JPH10291285A - Laminated material and package using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated material effective for use in a food packaging field by not only suppressing a decrease in a mechanical strength but also particularly suppressing generation of decomposing odor for use in a sealant film of the material with a polypropylene film having small deterioration against ionizing radiation to cure an adhesive and a package using it in the laminated material laminated by using the adhesive made of ionizing radiation curable resin and the package shaped into a desired shape by using the material. SOLUTION: In the laminated material 10 obtained by laminating a base material film 1 made of at least one type or more of film and a sealant film 3 via ionizing radiation curable adhesive 2, the film 3 is formed of a polypropylene having a syndiotactic structure or a mixture of the polypropylene having the syndiotactic structure and a polypropylene having an isotactic structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated material laminated using an adhesive made of an ionizing radiation-curable resin and a package molded using the laminated material. More specifically, by using a film that is less degraded by ionizing radiation irradiated to cure the adhesive for the film constituting the laminated material, generation of decomposition odors is particularly suppressed, and unusual odors in the food packaging field and the like are used. TECHNICAL FIELD The present invention relates to a laminated material suitable for a field in which strict demands are made for the mixing of lacquer and a package using the same.

[0002]

2. Description of the Related Art In recent years, with the spread of various types of packaging such as food packaging, pharmaceutical packaging, cosmetic packaging, etc., the performance required for packaging materials has been diversified. Therefore, in order to satisfy these demands, one kind of material is necessary and sufficient effect cannot be obtained, and therefore, a laminated material obtained by laminating two or more kinds of materials is widely used depending on the application and purpose. I have.

When this laminated material is used for packaging,
In many cases, it is used as a bag-like package or a lid material for a packaging container, and therefore, it is necessary to have heat sealability. Therefore, a laminated material having a structure in which a sealant film having heat sealability is laminated on a base film for imparting mechanical strength or barrier properties according to the application is generally used.

[0004] The sealant film has a low density,
Inexpensive and heat-sealable polyolefin-based synthetic resin films such as medium-density, high-density polyethylene films, polypropylene films, copolymer films of ethylene and α-olefin, and ethylene-vinyl acetate copolymer films are preferably used. . Among them, polypropylene film is excellent in oil resistance, heat resistance, moisture resistance, waterproofness, scratch resistance, transparency, surface gloss, moldability, etc., so that food packaging such as snack confectionery, dried food, boiled retort food etc. It is used for materials and packaging materials for medical instruments.

At present, this polypropylene film is a multi-site catalyst exhibiting heterogeneous active sites, such as titanium tetrachloride supported on magnesium chloride, titanium trichloride reduced by organoaluminum, or titanium trichloride reduced by metal aluminum.
It is manufactured using a polypropylene resin having an isotactic structure polymerized by a so-called Ziegler-Natta catalyst. Here, the isotactic structure means a structure in which a methyl group which is a side chain is located in the same direction with respect to a polypropylene main chain.

[0006] The plastic film, paper, metal foil, etc. constituting the laminated material are generally compounded by dry lamination, non-solvent lamination, or wet lamination through an adhesive. In addition, a polyurethane-based adhesive composed of two components, an isocyanate compound and a polyol compound, is used. Polyurethane-based adhesives have the characteristic of having excellent performance for many physical properties required for laminated materials, but usually take 1 to 7 days in a constant temperature room at 35 to 60 ° C because of the long time required for curing. Curing of the adhesive is promoted. Therefore, there has been a problem in production efficiency that the next step (slitter, bag making, etc.) cannot be started until after curing.

In response to this problem, the development of an ionizing radiation-curable adhesive having a functional group reactive with ionizing radiation in the composition and having the property of being instantaneously cured by the energy of radiation has recently been omitted due to the omission of the curing step. In order to improve productivity, a method of laminating a plastic film, a metal foil, paper, or the like using the ionizing radiation-curable adhesive has been tried in the field of packaging, the field of building materials, and the like. On the other hand,
The lamination method using an ionizing radiation-curable adhesive has a significant effect on plastic films due to the high energy of the electron beam irradiated to cure the adhesive. Practical problems such as extremely brittleness, generation of decomposed odor, and coloring of the film due to a decrease in mechanical strength derived from the above have been cited.

Various proposals have been made to solve the decomposition and deterioration of plastics caused by irradiation with ionizing radiation. For example, according to Japanese Patent Application Laid-Open No. 6-106626,
A method of winding a laminated body laminated with an electron beam-curable adhesive on a winding roll in an inert gas atmosphere is exemplified. However, according to this method, since the laminated body must be placed in an inert gas atmosphere from irradiating the laminated body with an electron beam to winding it on a take-up roll, large-scale equipment is required.

On the other hand, as shown in JP-A-57-179234, JP-A-58-49737, and JP-A-58-103541, hindered amine compounds and phenol compounds or phosphites specific to polyolefin resins are disclosed. There has been disclosed a radiation-resistant resin composition in which a system compound or the like is added to prevent decomposition and deterioration of the resin due to radiation irradiation. JP-A-6-106626 also discloses a method of adding various stabilizers to a laminated film. Further, Japanese Patent Application Laid-Open No. Sho 60-55005 discloses a resin composition which uses a random ethylene-propylene copolymer resin having a specific ethylene content to suppress deterioration of physical properties due to radiation irradiation in the same manner as described above.

[0010] However, as mentioned above,
When the above-mentioned treatment is performed on the isotactic polypropylene polymerized by the used Ziegler-Natta catalyst, problems of mechanical properties such as tensile elongation and impact strength and coloring of the film are improved. However, the resin composition proposed above was mainly used for radiation sterilization of medical containers, and its odor has not been studied.In particular, foods that dislike the adsorption of off-flavor components to the contents When used for packaging purposes, satisfactory performance has not been obtained.

[0011]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems, and it is an object of the present invention to provide a laminated material laminated using an adhesive made of ionizing radiation-curable resin and a desired material using the laminated material. By using a polypropylene film, which is less degraded by ionizing radiation irradiated for curing the adhesive, in the sealant film of the laminated material in the package formed into the shape of the above, only the reduction in mechanical strength is suppressed. In addition, it is an object of the present invention to provide a laminated material effective for use in the food packaging field and the like and a package using the same, in particular, by suppressing generation of decomposition odor.

[0012]

That is, the present invention relates to a laminated material obtained by laminating a base film comprising at least one or more films and a sealant film via an ionizing radiation-curable adhesive. Is a laminated material comprising a polypropylene having a syndiotactic structure or a mixture of a polypropylene having a syndiotactic structure and a polypropylene having an isotactic structure.

