WO2019073702A1 - Transparent laminate - Google Patents

Abstract

The transparent laminated body which has the outer layer 1, the adhesive bond layer 2, and the inner layer 3 in this order, and the adhesive bond layer 2 contains a benzotriazole type ultraviolet absorber and a benzophenone series ultraviolet absorber.

Description

Transparent laminate

The present invention relates to a transparent laminate.

In the fields of cosmetics, medicines, foods, etc., a transparent container may be used which allows the contents to be visible from the outside. When using a transparent container, in order to protect the contents from ultraviolet light, it is desirable to provide the container material with an ultraviolet absorbing ability.

In this respect, Patent Document 1 describes that an ultraviolet absorber is added to the outermost layer of the laminated sheet constituting the transparent container. Patent Document 2 describes that a UV light stabilizer is contained in the polyester resin composition layer constituting one layer of the laminate for laminate tube. Patent Document 3 describes that an unstretched thermoplastic resin layer containing an ultraviolet light absorber is used as an outer layer or an inner layer of a packaging container. The techniques described in these patent documents relate to kneading an ultraviolet absorber into one of the laminates that are the material of the transparent container.

Patent Document 4 describes a laminated film in which an organic ultraviolet absorber migration inhibiting layer composed of an oxygen atom-containing thermoplastic resin is laminated on both sides of an ultraviolet blocking layer containing an organic ultraviolet absorber.

Patent Document 5 describes that a resin composition containing an ultraviolet absorber is applied to form a barrier resin film in a laminated material for forming a laminated tube container. This technology relates to forming an ultraviolet absorbing layer by a coating method.

JP 2002-68222 A JP, 2012-116082, A JP 2012-157703 A Unexamined-Japanese-Patent No. 9-239889 JP-A-11-20073

According to the method of kneading the ultraviolet absorber into one layer of the laminate as the material of the transparent container as in the techniques of Patent Documents 1 to 3, the following is concerned.

When organic UV absorbers are used, there is a concern that the UV absorber bleeds out. When the ultraviolet absorber bleeds out due to aging or heating, the adhesion of the ink may be deteriorated when printing is performed on the container, and the lamination strength may be deteriorated when performing dry lamination.

In this respect, according to the technology using an oxygen atom-containing thermoplastic resin having a bleed-out preventing effect as described in Patent Document 4, the bleed-out of the ultraviolet absorber can be suppressed. However, the laminated film described in Patent Document 4 causes the cost of the container to increase because the manufacturing method is complicated.

On the other hand, when an inorganic ultraviolet absorber is used, there is little possibility of bleeding out even if the ultraviolet absorber is kneaded into one layer of the laminate. However, the use of an inorganic UV absorber is not preferable because it may impair the transparency of the resulting laminate.

In the technology described in Patent Document 5, in which the ultraviolet absorbing layer is formed by the application method, the thickness of the applied layer is limited, so it is considered difficult to set the conditions for expressing the ultraviolet absorbing function. Be Also in Patent Document 5, there is no specific guideline as to the type and content of the ultraviolet light absorbing material contained in the coating solution. Also, the printing method employed when the transparent container is a laminated tube is mostly UV printing. The addition of a UV absorber into the UV ink used for UV printing can cause curing failure of the print layer.

The present invention has been made in view of the above circumstances in the prior art. Therefore, an object of the present invention is to provide a transparent laminate having high transparency, printability, and an ultraviolet cut function.

The present invention is as follows.

<< Aspect 1 >>
Having an outer layer, an adhesive layer, and an inner layer in this order,
The adhesive layer contains a benzotriazole ultraviolet absorber and a benzophenone ultraviolet absorber.
Transparent laminate.
<< Aspect 2 >>
The amount of the benzotriazole-based ultraviolet absorber is 0.10 g / m ² or more and 0.30 g / m ² or less per area of the transparent laminate.
The amount of the benzophenone-based ultraviolet absorber is 0.10 g / m ² or more and 2.00 g / m ² or less per area of the transparent laminate.
The transparent laminated body as described in aspect 1.
<< Aspect 3 >>
The transparent laminate according to aspect 1 or 2, wherein the outer layer and the inner layer are each a layer having a single-layer structure or a multi-layer structure including an LLDPE film.
<< Aspect 4 >>
The transparent laminate according to aspect 3, wherein the inner layer is a layer having a multilayer structure further comprising a PET layer.
<< Aspect 5 >>
The adhesive layer is composed of a cured product of a two-component curable UV-absorbing adhesive composition comprising a two-component curable adhesive, a benzotriazole-based UV absorber and a benzophenone-based UV absorber. The transparent laminate according to any one of Aspects 1 to 4, which is a layer.
<< Aspect 6 >>
The transparent laminate according to aspect 5, wherein the curing agent of the two-component curing type adhesive is an aliphatic curing agent.
<< Aspect 7 >>
For the above transparent laminate, when the ultraviolet transmittance is measured under the conditions of a measurement wavelength of 200 nm to 500 nm, a scanning speed of 600 nm / min, and a slit width of 4.00 nm, the ultraviolet transmittance at wavelengths of 360 nm, 330 nm, and 270 nm The transparent laminate according to any one of Embodiments 1 to 6, which is also 5.0% or less.
<< Aspect 8 >>
The transparent laminate according to any one of Aspects 1 to 7, which is used for a tube container.
<< Aspect 9 >>
A method for producing a transparent laminate, comprising laminating an outer layer and an inner layer through an adhesive layer containing a benzotriazole-based ultraviolet absorber and a benzophenone-based ultraviolet absorber.
<< Aspect 10 >>
By dry lamination using a two-part curable UV-absorbing adhesive composition comprising the above outer layer and the above-mentioned inner layer, a two-part curable adhesive, a benzotriazole-based UV absorber and a benzophenone-based UV absorber The manufacturing method of the transparent laminated body of aspect 9 which laminates | stacks.
<< Aspect 11 >>
Adhesive,
Benzotriazole type ultraviolet absorber and benzophenone type ultraviolet absorber;
An ultraviolet-absorbing adhesive composition comprising ethyl acetate.
<< Aspect 12 >>
The ultraviolet-absorbing adhesive composition according to aspect 11, wherein the adhesive is a two-part curable adhesive.

