JP5286458B2 - Manufacturing method, manufacturing apparatus and packaging bag for packaging bag material - Google Patents

Description

  The present invention relates to a method for manufacturing a packaging bag material, a manufacturing apparatus, and a packaging bag.

  The packaging bag is formed of a thermoplastic resin film such as polyolefin, but since many of these resins are hydrophobic, it is difficult to print on the surface well. Therefore, conventionally, in order to improve printability, surface treatment of a thermoplastic resin film by corona discharge or the like has been performed (see, for example, Patent Document 1).

JP 2000-296666 A

  However, the conventional surface treatment imparts excellent printing characteristics to the treated surfaces, but it is difficult to fuse the surfaces together, and even if they are fused, the bonding force is weak and easily peels off. There is a problem that it ends up.

  The present invention has been made in view of the above circumstances, and is manufactured by a method for manufacturing a packaging bag material, a manufacturing apparatus for a packaging bag material, and a manufacturing method that are excellent in the balance between printing characteristics and fusing properties. It aims at providing the packaging bag formed from the material for packaging bags.

  The present inventors have found that printing properties and fusing properties can be adjusted as desired by performing surface treatment via active oxygen generated by ultraviolet irradiation, and have completed the present invention. Specifically, the present invention provides the following.

(1) A method for producing a packaging bag material,
Arrange at least one surface of the thermoplastic resin film in an atmosphere containing oxygen or ozone,
A production method comprising a step of performing a surface treatment by irradiating the oxygen or ozone with ultraviolet rays and exposing at least one surface of the thermoplastic resin film to the generated active oxygen.

  (2) The manufacturing method according to (1), wherein the ozone is generated by placing at least one surface of a thermoplastic resin film in an atmosphere containing oxygen and irradiating the oxygen with ultraviolet rays.

  (3) The production method according to (1) or (2), wherein the ultraviolet irradiation is performed intermittently with a non-irradiation period interposed therebetween.

  (4) The production method according to (1) or (2), wherein the irradiation with the ultraviolet light is continuously performed without a non-irradiation period.

  (5) The manufacturing method according to any one of (1) to (4), further including a step of printing on the surface-treated surface.

  (6) The manufacturing method according to any one of (1) to (5), wherein the thermoplastic resin is a polyolefin resin.

(7) A device for manufacturing a packaging bag material,
Ultraviolet irradiation means for irradiating ultraviolet light to a space where at least one surface of the thermoplastic resin film is exposed;
A conveying means for moving the thermoplastic resin film relative to the space.

  (8) The manufacturing apparatus according to (7), wherein the ultraviolet irradiation means can irradiate ultraviolet rays having a plurality of wavelengths.

  (9) The manufacturing apparatus according to (7) or (8), further comprising selection means for selecting whether to irradiate or not irradiate ultraviolet rays by the ultraviolet irradiation means.

  (10) The manufacturing apparatus according to any one of (7) to (9), wherein a plurality of the ultraviolet irradiation means are provided at a predetermined distance.

  (11) A packaging bag formed from a packaging bag material produced by the production method according to any one of (1) to (6).

  (12) The packaging bag according to (11), wherein the surface-treated surface is located outside.

  (13) The packaging bag according to (11) or (12), further comprising a printed layer positioned on the surface-treated surface.

  (14) The packaging bag according to any one of (11) to (13), wherein the surface-treated portions are fused together.

  (15) The packaging bag according to (14), wherein the surface-fused portion between the surface-treated portions closes a non-opening opening.

  (16) The packaging bag according to (14), wherein the portion that is fused with the surface-treated portions closes the opening for opening.

  According to the present invention, since the surface treatment is performed via the active oxygen generated by the ultraviolet irradiation, the printing characteristics and the fusing property can be adjusted as desired by appropriately selecting the conditions. Thereby, the packaging bag material excellent in the balance of a printing characteristic and a melt | fusion property can be manufactured.

