JPH05305701A - Container excellent in boil resistance and its package - Google Patents

Abstract

PURPOSE:To improve the gas-barrier and boil resistant properties of a container by a method wherein an ethylene-vinylester copolymer saponified product A layer containing ethylene in an amount of at least a specific percentage and the vinylester component having a saponification rate of at least a specific percentage and a thermoplastic resin B layer are laminated together with a polyester adhesive agent and the A layer is formed as the outer layer and is substantially nonoriented. CONSTITUTION:An ethylene-vinylester copolymer saponification product layer A containing ethylene in an amount of 20-65mol.% and the vinylester component having a saponification rate of at least 90% and a thermoplastic layer B for use in maintaining the strength of a container are laminated together via a polyester adhesive agent. The laminate thus obtained is thermoformed into the container by arranging the ethylene-vinylester copolymer saponification product layer A to form the outer layer of the container and become substantially nonoriented. In order to form the substantially nonoriented layer A, the container is subjected to the thermoforming such as vacuum forming, vacuum pressure forming and plug-assist vacuum pressure forming with the surface temp. of the layer A kept slightly higher than fusing point.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-layer container having excellent gas barrier properties and boil resistance.

[0002]

2. Description of the Related Art Conventionally, thermoformed containers in which a saponified ethylene-vinyl ester copolymer (hereinafter abbreviated as EVOH) layer is an intermediate layer and both outer layers are polypropylene are used for various purposes. However, since EVOH absorbs moisture during boil treatment, the gas barrier property after boil treatment is inferior to that before boil treatment, and whitening of the EVOH layer has been a problem. It has been proposed to dispose the EVOH layer more than the outer layer in order to recover the gas barrier property quickly after boil treatment, but it has no effect on whitening. Regarding the delamination of the EVOH layer and the thermoplastic resin layer generated after the boil treatment by the dry laminating method, the coextrusion method is used to improve the adhesive force. However, although the co-extrusion method is suitable for small-quantity large-volume production, no solution has been found in the recent trend of the dry laminating method suitable for multi-brand small-quantity production. Further, when the EVOH film is used as the outer layer, there are problems such as streaking, blocking, and whitening.

Japanese Unexamined Patent Publication (Kokai) No. 2-92541 discloses a container for food packaging in which a multilayer structure of EVOH and polypropylene having a specific melt drawing tension can be retort sterilized and has no thickness unevenness or cracks during thermoforming. There is. However, this publication does not describe the delamination of the EVOH layer and the thermoplastic resin layer generated after the boil treatment, and the description of the laminate obtained through the polyester adhesive.

Japanese Examined Patent Publication No. 59-33113 describes a container which is laminated with an unsaturated carboxylic acid-modified thermoplastic resin and is excellent in impact peeling resistance. However, the publication relates to a coextrusion method, and also EVOH
The layer is an intermediate layer, and there is no description about a laminate obtained through a polyester adhesive.

Further, JP-A-59-136254, JP-A-60-105539, and JP-A-63-2.
Japanese Patent No. 96941 describes laminating an EVOH layer and a polyester layer via a polyester adhesive, but using the EVOH layer as an outer layer, and further EVO
There is no mention of the H layer being substantially unoriented. Further, in the container in which the EVOH layer is oriented as described here, the appearance is poor as will be apparent from Comparative Examples 1 and 2 described later.

[0006]

As described above, there is no delamination of the EVOH layer and the thermoplastic resin layer during boil treatment, there is no problem of appearance defect due to streaking, blocking, whitening, etc. of the EVOH layer, and the surface There are not enough thermoformed containers with good gloss, and it has been desired for many years to develop a container that has such characteristics and is suitable for small lot production of many brands.

The present invention was devised in order to solve the above-mentioned drawbacks of the prior art. Even though the EVOH layer obtained through the polyester adhesive is the outer layer laminate, the EVOH layer And there is no delamination of the thermoplastic resin layer,
It is an object of the present invention to obtain a container free from problems such as poor appearance due to occurrence of streaks in the EVOH layer, blocking, and whitening.

