JP2009172824A - Laminated body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated body having an aluminum foil layer with excellent gas barrier property, in particular, used as various packing materials, keeping initial excellent laminate strength even when used for packing a highly penetrating substance including agents like perfume, fomentation or a bathing agent, a volatile substance like an organic solvent including alcohol, a surfactant, an acidic substance or an alkaline substance, and causing no lowering of the lamination strength between layers. <P>SOLUTION: A hot water denatured layer is formed at least on one face of the aluminum foil layer by hot water denaturing treatment. An anchor coat layer, an adhesive resin layer, an anchor coat layer and a plastic base material layer are at least layered in this relative order on the hot water denatured layer, and the anchor coat layer is composed of an anchor coat agent containing 85 wt.% or more of a compound having two or more isocyanate groups. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is a laminate having an aluminum foil layer excellent in gas barrier properties and the like, and particularly used as various packaging materials, such as fragrances, poultices and bathing agents, and organic solvents including alcohols, etc. Even if a strong permeable material containing volatile materials, surfactants, acidic materials, alkaline materials, etc. is packaged, the original excellent laminate strength is maintained and the laminate strength between each layer is not lowered. It is about the body.

  Conventionally, as a packaging material having an aluminum foil layer, which is used for packaging foods and pharmaceuticals, for example, polyester layer / adhesive layer / aluminum foil layer / adhesive layer / polyester layer / anchor coat layer / sealant Laminates having a layer structure such as layers are widely used, and various packages are thus produced. Lamination of such a laminated structure is usually performed by dry lamination using a two-component curable polyurethane adhesive, and the anchor coat layer is formed by extrusion lamination. And such a laminated body has moderate lamination strength, gas barrier property, etc., and is suitably used as a packaging material for packaging foods and pharmaceuticals.

  However, the laminating structure as described above is composed of chemicals such as fragrances, poultices, bathing agents, and volatile substances such as alcohol and other organic solvents, surfactants, acidic substances, alkaline substances and the like. When packaged using a package manufactured by the body, the strong penetrating substance passes through the sealant layer located on the innermost layer side of the package due to its very strong penetrating force and reaches the anchor coat layer, As a result, the resin component of the anchor coat layer is swollen and the molecular weight is lowered, the cohesive force is lowered, and delamination (peeling) may occur.

  In order to cope with such a situation, various studies have been made to improve the laminate strength between the layers in the laminate used for the packaging material. Among them, there is a laminate in which at least an adhesive layer (anchor coat layer) and a sealant layer are provided in this order on a plastic substrate layer, and the adhesive layer (anchor coat layer) is made of an isocyanate compound (Patent Document) 1). This laminated body is widely used as a laminated material for packaging because the laminate strength between the layers hardly decreases even when the above-described strong penetrating substance acts.

However, some strong penetrating substances including fragrances, poultices, bathing agents, volatile substances such as alcohol and other organic solvents, surfactants, acidic substances, alkaline substances, etc. Due to its extremely strong penetrating power, it passes through the innermost sealant layer, anchor coat layer, and polyester layer of the laminate and stays between the aluminum foil layer / adhesive layer, causing swelling of the resin component of the adhesive layer and molecular weight reduction. In some cases, the cohesive force was reduced and delamination occurred.
JP 2005-335374 A

The present invention has been made in order to solve the above-mentioned problems, and the object of the present invention is a laminate having an aluminum foil layer excellent in gas barrier properties and the like. Used as a fragrance, poultice, bathing agent, etc., and volatile substances such as alcohol and other organic solvents, strong penetrating substances including surfactants, acidic substances, alkaline substances, etc. Even so, an object of the present invention is to provide a laminate that is excellent in the laminate strength between the layers so as to maintain the original excellent laminate strength.

