阅读说明：本技术 纸容器 (Paper container ) 是由 中村孝也 小野村和秀 阿曾井荣一 米田芳贵 于 2019-06-28 设计创作，主要内容包括：为了获得能够一边防止握持时的滑落一边不用担心给保管输送等带来麻烦、并且能够迅速且顺畅地倒出液体饮料的纸容器,具备经由主体部纵向折线1、2、3、4连接的主体部正面板5、主体部左右侧面板6、8和主体部背面板7,在通过纵向封口板25形成四角筒状主体部26的纸容器中,将顶部28设为具有主体部正面板5侧低且主体部背面板7侧高的倾斜面S,在倾斜面S形成开口部37而设置孔盖38,使连接主体部正面板5与主体部左右侧面板6、8的主体部纵向折线1、2及连接主体部背面板7与主体部左右侧面板6、8的主体部纵向折线3、4,成为向主体部正面板5的中央方向及主体部背面板7的中央方向分别弯曲的大致对称形状的弯曲线。(In order to obtain a paper container which can prevent slipping off at the time of holding and does not cause trouble in storage and transportation and can pour out liquid beverage quickly and smoothly, the paper container is provided with a main body front panel 5, main body left and right side panels 6, 8 and a main body back panel 7 which are connected via main body longitudinal folding lines 1, 2, 3, 4, in the paper container in which a quadrangular cylindrical main body 26 is formed by a longitudinal sealing plate 25, a top 28 is formed as an inclined surface S having a low main body front panel 5 side and a high main body back panel 7 side, an opening 37 is formed in the inclined surface S to provide a hole cover 38, the main body longitudinal folding lines 1, 2 connecting the main body front panel 5 and the main body left and right side panels 6, 8 and the main body longitudinal folding lines 3, 4 connecting the main body back panel 7 and the main body left and right side panels 6, 8 are bent in a substantially symmetrical shape in the central direction of the main body front panel 5 and the central direction of the .)

1. A paper container comprising a main body front panel, main body left and right side panels and a main body back panel connected by a main body longitudinal fold line, wherein a quadrangular cylindrical main body is formed by a longitudinal seal panel, a pair of top panels opposed to each other with a top transverse fold line interposed therebetween are connected to the upper ends of the main body front panel and the main body back panel, and a pair of side panels opposed to each other with a top transverse fold line interposed therebetween are connected to the upper ends of the main body left and right side panels, the pair of top panels and the pair of side panels are folded and sealed to form a top, a pair of bottom panels opposed to each other with a bottom transverse fold line interposed therebetween are connected to the lower ends of the main body front panel and the main body back panel, and a pair of inner panels opposed to each other with a bottom transverse fold line interposed therebetween are connected to the lower ends of the main body left and right side panels, the method is characterized in that:

the top portion has an inclined surface that is lower on the main body portion front surface plate side and higher on the main body portion rear surface plate side,

an opening is formed in the inclined surface, a hole cover is provided in the opening,

the main body longitudinal folding line connecting the main body front panel and the main body left and right side panels and the main body longitudinal folding line connecting the main body back panel and the main body left and right side panels are bent lines of substantially symmetrical shapes bent in the central direction of the main body front panel and the central direction of the main body back panel, respectively.

2. The paper container of claim 1, wherein: the bent top portion of the main body portion longitudinal fold line formed by the bent line is located above the longitudinal center of the main body portion front surface plate and the main body portion rear surface plate.

3. The paper container of claim 1 or 2, wherein: the left and right side panels of the main body are provided with longitudinal protruding strips formed by mountain-folded longitudinal folding lines.

4. The paper container of any of claims 1 to 3, wherein: the main body back panel, the top panel connected to the upper end of the main body back panel, and the bottom panel connected to the lower end of the main body back panel are divided into two parts in the longitudinal direction at the center of the surface thereof, the longitudinal sealing plate is connected to each of the divided edges of the divided pieces of the main body back panel, the top panel, and the bottom panel, and the longitudinal sealing plate and the other divided edge are sealed to form the quadrangular cylindrical main body.

