JP2011063286A - Packaging bag with window and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a packaging bag with a window having a sufficient strength in which viewing windows of various kinds of designs can be formed, and a method for easily manufacturing the packaging bag with the window. <P>SOLUTION: In the packaging bag 1 with the window, a base paper 2 is formed in a shape of a bottomed bag, and a transparent window 4 is formed in a part of the base paper 2. The base paper 2 is a machine-grazed craft paper having a basic weight of 50-110 g/m<SP>2</SP>. The transparent window 4 is formed by impregnating a transparency agent in the base paper 2. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a packaging bag with a window having a see-through window and a manufacturing method thereof.

  Paper packaging bags are widely used in various applications such as merchandise sales and storage. In such a paper packaging bag, a packaging bag with a window in which a transparent window is formed in a part of the packaging bag for the purpose of visually recognizing the contents from the outside is known. For example, a packaging bag with a window is proposed in which a part of a paper packaging bag is punched to form a window hole, and a transparent film is bonded to form a transparent window so as to close the window hole (for example, (See Patent Document 1 or 2).

JP 11-059694 A Utility Model Registration No. 3092329

  As for the packaging bag with a window of patent document 1 or 2, the contents can be visually recognized through a transparent film from a window hole part. However, since a part of the bag is punched to form the window hole, there is a problem that the strength of the packaging bag is inevitably lowered.

  Specifically, the strength of the packaging bag is locally reduced by forming a weak portion called a window hole, and the packaging bag may be broken starting from the window hole due to the weight of the contents. Moreover, since the transparent film bonded together to a window hole is normally bonded from the inner side of a bag, when a content is put, there is also a possibility that a transparent film may peel.

  In particular, it is not a packaging bag for the purpose of packaging a relatively light content such as food like the packaging bag with a window described in Patent Document 1 or 2, but a heavy or box-shaped package is used as the content. In the case where the same configuration is applied to a square bottom bag such as a handbag, which is often the case, the above-described problem is further concerned.

  Moreover, the packaging bag with a window of patent document 1 or 2 says that it is difficult to form a large-area perspective window or a complex-shaped perspective window with respect to the surface area of the packaging bag due to the above-described problem in strength. There was a problem. In addition, because the window hole is blocked with a transparent film, 1) two types of materials with different printing properties, paper and transparent film, are used, and 2) a step is formed at the boundary between the paper and the transparent film. As a result, there has been a problem that it is technically difficult to print on the transparent film portion forming the transparent window. Therefore, when trying to manufacture a packaging bag rich in design, there has been a problem that the manufacturing process becomes complicated and efficient production is difficult.

  Furthermore, the packaging bag with a window described in Patent Document 1 or 2 requires both steps of punching a window hole by punching and bonding a transparent film to the window hole, and is easy to manufacture. I couldn't say that.

  The present invention has been made in view of the above-described problems of the prior art, and includes a packaging bag with a window having sufficient strength and capable of forming a transparent window with various designs, and the packaging bag with a window. Provided is a production method that can be easily produced.

  As a result of diligent investigations to solve the problems of the prior art as described above, the present inventor 1) uses a single glossy kraft paper having a predetermined basis weight as a base paper of a packaging bag, and 2) the single gloss bleaching. The inventors have conceived that the above problems can be solved by impregnating a kraft paper with a clearing agent to form a transparent window, and have completed the present invention. Specifically, the present invention provides the following packaging bag with a window and a manufacturing method thereof.

[1] A single-sided bleached craft in which a base paper is formed into a bottomed bag shape and a transparent window is formed on a part of the base paper, the base paper having a basis weight of 50 to 110 g / m ² A packaging bag with a window, wherein the see-through window is formed by impregnating the base paper with a clearing agent.

[2] The window according to [1], wherein the transparent window is formed by impregnating the base paper with a UV curable transparent agent containing a (meth) acrylate monomer and a photopolymerization initiator. Packing bag with.

[3] The windowed packaging bag according to [1], wherein the transparent window is formed by impregnating the base paper with a rosin-based aqueous clarifier.

[4] The windowed packaging bag according to any one of [1] to [3], wherein a colored portion is formed in a window frame of the see-through window.

[5] A colored portion is formed on the surface of the base paper, the clearing agent is impregnated from the back surface of the base paper, and the colored portion and the impregnating portion of the clearing agent are formed in a superimposed manner. The windowed packaging bag according to any one of [1] to [4].

[6] The windowed packaging bag according to any one of [1] to [5], wherein the see-through window is formed in a geometric shape, and the see-through pattern of the geometric shape is formed.

[7] The windowed packaging bag according to any one of the above [1] to [6], which is a square bottom bag having a ridge and formed into a bottomed square tube shape.

[8] The windowed packaging bag according to [7], further including a handle for carrying.

