JP4651320B2 - Laminated body - Google Patents

Description

The present invention, gas barrier A-natured, heat sealability, antistatic property, to excellent laminate interlayer adhesion or the like.

High ethylene-vinyl alcohol copolymer having a vinyl alcohol content (hereinafter sometimes abbreviated as EVOH) is known as a resin excellent in gas barrier A-natured, long-term deterioration of the packaged articles oxide based Since it can be suppressed, it is widely used in the food packaging field. However EVOH is liable to absorb water it lowers the gas barrier A-natured With water absorption, or the like is not good heat sealability is seldom used alone as a packaging material, or other blended with other resins It is used by laminating with resin. For water reduction and heat seal imparting EVOH, water-blocking, it is effective to laminate a high-pressure low-density polyethylene and linear, low density polyethylene having excellent heat-sealing properties and the like, good adhesion to the EVOH Therefore, various methods for improving adhesion have been studied. For example, many methods using a carboxylic acid-modified polyolefin resin or a composition thereof as an adhesive have been proposed.

The polyester resin, particularly biaxially stretched polyethylene terephthalate film (hereinafter sometimes abbreviated as O-PET) is not enough to match the EVOH is excellent in gas barrier A-natured, also tough and high transparency Because of its properties, it is widely used as a base material for packaging materials such as various foods and industrial materials. Since O-PET also has poor heat sealing performance, a sealant resin is generally laminated and used for applications requiring heat sealing. However, since the adhesion between O-PET and the sealant resin is poor, various formulations for improving the adhesion between the two have been studied.

In the food packaging applications utilizing these gas barrier A chromatography material, as a separate issue, storage, at each stage, such as transportation adheres dust in the air, the surface is contaminated, the powder food packaging In the case of use, a packaging material is desired in which the content of the product adheres to the inner surface of the bag and the appearance of the bag is damaged. However, in the conventionally proposed EVOH / carboxylic acid-modified polyolefin-based resin or its composition / polyethylene laminate such as polyethylene or O-PET laminate, the contamination resistance is essentially low. This is not sufficient, and the drawbacks have been compensated by adding an antistatic agent to the surface layer. However, since the antistatic agent bleeds to the surface of the laminate over time, the antistatic effect decreases over time, and further, there is a concern about contamination of the package.

Accordingly, an object of the present invention is to provide a suitable gas barrier A-natured as food packaging materials, heat sealability, interlayer adhesion, a laminate of superior EVOH or polyester resin stain resistance.

According to the present invention, there is provided a three-layer laminate in which a base material layer made of an ethylene / vinyl alcohol copolymer , an adhesive layer, and a polyolefin sealant layer are laminated in this order, and the adhesive layer is made of an ethylene / unsaturated carboxylic acid copolymer. It is composed of a polymer potassium ionomer or a composition thereof, and both the adhesive strength between the base material layer and the adhesive layer and the adhesive strength between the adhesive layer and the sealant layer are 2 N / 15 mm or more, and at least one of the base material layer and the sealant layer The surface is provided with a laminate having a 10% decay time of 1 second or less at an applied voltage of 5000V.

According to the present invention, it is possible to provide gas barrier A-natured, heat sealability, antistatic property, an excellent laminate interlayer adhesion. Such a laminate is excellent in charge attenuation, can prevent the adhesion of dust and powder due to charging, and has excellent contamination resistance. Such a laminate can be used in the form of, for example, a film, a tape, a sheet, a tube, a tube, a bag, a multilayer container (for example, a container by blow molding), various blow molded products, and the like. In this case, the molded article base material layer having the above-mentioned attenuation characteristics outside surface has excellent stain resistance, it is possible to avoid surface contamination, gas barrier A-natured, heat sealability, interlayer adhesion Since it is excellent, it is suitable as a packaging material. In particular, when used as a packaging material for powder materials and the polyolefin sealant layer having the above-mentioned damping characteristics becomes the inner surface layer, there is no electrostatic adhesion of the powder to the packaging material, and the commercial value is impaired. There is no.