According to the present invention, a transparent laminate having high transparency, printability, and an ultraviolet cut function is provided.

FIG. 1 is a schematic cross-sectional view for explaining the layer configuration of the transparent laminate of the present invention. FIG. 2 is an ultraviolet ray transmittance chart of the transparent laminate sample obtained in each of Comparative Examples 1 to 3. FIG. 3 is an ultraviolet ray transmission chart of the transparent laminate sample obtained in Example 5. Fig.4 (a) is an ultraviolet-ray transmittance chart before wiping off the surface of the transparent laminated body obtained in Example 13 by ethanol, FIG.4 (b) wiped off the surface of this transparent laminated body with ethanol It is a ultraviolet ray transmittance chart after. Fig.5 (a) is an ultraviolet-ray transmittance chart before wiping off the back surface of the transparent laminated body obtained in Example 13 by ethanol, FIG.5 (b) wiped the back surface of this transparent laminated body with ethanol It is a ultraviolet ray transmittance chart after.

«Transparent laminate»
The transparent laminate of the present invention is, for example, as shown in FIG.
Having an outer layer (1), an adhesive layer (2), and an inner layer (3) in this order,
The adhesive layer (2) contains a benzotriazole-based ultraviolet absorber and a benzophenone-based ultraviolet absorber.

The present invention is characterized in that the adhesive layer in the transparent laminate contains two types of UV absorbers, a benzotriazole type UV absorber and a benzophenone type UV absorber.

The adhesive layer in the transparent laminate is often formed by applying as a solution-like adhesive composition in which an adhesive material is dissolved in a solvent. There is a limit to the amount of the adhesive composition applied, so the resulting adhesive layer is a thin layer, and thus the absolute amount of UV absorber that can be included in the adhesive layer is limited. On the other hand, in order to prevent deterioration of the contents when the transparent laminate is used as a packaging container, it is required to block the transmission of a wide range of ultraviolet light.

UV absorbers that can block the transmission of a broad range of UV light, but that are soluble in the solvent used in the adhesive composition, or as small as small enough to be included in the adhesive layer of the thin layer No combination of UV absorbers is known in the prior art.

The present invention has succeeded in simultaneously meeting all the above requirements by including two types of ultraviolet absorbers, benzotriazole type ultraviolet absorber and benzophenone type ultraviolet absorber, in the adhesive layer in the transparent laminate. It is a thing.

Outer layer
The outer layer in the transparent laminate of the present invention may be a transparent resin layer, and in particular, may be a single layer structure or a multilayer structure including a transparent resin layer having heat sealability.

When manufacturing a container using the transparent laminate of the present invention, the sheet-like transparent laminate is rolled into a cylindrical shape, the end portions of the outer layer and the inner layer are overlapped, and this overlapping portion is heat sealed to form a cylindrical body. There is something to do. At this time, since the outer layer and the inner layer are heat-sealed so as to fuse, it is preferable that the heat sealability with the inner layer resin be good as the heat sealable transparent resin constituting the outer layer.

Examples of the transparent resin layer, particularly the transparent resin having heat sealability as described above, include polyethylene (PE). Specifically, polyethylene may be, for example, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE) or the like. The transparent resin having heat sealability may be a sheet of these resins, a film, or a coating film formed using a composition containing these resins, and in particular, may be an LLDPE film. Thus, the outer layer may be a single layer or multi-layer layer comprising an LLDPE film.

The outer layer in the transparent laminate of the present invention may have, for example, a polyester layer, an inorganic vapor deposition layer, etc. in addition to the transparent resin layer, particularly the LLDPE film. The polyester layer may be, for example, a uniaxial or biaxial stretched film composed of polyethylene terephthalate (PET) or the like.

The thickness of the outer layer may be, for example, 20 μm or more, 40 μm or more, 60 μm or more, or 80 μm or more, and may be, for example, 150 μm or less, 140 μm or less, 130 μm or less, 120 μm or less, 110 μm or less, or 100 μm or less.

<Adhesive layer>
The adhesive layer of the transparent laminate of the present invention contains both a benzotriazole-based ultraviolet absorber and a benzophenone-based ultraviolet absorber.

The adhesive layer in the transparent laminate of the present invention is optional as long as it contains both a benzotriazole-based ultraviolet absorber and a benzophenone-based ultraviolet absorber, and the outer layer and the inner layer can be adhered and laminated. Good. The adhesive layer may be a cured product of an adhesive composition containing a one-component or two-component adhesive.

The one-component adhesive may be, for example, a vinyl acetate resin adhesive, an ethylene / vinyl acetate copolymer adhesive, an acrylic resin adhesive, a vinyl chloride resin adhesive, a chloroprene rubber adhesive, etc. .

The two-component adhesive may be, for example, a two-component curable adhesive composed of a main agent and a curing agent, such as an epoxy resin adhesive, a silicone resin adhesive, and a polyurethane adhesive.

