JP2006187908A - Laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminate constituted by providing at least an adhesive layer and a sealant layer on a base material comprising either one of a polyester, nylon and polypropylene in this order and characterized in that the adhesive layer and the sealant layer have excellent adhesive strength with respect to the base material and the adhesive strength between the base material and the sealant layer is not lowered even if a volatile component or various penetrative contents containing the volatile component act on the laminate. <P>SOLUTION: The adhesive layer 3 comprises a main agent comprising either one of a polyester polyol, a polyether polyol and an acrylic polyol and a curing agent comprising an isocynate compound, wherein the ratio of the main agent and the isocyanate compound is 1:99-15:85. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a laminate in which at least an adhesive layer and a sealant layer are provided in this order on a substrate made of polyester, nylon, or polypropylene, and has excellent laminate strength with respect to those substrates. In addition, the present invention relates to a laminate in which the laminate strength between the base material and the sealant layer does not decrease even when volatile components or various strongly permeable contents containing volatile components act.

  Conventionally, as a packaging material for packaging foods and pharmaceuticals, for example, a laminate in which layers such as paper layer / polyethylene layer / aluminum foil layer / polyester layer / sealant layer are laminated has been widely used. The lamination of the polyester layer and the sealant layer of this laminate is usually performed by applying an anchor coating agent such as a two-component curable polyurethane to a polyester layer made of a polyester film and then extruding the sealant layer. It was. And such a laminated body has moderate lamination strength, gas barrier property, etc., and is widely used as a packaging material for packaging foods and pharmaceuticals.

  However, many of the contents packaged by the packaging material contain an alkaline substance, a fragrance, a surfactant, a high-boiling organic solvent, etc., and when these contents are packaged, an adhesive that constitutes an adhesive layer In some cases, the laminate strength may be lowered or peeling may occur in the laminate.

  In order to cope with this situation, various improvements have been made to the adhesive used for laminating, improving resistance to highly alkaline contents, and further improving adhesion to various plastic films. Various agents have been proposed (see, for example, Patent Document 1).

  However, when the content to be packed is a poultice or a bath preparation, since these contain volatile substances, the laminate having the structure as described above or the laminate obtained using the anchor coating agent is used. Is used as a packaging material, and when these contents are packaged, the laminate strength between the polyester layer and the sealant layer made of polyester film decreases with time due to the strong penetration of volatile substances, resulting in delamination. There was a problem of causing.

  As the adhesive layer used in the laminate, a two-component curable polyurethane system is often used. The usual blending ratio of a curing agent composed of a main component such as polyester polyol and an isocyanate compound is, for example, 95: 5, 90: As shown in Fig. 10, the main agent is used in a larger amount. However, the strongly penetrating contents have an adverse effect on the two-component curable polyurethane adhesive layer obtained at a normal blending ratio, causing swelling of the main resin component and molecular weight reduction, and the cohesive force of the adhesive layer decreases. Therefore, it is considered that the laminate strength between the base material and the sealant layer decreases with time.

On the other hand, in the adhesive layer of the laminate of the present invention, the blending ratio of the curing agent is larger than that of the main agent, and a very thin and dense layer of 1 μm or less is formed. Since the resin component does not swell and the molecular weight does not decrease in the adhesive layer due to the influence of the properties, the laminate strength between the base material and the sealant layer does not decrease and delamination does not occur.
Japanese Patent Laid-Open No. 10-130615

  The present invention has been made in order to solve the above-mentioned conventional problems, and the problem is that at least an adhesive layer and a sealant layer are formed on a base material made of polyester, nylon, or polypropylene. Laminated bodies provided in order have excellent laminate strength with respect to those base materials, and those base materials even when various strongly permeable contents including volatile components and volatile components act And providing a laminate in which the laminate strength between the sealant layers does not decrease.

  In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that at least an adhesive layer and a sealant layer are provided in this order on a base material made of any one of polyester, nylon, and polypropylene. The layer is composed of a main component composed of any one of polyester polyol, polyether polyol, and acrylic polyol and a curing agent composed of an isocyanate compound, and the ratio thereof is 1:99 to 15:85. .

