JP2003200966A - Light-shielding shrink film - Google Patents

Abstract

(57) [Summary] A light-shielding property having excellent light-shielding properties such that the transmittance of ultraviolet rays is 35% or less and the transmittance of visible rays is 3% or less, and excellent white opacity after printing. Provide shrink film. A light-shielding shrink film comprising a heat-shrinkable synthetic resin film and a white ink layer entirely solid printed thereon and a white ink layer containing an aluminum paste entirely solid printed are sequentially laminated. By doing so, the above problem was solved.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a light-shielding shrink film. More specifically, by providing a layer of a heat-shrinkable synthetic resin film in which a white ink layer for full solid printing and a white ink layer containing an aluminum paste for full solid printing are sequentially laminated, it is possible to block light in the visible and ultraviolet light regions. And a light-shielding shrink film having excellent whiteness and hiding power (whiteness) after printing.

[0002]

2. Description of the Related Art Conventionally, for filling and packaging milk / milk drink, beer, vitamin drink, juice, carbonated drink, water, drinking water such as tea, oil, seasoning, and other various liquid foods, Various types of plastic bottles, glass bottles, metal cans, etc. (hereinafter referred to as "containers") have been developed. Then, on the surface of these containers, for the purpose of protecting the containers, bundling, labeling, etc., quickly or partially covering all or part of the mouth, shoulder, body, etc. of the containers, or
A shrink film (hereinafter, also referred to as “heat-shrinkable film”) is known as a packaging material for binding. As a shrink wrapping method, for example, there is known a method in which a tubular or bag-shaped film is subjected to primary wrapping with some allowance, and then the film is shrunk to the outer peripheral surface of the container by hot air, steam or the like. . In addition, the film is wrapped in a tensioned state to some extent, the end of the film is folded into the bottom of the container, and the folded part is primary-wrapped by self-adhesion or thermal fusion of the films, and then shrink-treated to loosen the film or Methods such as stretch shrink for removing wrinkles are known. Since the shrink wrapping can fit into any shape container such as a square shape, a round shape, and a gourd shape, the shape of the container can be widely selected. Further, since the shrink film and the container are not directly adhered, they can be completely separated from the container. Therefore, from the perspective of recycling, shrink film, which can be separated from the container, is expected to increase in demand in the future.
As shrink wrap, colorless shrink film or printed shrink film to add the function of displaying the product name, manufacturer name, contents, and design to the entire surface and sealing part of these containers is used. Packaging of containers is also practiced. Further, in order to shield the contents such as beer that need a light-shielding property from external light, it is also possible to wrap the entire container with a shrink film having a light-shielding function by using a colored shrink film. ing.

[0003]

The shrink film has a structure in which a solid ink white ink layer and a solid ink gold ink layer are sequentially stacked on a print layer of a heat-shrinkable synthetic resin film. As a technique for imparting a light-shielding property to the shrink film, Japanese Patent Application Laid-Open No. 2001-212
There is No. 2 publication. However, when a white ink layer is separately provided and stacked on the shrink film, the appearance becomes grayish and the whiteness (white concealing property) becomes low, and the product such as milk drink in which the white image is important in the content On the other hand, there is a problem in appearance. Japanese Patent Laid-Open No. 11-288221 discloses a technique for imparting a light-shielding property to a shrink film by using a colored film made of synthetic resin (an opaque polyethylene film colored in orange or the like). However, as in JP-A-2001-2122, when a white ink layer is separately provided on the shrink film and the layers are overlapped with each other, the appearance becomes grayish and the whiteness (white hiding property) becomes low. , There is a cosmetic problem.

[0004]

