JP5620688B2 - Bubble sheet and manufacturing method thereof - Google Patents

Description

  The present invention relates to a bubble sheet having a large number of independent bubbles, and more particularly, to a bubble sheet colored in a predetermined pattern.

  Conventionally, a bubble sheet having a large number of independent air bubbles formed by laminating a back film that encloses air in a protrusion on a cap film formed with a large number of protrusions that bulge in a hollow shape is used for packaging. It is widely used for various applications including cushioning materials.

  Such a bubble sheet, for example, after vacuum forming a protrusion that bulges into a hollow shape by contacting a resin film material in a molten state on the outer peripheral surface of a forming roll provided with a number of suction holes, It can be manufactured by laminating a back film that seals the opening of the formed protrusion (see Patent Document 1, etc.).

JP-A-11-216770

By the way, this type of air bubble sheet may be colored in consideration of its design properties. In such a case, a coloring agent such as a pigment or a dye is usually kneaded into a material resin in an extruder. Will be included.
However, even if the bubble sheet is colored by such a method, only one color can be used. For this reason, the entire bubble sheet can only be uniformly colored with a single color, and there is a limit to improving the design. Furthermore, when changing to a different color, if the replacement of the resin in the extruder is not completed, it is not possible to proceed to the next operation, which takes time for the color change operation and a large amount of resin is wasted. Therefore, there was a disadvantage in terms of cost.

On the other hand, it is also conceivable to color in an arbitrary pattern by printing directly on the surface of the bubble sheet.
However, in such a coloring method, when another article comes into contact with the printed surface and rubs, the color may be transferred to the other article or the print may be peeled off and become thin. I'm worried. For this reason, when printing directly on the surface of the air bubble sheet, it is necessary to select an ink having excellent printability for the material resin used for the air bubble sheet or to perform a process for protecting the printing surface separately. there were.

  This invention is made | formed in view of said situation, and it aims at provision of the bubble sheet which can provide easily the unique design colored by the predetermined pattern, and its manufacturing method.

  The bubble sheet according to the present invention includes a cap film formed with a plurality of protrusions that bulge in a hollow shape, a back film that is laminated on the opening side of the protrusions and encloses air in the protrusions, and a top of the protrusions. A liner film which is laminated on the surface side and covers the protrusions, and a colored adhesive layer containing a hot melt adhesive is formed on each top surface of each protrusion formed on the cap film, the liner film However, it is set as the structure adhere | attached on each top face of each processus | protrusion shape | molded by the said cap film through the said colored adhesive bond layer.

  In addition, the method for producing a bubble sheet according to the present invention provides a cap film in which a molten resin film is supplied to a forming roll provided with a large number of suction holes, and a large number of protrusions that bulge into a hollow shape are vacuum-formed. And forming a base sheet having a large number of independent air bubbles by laminating the cap film by thermal fusion while supplying a back film in which the air is enclosed in the protrusions in a molten state. A colored adhesive layer forming step of forming a colored adhesive layer containing a hot-melt adhesive on each top surface of each protrusion formed on the cap film, and supplying a liner film covering the protrusion in a molten state While adhering to the top surface of each protrusion formed on the cap film through the colored adhesive layer, the front Liner film laminating step for laminating the liner film to the base sheet, there a method comprising the.

  ADVANTAGE OF THE INVENTION According to this invention, the bubble sheet which has the unique design colored by the pattern according to the shape and arrangement | sequence of the processus | protrusion shape | molded by the cap film can be provided.

It is explanatory drawing which shows embodiment of the bubble sheet which concerns on this invention. It is explanatory drawing which shows an example of the base sheet formation process in 1st embodiment of the manufacturing method of the bubble sheet which concerns on this invention. It is explanatory drawing which shows an example of the colored adhesive bond layer formation process in the 1st embodiment of the manufacturing method of the bubble sheet which concerns on this invention, and a liner film lamination process. It is explanatory drawing which shows an example of the colored adhesive bond layer formation process in the 2nd embodiment of the manufacturing method of the bubble sheet which concerns on this invention, and a liner film lamination process. It is explanatory drawing which shows the other example of the colored adhesive bond layer formation process in the 2nd embodiment of the manufacturing method of the bubble sheet which concerns on this invention, and a liner film lamination process.