  In order to solve the above problems, the invention according to claim 1 is characterized in that a hot water denaturation treatment layer is formed on at least one surface of the aluminum foil layer by a hydrothermal denaturation treatment. On the layer, at least an anchor coat layer, an adhesive resin layer, an anchor coat layer, and a plastic substrate layer are laminated in this relative order, and the anchor coat layer contains 85 compounds having two or more isocyanate groups. A laminate comprising an anchor coating agent contained in an amount of not less than% by weight.

  The invention according to claim 2 is the laminate according to claim 1, wherein the compound having two or more isocyanate groups is a bifunctional isocyanate monomer, or a trifunctional type of adduct, burette, or isocyanurate type. It is characterized by being a derivative of any of the above monomers.

  Furthermore, the invention according to claim 3 is the laminate according to claim 1 or 2, wherein the hydrothermal modification layer is formed by boehmite treatment.

  Furthermore, the invention according to claim 4 is the laminate according to claim 1 or 3, wherein the adhesive resin layer is made of either a polyethylene resin or a polypropylene resin. .

  In the laminate of the present invention, a hot water modification treatment layer is formed on at least one surface of the aluminum foil layer by a hot water modification treatment, and an anchor coat layer and an adhesive resin are formed on the hot water modification treatment layer. The anchor coat layer and the anchor base layer are laminated at least in this relative order, and the anchor coat layer is composed of an anchor coat agent containing 85% by weight or more of a compound having two or more isocyanate groups. Has been. Therefore, the anchor coat layer laminated on both sides of the adhesive resin layer is a strong material containing volatile substances such as fragrances, medicinal ingredients, alcohol and other organic solvents, surfactants, acidic substances, alkaline substances and the like. Since it is difficult to be affected by the osmotic substance, even if the strong osmotic substance as described above acts, the excellent laminate strength originally possessed does not decrease and delamination does not occur.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a schematic cross-sectional configuration of a laminate according to the present invention. In this laminate, a hot water denaturation treatment layer 4 is formed on at least one surface of the aluminum foil layer 3 by a hydrothermal denaturation treatment, and the anchor coat layer 5 is adhered on the hot water denaturation treatment layer 4. The resin layer 6, the anchor coat layer 7 and the plastic substrate layer 8 are laminated at least in this relative order, and the anchor coat layers 5 and 7 contain 85% by weight or more of a compound having two or more isocyanate groups. It is comprised with the anchor coat agent formed.

  FIG. 1 shows an example in which an anchor coat layer 9 and a sealant layer 10 are further laminated on the plastic substrate layer 8 described above. Reference numeral 15 denotes an aluminum foil laminated base material in which the aluminum foil layer 3 on which the hydrothermal modification layer 4 is formed is laminated via an adhesive layer.

  The aluminum foil layer 3 constituting the laminate of the present invention is subjected to hydrothermal modification treatment for improving adhesion on the surface in contact with the anchor coat layer 5 described later, so that the hydrothermal modification treatment layer 4 is formed.

  Examples of the treated water used when hydrothermally transforming the surface of the aluminum foil include tap water, deionized water, distilled water, and distilled water distilled after deionization. Among them, deionized distilled water is preferably used, and in particular, those having an electric conductivity of 1 μs / cm or less are preferably used. In addition, it is recommended to add a small amount of alkali such as amines such as ammonia and triethanolamine to these treated waters in an amount of about 0.1 to 1% by weight to perform the hydrothermal conversion treatment.

  In the hydrothermal modification treatment on the aluminum foil surface, various hydrous oxide films are coated on the surface depending on the treatment temperature to form a hydrothermal modification treatment layer. The formed hydrothermal modification layer 4 is composed of a boehmite film obtained by performing boehmite treatment (hydrothermal modification treatment) in the range of about 80 to 100 ° C., more preferably about 90 to 100 ° C. under normal pressure. Those are preferred.

  On the other hand, the anchor coat layers 5 and 7 have a thickness of about 1 μm or less and are composed of an anchor coat agent containing 85% by weight or more of a compound containing two or more isocyanate groups. In this anchor coating agent, a compound having a good compatibility with an isocyanate compound is mixed in an amount of not more than 15% by weight, not a compound that is too reactive with an isocyanate group and gels immediately. May be. Specifically, in addition to polyester polyol, polyether polyol, and acrylic polyol, polyester polyurethane polyol, polyether polyurethane polyol, and the like based on these may be mixed.