In the above-mentioned mixture of the polypropylene having a syndiotactic structure and the polypropylene having an isotactic structure, the mixture weight ratio is 30.
/ 70 to 99/1, preferably 70/30 to 99/1.

The polypropylene having the syndiotactic structure has a syndiotacticity of 0.1.
5 or more, preferably 0.7 or more.

[0015] Further, the laminated material is characterized in that the polypropylene having the syndiotactic structure is a copolymer with another α-olefin.

Further, the present invention is characterized in that a base material comprising at least one or more films and a sealant film are formed into a desired shape by using a laminated material which is laminated via an ionizing radiation-curable adhesive. The sealant film is made of polypropylene having a syndiotactic structure.

Further, the mixing weight ratio of the polypropylene having the syndiotactic structure and the polypropylene having the isotactic structure is 30/70 to 99/1, preferably 70/30 to 99/1. Package.

The polypropylene having the syndiotactic structure has a syndiotacticity of 0.1.
5 or more, preferably 0.7 or more.

Further, the present invention provides a package wherein the polypropylene having the syndiotactic structure is a copolymer with another α-olefin.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments. FIG. 1 is a sectional view showing one embodiment of the laminated material of the present invention. The laminated material 10 has a configuration in which at least one or more base films 1 and a sealant film 3 are laminated via an ionizing radiation-curable adhesive 2.

The substrate film 1 used in the present invention is appropriately selected depending on the use of the final packaging form, but forms a structural support for maintaining the physical strength of the laminated material 1. Single-layer or laminated films can be used. For example, a biaxially oriented polypropylene film, a biaxially oriented polyester film, a biaxially oriented nylon film, a polyvinylidene chloride coated film of the above films, a cellophane film, a monolayer body of a resin film such as an ethylene-vinyl alcohol copolymer film or A laminated body, or a vapor-deposited film obtained by performing a vapor-deposition process on the surface of the resin film,
Further, a laminated film of the resin film and metal foil, paper, or the like can be used. Also, if necessary,
The base film may be printed.

Examples of the vapor-deposited film include aluminum, gold, silver, biaxially oriented polypropylene film, biaxially oriented polyester film, and biaxially oriented nylon film.
Copper, iron, those formed by vapor deposition of a metal thin film such as tin, or silicon oxide, aluminum oxide, magnesium oxide,
Examples thereof include a thin film formed by vapor deposition of a transparent inorganic oxide such as calcium oxide.Examples of the metal foil include aluminum foil, gold foil, silver foil, copper foil, iron foil, and tin foil. Examples include paper, medium quality paper, pure white roll paper, art paper, various coated papers, and the like. Base film 1
May be in the range of 5 μm to 500 μm, and particularly when an electron beam is used for ionizing radiation, the thickness is preferably about 5 μm to 300 μm from the viewpoint of easy transmission of the electron beam.

The ionizing radiation-curable adhesive 2 used in the present invention is a solventless or solvent-dilutable adhesive made of an ionizing radiation-curable resin. As the electron beam-curable resin, a vinyl functional group such as an acryloyl group, an allyl group, or a vinyl group, which is generally called a photopolymerizable oligomer, is used.
The main component is an oligomer or prepolymer having one to several oligomers or prepolymers having an unsaturated bond that is not a vinyl type, and is polymerized by irradiation with ionizing radiation to produce a polymer. Acrylic and methacrylic resins are mainly used.
Examples include oligomers or prepolymers such as polyester (meth) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate, polyether (meth) acrylate, and melamine (meth) acrylate resins.

Further, for the purpose of improving the adhesive property, an acrylate containing phosphorus or a derivative thereof, an acrylate containing a carboxyl group or a derivative thereof, and the like, and for the purpose of adjusting the viscosity of the adhesive, a photopolymerizable monomer (monomers) are used. Various additives such as functional, bifunctional or polyfunctional acrylates can be added.

The sealant film 3 used in the present invention
For example, a polypropylene film having a syndiotactic structure can be used. Here, the syndiotactic structure refers to a structure in which methyl groups as side chains are alternately located in opposite directions with respect to the polypropylene main chain. This polypropylene having a syndiotactic structure can be produced, for example, by polymerizing with a single-site catalyst having a uniform active site.

As a single site catalyst, for example,
A transition metal compound having an asymmetric ligand (a so-called metallocene-based catalyst) and a cyclic or chain aluminoxane (a cocatalyst), and, if necessary, those supported on a fine particle inorganic compound are used. .

Examples of the transition metal compound having an asymmetric ligand include transition metals selected from Groups IVA to VIB of the periodic table, for example, titanium, zirconium, hafnium and the like, cyclopentadienyl group, indenyl group, fluorenyl. Group and two different groups selected from substituted derivatives such as a methyl group and a tertiary butyl group, and the like, preferably in order to give the two different groups three-dimensional rigidity. , Tertiary isobutyl groups such as alkyl groups, alkylaryl groups, aryl groups, or compounds containing germanium, silicon, oxygen, nitrogen, tin, halogen, sulfur atoms, etc., to form a crosslinked structure by a covalent bond. Can be illustrated.

More specifically, isopropyl (cyclopentadienyl-1-fluorenyl) zirconium dichloride, dimethylsilylene (methylcyclopentadienyl) (2-7-di-tert-butyl-9-fluorenyl) zirconium dimethyl, Isopropyl (cyclopentadienyl-1-fluorenyl) hafnium dichloride, isopropylidene (cyclopentadienyl) (2-7-di-
Tertiary butyl-9-fluorenyl) zirconium dichloride, dimethylsilanediyl-bis (9-fluorenyl)
Zirconium dichloride, 1,6-bis [methylsilyl (indenyl) (cyclopentazinyl) zirconium dichloride] hexane, 2,3-butanediylidenebis (cyclopentadienyl-9-fluorenyl) zirconium dichloride, diphenylmethylene (cyclopentane) Dienyl) fluorenylzirconium dichloride, phenylmethylene (cyclopentadienyl-9-fluorenyl) zirconium dichloride, [methyl (phenyl) methylene] (9-fluorenyl) (cyclopentadienyl) zirconium dichloride, and the like.

