JPH09151290A - Vinylidene chloride polymer composition and its molded item - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a vinylidene chloride polymer compsn. which is resistant to discoloration or coloration and has improved thermal stability and heat resistance by compounding a vinylidene chloride polymer with an epoxidized 1,2-polybutadiene. SOLUTION: This vinylidene chloride polymer compsn. is prepd. by compounding 100 pts.wt. vinylidene chloride polymer having a vinylidene chloride unit content of 70-97wt.% and a reduced viscosity (in cyclohexanone in a concn. of 4g/l at 30 deg.C) of 0.035-0.080l/g with 0.5-10 pts.wt. epoxidized 1,2-polybutadiene having a number average mol.wt. of 800-1,200 and, if necessary, further with 0.05-2.5 pts.wt. fatty acid monoglyceride, 0.05-4 pts.wt. epoxy stabilizer, and 0.1-10 pts.wt. plasticizer. A molded item having a gel fraction of 0.5-50% is obtd. by forming the compsn. into an item having a thickness of 5-2,000μm and exposing the item to a radiation.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a vinylidene chloride polymer (hereinafter abbreviated as “PVDC”) molded article, and more specifically, it has little discoloration or coloring, and is excellent in thermal stability and heat resistance. It relates to molded products such as films and sheets. The PVDC molded product of the present invention is particularly suitable for food packaging.

[0002]

2. Description of the Related Art PVDC is a resin having a characteristic of oxygen gas barrier property. Conventionally, PVDC has been used as a packaging material for ham, sausage, various kinds of meat, etc., and PVDC alone or another thermoplastic resin has been laminated on it. Molded products such as films and sheets are widely used.

Such a film or sheet is usually formed into a bag shape or a tubular shape, and then sealed by a method such as heat sealing, impulse sealing or high frequency sealing to obtain a bag manufacturing product. Among the films and sheets used in this way, in order to obtain a film or sheet that can be sealed under a wider range of conditions, radiation such as an electron beam is applied in the manufacturing process. For example, when a film or sheet in which a PVDC layer and a polyethylene seal layer are laminated is irradiated with radiation such as an electron beam, PVD due to heat at the time of sealing is applied.
Deformation of the C layer (for example, the PVDC layer in the seal part is partially melted and thinned to have a non-uniform thickness) and the polyethylene layer is melt-cut (the polyethylene part is partially melted excessively in the seal part). , That the polyethylene layer is cut) can be prevented. The obtained molded product can be sealed in a wide range of conditions, and becomes a bag-manufactured product with little reduction in sealing strength.

However, irradiation with radiation causes PVD
The decomposition of C occurs, which may cause a problem that the film or sheet is discolored or colored. Packing contents such as ham, sausages or various meats in bag-shaped or tubular bag-shaped products obtained from such films and sheets may cause an influence of transfer of odor to the contents, and There is a problem that the image of the product is deteriorated and the consumer's willingness to purchase is impaired, and prevention of discoloration and coloring is strongly desired.

Heretofore, there has been reported a method of blending PVDC with a known heat stabilizer such as a hindered phenol compound, a hindered amine compound, a dialkylthiodicarboxylic acid ester or an antioxidant. Further, Japanese Patent Publication No. 5-18343 discloses a resin composition which is excellent in γ-ray resistance by adding a thioalcohol compound to a halogen-containing resin. Further, in Japanese Patent Laid-Open No. 8-67793, the present inventors propose a PVDC molded product with little discoloration or coloring and improved thermal stability and heat resistance.
Under such circumstances, development of vinylidene chloride-based polymer molded products with little discoloration or coloring and excellent in thermal stability and heat resistance, particularly films and sheets for food packaging, has been earnestly desired.

[0006]

DISCLOSURE OF THE INVENTION An object of the present invention is to improve the thermal stability and heat resistance of P with less discoloration and coloring.
It is to provide a VDC molded product.

[0007]

Means for Solving the Problems The present inventors have made various studies in order to achieve the above-mentioned objects.
And epoxy group-containing 1,2-polybutadiene (hereinafter referred to as “P
The present invention has been completed by finding that a composition containing "BD") and a molded product obtained from the composition have little discoloration or coloring and are excellent in heat stability and heat resistance. Specifically, there are provided a composition containing 100 parts by mass of PVDC and 0.5 to 10 parts by mass of epoxy group-containing 1,2-polybutadiene, and a molded product formed from the composition. Also provided is a molded article having at least a layer made of the above composition (hereinafter abbreviated as PVDC composition). Further, according to the present invention, there is provided a molded product in which at least a layer made of the PVDC composition is irradiated, and a molded product having a layer made of the PVDC composition, which is irradiated, and a layer made of a thermoplastic resin. Provided.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. [Vinylidene Chloride Copolymer] PVDC Used in the Present Invention
Is preferably 3 to 30 mass% of a monomer copolymerizable with 70 to 97 mass% of vinylidene chloride, and more preferably 5 to 5 mass% of a monomer copolymerizable with 80 to 95 mass% of vinylidene chloride.
It is a copolymer composed of 20% by mass. If the content of vinylidene chloride is too small, the gas barrier properties of the polymer to be obtained such as oxygen and water vapor will be deteriorated. On the contrary, if it is too large, the melting point will be too high and thermal decomposition during melt molding will be likely to occur.
When the vinylidene chloride content is in the range of 80 to 95% by mass, the resulting polymer has a good balance between gas barrier properties against oxygen and water vapor and moldability, and is more preferable.

