JP2001270516A - Paper container with hot water resistance - Google Patents

Abstract

(57) [Summary] [PROBLEMS] Compared with conventional water-resistant paper, the strength in a moisture-absorbed state with hot water can be greatly improved. Provided is a paper container which can be cooked and has extremely excellent hot water resistance. A paper whose dimensional change in a paper wet state under a wet condition of immersion in hot water of 90 ° C. or more for 1 hour is 4% or less is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper container which requires hot water and contains contents which need to be sterilized and cooked by hot water treatment of, for example, beverages and foodstuffs. By using paper having extremely excellent hot water properties in a container using paper having the same, it is possible to improve the hot water resistance and strength of the paper container, and to perform cooking by boiling sterilization, retort sterilization, and hot water treatment. And a paper container having hot water resistance.

[0002]

2. Description of the Related Art In recent years, environmental problems have become serious and containers and packaging materials have to be easily disposed of, and demand for easy incineration, recyclability, or use of recycled materials has been increasing.

[0003] Therefore, the outside of the plastic container is
2. Description of the Related Art Paper having hot water resistance coated with a fiber structure such as paper has been proposed.

[0004] Further, various containers have been proposed using paper having hot water resistance in which the amount of plastic used is greatly reduced, and paper having high heat water resistance which can be separated from paper and plastic at the time of disposal.

[0005] In a paper container made of plastic and paper having a hot water resistance, the amount of plastic used in the inner container is reduced as much as possible in order to cope with environmental problems and resource saving. Therefore, the strength physical properties of the interior plastic container itself as a container are greatly reduced.

[0006] Therefore, by combining a paper outer container with a plastic inner container, the strength physical properties of the container itself are ensured.

However, the conventional hot water resistance of an external paper container made of paper having hot water resistance, particularly when water is absorbed from the end face of a paper member, the strength of the paper base material is remarkably reduced. Was hard to say.

[0008]

Therefore, in order to provide hot water resistance, it is necessary to secure the wet strength without significantly reducing the amount of resin used in the inner plastic container, or to use an external paper container made of a plastic film. In some cases, the wet strength is maintained by preventing the intrusion of water by coating with water.

Further, these conventional paper containers having heat and water resistance have water resistance and content resistance in preserving the contents, but have a degree of resistance to use in kitchens, washstands, and bathrooms. Is insufficient in hot water resistance and has problems such as delamination of paper.

Further, many containers for storing foods and beverages require sterilization treatment with hot water and heating cooking, and cannot be used as containers.

The present invention has been made in view of the above-mentioned problems, and can greatly improve the strength in a state of absorbing moisture with hot water as compared with conventional paper having hot water resistance. It is an object of the present invention to provide a paper container having extremely excellent hot water resistance, which can be cooked by boiling sterilization, retort sterilization, and hot water treatment.

[0012]

Means for Solving the Problems The present invention has been made as a result of intensive studies to achieve the above object, and the invention corresponding to claim 1 is immersed in hot water of 90 ° C. or more for one hour. A paper container having hot water resistance, characterized by using paper whose dimensional change in a paper wet state under wet conditions of 4% or less.

The invention corresponding to claim 2 uses a paper having a ring crush strength (JIS P8126) of 0.9 N or more in a wet state of paper under a wet condition of immersion in hot water of 90 ° C. or more for 1 hour. It is a paper container having hot water resistance.

According to a third aspect of the present invention, a paper having a bending yield strength of 0.6 N / 40 mm or more in a paper wet state under a wet condition of immersion in hot water of 90 ° C. or more for one hour is used. This is a paper container having hot water resistance.

According to a fourth aspect of the present invention, the folding yield strength in the wet state of the paper / the folding yield strength in the dry state of 10% is immersed in hot water of 90 ° C. or more for one hour.
A paper container having hot water resistance, characterized by using the paper described above.

According to a fifth aspect of the present invention, there is provided a paper container main body having the hot water resistance according to the first aspect, wherein the paper container main body is immersed in hot water of 90 ° C. or more for 1 hour in a wet state of paper. A paper container having hot water resistance, characterized by using paper having a tensile strength at break of 30 N / 15 mm or more.