In order to solve the above-mentioned problems, the inventors of the present invention have conducted extensive studies and as a result, as a result, on a heat-shrinkable synthetic resin film, a solid ink white ink layer and an entirely solid ink layer were formed. By providing a layer in which white ink layers containing aluminum paste for printing are sequentially laminated, a light-shielding shrink film having excellent light-shielding properties in the visible light and ultraviolet light regions and excellent white hiding property (whiteness) is found. Came to. The present invention provides a light-shielding shrink film characterized in that a white solid ink layer for full printing and a white ink layer containing aluminum paste for full printing are sequentially stacked on a heat-shrinkable synthetic resin film. Is to provide. The light-shrinkable shrink film according to claim 1, wherein in the white ink layer containing the solid-printed aluminum paste, the amount of aluminum paste in the ink is 10% by weight or less. Can also be provided. In addition, the transmittance of visible light of 380 to 780 nm is 35% or less, the transmittance of ultraviolet light of 300 to 380 nm is 3% or less, and the whiteness (white hiding degree) is 50% or more in L * value. It is also possible to provide the light-shielding shrink film according to any one of claims 1 and 2.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. FIG. 1 is a sectional view showing an example of the light-shielding shrink film 10 of the present invention. Light-shielding shrink film 1
0 is composed of a film which is a heat-shrinkable synthetic resin film 1 / a pattern printing layer 2 / a white ink (all solid printing) layer 3 / a white ink (all solid printing) layer 4 containing an aluminum paste.

In the present invention, the heat-shrinkable synthetic resin film 1 constituting the light-shielding shrink film 10 according to the present invention is not particularly limited as long as it has printability, and for example, a heat-shrinkable polyethylene terephthalate film. , Polystyrene film, polypropylene film, low density polyethylene film, medium density polyethylene film, high density polyethylene film, low density linear polyethylene film, cyclic polyolefin film,
Polyethylene film produced from a resin such as ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-acrylic acid copolymer, ethylene-methyl acrylate copolymer, chlorinated polyethylene, A modified polyolefin film formed from a resin such as chlorinated polypropylene, a film formed from a vinyl chloride-vinyl acetate copolymer resin, an acrylic resin-based film, or the like can be used. The heat-shrinkable synthetic resin film 1 may be colored transparently or opaquely with a colorant such as a pigment. As the heat-shrinkable synthetic resin film 1, either a uniaxially stretched film or a biaxially stretched film can be used. Then, the heat shrinkable synthetic resin film 1 is uniaxially stretched in a direction perpendicular to the flow of the heat shrinkable synthetic resin film 1 using a tenter method or the like, and the heat shrinkage rate in the perpendicular direction is 70 to 90 ° C. for 10 seconds. And up to 4
It is possible to use a heat-shrinkable synthetic resin film produced by adjusting so as to be 0%. Here, the thermal shrinkage is a value having a meaning of (dimension before heating-dimension after heating) / (dimension before heating) × 100. Heat-shrinkable synthetic resin film 1
The thickness of the is not particularly limited, heat resistance, rigidity,
Properly selected within a range that does not impair mechanical suitability, appearance, etc.,
5 to 90 μm is preferable, and 9 to 70 μm is desirable.

Light-shielding shrink film 1 according to the present invention
As the printed pattern layer 2 constituting 0, a pattern is formed on the entire surface of the heat-shrinkable synthetic resin film 1 or partially by using a known printing technique such as gravure printing, flexographic printing, offset printing or the like. Is. The ink used for the printed pattern layer 2 is a heat-shrinkable synthetic resin film 1
Generally used inks that have adhesiveness and have the required resistance can be used. It is preferable to print with a gravure ink, which is an ink having high heat resistance. In the present invention, it is preferable that the printed pattern layer 2 is not provided on both ends of the heat-shrinkable synthetic resin film 1 in the case of manufacturing a tubular body described later. An OP varnish layer may be provided on the printed pattern layer 2 for the purpose of protecting it from damage such as rubbing due to external force. The thickness of the printed pattern layer 2 is not particularly limited, but is preferably about 1 to 10 μm, and more preferably 2 to 5 μm.

Light-shielding shrink film 1 according to the present invention
The white ink used for the white ink (entire solid printing) layer 3 constituting 0 is a white ink that has adhesiveness with the heat-shrinkable synthetic resin film 1 and the printed pattern layer 2 and has necessary resistance. Can be used. White ink (solid printing) layer 3
The white ink used for is to use conc type white ink in order to improve the white hiding property, or
Overprinting with white ink is desirable. The thickness of the white ink (solid printing) layer 3 is not particularly limited, but is preferably about 1 to 8 μm, and more preferably 2 to 5 μm.