[0008]

Means for Solving the Problems The present inventor has conducted earnest research based on the recognition of the above problems, and as a result, found that the ethylene content was 20%.
To 65 mol% and a vinyl ester component having a saponification degree of 90 mol% or more, and an EVOH (A) layer and a thermoplastic resin (B) layer formed from a laminate obtained through a polyester adhesive, the (A) layer Is an outer layer (a thin layer such as a protective layer or a printing layer may be further provided on the outside of the (A) layer), and the container in which the EVOH layer is substantially non-oriented is EV
The inventors have found that there are no problems such as poor appearance, blocking, and whitening due to the occurrence of streaks in the OH layer, and that there is no delamination between the EVOH layer and the thermoplastic resin layer and that the surface gloss is good, and the present invention has been completed.

The present invention will be described in more detail below. In the present invention, EVOH is known as ethylene and vinyl ester using a polymerization initiator such as benzoyl peroxide or azobisisobutyronitrile under pressure in a solvent such as methanol, t-butanol or dimethyl sulfoxide. It is obtained by polymerizing by a method and then saponified with an acid or alkali catalyst. As the fatty acid vinyl ester,
Examples include vinyl acetate, propionate vinyl, versatic acid vinyl ester, pivalic acid vinyl ester, etc. Aromatic carboxylic acid vinyl ester, etc. can be used, but vinyl acetate is a gas barrier and gas barrier property. From this point, vinyl pivalate is preferable. The ethylene content of EVOH is 20-6
5 mol%, preferably 25 to 50 mol%, and the degree of saponification of the vinyl ester component is 90 mol% or more, preferably 95 mol% or more. When the ethylene content is less than 20 mol%, the blocking prevention property during boiling is lowered, and when it exceeds 65 mol%, sufficient gas barrier properties cannot be obtained. On the other hand, when the saponification degree is less than 90 mol%, not only the gas barrier property at high humidity is deteriorated but also the thermal stability of EVOH is deteriorated, and gel is apt to be generated on the obtained film surface.

Further, EVOH has a smaller amount of propylene, isobutene, 4-methylpentene-1, hexene,
Α-olefins such as octene, unsaturated carboxylic acids such as itaconic acid, methacrylic acid, acrylic acid, maleic acid, salts thereof, partial or complete esters thereof, nitriles thereof, amides thereof, anhydrides thereof, vinyltrimethoxysilane, etc. It does not matter even if it contains a copolymerization component such as a vinylsilane compound, unsaturated sulfonic acid, its salt, alkylthiols, N-vinylpyrrolidone.

Furthermore, EVOH may be a mixture of two or more kinds of EVOH having different ethylene contents,
Also, two or more types of EVOH with different degrees of polymerization and saponification
May be a mixture of. Further, the ethylene content and the degree of polymerization or the degree of saponification may be different.

[0012] Further, EVOH contains, within a range that does not impair the present invention, an antioxidant, a colorant, an ultraviolet absorber, a slip agent, an antistatic agent, a plasticizer, a cross-linking agent such as boric acid, an inorganic filler, and an inorganic drying agent. Various additives such as agents and various resins such as polyamide, polyolefin, and super absorbent resin may be blended.

In the present invention, the EVOH (A) layer laminated via the polyester adhesive may be a plurality of layers of two or more kinds of EVOH having different ethylene contents,
Each EVOH layer may be a mixture of the above. In the EVOH (A) layer which is a plurality of layers, it is desirable that all layers are non-oriented, but all layers or specific layers may be oriented layers (for example, uniaxially or biaxially oriented layers).
The surface of the EVOH (A) layer may be cross-linked with various aldehydes such as boric acid and formalin.

The thickness of the EVOH (A) layer is not particularly limited, but 3 to 200 μm is preferable in the flange portion which is heat-sealed due to the barrier property of the container and the price of the container.
More preferably, it is 5 to 100 μm.

In the present invention, the polyester adhesive is a two-component curing type solution type or solventless type adhesive whose main component is polyester polyol or polyurethane polyol and curing agent is polyisocyanate.

