JP2022046080A - Packaging bag - Google Patents

Abstract

To provide a packaging bag capable of firstly sufficiently preventing polyethylene from being eluted to ink; of secondly preventing delamination between an intermediate layer and an innermost layer; and of thirdly sufficiently preventing the polyethylene from being eluted to washing liquid.SOLUTION: A laminate sheet 2 of a packaging bag comprises a substrate layer 21 arranged outside, a barrier layer 22 containing a metal element arranged inside the substrate layer 21, an intermediate layer 23 containing polyamide arranged inside the barrier layer 22, an innermost layer 24 containing polyethylene arranged inside the barrier layer 22. The polyethylene of the innermost layer 24, whose melting point is 120°C or more and 129°C or less is made of single polyethylene whose melting point has one peak.SELECTED DRAWING: Figure 2

Description

The present invention relates to a packaging bag containing ink containing a solvent used in an industrial inkjet printer or the like.

Conventionally, as a packaging bag used in an industrial inkjet printer or the like and containing an ink containing a solvent, a packaging bag made of a laminated sheet in which a predetermined resin layer is laminated is known. Specifically, this packaging bag is arranged inside a base material layer containing polyethylene terephthalate arranged outside, a barrier layer containing a metal element arranged inside the base material layer, and the inside of the barrier layer. It includes an intermediate layer containing a polyamide layer and an innermost layer containing polyethylene arranged inside the barrier layer.

However, the ink containing a solvent contains, for example, diethylene glycol diethyl ether, γ-butyrolactone, a pigment and a binder resin, and when the ink is contained in the packaging bag having the above constitution, the polyethylene contained in the innermost layer elutes into the ink. In some cases. When polyethylene elutes into ink in this way, there is a risk that problems such as clogging of the inkjet head and ink path of the inkjet printer may occur.

Then, as a solution to such a difficulty, a packaging bag in which the melting point of polyethylene in the innermost layer is set to 120 ° C. or higher has been proposed (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2019-104178

However, the innermost polyethylene used in the conventional packaging bag having the above structure is generally produced by blending a plurality of types of polyethylene having different melting points in order to improve the processability of polyethylene. Therefore, as shown in FIG. 6A, there are a plurality of peaks of the melting point of polyethylene, and even if the average melting point of polyethylene is 120 ° C. or higher, polyethylene having a melting point of 120 ° C. or lower exists. Therefore, there is a problem that the elution of polyethylene into the ink cannot be sufficiently suppressed.

Further, even if the elution of polyethylene into the ink is suppressed to some extent by setting the average melting point of polyethylene in the innermost layer to 120 ° C. or higher, the intermediate layer containing polyamide and the innermost layer containing polyethylene are directly dried by dry laminating. In the laminated structure, delamination (delamination) occurs between the intermediate layer and the innermost layer, and there is a problem that the strength of the packaging bag may decrease, leading to bag breakage, ink leakage, and significant deterioration in appearance during transportation. there were.

Further, especially in an industrial inkjet printer, a packaging bag containing a cleaning liquid is attached to the printer and the ink path of the printer is regularly cleaned with the cleaning liquid. At this time, the packaging bag contains ink. Ink is often used with the same configuration as the printed packaging bag. This cleaning solution contains a mixture of an organic solvent such as dipropylene glycol monomethyl ether, NN-dimethylformaldehyde, and diethylene glycol diethyl ether and a surfactant, and polyethylene contained in the innermost layer and other resin layers is contained in the cleaning solution. There was a problem that there was a risk of elution.

The present invention has been made in view of the above problems, firstly, it is possible to sufficiently suppress the elution of polyethylene into the ink, and secondly, it is possible to prevent delamination between the intermediate layer and the innermost layer. Thirdly, it is an object of the present invention to provide a packaging bag capable of sufficiently suppressing the elution of polyethylene into the cleaning liquid.

The present invention is a packaging bag in which a laminated sheet in which a plurality of resin layers are laminated is manufactured in order to achieve the above object and contains ink containing a solvent, and the laminated sheet is laminated on the outside. A base material layer, a barrier layer containing a metal element laminated inside the base material layer, an intermediate layer containing a polyamide laminated inside the barrier layer, and a laminate inside the barrier layer. The innermost layer of polyethylene is characterized by having a melting point of 120 ° C. or higher and 129 ° C. or lower, and having a peak melting point of one single polyethylene.

