JP6797095B2 - Transparent laminate - Google Patents

Description

The present invention relates to a transparent laminate.

In the fields of cosmetics, pharmaceuticals, foods, etc., transparent containers that allow the contents to be visually recognized from the outside may be used. When a transparent container is used, it is desirable to impart UV absorbing ability to the container material in order to protect the contents from UV rays.

In this regard, 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 an ultraviolet stabilizer is included in the polyester resin composition layer constituting one layer of the laminate for a laminate tube. Patent Document 3 describes that an unstretched thermoplastic resin layer containing an ultraviolet 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 layer of a laminate that is a material for a transparent container.

In addition, Patent Document 4 describes a laminated film in which organic ultraviolet absorber migration blocking layers made of an oxygen atom-containing thermoplastic resin are 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 technique relates to forming an ultraviolet absorbing layer by a coating method.

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

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

When an organic UV absorber is used, there is a concern about bleeding out of the UV absorber. If the ultraviolet absorber bleeds out due to aging, heating, or the like, the adhesion of the ink deteriorates when printing is performed on the container, and the lamination strength may be impaired when the dry laminating process is performed.

In this regard, according to the technique 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 is a factor of increasing the cost of the container because the manufacturing method thereof is complicated.

On the other hand, when an inorganic ultraviolet absorber is used, there is little risk 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 obtained laminate.

In the technique described in Patent Document 5 for forming an ultraviolet absorbing layer by a coating method, it is considered difficult to set conditions for exhibiting the ultraviolet absorbing function because the thickness of the coating layer is limited. Be done. Patent Document 5 also does not have a specific guideline regarding the type and content of the ultraviolet absorber contained in the coating liquid. In addition, most of the printing methods adopted when the transparent container is a laminated tube are UV printing. Addition of an ultraviolet absorber to the UV ink used for UV printing can cause poor curing of the printing 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 ray blocking function.

The present invention is as follows.

[1] The outer layer, the adhesive layer, and the inner layer are provided in this order.
The adhesive layer contains a benzotriazole-based UV absorber and a benzophenone-based UV absorber.
Transparent laminate.
[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 the 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 [1].
[3] The transparent laminate according to [1] or [2], wherein the outer layer and the inner layer are layers having a single-layer structure or a multi-layer structure containing an LLDPE film, respectively.
[4] The transparent laminate according to [3], wherein the inner layer is a layer having a multi-layer structure including a PET layer.
[5] From a cured product of a two-component curable UV-absorbing adhesive composition, wherein the adhesive layer contains a two-component curable adhesive and a benzotriazole-based UV absorber and a benzophenone-based UV absorber. The transparent laminate according to any one of [1] to [4], which is a constituent layer.
[6] The transparent laminate according to [5], wherein the curing agent of the two-component curing type adhesive is an aliphatic curing agent.
[7] When the ultraviolet transmittance of the transparent laminate is measured under the conditions of a measurement wavelength of 200 nm to 500 nm, a scan speed of 600 nm / min, and a slit width of 4.00 nm, ultraviolet transmission at wavelengths of 360 nmm, 330 nm, and 270 nm is performed. The transparent laminate according to any one of [1] to [6], wherein the rate is 5.0% or less.
[8] The transparent laminate according to any one of [1] to [7] used for a tube container.
[9] A method for producing a transparent laminate, which comprises laminating the outer layer and the inner layer via an adhesive layer containing a benzotriazole-based ultraviolet absorber and a benzophenone-based ultraviolet absorber.
[10] A two-component curable UV-absorbing adhesive composition containing a two-component curable adhesive and a benzotriazole-based UV absorber and a benzophenone-based UV absorber is used for the outer layer and the inner layer. The method for producing a transparent laminate according to [9], which is laminated by dry lamination.
[11] Adhesive and
Benzotriazole-based UV absorbers and benzophenone-based UV absorbers,
A UV-absorbing adhesive composition comprising ethyl acetate.
[12] The ultraviolet-absorbing adhesive composition according to [11], wherein the adhesive is a two-component curable adhesive.