Light-shielding shrink film 1 according to the present invention
The white ink used in the white ink (entire solid printing) layer 4 containing the aluminum paste constituting 0 is adhesive to the white ink (entire solid printing) layer 3 and has a necessary resistance white. Other than being ink, 380-78
The transmittance of visible light of 0 nm is 35% or less, 300 to 3
It is necessary to use an ink containing a pigment having a light-shielding property, which has a transmittance of ultraviolet rays of 80 nm of 3% or less. An aluminum paste can be mentioned as such a pigment. As the content of the aluminum paste, white ink of 10% by weight or less is necessary, and it is desirable to use white ink of 1 to 5% by weight or less. When the content of the aluminum paste exceeds 10% by weight, the light-shielding property is improved, but the white hiding property is insufficient, which is not preferable.

In the light-shielding shrink film 10 of the present invention, the heat-shrinkable synthetic resin film 1 may include, if necessary, a lubricant, a filler, a heat stabilizer, an antioxidant, an ultraviolet absorber, an antistatic agent, a hardener. You may add various additives, such as a combustion agent and a coloring agent. On the surface of the heat-shrinkable synthetic resin film 1,
In order to improve printability, conventional surface treatment such as corona discharge treatment, plasma treatment, flame treatment and acid treatment may be applied.

A method of manufacturing the light-shielding shrink label 20 using the light-shielding shrink film 10 according to the present invention manufactured as described above will be specifically described.

FIG. 2 is a schematic perspective view showing the state of the cylindrical body of the light-tight shrink label 20 according to the present invention. In the present invention, as shown in FIG. 2, the light-shielding shrink film 10 is (inside the container) heat-shrinkable synthetic resin film 1 / thin metal layer 2 / adhesive layer 3 for lamination / printing layer 4 / heat shrinkage. -Like synthetic resin film 5 (outside the container) so that the lower end 2 is the both ends thereof
a and the upper end portion 2b are overlapped, and then, the sealing portion 21 is formed by heat-sealing or pasting with an adhesive agent using the overlapping portion of the end portion as a joint portion to form a tubular body. The light-shielding shrink label 20 made of is manufactured. The light-tight shrink label 20
A tube-shaped one may be used.

FIG. 3 is an overall view of a light-tight shrink package 30 showing an embodiment of a mounting form according to the present invention. In the present invention, as shown in FIG. 3, for example, the tubular body of the light-shielding shrink label 20 manufactured above is supplied to, for example, an automatic label mounting device and cut into a required length, and then, for example, the contents are Is fitted to the outer surface of the container 32, and then the container 32 is passed through a shrink tunnel (not shown) to obtain a predetermined temperature (for example, about 80 to 200 ° C.).
Of the heat-shrinkable shrink label 20 in the circumferential direction by applying radiant heat such as steam or steam that is heated by the hot air, steam and steam formed by condensation of the steam to the container 3
The light-shielding shrink label 20 covers from the upper end portion 3a to the lower end portion 3b, and the outer peripheral edge of the upper surface of the closing body 35 is also covered with the light-shielding shrink label 20. That is, the light-tight shrink label 20 covers the entire periphery of the container 32 and also covers the periphery of the closing body 35.
Thus, the light-shielding shrink packaging body 30 provided with the light-shielding shrink label 20 can be manufactured. The perforations 6 can be provided by, for example, a method of pressing a disc-shaped blade having a cut portion and a non-cut portion repeatedly formed around it. Further, the perforation 6 is a step of manufacturing the shrink label 20 made of a tubular body,
That is, it can be performed at an appropriate stage among the shrink film cutting step, the tube attaching step, and the shrink label cutting step.

Examples of the article (container) 32 to be wrapped with the light-shielding shrink film 10 of the present invention include containers such as plastic containers and glass containers. As the resin that constitutes the plastic container,
For example, vinyl polymers such as olefin polymers such as polypropylene and styrene polymers such as polystyrene,
Examples thereof include polyester and vinyl chloride resin. The resin is a foamed resin (for example, Styrofoam resin)
May be

As shown in FIG. 3, the container 32 has a body portion 33 formed on the lower side thereof, and a mouth portion 35 having a diameter smaller than that of the body portion 33 is formed above the body portion 33. The mouth portion 34 is formed in a tapered shape whose diameter gradually decreases toward the upper opening. The opening that opens above the mouth 34 is closed by a closing body 36 such as a crown or a screw cap.

The contents of the container 32 include beer,
Vitamin drink, milk / milk drink, juice, carbonated drink, water,
Examples thereof include drinking water such as tea, oils and fats, seasonings, and various liquid foods.