According to a sixth aspect of the present invention, the paper container body having the hot water resistance according to the first aspect is characterized in that the paper container body is immersed in hot water of 90 ° C. or more for one hour under a wet condition of paper. A paper container having hot water resistance, characterized by using paper having a tensile strength at break / tensile strength in dry state of 10% or more.

The invention corresponding to claim 7 is characterized in that a paper having a tensile elongation at break of 10% or more in a wet state of the paper under a wet condition of immersion in hot water of 90 ° C. or more for 1 hour is used. It is a paper container having hot water resistance.

According to an eighth aspect of the present invention, there is provided a paper container body having hot water resistance according to any one of the second to seventh aspects, wherein the paper container body is immersed in hot water of 90 ° C. or more for one hour. A paper container having a hot water resistance, characterized by using a paper having a surface water absorption (JIS P8140 Cobb method) of 100 g / m ² or less in a paper wet state below.

According to a ninth aspect of the present invention, there is provided a paper container body having hot water resistance according to any one of the second to seventh aspects, wherein the entire water absorption of hot water of 90 ° C. or more is made of paper. Wherein the weight ratio of the paper is 80% or less.

According to a tenth aspect of the present invention, there is provided a paper container obtained by impregnating and coating a resin container body having hot water resistance according to any one of the first to ninth aspects. It is a paper container consisting of

According to an eleventh aspect of the present invention, the paper container body having hot water resistance according to any one of the first to tenth aspects is provided with a thermoplastic resin layer at least inside. It is a paper container having hot water resistance.

According to a twelfth aspect of the present invention, the paper container body having hot water resistance according to any one of the first to eleventh aspects has a shape having an upper opening. This is a paper container having hot water resistance.

According to a thirteenth aspect of the present invention, there is provided a paper container body having hot water resistance according to any one of the first to eleventh aspects, wherein the main body has a cylindrical shape having at least a top portion, a body portion, and a bottom portion. It is a paper container having hot water resistance.

According to a fourteenth aspect of the present invention, there is provided a paper container main body having hot water resistance according to any one of the first to eleventh aspects, wherein the main body comprises a tetrahedron having at least a top part, a body part and a bottom part; It is a paper container having a hot water resistance, which is a hexahedron or a roof shape.

According to a fifteenth aspect of the present invention, the paper container body having the hot water resistance according to any one of the first to eleventh aspects has a bag-like shape. This is a paper container having:

According to a sixteenth aspect of the present invention, the paper container body having the hot water resistance according to any one of the first to eleventh aspects has a hot water resistance characterized in that the main body has a bottle shape. It is a paper container.

[0028]

Embodiments of the present invention will be described below in detail with reference to the drawings.

The paper according to the present invention is used for a member of a paper container having a hot water resistance. In order for the container to maintain its strength in a wet state, the paper constituting the container must absorb water. Strength is not lost.

That is, if the paper has low water absorption and the dimensional change and strength of the paper after water absorption are in the following ranges, it is possible to obtain a paper container having hot water resistance that does not cause breakage or the like.

In addition, a paper container is filled with contents at a high temperature,
In performing high-temperature hot water treatment such as boil treatment and retort treatment on the container after filling the contents, the performance required to maintain the performance of the paper container is measured using hot water of 90 ° C. or more. In terms of value, the dimensional change in the paper wet condition under the wet condition of immersion in hot water of 90 ° C. or more for 1 hour is 4% or less, and the paper wet condition under the wet condition of immersion in the hot water of 90 ° C. or more for 1 hour. Crush strength (JIS P8126) at 0.9N or more, 90
The paper has a bending yield strength of 0.6 N / 40 mm or more and 90 N or more in a wet state of paper immersed in hot water of 1 ° C. or more for 1 hour.
Folding yield strength in wet condition of paper / humid condition of 1 hour immersion in hot water of 1 ° C or higher / Bending yield strength in dry condition of 10% or more, wet condition of 1 hour immersion in hot water of 90 ° C or higher Breaking strength in wet condition of paper at 30 N / 15
Tensile strength at break in wet state of paper / dry tensile strength at 10% or more under hot condition of immersion in hot water at 90 ° C or more for 1 hour Tensile elongation at break in wet condition of paper under wet condition of immersion is 10
%, The surface water absorption (JIS P8140 Cobb method) under the wet condition of immersion in hot water of 90 ° C. or more for 1 hour is 100 g / m ² or less, and the total water absorption of hot water at 90 ° C. or more is 100% / m ² or less. ,
It is sufficient that the weight ratio with respect to paper is 80% or less, or an appropriate combination thereof.