[9] A method for producing a packaging bag with a window, wherein a transparent agent is applied to a part of a base paper, the transparent paper is impregnated with the transparent agent to form a transparent window, and the base paper is bag-made. As the base paper, single gloss bleached kraft paper with a basis weight of 50 to 110 g / m ² is used, and as the clearing agent, a clearing agent whose viscosity is adjusted to 200 to 2000 cps (35 ° C.) is used, and a plurality of cuts are on the surface. Using at least one flexographic printing plate selected from the group consisting of a flexographic resin plate and a flexographic sponge plate formed on the substrate, using the flexographic printing plate impregnated with the clearing agent, and making the transparency with respect to the base paper The manufacturing method of the packaging bag with a window which apply | coats the said transparentizing agent to a part of said base paper by carrying out flexographic printing of the agent.

[10] The method for manufacturing a packaging bag with a window according to [9], wherein a flexographic resin plate having a plurality of cuts formed on a surface thereof is used as the flexographic printing plate.

[11] A UV curable clearing agent having a viscosity adjusted to 200 to 400 cps (35 ° C.) and containing a (meth) acrylate monomer and a photopolymerization initiator is used as the clearing agent. [9] or [10] wherein the UV curable clearing agent is applied to a part of the base paper, the base paper is impregnated with the transparentizing agent, and then irradiated with ultraviolet rays to cure the UV curable clearing agent. ] The manufacturing method of the packaging bag with a window of description.

[12] As the clearing agent, a rosin-based aqueous clearing agent having a viscosity adjusted to 1000 to 2000 cps (35 ° C.) is used, and the rosin-based aqueous clearing agent is applied to a part of the base paper, The method for producing a packaging bag with a window according to [9] or [10], wherein base paper is impregnated with the clearing agent and then heated to cure the rosin-based aqueous clearing agent.

[13] After applying the clearing agent to a part of the base paper and impregnating the base paper with the clearing agent, the base paper impregnated with the clearing agent is dried, and again, The manufacturing method of the packaging bag with a window in any one of said [9]-[12] which apply | coats the said transparentizing agent to a part and makes the said base paper impregnate the said transparentizing agent.

[14] The colored portion is formed by performing color printing on the surface of the base paper, and then the transparentizing agent is applied to the back surface of the base paper so as to overlap the colored portion. ] The manufacturing method of the packaging bag with a window in any one of.

  The packaging bag with a window of the present invention has a sufficient strength and can form a transparent window with various designs. Moreover, the manufacturing method of this invention can manufacture the said packaging bag with a window simply by the method similar to printing.

It is a schematic perspective view which shows typically the state which looked at the packaging bag with a window of this invention from the front side. It is a schematic perspective view which shows typically the state which looked at the packaging bag with a window shown in FIG. 1 from the back side.

  Hereinafter, the form of carrying out the packaging bag with a window of this invention, its manufacturing method, and the square bottom bag with a window, the square bottom bag provided with the handle for handbags (henceforth "handbag"), and its manufacture. A specific example will be described with reference to a method example. However, this invention broadly includes the packaging bag with a window provided with the invention specific matter, and its manufacturing method, and is not limited to the following embodiment.

[1] Packaging bag with window:
The packaging bag with a window of the present invention is a packaging bag with a window 1 in which a base paper 2 is formed in a bottomed bag shape and a transparent window 4 is formed in a part of the base paper 2 as shown in FIGS. 1 and 2. .

[1-1] Base paper:
In the packaging bag with a window of the present invention, single gloss bleached kraft paper is used as a base paper. “One-sided bleached kraft paper” is a kraft paper made from bleached kraft pulp and made glossy on one side by making paper with a Yankee machine. Specific examples include “Blizzard (trade name)” manufactured by Oji Paper Co., “Blea Ryuo (trade name)” manufactured by Daio Paper Co., Ltd., “Capital Wrap (trade name)” manufactured by Nippon Paper Industries Co., Ltd. it can. Among them, it is preferable to use “Blizzard (trade name)” manufactured by Oji Paper Co., Ltd.

The packaging bag with a window of the present invention uses a single glossy kraft paper having a basis weight in the range of 50 to 110 g / m ² . By setting the basis weight to be 50 g / m ² or more, it is possible to obtain a packaging bag with a window having sufficient strength while improving printing processability. In addition, by setting the basis weight to 110 g / m ² or less, the light transmission of the see-through window becomes sufficient, and the inside can be easily visually recognized, which is flexible and can be manufactured at low cost. In order to obtain these effects more reliably, the basis weight is preferably in the range of 60 to 100 g / m ² , and more preferably in the range of 70 to 90 g / m ² .