  In addition to food packaging materials and other various packaging materials, the laminate of the present invention is a semiconductor adhesive tape or film such as a dicing tape substrate or back grind film, a marking film, an IC carrier tape, an electronic component taping tape, etc. Electrical / electronic materials, hygiene materials, protective films (eg glass, plastic or metal boards, lens guard films or tapes), steel wire coating materials, clean room curtains, wallpaper, mats, flooring and other building materials, in flexible containers It can be used in applications such as bags, containers, shoes, battery separators, antifouling films, dustproof films, PVC substitute films, various cosmetics, detergents, shampoos, rinses, and tubes and bottles.

  In order to make use of the surface attenuation characteristics and other characteristics of the laminate of the present invention, other materials such as base materials such as biaxially stretched films or sheets such as polyamide and polypropylene, or acrylic resins, polycarbonates, ABS resins, polystyrenes, etc. It can be used by being laminated on a material including a plate-shaped molded product such as styrene-based resin or polyacetal. When used as such a stain-resistant skin material, the sealant layer is laminated so as to come into contact with the other material, or is laminated via an adhesive layer. As other materials used for such purposes, various plastic materials, films such as paper, wood, metal, sheets, sheets, foams, woven fabrics, non-woven fabrics and the like can be used. As the adhesive layer, rubber-based, acrylic-based, silicon-based adhesives, and the like can be used.

  In the laminate of the present invention, the ethylene-vinyl alcohol copolymer that can be used as the base material is a copolymer of ethylene and vinyl alcohol having a high vinyl alcohol content, and if it is a small amount, it contains other monomers. May be. Generally, the vinyl alcohol content is 50 to 85 mol%, preferably 55 to 80 mol%. Such a copolymer can be obtained by saponifying a corresponding ethylene / vinyl acetate copolymer at a saponification degree of 80% or more, preferably 95% or more. The ethylene / vinyl alcohol copolymer also has a melt flow rate (JIS K7210-1999, hereinafter the same) at 210 ° C. under a load of 2160 g of 0.1 to 50 g / 10 min, particularly about 0.5 to 30 g / 10 min. It is better to use something.

In the laminate of the present invention, the polyester resin can be used as a base layer material, transparency, heat resistance, toughness, from the viewpoint of gas barrier A-natured, those acid component mainly comprising an aromatic dicarboxylic acid In particular, those containing terephthalic acid or 2,6-naphthalenedicarboxylic acid in an amount of 80 mol% or more, preferably 90 mol% or more are preferred. Other acid dicarboxylic acids such as isophthalic acid and phthalic acid, as well as alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, aliphatic dicarboxylic acids such as adipic acid and sebacic acid, etc. It may be included as a copolymerization component. As long as the amount is smaller, trivalent or higher polyvalent carboxylic acid such as trimellitic acid, hemimellitic acid and pyromellitic acid may be included as a copolymerization component.

  Examples of the dihydroxy compound component constituting the polyester resin include ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, and aliphatic glycols such as triethylene glycol. Examples include alicyclic diols such as 1,4-cyclohexanediol and aromatic dihydroxy compounds such as bisphenol A ethylene oxide adducts. Of these, those containing 80 mol% or more, preferably 90 mol% or more of ethylene glycol, 1,3-propylene glycol or 1,4-butanediol are preferred. In addition, as long as it is a small amount, it may contain a trifunctional or higher polyvalent hydroxy compound such as glycerin or trimethylolpropane.

  Typical polyester resins include polyethylene terephthalate, polyethylene-2,6-naphthalene dicarboxylate, polytrimethylene terephthalate, polybutylene terephthalate, and the like.

  Such a polyester resin also has an intrinsic viscosity measured at 20 ° C. at a concentration of 0.4 g / 100 ml in a 47/53 (volume ratio) mixed solvent of trifluoroacetic acid / methane dichloride in a 47/53 (volume ratio) mixed solvent. Those in the range of 4 dl / g, particularly 0.6 to 1.0 dl / g are preferred. A melting point (temperature showing a maximum endothermic peak based on a differential scanning calorimeter) is 210 ° C. or higher, particularly 220 ° C. or higher.