  Examples of the compound having two or more isocyanate groups contained in the anchor coat agent constituting the anchor coat layers 5 and 7 include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, and xylylene diene. Specific examples thereof include various diisocyanate monomers such as isocyanate, isophorone diisocyanate, hexamethylene diisocyanate, 4,4′-diphenylmethane diisocyanate and hydrogenated products thereof. In addition, adduct types obtained by reacting these diisocyanate monomers with trifunctional active hydrogen-containing compounds such as trimethylolpropane and glycerol, burette types obtained by reacting with water, and trimers utilizing self-polymerization of isocyanate groups ( A trifunctional derivative such as an isocyanurate type or a polyfunctional derivative higher than that may be used.

  When the anchor coat layer is formed by using, for example, a polyester polyol-rich anchor coat agent comprising 90% by weight of the polyester polyol and 10% by weight of the isocyanate compound, the strongly permeable content as described above is obtained. It exerts an adverse effect and causes the polyester polyol to swell and the molecular weight to decrease, thereby reducing the cohesive force of the anchor coat layer. On the other hand, as the anchor coat layers 5 and 7 constituting the laminate of the present invention, by providing an anchor coating agent rich in an isocyanate compound so that the laminate strength between the respective layers does not decrease with time, That is, the anchor coat agent constituting the anchor coat layers 5 and 7 contains 85 wt% or more, more preferably 90 wt% or more, of an isocyanate compound having two or more isocyanate groups. The coat layer is not affected by the strongly permeable contents. Further, each of the anchor coat layer 5 and the anchor coat layer 7 is an anchor coat agent having the same composition as long as it is composed of an anchor coat agent containing 85% by weight or more of a compound having two or more isocyanate groups. Even if comprised, it may be comprised by the anchor coat agent of a different composition.

The anchor coat layers 5 and 7 having such a structure have a solid content ratio of 0.05 to 5% by weight, preferably a compound or a compound containing 85% by weight or more of a compound having two or more isocyanate groups, preferably An anchor coating agent contained at a ratio of 0.1 to 2% by weight may be used and coated. Further, the anchor coat layers 5 and 7 are preferably thin, and specifically, the anchor coat layers 5 and 7 may be provided so as to be a thin layer having a thickness of about 1 μm or less when dried. If it exceeds 1 μm, it takes time to dry the solvent of the anchor coating agent that forms the anchor coating layer, and the thin film made of the anchor coating agent is insufficiently dried. It may disappear unexpectedly.

  The anchor coat layer 9 has the same structure as the anchor coat layers 5 and 7 described above.

  The adhesive resin layer 6 is a layer made of an adhesive resin such as a polyethylene resin or a polypropylene resin. Adhesive resins include ethylene resins such as high-density polyethylene, low-density polyethylene, medium-density polyethylene, and ethylene-α olefin copolymers, homo-block / random polypropylene resins, and propylene-α-olefin copolymers. Propylene resins such as ethylene-acrylic acid copolymers and ethylene-methacrylic acid copolymers, such as ethylene-α, β-unsaturated carboxylic acid copolymers, ethylene-methyl acrylate, ethylene-ethyl acrylate, ethylene- Esterified products of ethylene-α, β unsaturated carboxylic acid copolymers such as methyl methacrylate and ethylene-ethyl methacrylate, and ethylene-α, β unsaturated carboxylic acid copolymers obtained by crosslinking carboxylic acid sites with sodium ions and zinc ions. Polymer ionic crosslink, ethylene-maleic anhydride graft copolymer And anhydride-modified polyolefins typified by terpolymers such as ethylene-ethyl acrylate-maleic anhydride, epoxy compound-modified polyolefins such as ethylene-glycidyl methacrylate copolymers, and ethylene-vinyl acetate copolymers Or a blend of two or more kinds of resins selected from: Various additives (such as antioxidants, tackifiers, fillers, and various fillers) may be added to these constituent materials as necessary.