Here, as the paper having the hot water resistance, paper and impregnated paper can be used.

The types of paper include those made of 100% virgin pulp, those made of 100% recycled waste paper, those mixed at an arbitrary ratio, NBKP material, LBKP
Use of various types of paper, such as wood fiber pulp, vegetable fiber materials other than wood pulp, such as kenaf, baccarat, and bamboo, synthetic resin pulp, and clay-coated paper, in the form of containers, contents, and desired water resistance It can be used depending on the level.

Further, these can be used as processed base paper, and can be used as processed paper for impregnating and coating with a paper strength enhancer, a waterproofing agent and a water repellent when wet.

These paper base materials may be impregnated with a resin capable of imparting rigidity, hot water resistance, and hot water resistance as a secondary process at or after the paper making.

The paper here includes non-woven fabric, cloth and the like, and is not limited to a so-called paper type by papermaking.

These paper base materials are impregnated with a resin capable of imparting hot water resistance and hot water resistance as a secondary process after or at the paper making stage.

The method of impregnation and coating with this external additive includes:
There are a dipping method in which the fibrous structure is immersed in the impregnating agent and an excessive amount of the impregnating agent is temporarily applied, and a gravure coating method or a roll coating method in which the impregnating agent is preferably applied or impregnated in a fixed amount. It is also possible to impregnate the impregnating material from the front and back of the fiber structure.

Further, in the gravure impregnation method having two or more units, first, an impregnating material to be impregnated inside the paper base material is applied from one side or both sides, and the impregnating material penetrates into the base material. In the last unit after that, it becomes possible to form a coating film layer on the surface of the paper substrate.

The impregnated paper thus obtained has a high wet strength by impregnating a wet paper strength enhancer or the like over the entire interior of the impregnated paper, for example. Can have a water-repellent effect.

That is, as long as the method can supply the impregnating material to the paper substrate, it depends on the type of the paper substrate and the impregnating material to be used. Can be.

Further, since these processes are performed in a secondary process, a small amount of processing can be performed at a lower cost as compared with the papermaking process.

In order to obtain a paper having hot water resistance, a resin added to a paper base material at the time of impregnation, coating, and paper making. As another thing, a polyvinyl alcohol resin may be used to provide dry strength, hot water resistance and wet strength. , Polyacrylamide, starch, etc., and as a wet strength agent,
Urea formaldehyde resin, melamine formaldehyde resin, starch, polyamidoamine, epichlorohydrin modified product thereof, and various latexes such as natural rubber latex, SBR, NBR, synthetic rubber latex such as polychloroprene, polyvinyl acetate, acrylic resin,
Polyvinyl chloride, polyvinylidene chloride, or a resin latex of a copolymer thereof is used.

Examples of the resin capable of imparting hot water resistance include thermosetting resins such as silane resins, melamine resins, urethane resins and isocyanate resins, as well as acrylic resins, polyester resins, polyethylene resins and polypropylene resins. And the like can also be selected and used depending on the required temperature of hot water.

Even when high water repellency or the like is required as an additional function, the above resin materials may be combined or mixed according to the required function level as long as the required hot water resistance is not impaired. It is also possible to use paper having a resin layer, such as one side of paper, or both sides of paper, paper / resin layer / paper, and a polyolefin such as polyethylene resin or polypropylene resin outside the container. In addition to the base resin, a barrier resin layer such as a polyester resin, a polyamide resin or an ethylene-vinyl alcohol copolymer, or a simple substance of a perforated product thereof, a resin obtained by vapor-depositing an inorganic substance represented by Al, AlOx, and SiOx. Films or composite films combining these also impart appearance, oxygen barrier properties, water vapor barrier properties and fragrance retention Can be used for purpose.