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

FIG. 1 is a schematic cross-sectional view for explaining the layer structure of the transparent laminate of the present invention. FIG. 2 is an ultraviolet transmittance chart of the transparent laminate samples obtained in Comparative Examples 1 to 3, respectively. FIG. 3 is an ultraviolet transmittance chart of the transparent laminate sample obtained in Example 5. FIG. 4A is an ultraviolet transmittance chart before wiping the surface of the transparent laminate obtained in Example 13 with ethanol, and FIG. 4B is a chart of the ultraviolet transmittance of the transparent laminate obtained by wiping the surface with ethanol. It is a later ultraviolet transmittance chart. FIG. 5 (a) is an ultraviolet transmittance chart before wiping the back surface of the transparent laminate obtained in Example 13 with ethanol, and FIG. 5 (b) shows the back surface of the transparent laminate wiped with ethanol. It is a later ultraviolet transmittance chart.

<Transparent laminate>
The transparent laminate of the present invention is
It has an outer layer, an adhesive layer, and an inner layer in this order.
The adhesive layer contains a benzotriazole-based UV absorber and a benzophenone-based UV absorber.

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

The adhesive layer in the transparent laminate is often formed by applying the adhesive material as a solution-like adhesive composition dissolved in a solvent. Since there is a limit to the amount of this adhesive composition that can be applied, the resulting adhesive layer is thin, and therefore the absolute amount of UV absorber that can be contained 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 ultraviolet light in a wide range.

An ultraviolet absorber that can block the transmission of a wide range of UV light and is soluble in the solvent used in the adhesive composition, or such, in a small amount that can be contained in the thin adhesive layer. No combination of UV absorbers is known in the prior art.

The present invention has succeeded in simultaneously satisfying all of the above requirements by including two types of ultraviolet absorbers, a benzotriazole-based ultraviolet absorber and a benzophenone-based ultraviolet absorber, in the adhesive layer of 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 may be a single-layer structure or a multi-layer structure including a transparent resin layer having a heat-sealing property.

When a container is manufactured using the transparent laminate of the present invention, the sheet-shaped transparent laminate is rolled into a tubular shape to overlap the ends of the outer layer and the inner layer, and the overlapping portions are heat-sealed to form a tubular body. I have something to do. At this time, since the outer layer and the inner layer are heat-sealed so as to be fused, the transparent resin having the heat-sealing property constituting the outer layer is preferably one having a good heat-sealing property with the inner layer resin.

Examples of the transparent resin layer, particularly the transparent resin having the heat-sealing property as described above, include polyethylene (PE) and the like. Specifically, the 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 a heat-sealing property may be a sheet or film of these resins, or a coating film formed by using a composition containing these resins, and may be an LLDPE film in particular. Therefore, the outer layer may be a single-layer structure or a multi-layer structure including an LLDPE film.

The outer layer of the transparent laminate of the present invention may have, for example, a polyester layer, an inorganic vapor deposition layer, or the like, 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 UV absorber and a benzophenone-based UV absorber.

The adhesive layer in the transparent laminate of the present invention contains both a benzotriazole-based ultraviolet absorber and a benzophenone-based ultraviolet absorber, and is arbitrary as long as 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-based adhesive, an ethylene-vinyl acetate copolymer-based adhesive, an acrylic resin-based adhesive, a vinyl chloride resin-based adhesive, a chloroprene rubber-based adhesive, or the like. ..

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 not have an aromatic ring so that the resulting transparent laminate is not discolored by irradiation with ultraviolet light. For example, the curing agent of the two-component reaction type adhesive may be an aliphatic curing agent.

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

The adhesive layer in the transparent laminate of the present invention has an amount of the adhesive layer per unit area of the transparent laminate of 2.0 g / m ² or more, 2 or more, from the viewpoint of sufficiently increasing the lamination strength between 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 ensuring the laminate strength, 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 compounds include, for example, 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-5-t-butylphenyl) benzotriazole, 2- ( 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 or the like.

The halide of the hydroxyphenyl-substituted benzotriazole compound is, for example, 2- (2-hydroxy-3-t-butyl-5-methylphenyl) -5-chlorobenzotriazole (also known as 2- (5-chloro-2H-benzo). Triazole-2-yl) -6-t-butyl-4-methylphenol), 2- (2-hydroxy-3,5-di-t-butylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy -3- (2-Methylpentane-2-yl) -5- (2-methylbutane-2-yl) phenyl) -5-chlorobenzotriazole, 2- (2-hydroxy-3-t-butyl-5- (2-hydroxy-3-t-butyl-5-yl) 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. It may be 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 or more and 400 nm or less, which is insufficiently blocked by the benzophenone-based ultraviolet absorber described later. Ultraviolet light and ultraviolet light having a wavelength of around 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. In the adhesive layer in which the amount of the benzotriazole-based ultraviolet absorber used is not excessive, the outer layer and the inner layer can be laminated with high adhesive strength, and the lamination 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 when the balance between the UV blocking property and the laminating strength is considered to the maximum. It may be in the range of .28 g / m ² or less.