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

  Furthermore, the invention according to claim 3 is the laminate according to claim 1 or 2, wherein the adhesive layer has a thickness of 1 μm or less.

  Furthermore, in the invention according to claim 4, in the laminate according to any one of claims 1 to 3, an easy adhesion treatment layer is formed on at least the surface of the polyester, nylon or polypropylene on the adhesive layer side. It is characterized by that.

  Furthermore, the invention according to claim 5 is the laminate according to claim 4, wherein the easy adhesion treatment layer is subjected to corona treatment, low pressure plasma treatment, atmospheric pressure plasma treatment, and flame treatment. And

  Furthermore, the invention described in claim 6 is characterized in that, in the laminate according to claim 4, the easy adhesion treatment layer is formed by coating a polyester resin or a polyurethane resin.

  Furthermore, the invention according to claim 7 is the laminate according to any one of claims 1 to 6, wherein the sealant layer is made of a polyethylene resin or a polypropylene resin.

  The laminate of the present invention is composed of at least three layers of a base material made of polyester, nylon or polypropylene, an adhesive layer, and a sealant layer, and the adhesive layer is not affected by the strongly permeable content. Since it is made of a thin and dense layer, it exhibits excellent laminate strength with respect to the substrate. Therefore, for example, even when used as a packaging material for storing various strongly permeable contents such as poultices and bathing agents, the laminate strength between the base material and the sealant layer 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 structure of a laminate according to the present invention.

  The laminate 1 is formed by laminating an adhesive layer 3 and a sealant layer 4 in this order on a substrate 2.

  The base material 2 constituting the laminate of the present invention is made of polyester, nylon or polypropylene. More specifically, it is made of any one of a polyester film, a nylon film, and a polypropylene film.

  There are various types of polyester film such as normal type, copolymerized type, and easy-adhesion type, nylon film normal type and easy-adhesion type, and polypropylene film with non-static type and static-proof type. However, surface treatment such as corona treatment, low-pressure plasma treatment, atmospheric pressure plasma treatment, flame treatment, and polyester resin or polyurethane resin coating is applied as an easy-adhesion treatment layer on one of the surfaces. Any type of film can be used as a substrate as long as it can be stably formed. Further, the thickness is not particularly limited.

  The adhesive layer 3 is composed of a layer in which a main agent composed of polyester polyol, polyether polyol, and acrylic polyol and a curing agent composed of an isocyanate compound are mixed. As the main agent constituting the adhesive layer 3, in addition to polyester polyol, polyether polyol and acrylic polyol, polyester polyurethane polyol and polyether polyurethane polyol based on these may be used.

  On the other hand, as an isocyanate compound that is a curing agent constituting the adhesive layer 3, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, 4,4 ′ Specific examples include various diisocyanate monomers such as diphenylmethane diisocyanate and hydrogenated products thereof. In addition, adduct types in which these diisocyanate monomers are reacted with trifunctional active hydrogen-containing compounds such as trimethylolpropane and glycerol, burette types in which they are reacted 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.

  Regarding the ratio of the main agent and the curing agent constituting the adhesive layer 3, for example, when a main agent-rich adhesive layer is formed as in 90:10, the strongly penetrating contents have an adverse effect and the main resin component swells and the molecular weight decreases. In order to reduce the cohesive force of the adhesive layer, the laminate strength between the base material and the sealant layer decreases with time, so that a hardener-rich adhesive layer is formed, that is, the ratio between the main agent and the hardener. Is 1:99 to 15:85, more preferably 1:99 to 10:90, and even more preferably 1:99 to 5:95, thereby obtaining an adhesive layer that is not affected by the strongly permeable content. .

  The adhesive layer 3 is a coating containing, for example, a mixture of the above-mentioned main agent and curing agent on the above-described base material 2 at a solid content ratio of 0.05 to 5 wt%, preferably 0.1 to 2 wt%. What is necessary is just to apply and apply a working liquid. The adhesive layer 3 is preferably a thin layer. Specifically, the adhesive layer 3 may be provided so as to be a thin layer having a thickness of 1 μm or less when dried. When the thickness is 1 μm or more, it takes time for drying to blow off the solvent, and it takes time for the reaction of the adhesive layer, which causes a problem that the development of resistance to strongly permeable contents is delayed.