According to this, since the innermost layer of the laminated sheet contains only a single polyethylene having a peak melting point and does not contain a plurality of polyethylenes having different melting points, it is possible to sufficiently suppress the elution of polyethylene into the ink. can.

Further, the intermediate layer and the innermost layer are extruded through a special adhesive layer containing polyethylene having a melting point of less than 120 ° C. in a state where the polyolefin-based adhesive is applied to the surface of the intermediate layer on the innermost layer side. It is better to be laminated by laminating. According to this, since the intermediate layer and the innermost layer are surely adhered to each other via the special adhesive layer, in addition to the effect of suppressing the elution of polyethylene in the innermost layer into the ink, the delamination between the intermediate layer and the innermost layer is performed. It is possible to prevent the occurrence of (delamination), and by extension, it is possible to suppress bag breakage, ink leakage, and deterioration of appearance during transportation by improving the strength of the packaging bag.

Further, the innermost layer has a melting point of 120 ° C. or higher and 129 ° C. or lower, and has a first innermost layer and a second innermost layer containing polyethylene having a melting point peak of one single polyethylene, and polyamide. It is preferable that the third innermost layer containing the innermost layer is provided, and the first innermost layer and the second innermost layer are laminated by coextrusion in a manner of sandwiching the third innermost layer. According to this, in addition to the effect of suppressing the elution of polyethylene in the innermost layer into the ink, the effect of preventing the occurrence of delamination (delamination) between the intermediate layer and the innermost layer and the effect of suppressing the elution of polyethylene in the cleaning liquid. It is possible to improve the quality of the entire packaging bag.

Further, the laminated sheet according to the present invention is a laminated sheet in which a plurality of resin layers are laminated, which is used for a packaging bag containing ink containing a solvent, and is the base material layer laminated on the outside and a base material. A barrier layer containing a metal element laminated inside the layer, an intermediate layer containing a polyamide laminated inside the barrier layer, and an innermost layer containing polyethylene laminated inside the barrier layer. The innermost layer of polyethylene is characterized by having a melting point of 120 ° C. or higher and 129 ° C. or lower, and having a peak melting point of one single polyethylene.

According to this, since the polyethylene in the innermost layer is a single polyethylene having one peak melting point and does not contain a plurality of polyethylenes having different melting points, it is possible to sufficiently suppress the elution of polyethylene into the ink. ..

According to the present invention, the polyethylene in the innermost layer is a single polyethylene having one peak melting point and does not contain a plurality of polyethylenes having different melting points, so that the elution of polyethylene into the ink can be sufficiently suppressed. can.

It is a perspective view of the packaging bag which concerns on embodiment of this invention. It is sectional drawing of (a) the packaging bag which concerns on 1st Embodiment, (b) the packaging bag which concerns on 2nd Embodiment, and (c) the laminated sheet of the packaging bag which concerns on 3rd Embodiment. It is a table which shows the test result which concerns on Example 1. FIG. It is a table which shows the test result which concerns on Example 2. It is a table which shows the test result which concerns on Example 3. FIG. It is a graph which shows (a) the peak of the melting point of the innermost layer of the conventional packaging bag, and (b) the peak of the melting point of the innermost layer of the packaging bag which concerns on this invention.

<First Embodiment>
Next, the first embodiment of the packaging bag according to the present invention will be described with reference to FIGS. 1 and 2 (a).

As shown in FIG. 1, the packaging bag 1 according to the present embodiment is a packaging bag containing ink used in an industrial inkjet printer or the like. The packaging bag 1 is composed of a laminated sheet 2 in which a plurality of resin layers are laminated, and is provided with a spout 3 which is connected to an industrial inkjet printer or the like to discharge ink. The ink contains, for example, diethylene glycol diethyl ether, γ-butyrolactone, a pigment and a binder resin.

As shown in FIG. 2, the laminated sheet 2 has a base material layer 21 laminated on the outside, a barrier layer 22 containing a metal element laminated on the inside of the base material layer 21, and the inside of the barrier layer 22. The intermediate layer 23 containing the laminated polyamide and the innermost layer 24 (sealant layer) containing polyethylene arranged inside the barrier layer 22 are provided.