  In the laminate of the present invention, an adhesive layer composed of a potassium ionomer of an ethylene / unsaturated carboxylic acid copolymer or a composition thereof adjacent to a base material layer made of an ethylene / vinyl alcohol copolymer or a polyester resin. Is provided. The ethylene / unsaturated carboxylic acid copolymer used as the base polymer of the potassium ionomer is obtained by copolymerizing ethylene, an unsaturated carboxylic acid, and optionally another polar monomer.

  Examples of the unsaturated carboxylic acid in the ethylene / unsaturated carboxylic acid copolymer of the base polymer include acrylic acid, methacrylic acid, fumaric acid, maleic anhydride, monomethyl maleate, monoethyl maleate, etc. Acrylic acid or methacrylic acid is preferred. Other polar monomers that can be copolymer components include vinyl esters such as vinyl acetate and vinyl propionate, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, and n-acrylate. -Unsaturated carboxylic acid esters such as hexyl, isooctyl acrylate, methyl methacrylate, ethyl methacrylate, dimethyl maleate, diethyl maleate, carbon monoxide, etc., especially unsaturated carboxylic acid esters are suitable copolymerization components It is.

  Such an ethylene / unsaturated carboxylic acid copolymer can be obtained by radical copolymerization of ethylene and an unsaturated carboxylic acid and optionally another polar monomer at high temperature and high pressure.

  If potassium ionomer is used as the base polymer having an ethylene / unsaturated carboxylic acid copolymer with a low acid content or a neutralization degree that is too small, the surface of the base material layer and / or the polyolefin sealant layer will be In addition, it is not easy to obtain a laminate having excellent non-charging properties such that a 10% decay time at an applied voltage of 5000 V is 1 second or less. Therefore, the degree of neutralization with potassium ions of an ethylene / unsaturated carboxylic acid copolymer having an unsaturated carboxylic acid content of 10 to 30% by weight, preferably 10 to 25% by weight, is 60% or more, preferably 70% or more. It is preferable to use one or more ionomers. In particular, it is desirable to use potassium ionomers of two or more ethylene / unsaturated carboxylic acid copolymers having different average acid contents. For example, two or more kinds of copolymers having an average acid content of 10 to 30% by weight, preferably 10 to 20% by weight, wherein the difference in acid content between the highest acid content and the lowest acid content is 1% by weight or more, Preferably, it is a mixed ionomer having an ethylene / unsaturated carboxylic acid copolymer having a difference of 2 to 20% by weight with a degree of neutralization with potassium ions of 60% or more, preferably 70% or more. More specifically, the unsaturated carboxylic acid content is 1 to 10% by weight, preferably 2 to 10% by weight, 190 ° C., melt flow rate at 2160 g load is 1 to 600 g / 10 minutes, preferably 10 to 500 g / 10. Minute ethylene / unsaturated carboxylic acid copolymer (A-1) and unsaturated carboxylic acid content of 11 to 25% by weight, preferably 13 to 23% by weight, 190 ° C., melt flow rate at 2160 g load is 1 to 1%. It consists of an ethylene / unsaturated carboxylic acid copolymer (A-2) of 600 g / 10 minutes, preferably 10 to 500 g / 10 minutes, and has an average unsaturated carboxylic acid content of 10 to 20% by weight, preferably 11 to 15%. Weight average, 190 ° C., average melt flow rate at 2160 g load is 1 to 300 g / 10 min, preferably 10 to 200 g / 10 min, more preferably Mixed ionomers having the degree of neutralization of the mixed copolymer components 0~150g / 10 min are particularly preferred. As the mixed copolymer component, the mixing ratio of the copolymer (A-1) and the copolymer (A-2) is 2-60 parts by weight of the former, preferably 5-50 parts by weight with respect to the latter. 98 to 40 parts by weight, preferably 95 to 50 parts by weight is preferred. The above-mentioned ethylene / unsaturated carboxylic acid copolymer, which is the base polymer of potassium ionomer, is copolymerized with other polar monomers as described above in a proportion of 40% by weight or less, preferably 30% by weight or less. It may be.