That is, in the present invention, the paper having the hot water resistance and the container using the same are not limited to the lamination structure, but the delamination strength with the paper having the hot water resistance is 0.79N. / 15 mm or more.

In the present invention, the shape of the container made of water-resistant paper has a typical shape, for example, as shown in the perspective views of FIGS. Shape, cup shape with body and bottom, tray shape, top, cylindrical shape with body and bottom, top, tetrahedron with body and bottom, hexahedron, or roof shape,
There is a so-called milk pack shape, a bag shape, a bottle shape, and a so-called trihedral shape so-called triangular milk shape having a torso and a bottom, a mountain-shaped top, and any of these shapes can be selected. The shape may be as follows.

The method of molding a container using paper having hot water resistance may be a known method depending on the shape of the container.

The strength of the paper used as a food container and member made of the paper having hot water resistance of the present invention satisfies the drop test method specified for each weight of the container containing the contents specified in the Food Sanitation Law. Need to be

According to the above-described embodiment of the present invention, the value measured using hot water of 90 ° C. or higher is a value obtained by immersing the paper in hot water of 90 ° C. or higher for 1 hour under a paper wet condition. Crushing strength of paper under wet condition of immersion in hot water of 90 ° C or more for 1 hour with dimensional change of JIS 4% or less (JIS)
P8126) is immersed in hot water of 0.9 N or more and 90 ° C. or more for 90 minutes or more at 90 ° C. or more. Yield strength in wet condition of paper under wet condition
The paper has a tensile yield strength of 10% or more in the dry state and a tensile strength at break of 30 N / 15 mm or more in hot water of 90 ° C. or more under the wet condition of immersion in hot water of 90 ° C. or more for 1 hour. Tensile strength at break in wet state of paper / dry strength under wet condition of 1 hour immersion of 10% or more,
The paper has a tensile elongation at break of 10% or more in a wet condition of paper immersed in hot water of 90 ° C. or more for 1 hour and a wet condition of paper immersed in hot water of 90 ° C. or more for 1 hour. Has a surface water absorption (JIS P8140 Cobb method) of 100 g / m ² or less, 9
By using paper for a container having a total water absorption of 0 ° C. or more of 80% or less by weight with paper or a suitable combination of these, a paper container having good hot water resistance can be obtained. It becomes possible.

That is, by using paper for a container having a dimensional change of 4% or less in a wet state of the paper under a humid condition of immersion in hot water of 90 ° C. or more for 1 hour, the appearance of the paper is not impaired. It becomes possible to obtain a container.

Further, the ring crush strength (JI) in a paper wet state under a humid condition of immersion in hot water of 90 ° C. or more for one hour.
By using paper for a container having SP8126) of 0.9 N or more, it is possible to obtain a paper container that is strong even when it absorbs water.

Furthermore, the fold yield strength of the paper in a wet state under a wet condition of immersion in hot water of 90 ° C. or higher for 1 hour is 0.1%.
By using paper for containers of 6N / 40mm or more,
It becomes possible to obtain a paper container which is strong even if it absorbs water.

Further, the bending yield strength in the paper wet state under the humid condition of immersion in hot water of 90 ° C. or more for 1 hour /
By using paper for a container having a bending yield strength of 10% or more in a dry state, it is possible to obtain a paper container that is strong even when absorbing water.

On the other hand, the paper has a tensile breaking strength of 30 N /
By using paper for a container of 15 mm or more, it is possible to obtain a paper container that is strong even when it absorbs water.

Further, a paper for a container having a tensile strength at break of 10% or more in the wet state of the paper / tensile strength in the dry state of 10% or more under wet conditions of immersion in hot water of 90 ° C. or more for 1 hour. Thereby, it is possible to obtain a paper container that is strong even if it absorbs water.

Further, the tensile elongation at break in the wet state of the paper under the humid condition of immersion in hot water of 90 ° C. or more for 1 hour is 10%.
By using the container paper described above, it is possible to obtain a paper container that is strong even if it absorbs water.