The base material layer 21 is a layer that serves as a base material for the laminated sheet 2, and is made of a resin containing polyester, polyamide, or polyolefin. Examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate and the like. Examples of the polyamide include nylon 6, nylon 6,6, nylon 9, nylon 11, nylon 12, nylon 6/66, nylon 66/610, nylon MXD6 and the like. Further, examples of the polyolefin include polyethylene and polypropylene. The outermost layer 21 is preferably stretched, and more preferably biaxially stretched, which is excellent in mechanical strength, crack resistance, and heat resistance. The outermost layer 21 is preferably 5 μm to 25 μm in thickness.

The barrier layer 22 is a layer containing a metal element that imparts a barrier property to the laminated sheet 2, and is made of, for example, an aluminum foil. The barrier layer 22 is preferably 6 μm to 50 μm in thickness. According to this, the packaging bag 1 can be provided with a gas barrier property, a light shielding property, and the like by the barrier layer 22. For convenience of explanation, the thickness of the barrier layer 22 is shown in FIG. 2 to be larger than the actual thickness.

The intermediate layer 23 is a resin layer located in the middle of the laminated sheet 2 and is made of a resin containing a polyamide. Examples of the polyamide include nylon 6, nylon 6,6, nylon 9, nylon 11, nylon 12, nylon 6/66, nylon 66/610, nylon MXD6 and the like. The thickness of the intermediate layer 23 is preferably 15 μm to 25 μm.

The innermost layer 24 is a layer that is heat-sealed with the innermost layer 24 of another laminated sheet 2 when the laminated sheet 2 is made into a bag, and is made of a resin containing polyethylene. Further, the innermost layer 24 may contain a propylene / ethylene block copolymer, or may further contain a thermoplastic elastomer. In this case, the impact resistance and the piercing resistance of the packaging bag 1 can be improved. The innermost layer 24 preferably has a thickness of 40 μm to 180 μm.

As shown in FIG. 6B, the polyethylene of the innermost layer 24 has a melting point of 120 ° C. or higher and 129 ° C. or lower, and has a melting point peak of one single polyethylene, for example, low density polyethylene (LDPE). , Linear low density polyethylene (LLDPE) and the like.

According to this, since the innermost layer 24 contains only a single polyethylene having a peak melting point and does not contain a plurality of polyethylenes having different melting points, it is possible to sufficiently suppress the elution of polyethylene into the ink.

Even if the melting point of polyethylene is 130 ° C. or higher, the elution of polyethylene into the ink can be sufficiently suppressed, but in that case, when the laminated sheet 2 is bonded by heating at the time of making the packaging bag 1. The melting point of polyethylene is preferably 129 ° C. or lower because it requires a high temperature of 130 ° C. or higher and the workability is lowered.

<Second embodiment>
Next, a second embodiment of the packaging bag according to the present invention will be described with reference to FIGS. 1 and 2 (b). In the following, only the configurations different from the above-described embodiment will be described, and the same configurations will be omitted and the same reference numerals will be given.

The packaging bag 1 according to the present embodiment is the packaging bag 1 according to the first embodiment, and a special adhesive layer 25 is further provided between the intermediate layer 23 and the innermost layer 24. Specifically, the intermediate layer 23 and the innermost layer 24 are specially bonded containing polyethylene having a melting point of less than 120 ° C. in a state where the polyolefin-based adhesive is applied to the surface of the intermediate layer 23 on the innermost layer 24 side. It is laminated by extrusion laminating through the layer 25. At this time, in order to ensure that the intermediate layer 23 and the innermost layer 24 are laminated via the special adhesive layer 25, the special adhesive layer 25 is in a heated state immediately after being extruded, and the intermediate layer 23 and the innermost layer are used. It is better to stack 24.

According to this, since the intermediate layer 23 and the innermost layer 24 are surely adhered to each other via the special adhesive layer 25, in addition to the effect of suppressing the elution of polyethylene of the innermost layer 24 into the ink, the intermediate layer 23 and the innermost layer are formed. It is possible to prevent the occurrence of delamination (delamination) between 24 and, by extension, by improving the strength of the packaging bag 1, it is possible to suppress bag breakage, ink leakage, and deterioration of appearance during transportation.