  As potassium ionomer, in consideration of processability and miscibility when blending other components, the melt flow rate at 190 ° C. under a load of 2160 g is 0.1 to 100 g / 10 min, particularly 0.2 to 50 g / It is preferred to use a 10 minute one.

  The adhesive layer may be composed only of the above potassium ionomer, but a composition containing other thermoplastic polymers and additives can be used as long as the non-chargeability of the laminate is not significantly impaired. Such other thermoplastic polymer is preferably selected from those exemplified as the polyolefin sealant described later, or polyether ester amide is preferably used. Among polyolefin-based sealants, ethylene homopolymers, copolymers of ethylene and α-olefins having 3 or more carbon atoms, copolymers of ethylene and unsaturated esters such as vinyl acetate and unsaturated carboxylic acid esters, etc. The use of selected ethylene polymers is preferred. It is not always necessary to use a virgin product as such an ethylene polymer. For example, when an ethylene polymer is used as a sealant layer, it is possible to recycle off-spec products generated during molding or molding waste such as ears. May be. Further, as these ethylene polymers, acid-modified products thereof, for example, maleic anhydride graft polymers may be used.

  As the polyether ester amide that can be used by blending with potassium ionomer, a block copolymer composed of a polyamide block and a polyoxyalkylene glycol block, and these blocks are connected by an ester bond is used.

  Polyamide blocks in the polyether ester amide include, for example, dicarboxylic acids such as succinic acid, succinic acid, adipic acid, sebacic acid, dodecanedioic acid, terephthalic acid, isophthalic acid, 1,4-cyclohexanedicarboxylic acid, ethylenediamine, tetramethylene Diamine, pentamethylenediamine, hexamethylenediamine, decamethylenediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4 Polycondensation with diamines such as bis (aminomethyl) cyclohexane, methylenebis (4-aminocyclohexane), m-xylylenediamine, p-xylylenediamine, lacta such as ε-caprolactam, ω-dodecalactam Ring-opening polymerization, polycondensation of aminocarboxylic acids such as 6-aminocaproic acid, 9-aminononanoic acid, 11-aminoundecanoic acid and 12-aminododecanoic acid, or copolymerization of the above lactam, dicarboxylic acid and diamine Is obtained. Examples of such polyamide segments include nylon 4, nylon 6, nylon 46, nylon 66, nylon 610, nylon 612, nylon 6T, nylon 11, nylon 12, nylon 6/66, nylon 6/12, nylon 6/610, Nylon 66/12, nylon 6/66/610 and the like, and nylon 11 and nylon 12 are particularly preferable. Further, as the polyamide block, for example, those having a molecular weight of about 400 to 5000 are used.

  Examples of the polyether block include polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol, polyoxyalkylene glycols such as polyoxyethylene / polyoxypropylene glycol, and mixtures thereof. For example, those having a molecular weight of about 400 to 6000, particularly about 600 to 5000 are preferable.

  The polyether ester amide is preferably one containing a polyoxyalkylene glycol block content of 5 to 80% by weight, particularly 15 to 70% by weight. Furthermore, it is preferable to use a melt flow rate at 230 ° C. and a load of 2160 g of 0.1 to 1000 g / 10 minutes, particularly 1 to 100 g / 10 minutes. Moreover, it is preferable to use the thing whose melting | fusing point (temperature which shows the maximum heat absorption amount) measured with a differential scanning calorimeter (DSC) is about 130-175 degreeC. Such a polyether ester amide can be obtained by reacting a nylon oligomer having a molecular weight of about 600 to 5,000, a polyoxyalkylene glycol and, if necessary, a carboxylic acid.