As the polyol used as the main component polyester polyol or polyurethane polyol,
Ethylene glycol, trimethylene glycol, 1,4
-Butanediol, 1,6-hexanediol, 1,9
-Nonanediol, 1,10-decanediol, 1,1
Linear diols such as 2-dodecanediol, propylene glycol, 2-methyl-1,3-propanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol,
Branched diols such as 1,4-cyclohexanedimethanol, phenols such as bisphenol A, and epoxy adducts such as ethylene oxide adducts of bisphenol A 1
The main component is one or a mixture of two or more, but ether diols such as diethylene glycol and triethylene glycol, and polyols such as trimethylolpropane, glycerin, and pentaerythritol can be used in arbitrary amounts as minor components.

As the polyisocyanate used in the main component polyester polyol or polyurethane polyol, 4,4'-diphenylmethane diisocyanate, p-phenylene diisocyanate, toluylene diisocyanate, 1,5-naphthylene diisocyanate,
The main component is one or a mixture of two or more of xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, etc., but the hydroxyl groups of polyols such as trimethylolpropane, glycerin and pentaerythritol are All toluylene diisocyanate,
It is also possible to use a compound urethanized with xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate or the like as a small amount component in an arbitrary amount. Furthermore, a compound that is made polyfunctional by a condensation reaction of a diisocyanate compound and water, a compound that is trimerized by a thermal reaction of diisocyanate, and the like can also be used.

Examples of the polycarboxylic acid used in the main component polyester polyol include aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid and dodecanedioic acid, terephthalic acid,
Isophthalic acid, 1,5-naphthalene dicarboxylic acid,
The main component is one or a mixture of two or more aromatic dicarboxylic acids such as 2,5-naphthalene dicarboxylic acid and 2,6-naphthalene dicarboxylic acid, and polyaniline compounds such as anicot acid, pyromellitic acid and trimellitic acid. It is also possible to use any amount of carboxylic acid as a minor component. Further, lower fatty acid esters of these carboxylic acids such as methyl, ethyl, propyl and butyl can also be used.

The hydroxycarboxylic acid used in the main component polyester polyol is one or a mixture of two or more hydroxycarboxylic acids such as parahydroxybenzoic acid, δ-valerolactone, ε-caprolactone, lactic acid, tartaric acid and ascorbic acid. Can also be used.

There is no particular limitation on the method for producing the main component polyester polyol, and known means for polyester polymerization can be applied. For example, the above diol and dicarboxylic acid monomer or lower fatty acid ester thereof alone or in a mixture are charged in a desired composition, and esterification and / or transesterification reaction is carried out at 150 to 250 ° C. in the presence of an esterification and / or transesterification catalyst, The reaction intermediate thus obtained was further subjected to high vacuum at 200
It can be produced by polymerizing at ~ 300 ° C. The average molecular weight is not particularly limited, but is usually 500 to 50.
000, preferably 900 to 20,000.

There is no particular limitation on the method for producing the main component polyurethane polyol, and known means for polyurethane polymerization can be applied. That is, by adding or reacting the mixture of the polyisocyanate and the polyol and / or the polyester polyol at the same time or sequentially, the ratio of the isocyanate group to the active hydrogen atom (hydroxyl group and amino group) is 1 or less. can get. At this time, as chain extenders, ethylene glycol, 1,4-butanediol, 1,6-hexanediol, xylylene glycol, 3-methyl-1,5-pentanediol, bishydroxyethoxybenzene, neopentyl glycol, 1 , 9-nonanediol, isophoronediamine, hydrazine, dihydrazine, trimethylolpropane, glycerin and the like may be used. The above reaction may be carried out in the presence of an organic solvent inert to the isocyanate group. If desired, amines such as triethylamine, triethylenediamine, morpholine, diazabicycloundecene and salts thereof, metal salts such as dibutyltin dilaurate, trimethyltin hydroxide, stannic chloride, potassium oleate and stannas oleate. You may use the urethane formation catalyst of. Among them, amines such as diazabicycloundecene and salts thereof and dibutyltin dilaurate are contained in an amount of 0.5 to 5000 ppm, preferably 1 to 500 pp.
m may be used. The average molecular weight is not particularly limited, but is usually 500 to 100,000 and 800 to 70.
000 is preferred.

