JPH0811860A - Liquid paper container - Google Patents

Abstract

PURPOSE:To prevent the occurrence of cracking or the leakage of liquid and contrive the improvement of resistance to contents by a method wherein the peripheral wall of a container is formed of a specific laminate sheet containing a paperboard layer as the base material layer and a specific single or laminate layer synthetic resin film is used in a sealing film. CONSTITUTION:In a liquid paper container whose peripheral wall is formed of a laminate sheet 100 containing a paperboard layer 105 as the base material layer and which has a sealing film 200 attached to the inner side of an opening part, as the inner layer farther within the paperboard layer 105 of the laminate sheet 100, a gas-barrier layer 106, a content resisting layer 107 and a sealant layer 102 are formed in that order. In the sealing film 200 is used a single or laminate layer synthetic resin film fusible to the sealant layer 102 and superbly resistant to the contents. In this case, it is preferable that the content resisting layer 107 of the laminate sheet 100 be constituted of a nylon layer or an extrusion formed film containing a nylon layer 208 and that the layer of the sealing film 200 to be kept in contact with the contents be made a linear low-density polyethylene layer 202.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid paper container having a sealing film adhered to the inside of an opening, and more specifically, it has a resistance to contents such that it can contain alkaline contents. It relates to an excellent liquid paper container.

[0002]

2. Description of the Related Art In recent years, liquid paper containers with a gabled roof or a flat top have replaced the conventional glass containers and metal containers with chilled distribution types such as milk, lactic acid bacteria drinks, liquid soups, alcoholic drinks and fruit juice drinks. It is widely used in large quantities for normal temperature distribution type liquid foods that require long-term storage such as soups. More recently, as consumers become more aware of the environment, packages that take into consideration environmental issues have been demanded, and instead of plastic containers, they are also used in non-food fields such as toiletries and liquid detergents. It's starting to happen. Then, in consideration of convenience in use, these liquid paper containers have, for example, a mouth plug (20) at the top opening as shown in FIGS. 8 (a) and (b).
A sealing film (200) which is attached to and seals the opening (11) from the inside by lowering the opening blade (22) at the same time as turning the cap (21) during use. The adhesive film (3) in which the spout (20) and the laminated sheet (100) are heat-sealed and the sealing film (200) is attached.
00) is cut and opened, or as shown in FIGS. 9 (a) and 9 (b), a sheet-like lid material (20) is attached to the top opening, and the lid material (20 ) Is removed, and at the same time, the opening (11) is sealed from the inside by sealing the sealing film (200) by the adhesive force between the lid member (20) and the sealing film (200). And a notch (30) for a vent hole is provided at the top as shown in FIGS. 10 (a) and 10 (b), and is pushed inward at the time of use and adhered and sealed inside. Sealing film (20
Some of them were made by cutting 0) to open a ventilation hole. And, the constitution of the laminated sheet forming the peripheral wall of these liquid paper containers is, for example, in the chilled distribution type, [outside]
Polyethylene layer / paperboard layer (base material layer) / heat-fusible polyethylene layer (sealant layer) [inside] structure is used, and in complicated ones, [outer] polyethylene layer / paperboard layer (base material layer) / heat fusion Adhesive polyethylene layer (sealant layer) [inside] configuration is used, and in the normal temperature distribution type, [outside] polyethylene layer / paperboard layer (base material layer) / polyethylene layer / aluminum foil layer / polyethylene terephthalate layer / heat-bonding property Polyethylene layer (sealant layer) [inside] configuration,
[Outside] A polyethylene layer / paperboard layer (base material layer) / polyethylene layer / polyethylene terephthalate layer / heat-fusible polyethylene layer (sealant layer) [inside] configuration was used. In addition, a polyethylene film having a good heat fusion property is generally used as the sealing film attached to the inside of the opening.