[1-2] Transparent window:
The “transparent window” means a portion of the base paper that has lower opacity than other portions and can visually recognize the contents. As shown in FIG. 1, in the front part 6 of the packaging bag 1 with a window, the inside area | region of the flower-shaped outline surrounding the coloring part 8 (8a) of the logo which consists of four alphabets is the transparent window 4 (4a), coloring An inner region of the portion 8a is a see-through window 4 (4b). Further, the inner region of the colored portion 8 (8b) having the leaf-shaped contour is also a see-through window 4 (4c). On the other hand, as shown in FIG. 2, in the back surface part 10 of the packaging bag 1 with a window, the part of the logo which consists of four alphabets is the see-through window 4 (4d). The inner area of the flower-shaped contour surrounding the fluoroscopic window 4c is the colored portion 8 (8c), and the inner area of the fluoroscopic window 4d is the colored portion 8 (8d).

  The opacity of the see-through window is preferably 50% or less, more preferably 45% or less, and particularly preferably 30% or less. "Opacity" as used in this specification means the opacity measured by the method based on JIS P8148 (ISO2470). As the measuring device, for example, “Reflectometer TC-6D (trade name)” manufactured by Tokyo Denshoku Co., Ltd. can be used.

  The see-through window needs not only to have low opacity, but also to have opacity lower than that of the base paper other than the see-through window (that is, the base paper itself). In the present invention, the difference between the opacity of the base paper itself and the opacity of the transparent window is preferably 40% or more, and more preferably 50% or more.

  The see-through window is formed by impregnating a base paper with a clearing agent. As the clearing agent, for example, a UV curable clearing agent, a rosin aqueous clearing agent, or the like can be suitably used.

  “UV curable clearing agent (sometimes referred to as“ UV varnish ”)” is a composition containing a (meth) acrylate monomer and a photopolymerization initiator. The UV curable clearing agent has the effect of reducing the opacity of the base paper by impregnating the base paper. In addition, when irradiated with ultraviolet rays, the photopolymerization initiator is decomposed, and the (meth) acrylate monomer is polymerized to cure the impregnated portion. Therefore, sufficient strength can be maintained even when the transparent window is formed, and the strength of the transparent window portion can be improved by the cured resin.

  As the UV curable clearing agent, for example, “Cybinol X-507-251V (trade name)” manufactured by Seiden Chemical Co., Ltd. can be suitably used.

  The “rosin-based aqueous clarifying agent” is a composition containing an emulsion of rosin resin such as natural rosin resin and water. The rosin-based aqueous clarifying agent has the effect of reducing the opacity of the base paper by impregnating the base paper. Moreover, the composition in which the thermosetting resin is mixed also has an action of curing the impregnated part by heating. Therefore, sufficient strength can be maintained even when the transparent window is formed, and when the thermosetting resin is mixed, the strength of the transparent window portion can be improved by the cured resin. Furthermore, since the composition is water-based, it is preferable in that the base paper can be easily recycled.

  As the rosin-based aqueous clarifying agent, for example, “Unit No. 10N Winter (trade name)”, “Eco Ross Isei AC-130N (trade name)” manufactured by Nikko Chemical Co., Ltd. can be preferably used. .

  When a thermosetting resin is mixed with the rosin-based aqueous clarifying agent, a mixture of a modified epoxy resin and a solvent can be used as a modifier. More specifically, in each case, “Modifier M-14 (trade name)”, “Modifier HS (trade name)” manufactured by Nikko Chemical Co., Ltd. can be preferably used. Further, in order to adjust the viscosity, a rosin-based aqueous clarifying agent added with a diluent solvent may be used. Although the kind of dilution solvent is not specifically limited, A solvent with high affinity with water, for example, propylene glycol monomethyl ether etc. can be used conveniently.

  The shape and size of the see-through window are not particularly limited. In the present invention, since the transparent window is formed by impregnating the base paper with the clearing agent, the transparent window having various shapes can be formed by the same method as the printing. Therefore, it is possible to form see-through windows with various designs, and the design is excellent.

  Among them, it is preferable that the transparent window 4 is formed in a geometric shape and a transparent pattern of the geometric shape is formed like the transparent windows 4a and 4c shown in FIG. 1 or the transparent window 4d shown in FIG. “Geometric shape” means a shape combining triangles, squares, rhombuses, other polygons, circles, ellipses, and the like, and does not include simple triangles, squares, rhombuses, polygons, circles, and the like. A wrapping paper (and thus a square bottom bag or the like) on which a geometric perspective pattern is formed has high design value because of its excellent design.

  In addition, since the method of forming a transparent window by impregnating a base paper with a clearing agent does not reduce the strength of the base paper, unlike the packaging bag with a window described in Patent Document 1 or 2, the transparent window having a large area is used. It is also possible to form

  In the packaging bag with a window of this invention, it is preferable that the coloring part is formed in the window frame of a see-through window. By combining the design of the see-through window (that is, the translucent portion) and the design of the colored portion, it is possible to form more various designs.