In the present invention, as shown in FIG. 3, the light-tight shrink label 20 manufactured as described above is formed into a full-shrink shape in which it is attached to the entire container 32 such as a plastic bottle or a glass bottle. By using the packaging body 30 in which the container 32 covered with the container is filled with the contents such as milk and dairy products that particularly need a light-shielding property, the white ink layer is separately provided and the appearance is grayed. It is possible to obtain a packaged product which is excellent in light-shielding properties in the visible light and ultraviolet light regions and is also excellent in designability without lowering the white hiding property. In addition,
The above example illustrates one example of the light-shielding shrink film 10 according to the present invention, the light-shielding shrink label 20 using the same, and the package 30 thereof.
The present invention is not limited thereby.

[0018]

EXAMPLES The present invention will be described below with reference to examples.

(Example 1) Heat-shrinkable synthetic resin film 1
For this, a polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., S7561) having a thickness of 45 μm was prepared.

On the above-mentioned heat-shrinkable synthetic resin film 1, a pattern printing layer 2 made of NT-Hiramic indigo (manufactured by Dainichiseika Co., Ltd.), a gravure plate having a plate depth of 28 μm and a line number of 175 lines was used. Printed.

On the picture pattern printing layer 2 as a white ink (solid printing) layer 3, NT-Hyramic Conc White (manufactured by Dainichiseika Co., Ltd.), plate depth 28 μm, line number 1
Gravure printing was performed by using a 75-line halftone plate and two times of overprinting, which was solid printing.

On the above-mentioned white ink (entire solid printing) layer 3, a white ink (entire solid printing) layer 4 containing an aluminum paste is used as an NT-high ramic conc white (manufactured by Dainichiseika Co., Ltd., aluminum paste). Content: 1% by weight)
Then, solid printing gravure printing was performed using a halftone plate having a plate depth of 28 μm and a number of lines of 175 lines. As a result, the light-shielding shrink film 10 of Example 1 comprising a polyethylene terephthalate film / a pattern printing layer / a white ink (solid printing twice) / white ink (aluminum paste content: 1% by weight) a solid printing layer was prepared. Obtained.

Thereafter, the light-shielding shrink film 10 obtained as described above is cut into a label sheet having a desired size, and (the outside of the container) a polyethylene terephthalate film / a pattern printing layer / a white ink (a solid ink on the whole surface). (2 times printing) layer / white ink (aluminum paste content: 1% by weight) Overlap both ends of the light-tight shrink film 10 so as to form a solid printing layer (inside the container), and seal the welded portion. It was heat-bonded to form a cylindrical body.

Next, the cylindrical light-tight shrink label 20
Is supplied to an automatic label attachment device, cut into a required length, and then fitted on the outer surface of a polyester bottle filled and packed with contents, and the light-tight shrink label 20 is heated with a steam heater at 90 ° C. for 10 seconds. I went through the shrink tunnel. As a result, the light-shielding shrink label 20 is provided on the entire part from the mouth to the bottom of the bottle body, and
Light-shrinkable shrink wrap 3 in the form of full shrink
I got 0.

(Example 2) Heat-shrinkable synthetic resin film 1
For this, a polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., S7561) having a thickness of 45 μm was prepared.

On the above-mentioned heat-shrinkable synthetic resin 1, as a pattern printing layer 2, Daiekoro Indigo (manufactured by Dainichiseika Co., Ltd.),
Gravure printing was performed using a halftone plate having a plate depth of 28 μm and a number of lines of 175 lines.

On the above-mentioned picture pattern printing layer 2, as a white ink (entirely solid printing) layer 3, New Dai Ecoro SR-
F701 white (manufactured by Dainichiseika Co., Ltd.), plate depth 28 μm,
Gravure printing was performed by two-time overprinting of solid printing using a halftone plate having 175 lines.

On the above-mentioned white ink (entire solid printing) layer 3, as a white ink (entire solid printing) layer 4 containing aluminum paste, New Dai Ecoro SR-F PET is used.
White (made by Dainichiseika Co., Ltd., aluminum paste content: 3
(% By weight) was subjected to solid printing gravure printing using a halftone plate having a plate depth of 28 μm and a number of lines of 175 lines. As a result, polyethylene terephthalate film / pattern printing layer / white ink (New Dai Ecoro SR-F701 white whole surface solid 2
A light-shielding shrink film 10 of Example 2 consisting of a solid printing layer / white ink (aluminum paste content: 3% by weight) layer / printing layer was obtained.