[0003]

However, the above-mentioned liquid paper container for liquids for food of the chilled distribution type or the normal temperature distribution type is provided with non-food contents such as alkaline contents such as car wash detergent and kitchen detergent. When used by filling, the innermost layer of the heat-fusible polyethylene layer of the laminated sheet that forms the peripheral wall of the container, such as the folding part at the top of the liquid paper container, the end of the heat-sealing part, and the heat-fusion folding part at the bottom. A crack due to stress cracking occurs over time in the (sealant layer) where internal stress is applied, and the alkaline solution of the contents penetrates from this crack and reaches the aluminum foil layer or polyethylene terephthalate layer, which is the intermediate barrier layer. Corroded the aluminum foil layer or hydrolyzed and dissolved the polyethylene terephthalate layer, or was stuck inside the opening And crack the sealing film of Riechiren, contents had to be liquid leaking from the liquid cartons.

The present invention improves the above-mentioned problems that occur when a conventional liquid paper container is filled with a non-food such as alkaline contents, and provides a liquid paper container having excellent resistance to contents. Is.

[0005]

A first aspect of the present invention is a liquid paper container in which a peripheral wall is formed by a laminated sheet having a paperboard layer as a base material layer, and a sealing film is attached to the inside of the opening, wherein the laminated sheet is used. The inner layer from the paper layer of the sheet is composed of a gas barrier layer, a content-resistant layer, and a sealant layer in this order, and the sealing film has heat-sealing properties with the sealant layer and is excellent for the content. A liquid paper container characterized by being a single-layer or laminated synthetic resin film having resistance to contents.

A second invention is a liquid paper container, wherein the content resistant layer of the laminated sheet according to the first invention is a nylon layer.

A third invention is a liquid paper container characterized in that the content resistant layer of the laminated sheet according to the first invention is an extruded film containing a nylon layer.

A fourth invention is a liquid paper container characterized in that the layer in contact with the contents of the sealing film according to the first invention is a linear low density polyethylene layer.

The above-mentioned laminated sheet is obtained by laminating a plastic film or an aluminum foil with a substrate layer as a paperboard by dry laminating by a processing method, an extrusion laminating method, a wet laminating method or the like.

The sealant layer is a layer formed of a polyethylene resin which is easily heat-sealed by a gas frame, hot air, a hot plate or the like during the box making process.

[0011]

In the liquid paper container of the present invention, for example, when the content is an alkaline solution, even if a crack is generated in the innermost sealant layer due to stress cracking, the alkaline solution that has penetrated from the crack is Invasion is prevented by an alkali-resistant content-resistant layer provided between the barrier layer and the innermost sealant layer, and it is extremely rare to reach the intermediate barrier layer such as an aluminum foil layer or a polyethylene terephthalate layer. . In addition, the sealing film attached to the inside of the opening has a good heat fusion property with the innermost sealant layer of the liquid paper container, and is a single-layer or laminated composite having excellent content resistance to the content. Since a resin film is used, it is extremely unlikely to cause cracking or peeling with time depending on the content.

[0012]

【Example】

<Example 1> First, by using the extrusion laminating method and the dry laminating method, the [outer] low density polyethylene layer (101) (25 μm) shown in FIG.
) / Paperboard (105) (350 g / m ² , substrate layer) / Low-density polyethylene layer (101) (25 μm) / Aluminum foil layer (106) (7 μm, barrier layer) / Stretched nylon layer (107) (15 μm) , Content resistant layer) / linear low-density polyethylene layer (102) (25 μm) / high-density polyethylene layer (104) (25 μm) / linear low-density polyethylene layer (102) (60 μm, sealant layer) [inside] A laminated sheet (100) of was prepared. Separately from this, a dry lamination method is used to form the [outer] linear low-density polyethylene layers (202) (20) shown in FIG.
μm) / non-stretched nylon layer (208) (15 μm) / linear low-density polyethylene layer (202) (20 μm) [inside] A sealing film (200) having a constitution was prepared and cut into a predetermined shape and size. .