The chain or cyclic aluminoxane of the cocatalyst is synthesized by adding water to an alkylaluminum such as trimethylaluminum or triisobutylaluminum, and usually, aluminoxane is used for one of the above transition metal compounds. Used by adding 100 to 10,000 times. Further, examples of the fine particle inorganic compound for supporting the catalyst include silica gel and zeolite. The polymerization method using such a catalyst is not particularly limited, and a known solvent polymerization method, bulk polymerization method, gas phase polymerization method, or the like can be used.

While an example of a catalyst for obtaining a polypropylene having a syndiotactic structure has been described above, even when a catalyst having a structure different from that described above is used, polypropylene having a syndiotactic structure can be obtained when propylene is polymerized. It is not particularly limited as long as it can be performed.

The syndiotactic city of the polypropylene having the syndiotactic structure thus obtained is 0.5 or more, preferably 0.7 or more. If the syndiotacticity is less than 0.5, a decrease in stereoregularity results in an elastomeric polymer,
It is not preferable because various physical properties become insufficient. In addition, the weight average molecular weight and the number average molecular weight (Mw / M
n) is 1.5 to 5, and the melt flow rate (MF)
R) is about 1 to 30.

The polypropylene having the syndiotactic structure includes ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene and 1-octene.
-Nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 3-methyl-1-butene, 4-methyl-1-pentene , 4,4-
It may be a copolymer with an α-olefin having 3 or more carbon atoms such as dimethyl-1 pentene. Also in this case, the syndiotacticity of the obtained polypropylene copolymer having a syndiotactic structure is preferably within the above range.

Further, for the purpose of improving the film forming property and the transparency when the polypropylene having the syndiotactic structure is used alone, the polypropylene having the syndiotactic structure is used to such an extent that the ionizing radiation resistance is not reduced. In contrast, isotactic polypropylene which is polymerized from conventional Ziegler-Natta catalysts (multi-site catalysts) or metallocene catalysts (single-site catalysts), and the isotactic polypropylene and ethylene or 1- Butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1
-Decene, 1-undecene, 1-dodecene, 1-tridecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 3-methyl-1-butene, 4-methyl-1-pentene, 4,4 -Dimethyl-1
A copolymer with an α-olefin having 3 or more carbon atoms such as pentene may be mixed. The mixing ratio is as follows: polypropylene having a syndiotactic structure / polypropylene having an isotactic structure = 30/70 to 99/1, preferably 70/3.
When it is 0 to 99/1, it is excellent in ionizing radiation resistance, and it is possible to significantly suppress generation of odor after irradiation.

If necessary, additional components may be added to the polypropylene having the syndiotactic structure to such an extent that the effects of the present invention are not impaired. Additional components include, for example, antioxidants and ultraviolet absorbers,
Examples include neutralizing agents, antistatic agents, antiblocking agents, lubricants, organic or inorganic fillers, nucleating agents, anti-fogging agents, pigments, foaming agents and the like.

As a method of laminating the base film 1 and the sealant film 3 with the ionizing radiation-curable adhesive 2, a known method can be used. In this case, if necessary, the adhesive 2 is adjusted to an appropriate viscosity by heating or the like, and a gravure roll coating method, a (reverse) roll coating method, an offset gravure coating method, a blade coating method, an air knife coating method, An ionizing radiation curable adhesive 2 is applied to the base film 1 by a coating method such as a kiss roll coating method, a flexographic printing method, or an offset printing method, and a sealant film 3 is attached thereto. To cure the adhesive 2 to obtain a laminated material 10. In the case of the solvent-dilutable ionizing radiation-curable adhesive 2, the adhesive 2 is applied to the base film 1 by the above-described coating method, and then the solvent is evaporated through a solvent drying oven. 3 and a method of curing the adhesive 2 by irradiating ionizing radiation with an ionizing radiation irradiation device.

The bonding of the base film 1 coated with the ionizing radiation-curable adhesive 2 and the sealant film 3 may be performed by a general method, and preferably the wettability of the adhesive 2 with respect to the base film 1 and the sealant film 3. In order to improve the adhesiveness and improve the adhesiveness, the temperature of the pressure roll during bonding is 35 to 85 ° C, and the pressure during pressure bonding is 1 to 10 kg.
/ Cm ² .

The ionizing radiation for promoting the curing of the adhesive includes ultraviolet rays, an electron beam, a neutron beam and the like, and more preferably an electron beam. In the case of electron beam irradiation, the electron beam irradiation device can be any of electron curtain type, high frequency type, dynamitron type, linear type, bandeograph type, resonance transformer type, Cockloft Walton type, insulating core transformer type, scan beam type etc. The electron beam dose is preferably from 10 to 100 kGy from the viewpoint of suppressing the curability of the adhesive and the deterioration of the physical properties of the laminated material. A more preferable dose range is 20 to 50 kGy.

The package of the present invention can be obtained by shaping the laminated material 10 obtained as described above into a desired shape. For example, a bag-like package or a lid material for container packaging can be exemplified. Examples of the bag-like package include a three-sided or four-sided seal bag, a gasket seal (pillow) bag, a gusset bag, a standing bag, a stick package, a strip package, a bag-in-box, a laminate tube, a boiled package, a liquid paper container, and the like. No. Examples of the lid material for container packaging include lid materials for deep drawing packaging containers, injection molding cups, and the like.

The laminating material 10 used for the bag-like package or the lid material for containers and packaging is variously selected according to the required characteristics such as the kind and shape of the contents, the content, the shelf life, the packaging form and the distribution environment conditions. Is done. For example, in the case of snacks such as snacks, rice crackers, instant noodles and moisture-absorbing foods, biaxially stretched polypropylene films (hereinafter referred to as OPP)
Abbreviated) / printing / ionizing radiation curable adhesive (hereinafter ADH)
Abbreviation) / polypropylene film having a syndiotactic structure (hereinafter abbreviated as SPP), glassine paper / printing /
ADH / SPP, polyvinylidene chloride coated biaxially oriented polypropylene film (hereinafter abbreviated as KOP) / printing / A
DH / SPP, moisture-proof cellophane / printing / ADH / SPP, and the like.

For processed oils and fats such as potato chips and fried rice crackers, OPP / print / ADH / aluminum-evaporated biaxially stretched polyester film (hereinafter abbreviated as AlVM-PET)
/ ADH / SPP, KOP / printing / ADH / SPP, silicon oxide deposited biaxially stretched polyester film (hereinafter Si
OVM-PET) / printing / ADH / SPP.