Examples of monomers copolymerizable with vinylidene chloride include vinyl halides such as vinyl chloride; alkyl acrylates such as methyl acrylate, ethyl acrylate, butyl acrylate, octyl acrylate, and lauryl acrylate. Ester; Methyl methacrylate, ethyl methacrylate, methacrylic acid alkyl ester such as butyl methacrylate; acrylic acid, methacrylic acid, maleic acid, itaconic acid, maleic anhydride, itaconic anhydride, maleic acid alkyl ester, itaconic acid alkyl ester, Acrylonitrile, vinyl acetate, ethylene,
Examples include propylene, isobutylene and butadiene. Further, the copolymerizable monomer may be one or more kinds. Of these, a copolymer containing vinylidene chloride and vinyl chloride is preferable.

The reduced viscosity is an index showing the molecular weight of the polymer, and when the cyclohexanone is used as a solvent and the concentration is 4 g / liter (g / L) and the reduced viscosity is usually from 0.035 to 0. The range of 080 L / g, preferably the range of 0.038 to 0.065 L / g is desirable. If the reduced viscosity is less than 0.035 L / g, the molding process is difficult because the molecular weight is too low.
If it exceeds 0 L / g, the molecular weight becomes too high and melt molding becomes difficult. Reduced viscosity 0.038-0.065L /
Polymers in the range of g (hereinafter, the unit of reduced viscosity is omitted) are suitable from the viewpoint of physical properties and processability. Among them, PVDCs having a reduced viscosity of 0.045 or more are particularly preferable in view of physical properties such as retort resistance and cold resistance. PVD
If C is a mixed system, PVD with reduced viscosity of 0.048 or more
PVD with C50 mass% or more and reduced viscosity less than 0.048
Less than C50 mass% is preferable. Reduced viscosity is 0.048 ~
PVDC in the range of 0.08 and 0.035-0.045
A mixed resin with PVDC in the range of less than is more preferable.
Further, it is more preferable that the latter PVDC is contained in an amount of 3 to 25% by mass. In the case of the mixed system, the physical properties such as retort resistance and cold resistance and the extrusion processability are improved in a more balanced manner by the combination with the composition of the present invention.

[PBD] The PBD used in the present invention is
A compound obtained by epoxidizing 1,2-polybutadiene, which is a compound containing an epoxy group and a vinyl group as an active atomic group in the molecule. PBD has been conventionally used as a coating agent or a laminating agent by utilizing the reactivity of an epoxy group or a vinyl group, or
It is used as a resin modifier or sealing agent by mixing it with a thermoplastic resin. However, it has not been known that a molded article made of the composition of the present invention, particularly a molded article irradiated with radiation, has little discoloration or coloring, and the thermal stability is improved. It is a thing.

The PBD used in the present invention has a number average molecular weight in the range of 800 to 1200, preferably 900 to 110.
It is in the range of 0. If the number average molecular weight is too low, bleeding of PBD and deterioration of molding processability are likely to occur in the process of producing a composition or a molded product, while if the number average molecular weight is too high, uniform mixing with PVDC is maintained. It becomes difficult to be done. A PBD having a number average molecular weight in the range of 900 to 1100 is preferable from the viewpoints of physical properties, handleability, and availability of the obtained molded product. The ratio (molar ratio) of the epoxy group and the vinyl group contained in the PBD molecule is not limited in carrying out the present invention, but the ratio of the vinyl group 2 to the epoxy group 1 is generally preferable. Is.

[Glycerin Monofatty Acid Ester] The glycerin monofatty acid ester (hereinafter abbreviated as “GME”) preferably used in the present invention is a GME composed of a fatty acid having 16 to 22 carbon atoms. P containing PBD
By further including GME in the VDC composition,
Compared with a PVDC composition containing no GME, it is characterized in that the effect of preventing discoloration and coloring and the effect of improving thermal stability are more excellent. Examples of GME include glycerin monostearate, glycerin monopalmitate, glycerin monooleate, glycerin monobehenate and the like. These may be used alone or in combination.

Glycerin monostearate, glycerin monopalmitate and glycerin monobehenate are preferred from the viewpoints of preventing discoloration and discoloration, and improving heat stability. Among them, glycerin monostearate is particularly preferred. It is also suitable in terms of handling. The GM used in the present invention
If E is less than 30% by mass, it may contain glycerin difatty acid ester or glycerin trifatty acid ester composed of fatty acid having 16 to 22 carbon atoms.