As the polyisocyanate of the curing agent, a compound having three or more isocyanate groups in the molecule, for example, all the hydroxyl groups of polyols such as trimertylolpropane, glycerin, pentaerythritol, and polypropylene glycol adducts of glycerin are toluylened. Isocyanate, xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-diphenylmethane diisocyanate, p
-Phenylene diisocyanate, 1,5-naphthylene diisocyanate, compounds urethanized with 4,4'-dicyclohexylmethane diisocyanate, etc., crude MDI, and further compounds polyfunctionalized by condensation reaction of diisocyanate compounds and water, Examples thereof include compounds trimerized by thermal reaction of diisocyanate. A mixture of the above diisocyanate and a compound having 3 or more isocyanate groups in the molecule may be used.

The mixing ratio of the main agent and the curing agent is not particularly limited, and 0.5 to 60 parts by weight of the curing agent per 100 parts by weight of the main agent,
It is preferably 1 to 30 parts by weight.

In the present invention, the thickness of the polyester adhesive layer is not particularly limited, but is preferably 0.5 to 20 μm, and more preferably 1 to 10 μm in the heat-sealed flange portion.

In the present invention, the thermoplastic resin (B) is used for maintaining the strength of the container, and examples of the resin (B) include ethylene homopolymers such as low density polyethylene, medium density polyethylene and high density polyethylene, and linear polymers. Low density polyethylene, ethylene copolymer such as ethylene-vinyl acetate copolymer, propylene homopolymer, propylene copolymer, polyolefin such as polymethylpentene, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyester such as aromatic polyester, poly ε Examples thereof include polyamides such as caprolactam, polyhexamethylene adipamide, and polymethaxylylene adipamide, syndiotactic polystyrene, and polycarbonate, which may be used alone or 2
You may blend and use a thermoplastic resin of 1 or more types. Further, these thermoplastic resins include antioxidants, colorants, ultraviolet absorbers, slip agents, antistatic agents, plasticizers, cross-linking agents, inorganic fillers, inorganic desiccants, as long as they do not hinder the present invention.
You may mix | blend various additives, such as a tackifier, and various thermoplastic resins.

In the present invention, the thermoplastic resin (B) layer may be a multi-layer. The thickness of the thermoplastic resin (B) layer is not particularly limited, but the flange portion to be heat-sealed is preferably 40 to 4000 μm, more preferably 60 to 2000 μm, depending on the strength of the container and the price of the container.

In the present invention, a thermoplastic resin (C) may be further laminated on the innermost layer in order to impart easy peeling property and low temperature heat sealing property of the container. Examples of the thermoplastic resin (C) that imparts easy peelability and / or low temperature heat sealability include polybutene-1, polypropylene, polyethylene, polystyrene, polyester, polyamide, modified partially saponified ethylene-vinyl acetate copolymer and the like. Therefore, they may be used alone or as a blend of two or more thermoplastic resins. However, the thermoplastic resin (B) and the thermoplastic resin (C) are not the same resin at the same time. In addition, these plastics include antioxidants, colorants, ultraviolet absorbers, slip agents, antistatic agents, plasticizers, crosslinking agents, inorganic fillers, inorganic desiccants, tackifiers, etc. within the range that does not impair the present invention. Various additives and various thermoplastic resins may be mixed. Furthermore, the thermoplastic resin (C) layer may be a multilayer.

As the polybutene-1 used in the thermoplastic resin (C) layer, a homopolymer of butene-1 and a copolymer containing butene-1 as a main component with ethylene, propylene, styrene, etc., Examples thereof include those graft-modified with a carboxylic acid such as maleic anhydride.

The polypropylene used in the thermoplastic resin (C) layer is a homopolymer of propylene and ethylene, butene-1,5 containing propylene as a main component.
-Ethylidene-2-norbornene, 5-methylene-2-
Examples thereof include copolymers with norbornene, 1,4-hexadiene, styrene and the like, and those graft-modified with a carboxylic acid such as maleic anhydride.