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

The hydroxy-substituted benzophenone-based ultraviolet absorbers include, for example, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, and 2-hydroxy-4-n-octoxybenzophenone (also known as [2]. -Hydroxy-4- (octyloxy) phenyl] (phenyl) metanone), 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'-dimethoxybenzophenone, 2,2', 4,4'-tetrahydroxybenzophenone and the like.

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 It may be / 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 having a wavelength of around 330 nm, which is insufficiently blocked by the benzotriazole-based ultraviolet absorber.

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 It may be / 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 ² or less. In the adhesive layer in which the amount of the benzophenone-based ultraviolet absorber used is not excessive, the outer layer and the inner layer can be laminated with high adhesive strength, and the lamination 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 when the balance between the UV blocking property and the laminate strength is considered to the maximum. It may be in the range of 76 g / m ² or less.

(Combined use of benzotriazole-based UV absorber and benzophenone-based UV absorber)
The total amount of the benzotriazole-based ultraviolet absorber and the benzophenone-based ultraviolet absorber used in the adhesive layer is, for example, 0.30 g / m ² or more, 0.35 g / m ² or more, 0 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.

The ultraviolet absorber in the adhesive layer is preferable in order to make the lamination strength between the outer layer and the inner layer of the transparent laminate sufficiently high and to obtain a transparent laminate exhibiting a high degree of ultraviolet absorption ability and a high degree of transparency. 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 It may be used in combination with a benzophenone-based 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 contents of each of the benzotriazole-based ultraviolet absorber and the benzophenone-based ultraviolet absorber in the transparent laminate can be obtained by immersing the transparent laminate sample in a solvent to extract the ultraviolet absorber and concentrating it as necessary. It can be quantified by measuring the liquid chromatography of the obtained extract. The measurement result of liquid chromatography may be converted into a value per unit area of the original transparent laminated sample. As the extraction solvent, for example, chloroform is suitable.

[Inner layer]
The inner layer in the transparent laminate of the present invention may be a single-layer structure or a multi-layer structure including a transparent resin layer.

When the container is manufactured using the transparent laminate of the present invention, if it is planned to fuse the inner layer and the outer layer, the inner layer may include a transparent resin layer having a heat-sealing property, and the outer layer resin and the outer layer resin may be included. It may contain a transparent resin layer having a good heat-sealing property.

Examples of the transparent resin constituting the inner layer include polyethylene, and for example, LDPE, LLDPE, MDPE, HDPE and the like may be appropriately selected and used. The transparent resin constituting the inner layer may be a sheet or film of these resins, or a coating film formed by using a composition containing these resins, and may be an LLDPE film in particular. Therefore, the inner layer may be a single-layer structure or a multi-layer structure including an LLDPE film.

The inner layer of the transparent laminate of the present invention may have a transparent resin layer as described above, particularly a base material layer that imparts rigidity to the transparent laminate, in addition to 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 composed of 6-nylon, 6,6-nylon and the like.

From the viewpoint of effectively exerting the effect of imparting rigidity, 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 material layer is made excessively thick, it is disadvantageous in terms of cost effectiveness, and from the viewpoint of avoiding an adverse effect on side seam formation at the time of sealing, the thickness of the base material layer is, 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, 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 includes the base material layer, these thicknesses are values including the thickness of the base material layer.

[Print layer]
The transparent laminate of the present invention may include a printing layer, if necessary. The printing layer may include, for example, a product name, description, precautions, etc. of the contents, and a printed pattern such as a design for stimulating purchasing motivation. The print layer may be arranged on either the outer layer or the inner layer. When the outer layer and the inner layer are multi-layered, they may be arranged in any of these multi-layered layers. For example, the print layer may be arranged on the outermost surface of the inner layer opposite to the side in contact with the contents, and the outer layer may be adhered onto the print layer via the adhesive layer specified in the present invention. It is included in the scope of the present invention.