The adhesive may have no aromatic ring so that the resulting transparent laminate is not discolored by the irradiation of ultraviolet light. For example, the curing agent of the two-part reactive adhesive may be an aliphatic curing agent.

The adhesive layer in the transparent laminate of the present invention is prepared by dissolving the above-mentioned adhesive, for example, a main agent and a curing agent of a two-component curing adhesive, and a benzotriazole ultraviolet absorber and a benzophenone ultraviolet absorber in a solvent. It can be obtained by curing a two-component UV curable adhesive composition. The solvent may be, for example, ethyl acetate and the like.

The adhesive layer in the transparent laminate of the present invention has an adhesive layer amount of 2.0 g / m ² or more as the amount of the adhesive layer per unit area of the transparent laminate, from the viewpoint of sufficiently increasing the lamination strength of the outer layer and the inner layer. .5g / ^{m 2} or more, 3.0 g / ^{m 2} or more, 3.5 g / ^{m 2} or more, or 4.0 g / ^{m 2} or more may be an amount. On the other hand, the amount of the adhesive layer per unit area of the transparent laminate is 8.0 g / m ² or less from the viewpoint of securing the laminate strength or enabling the production by the coating method, or both of them. , 7.0 g / m ² or less, 6.0 g / m ² or less, or 5.0 g / m ² or less.

(Benzotriazole UV absorber)
The benzotriazole-based ultraviolet absorber may be a hydroxyphenyl-substituted benzotriazole compound, a halide thereof or the like.

Specifically, the hydroxyphenyl substituted benzotriazole compound is, for example, 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-5-t-butylphenyl) benzotriazole, 2- (2- (2-hydroxy-5-methylphenyl) benzotriazole) 2-hydroxy-3,5-dimethylphenyl) benzotriazole, 2- (2-methyl-4-hydroxyphenyl) benzotriazole, 2- (2-hydroxy-3-t-butyl-5-methylphenyl) benzotriazole, It may be 2- (2-hydroxy-3,5-di-t-amylphenyl) benzotriazole, 2- (2-hydroxy-3,5-di-t-butylphenyl) benzotriazole and the like.

The halide of the hydroxyphenyl substituted benzotriazole compound is, for example, 2- (2-hydroxy-3-t-butyl-5-methylphenyl) -5-chlorobenzotriazole (alias: 2- (5-chloro-2H-benzo) Triazol-2-yl) -6-t-butyl-4-methylphenol), 2- (2-hydroxy-3,5-di-t-butylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy) -3- (2-Methylpentan-2-yl) -5- (2-methylbutan-2-yl) phenyl) -5-chlorobenzotriazole, 2- (2-hydroxy-3-t-butyl-5- ( It may be 2-octyloxycarbonylethyl) phenyl) -5-chlorobenzotriazole or the like.

The amount of the benzotriazole-based ultraviolet absorber in the adhesive layer, per area of the transparent laminate, e.g., 0.10 g / ^{m 2} or more, 0.13 g / ^{m 2} or more, 0.15 g / ^{m 2} or more, 0. 17 g / m ² or more, 0.19 g / m ² or more, or 0.21 g / m ² or more. When the amount of the benzotriazole-based ultraviolet absorber used is sufficiently large, ultraviolet light can be effectively blocked, and in particular, in the wavelength region of 380 nm to 400 nm where blocking by the benzophenone-based ultraviolet absorber described below is insufficient. Ultraviolet light and ultraviolet light near a wavelength of 310 nm can be sufficiently blocked.

The amount of the benzotriazole-based ultraviolet absorber in the adhesive layer, per area of the transparent laminate, e.g., 0.30 g / ^{m 2} or less, 0.28 g / ^{m 2} or less, 0.25 g / ^{m 2} or less, 0. It may be 23 g / m ² or less, or 0.21 g / m ² or less. The adhesive layer in which the amount of the benzotriazole-based ultraviolet absorber used is not excessive can laminate the outer layer and the inner layer with high adhesion, and the laminate strength between both layers can be made sufficiently high.

The amount of the benzotriazole-based UV absorber used in the adhesive layer is, for example, 0.13 g / m ² or more per area of the transparent laminate, in consideration of the balance between UV blocking properties and laminate strength as much as possible. It may be in the range of .28 g / m ² or less.

(Benzophenone-based ultraviolet absorber)
The benzophenone based ultraviolet absorber may be a hydroxy-substituted benzophenone compound or the like.

Examples of hydroxy-substituted benzophenone-based UV absorbers include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone and 2-hydroxy-4-n-octoxybenzophenone (alias: [2 -Hydroxy-4- (octyloxy) phenyl] (phenyl) methanone), 2-hydroxy-4-n-dodecyloxybenzophenone, 2-hydroxy-4-n-octadecyloxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone , 2-hydroxy-4-methoxy-5-sulfobenzophenone, 2-hydroxy-5-chlorobenzophenone, 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4 4'-dimethoxyphenyl, 2,2 ', may be 4,4'-tetrahydroxy benzophenone.

The amount of the benzophenone ultraviolet absorber in the adhesive layer, per area of the transparent laminate, e.g., 0.10 g / ^{m 2} or more, 0.13 g / ^{m 2} or more, 0.15 g / ^{m 2} or more, 0.17 g / M ² or more, 0.18 g / m ² or more, or 0.20 g / m ² or more. When the amount of the benzophenone-based ultraviolet absorber used is sufficiently large, it is possible to sufficiently block ultraviolet light around a wavelength of 330 nm, in particular, for which blocking by the benzotriazole-based ultraviolet absorber is insufficient.