  On the other hand, the sealant layer 4 provided on the adhesive layer 3 is a layer made of polyethylene resin, polypropylene resin, or the like. Specifically, ethylene resins such as high density polyethylene, low density polyethylene, medium density polyethylene, ethylene-α olefin copolymer, homo-block / random polypropylene resins, propylene-α olefin copolymer, etc. Propylene resin, ethylene-α, β unsaturated carboxylic acid copolymer such as ethylene-acrylic acid copolymer and ethylene-methacrylic acid copolymer, ethylene-methyl acrylate, ethylene-ethyl acrylate, ethylene-methacrylic Ethylene-α, β-unsaturated carboxylic acid copolymers such as methyl methacrylate and ethylene-ethyl methacrylate, ethylene-α, β-unsaturated carboxylic acid copolymer with carboxylic acid moiety cross-linked with sodium ion and zinc ion Ionic cross-linked products of polymers, ethylene-maleic anhydride graft copolymers and polymers Selected from acid anhydride-modified polyolefins typified by terpolymers such as tylene-ethyl acrylate-maleic anhydride, epoxy compound-modified polyolefins such as ethylene-glycidyl methacrylate copolymers, and ethylene-vinyl acetate copolymers It is provided by a single resin or a blend of two or more. You may add various additives (Antioxidant, a tackifier, a filler, various fillers, etc.) to these structural materials as needed.

  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. For the purpose of improving the durability and the like, another layer may be interposed.

  Moreover, the laminated body of such a structure can be produced as follows, for example.

  That is, as one of the production methods, the solid content ratio of the mixture of the main agent and the curing agent is 0.05 to 5 wt%, preferably 0.1 on the surface of the base material that has been subjected to surface treatment such as corona treatment. After coating the coating solution prepared so as to be 2 wt% in the coating part of the extrusion laminate, drying the solvent and providing an adhesive layer, a sealant layer made of, for example, polyethylene or the like is formed on the adhesive layer. A method of obtaining a laminate having a structure of three layers of substrate / adhesive layer / sealant layer by laminating and aging by curing the adhesive layer can be exemplified.

  As another production method, a coating liquid containing a mixture of a main agent and a curing agent in an anchor coating agent coating portion of a coating apparatus immediately after in-line corona treatment on one surface of the above-described base material The surface of the sealant layer made of, for example, polyethylene extruded from the T-die is appropriately subjected to ozone treatment, and then passed through the adhesive layer. The base material and the sealant layer are laminated, and the adhesive layer is cured by aging, whereby the interlayer laminate strength is further improved and a laminate having excellent resistance to various strongly permeable contents can be obtained.

  According to the production method as described above, the laminate strength between various base materials and the sealant layer is good, and even when various strong penetrating contents including volatile substances and volatile substances act, A laminate in which the laminate strength with the sealant layer does not decrease can be produced. Examples of the present invention will be described below.

Using a normal type biaxially stretched polyester film with a thickness of 12 μm with corona treatment on one side as a base material, on the corona treatment side, a polyester polyol as a main agent and an adduct type of tolylene diisocyanate as a curing agent, Low density with a thickness of 40 μm while applying a coating solution prepared so that the solid content ratio of 2% by weight of the main agent: curing agent = 1: 99 is formed, and the solvent is dried to form an adhesive layer. Polyethylene was extruded at a processing speed of 80 m / min by an extrusion laminating method and laminated on the adhesive layer as a sealant layer (thickness: 40 μm), aged at 50 ° C. for 3 days to cure the adhesive layer, and the lamination according to Example 1 Got the body. At this time, the thickness of the adhesive layer after drying was 0.21 μm.

  The same procedure as in Example 1 was conducted except that a coating liquid in which an adduct type of polyester polyol as a main agent and tolylene diisocyanate as a hardener and a main agent: a hardener = 5: 95 was used as an adhesive layer was used. A laminate according to 2 was obtained.

