduced viscosity obtained by suspension polymerization with a polymerization charge composition of 81% by weight of vinylidene chloride and 19% by weight of vinyl chloride was αo46.
#/y of 100 parts by weight of vinylidene chloride copolymer and 1! of epoxidized ama = m as a stabilizer! ! Addition amount of 1,
Glyceride mainly composed of diacetylated monolauryl glycerol as a plasticizer [BOEM G-002 manufactured by Riken Vitamin Co., Ltd.
(trade name)] were blended at 80° C. for 4 hours using a blade blender at the blending ratio of the addition amount shown in Table 1, and then cooled to 40° C. or lower to obtain SO compositions of Examples 1 to 1.

These compositions were then applied to a caliber 1 with a circular die.
Using an extruder with a diameter/length ratio (L/D ratio) of 220, melt extrusion was performed at an extrusion rate of 2404/Hr, immediately passed through a cooling water bath at 6°C, and then a second heating at 20°C. After passing through the bathtub, a bubble inflated with air is formed between two pairs of pinch rollers, and the ground expansion magnification is horizontal x vertical & 7 x 4.
．． Stretch 9g to S times, fold and wind up into a roll to a thickness of 10. 3. g (single thickness) of Examples 1 to 3 were prepared.

In addition, as Examples 4 to 10, the same glyceride and hexyl azelate DH2 (manufactured by San Kako Co., Ltd. D%) as in Examples 1 to 3 were used.
KIIi extrusion molding compositions were prepared in the same manner as in Examples 1 to 3, except that the plasticizers used in H2) and conventional compositions were added in the proportions shown in Table 2. In addition, wrap films of Examples 4 to 10 were prepared in the same manner as in Examples 1 to 3.

Next, as Comparative Examples 1 to 5, DBS (Diptilce J.
<Kate), ATBC (acetyl tributyl citrate) and DOA (dioctyl adipate) alone or in combination, the book of addition ratio in Table 1 is used instead of glyceride, and the stable side is other than the addition amount in Table J. are Examples 1 to 3
The extrusion molding composition was exploded in the same manner as above. Wrap films of Comparative Examples 1 to 5 were prepared using these in the same manner as Examples 1 to 3.

Evaluation items for the compositions of Examples 1 to 3 and 4 to 10 and Comparative Examples 1 to 5 above include the film formability of stretched films, the number of white spots on the films, and the degree of haze and adhesion of the obtained wrap films. To measure the sliding resistance value and film odor between the glass and film surfaces. The results are Tables 1 and 2
It was shown to. From the results in Table 1, it is clear that the composition of the present invention adheres easily.

Furthermore, from Table 2, it is clear that the films of Examples 4 and 10 are also extremely superior to conventional films, and are particularly suitable for use as household wrap films with extremely good adhesion to glass surfaces.

In addition, various properties of the plasticizers used in the above II Theory Examples and Comparative Examples were measured. Heat loss at 190℃ for 30 minutes,
Loss on heating of sheet kneaded at 150°C for 950 minutes and 160% of vinyl chloride lyso-y copolymer blend (blended with 10% plasticizer)
The results of the °C melt viscosity are 17.0% and 162% of glyceride, the main component of diacetyl lauryl glycerin used in the experiment.
and 0.8X 104ep, DHZ 9.8%,
247% and o, 5x1cr'ep, which is preferred for the present invention, whereas conventional
4%, 5.4% and α47X10'cp, ATBC
FiS 17%, Enterprise, 62% and 0.6 X 10'
t'P, DOA is 146%, 2.47% and α5
It was 10'ep.

In addition, the gas chromatography analysis results of the glyceride °C component of diacetyl lauryl glycerin used in the examples showed that the main component was 3α.
4%, low boiling point diacetyl acylglyceride with 6 to 12 carbon atoms) 145%, high boiling point diacetyl acylglyceride) 52.5% and monoacetyl diacylglyceride (acyl group with approximately 6 to 22 carbon atoms) 2Q, 6%
〇In addition, various measurement methods in Examples and Comparative Examples were performed as follows.

1. Plasticizer (1), Loss on Heating A plasticizer was placed in a Petri dish with an inner diameter of 65 cm, and the weight change was measured when the plasticizer was left in a constant temperature bath at 190° C. for 30 minutes.

(2) Kneaded sheet heat loss 100 parts by weight of a copolymer consisting of 80 parts by weight of vinylidene chloride and 20 parts by weight of vinyl chloride was blended with 10 parts by weight of a plasticizer at 80°C for 20 minutes using a Henschel mixer, and cooled. The obtained mixture was kneaded using a mixed wire roll at 140'C for 3 minutes at a roll spacing of t 5 fig, and the obtained kneaded product was hot pressed at 180"C to create a 400μ thick sheet. 50x50a heating loss for 30 minutes
Measurements were made for m test pieces.

(3) Melt viscosity (2) The resulting mixture was measured with a Koka type flow tester tester.

2. Glyceride Composition Analysis A sample was dissolved in roohexane and subjected to gas chromatography analysis using a heated gas chromatography at 150 to 540°C and a Dia Solid ZT column hydrogen flame detector.

3. Film forming properties: 10μ thick (single) in the same manner as described in Examples 1 to 3
, 10 rolled film rolls with a fold width of 1700 mm and a length of 1000 mm were manufactured, and the number of film ruptures per roll (pieces/roll) was determined from the number of film ruptures during inflation that occurred during this time. I asked for it.

4. Number of white spots generated When forming a blown film in the same manner as in Examples 1 to 3, the number of white spots generated on the film surface per minute when the folded film passes through a guide roller and is wound up. The number of mourning spots (pieces/min) was determined.

5. Slip resistance The stretched film obtained in the same manner as described in Examples 1 to 5 was left at room temperature for one month, and the film slit to the size of a household wrap film and rolled up was further left at room temperature for about two months. It was used as a sample. The measurement was carried out by pasting the wrap film uniformly on a horizontal support stand with a tape, and applying a load of 10
0t was placed and sheared off from a round glass plate (60 mm x), and the slip resistance value (6 am'') was determined.

6. Seal the glass cup filled with film odor water with cling film, heat it in the microwave for 3 minutes, and sense the film odor immediately after by 30 evaluators: A (no depth), B (slightly depth)
, it was judged as C (there is a strange odor).

Claims (2)

[Claims] (1) An acyl group formed from vinylidene chloride copolymer, epoxidized vegetable oil, lower fatty acid having 2 to 6 carbon atoms as a plasticizer, and high 1/Ik11 chain having 8 to 22 carbon atoms. 1. A cyclized vinylidene copolymer composition for extrusion molding, characterized in that it contains a glyceride formed by mixing one or more of glycerin esters having the following. (2) The vinylidene chloride copolymer composition according to claim 1, wherein a dialkyl azelate having an alkyl group having 6 to 8 carbon atoms is blended together with the glyceride as a plasticizer.