The amount of the benzophenone ultraviolet absorber in the adhesive layer, per area of the transparent laminate, e.g., 2.00 g / ^{m 2} or less, 1.80 g / ^{m 2} or less, 1.50 g / ^{m 2} or less, 1.30 g / ^{m 2} or less, 1.00 g / ^{m 2} or less, 0.80 g / ^{m 2} or less, 0.50 g / ^{m 2} or less, 0.40 g / ^{m 2} or less, or 0.30 g / ^m may be ² or less. The adhesive layer in which the amount of the benzophenone-based ultraviolet absorber used is not excessive can laminate the outer layer and the inner layer with high adhesion, and the laminate strength between both layers can be made sufficiently high.

The amount of the benzophenone-based UV absorber used in the adhesive layer is, for example, 0.15 g / m ² or more per area of the transparent laminate, in consideration of the balance between the UV blocking property and the laminate strength. It may be in the range of 76 g / m ² or less.

(Combined use of benzotriazole type ultraviolet absorber and benzophenone type ultraviolet absorber)
The total amount of the benzotriazole-based ultraviolet absorber and the benzophenone-based ultraviolet absorber in the adhesive layer is, for example, 0.30 g / m ² or more, 0.35 g / m ² or more, per unit area of the transparent laminate. .40g / ^{m 2} or more, or may be at 0.45 g / ^{m 2} or more, e.g., 2.50 g / ^{m 2} or less, 2.00 g / ^{m 2} or less, 1.50 g / ^{m 2} or less, 1.00 g / m ² or less, or 0.50 g / ^m may be ² or less.

A preferred UV absorber in the adhesive layer for making the laminate strength between the outer layer and the inner layer in the transparent laminate sufficiently high and exhibiting a high UV absorption ability and a high transparency, and a transparent laminate usage per unit area of the transparent laminate, and 0.13 g / ^{m 2} or more 0.28 g / ^{m 2} or less of benzotriazole ultraviolet absorber, 0.15 g / ^{m 2} or more 1.76 g / ^{m 2} or less of You may use in combination with a benzophenone series ultraviolet absorber. Particularly preferably, a benzotriazole ultraviolet absorber 0.23 g / ^{m 2,} a combination of benzophenone ultraviolet absorber 0.24 g / ^{m 2.}

(Measurement of UV absorber content)
The content of each of the benzotriazole-based ultraviolet absorber and the benzophenone-based ultraviolet absorber in the transparent laminate is obtained by immersing the transparent laminate sample in a solvent to extract the ultraviolet absorber and concentrating as necessary. It can quantify by measuring the liquid chromatography of the extracted liquid. The measurement results of liquid chromatography may be converted to values per unit area of the original transparent laminate sample. As an extraction solvent, for example, chloroform is suitable.

<Inner layer>
The inner layer in the transparent laminate of the present invention may be a layer having a single layer structure or a multilayer structure including a transparent resin layer.

When manufacturing the container using the transparent laminate of the present invention, if it is intended to fuse the inner layer and the outer layer, the inner layer may include a transparent resin layer having heat sealability, and an outer layer resin May contain a transparent resin layer having good heat sealability.

As a transparent resin which comprises an inner layer, polyethylene etc. can be mentioned, for example, For example, you may select suitably from LDPE, LLDPE, MDPE, HDPE etc., and may use. The transparent resin constituting the inner layer may be a sheet of these resins, a film, or a coating film formed using a composition containing these resins, and in particular may be an LLDPE film. Thus, the inner layer may be a single layer or multi-layer layer comprising an LLDPE film.

The inner layer in the transparent laminate of the present invention may have a base layer which imparts rigidity to the transparent laminate, in addition to the transparent resin layer as described above, particularly the LLDPE film. The base material layer may be, for example, a polyester layer, a nylon layer or the like. The polyester layer may be, for example, a uniaxial or biaxial stretched film composed of polyethylene terephthalate (PET) or the like. The nylon layer may be, for example, a uniaxial or biaxial stretched film made of 6-nylon, 6,6-nylon or the like.

From the viewpoint of exerting the effect of imparting rigidity effectively, the thickness of the base material layer may be, for example, 8 μm or more, 10 μm or more, or 12 μm or more. On the other hand, if the base layer is too thick, cost-effectiveness is disadvantageous, and from the viewpoint of avoiding an adverse effect on side seam formation during sealing, the base layer has a thickness of, for example, 25 μm. Hereinafter, it may be 20 μm or less, or 15 μm or less.

The thickness of the inner layer may be, for example, 20 μm or more, 40 μm or more, 60 μm or more, or 80 μm or more, and for example, 400 μm or less, 350 μm or less, 300 μm or less, 250 μm or less, 200 μm or less, 150 μm or less, or 100 μm or less Good. When the inner layer comprises a substrate layer, these thicknesses are values including the thickness of the substrate layer.

<Printing layer>
The transparent laminate of the present invention may optionally include a printing layer. The print layer may include, for example, a print name such as a product name of the contents, an explanation, notes, and the like, and a design for stimulating purchase intention. The printing layer may be disposed on either the outer layer or the inner layer. When the outer layer and the inner layer are multilayers, they may be disposed in any of these multilayers. For example, a printing layer may be disposed on the outermost surface of the inner layer opposite to the side in contact with the content, and the outer layer may be adhered onto the printing layer via the predetermined adhesive layer of the present invention, It is included in the scope of the present invention.