When blending the polyetheresteramide, it can be used in the form of its composition. As a typical example of the composition, a mixture of a polyether ester amide and an inorganic or organic protonic acid salt can be exemplified. Specific examples of inorganic or organic protonic acid salts that can be blended include LiClO ₄ , LiCF ₃ SO ₃ , NaClO ₄ , LiBF ₄ , NaBF ₄ , KBF ₄ , NaCF ₃ SO ₃ , KClO ₄ , KPF ₆ , KCF ₃ SO ₃ , KC ₄ F ₉ SO ₃ , Ca (ClO ₄ ) ₂ , Ca (PF ₆ ) ₂ , Mg (Cl ₄ ) ₂ , Mg (CF ₃ SO ₃ ) ₂ , Zn (ClO ₄ ) ₂ , Zn (PF ₆ ) ₂ , Ca (CF ₃ SO ₃ ) _{2 and the} like. Such a protonic acid salt can be blended in an amount of, for example, about 0.1 to 5 parts by weight with respect to the polyether ester amide (d). Examples of the composition include polyether ester amide mixed with fibers having affinity therefor, for example, polyamide fibers.

  An appropriate blending ratio of the potassium ionomer and the thermoplastic polymer as described above in the adhesive layer is 10 to 100 parts by weight, preferably 50 to 100 parts by weight, more preferably 100 parts by weight of potassium ionomer. The ratio of the thermoplastic polymer to 90 to 100 parts by weight is desirably 90 to 0 parts by weight, preferably 50 to 0 parts by weight, more preferably 30 to 0 parts by weight.

  The adhesive layer can also be blended with a polyhydroxy compound having two or more alcoholic hydroxyl groups in order to improve non-chargeability. Specifically, polyethylene glycol of various molecular weights, polypropylene glycol, polyoxyalkylene glycols such as polyoxyethylene / polyoxypropylene glycol, polyhydric alcohols such as glycerin, hexanetriol, pentaerythritol, sorbitol, and ethylene oxide adducts thereof, Examples include adducts of polyvalent amines and alkylene oxides. The blending ratio of the polyhydroxy compound is 15% by weight or less, preferably 10% by weight or less, more preferably less than 5% by weight, most preferably less than 0.1% by weight based on the potassium ionomer.

In the laminate of the present invention, a polyolefin sealant layer is further provided adjacent to the adhesive layer provided adjacent to the base material layer. The polyolefin-based sealant is selected from olefin homopolymers, copolymers of olefins, copolymers of olefins and polar monomers, or compositions thereof, and is usually in the temperature range of 80 to 250 ° C. It is a heat sealable material. Specifically, a homopolymer of ethylene or a copolymer of ethylene and an α-olefin having 3 to 12 carbon atoms, such as high-pressure polyethylene, medium / high-density polyethylene, linear low-density polyethylene, especially density of 940 kg / M ³ or less linear low density polyethylene, ultra low density polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, copolymer of ethylene and polar monomer, for example, ethylene / vinyl acetate Copolymer, copolymer of ethylene and unsaturated carboxylic acid such as acrylic acid, methacrylic acid, monoethyl maleate, maleic anhydride or the like, or an ionomer such as Na, Li, Zn, Mg or Ca, ethylene and one kind Or two or more unsaturated carboxylic esters such as methyl acrylate, ethyl acrylate, acrylic Copolymer of isobutyl, n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, glycidyl methacrylate, dimethyl maleate, etc., copolymer of ethylene with unsaturated carboxylic acid and unsaturated carboxylic acid ester as above Examples include polymers or their ionomers such as Na, Li, Zn, Mg or Ca, copolymers of ethylene and carbon monoxide and optionally unsaturated carboxylic acid esters or vinyl acetate, or mixtures of two or more of these. be able to.

  Among such polyolefin-based sealants, particularly low density polyethylene, metallocene polyethylene, ethylene / vinyl acetate copolymer, ethylene / unsaturated carboxylic acid copolymer or ionomer thereof, and ethylene / unsaturated carboxylic acid ester copolymer. Use of one or more selected ethylene polymers is preferred because a laminate having good interlayer adhesion with the adhesive layer, excellent heat sealing, and excellent stain resistance can be easily obtained. These ethylene polymers can also be used by blending a low crystalline or amorphous ethylene / α-olefin copolymer or a tackifier resin.