Further, by using paper for a container having a surface water absorption (JIS P8140 Cobb method) of 100 g / m ² or less in a wet state of paper under a humid condition of immersion in hot water of 90 ° C. or more for 1 hour. Since it does not absorb water, it is possible to obtain a paper container that does not decrease in strength.

Further, the total absorption of hot water of 90 ° C. or more
By using paper for a container having a weight ratio of 80% or less with respect to paper, water is not absorbed, so that a paper container that does not decrease in strength can be obtained.

[0060]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below.

(Example 1) As a paper base material for a container, a basis weight of 3
Using a coated ball base paper of 10 g / m ² , an isocyanate resin containing isophorone diisocyanate as a main component was impregnated by a dipping method to obtain an impregnated paper. The content is 7.5 g / m ² . The impregnated paper was further printed, and a polyethylene resin was extruded on the content-filled surface and laminated by lamination.

This is punched out so as to have a developed shape of a hexahedral container having a top portion, a body portion and a bottom portion and having a full capacity of 300 ml and having a full capacity of 300 ml. After filling the food with fluidity, sealing the filling port and heating the obtained container with hot water of 90 ° C. for 1 hour,
The mixture was cooled with room temperature water at 20 ° C. for 1 hour.

The container was sufficiently resistant to hot water sterilization, and no breakage or peeling of the paper / resin layer occurred.

(Example 2) As a paper base material for a container, a basis weight of 30
Using an uncoated cup base paper of 0 g / m ² , an isocyanate resin was impregnated by a dipping method to obtain an impregnated paper. The content is 5.0 g / m ² . The impregnated paper was further printed.

This is punched out into a container having a tray shape with a full capacity of 300 ml, formed into a tray shape, inserted into a mold of a vacuum sheet forming machine, and adhered to the inner surface of the formed tray. Vacuum molding was performed on a sheet of a polypropylene / EVOH / polypropylene structure coated with the agent, and at the same time, the sheet was made to follow the inner surface of the tray. The obtained container was filled with a food having fluidity, and a lid made of polypropylene / EVOH / polypropylene was sealed. After that, the obtained container was subjected to a retort treatment at 120 ° C. for 30 minutes.

The container was sufficiently resistant to hot water sterilization, and did not cause breakage or peeling of the paper / resin layer.

The paper having hot water resistance was sufficiently resistant to the retort treatment.

(Comparative Example) As a paper base material for a container,
Printing was performed on coated ball base paper of 10 g / m ² , and a polyethylene resin was extruded on the content-filled surface and laminated by lamination.

This was punched out so as to have an expanded shape of a hexahedral container having a top portion, a body portion and a bottom portion and having a full capacity of 300 ml and having a full capacity of 300 ml. After filling the food with fluidity, sealing the filling port and heating the obtained container with hot water of 90 ° C. for 40 minutes,
The mixture was cooled with room temperature water at 20 ° C. for 1 hour.

The container absorbs a large amount of water from the end of the outer paper container, causing delamination between the polyethylene resin layer and the paper,
In addition, the container lost strength and was not usable.

(Other Embodiments) The present invention is not limited to the above-described embodiments, and can be implemented in various forms in the implementation stage without departing from the spirit of the invention. It is. In addition, the embodiments may be implemented in combination as appropriate as much as possible, in which case the combined operation and effect can be obtained. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent features. For example, even if some components are deleted from all the components shown in the embodiment, at least one of the problems described in the section of the problem to be solved by the invention can be solved, and the effects of the invention can be solved. In the case where (at least one of) the effects described in the section is obtained, a configuration from which this component is deleted can be extracted as an invention.

[0072]

As described above, according to the present invention, as compared with conventional papers having hot water resistance, the strength in the state of absorbing moisture with hot water can be greatly improved, and the boil sterilization treatment, retort It is possible to provide a paper container having extremely excellent hot water resistance, which can be cooked by sterilization treatment and hot water treatment.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a paper container having hot water resistance according to the present invention.

FIG. 2 is a perspective view showing another embodiment of the paper container having hot water resistance according to the present invention.