For chilled and frozen foods such as ice confectionery,
OPP / Print / ADH / SPP, KOP / Print / ADH
/ SPP, biaxially stretched polyester film (hereinafter referred to as OP
ET) / printing / ADH / CPP, biaxially stretched nylon film (hereinafter abbreviated as ONY) / ADH / SPP, and the like.

Further, as a standing bag used for a packaging container for a refillable liquid detergent or the like, biaxially stretched nylon film / printing / ADH / SPP, OPET / printing / AD
H / ONY / ADH / SPP and the like.

Further, as the pharmaceutical packaging material, cellophane / printing / ADH / SPP is used, and as the sterilization pharmaceutical packaging material, OPET / printing / ADH / SPP is combined with sterilized paper.

As the bag-in-box, there is a configuration in which SPP / ADH / ONY / ADH / SPP is used for the outer layer bag and SPP is used for the inner layer bag, and two layers are stacked.

As a laminate tube, SP
P / Print / ADH / Aluminum foil / ADH / SPP, SPP
/ Printing / ADH / white polyethylene / ADH / ethylene-vinyl alcohol copolymer film (hereinafter abbreviated as EVOH) / ADH / SPP, SPP / printing / ADH / white polyethylene / acid-modified polyethylene / aluminum foil / ADH /
A material obtained by forming a laminated material having a configuration such as SPP into a cylindrical shape by a high-frequency sealing method may be used.

As a boiler package, ONY /
Print / ADH / SPP, PET / Print / ADH / SP
P, polyvinylidene chloride coated biaxially stretched nylon film (hereinafter abbreviated as KONY) / printing / ADH / SPP.

As the liquid paper container, aluminum foil / A
DH / PET / ADH / SPP, aluminum foil / ADH / S
PP, SiOVM-PET / ADH / SPP, PET /
A laminated material having a configuration such as ADH / SPP is used as an inner layer material, and this is used as an outer layer material having a configuration such as printing / PE / paper and an acid-modified polyethylene resin or a low-density polyethylene resin (hereinafter, LDPE).
And the like, and sandwich-extruded and laminated.

Further, various trays formed by deep drawing include SPP / ADH / KONY / ADH / SPP, SPP
PP / ADH / unstretched nylon film (hereinafter CNY
) / ADH / SPP, aluminum foil / ADH / SPP, and the like.

Further, PET / print /
ADH / SPP, OPP / Print / ADH / SPP, KO
Examples are P / printing / ADH / SPP, PET / printing / ADH / aluminum foil / ADH / SPP, and the like.

<Operation> The method of forming the laminated material 10 using the ionizing radiation-curable adhesive 2 does not require a curing period because the adhesive 2 is instantaneously cured. Although it is a very useful means because it can be performed, there is a drawback that irradiation of ionizing radiation has a bad effect such as generation of decomposition odor and strength deterioration particularly on the plastic film constituting the laminated material. .

Like the laminated material 10 of the present invention, the sealant film 3 constituting the laminated material 10 is made of a single film of polypropylene having a syndiotactic structure,
Alternatively, by using a polypropylene film made of a mixture of a polypropylene having a syndiotactic structure and a polypropylene having an isotactic structure, and laminating with the base film 1 via the ionizing radiation-curable adhesive 2, ionizing radiation It becomes possible to extremely suppress the generation of the decomposition odor generated from the laminated material 10 by the irradiation, and it becomes highly practical.

This is because the syndiotactic polypropylene has a different crystal structure from the conventional isotactic polypropylene due to the difference in the three-dimensional structure, as described above. By this, polypropylene with syndiotactic structure is superior to polypropylene with isotactic structure in that decomposition and degradation of resin upon irradiation with ionizing radiation are suppressed, and mechanical strength is reduced and furthermore, generation of decomposition odor is extremely small. Has performance.

Further, by using a polypropylene obtained by mixing a polypropylene having an isotactic structure with a polypropylene having a syndiotactic structure to such an extent that the radiation resistance is not reduced, it is possible to achieve a better result than when polypropylene having a syndiotactic structure is used alone. In addition, it is possible to improve film forming property, transparency, and the like when forming a film.

Even if the laminated material formed by the above-mentioned means is formed into a package, for example, a bag-like package for food packaging or a lid for a packaging container, even if the content is affected by the irradiation of ionizing radiation. It is possible to obtain a package having almost no odor transfer.

[0055]

The present invention will be described in more detail with reference to the following examples. <Example 1> OP having a thickness of 20 µm was used as a base film.
Printed matter of P film (Futamura Chemical Co., Ltd., FOR) (Ink: Toyo Ink Mfg. Co., Ltd., NEW LP Super)
And an ionizing radiation-curable adhesive composed of 100 parts of a prepolymer (molecular weight: 12,000) of ether urethane acrylate heated to 80 ° C. and 20 parts of nonylphenyloxyacrylate (viscosity: 1050 mPa · s, at 80 ° C.)
To the printing surface by a roll coating method so as to have a coating amount of 3 g / m ² , and then as a sealant film,
Syndiotacticity 0.92, molecular weight distribution Mw /
A crimping roll temperature of 50 ° C., a crimping pressure of 5 kg / cm ² and a corona-treated surface of a 30 μm thick syndiotactic polypropylene (homo) film composed of Mn = 4,
After pressure bonding at a processing speed of 100 m / min, an electron beam is accelerated from a syndiotactic polypropylene film side in a nitrogen atmosphere at an acceleration voltage of 150 kV and an absorbed dose of 25 k.
It was irradiated with Gy and wound up to obtain a laminated material (sample 1).

Example 2 A laminated material (sample 2) was prepared in the same manner as in Example 1 except that a polypropylene (homo) film having a syndiotactic structure having a syndiotacticity of 0.70 was used as the sealant film. I got

Example 3 In Example 1, a polypropylene (homo) polymer having a syndiotactic structure having a syndiotacticity of 0.92 and a molecular weight distribution of Mw / Mn = 4 was polymerized on a sealant film with a Ziegler-Natta catalyst. Isotacticity 0.9
8. 90/1 with polypropylene (homo) polymer of isotactic structure having molecular weight distribution Mw / Mn = 6
A laminated material (sample 3) was obtained by the same operation except that a polypropylene film composed of 0 parts by weight of the mixture was used.

Example 4 In Example 1, a polypropylene (homo) polymer having a syndiotactic structure having a syndiotacticity of 0.92 and a molecular weight distribution of Mw / Mn = 4 was polymerized on a sealant film from a Ziegler-Natta catalyst. Except that a polypropylene film consisting of a 90/10 parts by weight of a blended ethylene-propylene random copolymer having an isotactic structure (ethylene content: 3.8%, isotacticity 0.92) was used. By the same operation, a laminated material (sample 4) was obtained.