Technical Field

The present invention relates to a paper container (including a brick-type paper container) having a flat-top type top for containing a liquid beverage such as milk or juice or a paper container having a gable-top type top.

Background

Conventionally, paper containers have been widely used: a flat-top paper container having a top portion comprising a pair of top panels and a pair of side panels folded inward thereof, on a main body portion comprising 4 main body panels and formed in a quadrangular tube shape by sealing with a vertical sealing plate, and a bottom portion comprising a pair of bottom panels and a pair of inner panels folded inward thereof, below the main body portion; or a gable-roof type (gable-top type) paper container having a top portion composed of a pair of gable-roof forming panels and a pair of gable-top forming panels folded inward therefrom, and a bottom portion composed of a pair of bottom panels and a pair of inner panels folded inward therefrom, below the main body portion.

In such a paper container, each body plate of the body formed in a rectangular tubular shape is generally flat, and when the body of the paper container is gripped, the body is not stably held by fingers, and the paper container is difficult to grip.

As a paper container that can cope with such a situation, a paper container has been proposed in which a ridge is formed in parallel with a bottom portion of each body panel of a body, and a recess is formed in a corner portion where adjacent body panels intersect, that is, a ridge portion and a region in the vicinity thereof that is continuous with the ridge (see, for example, patent document 1).

The paper container described in patent document 1 is easy to hold by the projecting strips formed on the body panels of the body, and can be held without slipping.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2007-55637.

Disclosure of Invention

Problems to be solved by the invention

In the paper container described in patent document 1, the holding is easy by the projected strips formed on the body panels of the body, and the paper container can be held without slipping, but the projected strips protrude from the body of the paper container, and therefore, there is a problem that the projected strips may be damaged when the paper container is stored and transported.

Further, the slip resistance is affected by the protruding height of the ridge, and if the height of the ridge is low, the ridge is easy to slip when being held, so that the height of the ridge needs to be increased in order to improve the slip resistance. However, if the height of the ridge is increased, a large gap is formed between the paper containers when the paper containers are arranged, for example, and there is a problem that the amount of storage and the amount of conveyance of the paper containers are reduced, which causes trouble in storage and conveyance of the paper containers, and the like.

The invention aims to provide a paper container which can prevent slipping during holding and is easy to hold, and does not worry about trouble in storage, transportation and the like.

Means for solving the problems

In order to achieve the above object, according to the invention described in claim 1, there is provided a paper container comprising a main body front panel, main body left and right side panels, and a main body back panel, each of which is made of a paper material having a thermoplastic resin laminated on a front surface and a back surface thereof and is connected to each other via a main body longitudinal folding line, wherein a quadrangular cylindrical main body is formed by a longitudinal sealing plate, a pair of top panels opposed to each other via a top transverse folding line are provided at upper ends of the main body front panel and the main body back panel, and a pair of side panels opposed to each other via a top transverse folding line are provided at upper ends of the main body left and right side panels, wherein the pair of top panels and the pair of side panels are folded and sealed to form a top portion, a pair of bottom panels opposed to each other via a bottom transverse folding line are provided at lower ends of the main body front panel and the main body back panel, the pair of bottom panels and the pair of inner panels are folded into the seal and sealed to form a bottom, characterized in that: the top portion has an inclined surface that is lower on the main body front surface side and higher on the main body rear surface side, an opening is formed in the inclined surface, a hole cover is provided in the opening, and the main body longitudinal folding line connecting the main body front surface plate and the main body left and right side surfaces and the main body longitudinal folding line connecting the main body rear surface plate and the main body left and right side surfaces are bent lines having substantially symmetrical shapes that are bent in the center direction of the main body front surface plate and the center direction of the main body rear surface plate, respectively.