Next, the above-mentioned laminated sheet is punched by a punching machine to produce a blank having an opening at the top, and a sealing film made separately is attached to the inner surface of the opening of the blank to seal the blank. , This blank is side-sealed to make a back-coated sleeve, and this sleeve is loaded into the filling machine,
The bottom part is heat-sealed and sealed, filled with a car wash detergent, and the top part is heat-sealed and sealed to seal the inner volume to 2,
A 000 ml liquid paper container of this example was prepared.

Then, in order to evaluate the content resistance of the produced liquid paper container of this embodiment, the liquid paper container was stored for 3 months in a thermo-hygrostat at 40 ° C. and 90% RH to check the state of liquid leakage from the container. I observed. Table 1 shows the results.

Example 2 First, by using the extrusion laminating method and the dry laminating method, the [outer] low density polyethylene layer (10) shown in FIG.
1) (25 μm) / paperboard (105) (350 g / m ² , substrate layer) / low density polyethylene layer (101) (25 μm)
/ Aluminum foil layer (106) (7μm, barrier layer) /
Stretched nylon layer (107) (15 μm, content resistant layer) /
Linear low-density polyethylene layer (102) (25 μm) / non-stretched nylon layer (108) (15 μm, content resistant layer) /
A laminated sheet (100) having a linear low-density polyethylene layer (102) (60 μm, sealant layer) [inside] was prepared. The inner linear low density polyethylene layer (10
The 2) / unstretched nylon layer (108) / linear low density polyethylene layer (102) construction is a coextruded film.
Next, separately from the laminated sheet (100), an extrusion laminating method is used to form the [outer] linear low-density polyethylene layer (202) (20 μm) shown in FIG. 2 (b).
m) / High-density polyethylene layer (208) (20 μm) /
A sealing film (200) having a linear low-density polyethylene layer (202) (20 μm) [inside] was prepared and cut into a predetermined shape and size.

Next, in the same manner as in Example 1, the above-mentioned laminated sheet was punched by a punching machine to prepare a blank having an opening at the top, and a sealing film separately prepared on the inner surface side of the opening of this blank. After sticking and sealing, this blank was side-sealed to make a back-coated sleeve, this sleeve was loaded into a filling machine, the bottom was heat-sealed and sealed, and after filling with a car wash detergent. The top was heat-sealed, sealed and hermetically sealed to prepare a liquid paper container of this example having an inner volume of 2,000 ml.

Then, in the same manner as in Example 1, in order to evaluate the content resistance of the produced liquid paper container of this Example, 40
It was stored in a thermo-hygrostat at 90 ° C and 90% RH for 3 months, and the state of liquid leakage from the container was observed. Table 1 shows the results.

Example 3 First, by using the extrusion laminating method and the dry laminating method, the [outside] low density polyethylene layer (10) shown in FIG.
1) (25 μm) / paperboard (105) (350 g / m ² , substrate layer) / low density polyethylene layer (101) (25 μm)
/ Aluminum foil layer (106) (7μm, barrier layer) /
Stretched nylon layer (107) (15 μm, content resistant layer) /
Low-density polyethylene layer (101) (25 μm) / non-stretched nylon layer (108) (15 μm, content resistant layer) / low-density polyethylene layer (101) (60 μm, sealant layer) [inside] laminated sheet (100) Was produced.
The inner low-density polyethylene layer (101) / non-stretched nylon layer (108) / low-density polyethylene layer (10)
1) The structure is an extruded film. Next, separately from the laminated sheet, using the extrusion lamination method, the [outer] linear low-density polyethylene layer (202) (20 μm) / high-density polyethylene layer (204) (shown in FIG. 3B). 20 μm) / low density polyethylene layer (20
1) (20 μm) [inside] sealing film (20
0) was prepared and cut into a predetermined shape and size.

Next, in the same manner as in Example 1, the above-mentioned laminated sheet was punched by a punching machine to prepare a blank having an opening at the top, and a sealing film separately prepared on the inner surface side of the opening of this blank. After sticking and sealing, this blank was side-sealed to make a back-coated sleeve, this sleeve was loaded into a filling machine, the bottom was heat-sealed and sealed, and after filling with a car wash detergent. The top was heat-sealed, sealed and hermetically sealed to prepare a liquid paper container of this example having an inner volume of 2,000 ml.