Example 5 In Example 1, a polypropylene (homo) polymer having a syndiotactic structure having a syndiotacticity of 0.92 and a molecular weight distribution of Mw / Mn = 4 was polymerized on a sealant film with a Ziegler-Natta catalyst. Except that a polypropylene film consisting of 70/30 parts by weight of a mixed ethylene-propylene random copolymer having an isotactic structure (ethylene content: 3.8%, isotacticity 0.92) was used. By the same operation, a laminated material (sample 5) was obtained.

<Example 6> In Example 1, an ethylene-propylene random copolymer having a syndiotactic structure (ethylene content 2%,
A laminated material (sample 6) was obtained by the same operation except that a polypropylene film having a polysyndiotactic structure consisting of syndiotacticity 0.89) was used.

Example 7 In Example 1, an ethylene-propylene random copolymer having a syndiotactic structure (ethylene content 2%,
Polypropylene comprising a mixture of 80/20 parts by weight of syndiotacticity 0.89) and an ethylene-propylene random copolymer having an isotactic structure (ethylene content: 3.8%, isotacticity 0.92) A laminated material (Sample 7) was obtained by the same operation except that a film was used.

Comparative Example 1 In Example 1, an ethylene-propylene random copolymer having an isotactic structure (ethylene content: 3.8%, isotacticity 0.9) used in Example 4 was used as a sealant film.
A laminated material (Comparative Sample 1) was obtained by the same operation except that the polypropylene film composed of 2) was used.

Comparative Example 2 In Example 1, the ethylene-propylene random copolymer having the isotactic structure used in Example 4 (ethylene content: 3.8%, isotacticity: 0.1%) was used as the sealant film in Example 4. 92) As a stabilizer, a polycondensate of succinic acid and N- (2-hydroxyethyl) -2,2,6,6 tetramethyl-4-hydroxypiperidine (100% by weight) (Ciba Special Chemicals, Tinuvin) 622), 0.15 parts by weight of tris- (2,4-di-tert-butylphenyl) phosphite (Irgafos 168, Ciba Special Chemicals), tetrakis-
[Methylene (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] The same as the above except that a polypropylene film obtained by mixing 0.1 part by weight of methane (Ciba Special Chemicals, Irganox 1010) was used. A laminated material (Comparative Sample 2) was obtained by the operation.

Each of the laminated materials (Samples 1 to 7 and Comparative Samples 1 and 2) obtained in Examples 1 to 7 and Comparative Examples 1 and 2 was evaluated for odor generated from the film.
Table 1 shows the results.

<Measurement of Odor>
It was cut into cm ² , packed in an odor collection bottle together with activated carbon as an odor collector, and stored in an 80 ° C. oven for 1 day. Thereafter, the activated carbon was taken out, the adsorbed substance was extracted with carbon disulfide, and the adsorbed substance was identified and quantified by gas chromatography analysis. Carboxylic acids (acetic acid, propionic acid, n-butyric acid, n-
-Valeric acid), and evaluated by the quantitative value.
Table 1 shows the quantitative values of acetic acid in the above carboxylic acids converted into unit area (square meter) of the laminated material. That is, the smaller this value is, the smaller the generation of decomposition odor is.

[0066]

[Table 1]

As is clear from the results shown in Table 1, the laminated materials of Examples 1 to 7 according to the present invention (Samples 1 to 7)
It can be seen that the odor generated after irradiation with ionizing radiation is significantly improved as compared with Comparative Examples 1 and 2 (Comparative Samples 1 and 2) according to the conventional method.

Example 8 The laminated material prepared in Example 1 was made into a bag, and a 200 mm × 250 mm pouch was prepared. Next, the pouch was filled with deodorized air through activated carbon, stored at room temperature for 3 days, and used for sensory evaluation of odor.

<Comparative Example 3> A pouch was prepared in the same manner as in Example 8 except that the laminated material prepared in Comparative Example 1 was used, and used for sensory evaluation of odor.

The odors in the pouch of Example 8 and the pouch of Comparative Example 3 were subjected to a sensory test by 15 panelists according to the paired comparison method. As a result, the pouch of Example 8 had a lower odor at a significance level of 1%. It was confirmed that. Further, the melting point of the syndiotactic polypropylene (homo) film used in Example 8 was about 130 ° C., and the polypropylene film made of the isotactic ethylene-propylene random copolymer used in Comparative Example 3 was used. About 14
Since the temperature is lower by about 15 ° C. than that of 5 ° C., it has been found that there is an advantage that the low-temperature heat sealability is excellent and the productivity at the time of bag making can be improved.

<Embodiment 9> An embodiment in which a standing bag is formed using the laminated material of the present invention will be described. 12 μm thick PET film (Toyobo Co., Ltd.
E5102) printed matter (ink: Toyo Ink Mfg. Co., Ltd., NEW LP Super) and a 15 μm thick O
A prepolymer (molecular weight: 1200) of a NY film (Unitika Co., Ltd., ONM) was coated by heating at 80 ° C. by a roll coating method.
0) 100 parts and nonylphenyloxyacrylate 20
Radiation curable adhesive (viscosity: 1030 m)
Pa · s, at 80 ° C., coating amount: 3 g / m ² )
After pressing under the conditions of a pressing roll temperature of 50 ° C., a pressing pressure of 5 kg / cm ² , and a processing speed of 100 m / min, an electron beam was accelerated from the PET film side under a nitrogen atmosphere at an accelerating voltage of 150 kV.
Irradiation was performed at an absorbed dose of 25 kGy. Further, a thickness of 130 μm having a syndiotacticity of 0.92 and a molecular weight distribution of Mw / Mn = 4 was applied to the ONY film surface of the laminated material using the ionizing radiation-curable adhesive (application amount: 3 g / m ² ). After pressing a polypropylene (homo) film having a syndiotactic structure under the same conditions as above, an electron beam was accelerated from the PET film side at an acceleration voltage of 150 kV and an absorbed dose of 2
Irradiate at 5 kGy and wind up, OPET 12 μm / print / ADH / ONY 15 μm / ADH / SPP 130 μm
The laminated material used as the trunk | drum member of the standing bag of the structure of the above was obtained.