The low-density polyethylene has a density obtained by copolymerizing ethylene and an α-olefin having 3 or more carbon atoms by a high-pressure method polyethylene having a density of 910 to 930 kg / m ³ obtained by a high-pressure method and a medium / low-pressure method. It is a linear low density polyethylene of ˜940 kg / m ³ , preferably 900 to 940 kg / m ³ . Examples of the α-olefin having 3 or more carbon atoms to be copolymerized with ethylene in the linear low density polyethylene include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 4 -Methyl-1-pentene can be exemplified, but an α-olefin copolymer having about 4 to 12 carbon atoms is preferably used.

The metallocene polyethylene suitable as a polyolefin-based sealant means a homopolymer of ethylene or a copolymer of ethylene and an α-olefin having 3 or more, preferably 4 to 12 carbon atoms, produced in the presence of a metallocene catalyst. And partly includes those belonging to the category of linear low-density polyethylene. The metallocene polyethylene has at least one ligand having a cyclopentadienyl skeleton, a catalyst component composed of a transition metal of group IVB of the periodic table, preferably a compound of zirconium, an organoaluminum oxy compound catalyst component, and various kinds as required. It is produced by polymerizing or copolymerizing ethylene in the presence of a catalyst formed from an additive component.

As the metallocene polyethylene, those having various densities can be used depending on the α-olefin content in the copolymer. Generally, the density is about 870 to 970 kg / m ³ , particularly 890 to 950 kg / m ³ , especially 900. It is preferable to use an ethylene copolymer of ˜940 kg / m ³ .

  The ethylene / vinyl acetate copolymer suitable as a polyolefin-based sealant can be obtained by radical copolymerization of ethylene and vinyl acetate under high temperature and high pressure, and has a vinyl acetate content of 2 to 45% by weight, particularly 5 to 5%. 25% by weight is preferred. The ethylene / vinyl acetate copolymer may also be copolymerized with another polar monomer such as carbon monoxide.

  The above-mentioned ethylene / unsaturated carboxylic acid copolymer suitable as a polyolefin-based sealant may be optionally copolymerized with other polar monomers. Ethylene and unsaturated carboxylic acid under high temperature and high pressure, optionally other polar The monomer can be obtained by radical copolymerization. The ionomer of the ethylene / unsaturated carboxylic acid copolymer is obtained by partially neutralizing the copolymer with a metal ion such as sodium, lithium, zinc, magnesium, etc. The sum is preferred.

  Examples of the unsaturated carboxylic acid in the ethylene / unsaturated carboxylic acid copolymer include acrylic acid, methacrylic acid, fumaric acid, maleic anhydride, monomethyl maleate, monoethyl maleate, and the like. Or methacrylic acid is preferable. Examples of polar monomers that can be copolymerized components include vinyl esters such as vinyl acetate and vinyl pyropionate, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, and n-hexyl acrylate. And unsaturated carboxylic acid esters such as isooctyl acrylate, methyl methacrylate, dimethyl maleate and diethyl maleate, carbon monoxide, and the like, and in particular, unsaturated carboxylic acid esters are suitable copolymerization components.

  The ethylene / unsaturated carboxylic acid copolymer preferably has an unsaturated carboxylic acid content of 1 to 25% by weight, particularly about 5 to 20% by weight, and may optionally be copolymerized with a polar monomer. Is, for example, a ratio of 40% by weight or less, preferably 30% by weight or less. The ionomer of the ethylene / unsaturated carboxylic acid copolymer preferably has a neutralization degree of 90% or less, particularly 80% or less.