[Composition] The PVDC composition of the present invention is
PVDC is preferably 100 parts by mass and PBD is preferably 0.5 to 10 parts by mass, more preferably 1 to 9 parts by mass and 0.05 to 2.5 parts by mass of GME in the above composition, preferably 0. 1 to 1.7 parts by mass is included.
When the content of PBD is low, the effect of preventing discoloration or coloring of the molded article, which is the object of the present invention, is not sufficient, while when the content of PBD is too high, the molding process becomes difficult and the resulting molded article becomes cloudy. Problems such as are unlikely to occur. The content of PBD is preferably in the range of 0.5 to 10 parts by mass from the viewpoint of molding processability, the effect of preventing discoloration and coloring, and physical properties such as strength. Particularly in the range of 1 to 9 parts by mass, the balance with such workability and physical properties becomes better. Further, when the content of GME is less than 0.05 parts by mass, it is difficult to obtain the effect of preventing discoloration or coloration and the effect of further improving thermal stability, as compared with the PBD-containing PVDC composition containing no GME. On the other hand, if the GME content exceeds 2.5 parts by mass, problems such as difficulty in molding and whitening of the obtained molded product occur. The content of GME is preferably in the range of 0.1 to 1.7 parts by mass in terms of molding processability, an effect of preventing discoloration and coloring, and physical properties such as strength.

The PVDC composition of the present invention may contain conventionally known epoxy stabilizers, auxiliaries, plasticizers and the like depending on the purpose. As a preferable blending example, 0.05 to 4 parts by mass of an epoxy vegetable oil and 0.1 to 10 parts by mass of a plasticizer are blended with 100 parts by mass of PVDC. As an epoxy stabilizer,
For example, an epoxidized stabilizer obtained by epoxidizing linseed oil, soybean oil, coconut oil, safflower oil, sunflower oil, cottonseed oil, sunflower oil, etc .; epoxidized fatty acid monoester represented by octyl octyl stearate; unsaturated Examples thereof include epoxidized fatty acid diesters obtained by epoxidizing fatty acid glycol esters; alicyclic epoxides represented by epoxy hexahydrophthalic acid esters, and the like. Among these, epoxidized vegetable oil is preferable from the viewpoint of heat stability and food hygiene. Further, ethylenediaminetetraacetic acid or a salt thereof, at least one salt of a non-alkene weak acid, and optionally triethylene glycol bis-3- (3-tert-butyl-4-hydroxy-5-methyl-phenyl) propionate, vitamin E, Another example is PVDC obtained by polymerizing vinylidene chloride in the presence of at least one auxiliary selected from the group of alkyl thiodipropionates. The preferable range of the addition amount is 0.0005 to 0.2 part by mass of ethylenediaminetetraacetic acid or a salt thereof and 0.001 to 1 part by mass of at least one salt of a non-alkene weak acid, and triethylene glycol bis-3 as necessary. -(3-tert-butyl-4-hydroxy-5-methyl-phenyl) propionate 0.0005-0.5 parts by mass, vitamin E
PVDC obtained by polymerizing vinylidene chloride in the presence of at least one auxiliary selected from the group consisting of 0.0005 to 0.2 parts by mass and thiodipropionic acid alkyl ester moiety 0.0005 to 0.2 parts by mass. . At least one salt of the non-alkene weak acid used in these is preferably a phosphate salt or a derivative thereof. By using the stabilizer or auxiliary agent having such a constitution, it is effective in improving the color tone of the obtained molded product.

Further, the plasticizer is not particularly limited as long as it is a plasticizer used in usual PVDC molding.
Specific examples of the plasticizer include aliphatic 2 such as dioctyl adipate, dioctyl sebacate and dibutyl sebacate.
Basic acid ester; hydroxy polycarboxylic acid ester such as tributyl citrate and acetyl tributyl citrate; glycerin fatty acid ester plasticizer such as glyceride containing diacetylmonolauryl glycerin as a main component;
Examples include polyester plasticizers. PVDC includes at least one selected from ethylene and vinyl acetate copolymers, ethylene and acrylic acid, methacrylic acid or their alkyl ester copolymers, and MBS resin.
You may mix 0.1-20 mass parts of kinds of polymers (A). In addition, PVDC contains titanium oxide pigment of 0.10 to 1
0 parts by weight can be included. Titanium oxide pigments are effective in preventing discoloration of food contents such as sausages due to ultraviolet rays, but increase the adhesion decomposition at the die outlet. But,
Combined with the use of PBD and the use of a vacuum hopper, sticking decomposition is effectively reduced and large amounts can be added. The PVDC composition of the present invention contains, in a range that does not impair the object of the present invention, a colorant such as a pigment known as an additive for food packaging, a stabilizer such as spoilage and antioxidant, an inorganic powder such as silica, a lubricant, MBS resin or the like can be added.

The above composition can be prepared by mixing the respective components by a conventional method, for example, using various mixers such as a blender, a Henschel mixer and a kneader. In addition, each component may be appropriately added and mixed during or after the polymerization of PVDC. PVDC
And at least one polymer (A) are generally mixed at a temperature of 60 ° C. or lower.