<Third embodiment>
Next, a third embodiment of the packaging bag according to the present invention will be described with reference to FIGS. 1 and 2 (c). In the following, only the configurations different from the above-described embodiment will be described, and the same configurations will be omitted and the same reference numerals will be given.

The packaging bag 1 according to the present embodiment is the packaging bag 1 according to the first embodiment, and the innermost layer 24 is further composed of three layers. Specifically, the innermost layer 24 is arranged on the outside, and the first innermost layer 241 containing polyethylene having a melting point of 120 ° C. or higher and 129 ° C. or lower and having a melting point peak of one single polyethylene. And a second innermost layer 242 and a third innermost layer 243 containing polyamide, by coextrusion in such a manner that the first innermost layer 241 and the second innermost layer 242 sandwich the third innermost layer 243. It is laminated.

According to this, the component of the ink that damages the laminating agent of the intermediate layer 23 and the innermost layer 24 by the third innermost layer 243 laminated between the first innermost layer 241 and the second innermost layer 242. Since the permeation of the ink is blocked, delamination of the intermediate layer 23 and the innermost layer 24 can be prevented.

Further, even when the cleaning liquid is contained in the packaging bag 1, since the melting point of the polyethylene in the innermost layer 24 is 120 ° C. or higher, it is possible to suppress the elution of polyethylene into the cleaning liquid.

Therefore, in addition to the effect of suppressing the elution of polyethylene in the innermost layer 24 into the ink, the effect of preventing the occurrence of delamination (delamination) between the intermediate layer 23 and the innermost layer 24, and the effect of polyethylene in the innermost layer 24 in the cleaning liquid. The effect of suppressing the elution of polyethylene is also obtained, and the quality of the entire packaging bag 1 can be improved.

Next, the results of evaluation of the packaging bag 1 according to the present invention and the conventional packaging bag will be described.

<Example 1>
In the first embodiment, regarding the packaging bag 1 and the conventional packaging bag 1 according to the first embodiment of the present invention, the innermost layer 24 (polyethylene film (1) to (5)) in the laminated sheet 2 of the packaging bag 1 is configured. ) Was evaluated for the elution state of polyethylene with respect to the evaluation solvent A.

(Evaluation target)
・ Polyethylene film (1) (conventional packaging bag)
It contains two polyethylenes having different melting points (108 ° C./119 ° C.) and has an average melting point of 116 ° C.
・ Polyethylene film (2) (conventional packaging bag)
It contains two polyethylenes having different melting points (113 ° C./121 ° C.) and has an average melting point of 120 ° C.
・ Polyethylene film (3) (conventional packaging bag)
It contains three polyethylenes having different melting points (107 ° C./121 ° C./125 ° C.) and has an average melting point of 123 ° C.
-Polyethylene film (4) (Packaging bag 1 according to the present invention)
Contains a single polyethylene with a melting point (124 ° C).
-Polyethylene film (5) (Packaging bag 1 according to the present invention)
Contains a single polyethylene having a melting point (127 ° C.).

(Evaluation solvent A)
As the evaluation solvent A, a solvent-based inkjet ink containing 78.5% by mass of diethylene glycol diethyl ether, 10% by mass of γ-butyrolactone, 3.5% by mass of pigment, and 8% by mass of binder resin was prepared.

(Evaluation methods)
Each polyethylene film (1) to (5) was immersed in the evaluation solvent A, stored at 60 ° C. for 1 week, and then stored at room temperature for 1 day. Then, 30 mL of the evaluation solvent A was extracted and filtered by its own weight with a 3000 mesh stainless filter (opening 5 μm). At this time, the time required for all the evaluation solvents A to permeate the filter (filtration time) was measured. If polyethylene elutes when stored at 60 ° C., polyethylene precipitates when stored at room temperature. When polyethylene is deposited, the filtration time becomes long, so the filtration time is an index of the elution state of polyethylene. Therefore, those having a filtration time of a predetermined time (120 seconds) or less were designated as "○ (good)", and those having a filtration time exceeding the predetermined time were designated as "x (poor)".