  As shown in FIG. 1, the packaging bag 1 with a window shown in FIGS. 1 and 2 has a logo coloring portion 8 a made up of four letters in the window frame of the flower-shaped see-through window 4 a at the front portion 6. Has been. As shown in FIG. 2, in the back surface portion 10, a circular colored portion 8 d is formed in the window frame of the logo see-through window 4 d composed of four alphabetic characters.

  Among them, a colored portion is formed on the surface of the base paper, the transparent agent is impregnated from the back surface of the base paper, and the colored portion and the impregnated portion of the clearing agent are formed in a superimposed manner. Is preferred. Unlike the packaging bag with a window described in Patent Document 1 or 2, the packaging paper having such a structure can easily form a colored portion in the transparent window portion.

  Such a wrapping paper can form a colored portion on the surface of the base paper by normal printing, and on the other hand, a transparent window can be formed on the back surface of the base paper by printing a transparentizing agent. Therefore, steps such as punching a window hole by punching and bonding a transparent film to the window hole as in the packaging bag with a window described in Patent Document 1 or 2 are unnecessary, and manufacturing is relatively easy.

  As shown in FIG. 1, the packaging bag 1 with a window shown in FIGS. 1 and 2 has a flower-shaped see-through window 4 a and a logo coloring portion 8 a made up of four alphabet letters superimposed on the front portion 6. Has been. In addition, as shown in FIG. 2, on the back surface portion 10, a logo see-through window 4 d made up of four alphabet letters and a circular colored portion 8 d are formed in a superimposed manner. This packaging bag 1 with a window has a colored portion 8 formed on the surface of a base paper 2 by normal printing, and a transparent window 4 is formed on the back surface of the base paper 2 by printing a clearing agent.

[2] Packaging bag:
The packaging bag of this invention can be obtained by forming the base paper in which the transparent window was formed by the conventionally well-known bag making process in the shape of a bottomed bag. The packaging bag of the present invention may be a so-called envelope-type packaging bag, but is preferably a square-bottom bag having a ridge and formed into a bottomed rectangular tube shape (a square-bottom bag with a window). For example, a paper cylinder having openings at both ends is formed from a base paper on which a transparent window is formed, and the ends on the one opening side of the paper cylinder are folded and joined to each other to form a bottom portion and a ridge. Thereby, the square bottom bag formed in the bottomed square cylinder shape can be obtained.

  1 and 2 has a front part 6, a rear part 10, a collar part 12, and a bottom part 14, and an end part facing the bottom part 14 is an opening part 16 (with a window). Square bottom bag 50). Therefore, when the folded collar portion 12 is unfolded, a square tube bag having a rectangular bottom portion 14 is obtained.

  It is preferable that the packaging bag with a window of this invention is further provided with the handle 18 for a handbag like the square bottom bag 50 with a window shown in FIG.1 and FIG.2. That is, it is preferable to use a handbag with a handle. The packaging bag with a window of the present invention is preferable in that it has a fluoroscopic window and is excellent in design, and has sufficient strength as a handbag that often contains heavy items as contents.

  The handle can be attached to the square-bottom bag by a conventionally known manual process. For example, two holes are drilled along the edge of the opening in each of the front and back portions of the square bottom bag. Next, a string, a resin belt, or the like serving as a handle is passed through each of the holes in the front and back portions. Finally, the handle can be attached to the square bag by making a knot or the like so that the handle does not come out of the hole.

  The square bottom bag 50 with a window shown in FIGS. 1 and 2 has two circular holes formed along the edge of the opening 16 in each of the front part 6 and the rear part 10, and the front part 6 and the rear part 10. A spindle string is passed through each of the circular holes of the portion 10, and a handle 18 is attached by making a knot inside the bag.

[3] Manufacturing method of packaging bag with window:
The method for manufacturing a packaging bag with a window according to the present invention includes a window packaging bag for forming a transparent window by applying a clearing agent to a part of a base paper, impregnating the base paper with a clearing agent, and forming the base paper. It is a manufacturing method.

[3-1] Base paper:
As the base paper, the glossy kraft paper having a basis weight of 50 to 110 g / m ² already described is used. The same applies to a more preferable basis weight range.

[3-2] Clarifying agent:
As the clearing agent, a clearing agent having a viscosity adjusted to 200 to 2000 cps (35 ° C.) is used. By setting the viscosity to 200 cps or more, it is possible to obtain the effect that bleeding at the time of printing is reduced. By setting the viscosity to 2000 cps or less, it becomes easy to apply and impregnate the clearing agent.

  The “viscosity” referred to in the present invention uses a B-type viscometer (specifically, a BM viscometer for general measurement) in accordance with JIS K7117-1 for the UV curable clarifying agent described above. It means the viscosity measured. At this time, as the rotor, the rotor No. 2 is measured under conditions of a temperature of 35 ° C. and a rotation speed of 30 rpm. On the other hand, for the rosin-based aqueous clarifying agent described above, rotor No. Except that 3 is used, the measurement is performed under the same conditions as for the UV curable clearing agent.