[Radiation Irradiation] The PVDC composition of the present invention may be molded by a usual method such as melt molding and, if necessary, irradiated with radiation to obtain a molded product. Further, a radiation-exposed multi-layer molded product having a layer made of the PVDC composition of the present invention and a layer made of a thermoplastic resin can also be used. In the present invention, at the time of irradiating with radiation, it is preferable that at least the layer comprising the PVDC composition is irradiated with radiation. Irradiation has the effect of cross-linking the layer made of the PVDC composition of the present invention and further improving the heat resistance.

For irradiation with radiation, α rays, β rays, electron rays, γ
Known radiation such as X-ray and X-ray can be used,
From the viewpoint of the cross-linking effect before and after irradiation, electron beams and γ rays are preferable, and among them, electron beams are convenient in terms of handleability in producing a molded product. The radiation irradiation conditions may be appropriately set according to the target molded article. For example, in the case of an electron beam, the acceleration voltage is 250 to 5
Range of 00 kilovolt (hereinafter abbreviated as "kV"), irradiation dose is 10 to 200 kilogray (hereinafter abbreviated as "kGy")
Is preferable, and in the case of γ rays, the dose rate is 0.
The range of 05-3 kGy / hour is preferable.

In the present invention, the degree of radiation irradiation when the molded product is irradiated with radiation can be evaluated by the gel fraction of the layer comprising the PVDC composition (the measuring method will be described later). The gel fraction of the layer formed of the PVDC composition in the molded product of the PVDC composition of the present invention alone or in the multilayer molded product is preferably in the range of 0.5 to 50%, more preferably 0.5 to 40%. Range, most preferably 0.5-30%. When the gel fraction is less than 0.5%, the effect of improving the heat resistance of the molded product is not sufficient, and
When the gel fraction exceeds 50%, there is a problem in producing a molded product such as long irradiation, and the mechanical properties of the resulting molded product may deteriorate. The gel fraction in the range of 0.5 to 40% is convenient from the viewpoint of performance such as manufacturability, heat resistance, and mechanical properties, and particularly, the gel fraction is 0.
The range of 5 to 30% is convenient in terms of practical use.

[Molded Product] A molded product comprising the composition of the present invention is molded and manufactured by a usual method. The PVDC composition may be a single molded product or a multi-layered molded product. In the case of a molded product of the PVDC composition alone, for example, the composition may be hot pressed to produce a film or sheet, or the composition may be melt extruded and the extrudate obtained may be formed into a film or sheet by an inflation method. The above composition can be melt-extruded by the T-die method, and a film or sheet can be produced from the resulting extrudate. Further, an extrusion method in which the PVDC composition is supplied to an extruder via a vacuum hopper is effective, and the extrusion processability and color tone are improved. In particular, in the case of a vinylidene chloride-based copolymer having a reduced viscosity, for example, a relatively high melt viscosity of 0.045 or more, it is more effective to supply it to the extruder via a vacuum hopper. Even if PVDC contains recycled (recycled) resin, it is effective as the composition of the present invention. Here, the recycled resin is a molded product of a resin containing PVDC or a recovered product generated at the time of processing. For example, PVDC flume, sheet, or other nonstandard product, loss generated during molding of slit scrap, etc. Includes mixing and reusing the crushed product. In addition, the polymer (A) may be newly mixed and used in a PVDC layer, a recycled PVDC crushed product, or a mixed product of both, or the like.
It may be a multi-layer molded product in which the recycled resin is an independent layer. Alternatively, in special cases, the extrusion processability can be further improved by mixing and using a pulverized product of a multilayer film containing them. In addition, a multilayer resin product such as a multilayer film or a multilayer sheet can be manufactured by laminating a thermoplastic resin on the film or sheet thus obtained and, if necessary, using an adhesive. Alternatively, a plurality of extruders are used to coextrude the composition of the present invention, a thermoplastic resin and, if necessary, an adhesive, and the resulting extrudate is subjected to an inflation method or a T-die method to form a multilayer film or a multilayer film. Multilayer molded products such as sheets can be manufactured. Furthermore, the above-mentioned film or sheet, or the multilayer film or multilayer sheet can be used to mold into a container or the like to obtain a molded article. Further, the film obtained in the present invention can be retort processed. In particular, when the composition of the present invention is used as an intermediate layer in the form of a multilayer film, it is hard to be affected by the bleeding of PBD even if it is radiation-crosslinked,
The prevention of discoloration and coloring of VDC and the thermal stability are remarkably improved.

The molded product of the PVDC composition alone or the multilayer molded product of the present invention may be unstretched or stretched. The stretched product may be uniaxially stretched or biaxially stretched. The draw ratio can be appropriately determined according to the purpose of the molded product, and is usually 1.5 to 0.5 in both the longitudinal and transverse directions.
About 7 times is convenient. The stretched molded product can be made into a film having heat shrinkability.