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

[Bubble sheet]
First, an embodiment of a bubble sheet according to the present invention will be described.
In addition, FIG. 1 is explanatory drawing which shows the bubble sheet which concerns on this embodiment, FIG.1 (a) is a top view which shows the outline of the bubble sheet cut out by the predetermined dimension, FIG.1 (b) is FIG. It is AA sectional drawing of Fig.1 (a).

  In the present embodiment, the bubble sheet 1 includes a cap film 21 in which a large number of protrusions 20 that swell in a hollow shape are formed, and a back film 22 that is laminated on the opening side of the protrusions 20 and encloses air in the protrusions 20. And a liner film 23 which is laminated on the top surface side of the protrusion 20 and covers the protrusion 20.

As the material resin used for each of the films 21, 22, and 23, for example, a polyolefin resin such as a polypropylene resin and a polyethylene resin can be used alone or in admixture of two or more.
Examples of polypropylene resins include propylene homopolymers or copolymers of propylene and other olefins. Other olefins copolymerized with propylene include α-olefins such as ethylene, butene-1, isobutylene and pentene-1, and copolymers with these other olefins include random copolymers, block Any of copolymers may be used.
Examples of the polyethylene resin include high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), linear ultra-low-density polyethylene (LVLDPE), and ethylene-vinyl acetate. A polymer etc. can be illustrated.

In addition, a colored adhesive layer 24 is formed on the top surface of each protrusion 20 formed on the cap film 21.
The colored adhesive layer 24 is formed as a resin layer containing at least a hot melt adhesive, and is colored by adding a colorant such as an arbitrary pigment or dye. As the hot melt adhesive, for example, an adhesive mainly composed of a thermoplastic resin such as an ethylene-vinyl acetate resin, a polyolefin resin, or a polyurethane resin can be used.

  And in this embodiment, the liner film 23 is adhere | attached on each top face of each processus | protrusion 20 shape | molded by the cap film 21 through such a colored adhesive bond layer 24. As shown in FIG.

The air bubble sheet 1 according to the present embodiment configured as described above is formed on the top surface of each protrusion 20 by using at least the material resin described above as the material resin used for the liner film 23 without being transparent and uncolored. The colored adhesive layer 24 thus formed can be observed through the liner film 23. By doing in this way, the bubble sheet 1 which has the unique design colored by the pattern according to the shape and arrangement | sequence of the processus | protrusion 20 can be provided.
Furthermore, the colored adhesive layer 24 is covered with the liner film 23 and does not come into direct contact with other articles. For this reason, unlike the case where the surface is simply printed, the color does not transfer to other articles or the color is not faded by rubbing.

  The colored adhesive layer 24 contains a hot melt adhesive, and the hot melt adhesive is used to adhere to the liner film 23. Therefore, the liner film 23 is securely bonded to the top surfaces of the protrusions 10 formed on the cap film 21 via the colored adhesive layer 24 without the adhesiveness being hindered by the added coloring material. can do.

  Further, if the material resin as described above is used for all of the films 21, 22, and 23 that form the bubble sheet 1 while being transparent and uncolored, the manufacturing process thereof is performed as in the case of adding a colorant to the material resin. In this embodiment, it takes no time to change the color or wastes a large amount of resin. A colorant may be added.

  For example, when the bubble sheet 1 is subjected to a usage mode observed from the liner film 23 side, the cap film 21 or the back film 22 is a material in which both or one of them is colored as necessary. It can consist of resin. The liner film 23 may also be made of a material resin colored within a range that does not hinder the visual recognition of the colored adhesive layer 24. By doing in this way, it becomes possible to diversify expressions in combination with the colored adhesive layer 24 and to further improve the design of the bubble sheet 1.

  In addition, the coloring material added to the colored adhesive layer 24 should be understood in a broad sense, and is not limited to absorbing a specific wavelength in the visible light region and allowing the observer to recognize a specific color. Such as those exhibiting multicolored colors due to the play-off effect, those that emit light by energy emission due to electronic transitions such as phosphorescent pigments and fluorescent pigments, and those that retroreflect incident light such as retroreflective beads Any one or more of these can be selected and used as long as they can give a visual stimulus.