  When using the above-described UV curable clearing agent as the clearing agent, the viscosity is preferably adjusted to 200 to 400 cps (35 ° C.), more preferably 250 to 350 cps. When the rosin-based aqueous clarifying agent described above is used as the clarifying agent, the viscosity is preferably adjusted to 1000 to 2000 cps (35 ° C.), and more preferably adjusted to 1300 to 1700 cps (35 ° C.). It is particularly preferable to adjust to 1400 to 1600 cps. The viscosity of the clarifying agent can be appropriately adjusted by a conventionally known method such as heating or addition of a diluting solvent.

[3-3] Application means:
As a means for applying the clarifying agent, at least one flexographic printing plate selected from the group consisting of a flexographic resin plate and a flexo sponge plate having a plurality of cuts formed on the surface thereof is used. By using these coating means, the resin plate can be sufficiently cut into the notches of the resin plate and the pores of the sponge plate, and the clearing agent can be uniformly applied to the base paper. It becomes.

  Generally, “flexographic printing” is rotary letterpress printing in which a flexographic printing plate having convex portions corresponding to a printing shape formed on the surface thereof is used to transfer liquid ink adhered to the convex portions to a base paper. The “flexographic printing plate” means a printing plate for flexographic printing (letter plate) made of a flexible elastic material such as rubber and photosensitive resin.

  The “flexo resin plate” means that the plate material constituting the printing plate of the flexographic printing plate does not have pores.

  Although it does not specifically limit about hardness, In order to ensure a softness | flexibility and durability, it is preferable that hardness is 40-80 degree | times, and it is still more preferable that it is 50-70 degree | times. Hardness means the hardness measured by the method based on JISK6253. As the measuring device, a durometer, for example, “Asker Rubber Hardness Tester A type (trade name)” manufactured by Kobunshi Keiki Co., Ltd. can be used. Examples of the plate material having such hardness include “Syrel (trade name)” manufactured by DuPont (hardness 57 degrees).

  In the production method of the present invention, when a flexographic resin plate is used as a coating means, it is necessary to form a plurality of cuts on the surface in order to sufficiently contain a clarifying agent.

  The mode of cutting is not particularly limited. For example, the aspect etc. which arrange | position a linear notch in parallel and at equal intervals can be mentioned. In this case, the notch interval is preferably 10-14 lines / cm width, and preferably 11-13 lines / cm width.

  The depth of the cut is not particularly limited, but it is preferable to make a cut with a depth of 30 to 60% with respect to the total thickness of the flexographic resin plate, and it is preferable to make a cut with a depth of 40 to 50%. By setting it to 30% or more, it becomes possible to sufficiently include a clarifying agent. On the other hand, the strength reduction of the flexographic resin plate due to the cutting can be suppressed by setting it to 60% or less.

  The “flexo sponge plate” means a sponge-like plate having pores in the plate material constituting the printing plate among the flexographic printing plates.

  The flexo sponge plate is a sponge-like porous body having a large number of pores inside. Therefore, it is preferable in that it has higher flexibility than the above-described flexographic resin plate and can contain a large amount of a clarifying agent. Examples of the plate material of the flexo sponge plate include “Sekisui Vinyl Foam CB-70 Ash (trade name)” manufactured by Sekisui Chemical Co., Ltd. “Sekisui Vinyl Foam CB-70 Ash (trade name)” manufactured by Sekisui Chemical Co., Ltd. is preferable in that it has a low density, high flexibility, and can absorb a large amount of a clarifying agent.

  In the production method of the present invention, when a flexographic sponge plate is used as the coating means, it is preferable to make the thickness larger than that of a normal flexographic printing plate in order to sufficiently contain a clarifying agent. Although it does not specifically limit about specific thickness, It is preferable to set it as 1.5 to 2 times the thickness of a normal flexographic printing plate.

[3-4] Application / impregnation method:
The production method of the present invention is to apply the clearing agent to a part of the base paper by flexographic printing of the clearing agent on the base paper using the above-described flexographic printing plate impregnated with the clearing agent. is there. That is, for matters other than the types of the base paper, the clearing agent and the flexographic printing plate, the clearing agent is applied according to the conventional flexographic printing.

  The printing speed is not particularly limited, but is preferably 10 to 30 m / min, and more preferably 15 to 25 m / min. Productivity can be improved by setting it as 10 m / min or more. It becomes possible to apply | coat a clearing agent uniformly by setting it as 30 m / min or less.

  The base paper coated with the clearing agent is heated for the purpose of drying. For example, heating methods, such as hot air injection and infrared irradiation, can be mentioned. The heating temperature and the heating time are not particularly limited as long as drying is possible. Therefore, it may be set as appropriate according to the type of the clarifying agent.