In the invention described in claim 2, characterized in that: the curved top portion of the longitudinal fold line of the main body portion as defined in claim 1 is located on an upper side than the longitudinal center of the main body portion front surface plate and the main body portion rear surface plate.

In the invention described in claim 3, characterized in that: the main body portion according to claim 1 or 2, wherein the left and right side panels are provided with longitudinal ridges formed by mountain-folded longitudinal folding lines.

In the invention described in claim 4, characterized in that: the body back panel according to any one of claims 1 to 3, wherein the top panel is connected to an upper end of the body back panel and the bottom panel is connected to a lower end of the body back panel, the top panel is divided into two parts in a longitudinal direction at a center position of a surface of the top panel, the longitudinal sealing plate is connected to one divided edge of the divided pieces of the body back panel, the top panel, and the bottom panel, and the longitudinal sealing plate and the other divided edge are sealed to form the rectangular tubular body.

Effects of the invention

The paper container according to claim 1, wherein the top portion has an inclined surface that is lower on the front surface side and higher on the rear surface side of the main body, an opening is formed in the inclined surface, and a cap is provided in the opening, so that even when the angle of inclination of the paper container is large at the time of pouring the liquid beverage, the opening of the paper container is not closed by the liquid beverage, and the liquid beverage can be poured quickly and smoothly through the cap.

Further, since the main body longitudinal folding line connecting the main body front panel and the main body left and right side panels and the main body longitudinal folding line connecting the main body back panel and the main body left and right side panels are formed as substantially symmetrical bending lines bent in the central direction of the main body front panel and the central direction of the main body back panel, respectively, in the tubular main body formed by the main body front panel, the main body left and right side panels and the main body back panel connected via the main body longitudinal folding line formed as the bending lines, the main body front panel and the main body back panel become convex surfaces bent outward at positions between the bent top portions of the main body longitudinal folding lines facing each other in accordance with the bending angle of the main body longitudinal folding line, and the main body left and right side panels become convex surfaces bent inward at positions between the bent top portions of the main body longitudinal folding lines facing each other in accordance with the bending angle of the main body longitudinal folding A concave surface of the side curve.

Further, when the paper container is gripped, the left and right main body side panels of the tubular main body, which are concave surfaces, are gripped so that the upper side surfaces of the concave surfaces of the left and right main body side panels are caught by fingers, and therefore, the paper container can be reliably prevented from slipping off when gripped, and the paper container can be easily gripped without gripping the paper container.

Further, by pushing the main body front surface plate and the main body rear surface plate of the cylindrical main body from the outside, or by internal pressure of the cylindrical main body, the main body left and right plates that are concave surfaces are pushed out, and even when the central portions of the main body left and right plates are formed substantially linearly in the vertical direction, the main body left and right plates are gripped so as to press the portions between the curved top portions of the main body longitudinal folding lines that face each other, the main body left and right plates are elastically deformed to be concave surfaces, and the paper container can be easily gripped.

Further, since the cylindrical main body portion does not have a projection of the paper container as described in patent document 1, there is no fear of trouble in storage, conveyance, or the like of the paper container.

According to the invention of claim 2, since the curved top portion of the longitudinal fold line of the main body portion described in claim 1 is located above the longitudinal center of the main body portion front surface plate and the main body portion rear surface plate, the paper container can be held in a stable state.

According to the invention described in claim 3, since the longitudinal ridge formed by the mountain-folded longitudinal folding line is provided on the left and right side panels of the main body as described in claim 1 or 2, the ridge serves as a rib to prevent the main body from being expanded by the weight of the liquid beverage contained therein.

Further, when the paper container is gripped, the paper container can be gripped by pushing in a portion between curved top portions of the longitudinal fold line of the main body portion, which portions are opposed to each other, of the projecting portions of the left and right main body portion plates of the cylindrical main body portion, and the left and right main body portion plates are elastically deformed to be concave surfaces.