The print layer may be formed by using a known ink composition (for example, UV ink composition) and by an appropriate printing method such as offset printing, gravure printing, flexo printing, and letterpress printing.

<Manufacturing method of transparent laminate>
The transparent laminate of the present invention may be produced, for example, by a method including 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 absorber, desired ones may be selected and used from those exemplified above as the materials constituting the transparent laminate, respectively. When the outer layer or the inner layer has a multi-layer structure, it may be used after being laminated by an appropriate method such as melt extrusion lamination or dry lamination. Prior to the lamination when the outer layer or the inner layer has a different layer structure and the adhesion between the outer layer and the inner layer, an appropriate treatment such as a corona discharge treatment may be performed in advance on the processed surface of the layer.

The adhesive layer is on the outer and / or inner layers, eg, on the surface of both.
With adhesive,
Benzotriazole-based UV absorbers and benzophenone-based UV absorbers,
Formed by applying a UV-absorbing adhesive composition containing ethyl acetate, then laminating the outer and inner layers, then removing the solvent in the UV-absorbing adhesive composition and curing the adhesive. May be done.

The adhesive contained in the above-mentioned ultraviolet-absorbing adhesive composition may be a one-component type adhesive or a two-component type (two-component curable type) adhesive, and may be the adhesive exemplified above. A desired agent may be selected and used. The types and amounts of the benzotriazole-based ultraviolet absorber and the benzophenone-based ultraviolet absorber may also 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 content in the obtained 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% by weight. It may be used in an amount of% or less and 40% by weight or less.

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

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

Regarding the blocking property against ultraviolet light, the transparent laminate of the present invention is subjected to ultraviolet rays under the conditions of a measurement wavelength of 200 nm to 500 nm, a scan speed of 600 nm / min, and a slit width of 4.00 nm using an ultraviolet visible near infrared spectrophotometer. When the transmittance is measured, the ultraviolet transmittance at wavelengths of 360 nmm, 330 nm, and 270 nm may be 5.0% or less. The ultraviolet transmittance of the transparent laminate at 360 nm 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 particularly high blocking efficiency against ultraviolet light 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 property even when the outer layer and the inner layer are materials having no ultraviolet blocking property (for example, PE). In addition, PET, which is generally used as a laminate material, blocks ultraviolet light in a wavelength region of 300 nm or less well, but exhibits significant transmittance in a wavelength region of 320 nm or more. Since the transparent laminate of the present invention can efficiently block ultraviolet light of 360 nm or less even when the outer layer and the inner layer are composed of PET, the ultraviolet rays originally possessed by the material of the outer layer and the inner layer. The blocking range will be expanded.

Regarding the transparency to visible light, the haze measured according to JIS K 7105 for the transparent laminate of the present invention is, for example, 40% or less, 38% or less, 36% or less, 34% or less, 32% or less, or 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 an adhesive layer containing an ultraviolet absorber, the lamination strength between the two layers is very high. Specifically, for a test piece having a width of 15 mm produced from the transparent laminate of the present invention, the T-type peel strength measured in accordance with JIS K 6854 is 10.0 N / 15 mm or more and 12.0 N / 15 mm or more. It may be 13.0N / 15mm or more, 13.5N / 15mm or more, 14.0N / 15mm or more, 14.5N / 15mm or more, or 15N / 15mm or more.

<Use of transparent laminate>
The transparent laminate of the present invention may be used, for example, as a laminate tube container, a laminate packaging bag, or the like. Specifically, the transparent laminate of the present invention may be used as a laminate tube container for cosmetics, pharmaceuticals, foods and the like.

The laminated tube container may consist of a body portion, a mouth portion having a diameter smaller than the body portion, and a shoulder portion connecting the body portion and the mouth portion. The laminated tube container is, for example, a method in which the transparent laminate of the present invention is rolled into a tubular shape to form a tubular body portion and then welded to a separately manufactured shoulder portion and mouth portion, and the shoulder portion is formed by compression molding. It may be manufactured by an appropriate method including a method of simultaneously welding and welding the tubular body portion 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]
LLDPE1 (100): Made by Tamapoli Co., Ltd., linear low-density polyethylene, product name "SE620N", thickness 100 μm
LLDPE2 (80): Made by Toyobo Co., Ltd., linear low-density polyethylene, product name "LIX-NP L4102", thickness 80 μm
LDPE: Asahi Kasei Corporation, low density polyethylene, product name "Suntech-LD M1880E"
PET (12): Made by Unitika Ltd., biaxially stretched polyester film, product name "PETB", thickness 12 μm