  For example, when a UV curable clearing agent is used as the clearing agent, the temperature of the base paper is preferably 50 to 90 ° C. and heated for 20 to 60 seconds, the temperature of the base paper is set to 60 to 80 ° C. and 30 seconds. More preferably, heating is performed for ˜50 seconds.

  When using a UV curable clearing agent, it is preferable to irradiate with ultraviolet rays after the heating. Thereby, UV hardening type transparentizing agent can be hardened.

  When using a rosin-based aqueous clarifying agent, the temperature of the base paper is preferably 120 to 150 ° C. and is preferably heated for 40 to 80 seconds, and the temperature of the base paper is set to 130 to 140 ° C. and heated for 50 to 70 seconds. Is more preferable. The rosin-based aqueous clearing agent is heated at a higher temperature than the UV curable clearing agent in order to sufficiently volatilize the solvent water and to sufficiently cure the thermosetting resin that may be added as an additive. It is preferable to do.

  In the production method of the present invention, a clearing agent is applied to a part of the base paper, the base paper is impregnated with the clearing agent, and then the clearing agent is applied again to a part of the base paper, and the transparent paper It is also preferable to impregnate the agent. That is, it is preferable to apply the clearing agent a plurality of times in a superimposed manner. As a result, the opacity of the see-through window can be further reduced. It is also preferable that after the first application of the clarifying agent, the clearing agent is sufficiently dried and then the second application of the clarifying agent is performed. By doing so, the clearing agent applied the second time is sufficiently impregnated, and the opacity of the viewing window can be further reduced.

  In addition, in the above-described multiple application of the clearing agent, the second clearing agent application may be performed on the same side of the base paper as the first clearing agent application (single-sided printing) or different. It may be performed on the side surface (double-sided printing).

[3-5] Color printing:
In the production method of the present invention, in addition to the printing of the clarifying agent, it is also one of preferred embodiments to perform ordinary colored printing. Specifically, it is preferable to form a colored portion by performing color printing on the surface of the base paper, and then apply a clearing agent on the back surface of the base paper so as to overlap the colored portion.

  The colored printing can be performed by a conventionally known printing method such as flexographic printing, gravure printing, offset printing, and the like.

  Hereinafter, the present invention will be described in more detail with reference to an example of manufacturing a square bottom bag with a window. However, the present invention broadly encompasses a packaging bag with a window having the invention-specific matters and a method for manufacturing the same, and is not limited to the following examples.

[1] Example 1:
As a packaging bag with a window of Example 1, a packaging bag with a window 1 in which a transparent window 4 was formed on a part of a base paper 2 as shown in FIGS. 1 and 2 was manufactured.

As the base paper 2, “Blizzard (trade name)” manufactured by Oji Paper Co., Ltd. was used. A basis weight of 80 g / m ² and an opacity of 80.2% were used. The surface of the base paper was colored in advance to form a colored portion.

  Next, a clearing agent was applied to the back surface of the base paper so as to overlap the colored portion. Specifically, a transparent agent was applied to part of the base paper, and the transparent paper was impregnated with the base paper to form a transparent window. As a result, a colored portion was formed on the surface of the base paper, and a transparent agent was impregnated from the back surface of the base paper, thereby obtaining a base paper in which the colored portion and the impregnated portion of the clearing agent were formed in a superimposed manner.

  As the clearing agent, a UV curable clearing agent having a viscosity adjusted to 310 cps (35 ° C.) was used. As the UV curable clearing agent, “Cybinol X-507-251V (trade name)” manufactured by Seiden Chemical Co., Ltd. was used. The viscosity was adjusted by heating the clarifying agent to 35 ° C.

  As a means for applying the clearing agent, a flexographic resin plate having a plurality of cuts formed on the surface thereof was used. As a plate material for the flexographic resin plate, “Syrel (trade name)” manufactured by DuPont was used. The thickness was 2.84 mm.

  Protrusions that match the printing shape of the clearing agent were formed on the plate material, and a plurality of cuts were formed on the surfaces of the convexes. Specifically, straight cuts were formed in parallel and at equal intervals at a rate of 11.8 lines / cm width (30 lines / 1 inch width). The depth of the cut was 1.1 to 1.3 mm. That is, a cut with a depth of 38.7 to 45.8% of the thickness of the flexographic resin plate was formed.

  The clearing agent was included in the flexographic resin plate, and the clearing agent was flexographically printed on the base paper, thereby applying the clearing agent to a part of the back surface of the base paper. The printing speed was 20 m / min. Two seconds after the coating was completed, hot air jetting and infrared irradiation were performed, the temperature of the base paper was set to 70 ° C., and the coating was heated for 40 seconds. Thereafter, ultraviolet rays were irradiated to cure the UV curable clearing agent. The opacity of the formed see-through window was 30.0%. That is, the opacity decreased by 50.2% with respect to the base paper. The results are shown in Table 1.