According to the invention described in claim 4, the top panel connected to the upper end of the main body back panel and the bottom panel connected to the lower end of the main body back panel according to any one of claims 1 to 3 are divided into two parts in the longitudinal direction at the center of the surface thereof, the longitudinal sealing plate is connected to each of the divided edges of the divided pieces of the main body back panel, the top panel and the bottom panel, and the longitudinal sealing plate and the other divided edge are sealed to form the rectangular tubular main body portion.

Drawings

Fig. 1 is a perspective view showing a 1 st example of an embodiment of a paper container according to the present invention.

Fig. 2 is a front view of the 1 st paper container.

Fig. 3 is a side view of the paper container of example 1.

Fig. 4 is an enlarged sectional view a-a of fig. 2 with a portion thereof omitted.

Fig. 5 is a front view showing a state in which the main body left and right panels having a concave shape of the paper container of example 1 are pushed out and the longitudinal center portions of the main body left and right panels are substantially linear.

Fig. 6 is an expanded view of a carton blank for assembling the paper container of example 1.

Fig. 7 is a perspective view showing a 2 nd example of the embodiment of the paper container according to the present invention.

Fig. 8 is a front view of the 2 nd paper container.

Fig. 9 is a side view of the 2 nd paper container.

Fig. 10 is an enlarged B-B sectional view of fig. 8 with a portion thereof omitted.

Fig. 11 is an enlarged cross-sectional explanatory view showing a state where left and right plates of a main body portion of the paper container of example 2 are pushed in and deformed into a concave shape.

Fig. 12 is an expanded view of a carton blank for assembling the 2 nd paper container.

Fig. 13 is a front view showing example 3 of the embodiment of the paper container according to the present invention.

Fig. 14 is a side view of the paper container of example 3.

Modes for carrying out the invention

Hereinafter, embodiments of the paper container according to the present invention will be described in detail with reference to the drawings.

Fig. 1 to 6 show a 1 st example of an embodiment of a paper container according to the present invention, fig. 1 is a perspective view showing the 1 st example paper container, fig. 2 is a front view of the 1 st example paper container, fig. 3 is a side view of the 1 st example paper container, fig. 4 is an enlarged sectional view a-a of fig. 2, in which a part thereof is omitted, fig. 5 is a front view showing a state in which left and right main body panels having a concave shape of the 1 st example paper container are pushed out and longitudinal center portions of the left and right main body panels are substantially linear, and fig. 6 is an expanded view of a carton blank in which the 1 st example paper container is assembled.

The paper container of example 1 is a paper container of the flat top type obtained by assembling a carton blank having an expanded configuration shown in fig. 6 and providing a hole cover.

The carton blank for assembling the paper container of example 1 is made of a paper material having a front surface and a back surface laminated with a thermoplastic resin, and a main body front panel 5, a main body left side panel 6, a main body back panel 7, and a main body right side panel 8 are connected to each other via main body longitudinal folding lines 1, 2, 3, and 4.

A pair of top panels 11, 12 facing each other with top transverse fold lines 9, 10 interposed therebetween are connected to the upper ends of the main body front panel 5 and the main body back panel 7, and a pair of side panels 15, 16 facing each other with top transverse fold lines 13, 14 interposed therebetween are connected to the upper ends of the main body left side panel 6 and the main body right side panel 8.

The top transverse folding lines 13, 14 in this example are inclined such that the height of the body portion left side panel 6 and the body portion right side panel 8 on the body portion front side panel 5 side is lower than the height on the body portion rear side panel 7 side. In addition, a pair of top panels 11, 12 and a pair of side panels 15, 16 are connected alternately via top longitudinal fold lines 33, 34, 35, 36. In this example, the following are formed: the sum of the length of the top longitudinal fold line 33 and the length of the top longitudinal fold line 36 is substantially equal to the length of the top transverse fold line 14, and the sum of the length of the top longitudinal fold line 34 and the length of the top longitudinal fold line 35 is substantially equal to the length of the top transverse fold line 13.