  The above-mentioned ethylene / unsaturated carboxylic acid ester copolymer suitable as a polyolefin-based sealant can be obtained by radical copolymerization of ethylene and an unsaturated carboxylic acid ester under high temperature and high pressure, and has an unsaturated carboxylic acid content of 2 It is preferred that it is ˜45% by weight, especially 5 to 25% by weight. The ethylene / unsaturated carboxylic acid ester copolymer may also be copolymerized with other polar monomers such as carbon monoxide.

  Ethylene-based selected from the above-mentioned low density polyethylene, metallocene polyethylene, ethylene / vinyl acetate copolymer, ethylene / unsaturated carboxylic acid copolymer or its ionomer and ethylene / unsaturated carboxylic acid ester copolymer suitable as polyolefin-based sealants In consideration of processability, heat seal characteristics, etc., a polymer having a melt flow rate of 0.1 to 100 g / 10 min at 190 ° C. and 2160 g load, particularly 0.2 to 50 g / 10 min is used. Is preferred.

  The laminate of the present invention can be produced by laminating each layer, preferably by extrusion coating, coextrusion or blow molding. For example, when an ethylene / vinyl alcohol copolymer is used as the base material layer, a laminate can be obtained by three-layer coextrusion, and an adhesive layer and a polyolefin-based sealant layer can be formed on the ethylene / vinyl alcohol copolymer film. Can be coextruded or sequentially laminated to obtain a laminate. When polyester is used as the base material layer, it is preferable to use a biaxially stretched film in consideration of gas barrier properties. An adhesive layer and a polyolefin sealant layer are coextruded and laminated on a biaxially stretched film produced in advance. Alternatively, it is preferable to obtain a laminate by sequentially laminating. When a preformed film is used as the base material layer, a surface treatment such as corona treatment can be arbitrarily applied to the adhesive surface in order to improve interlayer adhesion with the adhesive layer.

  Although the total layer thickness of the laminate is arbitrary, it is preferable that the thickness is, for example, about 10 to 3000 μm, particularly about 20 to 1000 μm. In the laminate of the present invention, at least one surface layer of the base material layer and the sealant layer is subjected to 10% decay time (time until decay to +500 V) at an applied voltage of +5000 V measured in an atmosphere of 23 ° C. and 50% relative humidity. ) Is 1 second or less. The adhesive strength between each surface layer and the adhesive layer is at least 2 N / 15 mm or more, preferably 3 N / 15 mm or more. For this purpose, the thickness of the adhesive layer is preferably 5 μm or more, preferably 10 μm or more, and the thickness on the surface layer side having the above attenuation characteristics is preferably 500 μm or less, particularly 300 μm or less. In consideration of practical performance, the thickness ratio of the surface layer to the adhesive layer thickness is preferably in the range of 0.1 to 100, particularly 0.3 to 50.

  Various additives can be blended in each layer as necessary. Examples of such additives include antioxidants, light stabilizers, ultraviolet absorbers, pigments, dyes, lubricants, antiblocking agents, inorganic fillers, foaming agents, and the like. For example, as a foaming agent, an organic or inorganic chemical foaming agent such as azodicarboxamide, dinitrosopentamethylenediamine, sulfonylhydrazide, sodium bicarbonate, ammonium bicarbonate, and 100 parts by weight of a polymer component constituting the layer It can mix | blend in the ratio of about 0.1-10 weight part.

  Hereinafter, the present invention will be described in more detail with reference to examples. In addition, the raw material used in the Example and the comparative example and the physical-property evaluation method are as follows.

1. Raw materials used (1) Base material layer EVOH: Ethylene-vinyl alcohol copolymer (vinyl alcohol content 68 mol%, manufactured by Kuraray Co., Ltd.)