In the present invention, irradiation is a step of producing a molded product of a PVDC composition alone or a multilayer molded product, and a film or sheet is formed from an extruded product obtained by melt-extruding the PVDC composition of the present invention. It is performed in the process until it becomes. Specific examples include irradiation of an extrudate before inflation, irradiation of radiation during inflation, irradiation of a stretched product after inflation, and unstretched product after extrusion with a T-die. Examples thereof include those that are irradiated with radiation, those that are simultaneously subjected to stretching and irradiation, and those that are irradiated with radiation after stretching. Among these, those that irradiate the extrudate before inflation, those that irradiate the stretched product after inflation, those that irradiate the unstretched product after extrusion with a T-die, those that irradiate after stretching. Etc. are preferable from the viewpoint of operation when they are manufactured.

The multi-layer molded article may be any article as long as it comprises a layer made of the PVDC composition of the present invention and a layer made of a thermoplastic resin. The thermoplastic resin used and the stacking order are appropriately determined according to the purpose. be able to. Further, a known polyester film in which paper, aluminum foil, silica or the like is vapor-deposited may be added. Depending on the resin used and the stacking order, the adhesive force between the layers to be stacked may not be sufficient. In such a case, a known adhesive resin (adhesive) such as a modified polyolefin or an ionomer resin described later.
Can be used for strong adhesion.

As the thermoplastic resin used in the present invention, known resins such as olefin polymers, amide polymers and polyesters can be used. Examples of the olefin polymer include homopolymers and copolymers of olefins, copolymers of olefins with other copolymerizable monomers such as vinyl monomers, and modified polymers thereof. can do. Specifically, high-density polyethylene, low-density polyethylene, linear low-density polyethylene (hereinafter abbreviated as "LLDPE"), linear ultra-low density polyethylene (hereinafter abbreviated as "VLDPE"), polypropylene, ethylene-propylene Copolymer, ionomer resin, ethylene / vinyl acetate copolymer (hereinafter abbreviated as "EVA"), ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer (hereinafter abbreviated as "EMAA"), ethylene / acrylic Methyl acid copolymer, ethylene / methyl methacrylate copolymer, modified polyolefin (for example,
Such as olefin homopolymers or copolymers with unsaturated carboxylic acids such as maleic acid and fumaric acid, and reaction products with acid anhydrides, esters or metal salts). The above olefin copolymers may be used alone or in combination of two or more. Among these, VL produced using Ziegler-Natta catalyst or metallocene catalyst
DPE, LLDPE, EVA, EMAA, ethylene / acrylic acid copolymer and the like are preferable from the viewpoints of physical properties such as flexibility, heat shrinkability and sealability.

As the amide polymer, nylon-6 (polycapramide), nylon-66 (polyhexamethylene adipamide), nylon-610 (polyhexamethylene sebacamide), nylon-12 (lauryl lactam) are used. Ring-opening polymer), nylon-6 / 66 (copolymer of ε-caprolactam and hexamethylene adipamide), nylon-6 / 610 (copolymer of ε-caprolactam and hexamethylene sebacamide), nylon- 6/12 (ε
-Copolymer of caprolactam and lauryllactam), nylon-6 / 66/610 (copolymer of ε-caprolactam, hexamethylene adipamide and hexamethylene sebacamide), nylon-6 / 66/12 (ε- Copolymer of caprolactam, hexamethylene adipamide and lauryl lactam), nylon-MXD6 (polymethaxylylene adipamide), nylon-6I / 6T (copolymer of hexamethylene isophthalamide and hexamethylene terephthalamide) And the like. Of these, nylon-6 / 66 and nylon-6 / 12 are preferable in terms of moldability, and nylon-MXD6 is preferable in terms of oxygen barrier property. The amide polymers can be used alone or in combination of two or more. As the polyester, for example, polyethylene terephthalate, polybutylene terephthalate, a copolymer of ethylene terephthalate and ethylene isophthalate, or the like can be used.

In the multilayer molded article of the present invention, examples of the layer structure include the following. (1) PVDC composition layer / adhesive layer / olefin polymer layer, (2) PVDC composition layer / adhesive layer / amide polymer layer, (3) olefin polymer layer / adhesive layer / PV
DC composition layer / adhesive layer / olefin polymer layer,
(4) amide polymer layer / adhesive layer / PVDC composition layer / adhesive layer / amide polymer layer, (5) olefin polymer layer / adhesive layer / PVDC composition layer / adhesive layer / Amide polymer layer, (6) olefin polymer layer / adhesive layer / PVDC composition layer / adhesive layer / amide polymer layer / adhesive layer / olefin polymer layer, (7) olefin polymer layer Combined layer / olefin polymer layer / adhesive layer / PVDC composition layer / adhesive layer / olefin polymer layer / olefin polymer layer.

Among the above layer constitutions, the following can be exemplified as preferable ones. (8) VLDPE layer / EMAA layer / adhesive layer / PVDC
Composition layer / adhesive layer / EMAA layer / VLDPE layer,
(9) VLDPE layer / EMAA layer / adhesive layer / PVDC
Composition layer / adhesive layer / EVA layer / VLDPE layer, (1
0) VLDPE layer / EVA layer / adhesive layer / PVDC composition layer / adhesive layer / EVA layer / EVA layer, (11) EVA
Layer / EVA layer / adhesive layer / PVDC composition layer / adhesive layer / EVA layer / EVA layer.