Examples of polyethylene used in the thermoplastic resin (C) layer include high-density polyethylene, which is a homopolymer of ethylene, medium-density polyethylene, low-density polyethylene, and propylene containing ethylene as a main component.
Butene-1,4-methylpentene-1,1-hexene,
1-octene, 5-ethylidene-2-norbornene, 5
-Methylene-2-norbornene, vinyl acetate, butyl acetate, methyl acrylate, ethyl acrylate, acrylic acid, methyl methacrylate, ethyl methacrylate, methacrylic acid, glycidyl methacrylate, copolymers with styrene and the like can be mentioned. Among the above copolymers, the copolymer with acrylic acid or methacrylic acid may be crosslinked with sodium, zinc, aluminum or the like, and the copolymer with vinyl acetate, butyl acetate or the like may be used as an ester component. Some or all may be saponified. The polyethylene may be graft-modified with a carboxylic acid such as maleic anhydride.

As the polystyrene used in the thermoplastic resin (C) layer, homopolymers of styrene and copolymers containing styrene as a main component with ethylene, propylene, butene-1, butadiene, acrylonitrile, methyl acrylate, etc. A polymer may be used, and a rubber component may be blended.

Further, as the polyester used for the thermoplastic resin (C) layer, ethylene glycol, diethylene glycol, trimethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, 4 , 4
′ -Dihydroxydiphenyl-2,2-propane, glycerin, pentaerythritol and other polyhydric alcohol components, and parahydroxybenzoic acid, ε-caprolactone, δ
-Hydroxycarboxylic acid components such as valerolactone, 3-hydroxybutyric acid, 2-hydroxypropionic acid, tartaric acid and lactic acid, and terephthalic acid, isophthalic acid, various naphthalene dicarboxylic acids, azelaic acid, sebacic acid, pimelic acid, adipic acid, glutaric acid Examples thereof include polycarboxylic acids such as acids and succinic acids, and polyesters obtained from the ester component thereof as raw materials.

Further, as the polyamide used in the thermoplastic resin (C) layer, diamine components such as hexamethylenediamine, piperazine, tetramethylenediamine, ethylenediamine and metaxylylenediamine, and δ-
Aminocarboxylic acid components such as valerolactam, ε-caprolactam, ω-laurolactam, ω-aminoundecanoic acid, ω-aminododecanoic acid, and various naphthalene dicarboxylic acids, terephthalic acid, isophthalic acid, azelaic acid, sebacic acid, pimelic acid. Examples thereof include polyamides obtained from polyvalent carboxylic acid components such as adipic acid, glutaric acid and succinic acid as raw materials.

In the present invention, the thickness of the thermoplastic resin (C) layer is not particularly limited, but it is preferably 0.5 to 100 μm, more preferably 1 to 60 μm in the heat sealed flange portion of the container. ..

In the present invention, the method for laminating the thermoplastic resin (B) layer and the thermoplastic resin (C) layer is not particularly limited, and the thermoplastic resin (B) and the thermoplastic resin (C) are laminated by a coextrusion method. The thermoplastic resin (B) layer may be laminated with the thermoplastic resin (C) by an extrusion laminating method, or the thermoplastic resin (B) layer and the thermoplastic resin (C) layer may be dry laminated. Method or hot melt laminating method may be used for lamination. When the adhesive force is insufficient in the coextrusion method or the extrusion laminating method, an adhesive resin or an anchor coating agent may be used. Further, the EVOH (A) layer and the thermoplastic resin (B) layer may be laminated and then the thermoplastic resin (C) layer may be laminated, or the thermoplastic resin (C) layer and the thermoplastic resin (B) layer may be laminated. After that, an EVOH (A) layer may be laminated.

In the present invention, the EVOH (A) layer serves as the outer layer of the laminate thus obtained and the (A) layer is used as the outer layer.
The container must be thermoformed so that the layers are substantially non-oriented. When the EVOH (A) layer is molded so as to be the inner layer, the barrier properties of the container after filling the contents, heat sealing the lid, and boiling are slow to recover, and cannot be put to practical use. The term "outer layer (A)" means that it is the outermost layer, but within the range where the object of the present invention is not alienated (A).
It is free to further provide a thin layer such as a protective layer or a printing layer on the outside of the layer.