(2) Adhesive layer KIO-1: Potassium ionomer of ethylene / methacrylic acid copolymer having a methacrylic acid content of 12.7% by weight (degree of neutralization 80%, MFR (melt flow rate, 190 ° C., 2160 g load) 0.36 g / 10 minutes)
KIO-2: 80 parts by weight of KIO-1 and 20 parts by weight of maleic anhydride-modified linear low density polyethylene (trade name: Admer NF528, MFR (190 ° C., 2160 g load): 2.3 g / 10 min, Mitsui Chemicals) KIO-3: 80 parts by weight of KIO-1 and 20 parts by weight of the following polyetheresteramide composition-1 Polyetheresteramide composition-1
10 parts by weight of polyetheresteramide (trade name: Irgastat P16, melting point (DSC) 158 ° C., manufactured by Ciba Specialty Chemicals Co., Ltd.) and a polyetheresteramide composition (trade name: Irgastat P18, melting point (DSC) ) Composition comprising 10 parts by weight of 173 ° C. (other endothermic peaks at 153 ° C. and 166 ° C.), containing 5% or less of sodium perchlorate monohydrate, manufactured by Ciba Specialty Chemicals KIO-4 : 80 parts by weight of KIO-1 and 20 parts by weight of EEA (ethylene-ethyl acrylate copolymer, ethyl acrylate content: 9% by weight, MFR (190 ° C., 2160 g load): 5 g / 10 min) AD-1: Zinc ionomer of an ethylene / methacrylic acid copolymer having a methacrylic acid content of 15% by weight (neutralization degree 59%, MF (190 ℃, 2160g load) 0.9g / 10 minutes)
AD-2: Propylene / ethylene random copolymer (trade name: F232DC, MFR (230 ° C., 2160 g load): 2.0 g / 10 min, manufactured by Mitsui Chemicals, Inc.)
AD-3: mPE below

(3) Polyolefin sealant layer mPE: metallocene polyethylene (trade name: Evolue SP2520, density 925 kg / m ³ , MFR (190 ° C., 2160 g load): 1.9 g / 10 min, melting point 122 ° C., manufactured by Mitsui Chemicals, Inc. )

2. Physical property test method (1) Adhesive strength The adhesive strength between the layers of the three-layer film obtained in the examples described later was measured by 180-degree peeling.

(2) Decay time After leaving the three-layer film obtained in the following examples in an atmosphere of 23 ° C. and 50% relative humidity for 24 hours, the EVOH surface and the sealant surface were applied with a static decay meter model 4060 manufactured by ETS USA. The decay time from + 5000V to + 500V was measured as 10% decay time.

[Example 1]
Using the above-mentioned EVOH 50 μm film as the base layer material, the above-mentioned KIO-1 100 μm film as the adhesive layer material, and the above-mentioned mPE 100 μm film as the sealant layer material, respectively, are superposed in this order, A three-layer laminated film was produced by bonding under conditions of 180 ° C., 0.2 MPa, and 5 seconds. The adhesive strength between each layer of this laminated film and the decay time of each surface were measured.

[Examples 2 to 4, Comparative Examples 1 to 3]
In Example 1, a three-layer laminated film was prepared in the same manner except that the adhesive layer material shown in Table 1 was used instead of KIO-1, and the evaluation was performed. The results are also shown in Table 1.

＊：材料破壊

*: Material destruction

Claims (3)

  A base layer composed of an ethylene / vinyl alcohol copolymer, an adhesive layer and a polyolefin-based sealant layer are laminated in this order, and the adhesive layer is an ethylene / unsaturated carboxylic acid copolymer potassium ionomer or It is composed of the composition, and the adhesive strength between the base material layer and the adhesive layer and the adhesive strength between the adhesive layer and the sealant layer are both 2 N / 15 mm or more, and an applied voltage of 5000 V is applied to at least one surface of the base material layer and the sealant layer. A laminate having a 10% decay time of 1 second or less. The laminate according to claim 1 , wherein the adhesive layer is composed of 100 to 70 parts by weight of potassium ionomer and 0 to 30 parts by weight of polyolefin resin (100 parts by weight in total). The polyolefin-based sealant layer is selected from the group consisting of low-density polyethylene, metallocene polyethylene, ethylene / vinyl acetate copolymer, ethylene / unsaturated carboxylic acid copolymer or its ionomer, and ethylene / unsaturated carboxylic acid ester copolymer. The laminate according to claim 1 or 2 , which is a layer composed of an ethylene-based polymer.