And by using a phosphorescent pigment, a fluorescent pigment, or retroreflective beads as a colorant, the bubble sheet 1 of this embodiment can be used as a reflective material that is generally used as a nighttime safety measure. it can.
When using for such a use, it is preferable to attach the bubble sheet 1 to the arbitrary objects, such as a support | pillar and a guide plate, from the back film 22 side, for example. And it is preferable to make thickness of the cap film 21 or the back film 22 into a thickness (for example, about 10-120 micrometers) which can ensure the rigidity of the bubble sheet 1 so that the attachment operation | work at that time may become easy. Further, the thickness of the liner film 23 should be set to a thickness (for example, 30 μm or less) that does not hinder the visual recognition of phosphorescence emitted from the phosphorescent pigment or the fluorescence emitted from the fluorescent pigment or the retroreflection by the retroreflective beads. preferable.

  In addition, when using the sheet | seat 1 for the use as a general buffer material (bubble buffer sheet), the thickness of each said film 21,22,23 can be about 5-120 micrometers, According to a use. Needless to say, the thickness of each of the films 21, 22, and 23 can be adjusted as appropriate.

[Method for producing bubble sheet (first embodiment)]
Next, 1st embodiment of the manufacturing method of the bubble sheet which concerns on this invention is described. In this embodiment, the bubble sheet 1 as described above is manufactured through a base sheet molding step, a colored adhesive layer laminating step, and a liner film laminating step.

[Base sheet forming process]
FIG. 2 is an explanatory view showing one step of the method for producing a bubble sheet according to the present embodiment, and shows an outline of the base sheet forming step.
In the example shown in FIG. 2, first, a resin film 21 a formed by extruding a material resin from a flat die 31 attached to an extruder (not shown) is placed on the outer peripheral surface of the molding roll 4 provided with a number of suction holes 41. It supplies so that the film 21a may contact in a molten state. Each of the suction holes 41 provided in the molding roll 4 is connected to a vacuum pump (not shown), and by vacuum forming the resin film 21a contacting the outer peripheral surface of the molding roll 4 by reducing the pressure in the suction hole 41, A cap film 21 in which a large number of protrusions 20 bulging in a hollow shape are formed.

  Next, the back film 22 is laminated on the opening side of the protrusion 20 on the cap film 21 on which the protrusion 20 has been formed by vacuum forming while being in close contact with the forming roll 4. The back film 22 is extruded from a flat die 32 attached to an extruder (not shown), supplied in a molten state between the cap film 21 that is in close contact with the forming roll 4 and the pressing roll 5, and the cap film is formed by thermal fusion. 21 is laminated and integrated.

Thereby, the base sheet 2 having a large number of independent bubbles formed by enclosing air in the protrusions 20 is formed. And the base sheet 2 is peeled from the shaping | molding roll 4 with the peeling roll 6, and is sent to a colored adhesive bond layer formation process.
The base sheet 2 formed in the base sheet forming step may be wound on a take-up roll and then used for the colored adhesive layer forming step.

[Colored adhesive layer forming step]
Drawing 3 is an explanatory view showing one process of a manufacturing process of a bubble sheet concerning this embodiment, and shows an outline of a coloring adhesive layer formation process and a liner film lamination process mentioned below.
In the colored adhesive layer forming step, after forming the base sheet 2 as described above, the colored adhesive containing hot melt adhesive is formed on the top surface of each protrusion 20 formed on the cap film 21. The agent layer 24 is formed.

In the present embodiment, in order to form the colored adhesive layer 24 on the top surface of each projection 20 formed on the cap film 21, first, as shown in FIG. The hot melt adhesive holding liquid 80 impregnated in the coating roll 70 is applied to the top surface of each projection 20 using a coating roll 70 that rotates while contacting the top surface of the projection 20 of the base sheet 2 conveyed to the top surface of each projection 20. Apply.
Here, the coating surface of the coating roll 70 is preferably formed using a sponge-like material that is easily impregnated with the hot-melt adhesive-holding liquid 80.

  Next, similarly to the coating roll 70 described above, the hot melt adhesive holding is performed using the spreading roll 71 that rotates while contacting the top surface of the protrusion 20 of the base sheet 2 conveyed along the feed line. A hot-melt adhesive 81 processed into a powder form is selectively sprayed on the top surface of each protrusion 20 coated with the liquid 80. A fine groove 72 is formed by knurling on the surface of the spreading roll 71, and when the powdery hot melt adhesive 81 held in the groove 72 comes into contact with the hot melt adhesive holding liquid 80. Then, it is transferred from the spreading roll 71 and held in the adhesive solution 80, thereby enabling selective spraying to the top surface of each protrusion 20.