A molded article made of the composition of the present invention is PVD.
In the case of a single layer of the C composition, the thickness is preferably 5-20.
The range is 00 μm, more preferably 10 to 1000 μm, and most preferably 10 to 120 μm.
When the thickness is less than 5 μm, the oxygen gas barrier property is largely deteriorated, and when the thickness exceeds 2000 μm, the obtained molded product becomes expensive and it becomes impossible to form a flexible packaging material. I have a problem. The thickness is
The range of 10 to 1000 μm is preferable from the viewpoint of the above-mentioned manufacturing and performance balance, and the range of 10 to 120 μm is particularly convenient from a practical viewpoint.

In the case of a multilayer molded article, the thickness is preferably in the range of 10 to 3000 μm, more preferably 15 to 3000 μm.
In the range of 2000 μm, most preferably 20-250 μm
Range. When the thickness is less than 10 μm, it is difficult to balance the oxygen gas barrier property and impact strength, while when the thickness exceeds 3000 μm, for example, secondary processing for molding a container or the like from the obtained film or sheet. Sex becomes difficult. The thickness is 15 to 200 in terms of moldability and physical properties.
The range of 0 μm is preferable, and the range of thickness of 20 to 250 μm is particularly preferable from the practical point of view. And the thickness of the PVDC composition layer in the multilayer molded article is preferably 2 to 600.
It is in the range of μm, more preferably in the range of 3 to 500 μm, and most preferably in the range of 4 to 50 μm. 2μ thick
When the thickness is less than m, there is a problem in oxygen gas barrier property, while when the thickness exceeds 600 μm, the obtained molded product becomes expensive and the secondary processing becomes difficult. From the viewpoint of production and performance, the thickness of the PVDC composition layer in the multilayer molded article is preferably in the range of 3 to 500 μm, and particularly 4 to 4 in terms of practical use.
A range of 50 μm is suitable.

[Use of Molded Product] A molded product of the composition of the present invention, for example, a film, a sheet or a container can be used as a packaging material for foods and pharmaceuticals, and in particular, ham, sausage or Most suitable for food packaging such as various kinds of meat. It can be used in a suitable form depending on the intended packaging such as a bag, a cylinder or a dish. Further, it is also suitably used for retorts.

The molded product of the composition of the present invention is obtained by using easily available raw materials and by irradiation with radiation, if necessary, and is excellent in heat stability and heat resistance with little discoloration or coloring. It becomes a molded product. The obtained molded product is
For example, it can be used in various forms as a packaging material depending on the purpose.

[0034]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples. The methods for measuring physical properties and materials used (resin and additive) used in the present invention are as follows.

<Physical property measuring method> (1) Discoloration or degree of coloring Σ80 Color Meas manufactured by Nippon Denshoku Industries Co., Ltd.
uring System, the sample color difference (L
*, A *, b *) were measured. In case of press sheet,
The number of stacked samples was set to 1 for measurement. In the case of a tube film, the number of samples to be stacked is set to 10 in consideration of the appearance of several stacked films before being used for packaging.
It was measured as a sheet. The L * value means lightness, and a larger value indicates a direction in which the brightness is increased (whitened), and a smaller value indicates a direction in which the darkness is increased (blackened). The a * and b * values mean the chromaticity representing hue and saturation, and a *
The larger the positive value, the stronger the redness, and the larger the negative value, the stronger the greenness. The b * value indicates a direction in which the larger the positive value is, the stronger the yellowness is, and the larger the negative value is, the stronger the bluishness is.

(2) Measurement of gel fraction In the case of a single molded product, about 70 mg of a sample is precisely weighed and used as the sample mass. To this, 10 ml of tetrahydrofuran was added, and the mixture was kept at 60 ° C. for 2 hours, then filtered to collect undissolved matter, dried and weighed. It was calculated as a percentage from the dry mass of the undissolved material with respect to the mass of the added sample. In the case of a multi-layer molded product, the layer of the PVDC composition was peeled off, and this was used as a sample and measured in the same manner as above. (3) Oxygen permeability Using a oxygen control device OXTRAN-100 manufactured by Modern Control Co., Ltd., a multilayer molded article was prepared with 30
The measurement was carried out under conditions of ° C and 100% relative humidity. (4) Interlayer adhesion force Tensilon RTM-1 tensile tester manufactured by Orientec
00 was used to measure the interlayer adhesion of the multilayer molded article. That is, a sample with a width of 15 mm and a length of 100 mm is cut out from the multilayer molded product, and 85 m from one end in the length direction of the sample.
m was left, and the PVDC layer and the thermoplastic resin layer were peeled off from the other end up to 15 mm to prepare a test piece having a 15 mm length "grip margin" at one end. Then, the "grip margin" of the test piece was fixed to the tensile tester, and the pulling speed was 20%.
The laminated portion (85 mm) of the test piece was peeled at 0 mm / min to determine the strength required for peeling (g / 15 mm width). The average value for 5 samples was used.