It is a figure which shows the manufacturing apparatus of the material for packaging bags which concerns on one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, this embodiment does not limit the present invention.

  The packaging bag material manufacturing apparatus 10 according to the present invention includes an ultraviolet treatment device 20 and a transport unit 30.

  The ultraviolet treatment apparatus 20 includes an ultraviolet irradiation unit 23 as an ultraviolet irradiation unit, and the ultraviolet irradiation unit 23 irradiates the space S where at least one surface (upper surface in FIG. 1) of the thermoplastic resin film P is exposed with ultraviolet rays. To do. Oxygen or ozone is present in the space S, and active oxygen generated from oxygen or ozone acts on one surface of the thermoplastic resin film P, and is subjected to surface treatment. By appropriately selecting the conditions, the printing characteristics and the fusing property can be adjusted as desired. In this embodiment, only one surface of the thermoplastic resin film P is processed. However, the present invention is not limited to this, and both surfaces may be processed or only a part of the surface may be processed (in this case) In this case, the part not to be treated is protected with a coating or the like).

  The ultraviolet treatment apparatus 20 in the present embodiment has a housing 21 that surrounds the ultraviolet irradiation unit 23, and the diffusion of active oxygen is suppressed by the housing 21, and active oxygen is efficiently accumulated in the space S. be able to. Moreover, the housing | casing 21 shields an ultraviolet-ray and is advantageous also at the point which can improve surrounding safety more. If necessary, a suction device (duct) is provided in a portion of the housing 21 that communicates with the outside air (a portion in which the thermoplastic resin film P enters and a portion in which the thermoplastic resin film P enters and exits in FIG. 1), and ozone gas is sucked by this suction device. Thus, the outflow of ozone gas to the outside of the ultraviolet treatment device 20 may be suppressed.

  By changing the distance from the ultraviolet irradiation part 23 (light source) to the thermoplastic resin film P, the ozone gas concentration on the surface of the thermoplastic resin film P increases or decreases. You can also adjust with. This distance (shortest distance) may be appropriately selected according to the output of the light source, but generally it may be about 1 to 10 cm, and in the case of “SUV110GS-36” (manufactured by Sen Special Light Company), about 3 cm is preferable. .

  The conveyance unit 30 moves the thermoplastic resin film P relative to the space S. By adjusting the movement, the time during which the thermoplastic resin film P is exposed to active oxygen can be set as appropriate. In addition, although the conveyance part 30 in this embodiment is a roller which conveys the thermoplastic resin film P, it is not restricted to this, You may move the housing | casing 21. FIG.

  The generation of active oxygen from ozone by ultraviolet light is a conventionally known technique per se and may be performed according to a conventional method. Specifically, ozone may be irradiated with ultraviolet light having a wavelength of 254 nm. Here, ozone may be generated by irradiating ultraviolet rays having a wavelength of 240 nm or less (usually more than 175 nm) to oxygen, or may be supplied from the outside. Note that active oxygen can be directly generated from oxygen by irradiating oxygen with an ultraviolet ray having a wavelength of 175 nm or less.

  In the present embodiment, the ultraviolet irradiation unit 23 can irradiate ultraviolet rays having a plurality of wavelengths, and the space S is open to the outside air. The ultraviolet irradiation unit 23 irradiates the space S with 185 nm ultraviolet rays to generate ozone from oxygen in the air, and the ultraviolet irradiation unit 23 irradiates ozone with ultraviolet rays having a wavelength of 254 nm to generate active oxygen. . In addition, since the light source suitable for ultraviolet irradiation of each wavelength is conventionally well-known, description is abbreviate | omitted.

  Irradiation of ultraviolet rays (herein, irradiation of ultraviolet rays refers to irradiation of ultraviolet rays to each part of the thermoplastic resin film P, not the entire thermoplastic resin film P) is performed intermittently with a non-irradiation period in between. Alternatively, it may be performed continuously without any non-irradiation period. Although it depends on the material of the thermoplastic resin film P to be used, in general, since the former can highly suppress a decrease in fusion power, it is useful for, for example, a portion that blocks an opening for non-opening, and the latter is a decrease in fusion power Therefore, it is useful for a portion that closes the opening for opening.