In the present invention, the layers (B) and (C) of the container may be oriented or non-oriented,
It is desirable to be non-oriented. However, the EVO of the container
Since the orientation of the H (A) layer causes delamination and streaking during the boil treatment, it is important that the EVOH (A) layer is substantially non-oriented. In order to make the EVOH (A) layer substantially non-oriented, the temperature of the surface of the EVOH (A) layer is 5 ° C. higher than the melting point, preferably 10 ° C. higher than the melting point, more preferably 15 ° C. higher than the melting point. Thermoforming at temperature is important. As the thermoforming method, vacuum forming, vacuum pressure forming, and plug assist vacuum pressure forming can be adopted. It is desirable to heat the sheet from the EVOH (A) layer side from the viewpoint of preventing the drawdown of the sheet, but it is not limited to this. Also EVOH
In order to increase the crystallinity of the layer (A), it is desirable to hold it for 2 seconds or longer, preferably 5 seconds or longer in the mold after molding. The melting point of the EVOH (A) layer is a main endothermic peak temperature obtained by measurement using a SSC5200 series RDSC220 manufactured by Seiko Denshi Kogyo Co., Ltd. under a nitrogen stream at a temperature rising rate of 10 ° C./min. The main endothermic peak temperature when the EVOH (A) layer is a blend and / or a multilayer body means the endothermic peak temperature of EVOH occupying 70% by weight or more of the whole, and when any EVOH is less than 70% by weight. The higher endothermic peak temperature of EVOH occupying 25% by weight or more, and the highest endothermic peak temperature when any EVOH is less than 25% by weight. The EVOH (A) layer being substantially non-oriented means that the retardation when observed with a polarization microscope is 70 nm or less,
This means that at least the EVOH (A) layer in the body portion of the container is non-oriented, but when the EVOH (A) layer is a plurality of layers, at least one of them is substantially non-oriented and The layer may be an alignment layer, but it is preferable that all of the plurality of layers are non-alignment.

The container thus obtained employs a polyester adhesive, and although the EVOH layer is used as the outer layer, the delamination of the EVOH layer and the thermoplastic resin (B) layer during the boil treatment is performed. It has no appearance defects due to streaks in the EVOH layer, blocking, whitening, etc. and has a good surface gloss, and has excellent gas barrier properties, such as amniotic fluid, pudding, jelly, honey beans, fruits, etc. Confectionery, mainspring, warabi, Suan, pickles such as rape, processed foods such as sausage and kamaboko, corn soup, meat sauce,
It can be suitably applied to various foods such as cooked rice, meat and potatoes, and side dishes such as boiled beans.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. All parts and% are based on weight unless otherwise specified.

[0040]

【Example】

Example 1 An 800 μm-thick unstretched polypropylene sheet (“Oparay N-410” manufactured by Idemitsu Petrochemical Co., Ltd.) (B) layer was subjected to corona treatment, and isophthalic acid:
Terephthalic acid: sebacic acid: adipic acid = 4: 1: 4:
1 (molar ratio), ethylene glycol: diethylene glycol = 9: 1 (molar ratio) as a main component, an ethyl acetate solution of a polyester polyol, and trimethylolpropane: meta-xylylene diisocyanate = 1: 3 (molar ratio) triisocyanate As the curing agent, the ethyl acetate solution was used as the curing agent, and 20 parts by weight of the curing agent was added to 100 parts by weight of the main ingredient, 4 g / m ↑ 2 of the solid content was applied, the solvent was evaporated, and then the ethylene content was 47 mol% and the vinyl ester component Saponification degree of 99.5 mol%, melting point 160 ° C, thickness 50μ
m non-stretched EVOH film (B) layer was laminated at a speed of 30 m / min to obtain a laminated sheet. The laminated sheet was vacuum-formed at a sheet surface temperature of 170 ° C. to obtain a round container having a drawing ratio of 0.4 and an internal volume of 140 ml (ml).