  As described above, in this embodiment, the hot melt adhesive 81 is held in the hot melt adhesive holding liquid 80 so that the powdery hot melt adhesive 81 is fixed to the top surface of each protrusion 20. At this time, as the hot-melt adhesive-holding solution 80, at least in the liner film laminating process described later, the powdery hot-melt adhesive 81 is used for each protrusion 20 until the liner film 23 is adhered to the top surface of the protrusion 20. There is no particular limitation as long as it can be fixed on the top surface. For example, it is preferable to use a volatile solution such as alcohol because there is no problem of a residual solution. In addition, a tackifier, rubber resin, or the like can be added to such a volatile solution so that the powdered hot melt adhesive 81 can be easily fixed on the top surface of each protrusion 20.

As described above, the hot melt adhesive 81 processed into a powder form is held in the hot melt adhesive holding liquid 80, thereby forming the colored adhesive layer 24. At this time, the colorant May be added to at least one of the hot melt adhesive holding liquid 80 and the hot melt adhesive 81.
In the example shown in the drawing, the periphery of the spreading roll 71 is surrounded by a casing 73 to prevent the hot melt adhesive 81 processed into a powder form from being scattered around.

[Liner film lamination process]
Next, the material resin is extruded from a flat die 33 attached to an extruder (not shown), and the liner film 23 is formed and supplied so as to be in contact with the top surface of the protrusion 20. At this time, the hot melt adhesive 81 is melted by the residual heat of the liner film, and then solidified to form the colored adhesive layer 24, and the liner film 23 is formed on the protrusion 20 via the colored adhesive layer 24. Adhering to the top surface is ensured and laminated. At this time, it is preferable that the base sheet 2 and the liner film 23 are pressure-bonded from above and below with a pressure-bonding roll (not shown), whereby the adhesion between the two can be made more reliable.

[Method for producing bubble sheet (second embodiment)]
Next, a second embodiment of the method for producing a bubble sheet according to the present invention will be described. In the present embodiment, the base sheet forming step is the same as that of the first embodiment described above, and thus the description of the base sheet forming step is omitted.

[Colored adhesive layer forming step]
In this embodiment, after forming the base sheet 2 in the same manner as in the first embodiment described above, a hot melt adhesive in which a colorant is added to each top surface of each protrusion 20 formed on the cap film 21. The colored adhesive layer 24 is formed by coating 82 in a molten state.

In the present embodiment, the specific means for applying the hot melt adhesive 82 to which the colorant has been added in a molten state is not particularly limited. For example, it can apply using an apparatus as shown in FIG. 4 or FIG.
4 and 5 are both explanatory views showing one step in the method for producing a bubble sheet according to this embodiment, and show an outline of a colored adhesive layer forming step and a liner film laminating step.

  The apparatus shown in FIG. 4 includes a hopper 74 provided with a heating mechanism and a coating roll 75. Then, a coloring material is added to the hot melt adhesive that is put into the hopper 74 and heated and melted, and is supplied to the coating roll 75 while being fed to the top surface of the protrusion 20 of the base film conveyed along the feed line. The hot melt adhesive 82 to which the colorant has been added is applied to the top surface of the protrusion 20 in a molten state by the coating roll 75 that rotates while in contact therewith.

  In the apparatus shown in FIG. 5, a plurality of dropping nozzles 76 are arranged in accordance with the arrangement of the protrusions 20 formed on the cap film 21. Then, in accordance with the feed speed of the base sheet 2 conveyed along the feed line, by dropping the hot melt adhesive 82 in a molten state from the dropping nozzles 76 to the top surfaces of the corresponding projections 20, respectively. A hot melt adhesive 82 to which a colorant is added is applied in a molten state to form the color adhesive layer 24.