Next, a printed matter (ink: Toyo Ink Mfg. Co., Ltd., NEW LP Super) of ONY film (Unitika Co., Ltd., ONM) having a thickness of 15 μm, syndiotacticity 0.92, molecular weight distribution Mw / Mn = And a polypropylene (homo) film having a syndiotactic structure having a thickness of 120 μm and a pressure of 150 kV and an absorbed dose of 25 kG from the ONY film side under a nitrogen atmosphere.
Irradiate with y, ONY15μm / ADH / SPP120μ
Thus, a laminated material serving as the bottom member of the standing bag having the structure of m was obtained. Next, a standing bag was formed by heat-sealing the trunk member and the bottom member according to a conventional method.

Sensory evaluation of the odor of this standing bag showed no problem. Also, after filling the standing bag with water and storing it at -5 ° C for 2 days, a drop test was performed from a height of 1m, but it did not break and had practical drop impact resistance. Was also confirmed.

<Embodiment 10> An embodiment in which a bag-in-box is formed using the laminated material of the present invention will be described. ONY film with a thickness of 15 μm (Kojin Co., Ltd.
Ionizing radiation-curable adhesive (viscosity: 1030 mPa) comprising 100 parts of a prepolymer (molecular weight: 12,000) of ether urethane acrylate and 20 parts of nonylphenyloxy acrylate, which are heated and applied at 80 ° C. by a roll coating method on both sides of the film. S, at 80 ° C., coating amount: 4 g / m ² ), each having a syndiotacticity of 0.92 and a molecular weight distribution Mw / M having a thickness of 60 μm.
After pressing a polypropylene (homo) film having a syndiotactic structure consisting of n = 4 under the conditions of a pressing roll temperature of 50 ° C., a pressing pressure of 5 kg / cm ² , and a processing speed of 100 m / min, the electron beam is accelerated in a nitrogen atmosphere. Voltage 150k
V, irradiate with an absorbed dose of 25 kGy and wind up, SPP6
0 μm / ADH / ONY15 μm / ADH / SPP60
A laminated material to be an outer bag of a bag-in-box having a structure of μm was obtained.

Next, a 90 μm thick syndiotacticity 0.92 serving as an inner bag of the bag-in-box,
A bag-in-box was formed by heat-sealing a polypropylene (homo) film having a syndiotactic structure having a molecular weight distribution of Mw / Mn = 4 and the laminated material by a known molding method.

A sensory test for the odor of this bag-in-box was carried out, and the level was no problem. In addition, a bag-in-box was filled with soy sauce and a transport test was conducted. As a result, no problems such as leakage or breakage of the bag occurred, and it was confirmed that the bag had practical performance. In addition, the bag-in-box is usually sterilized before filling the contents, but in the laminated material of the present invention, in order to cure the ionizing radiation-curable adhesive, an electron beam having sufficient energy for sterilization is already used. Since the laminated material is irradiated with such a material, there is an advantage that it is not necessary to perform a sterilization treatment again.

<Example 11> An example in which a sterilized medical packaging material such as a medical syringe is formed by using the laminated material of the present invention will be described. An ether urethane acrylate pre-coated on a 12 μm thick PET film (Toyobo Co., Ltd., E5102) printed matter (ink: Toyo Ink Mfg. Co., Ltd., NEW LP Super) heated at 80 ° C. by a roll coating method. Polymer (molecular weight 12000)
An ionizing radiation-curable adhesive comprising 100 parts and 20 parts of nonylphenyloxyacrylate (viscosity: 1030 mPa
S, at 80 ° C., coating amount: 2 g / m ² ), a polypropylene (homo) film having a syndiotactic structure having a syndiotacticity of 0.92 and a molecular weight distribution of Mw / Mn = 4 having a thickness of 50 μm, Crimping roll temperature 5
0 ° C, pressure 5kg / cm ² , processing speed 100m / m
After pressure bonding under the conditions of "in", an electron beam was irradiated under an atmosphere of nitrogen at an acceleration voltage of 150 kV and an absorbed dose of 25 kGy and wound up to obtain a laminated material for a sterile medicine packaging material having a structure of PET 12 μm / print / ADH / SPP 50 μm. .

Conventionally, in the method of sterilizing a sterilized medicine packaging material, a sterilization step using γ-rays or ethylene oxide (EOG) is separately performed after a laminated material is prepared. At the time of fabrication, since the laminated material was already irradiated with an electron beam or the like having energy sufficient for sterilization, there was no need to perform a sterilization step again.

In general, a sterilized pharmaceutical packaging material to be sterilized by γ-ray is obtained by heat-sealing the laminated material having the above-mentioned structure and sterilized paper by a special method, and forming the laminated material by γ-ray irradiation. A device has been devised to release the decomposition odor generated from the plastic. However, using the laminated material according to the present invention, a pouch of 150 mm x 100 mm was prepared, filled with deodorized air through activated carbon in the pouch, stored at room temperature for 3 days, and subjected to sensory evaluation of odor. There was no problem level. For this reason, there is an advantage that a special structure as in the related art is not required. However, assuming a case where the required physical properties are higher, it was possible to form a sterilized medical packaging material by combining the laminated material according to the present invention with sterilized paper, as in the related art.

<Example 12> An example in which a liquid paper container is formed using the laminated material of the present invention will be described. 12 μm thick PET film (Toyobo Co., Ltd.
E5102), an ionizing radiation-curable adhesive (viscosity: 1030 mPa) composed of 100 parts of a prepolymer (molecular weight: 12000) of ether urethane acrylate and 20 parts of nonylphenyloxyacrylate, which was heated and applied at 80 ° C. by a roll coating method to one side thereof.・ S, at 80 ° C., coating amount: 5 g / m ² ), through which an aluminum foil having a thickness of 7 μm is
After pressing under the conditions of a pressing roll temperature of 50 ° C., a pressing pressure of 5 kg / cm ² , and a processing speed of 100 m / min, an electron beam was accelerated from the PET film side under a nitrogen atmosphere at an accelerating voltage of 150 kV.
It was irradiated with an absorbed dose of 30 kGy and wound up. Then, P
On the other side of the ET film, a syndiotacticity of 0.92 having a thickness of 60 μm and a molecular weight distribution Mw / Mn =
After pressing a polypropylene (homo) film having a syndiotactic structure consisting of No. 4 under the same conditions as above, an electron beam was accelerated from the PET film side in a nitrogen atmosphere at an acceleration voltage of 150.
Irradiation with kV, absorbed dose of 30 kGy and winding, aluminum foil 7 μm / ADH / PET 12 μm / ADH / SP
A laminated material to be an inner layer material of a liquid paper container having a P of 60 μm was obtained.