The formation of the printing layer may be performed using a known ink composition (for example, a UV ink composition) by an appropriate printing method such as offset printing, gravure printing, flexographic printing, letterpress printing, and the like.

<< Production method of transparent laminates >>
The transparent laminate of the present invention may be produced, for example, by a method comprising laminating an outer layer and an inner layer via an adhesive layer containing a benzotriazole-based ultraviolet absorber and a benzophenone-based ultraviolet absorber.

As the outer layer, the inner layer, and the ultraviolet light absorber, desired ones may be selected and used from those exemplified above as the material constituting the transparent laminate. When the outer layer or the inner layer has a multilayer structure, for example, it may be used after being laminated by an appropriate method such as melt extrusion lamination or dry lamination. Prior to lamination in the case where the outer layer or the inner layer has another layer configuration, and adhesion between the outer layer and the inner layer, the processed surface of the layer may be subjected to an appropriate treatment such as corona discharge treatment in advance.

The adhesive layer may be formed, for example, on the outer layer or the inner layer or on both sides.
Adhesive,
Benzotriazole type ultraviolet absorber and benzophenone type ultraviolet absorber;
After application of the UV-absorbing adhesive composition comprising ethyl acetate, the outer layer and the inner layer are laminated and then formed by removing the solvent in the UV-absorbing adhesive composition and curing the adhesive May be done.

The adhesive contained in the above-mentioned UV-absorbing adhesive composition may be a one-component adhesive or a two-component (two-component curing) adhesive, and the adhesive exemplified above Among the agents, desired ones may be selected and used. The type and amount of each of the benzotriazole-based ultraviolet absorber and the benzophenone-based ultraviolet absorber may be appropriately set according to the desired adhesive layer in the transparent laminate. The amount of ethyl acetate used is such that the solid content in the resulting UV-absorbing adhesive composition is, for example, 10% by weight or more, 15% by weight or more, or 20% by weight or more, for example, 60% by weight or less, 50% It may be used in an amount of less than 40% by weight.

In the transparent laminate of the present invention, in particular, the outer layer and the inner layer are laminated by dry lamination using a two-component curable UV-absorbing adhesive composition containing a two-component curable adhesive and a UV absorber. Is preferred. The two-part curable UV-absorbing adhesive composition may contain a two-part curable adhesive, a benzotriazole-based UV absorber and a benzophenone-based UV absorber, and ethyl acetate.

<< Characteristics of Transparent Laminates >>
The transparent laminate of the present invention is highly transparent, particularly highly transparent to visible light, and excellent in the blocking property to ultraviolet light.

With regard to the blocking property to ultraviolet light, the ultraviolet-visible / near-infrared spectrophotometer is used for the transparent laminate of the present invention, under the conditions of a measurement wavelength of 200 nm to 500 nm, a scanning speed of 600 nm / min, and a slit width of 4.00 nm. When the transmittance is measured, the ultraviolet transmittance at wavelengths of 360 nm, 330 nm, and 270 nm may be 5.0% or less. The ultraviolet light transmittance at 360 nm of the transparent laminate at this time may be 4.5% or less, 4.0% or less, 3.5% or less, or 3.0% or less. The ultraviolet transmittance at 330 nm and 270 nm of the transparent laminate may be 4.0% or less, 3.0% or less, 2.0% or less, or 1.5% or less, respectively.

As described above, the transparent laminate of the present invention has a high blocking efficiency to ultraviolet light, particularly in the wavelength region of 360 nm or less. Therefore, the transparent laminate of the present invention is provided with a high degree of ultraviolet blocking properties even when the outer layer and the inner layer are materials (for example, PE) which do not have ultraviolet blocking properties. Moreover, PET generally used as a laminate material blocks ultraviolet light in a wavelength range of 300 nm or less well, but exhibits significant transmittance in a wavelength range of 320 nm or more. Since the transparent laminate of the present invention can effectively block ultraviolet light of 360 nm or less even when the outer layer and the inner layer are composed of PET, the ultraviolet light originally possessed by the material of the outer layer and the inner layer The blocking range will be expanded.

With respect to the transparency to visible light, the haze of the transparent laminate of the present invention measured according to JIS K 7105 is, for example, 40% or less, 38% or less, 36% or less, 34% or less, 32% or less It may be 30% or less.

In the transparent laminate of the present invention, although the outer layer and the inner layer are adhered by the adhesive layer containing the ultraviolet absorber, the laminate strength between both layers is very high. Specifically, with respect to a test piece of width 15 mm produced from the transparent laminate of the present invention, the T-peel strength measured according to JIS K 6854 is 10.0 N / 15 mm or more, 12.0 N / 15 mm or more, It may be 13.0 N / 15 mm or more, 13.5 N / 15 mm or more, 14.0 N / 15 mm or more, 14.5 N / 15 mm or more, or 15 N / 15 mm or more.

<< Applications of Transparent Laminates >>
The transparent laminate of the present invention may be used, for example, as a laminate tube container, a laminate packaging bag, and the like. Specifically, the transparent laminate of the present invention may be used, for example, as a laminated tube container for cosmetics, pharmaceuticals, food and the like.

The laminate tube container may comprise a body, a mouth smaller in diameter than the body, and a shoulder connecting the body and the mouth. The laminated tube container is formed, for example, by rolling the transparent laminate of the present invention into a cylindrical shape to form a cylindrical body, and welding it to a separately manufactured shoulder and mouth, forming the shoulder by compression molding It may be manufactured by an appropriate method etc. including a method of simultaneously performing welding with the cylindrical body and the like.

The resin films and reagents used in the following examples and comparative examples are as follows. In the following, the number in parentheses after the name of the resin film is the film thickness (μm).