  The same procedure as in Example 1 was used except that a coating liquid in which an adduct type of polyester polyol as a main agent and tolylene diisocyanate as a hardener and a main agent: hardener = 10: 90 was used as an adhesive layer was used. A laminate according to 3 was obtained.

  Using a copolymer type biaxially stretched polyester film with a thickness of 12 μm as a base material and a corona treatment on one surface, immediately after inline corona treatment on the corona treatment surface, a polyester polyol as the main agent as an adhesive layer The adhesive layer is formed by using a coating liquid having a solid content ratio of 2 wt%, in which an adduct type of isophorone diisocyanate is mixed with the curing agent so that the main agent: curing agent = 15: 85, and the adhesive layer is extruded from the T-die. The surface of the low-density polyethylene film having a thickness of 40 μm that is in contact with the adhesive layer is subjected to ozone treatment, and then laminated on the adhesive layer on the substrate formed in the above step at a processing speed of 80 m / min. The adhesive layer was cured by aging for a day to obtain a laminate according to Example 4.

  A normal type biaxially stretched nylon film having a thickness of 15 μm and subjected to corona treatment on one surface as a base material, polyether polyol as a main agent, isophorone diisocyanate monomer as a hardener, main agent: hardener = The laminated body which concerns on Example 5 was obtained by the method similar to Example 1 except having used the coating liquid mixed so that it might be set to 5:95, and using the ethylene-methacrylic acid copolymer as a sealant layer.

  Using a non-static type biaxially stretched polypropylene film with a thickness of 20 μm with corona treatment on one side as a base material, polyester polyol as the main agent and hexamethylene diisocyanate burette type as the curing agent, A laminate according to Example 6 was obtained in the same manner as in Example 1 except that the coating liquid mixed so that the main agent: curing agent = 5: 95 was used and random polypropylene was used as the sealant layer.

  A normal type biaxially stretched polyester film with a thickness of 12 μm, which is subjected to low-pressure plasma treatment on one side as a base material, an acrylic polyol as a main agent and an adduct type of tolylene diisocyanate as a hardener as an adhesive layer. The laminated body which concerns on Example 7 was obtained by the method similar to Example 1 except having used the coating liquid mixed so that it might become hardening agent = 15: 85.

  Using a normal type biaxially stretched nylon film with a thickness of 15 μm that has been subjected to atmospheric pressure plasma treatment on one side as a substrate, acrylic polyol as the main agent and hexamethylene diisocyanate burette type as the curing agent, The laminated body which concerns on Example 8 was obtained by the method similar to Example 1 except having used the coating liquid mixed so that it might become main ingredient: curing agent = 10: 90.

  Using a non-static type biaxially stretched polypropylene film with a thickness of 20 μm as a base material with a frame treatment on one side, a polyester polyol as the main agent and an adduct type of tolylene diisocyanate as the main agent as the adhesive layer : The laminated body which concerns on Example 9 was obtained by the method similar to Example 1 except using the coating liquid mixed so that it might become 5:95, and using random polypropylene as a sealant layer.

  A normal type biaxially stretched polyester film with a thickness of 12μm with a polyurethane resin coat on one side is used as the base material. The main component is an adduct type of polyester polyol as the main agent and xylylene diisocyanate as the curing agent. : The laminated body which concerns on Example 10 was obtained by the method similar to Example 1 except having used the coating liquid mixed so that it might be set to 15:85, and using the zinc ionomer as a sealant layer.

  Using a normal type biaxially stretched nylon film with a polyester resin coat on one side as a base material and a thickness of 15 μm, as an adhesive layer, a polyether polyol as a main agent and an adduct type of xylylene diisocyanate as a curing agent, A laminate according to Example 11 was obtained in the same manner as in Example 1 except that the coating solution mixed so that the main agent: curing agent = 10: 90 was used.

  Uses a normal type biaxially stretched polyester film with a corona treatment on one side as the base material and a thickness of 12μm. Adhesive layer is polyester polyol as the main agent and adduct type of tolylene diisocyanate as the main agent. The laminated body which concerns on Example 12 for a comparison was obtained by the method similar to Example 1 except having used the coating liquid mixed so that it might become agent = 25: 75.