Then, in the same manner as in Example 1, in order to evaluate the content resistance of the produced liquid paper container of this Example, 40
It was stored in a thermo-hygrostat at 90 ° C and 90% RH for 3 months, and the state of liquid leakage from the container was observed. Table 1 shows the results.

Example 4 First, by using the extrusion laminating method and the dry laminating method, the [outer] low density polyethylene layer (10) shown in FIG.
1) (25 μm) / paperboard (105) (350 g / m ² , substrate layer) / low density polyethylene layer (101) (25 μm)
/ Aluminum foil layer (106) (7μm, barrier layer) /
Stretched nylon layer (107) (15 μm, content resistant layer) /
A laminated sheet (100) having a linear low-density polyethylene layer (102) (60 μm, sealant layer) [inside] was prepared. Separately from this, using the extrusion laminating method, the [outer] linear low density polyethylene layer (202) (20 μm) / medium density polyethylene layer (203) (20 μm) / low shown in FIG. A sealing film (200) having a density polyethylene layer (201) (20 μm) [inside] was prepared and cut into a predetermined shape and size.

Next, in the same manner as in Example 1, the above-mentioned laminated sheet was punched by a punching machine to produce a blank having an opening at the top, and a sealing film produced separately on the inner surface side of the opening of this blank was used. After sticking and sealing, this blank was side-sealed to make a back-coated sleeve, this sleeve was loaded into a filling machine, the bottom was heat-sealed and sealed, and after filling with a car wash detergent. The top was heat-sealed, sealed and hermetically sealed to prepare a liquid paper container of this example having an inner volume of 2,000 ml.

Then, in the same manner as in Example 1, in order to evaluate the content resistance of the produced liquid paper container of this Example, 40
It was stored in a thermo-hygrostat at 90 ° C and 90% RH for 3 months, and the state of liquid leakage from the container was observed. Table 1 shows the results.

<Example 5> First, by using the extrusion laminating method and the dry laminating method, the [outside] low density polyethylene layer (10) shown in FIG.
1) (25 μm) / paperboard (105) (350 g / m ² , substrate layer) / low density polyethylene layer (101) (25 μm)
/ Aluminum foil layer (106) (7μm, barrier layer) /
Stretched nylon layer (107) (15 μm, content resistant layer) /
A laminated sheet (100) having a medium density polyethylene layer (103) (60 μm, sealant layer) [inside] was prepared. Separately from this, a linear low-density polyethylene film having a thickness of 60 μm was cut into a predetermined shape and size,
Single layer (202) sealing film (200) shown in (b)
Was produced.

Then, in the same manner as in Example 1, the above-mentioned laminated sheet was punched by a punching machine to produce a blank having an opening at the top, and a sealing film separately produced on the inner surface side of the opening of this blank was used. After sticking and sealing, this blank was side-sealed to make a back-coated sleeve, this sleeve was loaded into a filling machine, the bottom was heat-sealed and sealed, and after filling with a car wash detergent. The top was heat-sealed, sealed and hermetically sealed to prepare a liquid paper container of this example having an inner volume of 2,000 ml.

Then, in the same manner as in Example 1, in order to evaluate the content resistance of the liquid paper container of this example produced, 40
It was stored in a thermo-hygrostat at 90 ° C and 90% RH for 3 months, and the state of liquid leakage from the container was observed. Table 1 shows the results.