Thereafter, the light-shielding shrink film 10 obtained as described above is cut into a label sheet having a desired size, and (the outside of the container) a polyethylene terephthalate film / a pattern printing layer / a white ink (new dye). Ekoro SR-F701 white solid printing twice) layer / white ink (aluminum paste content: 3% by weight) Overlay both ends of the light-shielding shrink film 10 so as to form a solid printing layer (inside the container). The overlapped portion was heat-bonded with a welding seal to form a tubular body.

Next, the cylindrical light-tight shrink label 20
Is supplied to an automatic label attachment device, cut into a required length, and then fitted onto the outer surface of a polyester bottle filled with contents, and the light-tight shrink label 20 is heated with a steam heater at 90 ° C. for 10 seconds. I went through the shrink tunnel. As a result, the light-shielding shrink label 20 is provided on the entire portion of the bottle body from the mouth to the bottom, and
Light-shrinkable shrink wrap 3 in the form of full shrink
I got 0.

(Example 3) Heat-shrinkable synthetic resin film 1
As the above, a polystyrene film (DXL219-45 manufactured by Mitsubishi Plastics, Inc.) having a thickness of 60 μm was prepared.

On the heat-shrinkable synthetic resin 1, as a pattern printing layer 2, OSM indigo (manufactured by Dainichiseika Co., Ltd.) was used for gravure printing using a halftone plate having a plate depth of 28 μm and a number of lines of 175 lines. did.

On the above-mentioned pattern printing layer 2, as a white ink (solid printing) layer 3, OS-M66 Conc White (A-2) (manufactured by Dainichiseika Co., Ltd.), plate depth 28 μm,
Gravure printing was performed by two-time overprinting of solid printing using a halftone plate having 175 lines.

On the white ink (entire solid printing) layer 3 as the white ink (entire solid printing) layer 4 containing aluminum paste, OS-M66 concrete white (A-2)
(Manufactured by Dainichiseika Co., Ltd., aluminum paste content: 3% by weight), a solid printing gravure printing was performed using a halftone plate having a plate depth of 28 μm and a number of lines of 175 lines. As a result, polystyrene film / pattern printing layer / white ink (full surface 2
A light-shielding shrink film 10 of Example 3 comprising a whole printing solid layer / white ink layer (aluminum paste content: 3% by weight) was obtained.

Thereafter, the light-shielding shrink film 10 obtained as described above is cut into a label sheet having a desired size, and then the polystyrene film (outside the container) /
Both sides of the light-shielding shrink film 10 are overlapped so that a pattern printing layer / white ink (solid printing twice) layer / white ink (aluminum paste content: 3% by weight) becomes a solid printing layer (inside the container). Then, the overlapped portions were heat-bonded with a welding seal to form a tubular body.

Next, the cylindrical light-tight shrink label 20
Is supplied to an automatic label attachment device, cut into a required length, and then fitted on the outer surface of a polyester bottle filled and packed with contents, and the light-tight shrink label 20 is heated with a steam heater at 90 ° C. for 10 seconds. I went through the shrink tunnel. As a result, the light-shielding shrink label 20 is provided on the entire part from the mouth to the bottom of the bottle body, and
Light-shrinkable shrink wrap 3 in the form of full shrink
I got 0.

(Comparative Example 1) Heat-shrinkable synthetic resin film 1
As the above, a polystyrene film (DXL219-45 manufactured by Mitsubishi Plastics, Inc.) having a thickness of 60 μm was prepared.

On the heat-shrinkable synthetic resin 1, as a pattern printing layer 2, OSM indigo (manufactured by Dainichiseika Co., Ltd.) was used for gravure printing using a halftone plate having a plate depth of 28 μm and a number of lines of 175 lines. did.

On the above-mentioned pattern printing layer 2, as a white ink (solid printing) layer 3, OS-M66 Conc White (A-2) (manufactured by Dainichiseika Co., Ltd.) with a plate depth of 28 μm,
Gravure printing was performed by two-time overprinting of solid printing using a halftone plate having 175 lines.

On the white ink (entire solid printing) layer 3 as the silver ink (entire solid printing) layer 4, OS-
M120 silver (manufactured by Dainichiseika Co., Ltd.), plate depth 28 μm,
Gravure printing was performed on the entire surface using a halftone plate having 175 lines. As a result, a light-shielding shrink film of Comparative Example 1 consisting of a polystyrene film / a pattern printing layer / a white ink (all solid printing) layer / a silver ink (all solid printing) layer was obtained.