  A normal type biaxially stretched nylon film with a corona treatment on one side and a thickness of 15 μm is used as the base material. The adduct type is polyester polyol as the main agent and isophorone diisocyanate as the hardener as the adhesive layer. = Lamination according to Example 13 for comparison in the same manner as in Example 1 except that the coating liquid mixed so as to be 50:50 was used and an ethylene-methacrylic acid copolymer was used as the sealant layer. Got the body.

  Using a non-static type biaxially stretched polypropylene film with a thickness of 20 μm with corona treatment on one side as a base material, polyester polyol as the main agent and hexamethylene diisocyanate burette type as the curing agent, Laminate according to Example 14 for comparison in the same manner as in Example 1 except that the coating liquid mixed so that the main agent: curing agent = 75: 25 was used and random polypropylene was used as the sealant layer. Got.

  A pouch is prepared using each of the laminates of Examples 1 to 14 obtained as described above, and a poultice (containing methyl salicylate and menthol as a volatile strong penetrating substance) as a content and for bath Each was filled with an agent (containing a fragrance component as a volatile strong penetrating substance), sealed, and left in a constant temperature room at 40 ° C.

After the elapse of 6 months, these pouches were taken out from the temperature-controlled room, and the laminate strength [N / 15 mm] between the various base materials and the sealant layer of each pouch was measured and compared with the laminate strength in the pouch before being put in the temperature-controlled room. 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. Table 1 summarizes the measurement results of the laminate strength before and after the constant temperature input.

表１からも明らかなように、実施例１〜１１に係る積層体を使用して作製されたパウチの各種基材とシーラント層間におけるラミネート強度は、揮発性物質を含む湿布薬や浴用剤を入れて４０℃で６ヵ月間保存してもほとんど変わらず、初期のラミネート強度を十分に保っている。また、実施例４の積層体においては、初期ラミネート強度で樹脂切れを示し、上記内容物を保存した後も樹脂切れを示すほど強固なラミネート強度が得られている。

As is clear from Table 1, the laminate strength between the various base materials and the sealant layer of the pouches produced using the laminates according to Examples 1 to 11 includes poultices and bathing agents containing volatile substances. Even when stored at 40 ° C. for 6 months, the initial laminate strength is sufficiently maintained. Further, in the laminate of Example 4, the initial laminate strength shows that the resin has run out, and the laminate strength is so strong that the resin runs out even after the contents are stored.

  On the other hand, some of the pouches produced using the laminates of Examples 12 to 14 have a laminate strength that is strong enough to show that the initial laminate strength is out of resin. After storing for 6 months at 40 ° C with a poultice or bath preparation containing, the laminate strength has decreased significantly to 1.5 [N / 15mm] or less, and volatile substances such as poultice and bath preparations. It has been found that it is not suitable for use in packaging materials containing contents.

It is explanatory drawing which shows the schematic structure of the laminated body which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Laminated body 2 ... Base material 3 ... Adhesive layer 4 ... Sealant layer

Claims (7)

  At least an adhesive layer and a sealant layer are provided in this order on a substrate made of either polyester, nylon or polypropylene, and the adhesive layer is a main agent and isocyanate consisting of polyester polyol, polyether polyol or acrylic polyol. The laminated body which consists of a hardening | curing agent which consists of a compound, and the ratio is 1: 99-15: 85.   The laminate according to claim 1, wherein the isocyanate compound is a bifunctional isocyanate monomer or a derivative of a trifunctional monomer of adduct, burette, or isocyanurate type.   The laminate according to claim 1, wherein the adhesive layer has a thickness of 1 μm or less.   The laminate according to any one of claims 1 to 3, wherein an easy adhesion treatment layer is formed on at least the surface of the polyester, nylon or polypropylene on the adhesive layer side.   The laminate according to claim 4, wherein the easy adhesion treatment layer is subjected to corona treatment, low-pressure plasma treatment, atmospheric pressure plasma treatment, and flame treatment.   The laminate according to claim 4, wherein the easy adhesion treatment layer is formed by coating a polyester resin or a polyurethane resin.     The laminate according to any one of claims 1 to 6, wherein the sealant layer is made of a polyethylene resin or a polypropylene resin.

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