  Here, as the hot melt adhesive 82 used in the present embodiment, one that melts at a relatively low temperature is appropriately selected, and when the top surface of the protrusion 20 is applied in a molten state, the protrusion 20 melts and breaks. It is preferable not to mess up. Although not specifically shown, the colored adhesive layer 24 is formed by applying a hot melt adhesive to an appropriate member such as a sheet material, cooling the hot melt adhesive to some extent, and then transferring it to the top surface of the protrusion 20. It is also possible to form

[Liner film lamination process]
Next, as in the first embodiment described above, the material resin is extruded from a flat die 33 attached to an extruder (not shown), and the liner film 23 is formed so as to be in contact with the top surface of the protrusion 20. At this time, even if the hot melt adhesive 82 applied to the top surface of the protrusion 20 is solidified, it is melted again by the residual heat of the liner film, and the liner film 23 is securely adhered as the colored adhesive layer 24 and laminated. can do.
The base sheet 2 and the liner film 23 are preferably pressure-bonded from above and below with a pressure-bonding roll (not shown), as in the first embodiment.

  Although the present invention has been described with reference to the preferred embodiment, it is needless to say that the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. .

  For example, in the above-described embodiment, the resin film 21a that is the cap film 21 formed by vacuum forming the protrusion 20 and the back film 22 that encloses air into the protrusion 20 formed on the cap film 21 are attached to the extruder. Although an example in which the flat dies 31 and 32 are extruded and supplied is shown, the present invention is not limited to this. The resin film 21a and the back film 22 are supplied in a melted state in which the protrusions 20 can be vacuum-formed or heat-sealed while being melted by heating in advance. Also good. The same applies to the liner film 23 laminated on the top surface side of the protrusion 20.

  In the present invention, the bubble sheet 1 may be laminated with a metal foil such as an aluminum foil or a layer made of other materials as needed without departing from the spirit of the present invention.

  The present invention provides a bubble sheet colored with a predetermined pattern.

DESCRIPTION OF SYMBOLS 1 Bubble sheet 2 Base sheet 20 Protrusion 21 Cap film 21a Resin film 22 Back film 23 Liner film 24 Colored adhesive layer 4 Molding roll 41 Suction hole 80 Hot melt adhesive retention liquid 81, 82 Hot melt adhesive

Claims (9)

A cap film formed with a number of protrusions that bulge into a hollow shape;
A back film laminated on the opening side of the protrusion and enclosing air in the protrusion;
A liner film that is laminated on the top surface side of the protrusion and covers the protrusion;
A colored adhesive layer containing a hot melt adhesive is formed only on the top surface of each protrusion formed on the cap film, and the liner film is formed on the cap film via the colored adhesive layer. A bubble sheet characterized by being bonded to the top surface of each of the projections.   The bubble sheet according to claim 1, wherein at least the liner film is made of a transparent uncolored polyolefin resin.   The bubble sheet according to claim 1, wherein at least one of the cap film and the back film is made of a colored polyolefin resin.   The air bubble sheet according to any one of claims 1 to 3, wherein a phosphorescent pigment, a fluorescent pigment, or retroreflective beads are added to the colored adhesive layer. A molten resin film is supplied to a forming roll provided with a large number of suction holes to form a cap film in which a large number of protrusions bulging in a hollow shape are vacuum-formed, and air is enclosed in the protrusions. A base sheet forming step of forming a base sheet having a large number of independent air bubbles by laminating the cap film by thermal fusion while supplying the back film in a molten state;
A colored adhesive layer forming step of forming a colored adhesive layer containing a hot melt adhesive on the top surface of each protrusion formed on the cap film,
While supplying the liner film covering the protrusions in a molten state, the liner film is adhered to the top surface of each protrusion formed on the cap film via the colored adhesive layer. Liner film laminating process for laminating,
A method for producing an air bubble sheet, comprising:   The method for producing a bubble sheet according to claim 5, wherein a transparent uncolored polyolefin-based resin is used as a material resin used for the cap film, the back film, and the liner film.   The hot melt adhesive holding liquid is applied to the top surface of each protrusion formed on the cap film, and then the hot melt adhesive processed into a powder form is held in the hot melt adhesive holding liquid. The method for producing a bubble sheet according to claim 5 or 6, wherein a colored adhesive layer is formed.   The manufacturing method of the bubble sheet of Claim 7 which adds a coloring material to at least one among the said hot-melt-adhesive holding | maintenance liquid and the said powdery hot-melt-adhesive.   The colored adhesive layer is formed on the top surface of each protrusion formed on the cap film by applying a hot-melt adhesive added with a coloring material in a molten state. A method for producing a bubble sheet.

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