FIG. 3 is a perspective view showing another embodiment of the paper container having hot water resistance according to the present invention.

FIG. 4 is a perspective view showing another embodiment of the paper container having hot water resistance according to the present invention.

FIG. 5 is a perspective view showing another embodiment of a paper container having hot water resistance according to the present invention.

FIG. 6 is a perspective view showing another embodiment of a paper container having hot water resistance according to the present invention.

FIG. 7 is a perspective view showing another embodiment of a paper container having hot water resistance according to the present invention.

FIG. 8 is a perspective view showing another embodiment of a paper container having hot water resistance according to the present invention.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Masao Nakajima 1-5-1, Taito, Taito-ku, Tokyo Letterpress Printing Co., Ltd. (72) Kenichi Niimi 1-1-5-1 Taito, Taito-ku, Tokyo Inside Toppan Printing Co., Ltd. (72) Inventor Yoshiki Ueda Inside Toppan Printing Co., Ltd. 1-1-1, Taito, Taito-ku, Tokyo

Claims (16)

[Claims] 1. A paper container having hot water resistance, characterized by using paper whose dimensional change in a paper wet state under a wet condition of immersion in hot water of 90 ° C. or more for 1 hour is 4% or less. . 2. The ring crush strength (JIS P8
126) A paper container having hot water resistance, characterized by using paper having 0.9N or more. 3. The paper has a folding yield strength of 0.6 N / in a wet state of paper under humid conditions of immersion in hot water of 90 ° C. or more for 1 hour.
A paper container having hot water resistance, wherein a paper having a length of 40 mm or more is used. 4. A paper having a folding yield strength in a wet state of paper / folding yield strength in a dry state of 10% or more under a wet condition of immersion in hot water of 90 ° C. or more for 1 hour. Paper container having hot water resistance. 5. The paper container having hot water resistance according to claim 1, wherein the paper has a tensile strength at break of 30 N / in a wet state under a wet condition of immersion in hot water of 90 ° C. or more for 1 hour.
A paper container having hot water resistance, characterized by using paper of 15 mm or more. 6. The paper container having hot water resistance according to claim 1, wherein the paper is immersed in hot water of 90 ° C. or more for 1 hour, and the paper is immersed for 1 hour in a wet state to obtain a tensile strength at break / dry state. A paper container having hot water resistance, wherein a paper having a tensile breaking strength of 10% or more is used. 7. A paper having hot water resistance, characterized in that a paper having a tensile elongation at break of 10% or more in a wet state of paper under a wet condition of immersion in hot water of 90 ° C. or more for 1 hour is used. Container. 8. The method according to claim 2, wherein
In the paper container having the hot water resistance described in the paragraph, the surface water absorption (JIS P8140 Cobb method) in a paper wet state under a wet condition of immersion in hot water of 90 ° C. or more for 1 hour is 100 g.
/ M ² or less, a paper container having hot water resistance. 9. The method according to claim 2, wherein
In the paper container having hot water resistance described in the paragraph, the total water absorption of hot water of 90 ° C. or more is 80% by weight with paper.
A paper container having hot water resistance, characterized by using the following paper. 10. The paper container according to claim 1, wherein the paper container body is obtained by impregnating and coating a resin. A paper container having hot water resistance, comprising: 11. The paper container having hot water resistance according to claim 1, wherein the paper container main body is provided with a thermoplastic resin layer at least inside. Paper container having hot water resistance. 12. The paper container having hot water resistance according to claim 1, wherein the paper container main body has a shape having an upper opening. Paper container having hot water resistance. 13. The paper container having heat and water resistance according to claim 1, wherein the paper container main body has a cylindrical shape having at least a top portion, a body portion, and a bottom portion. A paper container having hot water resistance. 14. The paper container having heat and water resistance according to claim 1, wherein the paper container main body has at least a top part, a body part, and a bottom part, A paper container having a hot water resistance, wherein the paper container has a hexahedral shape or a roof shape. 15. The hot water resistant paper container according to claim 1, wherein said paper container main body has a bag-like shape. A paper container having: 16. The hot water resistant paper container according to claim 1, wherein the paper container body has a bottle shape. Paper container.