(5) Sealing strength The piercing strength of the heat-sealed portion was evaluated. That is, from the inside of a 400 mm long and 400 mm wide bag (opened on the opposite side of the sealing portion) obtained by heat-sealing in a direction substantially perpendicular to the film take-up direction, along the seal line, as a lubricating oil. After applying, the diameter of the tip connected to the load cell made by Orientec Co., Ltd. is 1
The seal part was punched out from the inside of the bag with a punching rod having a 0 mm ball, and the strength (kg) at the time of punching out was read. Three points were punched out from one bag, and this was performed for ten bags, and the punching strengths at 30 points were averaged together. (6) Transparency Nippon Denshoku Industries Co., Ltd. Σ80 Color Meas
The haze (haze value;%) of the sample was measured using the Uring System. The smaller the haze value,
The direction in which the transparency is improved is shown, and the larger the value is, the worse the transparency is.

<Resin Material> (1) PVDC A copolymer composed of 82% by mass of vinylidene chloride and 18% by mass of vinyl chloride (reduced viscosity = 0.056 L / g, hereinafter referred to as “P”).
A copolymer composed of 95% by mass of vinylidene chloride and 5% by mass of methyl acrylate (reduced viscosity = 0.039 L / g, hereinafter abbreviated as "PVDC-2") was used. (2) VLDPE Moretec V0398CN manufactured by Idemitsu Petrochemical (Density =
0.907 g / cm ³ , melting point = 119 ° C.) was used. (3) EMAA Nucrel AN421 manufactured by DuPont Mitsui Polychemicals
7-1C was used. (4) Resin for Adhesive Evatate PC-149 (vinyl acetate content = 15% by mass) manufactured by Sumitomo Chemical Co., Ltd. was used.

<Additives> (1) PBD Epoxidized 1,2-polybutadiene Adeka Sizer BF-1000 (number average molecular weight: 1000) manufactured by Asahi Denka Co., Ltd.
It was used. (2) Glycerin monostearate Rikemar S-100 manufactured by Riken Vitamin Co. was used. (3) Epoxidized linseed oil Epoxidized linseed oil manufactured by Asahi Denka Co., Ltd. Adeka Sizer O-
180A was used. (4) Dibutyl sebacate Dibutyl sebacate DBS manufactured by Daihachi Chemical Co., Ltd. was used.

[Examples 1-9, Comparative Examples 1-10] 100
The amount of PB shown in Table 1 with respect to parts by mass of PVDC-1
D, epoxidized linseed oil as an epoxy stabilizer 1.0
20 parts by weight at 60 ° C. using a Henschel mixer.
The mixture was mixed for 1 minute and aged at room temperature for 3 days to prepare a compound. Use this compound with a diameter of 40φ (L / D
= 24) extruder, resin temperature 150 ° C, discharge rate 1
The mixture was melt-kneaded at 20 g / min, and the extrudate was cooled in a water bath at 18 ° C to form a strand. Then, each composition was prepared by crushing the strands into pellets. The composition thus obtained was preheated at 150 ° C. for 1 minute using a compression molding machine, and then pressed for 1 minute (at 50 MPa).
a) and then rapidly cooled to prepare an amorphous press sheet having a thickness of 200 μm.

Next, as an electron beam irradiation device, NHV E
The sheet was irradiated with an electron beam using PS-500-65-SS under the following conditions. Using the sheet thus obtained, the color difference (L *, a *, b *) for evaluating the degree of discoloration or coloring, gel fraction and transparency (cloudiness value) were measured. The results are summarized in Table 1. Electron beam irradiation conditions Irradiation temperature 30 ° C. Irradiation atmosphere Air Acceleration voltage 300 kV Irradiation dose 20, 40, 60 kGy Among the sheets obtained by using the above composition, those not subjected to electron beam irradiation are shown in Table 1. It is shown as “irradiation dose 0 kGy”.

[0042]

[Table 1]

As can be seen from Table 1, for example, Example 1 has a smaller b * value and a reduced yellow tint, as compared with the corresponding Comparative Example 1, as is apparent from the sheet of the present invention (Example It can be seen that in Examples 1 to 9), the degree of discoloration or coloring is improved as compared with the corresponding Comparative Example. From this, PB
D has the effect of preventing discoloration or coloring due to electron beam irradiation. When the amount of PBD added is small as in Comparative Examples 5 to 7, there is no effect of preventing coloring or discoloration due to electron beam irradiation. In addition, in Comparative Examples 8 to 10, the amount of PBD added was excessive, and thus the sheet was clouded, and there was a problem in use as a sheet.