  Conventionally, a portion having an appropriate fusing force is laminated when a film layer that is difficult to fuse and a film layer that is easy to fuse are laminated, or a film that is easy to fuse is laminated, and heated when heat-sealing. In addition, it has been produced by intentionally reducing the fusion force by a complicated method of alternately performing non-heating. However, according to the method of the present invention, it is possible to easily adjust the fusing property simply by appropriately selecting the ultraviolet irradiation conditions.

  In general, the printing characteristics improve as the total irradiation time or each irradiation time becomes longer, and the fusing force tends to decrease when the total irradiation time or each irradiation time is high to some extent but excessively long. For this reason, when it is desired that both the printing characteristics and the fusing force are high, it is preferable to shorten each irradiation time while increasing the total irradiation time and interposing many non-irradiation times. In addition, when it is desired that the printing characteristics are high but the fusing force is moderate, it is preferable to increase the total irradiation time and reduce the number of times of non-irradiation time. Specific irradiation time is not specifically limited, According to the raw material of the thermoplastic resin film P to be used, you may set suitably.

  The length of each non-irradiation time may be appropriately set according to the material of the thermoplastic resin film P to be used, but is generally 0.1 times or more (for example, about 1 time) of each irradiation time. That's fine.

  In the present embodiment, a plurality of ultraviolet irradiation units 23a and 23b are provided at a predetermined distance in the transport direction (the arrow direction in FIG. 1). The irradiation time and the non-irradiation time can be repeated according to the number of the ultraviolet irradiation units 23, and the ratio of the irradiation time and the non-irradiation time can be adjusted according to the length in the transport direction of the space S and the predetermined distance. However, the present invention is not limited to this, and ultraviolet irradiation and non-irradiation may be selected by controlling the ultraviolet irradiation unit 23 to operate and deactivate. The means for performing such selection may be any conventionally known control device.

  Examples of the thermoplastic resin used in the present invention include ethylene resins such as high density polyethylene and low density polyethylene, polyolefin resins such as propylene resin, polymethyl-1-pentene, ethylene-cyclic olefin copolymer, nylon-6, Polyamide resins such as nylon-6,6, nylon-6,10, nylon-6,12, etc., thermoplastic polyester resins such as polyethylene terephthalate and copolymers thereof, polyethylene naphthalate, aliphatic polyester, polycarbonate, atactic One type or two or more types of thermoplastic resins such as polystyrene, syndiotactic polystyrene, polyphenylene sulfide and the like can be mentioned. Among these, a non-polar polyolefin resin is preferable in that the present invention is more useful, and more specifically an ethylene resin.

  The manufacturing method of the present invention may further include a step of printing on the surface-treated surface. Since the surface surface-treated as described above has excellent printing characteristics, a strong printing layer can be formed. The printing method is not particularly limited, and may be gravure printing or the like.

  This invention includes the packaging bag formed from the above-mentioned packaging bag material. The packaging bag is generally formed by partially fusing a packaging bag material. Since deterioration of the fusing property of the surface-treated surfaces is suppressed, the portion to be fused is between the surface-treated surfaces, between the non-surface-treated surfaces, or the surface-treated surface. The surface may be any surface that is not surface-treated, and may be appropriately selected according to the shape of the bag (how to fold the packaging bag material) and the use of the fused portion.

  The portion fused between the surface-treated portions may be one that closes a non-opening opening that is not generally opened like the bottom of the bag. In this case, since it is desirable to join the surface-treated parts with a strong fusing force, it is preferable to use a packaging bag material irradiated with ultraviolet rays under a condition in which each irradiation time is short with a lot of non-irradiation time in between. Moreover, the part fused by the surface-treated parts may block the opening for opening that is generally opened like the upper side of the bag. In this case, since it is desirable to join the surface-treated parts with an appropriate fusion force, it is for packaging bags irradiated with ultraviolet rays under the condition that the total irradiation time is lengthened and the non-irradiation time is not sandwiched or the number of times of sandwiching is small. It is preferable to use a material.