<Comparative Example 1> Further, in order to compare the contents resistance with the liquid paper containers of the above-mentioned five examples of the present invention, a conventional liquid paper container was prepared. First, using the extrusion laminating method and the dry laminating method, the [outer] low density polyethylene layer (101) (25 μm) / paperboard (105) (3) shown in FIG.
50 g / m ² , substrate layer) / low-density polyethylene layer (10
1) (25 μm) / aluminum foil layer (106) (7 μm
m, barrier layer) / polyethylene terephthalate layer (10
9) (12 μm, content resistant layer) / low density polyethylene layer (101) (60 μm, sealant layer) [inside] A laminated sheet (100) having a constitution was produced. Separately from this, by the extrusion molding method, 60 shown in FIG.
A sealing film (200) of a low-density polyethylene single layer (201) having a thickness of μm was produced and cut into a predetermined shape and size.

Next, in the same manner as in Example 1, the above-mentioned laminated sheet was punched by a punching machine to produce a blank having an opening at the top, and a sealing film separately produced on the inner surface side of the opening of this blank. After sticking and sealing, this blank was side-sealed to make a back-coated sleeve, this sleeve was loaded into a filling machine, the bottom was heat-sealed and sealed, and after filling with a car wash detergent. The top was heat-sealed, sealed and hermetically sealed to prepare a liquid paper container of this example having an inner volume of 2,000 ml.

Then, in the same manner as in Example 1, in order to evaluate the content resistance of the produced liquid paper container of this Example, 40
It was stored in a thermo-hygrostat at 90 ° C and 90% RH for 3 months, and the state of liquid leakage from the container was observed. Table 1 shows the results.

<Comparative Example 2> A liquid paper container of another conventional example was also prepared at the same time. First, using the extrusion laminating method and the dry laminating method,
[Outside] low density polyethylene layer (10
1) (25 μm) / paperboard (105) (350 g / m ² , substrate layer) / low density polyethylene layer (101) (25 μm)
/ Low-density polyethylene layer (101) (25 µm) / Polyethylene terephthalate layer (109) (12 µm, barrier layer and content resistant layer) / Low-density polyethylene layer (10
1) A laminated sheet (100) having a (60 μm, sealant layer) [inside] structure was produced. Separately from this, a sealing film (200) of a low-density polyethylene single layer (201) having a thickness of 60 μm shown in FIG. 6 (b) was produced by an extrusion molding method, and cut into a predetermined shape and size. .

Next, in the same manner as in Example 1, the above-mentioned laminated sheet was punched by a punching machine to produce a blank having an opening at the top, and a sealing film separately produced on the inner surface side of the opening of this blank. After sticking and sealing, this blank was side-sealed to make a back-coated sleeve, this sleeve was loaded into a filling machine, the bottom was heat-sealed and sealed, and after filling with a car wash detergent. The top was heat-sealed, sealed and hermetically sealed to prepare a liquid paper container of this example having an inner volume of 2,000 ml.

Then, in the same manner as in Example 1, in order to evaluate the content resistance of the produced liquid paper container of this Example, 40
It was stored in a thermo-hygrostat at 90 ° C and 90% RH for 3 months, and the state of liquid leakage from the container was observed. Table 1 shows the results.

[0033]

[Table 1]

As shown in Table 1, in Comparative Examples 1 and 2 which are conventional liquid paper containers, liquid leakage occurred at the top or bottom of all containers within 2 months. Regarding Example 1, Example 2, Example 3, Example 4, and Example 5, no liquid leakage was observed in any of the containers during 3 months.

[0035]

When the liquid paper container of the present invention is used, for example, even if a non-food item such as an alkaline content is filled as the content, the innermost sealant layer and the intermediate layer of the laminated sheet forming the peripheral wall of the container are used. Since an alkali-resistant content-resistant layer such as a nylon layer is provided between the barrier layer and the barrier layer, the innermost sealant layer undergoes stress cracking due to content during storage, distribution and use, and cracks. Even if it is possible, there is very little liquid leakage. In addition, the sealing film attached to the inside of the opening has a good heat fusion property with the innermost sealant layer of the liquid paper container, and is a single-layer or laminated composite having excellent content resistance to the content. Since a resin film is used, it is extremely unlikely to cause cracking or peeling with time depending on the content.