(Evaluation results)
FIG. 3 shows the evaluation results of the polyethylene films (1) to (5) according to this example. Among the polyethylene films (1) to (3) containing polyethylene having a plurality of melting points used in the conventional packaging bag 1, not only polyethylene 1 having an average melting point of 116 ° C. but also polyethylenes 2 and 3 having an average melting point of 120 ° C. or higher are used. However, the filtration time exceeded a predetermined time, and polyethylene was often eluted into the evaluation solvent A. On the other hand, the polyethylene films (4) and (5) containing one melting point polyethylene used in the packaging bag 1 of the present invention and having a melting point of 120 ° C. or higher are evaluated because the filtration time is less than a predetermined time. The elution of polyethylene into the solvent A was small and good.

From this, when the polyethylene film (innermost layer 24) contains a plurality of types of polyethylene having different melting points, the elution of polyethylene into the ink is sufficiently suppressed even if the average melting point of the polyethylene is 120 ° C. or higher and 129 ° C. or lower. It was confirmed that it could not be done. On the other hand, when the melting point of the polyethylene film (innermost layer 24) is 120 ° C. or higher and 129 ° C. or lower and the melting point contains a single polyethylene, it is confirmed that the elution of polyethylene into the ink is sufficiently suppressed. Was done.

<Example 2>
In Example 2, the packaging bag 1 and the conventional packaging bag according to the present invention are evaluated by appearance inspection, interlayer strength measurement, drop test, and transportation test of the laminated sheet 2 (film configurations (1) to (3)). went.

(Evaluation target)
・ Film composition (1) (Compatible with conventional packaging bags)
PET / AL / NY / LLDPE
PET (base material layer 21): polyethylene terephthalate (12 μm)
AL (barrier layer 22): aluminum (9 μm)
NY (intermediate layer 23): nylon (15 μm)
LLDPE (innermost layer 24): Polyethylene film (2) (150 μm) of Example 1
NY (intermediate layer 23) and LLDPE (innermost layer 24) are laminated by dry laminating.

-Film configuration (2) (corresponding to the packaging bag 1 of the second embodiment)
PET / AL / NY / PE / LLDPE
PET (base material layer 21): polyethylene terephthalate (12 μm)
AL (barrier layer 22): aluminum (9 μm)
NY (intermediate layer 23): nylon (15 μm)
PE (special adhesive layer 25): Polyethylene Melting point 105 ° C (30 μm)
LLDPE (innermost layer 24): Polyethylene film of Example 1 (4) (120 μm)
NY (intermediate layer 23) and LLDPE (innermost layer 24) are laminated by extrusion laminating via PE (special adhesive layer 25).

-Film configuration (3) (corresponding to the packaging bag 1 of the third embodiment)
PET / AL / NY / PE / coextruded layer PET (base material layer 21): polyethylene terephthalate (12 μm)
AL (barrier layer 22): aluminum (9 μm)
NY (intermediate layer 23): nylon (15 μm)
Coextruded layer (innermost layer 24): Polyethylene film (5) (150 μm) of Example 1.
The coextruded layer (innermost layer 24) is laminated by coextrusion in such a manner that the first innermost layer 241 (LLDPE 65 μm) and the second innermost layer 242 (LLDPE 65 μm) sandwich the third innermost layer 243 (nylon 15 μm). It was done.

(Evaluation solvent A)
As the evaluation solvent A, a solvent-based inkjet ink having the same components as in Example 1 was prepared.

(Evaluation methods)
Each packaging bag 1 of the above film configurations (1) to (3) is filled with 2000 mL of the evaluation solvent A, stored at a temperature of 60 ° C. for 8 weeks, and then the appearance inspection, interlayer strength measurement, and drop of each packaging bag 1 are performed. A test and a transportation test were performed 5 times each for comparative evaluation.

・ Appearance inspection After storage, the pouch surface condition such as delamination was visually confirmed (if there is no problem: 〇, if some delamination is seen: △, if severe delamination is seen: ×).