After that, the light-shielding shrink film 10 obtained as described above is cut into a label sheet having a desired size, and then the polystyrene film (outside the container) /
Both ends of the light-shielding shrink film 10 are overlapped with each other so that the pattern printing layer / white ink (entire solid printing) layer / silver ink (entire solid printing) layer (inside the container) are overlapped, and the overlapped portion is welded and sealed. It was heat bonded to form a tubular body.

Next, the cylindrical light-tight shrink label 20 is used.
Is supplied to an automatic label attachment device, cut into a required length, and then fitted on the outer surface of a polyester bottle filled and packed with contents, and the light-tight shrink label 20 is heated with a steam heater at 90 ° C. for 10 seconds. I went through the shrink tunnel. As a result, the light-shielding shrink label 20 was provided on the entire part from the mouth to the bottom of the bottle body, and Comparative Example 1
Light-shrinkable shrink wrap 3 in the form of full shrink
I got 0.

(Comparative Example 2) Heat-shrinkable synthetic resin film 1
As the above, a polystyrene film (DXL219-45 manufactured by Mitsubishi Plastics, Inc.) having a thickness of 60 μm was prepared.

On the heat-shrinkable synthetic resin 1, as a pattern printing layer 2, OSM indigo (manufactured by Dainichiseika Co., Ltd.) was used for gravure printing using a halftone plate having a plate depth of 28 μm and a number of lines of 175 lines. did.

On the above-mentioned pattern printing layer 2, as a white ink (solid printing) layer 3, OS-M66 concrete white (A-2) (manufactured by Dainichiseika Co., Ltd.) with a plate depth of 28 μm,
Gravure printing was performed by three-time overprinting, which was solid printing using a halftone plate having 175 lines.

As a result, Comparative Example 2 consisting of polystyrene film / pattern printing layer / white ink (solid printing) layer
To obtain a light-shielding shrink film.

After that, the light-shielding shrink film 10 obtained as described above is cut into a label sheet having a desired size, and then a polystyrene film /
Both ends of the light-shielding shrink film 10 are overlapped with each other so that a pattern printing layer / white ink (entire solid printing) layer / silver ink (entire solid printing) layer (inside the container) are formed, and the overlapping portion is welded and sealed. It was heat bonded to form a tubular body.

Next, the cylindrical light-tight shrink label 20
Is supplied to an automatic label attachment device, cut into a required length, and then fitted on the outer surface of a polyester bottle filled and packed with contents, and the light-tight shrink label 20 is heated with a steam heater at 90 ° C. for 10 seconds. I went through the shrink tunnel. As a result, the light-shielding shrink label 20 was provided on the entire part from the mouth to the bottom of the bottle body, and the comparative example 2
Light-shrinkable shrink wrap 3 in the form of full shrink
I got 0.

(Appropriateness of light-shielding property) Light-shielding shrink label laminate 10 obtained in Examples 1 to 3 and Comparative Examples 1 and 2.
Was cut into a size of 50 mm × 50 mm, and a spectrophotometer (manufactured by Shimadzu Corporation UV-2400 (PC) S
GLP) was used to measure the transmitted light in the 300 to 800 nm region. The measurement results are shown in Table 1 and FIG.

The following criteria were set, and the light-shielding property was evaluated in two stages of ◯ (good) and × (bad). The evaluation results are shown in Table 2. ◯: transmittance of 380 nm or less (ultraviolet region) is 3.
0% or less, the transmittance of 380 to 780 nm (visible light region) is 35.0% or less, and the light-shielding property is good ..... The transmittance of 380 nm or less is higher than 3.0%. ,
Moreover, the transmittance of 380 to 780 nm is higher than 35.0%, and the light shielding property is poor.

(Whiteness) With respect to the light-shielding shrink labels of Examples 1 to 3 and Comparative Examples 1 and 2 thus produced, the following criteria are set, and graded as ◯ (good) and × (bad). The whiteness was measured by using an SM color computer (SM-4CH type manufactured by Suga Test Instruments Co., Ltd.) for the total light transmittance.
Table 1 shows the L ^* values based on the color difference formula according to JIS-Z8730 "Color difference display method" L ^* , a ^* , b ^* color system.