<Resin film>
LLDPE 1 (100): manufactured by Tamapoly Co., Ltd., linear low density polyethylene, product name "SE620N", thickness 100 μm
LLDPE 2 (80): manufactured by Toyobo Co., Ltd., linear low density polyethylene, product name “LIX-NP L4102”, thickness 80 μm
LDPE: manufactured by Asahi Kasei Co., Ltd., low density polyethylene, product name "Suntec-LD M1880E"
PET (12): Unitika Co., Ltd. product, biaxially stretched polyester film, product name "PETB", thickness 12 μm

<adhesive>
From ester-based main agent (made by Toyo Ink Co., Ltd., product name "TM277", non-volatile content 55% by weight) and aliphatic curing agent (made by Toyo Ink Co., Ltd., product name "CAT-RT86, non-volatile content 60% by weight) Two-component reaction curable dry laminate adhesive

<UV absorber>
LA-36: manufactured by ADEKA Co., Ltd., benzotriazole-based ultraviolet absorber, 2- (5-chloro-2H-benzotriazol-2-yl) -6-t-butyl-4-methylphenol, trade name “Adekastab LA- 36 "
1413: manufactured by ADEKA Co., Ltd., benzophenone-based ultraviolet absorber, [2-hydroxy-4- (octyloxy) phenyl] (phenyl) methanone, product name "Adecastab 1413"

<< Evaluation of UV transmittance >>
Comparative Examples 1 to 4 and Examples 1 to 8
(1) Preparation of UV Absorbent Adhesive Composition A solution A was obtained by mixing 10 g of an adhesive (main agent) (5.5 g of non volatile matter) and 11.94 g of ethyl acetate. A predetermined amount of each of the ultraviolet absorbers “LA-36” and “1413” was weighed and mixed with the solution A to obtain a solution B. Next, 2 g of an adhesive (hardening agent) (1.2 g of non-volatile components) was mixed with the solution B to prepare a two-component curable ultraviolet-absorbing adhesive composition.

Here, the UV absorbers “LA-36” and “1413” are each 100% by weight of the solid content in the adhesive (that is, the total weight of the adhesive (main agent) and the non-volatile components of the adhesive (hardener)). The amount which becomes the ratio (weight%) shown by the "weight ratio with respect to adhesive agent" column of Table 1 when mixing it as% was mixed and used.

In Comparative Example 4, the amount of the benzotriazole-based ultraviolet absorber “LA-36” used was 7% by weight based on the solid content in the adhesive (0.34 g / m ² per unit area of the transparent laminate) The preparation of the UV-absorbing adhesive composition was attempted by setting the amount to be 2.), but since the UV absorber did not completely dissolve, the subsequent experiments were not conducted.

(2) Preparation of Transparent Laminate Two sheets of LLDPE 1 (100) were prepared, and each side was subjected to corona discharge treatment.

The UV-absorbing adhesive composition is applied by gravure coating at a coating weight of 4.2 g / m ² in terms of solid content on one corona discharge-treated surface of LLDPE 1 (100), and another one A transparent laminate of the following layer configuration was obtained by bonding to the corona discharge treated surface of LLDPE 1 (100) and leaving it to stand at 40 ° C. for 5 days (120 hours) to cure the adhesive.
LLDPE1 (100) / UV absorber-containing adhesive layer / LLDPE1 (100)

(3) Measurement of Content of Ultraviolet Absorber The obtained transparent laminate was cut into a square sheet of 10 cm × 10 cm to obtain a sample. This sheet was cut into substantially square pieces of about 1 cm on a side, and immersed in chloroform to extract the ultraviolet absorber. The extract was concentrated under reduced pressure and then subjected to liquid chromatography to quantify the amount of the ultraviolet absorber contained in the extract, and converted to a value per unit area of the transparent laminate sample used for the measurement.

(4) Measurement of UV Transmittance The UV transmittance of the transparent laminate sample obtained under the following conditions was measured using an ultraviolet-visible near-infrared spectrophotometer, product name "UH4150" manufactured by Hitachi High-Tech Science Co., Ltd. It was measured. At this time, ultraviolet ray transmittances at wavelengths of 360 nm, 330 nm, and 270 nm were adopted as an indicator of the transparency of the transparent laminate.
Measurement wavelength: 200 nm to 500 nm
Scanning speed: 600 nm / min Sampling interval: 1 nm
Slit width: 4.00 nm

(5) Measurement of Haze The haze of the obtained transparent laminate was measured according to JIS K 7105 using a haze, transmittance, and reflectometer manufactured by Murakami Color Research Laboratory, product name "HR100". .

(6) Presentation of measurement results The ultraviolet transmittances at wavelengths of 360 nm, 330 nm, and 270 nm obtained for the transparent laminate samples of Comparative Examples 1 to 3 and Examples 1 to 8 and the measurement results of the haze were each transparent laminate It showed in Table 1 with content of the ultraviolet absorber in it. In addition, FIG. 2 shows ultraviolet ray transmittance charts of transparent laminate samples of Comparative Examples 1 to 3 used as grounds for ultraviolet ray transmittances of wavelengths 360 nm, 330 nm, and 270 nm, and FIG. The ultraviolet transmittance chart is shown in FIG.
Although the UV transmittance charts of Examples 1 to 4 and 6 to 8 are omitted, the UV transmittance values in these Examples in Table 1 are the values extracted from the corresponding UV transmittance charts. It is.

With reference to Table 1 and FIGS. 2 and 3, the following is understood.