  In addition, about the said base paper, the paper cylinder which has a both-ends opening part was formed, the edge part by the side of one opening part of the said paper cylinder was folded, and it mutually joined, and formed the bottom part and the ridge. Thereby, as shown in FIG.1 and FIG.2, the bottomed square tube-shaped packaging bag 1 with a window (the square bottom bag 50 with a window) which had the collar part 12 was obtained. This square-bottomed bag with a window has a bottomed rectangular tube shape with a height of 257 mm, a width of 218 mm, and a depth of 119 mm. In addition, the 40 mm from the opening end made a double structure by folding the base paper.

  Next, a handle was attached to the square bottom bag with a window by a conventionally known manual processing. As shown in FIGS. 1 and 2, two circular holes were formed in the front portion 6 and the back portion 10 at intervals of 80 mm at positions 23 mm below the edge of the opening 16. The diameter of the circular hole was 5 mm. A spindle string having a length of 240 mm was passed through each of the circular holes in the front part 6 and the rear part 10, and a handle 18 was attached by making a knot inside the bag. Thereby, the square bottom bag 50 with a window (namely, handbag of a square bottom) shown in FIG.1 and FIG.2 was obtained.

[2] Example 2, Comparative Examples 1-6:
A packaging bag with a window (a square bottom bag with a window) was manufactured in the same manner as in Example 1 except that the type of the base paper was changed to the base paper shown in Table 1. As the base paper, those manufactured by Oji Paper Co., Ltd. were used. Specifically, “Blizzard (trade name)” is used as the single gloss bleached kraft paper of Example 2 and Comparative Example 1, and “RC single gloss (trade name)” is used as the waste paper-mixed single gloss kraft paper of Comparative Example 2. "Whale (trade name)" as the bi-bleached kraft paper of Comparative Example 3, "Semi-bleached OK Gold (trade name)" as the semi-bleached kraft paper of Comparative Example 4, and Semi-bleach of Comparative Example 5 As craft paper, “semi-bleached OK gold (product name)” is used, as unbleached kraft paper of Comparative Example 5, “unbleached OK gold (product name)”, and as coated paper of Comparative Example 6, “OK blankage ( Product name) ”was used. The results are shown in Table 1.

As shown in Table 1, the packaging bags with windows of Examples 1 and 2 using glazed bleached kraft paper having a basis weight of 50 to 110 g / m ² as the base paper have an opacity of 50% or less and the opacity of the base paper itself. The difference in opacity between the transparent window and the transparent window was 40% or more, indicating a good result. In particular, the packaging bag with window of Example 1 showed particularly good results with an opacity of 30% or less and a difference between the opacity of the base paper itself and the transparency of the fluoroscopic window was 50% or more.

  On the other hand, the windowed packaging bags of Comparative Example 1 and Comparative Examples 4 to 6 have an opaqueness of the viewing window of more than 50%, and the difference between the opacity of the base paper itself and the transparency of the viewing window is less than 40%. Met.

  The windowed packaging bags of Comparative Examples 2 and 3 had an opacity of 50% or less, and the difference between the opacity of the base paper itself and the opacity of the fluoroscopic window was 40% or more, and these points showed good results. However, the appearance of the see-through window was poor. Specifically, since the packaging bag with a window of Comparative Example 2 used unpolished kraft paper mixed with waste paper as a base paper, there was a problem that a large number of bundled fibers appeared in the fluoroscopic window and the opacity was uneven. . In addition, the packaging bag with a window of Comparative Example 3 used bleached kraft paper with both sides as the base paper, so that the clearing agent exudes to the surface of the fluoroscopic window, and the opacity was uneven. . Moreover, since the outer periphery of the see-through window is not a glossy surface, the visibility of the see-through window is lowered.

[3] Example 3:
A windowed packaging bag of Example 3 was produced in the same manner as in Example 1 except that the type of application means was changed to a flexo sponge plate.

  “Sekisui Vinyl Foam CB-70 Ash (trade name)” manufactured by Sekisui Chemical Co., Ltd. was used as the plate material for the flexo sponge plate. Usually, the thickness of the flexo sponge plate is 3 mm, but in Example 3, it is 5 mm. That is, the thickness was 1.7 times the normal thickness. Protrusions that match the printed shape were formed by die cutting using a corroded blade. The results are shown in Table 2.

[4] Example 4:
A windowed packaging bag of Example 4 was produced in the same manner as Example 1 except that the coating method was changed. Specifically, the clearing agent was applied twice in a superimposed manner.

  First, by the same method as in Example 1, the clearing agent is included in the flexographic resin plate, and the clearing agent is flexographically printed on the base paper to apply the clearing agent to a part of the back surface of the base paper. did. The printing speed was 15 m / min. This process was repeated twice. Two seconds after the coating was completed, hot air jetting and infrared irradiation were performed, the temperature of the base paper was set to 70 ° C., and the coating was heated for 40 seconds. Thereafter, ultraviolet rays were irradiated to cure the UV curable clearing agent. The results are shown in Table 2.