  As the plastic base layer 8, various types such as a polyester film normal type, a copolymer type or an easy adhesion type, and a nylon film normal type or an easy adhesion type can be used. is there.

  The base material of the plastic base material layer 8 is such that the surface on which the anchor coat layer 7 is formed is subjected to surface treatment such as corona treatment, and the anchor coat layer 7 can be stably formed thereon. Any type of plastic substrate can be used. Further, the thickness is not particularly limited.

  The laminated body according to the present invention has been described above, but the laminated body of the present invention is not limited to the structure as described above, and the rigidity required as a packaging material in consideration of the use as a packaging material. In addition, for the purpose of improving durability and the like, a structure in which another layer is interposed may be used.

More specific examples of the configuration in which another layer is interposed include those shown in [Configuration 1] and [Configuration 2] below.
[Configuration 1]
Polyethylene terephthalate (PET) layer / adhesive layer / aluminum foil layer (boehmite treated layer) / anchor coat layer A / adhesive resin layer / anchor coat layer B / PET film (plastic base layer) / anchor coat layer C / sealant layer [Configuration 2]
PET layer / adhesive layer / aluminum foil layer (boehmite treatment) / anchor coat layer A / sand resin layer / anchor coat layer B / nylon film (plastic substrate layer) / anchor coat layer C / sealant layer 1] and [Configuration 2] An example of a method for manufacturing a stacked body having the configuration will be described.

  In preparation of the laminate according to Configuration 1, first, an aluminum foil is laminated on a polyethylene terephthalate (PET) film, which is the outermost layer, by dry lamination using a two-component curable urethane adhesive, and then the surface of the aluminum foil Boehmite treatment. Next, the anchor coat layer A is provided on the boehmite-treated surface of the aluminum foil layer using a tandem extrusion laminator. On the other hand, a laminate comprising an anchor coat layer B provided on one side of a separately prepared PET film is prepared, and the anchor coat layer B of this laminate is opposed to the anchor coat layer A so that the first Sandwich lamination is performed while supplying adhesive resin from an extruder. Immediately thereafter, the sealant layer is extruded and laminated with a second extruder while the anchor coat layer C is provided on the surface of the PET film of the laminate to produce the laminate of the invention according to Configuration 1. The anchor coat layers A, B, and C are composed of a compound or a mixture of a compound containing 85% by weight or more of a compound having two or more isocyanate groups in a solid content ratio of 0.05 to 5% by weight, preferably 0.1 to 0.1%. An anchor coating agent contained at a ratio of 2% by weight is used, and it may be provided by coating at the coating part of the extrusion laminate so that the thickness thereof is about 1 μm or less.

  In addition, what is necessary is just to produce the laminated body which concerns on the structure 2 by replacing the PET film of the laminated body which concerns on the structure 1 with a nylon film.

  According to the production method as described above, the initial laminate strength is good in all layers including the aluminum foil layer, and volatile substances such as fragrances, medicinal ingredients and alcohols, surfactants, acidic Even when a strongly permeable content containing a substance, an alkaline substance, or the like acts, it is possible to produce a laminate that maintains the excellent laminate strength originally possessed between the layers.

  Hereinafter, preferred embodiments of the present invention will be described.