As a film used for a lid for heat-sealing the container, a polyvinylidene chloride-coated biaxially stretched polyethylene terephthalate film (“Emblet DC KPT” manufactured by Unitika Ltd.) having a thickness of 12 μm and a thickness of 60 μm are used. An unstretched polypropylene film (“Tocello RXC-7” manufactured by Tokyo Cellophane Paper Co., Ltd.) and a polyester-based adhesive (“A-3 manufactured by Takeda Pharmaceutical Co., Ltd.”)
85 / A-50 ") and 3 g / m ↑ 2 as solid content.
Used to obtain a laminated film.

140 ml of water was placed in the container, the laminated film was heat-sealed, and the bottoms of the container were brought into contact with each other.
I boiled for 0 minutes. No change in appearance such as delamination or blocking between the containers was observed, and good boiling resistance was obtained.
One day after boiling, the gas barrier property of the container was measured at a temperature of 20 ° C. and a humidity of 85%, and it was 0.025 ml (ml) / cup day atm (measured by OX-TRAN 10 / 50A manufactured by Modern Control Co., Ltd.). And was good.

Comparative Example 1 A container and a laminated film were obtained under the same conditions as in Example 1 except that the sheet surface temperature was changed to 150 ° C.

140 ml of water was put in the container, the laminated film was heat-sealed, and the bottoms of the container were brought into contact with each other.
Although boiled for 0 minutes, streaks were observed in the EVOH layer and the appearance was poor.

Example 2 An unstretched polypropylene sheet having a thickness of 600 μm (“Orphan P- (T)” manufactured by Osaka Jushi Kogyo Co., Ltd.) (B) was coated on the corona-treated surface with isophthalic acid: adipic acid = 1: 1. Three
(Molar ratio), ethylene glycol: butanediol: diethylene glycol = 15: 11: 12 (molar ratio), and isophorone diisocyanate (3 mols per 100 mols of total of dicarboxylic acid and diol) as a main component of ethyl acetate solution of polyurethane polyol , Trimethylolpropane: meta-xylylene diisocyanate: isophorone diisocyanate = 2: 3: 3 (molar ratio) was used as a curing agent, and an ethyl acetate solution of triisocyanate was used as a curing agent. 3 g / m ↑ 2 as the coating solution and after evaporating the solvent, the ethylene content is 32 mol%, the saponification degree of the vinyl ester component is 99.
Unstretched EVO with 5 mol%, melting point 181 ° C, and thickness of 30 μm
The H film (B) layer was laminated at a speed of 50 m / min to obtain a laminated sheet. The laminated sheet was vacuum formed at a sheet surface temperature of 200 ° C. to obtain a round container having a drawing ratio of 0.4 and an internal volume of 140 ml.

As a film used for a lid for heat-sealing the container, a polyvinylidene chloride-coated biaxially stretched nylon film (“Embum DC DCR” manufactured by Unitika Ltd.) having a thickness of 15 μm and a non-stretching film having a thickness of 60 μm Polypropylene film (“Tocello RXC-7” manufactured by Tokyo Cellophane Paper Co., Ltd.) and polyester adhesive (“A-385 / A-50” manufactured by Takeda Pharmaceutical Co., Ltd.) were used as solid content of 3 g. / M ↑ 2 was used to obtain a laminated film.

140 ml of water was put into the container, the laminated film was heat-sealed, and the bottoms of the container were brought into contact with each other.
I boiled for 0 minutes. No change in appearance such as delamination or blocking between the containers was observed, and good boiling resistance was obtained.
One day after boil, the gas barrier property of the container was measured at a temperature of 20 ° C. and a humidity of 85%, and it was a good value of 0.039 ml / cup · day · atm.

Comparative Example 2 A container and a laminated film were obtained under the same conditions as in Example 2 except that the sheet surface temperature was changed to 175 ° C.

140 ml of water was put into the container, the laminated film was heat-sealed, and the bottoms of the container were brought into contact with each other.
Although boiled for 0 minutes, the EVOH layer was whitened and the containers were blocked, and the boil resistance was poor.