In the transparent laminate sample of Comparative Example 1 including only the benzotriazole-based ultraviolet absorber "LA-36" as the ultraviolet absorber in the adhesive layer, the ultraviolet transmittance sharply decreases at a wavelength shorter than 400 nm, and it is around 360 nm In this case, the transmissivity level was reached without any problem, but peaks with high transmissivity were observed near wavelengths of 330 nm and 270 nm. Comparative example in which the amount of the benzotriazole-based ultraviolet light absorber “LA-36” is increased to 7% by weight (corresponding to 0.34 g / m ² per unit area of the transparent laminate) with respect to the nonvolatile matter in the adhesive composition In No. 4, as described above, the UV absorber in the adhesive composition could not be completely dissolved in the solvent.

On the other hand, in the transparent laminate sample of Comparative Example 2 including only the benzophenone series ultraviolet absorber “1413” as the ultraviolet absorber in the adhesive, the high ultraviolet transmittance was maintained up to around 380 nm. The ultraviolet transmittance of the transparent laminate sample of Comparative Example 2 decreased at a wavelength lower than 380 nm, but maintained a high level near 360 nm, and a peak with high transmittance near 310 nm and 270 nm was observed. It was done.

The ultraviolet light transmittance of the transparent laminate sample of Comparative Example 3 in which the content of the benzophenone series ultraviolet light absorber “1413” in Comparative Example 2 was increased was generally decreased in the wavelength range shorter than 380 nm, but it was around 360 nm The level of transmittance was still high, and peaks with high transmittance around 310 nm and 270 nm were also maintained.

On the other hand, the transparent laminate sample of Example 1 containing both benzotriazole-based ultraviolet absorber “LA-36” and benzophenone-based ultraviolet absorber “1413” as the ultraviolet absorber in the adhesive layer has a thickness of 400 nm. The ultraviolet transmittance sharply decreased at a shorter wavelength and reached a satisfactory transmittance level near 360 nm, and no rising peaks of transmittance near wavelengths 330 nm and 310 nm were observed. Although a peak at which the ultraviolet light transmittance slightly increases is confirmed around the wavelength of 270 nm, it is not a level that causes a problem. The ultraviolet transmittances at the wavelengths of 360 nm, 330 nm, and 270 nm measured for the transparent laminate samples of Examples 2 to 8 all show low values.

In addition, all of the transparent laminates obtained here had low haze and had high transparency to visible light.

From the above, the embodiment of the present invention which includes both the benzotriazole-based ultraviolet absorber and the benzophenone-based ultraviolet absorber in the adhesive layer exhibits high transparency to visible light while having a wavelength shorter than 360 nm. It has been verified that the UV radiation in the region can be absorbed and the UV transmission in the region measured in this example can be reduced to a problem-free level.

<< Evaluation of laminate strength >>
Comparative Example 5 and Examples 9 to 14
(1) Production of inner layer (base laminate) According to the following procedure, an inner layer having a print pattern of the following layer constitution was produced.
(Printing design) / LDPE (40) / PET (12) / adhesive layer / LLDPE 1 (100) / LDPE (70) / LLDPE 1 (100)

A corona discharge treatment was applied to one side of the PET (12). LLDPE1 (100) is laminated on the corona discharge treated surface of this PET (12) via a two-component reaction curing type dry laminating adhesive layer, and laminate A (PET (12) / adhesive layer / LLDPE1 (100) )) Got.

Another LLDPE 1 (100) is laminated via the melted LDPE on the LLDPE 1 (100) side of the laminate A, and a laminate B (PET (12) / adhesive layer / LLDPE 1 (100) / LDPE (70) / LLDPE1 (100) was obtained.

A fused LDPE is laminated via the anchor coat layer on the PET (12) side of the laminate B to form a 40 μm thick LPDE layer (LDPE (40)), the laminate C (LDPE (40)) / PET (12) / adhesive layer / LLDPE1 (100) / LDPE (70) / LLDPE1 (100)) was obtained.

Furthermore, by printing a pattern using UV ink on a partial region of the surface of the laminate C on the LDPE (40) side, a base having a print pattern having a seven-layer structure including the layer of the print pattern. A laminate was obtained.

(2) Preparation of UV Absorbent Adhesive Composition When the solid content in the adhesive is 100% by weight of each of the UV absorbers “LA-36” and “1413”, the “adhesion of Table 2” In the same manner as in [Comparative Examples 1 to 4 and Examples 1 to 8] except for the amount (weight%) indicated in the “Weight ratio to agent” column, a two-component curing type of ultraviolet absorptivity An adhesive composition was prepared. The adhesive composition in Comparative Example 5 does not contain an ultraviolet absorber.

(3) Preparation of Transparent Laminate The UV-absorbing adhesive composition is gravure-coated onto the surface of the base laminate on the LDPE (40) side having a printed pattern by conversion of a solid content of 4.2 g / m ² . It apply | coated by the application quantity and the transparent laminated body of the following layer structure was obtained by bonding together to LLDPE2 (80).
LLDPE 2 (80) / UV absorber-containing adhesive layer / (printed pattern) / LDPE (40) / PET (12) / adhesive layer / LLDPE 1 (100) / LDPE (70) / LLDPE 1 (100)

(4) Measurement of laminate strength From the transparent laminate obtained above, a strip-shaped test piece of width 15 mm × length 100 mm is cut out with the MD direction as the major axis, and pasted through the ultraviolet absorber-containing adhesive layer The space between the combined LLDPE 2 (80) layer and the LDPE (40) layer was peeled off, and the T-peel strength was measured under the following conditions in accordance with JIS K 6854. The test was performed 105 times for each test piece, and the average value was adopted as the laminate strength.
Measuring device: manufactured by Toyo Seiki Seisakusho Co., Ltd., strograph, product name "VES10"
Gripping movement speed: 300 mm / min

(5) Measurement of Content of UV Absorber The UV absorber contained in the produced transparent laminate is quantified by liquid chromatography in the same manner as in [Comparative Examples 1 to 4 and Examples 1 to 8]. did.