  First, a polyethylene terephthalate (PET) film having a thickness of 12 μm and an aluminum foil having a thickness of 7 μm are dry-laminated using a two-component curable urethane adhesive, and a laminated substrate made of PET film / adhesive layer / aluminum foil layer Was made. Next, boiling (about 95 ° C.) deionized distilled water adjusted to pH 7 to 9 is stored in a treatment tank, and inline boehmite treatment (immersion time 3) is applied to the aluminum foil surface of the laminated base material obtained in the above step. Min). Next, using a tandem extrusion laminator, the adduct type of tolylene diisocyanate is contained on the boehmite-treated surface of the laminated base material having a laminated structure of PET film / adhesive layer / aluminum foil layer (boehmite-treated layer), and solid An anchor coat layer A is formed using an anchor coating agent having a fraction of 2% by weight, and at the same time, an anchor coat layer B is formed on the PET film while flowing a PET film serving as a plastic substrate layer from the film supply mechanism. Is formed in the same manner as the anchor coat layer A, and a 15 μm thick low-density polyethylene layer made of an adhesive resin is formed from the first extruder with the anchor coat layer A at a die lower temperature of 320 ° C. and a processing speed of 80 m / min. It was supplied between the anchor coat layers B and sandwich-laminated. Immediately thereafter, a sealant layer made of low-density polyethylene having a thickness of 40 μm was formed by a second extruder while forming an anchor coat layer C on the laminated laminate PET film in the same manner as the anchor coat layer A. Extrusion was performed at a temperature below the die of 320 ° C. and a processing speed of 80 m / min to obtain a laminate according to Example 1. The thicknesses of the anchor coat layers A, B, and C after drying were 0.21, 0.24, and 0.22 μm, respectively.

  Example 2 is the same as Example 1 except that an anchor coat agent containing an adduct type of xylylene diisocyanate is used instead of the constituent materials of anchor coat layers A, B, and C according to Example 1. Such a laminate of the present invention was obtained. The thicknesses after drying of anchor coat A2 (corresponding to anchor coat layer A), B2 (corresponding to anchor coat layer B), and C2 (corresponding to anchor coat layer C) are 0.25, 0.23, and 0.22 μm, respectively. Met.

  Instead of the constituent materials of the anchor coat layers A, B, and C according to Example 1, an anchor coat agent in which the adduct type of hexamethylene diisocyanate and the polyester polyol are mixed at a weight ratio of 90:10 is used. The present invention according to Example 3 is the same as Example 1 except that a nylon film having a thickness of 15 μm is used as the plastic substrate layer, and an ethylene-methacrylic acid copolymer is used as the sealant layer. A laminate was obtained. The thicknesses after drying of the anchor coat A3 (corresponding to the anchor coat layer A), B3 (corresponding to the anchor coat layer B), and C3 (corresponding to the anchor coat layer C) are 0.22, 0.25, and 0.22 μm, respectively. Met. The under-die temperature at the time of forming the sealant layer was 280 ° C.

  Instead of the constituent materials of the anchor coat layers A, B, and C according to Example 1, the isocyanurate type of hexamethylene diisocyanate and the polyether polyol are mixed so that the weight ratio is 85:15, and an anchor coat agent is used. Moreover, random polypropylene was used as the constituent material of the adhesive resin layer, and a nylon film having a thickness of 15 μm was used as the plastic substrate layer, and random polypropylene was used as the constituent material of the sealant layer. By the method, the laminate of the present invention according to Example 4 was obtained. The thicknesses after drying of anchor coat A4 (corresponding to anchor coat layer A), B4 (corresponding to anchor coat layer B), and C4 (corresponding to anchor coat layer C) are 0.26, 0.25, and 0.24 μm, respectively. Met. The under-die temperature at the time of forming the sealant layer was 280 ° C.

  After dry laminating a PET film with a thickness of 12 μm and an aluminum foil with a thickness of 7 μm using a two-component curable urethane adhesive, a two-component curable urethane adhesive is used on the aluminum foil layer of the obtained laminated base material. A PET film was dry laminated to obtain a laminated substrate. Next, after forming an anchor coat layer on the PET film of the laminated base material with an anchor coating agent having an adduct type solid content ratio of tolylene diisocyanate of 2% by weight, a low density of 40 μm in thickness is further formed thereon. The polyethylene layer was extruded at a temperature under the die of 320 ° C. and a processing speed of 80 m / min to laminate a sealant layer, and a laminate according to Example 5 for comparison was obtained. The thickness of the anchor coat layer after drying was 0.23 μm.