Next, a basis weight of 360 g / m^TwoPE on paper
The space of the laminated base paper and the laminated material forming the inner layer material
Coating resin with ethylene and methacrylic acid
(MI = 10 g / 10 min, methacrylic acid content 12
%, Density 0.930 g / cm ^Three, Hereinafter abbreviated as EMAA)
At an extrusion temperature of 300 ° C and a thickness of 20 µm
After extrusion lamination, print on the outermost PE surface.
By doing, printing / PE / paper / EMAA 20 μm / A
Lumi foil 7μm / ADH / PET 12μm / ADH /
A laminated material for a liquid paper container having an SPP of 60 μm was obtained.
From this laminated material, according to a known method,
A lip-shaped liquid paper container was formed.

The liquid paper container was filled with water, and taste sensory evaluation was carried out. As a result, good results were obtained without transfer of off-flavor components due to irradiation with ionizing radiation. Similarly, a transport test was performed using the liquid paper container filled with water, but no problem such as leakage or breakage occurred, and a liquid paper container molded using the laminated material of the present invention was practical. It was confirmed that it had performance.

Embodiment 13 An embodiment in which another liquid paper container is formed using the laminated material of the present invention will be described.
100 parts of a prepolymer (molecular weight: 12000) of ether urethane acrylate, which was heated at 80 ° C. by a roll coating method and applied to a silicon oxide-deposited surface of a SiOVM-PET film obtained by depositing 500 ° silicon oxide on a PET film having a thickness of 12 μm, and nonyl Ionizing radiation curable adhesive comprising 20 parts of phenyloxyacrylate (viscosity: 1
030 mPa · s, at 80 ° C., coating amount: 4 g / m ² ), a 50 μm-thick polypropylene (homo) film having a syndiotactic structure (syndiotacticity 0.92, molecular weight distribution Mw / Mn = 4). At a pressing roll temperature of 50 ° C., a pressing pressure of 5 kg / cm ² , and a processing speed of 1.
After pressure bonding under the condition of 00 m / min, an electron beam is irradiated under an atmosphere of nitrogen at an acceleration voltage of 150 kV and an absorbed dose of 25 kGy and wound up, and SiOVM-PET 12 μm / ADH /
A laminated material to be the inner layer material of the liquid paper container having the SPP of 50 μm was obtained.

Next, the paper surface of the base paper obtained by laminating PE on paper having a basis weight of 360 g / m ² and the S
The iOVM-PET surface was combined with an LDPE resin (MI = 5 g /
10 min, density 0.920 g / cm ³ ), extrusion extrusion lamination at 320 ° C. and thickness 15 μm, followed by printing on the PE surface of the outermost layer, whereby printing / PE / paper / LDPE 15 μm / SiOV
A laminated material for a liquid paper container having a configuration of M-PET 12 μm / ADH / SPP 50 μm was obtained. From this laminated material,
According to a known method, a Goebel top type liquid paper container was formed.

This liquid paper container was filled with water and subjected to taste sensory evaluation in the same manner as in Example 12, and good results were obtained without transfer of off-flavor components due to irradiation with ionizing radiation. Similarly, a transport test was performed using the liquid paper container filled with water, but no problem such as leakage or breakage occurred, and a liquid paper container molded using the laminated material of the present invention was practical. It was confirmed that it had performance.

<Example 14> An example in which a laminated tube was formed using the laminated material of the present invention will be described. A white polyethylene film having a thickness of 50 μm and an aluminum foil having a thickness of 15 μm were mixed with a copolymer resin of ethylene and acrylic acid (MI = 10 g / 10 min, acrylic acid content 7%, density 0.935 g / cm ³ , hereinafter referred to as EA).
A), extrusion temperature 300 ° C, thickness 20μm
After laminating by sandwich extrusion, printing on the white PE surface of the outermost layer (Ink: Toyo Ink Manufacturing Co., Ltd., NE
WLP Super), a thickness of 80
A polypropylene (homo) film (syndiotacticity 0.92, molecular weight distribution Mw / Mn = 4) having a syndiotactic structure of μm was coated with a roll coat method to form a film of 8 μm.
An ionizing radiation-curable adhesive (viscosity: 1030 mPa · s, at80) composed of 100 parts of a prepolymer (molecular weight: 12,000) of ether urethane acrylate, which was heated and applied at 0 ° C., and 20 parts of nonylphenyloxyacrylate.
° C, application amount: 5 g / m ² )
0 ° C, pressure 5kg / cm ² , processing speed 100m / m
After pressure bonding under the conditions of “in”, an electron beam is irradiated under an atmosphere of nitrogen at an accelerating voltage of 150 kV and an absorbed dose of 25 kGy and wound up, so that SPP 80 μm / ADH / print / white PE
50μm / EMA 20μm / aluminum foil 15μm / A
A laminated material to be a body member of a laminated tube having a DH / SPP of 80 μm was obtained.

After the obtained laminated material is molded into a tubular shape by a high frequency sealing method, the mouth of the tube is integrally molded by a known method using a polypropylene (homo) resin having the same syndiotactic structure as described above. Then, a laminated tube was obtained.

The sensory evaluation of the odor of the laminate tube showed no problem. Further, in order to evaluate the content resistance, the laminated tube was filled with toothpaste as a content, but no significant decrease in adhesion such as delamination (delamination) over time was observed. Further, no troubles such as leakage or bag breakage at the time of or after filling of the contents occurred, and it was confirmed that the laminated tube molded using the laminated material of the present invention had practical performance.

Example 15 An example in which a package for boiling was formed using the laminated material of the present invention will be described. Printed surface of a 15 μm thick ONY film (Unitika Co., Ltd., ONM) (ink: Toyo Ink Mfg. Co., Ltd., NEW LP Super) and thickness 6
A polypropylene (homo) film having a syndiotactic structure of 0 μm (syndiotacticity 0.92, molecular weight distribution Mw / Mn = 4) was heated at 80 ° C. by a roll coating method to apply ether urethane acrylate. Pressure bonding roll temperature 50 ° C, pressure bonding via an ionizing radiation curable adhesive (viscosity: 1030 mPa · s, at 80 ° C, application amount: 4 g / m ² ) consisting of 100 parts of polymer (molecular weight) and 20 parts of nonylphenyloxyacrylate After pressure bonding under the conditions of a pressure of 5 kg / cm ² and a processing speed of 100 m / min, an electron beam is irradiated from the ONY film side in an atmosphere of nitrogen at an acceleration voltage of 150 kV and an absorbed dose of 25 kGy and wound up, so that ONY is 15 μm / print / ADH. /
A laminated material to be a boiled package having a SPP of 60 μm was obtained.