[Brief description of drawings]

FIG. 1A is a sectional view showing a structure of a laminated sheet forming a peripheral wall of a liquid paper container of Example 1, and FIG.
FIG. 4 is a cross-sectional view showing a configuration of a sealing film attached to the inside of an opening of a paper container.

FIG. 2A is a sectional view showing a structure of a laminated sheet forming a peripheral wall of a liquid paper container of Example 2, and FIG.
FIG. 4 is a cross-sectional view showing a configuration of a sealing film attached to the inside of an opening of a paper container.

FIG. 3A is a sectional view showing a configuration of a laminated sheet forming a peripheral wall of a liquid paper container of Example 3, and FIG.
FIG. 4 is a cross-sectional view showing a configuration of a sealing film attached to the inside of an opening of a paper container.

FIG. 4A is a sectional view showing a structure of a laminated sheet forming a peripheral wall of a liquid paper container of Example 4, and FIG.
FIG. 4 is a cross-sectional view showing a configuration of a sealing film attached to the inside of an opening of a paper container.

5A is a cross-sectional view showing the structure of a laminated sheet forming the peripheral wall of the liquid paper container of Example 5, and FIG.
FIG. 4 is a cross-sectional view showing a configuration of a sealing film attached to the inside of an opening of a paper container.

6A is a cross-sectional view showing the structure of a laminated sheet forming the peripheral wall of the liquid paper container of Comparative Example 1, and FIG.
FIG. 4 is a cross-sectional view showing a configuration of a sealing film attached to the inside of an opening of a paper container.

7A is a cross-sectional view showing the configuration of a laminated sheet forming the peripheral wall of the liquid paper container of Comparative Example 2, and FIG.
FIG. 4 is a cross-sectional view showing a configuration of a sealing film attached to the inside of an opening of a paper container.

FIG. 8A is a partial perspective view of a liquid paper container in which a mouth plug is attached to the top opening, and FIG. 8B is a partial cross-sectional view showing a state of the mouth stopper attachment portion.

FIG. 9 (a) is a partial perspective view of a liquid paper container having an opening sheet attached to the top opening, and FIG. 9 (b) is a partial cross-sectional view showing the state of the opening sheet attached portion. is there.

FIG. 10A is a partial perspective view of a liquid paper container having an air hole at the top, and FIG. 10B is a partial cross-sectional view showing the state of the portion having the air hole.

[Explanation of symbols]

 10 ... Liquid paper container 11 ... Opening part 20 ... Mouth plug 21 ... Cap 22 ... Opening blade 30 ... Air hole notch 100 ... Laminated sheet 101, 201 ... Low density polyethylene layer or single layer 102 , 202 ... Linear low-density polyethylene layer or single layer 103, 203 ... Medium-density polyethylene layer 104, 204 ... High-density polyethylene layer 105 ... Paperboard layer 106 ... Aluminum foil layer 107 ... Stretched nylon layer 108, 208: unstretched nylon layer 109: polyethylene terephthalate layer 200: sealing film 300: adhesive film

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location B65D 5/56 A (72) Inventor Shigenori Morishima 1-5-1 Taito, Taito-ku, Tokyo Toppan stamp Printing Co., Ltd. (72) Inventor Toshiya Naito 1-5-1 Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd.

Claims (4)

[Claims] 1. A liquid paper container in which a peripheral wall is formed of a laminated sheet having a paperboard layer as a base material layer, and a sealing film is adhered to the inside of an opening, wherein the inner layer of the laminated sheet is a paper layer.
A gas barrier layer, a content resistant layer, a sealant layer in this order, and, the sealing film has a heat fusion property with the sealant layer, a single layer having excellent content resistance to the content or A liquid paper container, which is a laminated synthetic resin film. 2. A liquid paper container, wherein the content-resistant layer of the laminated sheet according to claim 1 is a nylon layer. 3. A liquid paper container, wherein the content-resistant layer of the laminated sheet according to claim 1 is an extruded film containing a nylon layer. 4. A liquid paper container, wherein the layer in contact with the content of the sealing film according to claim 1 is a linear low density polyethylene layer.