  As shown in Table 2, the windowed packaging bag of Example 3 using the flexo sponge plate has an opacity of less than 30%, and the difference between the opacity of the base paper itself and the transparency of the fluoroscopic window is more than 50%. Compared with the windowed packaging bag of Example 1, better results were shown.

  Further, the windowed packaging bag of Example 4 in which the coating method was changed also had an opacity of less than 30%, and the difference between the opacity of the base paper itself and the opacity of the fluoroscopic window exceeded 50%. Even better results were obtained as compared with the other packaging bags with windows.

  The packaging bag with a window of the present invention can be used as a square-bottom bag such as a handbag that often contains heavy items or box-like packages. The manufacturing method of the packaging bag with a window of this invention can be used suitably in order to manufacture the packaging bag with a window of this invention.

1: packaging bag with window, 2: base paper, 4, 4a, 4b, 4c, 4d: see-through window, 6: front part, 8, 8a, 8b, 8c, 8d: colored part, 10: back part, 12: bag Part, 14: bottom part, 16: opening part, 18: handle, 50: square bottom bag with a window.

Claims (14)

A base paper is formed into a bottomed bag shape, and a packaging bag with a window in which a transparent window is formed in a part of the base paper,
The base paper is a single gloss bleached kraft paper having a basis weight of 50 to 110 g / m ² ,
The transparent window is a packaging bag with a window formed by impregnating the base paper with a clearing agent.   2. The packaging bag with a window according to claim 1, wherein the transparent window is formed by impregnating the base paper with a UV curable clearing agent containing a (meth) acrylate monomer and a photopolymerization initiator.   The packaging bag with a window according to claim 1, wherein the see-through window is formed by impregnating the base paper with a rosin-based aqueous clarifying agent.   The packaging bag with a window as described in any one of Claims 1-3 in which the coloring part is formed in the window frame of the said see-through window.   2. A colored portion is formed on the surface of the base paper, the clearing agent is impregnated from the back surface of the base paper, and the colored portion and the impregnating portion of the clearing agent are formed in a superimposed manner. The packaging bag with a window as described in any one of -4.   The packaging bag with a window as described in any one of Claims 1-5 in which the said see-through window is formed in geometric shape, and the see-through pattern of the said geometric shape is formed.   The packaging bag with a window as described in any one of Claims 1-6 which is a square bottom bag which has a bag and was formed in the bottomed square cylinder shape.   The packaging bag with a window of Claim 7 further provided with the handle for handbags. A method of manufacturing a packaging bag with a window, wherein a transparent agent is applied to a part of a base paper, the transparent paper is impregnated with the transparent agent to form a transparent window, and the base paper is made into a bag with a window. ,
As the base paper, single gloss bleached kraft paper having a basis weight of 50 to 110 g / m ² is used.
As the clearing agent, a clearing agent having a viscosity adjusted to 200 to 2000 cps (35 ° C.) is used,
Using at least one flexographic printing plate selected from the group consisting of a flexographic resin plate having a plurality of cuts formed on the surface and a flexographic sponge plate,
Production of a packaging bag with a window for applying the clearing agent to a part of the base paper by flexographic printing the clearing agent on the base paper using the flexographic printing plate impregnated with the clearing agent. Method.   The method for manufacturing a packaging bag with a window according to claim 9, wherein a flexographic resin plate having a plurality of cuts formed on a surface thereof is used as the flexographic printing plate. As the clearing agent, a UV curable clearing agent containing a (meth) acrylate monomer and a photopolymerization initiator, the viscosity of which is adjusted to 200 to 400 cps (35 ° C.),
The manufacturing method of the packaging bag with a window of Claim 9 or 10 which apply | coats the said UV curable transparent agent to a part of said base paper, impregnates the said base paper with the said transparentizing agent, and then irradiates an ultraviolet-ray. As the clearing agent, a rosin aqueous clearing agent having a viscosity adjusted to 1000 to 2000 cps (35 ° C.) is used.
The method for producing a packaging bag with a window according to claim 9 or 10, wherein the rosin-based aqueous clearing agent is applied to a part of the base paper, the base paper is impregnated with the clearing agent, and then heated.   The transparent agent is applied to a part of the base paper, the base paper is impregnated with the transparent agent, and then the transparent agent is applied again to a part of the base paper, and the transparent agent is applied to the base paper. The manufacturing method of the packaging bag with a window as described in any one of Claims 9-12 which impregnates. By forming a colored printing on the surface of the base paper to form a colored portion,
Then, the manufacturing method of the packaging bag with a window as described in any one of Claims 9-13 which apply | coats the said transparentizing agent on the back surface of the said base paper so that it may overlap with the said coloring part.

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