  Since the printing layer is usually formed on the outside, it is preferable that the surface-treated surface having excellent printing characteristics is located on the outside, but it may be located on the inside. The printed layer is preferably formed on the surface-treated surface, but may be on the surface that has not been surface-treated. In addition, formation of a printing layer may be performed in the manufacturing process of the material for packaging bags as mentioned above, and may be performed with respect to a packaging bag.

  In the packaging bag material manufacturing apparatus 10 shown in FIG. 1, “SUV110GS-36” (manufactured by Sen Special Light Company) was used as a light source, and preliminary irradiation was performed for about 30 to 60 minutes in order to stabilize the output of the light source. Thereafter, the following examples were carried out.

<Example 1>
A high-density polyethylene film was used as the thermoplastic resin film, and ultraviolet rays having wavelengths of 185 nm and 254 nm were irradiated for 60 seconds toward the film at a position 3 cm away from the light source to produce a packaging bag material.

<Example 2>
For packaging bags in the same procedure as in Example 1, except that 20 seconds of irradiation, 20 seconds of non-irradiation (light source off), 20 seconds of irradiation, 20 seconds of non-irradiation, and 20 seconds of irradiation were sequentially performed. The material was manufactured.

<Example 3>
A packaging bag material was produced in the same procedure as in Example 1 except that ultraviolet rays were irradiated for 120 seconds.

<Example 4>
A packaging bag material was produced in the same procedure as in Example 1 except that a low-density polyethylene film was used as the thermoplastic resin film and ultraviolet rays were irradiated for 40 seconds.

<Example 5>
A packaging bag material was manufactured in the same procedure as in Example 4 except that irradiation for 20 seconds, non-irradiation for 20 seconds (light source off), and irradiation for 20 seconds were sequentially performed.

<Example 6>
For packaging bags in the same procedure as in Example 4 except that irradiation for 13 seconds, non-irradiation for 13 seconds (light source turned off), irradiation for 13 seconds, non-irradiation for 13 seconds, and irradiation for 13 seconds were sequentially performed. The material was manufactured.

<Example 7>
Except for 10 seconds irradiation, 10 seconds non-irradiation (light source off), 10 seconds irradiation, 10 seconds non-irradiation, 10 seconds irradiation, 10 seconds non-irradiation, 10 seconds irradiation A packaging bag material was produced in the same procedure as in Example 4.

(Comparative Example 1)
A discharge wattage of 400 W and a discharge wire length of 300 mm, a high-density polyethylene film was placed at a position 1 mm away from the electrode, and corona discharge was performed at a film transport speed of 33 m / min to produce a packaging bag material.

(Comparative Example 2)
A packaging bag material was produced in the same procedure as in Comparative Example 1 except that the discharge wattage was 300 W and a low-density polyethylene film was used.

[Evaluation]
A printing layer of a polyamide resin gravure ink was formed on the packaging bag material produced in the examples and comparative examples by a gravure printing machine. The printed layer was rubbed back and forth 20 times with a paper waste while applying an excess of 2 kg, and the subsequent state was evaluated according to the following criteria. The results are shown in Table 1.
◎: No damage was confirmed on the printed layer. ○: Scratch was confirmed on the printed layer. △: The printed layer was slightly peeled. ×: The printed layer was severely peeled.