[Examples 10 to 12, Comparative Example 11] 100
2 parts by weight of PBD and GME for PVDC-1 by weight.
As glycerin monostearate 0.5 parts by mass, as epoxy stabilizer epoxidized linseed oil 1.0
A PVDC composition was prepared in the same manner as in Example 1, except that 0.86 parts by mass of dibutyl sebacate was added as a plasticizer. Then, the PVDC composition, VLDPE, EMAA and adhesive resin thus obtained were mixed with 6
PVD was coextruded into a tube with the following layer structure using a single extruder and quenched with cooling water at 8 ° C.
A tube in which the C composition layer was substantially amorphous was obtained. Flatten this tube with a pinch roller and fold 1
It was a 36 mm unstretched parison. Then, from the surface of this unstretched parison, using the electron beam irradiation apparatus used in Example 1, an irradiation dose of 100 kGy and an acceleration voltage of 300 kV.
Electron beam irradiation was performed at. After that, put the parison at about 85 ° C.
Was heated with warm water and stretched 3 times in both length and width by an inflation method to produce a tube film having a folding width of 408 mm. Furthermore, using this tube film, heat seal it at a right angle to the take-up direction to obtain a length of 400 m.
A bag having a size of m and a width of 408 mm and having an opening on the opposite side of the heat-sealed portion was manufactured (Example 10).

A tube film and a bag were produced in the same manner as in Example 10 except that PBD was changed from 2 parts by mass to 5 parts by mass in Example 10 (Example 11).
Further, a tube film and a bag were produced in the same manner as in Example 10 except that PBD was changed from 2 parts by mass to 9 parts by mass in Example 10 (Example 12). On the other hand, as a comparative example, a tube film and a bag were produced in the same manner as in Example 10 except that the PVDC composition prepared in Comparative Example 1 was used (Comparative Example 11). Oxygen permeability, color difference (L *, a *, b *),
Interlayer adhesion, transparency (haze value) and gel fraction,
The puncture strength (seal strength) of the sealed portion was measured using a bag. The results are shown in Tables 2 and 3.

<Layer constitution> VLDPE layer (outermost layer) / EM
AA layer (outer layer) / adhesive layer / PVDC composition layer / adhesive layer / EMAA layer (inner layer) / VLDPE layer (innermost layer) <thickness of each layer (μm)> unstretched parison 27 (outermost layer) / 189 / 13.5 / 63 / 13.5 /
90/90 (innermost layer) Film 3 (outermost layer) /21/1.5/7/1.5/10/10
(Innermost layer)

[0047]

[Table 2]

[0048]

[Table 3]

[Examples 13 to 21, Comparative Examples 12 to 15]
With respect to 100 parts by mass of PVDC-2, the amount of PBD shown in Table 4 and epoxidized soybean oil 1.
5 parts by mass, 1.0 part by mass of epoxidized linseed oil, and 1.0 part by mass of dibutyl sebacate as a plasticizer were added to prepare a composition in the same manner as in Example 1 to prepare an amorphous press sheet. , Electron beam irradiation was performed. The color difference (L *, a *, b *) and the gel fraction were measured using the sheet thus obtained. The results are summarized in Table 4.

[0050]

[Table 4]

Table 4 shows PVD having different resin constitution (monomer constitution) for preventing discoloration or coloring due to electron beam irradiation of PBD.
It is shown that C is also effective.

[0052]

INDUSTRIAL APPLICABILITY The PVDC molded product of the present invention has little discoloration or coloring, is excellent in heat stability, seal strength and heat resistance, and is optimal as a packaging material for foods, pharmaceuticals and the like.
The PVDC molded product of the present invention can be used as a film, a sheet, a container, or the like.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location B65D 85/50 B65D 85/50 B C08J 3/28 CEV C08J 3/28 CEV 5/18 CEU 5 / 18 CEU 7/00 CEV 7/00 CEV 305 305 C08K 5/10 KJV C08K 5/10 KJV C08L 63/08 NJN C08L 63/08 NJN // C08G 59/20 NHV C08G 59/20 NHV (C08L 27/08 63 : 08)

Claims (11)

[Claims] 1. A composition comprising a vinylidene chloride polymer and an epoxy group-containing 1,2-polybutadiene. 2. 100 parts by mass of vinylidene chloride polymer and 0.5 to 1 of epoxy group-containing 1,2-polybutadiene.
0 parts by weight. 3. The composition according to claim 1, further comprising 0.05 to 2.5 parts by mass of glycerin monofatty acid ester having 16 to 22 carbon atoms. 4. The composition according to claim 1, wherein the vinylidene chloride polymer contains a recycled resin. 5. A molded product comprising the composition according to claim 1. 6. A molded article having at least one layer comprising the composition according to any one of claims 1 to 4. 7. The molded product according to claim 5, which comprises a layer composed of at least one thermoplastic resin selected from the group consisting of an olefin polymer and an amide polymer. 8. The molded product according to claim 5, wherein at least a layer made of a vinylidene chloride polymer composition is irradiated with radiation. 9. The molded product according to claim 7, wherein at least a layer made of a thermoplastic resin is irradiated with radiation. 10. The molded product according to claim 8, wherein the gel fraction of the layer made of the vinylidene chloride polymer composition irradiated with radiation is in the range of 0.5 to 50%. 11. The molded product according to claim 5, which is a film or a sheet.