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

[UV absorber]
LA-36: ADEKA Corporation, benzotriazole UV absorber, 2- (5-chloro-2H-benzotriazole-2-yl) -6-t-butyl-4-methylphenol, product name "ADEKA STAB LA-" 36 "
1413: Benzophenone-based UV absorber manufactured by ADEKA Corporation, [2-hydroxy-4- (octyloxy) phenyl] (phenyl) methanone, product name "ADEKA STUB 1413"

<Evaluation of UV transmittance>
[Comparative Examples 1 to 4 and Examples 1 to 8]
(1) Preparation of Ultraviolet Absorbent Adhesive Composition 10 g (nonvolatile content 5.5 g) of the adhesive (main agent) and 11.94 g of ethyl acetate were mixed to obtain Solution A. Each predetermined amount of the ultraviolet absorbers "LA-36" and "1413" was weighed and mixed with the solution A to obtain the solution B. Next, 2 g of an adhesive (curing agent) (1.2 g of non-volatile content) was mixed with Solution B to prepare a two-component curable UV-absorbing adhesive composition.

Here, each of the ultraviolet absorbers "LA-36" and "1413" has a solid content in the adhesive (that is, the total weight of the non-volatile content of the adhesive (main agent) and the adhesive (hardener)) of 100 weight. When the percentage was set to%, an amount having a ratio (% by weight) shown in the "weight ratio to adhesive" column of Table 1 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). ), An attempt was made to prepare an ultraviolet-absorbing adhesive composition, but the ultraviolet absorber was not completely dissolved, so no further experiments were conducted.

(2) Preparation of Transparent Laminated Two LLDPE1 (100) sheets were prepared, and one side of each was subjected to corona discharge treatment.

The ultraviolet-absorbing adhesive composition was applied on one of the LLDPE1 (100) corona discharge-treated surfaces by gravure coating at a solid content equivalent of 4.2 g / m ² , and the other was coated. It was bonded to the corona discharge-treated surface of LLDPE1 (100) and allowed to stand at 40 ° C. for 5 days (120 hours) to cure the adhesive, thereby obtaining a transparent laminate having the following layer structure.
LLDPE1 (100) / UV absorber-containing adhesive layer / LLDPE1 (100)

(3) Measurement of UV Absorbent Content The obtained transparent laminate was cut into a 10 cm × 10 cm square sheet as a sample. This sheet was shredded into substantially square pieces having a side of about 1 cm and immersed in chloroform to extract an ultraviolet absorber. After concentrating the extract under reduced pressure, liquid chromatography was performed to quantify the amount of the ultraviolet absorber contained in the extract and convert it into a value per unit area of the transparent laminate sample used for the measurement.

(4) Measurement of UV transmittance Using an ultraviolet-visible near-infrared spectrophotometer manufactured by Hitachi High-Tech Science Co., Ltd., product name "UH4150", the UV transmittance of the obtained transparent laminate sample was measured under the following conditions. It was measured. The ultraviolet transmittance at wavelengths of 360 nmm, 330 nm, and 270 nm at this time was adopted as an index of the transparency of the transparent laminate.
Measurement wavelength: 200 nm to 500 nm
Scan 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 in accordance with JIS K 7105 using a haze / transmittance / reflector manufactured by Murakami Color Technology Laboratory Co., Ltd. and the product name "HR100". ..

(6) Presentation of measurement results The UV 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 haze measurement results are shown in each transparent laminate. It is shown in Table 1 together with the content of the ultraviolet absorber in it. In addition, the ultraviolet transmittance charts of the transparent laminate samples of Comparative Examples 1 to 3 used as the basis for the numerical values of the ultraviolet transmittances at wavelengths of 360 nm, 330 nm, and 270 nm are shown in FIG. 2 of the transparent laminate sample of Example 5. The ultraviolet transmittance charts are shown in FIG. 3, respectively.
Although attachment of the ultraviolet transmittance charts of Examples 1 to 4 and Examples 6 to 8 is omitted, the numerical values of the ultraviolet transmittances in these examples in Table 1 are the values extracted from the corresponding ultraviolet transmittance charts, respectively. Is.