-Measurement of interlayer strength A film of 15 mm x 100 mm is cut out from each packaging bag 1 of the above film configurations (1) to (3), and the interlayer strength is obtained by T-type peeling at a rate of 10 mm / min (if it is 2N / 15 mm or more). Evaluated as normal)

・ Drop test From a height of 100 cm, a drop test was conducted for 3 cycles in a 23 ° C environment with the body → bottom as one cycle, and the presence or absence of bag breakage and liquid leakage was confirmed (bag breakage and liquid leakage occurred in the 3-cycle test). None: 〇, bag breakage / liquid leakage occurred during the test: ×)

・ Transportation test One round-trip airmail between Osaka and China (Jiangsu Province) (no bag rupture / leakage occurred: 〇, bag rupture / liquid leakage occurred: ×)

(Evaluation results)
FIG. 4 shows the evaluation results of each packaging bag 1 of the film configurations (1) to (3) according to the present embodiment.

The packaging bag 1 having the film configuration (1) had a lower interlayer strength than the packaging bag 1 having the film configurations (2) and (3). In addition, delamination was generally seen in the visual inspection. In addition, in the drop test, bag breakage and liquid leakage occurred during the evaluation test in all cases. Also, in the transportation test, bag breakage and liquid leakage occurred during transportation 3 times out of 5 times.

Further, the packaging bag 1 having the film configuration (2) had high interlayer strength. In addition, there were no problems in the appearance inspection, the drop test, and the transportation test, and the results were extremely good. It is considered that this is because the packaging bag 1 of the film configuration (2) has the intermediate layer 23 and the innermost layer 24 firmly laminated by extrusion laminating via the special adhesive layer 25.

Further, the packaging bag 1 having the film configuration (3) had a very high interlayer strength. In addition, there were no problems in the appearance inspection, the drop test, and the transportation test, and the results were extremely good. It is considered that this is because the third innermost layer 243 in the composition of the innermost layer 24 blocks the permeation of the component of the evaluation solvent A that causes delamination between the intermediate layer 23 and the innermost layer 24. ..

For this reason, the packaging bag 1 having the film configuration (1) has problems in terms of strength and durability. On the other hand, each of the packaging bags 1 having the film configurations (2) and (3) is also effective in terms of strength and durability. In particular, the packaging bag 1 having the film configuration (3) is extremely effective in terms of strength and durability.

<Example 3>
In Example 3, with respect to the packaging bag 1 and the conventional packaging bag according to the present invention, the elution state of polyethylene with respect to the evaluation solvent A and the evaluation solvent B of the laminated sheet 2 (film configurations (1) to (3)) is evaluated. Was done.

(Evaluation target)
The film configurations (1) to (3) having the same configuration as in Example 2 were evaluated.

(Evaluation solvent A)
As the evaluation solvent A, a solvent-based inkjet ink having the same components as in Examples 1 and 2 was prepared.

(Evaluation solvent B)
As the evaluation solvent B, a cleaning solution containing 40% by mass of dipropylene glycol monomethyl ether, an organic solvent such as N, N-dimethylformamide and diethylene glycol diethyl ether, and 60% by mass of a mixture of surfactants was prepared.

(Evaluation methods)
2000 mL of the evaluation solvents A and B were separately filled in each of the packaging bags 1 of the film configurations (1) to (3) and stored at 60 ° C. for 1 week, and then stored at room temperature for 1 day. Then, after storage, 30 mL of the evaluation solvent was extracted from each packaging bag 1 and filtered by its own weight with a 3000 mesh stainless steel filter (opening 5 μm). At this time, the time required for all the evaluation solvents to pass through the filter (filtration time) was measured. If polyethylene elutes when stored at 60 ° C., polyethylene precipitates when stored at room temperature. When polyethylene is deposited, the filtration time becomes long, so the filtration time is an index of the elution state of polyethylene. Therefore, those having a filtration time of a predetermined time (120 seconds) or less were designated as "○ (good)", and those having a filtration time exceeding the predetermined time were designated as "x (poor)".

(Evaluation results)
FIG. 5 shows the evaluation results of each packaging bag 1 of the film configurations (1) to (3) according to this embodiment.

The packaging bag 1 of the film configuration (1) was defective because polyethylene was highly eluted in both the evaluation solvent A (ink solvent) and the evaluation solvent B (cleaning solution). This is because the average melting point of polyethylene contained in the innermost layer 24 of the laminated sheet 2 is 120 ° C., but it is considered that polyethylene having a melting point of 113 ° C. is eluted.