The top panel 11 is formed with an opening 37. The opening 37 is formed by cutting the carton blank, but may be formed by half-cutting without opening. For example, when a paper material formed by laminating a sheet of aluminum on a raw material of a carton blank is used, the opening 37 may be formed by cutting out other layers and leaving only the sheet of aluminum.

A pair of bottom panels 19, 20 opposed to each other via bottom transverse folding lines 17, 18 are connected to the lower ends of the main body front panel 5 and the main body back panel 7, and a pair of inner panels 23, 24 opposed to each other via bottom transverse folding lines 21, 22 are connected to the lower ends of the main body left side panel 6 and the main body right side panel 8.

The main body back plate 7, the top panel 12 connected to the upper end of the main body back plate 7, and the bottom panel 20 connected to the lower end of the main body back plate 7 are divided into two parts in the longitudinal direction at the center of the surface thereof, and a longitudinal sealing plate 25 sealed with the divided edges of the divided one main body back plate 7a, the divided one top panel 12a, and the divided one bottom panel 20a is connected to the divided edges of the divided other main body back plate 7b, the divided one top panel 12b, and the divided one bottom panel 20 b.

The main body longitudinal folding lines 1 and 2 connecting the main body front panel 5, the main body left side panel 6, and the main body right side panel 8 are bending lines of a substantially symmetrical shape bent in a substantially "く" shape toward the center of the main body front panel 5. Similarly, the body portion vertical folding lines 3 and 4 connecting the body portion back surface plate 7, the body portion left side surface plate 6, and the body portion right side surface plate 8 are also bent lines having a substantially symmetrical shape bent in a substantially "く" shape toward the center of the body portion back surface plate 7.

In example 1, the curved top portions T of the body portion longitudinal folding lines 1, 2, 3, and 4 formed by the bending lines are located above the longitudinal centers of the body portion front surface plate 5 and the body portion rear surface plate 7.

In assembling the carton blank having such an expanded structure, first, the main body longitudinal folding lines 1, 2, 3, and 4 are mountain-folded, and the longitudinal sealing plate 25 connected to the divided edge of the divided one main body back plate 7a, the top plate 12a, and the bottom plate 20a and the divided edge of the other main body back plate 7b, the top plate 12b, and the bottom plate 20b are sealed, thereby forming the quadrangular cylindrical main body 26.

Next, the pair of bottom panels 19 and 20 connected to the lower ends of the main body front panel 5 and the main body back panel 7, and the pair of inner panels 23 and 34 connected to the lower ends of the main body left side panel 6 and the main body right side panel 8 of the tubular main body 26 are folded and sealed to form the bottom 27.

After the liquid beverage is filled, the pair of top panels 11 and 12 connected to the upper ends of the main body front panel 5 and the main body back panel 7, and the pair of side panels 15 and 16 connected to the upper ends of the main body left side panel 6 and the main body right side panel 8 are folded, sealed, and sealed to form the top 28.

At this time, in this example, the length of the top longitudinal folding line 33 is substantially equal to the length of the top transverse folding line 14 when added to the length of the top longitudinal folding line 36, and the length of the top longitudinal folding line 34 is substantially equal to the length of the top transverse folding line 13 when added to the length of the top longitudinal folding line 35, so that the top formation panels 11 and 12 form the flat top 28. In the top transverse folding lines 13 and 14 of this example, the height of the body front side panel 5 side is lower than the height of the body rear side panel 7 side in the body left side panel 6 and the body right side panel 8, and therefore the top 28 as a whole forms the inclined surface S in which the body front side panel 5 side is lower and the body rear side panel 7 side is higher.