(6) Presentation of Measurement Results The measurement results of laminate strength obtained for the transparent laminate samples of Comparative Example 5 and Examples 9 to 14 are shown in Table 2 together with the content of the ultraviolet light absorber in each transparent laminate. Indicated.

As is apparent from Table 2, even when laminated using an adhesive composition containing both of benzotriazole-based ultraviolet absorber “LA-36” and benzophenone-based ultraviolet absorber “1413”, lamination between layers The strength was not lost and showed high laminate strength. It should also be noted that in the above embodiment, the design is printed on the outermost surface of the inner layer and then laminated with the outer layer.

"Confirmation of presence or absence of bleed out"
In the above-mentioned transparent laminate, the presence or absence of bleed out of the ultraviolet absorber was confirmed.
The ultraviolet transmittances before and after wiping when the front and back surfaces of the transparent laminate obtained in Example 13 were wiped with ethanol, respectively, were measured. This measurement was performed under the following conditions using a UV-VIS spectrophotometer UH4150 manufactured by Hitachi High-Tech Science.
Measurement wavelength: 210 nm to 600 nm
Scanning speed: 600 nm / min Sampling interval: 1 nm
Slit width: 4.00 nm

The chart of the ultraviolet ray transmittance thus obtained is shown in FIG. 4 and FIG. Fig.4 (a) is an ultraviolet-ray transmittance chart before wiping off the surface of the transparent laminated body obtained in Example 13 by ethanol, FIG.4 (b) wiped off the surface of this transparent laminated body with ethanol It is a ultraviolet ray transmittance chart after. Fig.5 (a) is an ultraviolet-ray transmittance chart before wiping off the back surface of the transparent laminated body obtained in Example 13 by ethanol, FIG.5 (b) wiped the back surface of this transparent laminated body with ethanol It is a ultraviolet ray transmittance chart after.

As is clear from FIGS. 4 and 5, no difference was observed in the ultraviolet light transmittance before and after wiping the front or back surface of the transparent laminate with ethanol. From this, it was confirmed that bleed-out of the ultraviolet absorber to such an extent that affects the ultraviolet absorptivity did not occur on the front surface or the back surface of the transparent laminate.

<< Measurement of Haze >>
The haze of the transparent portion of the transparent laminate produced in Example 13 which does not have a printed pattern is measured using the haze, transmittance, and reflectometer manufactured by Murakami Color Research Laboratory, product name "HR 100", JIS It measured according to K7105. The haze of this transparent laminate sample was 27.9% as shown in Table 3, and it was confirmed that the container had transparency enabling visual recognition of the contents.

1 outer layer 2 adhesive layer 3 inner layer

Claims (12)

Having an outer layer, an adhesive layer, and an inner layer in this order,
The adhesive layer contains a benzotriazole-based ultraviolet absorber and a benzophenone-based ultraviolet absorber.
Transparent laminate. The amount of the benzotriazole-based ultraviolet absorber is 0.10 g / m ² or more and 0.30 g / m ² or less per area of the transparent laminate,
The amount of the benzophenone-based ultraviolet absorber is 0.10 g / m ² or more and 2.00 g / m ² or less per area of the transparent laminate.
The transparent laminate according to claim 1. The transparent laminate according to claim 1 or 2, wherein each of the outer layer and the inner layer is a layer having a single layer configuration or a multilayer configuration including an LLDPE film. The transparent laminate according to claim 3, wherein the inner layer is a layer having a multilayer structure further comprising a PET layer. The adhesive layer is composed of a cured product of a two-component curable UV-absorbing adhesive composition comprising a two-component curable adhesive, a benzotriazole-based UV absorber and a benzophenone-based UV absorber. The transparent laminate according to any one of claims 1 to 4, which is a layer. The transparent laminate according to claim 5, wherein the curing agent of the two-component curing adhesive is an aliphatic curing agent. With respect to the transparent laminate, when the ultraviolet transmittance is measured under the conditions of a measurement wavelength of 200 nm to 500 nm, a scanning speed of 600 nm / min, and a slit width of 4.00 nm, the ultraviolet transmittance at wavelengths of 360 nm, 330 nm, and 270 nm The transparent laminate according to any one of claims 1 to 6, which is also 5.0% or less. The transparent laminate according to any one of claims 1 to 7, which is used for a tube container. A method for producing a transparent laminate, comprising laminating an outer layer and an inner layer through an adhesive layer containing a benzotriazole-based ultraviolet absorber and a benzophenone-based ultraviolet absorber. The outer layer and the inner layer are dry-laminated using a two-part curable UV-absorbing adhesive composition comprising a two-part curable adhesive, a benzotriazole-based UV absorber and a benzophenone-based UV absorber The manufacturing method of the transparent laminated body of Claim 9 which laminates | stacks. Adhesive,
Benzotriazole type ultraviolet absorber and benzophenone type ultraviolet absorber;
An ultraviolet-absorbing adhesive composition comprising ethyl acetate. The ultraviolet-absorbing adhesive composition according to claim 11, wherein the adhesive is a two-part curable adhesive.

Images