Further, in the packaging bag 1 of the film configuration (2), the elution of polyethylene was good with respect to the evaluation solvent A (ink solvent), but the elution of polyethylene with respect to the evaluation solvent B (cleaning solution) was good. Was relatively occurring and was not good. This is because polyethylene having a melting point of 120 ° C. or higher in the innermost layer 24 does not dissolve in either the evaluation solvent A (ink solvent) or the evaluation solvent B (cleaning solution), while the melting point of the special adhesive layer 25 is less than 120 ° C. This is because polyethylene does not elute in the evaluation solvent A (ink solvent), but elutes in the evaluation solvent B (cleaning solution). Since the evaluation solvent B (cleaning liquid) has a high dissolving power as the ink is washed, the innermost layer 24 is easily swollen by the evaluation solvent B, and as a result, the polyethylene of the special adhesive layer 25 passes through the innermost layer 24. It is considered that the ink is eluted in the evaluation solvent B (cleaning solution). On the other hand, since the evaluation solvent A (ink solvent) does not have high dissolving power, the innermost layer 24 is difficult to swell due to the evaluation solvent A, so that the polyethylene of the special adhesive layer 25 is used as the evaluation solvent A (ink solvent). It is thought that it hardly elutes.

Further, the packaging bag 1 of the film configuration (3) was good because the elution of polyethylene was small with respect to both the evaluation solvent A (ink solvent) and the evaluation solvent B (cleaning solution). This is because both the first innermost layer 241 and the second innermost layer 242 have a melting point of polyethylene of 120 ° C. or higher and a peak melting point of one single polyethylene. In the film configuration (3), since the resin layers other than the innermost layer 24 do not contain polyethylene, polyethylene does not elute from the resin layers other than the innermost layer 24.

For this reason, the packaging bag 1 having the film configuration (1) is difficult to apply to both ink and cleaning liquid. On the other hand, the packaging bag 1 having the film configuration (2) has high strength and durability as in Example 2, and is applicable to ink, but there remains a slight problem in application to the cleaning liquid. It is preferable to use it for the packaging bag 1 that stores ink. Further, since the packaging bag 1 having the film configuration (3) has high strength and durability and is applicable to both ink and cleaning liquid, it is preferable to use the packaging bag 1 for containing ink and cleaning liquid.

Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to those of the illustrated embodiments. Various modifications and modifications can be made to the illustrated embodiments within the same range as the present invention or within the same range.

1 ... Packaging bag 2 ... Laminated sheet 21 ... Base material layer 22 ... Barrier layer 23 ... Intermediate layer 24 ... Innermost layer 25 ... Special adhesive layer

Claims (4)

A packaging bag made by making a laminated sheet in which a plurality of resin layers are laminated and containing ink containing a solvent.
The laminated sheet includes a base material layer laminated on the outside, a barrier layer containing a metal element laminated on the inside of the base material layer, and an intermediate layer containing a polyamide laminated on the inside of the barrier layer. The innermost layer containing polyethylene laminated inside the barrier layer is provided.
The innermost polyethylene is a packaging bag having a melting point of 120 ° C. or higher and 129 ° C. or lower, and having a peak melting point of one single polyethylene. The intermediate layer and the innermost layer are laminated by extruding through a special adhesive layer containing polyethylene having a melting point of less than 120 ° C. in a state where a polyolefin-based adhesive is applied to the surface of the intermediate layer on the innermost layer side. The packaging bag according to claim 1, which is laminated. The innermost layer contains a first innermost layer and a second innermost layer having a melting point of 120 ° C. or higher and 129 ° C. or lower and containing polyethylene having a peak melting point of one single polyethylene, and polyamide. The packaging according to claim 1 or 2, further comprising a third innermost layer, wherein the first innermost layer and the second innermost layer are laminated by coextrusion in a manner of sandwiching the third innermost layer. bag. A laminated sheet in which a plurality of resin layers are laminated, which is used for a packaging bag containing ink containing a solvent.
The base material layer laminated on the outside, the barrier layer containing the metal element laminated on the inside of the base material layer, the intermediate layer containing the polyamide laminated on the inside of the barrier layer, and the barrier layer. With an innermost layer containing polyethylene laminated inside,
The innermost layer of polyethylene is a laminated sheet having a melting point of 120 ° C. or higher and 129 ° C. or lower, and having a peak melting point of one single polyethylene.

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