In the thus assembled carton blank, the hole cover 38 is provided in the opening 37. The orifice cover 38 may be a known orifice cover having an outlet 39, and is not particularly limited. In this example, the hole cover 38 includes an outlet portion 39, a lid portion 40, and a flange portion (not shown) that is bonded to the outer surface or the inner surface of the top panel 11 and fixes the hole cover 38 to the opening portion 37. The hole cover 38 may be fixed to the opening 37 by a known fixing method, and is not particularly limited. In this example, before the top portion 28 is formed, the hole cover 38 is inserted into the opening 37 so that the outlet portion 39 and the lid portion 40 protrude above the top portion 28, and the upper surface of the flange portion is brought into contact with the inner surface side of the top panel 11 and bonded thereto. However, the lower surface of the flange portion may be brought into contact with the outer surface of the top portion 11 and fixed by adhesion.

According to the paper container assembled as described above, since the top portion 28 has the inclined surface S in which the main body front surface plate 5 side is low and the back surface plate 7 side is high, the opening 37 is formed in the top surface plate 11 constituting the inclined surface S, and the lid 38 is provided in the opening 37, even if the inclination angle of the paper container is increased when pouring the liquid beverage, the opening 37 of the paper container is not blocked by the liquid beverage, and the liquid beverage can be quickly and smoothly poured through the lid 38.

Further, the main body longitudinal folding lines 1, 2 connecting the main body front panel 5 and the main body left and right side panels 6, 8 and the main body longitudinal folding lines 3, 4 connecting the main body back panel 7 and the main body left and right side panels 6, 8 are bent lines of substantially symmetrical shape respectively in the central direction of the main body front panel 5 and the central direction of the main body back panel 7, so that in the tubular main body 26 formed by the main body front panel 5, the main body left and right side panels 6, 8 and the main body back panel 7 connected via the main body longitudinal folding lines 1, 2, 3, 4, the main body front panel 5 is a convex surface X bent outward at a portion between the bent top portions T of the main body longitudinal folding lines 1, 2 in accordance with the bending angle of the main body longitudinal folding lines 1, 2, and the main body back panel 7 is a convex surface X bent outward at a portion between the main body longitudinal folding, 4, a convex surface X (see fig. 3) curved outward at a portion between the curved top portions T.

The body left side panel 6 is a concave surface Y curved inward at a portion between the curved top portions T of the body longitudinal folding lines 2 and 3 in accordance with the bending angle of the body longitudinal folding lines 2 and 3, and the body right side panel 8 is a concave surface Y curved inward at a portion between the curved top portions T of the body longitudinal folding lines 1 and 4 in accordance with the bending angle of the body longitudinal folding lines 1 and 4 (see fig. 2.).

Since the body left and right side surfaces 6, 8 of the tubular body 26 are formed into the concave surface Y in this way, when the paper container is gripped, the body left and right side surfaces 6, 8 formed into the concave surface Y of the tubular body 26 are gripped so that the upper side surfaces of the concave surfaces Y of the body left and right side surfaces 6, 8 are caught by fingers, and therefore, slipping off when the paper container is gripped can be reliably prevented.

Further, by pushing the body front panel 5 and the body back panel 7 of the cylindrical body 26 from the outside, by the internal pressure of the cylindrical body 26, or the like, the body left and right side panels 6 and 8 that become the concave surface Y are pushed out, and even when the center portions of the body left and right side panels 6 and 8 are vertically aligned (see fig. 5), by grasping the body left and right side panels 6 and 8 so as to press the portions between the curved top portions T of the body longitudinal folding lines 2 and 3 in the body left side panel 6 and the portions between the curved top portions T of the body longitudinal folding lines 1 and 4 in the body right side panel 8, the body left and right side panels 6 and 8 are elastically deformed so as to become the concave surface Y, and the paper container can be easily gripped.

In example 1, the curved top portions T of the main body longitudinal folding lines 1, 2, 3, and 4 formed by the curved lines are located above the longitudinal center of the main body front panel 5 and the main body rear panel 7, and therefore the paper container can be gripped in a stable state.