The laminated material was made into a bag,
A 0 mm pouch was made. Next, the pouch was filled with water and subjected to a boil sterilization treatment at 80 ° C. for 30 minutes.
No problems such as breakage of the bag, delamination, and poor appearance of the pouch did not occur. Further, a taste sensory test of water in the boiled pouch was performed using comparative samples shown below.

<Comparative Example 4> Instead of the polypropylene (homo) film having a syndiotactic structure having a thickness of 60 μm (syndiotacticity 0.92, molecular weight distribution Mw / Mn = 4) in the laminated material of Example 15, Example 15 was repeated using a polypropylene film composed of an ethylene-propylene block copolymer having an isotactic structure (ethylene content: 3.8%, isotacticity: 0.92) polymerized by a Ziegler-Natta catalyst. A similar pouch was made. Next, the pouch was filled with water, subjected to a boil sterilization treatment under the same conditions as in Example 15, and used for a sensory comparison test of the taste of water of the contents.

<Comparative Example 5> In the laminated material of Example 15, an ionizing radiation-curable adhesive (viscosity: 1030 mPa ·
s, at 80 ° C., coating amount: 4 g / m ² ) instead of a conventionally used solvent-based two-part curable urethane adhesive (Toyo Morton Co., Ltd .: AD-806 / AD-RT8).
And applying the urethane-based adhesive diluted with a solvent (ethyl acetate) on the printing surface of the ONY film to a coating amount of 4 g / m ² by a gravure coating method.
After drying in an oven to volatilize the solvent, the pressing roll temperature was 50 ° C., the pressing pressure was 5 kg / cm ² , and the processing speed was 1
After crimping under the condition of 00 m / min, it was wound up. afterwards,
After storing in a warm dry room at 50 ° C. for 4 days to cure the adhesive, a pouch similar to that of Example 15 was produced. Next, the pouch was filled with water, subjected to a boil sterilization treatment under the same conditions as in Example 15, and used for a sensory comparison test of the taste of water of the contents.

The taste of water after the boil treatment in Example 15 was compared with the taste of water in Comparative Examples 4 and 5 by sensory evaluation. The results of Example 15 and Comparative Example 4 were significantly different. A difference was obtained, and it was confirmed that Example 15 exhibited a better taste than Comparative Example 4. Further, no significant difference was observed with respect to Comparative Example 5, and it was confirmed that the package had the same taste performance as the boiled package produced by the conventional method. Furthermore, the pouch of Example 15 was subjected to a transportation test after the boil treatment, but no problems such as leakage and bag breakage occurred, and the boiled package formed using the laminated material of the present invention exhibited practical performance. It was confirmed that it had.

[0094]

As described above in detail, according to the laminated material of the present invention, the sealant film has a syndiotactic structure of polypropylene or syndiotactic polypropylene, which is extremely little decomposed and deteriorated by irradiation with ionizing radiation. Since a film formed by using a mixture of a specific ratio of polypropylene having a tic structure and polypropylene having an isotactic structure is used, in recent years, through an ionizing radiation-curable adhesive which has a great effect on improving productivity. In the case of laminating, the generation of decomposition odor, which is mainly a problem from the plastic film, can be significantly suppressed.

Accordingly, the laminated material obtained by laminating the sealant film according to the present invention with an ionizing radiation-curable adhesive is particularly useful in food packaging applications where generation of an off-flavor is problematic, ie, the above-mentioned snack confectionery, rice confectionery, instant Snacks such as ramen and hygroscopic foods, processed fats and oils such as potato chips and fried rice crackers, and chilled and
Standing bags used for packaging containers for frozen foods, refillable liquid detergents, etc., pharmaceutical packaging materials for sterilization, bag-in-boxes, laminate tubes, packaging for boiling, liquid paper containers, various trays to be deep drawn, It can be used for lid materials.

The package made of the laminated material of the present invention not only has an improved odor, but also has the required characteristics such as the content, shape, internal capacity, shelf life, packaging form, and distribution environment conditions of various packages. And can be used without any problem. Not only that, in some packages such as bag-in-boxes and medical packaging materials for sterilization, conventionally, after forming a laminated material, radiation sterilization using γ-rays or the like is performed in a separate process. Since the package is irradiated with ionizing radiation (electron beam, etc.) with sufficient energy for sterilization when the ionizing radiation-curable adhesive is cured, there is no need to perform another sterilization treatment in another process.
It also has the effect of further streamlining the production process. As described above, the package obtained by using the laminated material of the present invention makes a great contribution in the field of packaging.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a laminated material of the present invention.

[Explanation of symbols]

 1: base film 2: ionizing radiation-curable adhesive 3: sealant film 10: laminated material

Claims (8)

[Claims] 1. A laminated material obtained by laminating a base film comprising at least one or more films and a sealant film via an ionizing radiation-curable adhesive, wherein the sealant film has a syndiotactic structure such as polypropylene or syndiotactic. A laminated material comprising a mixture of polypropylene having a tic structure and polypropylene having an isotactic structure. 2. The composition according to claim 1, wherein the mixing weight ratio of the polypropylene having the syndiotactic structure and the polypropylene having the isotactic structure is 30/70 to 99/1, preferably 70/30 to 99/1. Laminated material. 3. The polypropylene having the syndiotactic structure has a syndiotacticity of 0.5 or more,
The laminated material according to claim 1 or 2, wherein the thickness is preferably 0.7 or more. 4. The laminated material according to claim 1, wherein the polypropylene having a syndiotactic structure is a copolymer with another α-olefin. 5. A package formed into a desired shape using a laminated material obtained by laminating a base film comprising at least one or more films and a sealant film via an ionizing radiation-curable adhesive. , Wherein the sealant film is made of polypropylene having a syndiotactic structure. 6. The mixed weight ratio of the polypropylene having a syndiotactic structure and the polypropylene having an isotactic structure is 30/70 to 99/1, preferably 70/30 to 99/1. Packaging. 7. The package according to claim 5, wherein the polypropylene having the syndiotactic structure has a syndiotacticity of 0.5 or more, preferably 0.7 or more. 8. The package according to claim 5, wherein the polypropylene having the syndiotactic structure is a copolymer with another α-olefin.