  An anchor coat in which a nylon film with a thickness of 15 μm is used as the plastic base layer, and an adduct type of xylylene diisocyanate and a polyester polyol are mixed at a weight ratio of 75:25 as the anchor coat agent constituting the anchor coat layer. A laminate according to Example 6 for comparison was obtained in the same manner as in Example 5 except that an ethylene-methacrylic acid copolymer was used as a sealant agent further constituting the sealant layer. . The thickness of the anchor coat layer after drying was 0.24 μm, and the temperature under the die when forming the anchor coat layer was 280 ° C.

After performing aging at 50 ° C. for 3 days for each of the laminates of Examples 1 to 6 obtained as described above, two pouches were produced using each laminate, and each pouch was Limonene diluted to 5 wt% with ethyl acetate and 1-menthol diluted to 5 wt% with ethyl acetate as a strong osmotic content were filled, sealed, and left in a constant temperature room at 40 ° C.

  After 3 months, these pouches were taken out of the temperature-controlled room, and the laminate strength [N / 15 mm] between the aluminum foil layer / plastic base layer and the plastic base layer / sealant layer of each pouch was measured. It was compared with the initial laminate strength in the pouch before putting. The measurement conditions of the laminate strength at this time were T-type peeling with a sample width of 15 mm and a peeling speed of 300 mm / min. Tables 1 and 2 summarize the measurement results of the laminate strength before and after the constant temperature input.

As is clear from Tables 1 and 2, the initial laminate strength between the plastic substrate layer and the sealant layer of the laminates of the present invention according to Examples 1 to 4 was so strong that the resin was cut. In addition, in the pouch stored with limonene solution or l-menthol solution at 40 ° C. for 3 months, there was no change in the laminate strength between the aluminum foil layer / plastic substrate layer and between the plastic substrate layer / sealant layer. The laminate strength was kept sufficiently.

  On the other hand, in the laminate for comparison according to Examples 5 to 6, the initial laminate strength between the aluminum foil layer / plastic base layer and the plastic base layer / sealant layer was sufficiently obtained, In a pouch stored with limonene solution or l-menthol solution at 40 ° C. for 3 months, the laminate according to Example 5 was affected by the strong permeability of limonene solution and l-menthol, and the aluminum foil layer / plastic The laminate strength between the substrate layers was significantly reduced. In addition, in the laminate according to Example 6, a significant decrease in the strength of the laminate strength was observed both in the aluminum foil layer / plastic base layer and in the plastic base layer / sealant layer, which is not suitable for use in packaging materials. There was found.

It is explanatory drawing which shows the schematic cross-sectional structure of the laminated body of this invention.

Explanation of symbols

1. · Plastic substrate 2 ·· Adhesive layer 3 ·· Aluminum foil layer 4 ·· Hydrothermally modified layers 5, 7, 9 ·· Anchor coat layer 6 ·· Adhesive resin layer 8 ·· Plastic substrate layer 10 ..Sealant layer 15

Claims (4)

  A hydrothermal modification layer is formed on at least one surface of the aluminum foil layer by hydrothermal modification treatment, and an anchor coat layer, an adhesive resin layer, an anchor coat layer, and a plastic are formed on the hydrothermal modification treatment layer. The base material layer is at least laminated in this relative order, and the anchor coat layer is composed of an anchor coat agent containing 85% by weight or more of a compound having two or more isocyanate groups. body.   2. The compound according to claim 1, wherein the compound having two or more isocyanate groups is a bifunctional isocyanate monomer or a derivative of a trifunctional monomer of adduct, burette, or isocyanurate type. Laminated body.   The laminate according to claim 1 or 2, wherein the hydrothermal modification layer is formed by boehmite treatment.   The said adhesive resin layer consists of either a polyethylene-type resin or a polypropylene-type resin, The laminated body in any one of Claims 1-3 characterized by the above-mentioned.