Fig. 7 to 12 show a 2 nd example of the embodiment of the paper container according to the present invention, fig. 7 is a perspective view showing the paper container of the 2 nd example, fig. 8 is a front view of the paper container of the 2 nd example, fig. 9 is a side view of the paper container of the 2 nd example, fig. 10 is an enlarged sectional view B-B of fig. 8, which is partially omitted, fig. 11 is an enlarged sectional explanatory view showing a state where left and right panels of a main body portion of the paper container of the 2 nd example are pushed in and deformed into a concave shape, and fig. 12 is an expanded view of a carton blank in which the paper container of the 2 nd example is assembled.

The same components as those in example 1 are denoted by the same reference numerals and their description is omitted with respect to the paper container of example 2, and only the components different from those in example 1 will be described.

The paper container of example 2 is a paper container having a flat top as in example 1, and is obtained by assembling a carton blank having an expanded configuration shown in fig. 12 and providing a hole cover.

The carton blank for assembling the paper container of example 2 is provided with a longitudinal folding line 30 in the longitudinal direction on the left body panel 6, which is connected to the top transverse folding line 13 and the bottom transverse folding line 21 and is mountain-folded to form a protruding strip portion 29, and also provided with a longitudinal folding line 32 in the longitudinal direction on the right body panel 8, which is connected to the top transverse folding line 14 and the bottom transverse folding line 22 and is mountain-folded to form a protruding strip portion 31. The positions of the longitudinal folding lines 30 and 32 formed on the left and right body side panels 6 and 8 are not particularly limited, but in this example, the longitudinal folding lines 30 and 32 are formed at the center portions of the left and right body side panels 6 and 8.

The other structure is the same as that of the carton blank of example 1 shown in fig. 6.

In the assembly of the paper container of example 2 using the carton blank having such an expanded structure, first, the longitudinal folding line 30 continuous with the top transverse folding line 13 and the bottom transverse folding line 21 provided in the body left side panel 6 is mountain-folded to form the longitudinal protruding portion 29 in the body left side panel 6, and similarly, the longitudinal folding line 32 continuous with the top transverse folding line 13 and the bottom transverse folding line 21 provided in the body right side panel 8 is mountain-folded to form the longitudinal protruding portion 31 in the body right side panel 8. In this example, the longitudinal folding lines 30 and 32 are formed at the center portions of the left and right body side panels 6 and 8, and therefore the protruding portions 29 and 31 are formed at the center portions of the left and right body side panels 6 and 8.

The other carton blanks were assembled in the same manner as in example 1.

The structure of the hole cover provided in the paper container and the fixation of the opening are also the same as in example 1.

According to the paper container thus assembled, the main body longitudinal folding lines 1, 2 connecting the main body front panel 5 and the main body left and right side panels 6, 8 and the main body longitudinal folding lines 3, 4 connecting the main body back panel 7 and the main body left and right side panels 6, 8 are bent lines having substantially symmetrical shapes respectively in the central direction of the main body front panel 5 and the central direction of the main body back panel 7, so that in the tubular main body 26 formed by the main body front panel 5, the main body left and right side panels 6, 8 and the main body back panel 7 connected via the main body longitudinal folding lines 1, 2, 3, 4, the main body front panel 5 is formed into the convex surface X bent outward at the portion between the bent top portions T of the main body longitudinal folding lines 1, 2 in accordance with the bending angle of the main body longitudinal folding lines 1, 2, and the main body back panel 7 is formed into the, The bending angle of 4 is a convex surface X (see fig. 9) which is bent outward at a portion between the bent top portions T of the body longitudinal folding lines 3, 4.

The main body left panel 6 is formed to have a substantially straight longitudinal central portion by the ridge portion 29 formed by mountain-folding the longitudinal folding line 30, and the main body left panel 8 is also formed to have a substantially straight longitudinal central portion by the ridge portion 31 formed by mountain-folding the longitudinal folding line 32 (see fig. 8).