Example 3 Polypropylene homopolymer (MA manufactured by Mitsubishi Petrochemical Co., Ltd.)
-8) 40% by weight, 45% by weight of polypropylene block copolymer (8100J manufactured by Mitsubishi Kasei Co., Ltd.), and low-density polyethylene (HE-30 manufactured by Mitsubishi Yuka Co., Ltd.) 1
A propylene-styrene copolymer (styrene content 30% by weight) as an easy peeling resin layer was applied to an 800 μm sheet made of a composition of 5% by weight at 240 ° C. and a thickness of 20 μm.
An extruded sheet was obtained at m.

As a film used for a lid for heat-sealing the container, a polyvinylidene chloride-coated biaxially stretched nylon film (“Embum DC DCR” manufactured by Unitika Ltd.) having a thickness of 15 μm and an unstretched film having a thickness of 60 μm Polypropylene film (“Tocello RXC-7” manufactured by Tokyo Cellophane Paper Co., Ltd.) and polyester adhesive (“A-385 / A-50” manufactured by Takeda Pharmaceutical Co., Ltd.) were used as solid content of 3 g. / M ↑ 2 was used to obtain a laminated film.

The composition surface of the sheet was corona-treated, and isophthalic acid: adipic acid = 1: 1 (molar ratio), 2-methyl-1,8-nonanediol: 1,9 was applied to the corona-treated surface.
-Nonanediol = 6: 1 (molar ratio) as a main component of an ethyl acetate solution of a polyester polyol, and trimethylolpropane: isophorone diisocyanate = 1: 3
(Mole ratio) Triethylisocyanate in ethyl acetate was used as a curing agent, 16 parts by weight of the curing agent was added to 100 parts by weight of the main agent, 4 g / m ↑ 2 was applied as a solid content, the solvent was evaporated, and ethylene was added. Amount 44 mol%, saponification degree of vinyl ester component 99.5 mol%, melting point 164 ° C., thickness 5
A 0 μm EVOH film (B) layer was laminated at a speed of 30 m / min to obtain a laminated sheet. The laminated sheet was vacuum formed at a sheet surface temperature of 200 ° C. to obtain a round container having a drawing ratio of 0.4 and an internal volume of 140 ml.

140 ml of water was placed in the container, the laminated film was heat-sealed with a lid material, and the bottoms of the container were brought into contact with each other.
Boiled for 30 minutes at 2 ° C. No change in appearance such as delamination or blocking between the containers was observed, and good boiling resistance was obtained. One day after boiling, the gas barrier property of the container was measured at a temperature of 20 ° C. and a humidity of 85%.
It was good as / cup · day · atm.

Comparative Example 3 In Example 3, the main component was an ethyl acetate solution of a polyether polyol consisting of polypropylene glycol: toluylene diisocyanate = 1: 1 (molar ratio), and trimethylolpropane: toluylene diisocyanate =
An ethyl acetate solution of triisocyanate of 1: 3 (molar ratio) was used as a curing agent, and 100 parts by weight of the main agent was added to the curing agent.
A container and a laminated film were obtained under the same conditions as in Example 3 except that the weight part was changed.

140 ml of water was put in the container, the laminated film was heat-sealed with a lid material, and the bottoms of the container were brought into contact with each other.
It was boiled at 30 ° C. for 30 minutes. Delamination occurred and the boiling resistance was poor.

[0056]

[Table 1]

[0057]

[Table 2]

[0058]

As described above, the thermoformed container of the present invention has no delamination between the EVOH layer and the thermoplastic resin layer during boil treatment, and has no problems such as poor appearance, blocking, and whitening due to the occurrence of streaks in the EVOH layer. Moreover, it has good surface gloss and excellent gas barrier properties, and can be suitably applied to various foods.

Claims (3)

[Claims] 1. An ethylene having an ethylene content of 20 to 65 mol% and a saponification degree of a vinyl ester component of 90 mol% or more.
It comprises a laminate obtained by saponifying a vinyl ester copolymer (A) layer and a thermoplastic resin (B) layer via a polyester-based adhesive, the (A) layer being an outer layer, and being substantially non-existent. A container that is oriented. 2. The container according to claim 1, which has an easy peel layer or a heat seal layer as an inner layer. 3. A packaging body in which the container according to claim 1 or 2 is filled with contents, the lid is heat-sealed, and then sterilized in hot water at 70 to 100 ° C. for 20 minutes or more.