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

In the transparent laminate sample of Comparative Example 1 containing only the benzotriazole-based ultraviolet absorber "LA-36" as the ultraviolet absorber in the adhesive layer, the ultraviolet transmittance sharply decreased at a wavelength shorter than 400 nm, and was around 360 nm. The transmittance level reached almost no problem, but peaks with high transmittance were observed at wavelengths around 330 nm and 270 nm. Comparative example in which the amount of the benzotriazole-based ultraviolet absorber "LA-36" was increased to 7% by weight (corresponding to 0.34 g / m ² per unit area of the transparent laminate) with respect to the non-volatile content in the adhesive composition. In No. 4, as described above, the ultraviolet 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 containing only the benzophenone-based ultraviolet absorber "1413" as the ultraviolet absorber in the adhesive, a 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 peaks were observed in which the transmittance increased near 310 nm and 270 nm. Was done.

The ultraviolet transmittance of the transparent laminate sample of Comparative Example 3 in which the content of the benzophenone-based ultraviolet absorber "1413" in Comparative Example 2 was increased was decreased overall in the wavelength region shorter than 380 nm, but was around 360 nm. The level of transmittance was still high, and peaks with high transmittance were maintained near 310 nm and 270 nm.

On the other hand, the transparent laminate sample of Example 1 containing both the benzotriazole-based ultraviolet absorber "LA-36" and the benzophenone-based ultraviolet absorber "1413" as the ultraviolet absorber in the adhesive layer has a wavelength of 400 nm. The ultraviolet transmittance decreased sharply at shorter wavelengths, reached a problem-free transmittance level near 360 nm, and no increase peaks of transmittance were observed at wavelengths around 330 nm and 310 nm. A peak in which the ultraviolet transmittance slightly increased was confirmed around the wavelength of 270 nm, but this is not a problematic level. The ultraviolet transmittances at wavelengths of 360 nm, 330 nm, and 270 nm measured for the transparent laminate samples of Examples 2 to 8 all showed low values.

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

From the above, the embodiment of the present invention containing both the benzotriazole-based ultraviolet absorber and the benzophenone-based ultraviolet absorber in the adhesive layer exhibits high transparency to visible light and has a wavelength shorter than 360 nm. It was verified that it can absorb the ultraviolet rays in the region and reduce the ultraviolet transmittance in the region measured in this example to a level that does not cause any problem.

<Evaluation of laminate strength>
[Comparative Example 5 and Examples 9 to 14]
(1) Preparation of Inner Layer (Base Laminate) An inner layer having a printed pattern having the following layer structure was prepared by the following procedure.
(Printed pattern) / LDPE (40) / PET (12) / Adhesive layer / LLDPE1 (100) / LDPE (70) / LLDPE1 (100)

One side of PET (12) was subjected to corona discharge treatment. LLDPE1 (100) is laminated on the corona discharge-treated surface of the PET (12) via a two-component reaction-curing dry laminate adhesive layer, and the laminate A (PET (12) / adhesive layer / LLDPE1 (100). )) Was obtained.

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

The molten LDPE is laminated on the PET (12) side surface of the laminate B via an anchor coat layer to form an LPDE layer (LDPE (40)) having a thickness of 40 μm, which is formed as a laminate C (LDPE (40)). / PET (12) / adhesive layer / LLDPE1 (100) / LDPE (70) / LLDPE1 (100)) was obtained.

Further, by printing a pattern on a part of the surface of the laminated body C on the LDPE (40) side using UV ink, a base having a printed pattern having a 7-layer structure including a layer of the printed pattern. A laminate was obtained.

(2) Preparation of UV Absorbent Adhesive Composition The amounts of UV absorbers "LA-36" and "1413" used are "Adhesive" in Table 2 when the solid content in the adhesive is 100% by weight. In the same manner as in [Comparative Examples 1 to 4 and Examples 1 to 8], except that the amount is the ratio (% by weight) shown in the "weight ratio to agent" column, the two-component curing type UV absorption An adhesive composition was prepared. The adhesive composition in Comparative Example 5 does not contain an ultraviolet absorber.