In this way, the longitudinal ridges 29 and 30 provided at the center portions of the left and right side plates 6 and 8 of the main body are ribs, respectively, and the main body can be prevented from being expanded by the weight of the liquid beverage contained in the tubular main body 26. In this example, the protrusions 29 and 30 are formed in the center portions of the left and right side panels 6 and 8 of the main body, which are the portions of the paper container where the main body is most inflated when inflated.

When the paper container is gripped, the paper container can be easily gripped by pressing the portion between the curved top portions T of the body portion longitudinal folding lines 2 and 3 in the body portion left plate 6 and the portion between the curved top portions T of the body portion longitudinal folding lines 1 and 4 in the body portion right plate 8, and the body portion left and right plates 6 and 8 are elastically deformed to be deformed into the concave surface Y (see fig. 11).

Other effects are the same as in example 1.

Fig. 13 and 14 show example 3 of the embodiment according to the present invention, fig. 13 is a perspective view showing example 3 of the embodiment of the paper container according to the present invention, and fig. 14 is an expanded view of a carton blank for assembling the paper container of example 3.

The same components as those in example 1 or example 2 are denoted by the same reference numerals and description thereof is omitted with respect to the paper container of example 3, and only the components different from those in example 1 and example 2 will be described.

The paper container of example 3 is a paper container of gable-top type, and is obtained by assembling a carton blank having an expanded configuration shown in fig. 14 and providing a hole cover.

The carton blank for assembling the paper container of example 3 was formed: the length of top longitudinal fold line 33, when added to the length of top longitudinal fold line 36, will be longer than the length of top transverse fold line 14, and the length of top longitudinal fold line 34, when added to the length of top longitudinal fold line 35, will be longer than the length of top transverse fold line 13.

The other structure is the same as that of the 2 nd carton blank shown in fig. 12.

The top 28 of the paper container of example 3 using the carton blank having such an expanded structure is formed into a gable top type having an inclined surface S in which the main body front panel 5 side is low and the rear panel 7 side is high by folding the pair of side panels 15 and 16 between the pair of top panels 11 and 12 connected to the upper ends of the main body front panel 5 and the main body rear panel 7 after filling the liquid beverage, and sealing the lid.

The other carton blanks were assembled in the same manner as in example 1.

The structure of the hole cover provided in the paper container and the fixation of the hole cover to the opening are also the same as in example 1.

According to the paper container assembled as described above, since the top portion 28 has the inclined surface S in which the main body front surface plate 5 side is low and the back surface plate 7 side is high, the opening 37 is formed in the top surface plate 11 constituting the inclined surface S, and the lid 38 is provided in the opening 37, even if the inclination angle of the paper container is increased when pouring out the liquid beverage, the opening 37 of the paper container is not closed by the liquid beverage, and the liquid beverage can be quickly and smoothly poured out through the lid 38.

Description of the reference symbols

1. 2, 3 and 4 longitudinal fold lines of the main body part; 5 a main body front panel; 6 a left panel of the main body; 7a main body back panel; 7a divided body back plate; 7b divided into another body back plate; 8 body portion right side panel; 9. 10 top transverse fold lines; 11. 12a top panel; 12a top panel; 12b another top panel; 13. 14 a top transverse fold line; 15. 16 side panels; 17. 18 bottom transverse fold line; 19. 20a bottom panel; 20a bottom panel; 20b another bottom panel; 21. 22 a bottom transverse fold line; 23. 24 an inner panel; 25 longitudinal sealing plates; 26 a cylindrical main body portion; 27 bottom part; 28, a top part; 29 protruding strip parts; 30 longitudinal fold lines; 31 protruding strip parts; 32 longitudinal fold lines; 33. 34, 35, 36 top longitudinal fold lines; 37 an opening part; a 38-hole cover; 39 an outlet port; 40 a cover portion; a T-bend top; an X convex surface; a Y concave surface; an S inclined plane.