The following criteria were set, and the whiteness was evaluated in two grades of ◯ (good) and × (bad). The evaluation results are shown in Table 2. ◯: L ^* value is 50% or less, good white concealing property in white solid printing, good appearance × ... L ^* value is greater than 50%, white concealing property in white solid printing Poor (gray and low whiteness), poor appearance

(Measurement result)

[Table 1]

(Evaluation result)

[Table 2]

As is clear from the results of FIG. 4 and Tables 1 and 2, the light-shielding shrink film of the present invention is very excellent in light-shielding property and good in white concealing property in white solid printing. Demonstrate the design.

[0056]

As described above, according to the light-shielding shrink film of the present invention, a full solid white ink layer and a full solid aluminum paste are provided on the pattern printing layer of the heat shrinkable synthetic resin film. It is possible to provide an excellent light-shielding shrink film capable of expressing a pattern print without being restricted by printing itself by providing a layer in which white ink layers containing are sequentially overlapped, because the white hiding property after printing is good. . Especially when the contents are milk, milk drink, etc., 380
It is required to have a light-shielding property in which the transmittance in the range of nm or less (ultraviolet region) is 3.0% or less, and the transmittance in the range of 380 to 780 nm (visible light region) is 35.0% or less. According to the light-shielding shrink label obtained from the light-shielding shrink film according to the present invention, in the case of the contents such as the above-mentioned milk and milk drink, it is excellent in protecting the contents from external light without degrading the contents. It is possible to provide a light-shielding shrink-wrapped product. Further, in the case of the contents such as the above-mentioned milk and milk drink, since the image of the conventional contents is white, it is required to have white concealability after printing, which is difficult to be given only by overprinting the white ink. By adopting a configuration in which a solid white ink layer and a solid white ink layer containing an aluminum paste are sequentially stacked,
It is possible to provide a light-shielding shrink-wrapped product that also has a design property.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a light-shielding shrink film of the present invention.

FIG. 2 is a schematic perspective view showing a state of a tubular body of the light-shielding shrink label 20 according to the present invention.

FIG. 3 is an overall view of a light-shielding shrink package 30 showing an embodiment of a mounting form according to the present invention.

FIG. 4 shows the measurement results of light transmittance at 300 to 780 nm of the light-shielding shrink films of Examples 1 to 3 and Comparative Examples 1 and 2.

[Explanation of symbols]

1 Heat-shrinkable synthetic resin film 2 Printed pattern layer 3 White ink (solid printing on the whole surface) 4 White ink containing aluminum paste (solid printing on the whole surface) 6 Perforations 6a Cutting part 6b Non-cutting part 10 Light-shielding shrink film 20 Cylindrical Light-shielding shrink label 2a composed of body 2 Lower end 2b Upper end 21 Laminating seal portion 30 Packaging body 31 Packaging material (light-shielding shrink label) 32 Container (attached object) 33 Body portion 34 Mouth portion 35 Closing body 3a Lower end portion 3b Upper end

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) // B29K 105: 02 B29K 105: 02 B29L 7:00 B29L 7:00 9:00 9:00 F term ( reference) 3E067 AA11 AB99 AC01 BA18A BB14A BB26A CA01 CA12 CA13 ED03 EE04 FB01 FC03 3E086 AB01 AD16 BA04 BA15 BA24 BB22 BB23 BB61 BB67 CA11 4F100 AB10C AK01A AK42 BA03 BA07 BA10A BA10C HB31B HB31C JA03A JD01 JD09 JL10B JL10C JN02 YY00C 4F210 AA24 AE01 AG01 AG03 RA03 RC02 RG02 RG04 RG27 RG35

Claims (3)

[Claims] 1. A light-shielding shrink film, comprising a heat-shrinkable synthetic resin film and a white ink layer for solid printing and a white ink layer containing aluminum paste for solid printing, which are sequentially stacked. . 2. The light-shielding property according to claim 1, wherein in the white ink layer containing the solid-printed aluminum paste, the amount of aluminum paste in the ink is 10% or less by weight. Shrink film. 3. The transmittance of visible light of 380 to 780 nm is 35% or less, the transmittance of ultraviolet light of 300 to 380 nm is 3% or less, and the whiteness (white hiding degree) is L ^*.
It is 50% or more in value, The light-shielding shrink film according to any one of claims 1 and 2.