(3) Preparation of Transparent Laminate A UV-absorbing adhesive composition is applied to the surface of the base laminate on the LDPE (40) side having a printed pattern by gravure coating to obtain a solid content of 4.2 g / m ² . A transparent laminate having the following layer structure was obtained by applying the coating amount and bonding with LLDPE2 (80).
LLDPE2 (80) / UV absorber-containing adhesive layer / (printed pattern) / LDPE (40) / PET (12) / adhesive layer / LLDPE1 (100) / LDPE (70) / LLDPE1 (100)

(4) Measurement of Laminate Strength A strip-shaped test piece having a width of 15 mm and a length of 100 mm is cut out from the transparent laminate obtained above with the MD direction as the major axis, and attached via an ultraviolet absorber-containing adhesive layer. The combined LLDPE2 (80) layer and LDPE (40) layer were peeled off, and the T-type peeling 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: Toyo Seiki Seisakusho Co., Ltd., strograph, product name "VES10"
Grab movement speed: 300 mm / min

(5) Measurement of UV Absorbent Content 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 Table 2 shows the measurement results of the laminate strength obtained for the transparent laminate samples of Comparative Example 5 and Examples 9 to 14 together with the content of the ultraviolet absorber in each transparent laminate. Indicated.

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

<Check for bleed-out>
In the above transparent laminate, the presence or absence of bleed-out of the ultraviolet absorber was confirmed.
When the front surface and the back surface of the transparent laminate obtained in Example 13 were wiped with ethanol, the ultraviolet transmittance before and after wiping was measured. This measurement was performed using a UV-VIS spectrophotometer UH4150 manufactured by Hitachi High-Tech Science under the following conditions.
Measurement wavelength: 210nm-600nm
Scan speed: 600 nm / min Sampling interval: 1 nm
Slit width: 4.00 nm

The obtained UV transmittance charts are shown in FIGS. 4 and 5. FIG. 4A is an ultraviolet transmittance chart before wiping the surface of the transparent laminate obtained in Example 13 with ethanol, and FIG. 4B is a chart of the ultraviolet transmittance of the transparent laminate obtained by wiping the surface with ethanol. It is a later ultraviolet transmittance chart. FIG. 5 (a) is an ultraviolet transmittance chart before wiping the back surface of the transparent laminate obtained in Example 13 with ethanol, and FIG. 5 (b) shows the back surface of the transparent laminate wiped with ethanol. It is a later ultraviolet transmittance chart.

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

<Measurement of haze>
The haze of the transparent portion of the transparent laminate produced in Example 13 that does not have a printed pattern is JIS using a haze / transmittance / reflector manufactured by Murakami Color Technology Laboratory Co., Ltd., and the product name "HR100". Measured according to K 7105. As shown in Table 3, the haze of this transparent laminated sample was 27.9%, and it was confirmed that the contents were transparent so that the contents could be visually recognized when the container was used.

1 outer layer 2 adhesive layer 3 inner layer

Claims (9)

It has an outer layer, an adhesive layer, and an inner layer in this order.
The adhesive layer is observed containing a benzotriazole ultraviolet absorbers and benzophenone-based ultraviolet absorber, and,
Used for tube containers ,
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 the outer layer and the inner layer are layers having a single-layer structure or a multi-layer structure containing an LLDPE film, respectively. The transparent laminate according to claim 3, wherein the inner layer is a layer having a multi-layer structure including a PET layer. The adhesive layer is composed of a cured product of a two-component curable UV-absorbing adhesive composition containing a two-component curable adhesive and 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 type adhesive is an aliphatic curing agent. When the ultraviolet transmittance of the transparent laminate is measured under the conditions of a measurement wavelength of 200 nm to 500 nm, a scan speed of 600 nm / min, and a slit width of 4.00 nm, the ultraviolet transmittance at wavelengths of 360 nmm, 330 nm, and 270 nm is any. The transparent laminate according to any one of claims 1 to 6, wherein the amount is 5.0% or less. The method for producing a transparent laminate according to claim 1.
Including laminating the outer layer and the inner layer via an adhesive layer containing a benzotriazole-based UV absorber and a benzophenone-based UV absorber.
A method for manufacturing a transparent laminate. The outer layer and the inner layer are dry-laminated using a two-component curable UV-absorbing adhesive composition containing a two-component curable adhesive and a benzotriazole-based UV absorber and a benzophenone-based UV absorber. The method for producing a transparent laminate according to claim 8 , wherein the transparent laminate is laminated.

Images