Of the packaging bag materials produced in the examples and comparative examples, the surface-treated surfaces were bonded together at 200 ° C. for 1 second and heat-sealed. The fused portions were pulled with the same force in the direction of separating from each other, and the state at that time was evaluated according to the following criteria. The results are shown in Table 1.
◎: There was no change in the fused part, and the film was broken. ○: The fused part was peeled off and the film was broken. △: The fused part was peeled before the film was stretched and broken. Peeled

  A 1.5 μL water droplet was dropped on the surface treated surface, and the contact angle was measured by a usual method using a contact angle meter “DM500” (manufactured by Kyowa Interface Science Co., Ltd.). Further, the temperature was raised from 30 ° C. to 150 ° C. at a rate of 5 ° C./min using the reference material as alumina powder, and the glass transition temperature was measured by a usual method using a thermal analyzer “DSC8230” (manufactured by Rigaku Corporation). did. The results are shown in Table 1.

  As shown in Table 1, the printing characteristics of the untreated product were poor and the fusing property was poor in the comparative example, whereas the balance between the printing characteristics and the fusing property was excellent in the examples. Thereby, it was confirmed that the packaging bag material which is excellent in the balance of a printing characteristic and a melt | fusion property can be manufactured by surface-treating through the active oxygen produced | generated by ultraviolet irradiation. This is because corona discharge gives excessive energy to the film and destroys the molecules, while ultraviolet irradiation reduces the energy given to the film and damages the molecules so that the original fusion property is maintained. It is speculated that.

  In contrast to Examples 1 and 2, the high-density polyethylene film can further improve printing characteristics by continuously irradiating with ultraviolet rays without interposing non-irradiation time, while the presence or absence of non-irradiation time has a great influence on the fusion property. (It is presumed that the change in the glass transition temperature is small). It was also found from the comparison between Examples 1 and 3 that the high-density polyethylene film can adjust the fusing force according to the length of the total irradiation time.

  By comparing Examples 4 to 7, the low density polyethylene film can adjust the fusing force according to the number of non-irradiation times and / or the length of each irradiation time (according to the large change in glass transition temperature). I guess). It was also found that the low-density polyethylene film can adjust the fusing force depending on the total irradiation time.

DESCRIPTION OF SYMBOLS 10 Manufacturing apparatus of packaging bag material 20 Ultraviolet processing apparatus 21 Case 23 Ultraviolet irradiation part (ultraviolet irradiation means)
30 Conveying part (conveying means)
P film S space

Claims (13)

A method for producing a packaging bag material comprising:
Arranging at least the opening for opening or opening of the packaging bag of the thermoplastic resin film in an atmosphere containing oxygen or ozone,
A manufacturing method comprising a step of performing a surface treatment by irradiating the oxygen or ozone with ultraviolet rays and exposing the portion to generated active oxygen. The said ozone is the manufacturing method of Claim 1 which arrange | positions the said part in the atmosphere containing oxygen, and irradiates the said ultraviolet to ultraviolet rays.   The manufacturing method according to claim 1, wherein the irradiation of the ultraviolet rays is intermittently performed with a non-irradiation period interposed therebetween.   The production method according to claim 1 or 2, wherein the ultraviolet irradiation is continuously performed without any non-irradiation period. The manufacturing method according to claim 1, further comprising a step of printing on the surface-treated portion .   The manufacturing method according to claim 1, wherein the thermoplastic resin is a polyolefin resin. A method for manufacturing a packaging bag, comprising:
Using the packaging bag material manufactured by the manufacturing method according to any one of claims 1 to 6, among the surface-treated portions, the portions to be the non-opening opening or the opening for opening of the packaging bag are fused together. The manufacturing method which has a process. The manufacturing method according to claim 7, wherein a portion fused between the surface-treated portions closes a non-opening opening. The manufacturing method according to claim 7, wherein a portion fused between the surface-treated portions closes an opening for opening.   The packaging bag formed from the material for packaging bags manufactured with the manufacturing method in any one of Claim 1 to 6. The packaging bag according to claim 10, wherein a part of the surface-treated portion is located outside. The packaging bag of Claim 10 or 11 further provided with the printing layer located on a part of said surface-treated part . The packaging bag according to any one of claims 10 to 12, wherein the surface-treated portions are fused together.

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