HK1232196B - Paper bag - Google Patents

Description

paper bag

Technical Field

The invention relates to a paper bag, preferably a valve paper bag for bulk material such as cement, gypsum, granular matter, animal feed or the like, the paper bag having a base, preferably a cross-base or laminated base, and an upper part arranged opposite the base, in which a valve hose for filling the paper bag is optionally arranged.

Background Art

Such paper bags are known, for example, from EP 1 858 769 B1. Typical sizes of 5 kg, 10 kg or 25 kg are particularly common commercially. They have one or more paper layers made of paper or a paper composite and/or coated paper.

A valve hose is optionally provided for filling such bags, which enters the upper working section and is located above the filler nozzle for filling. Rapid escape of gas during the filling process is very important for fast and economical filling. On the other hand, the bag should be as leak-proof as possible after filling. To achieve better product protection or longer-term product stability of the filling material, a barrier layer (as described in EP 1 858 769 B1) can be located between the inner and outer layers of paper.

It has been found that known bags cannot ensure adequate product protection for sensitive filling materials, such as, for example, fast-bonding products in the building material sector or foods that must be protected from aroma loss.

In addition, there is a need for so-called weather-resistant paper bags, which have outwardly disposed sides with waterproof or weather-resistant material properties to ensure weather resistance within a specific period of time. In this embodiment, it is also necessary to provide sufficient ventilation of the paper bag during the filling process.

Summary of the Invention

The present invention therefore relates to an improvement of known paper bags in order to meet the above-mentioned needs. In particular, the improved paper bag should ensure enhanced product protection and/or prolonged product stability of the filling material and/or increased weather resistance of the packaging material, while at the same time achieving economical production and rapid ventilation during filling.

This object is achieved with the paper bag according to the invention.

According to this embodiment of the present invention, a paper bag comprises at least one paper layer having an overlapping portion that is sealed and adhesively bonded toward the interior of the bag. In this regard, the layer of the paper layer facing the interior of the bag has an air-permeable region in the overlapping region that is covered by the layer of the paper layer facing the exterior of the bag. The at least one paper layer has a weather-resistant coating, at least partially, facing the exterior of the bag. Weather-resistant coatings are considered to be watertight or at least water-repellent materials. The bond can be watertight and/or airtight.

This embodiment provides a so-called weather-resistant bag, which significantly improves the ability of the paper bag to resist weather influences and can also protect the filling material filled in from external influences for a sufficient time when stored outdoors. In particular, it can effectively protect the filling material from moisture or rain.

The weather-resistant coating can be watertight/water-repellent or, ideally, additionally airtight to additionally seal the paper bag and prevent the passage of air, oxygen, CO2, or gaseous water. The coated paper layer also has an overlap, and the overlapped edges preferably extend parallel to the side edges of the paper bag, so that the overlap extends from the base to the upper portion in the form of an overlapping strip.

With the paper bag according to the invention, the overlapping parts of the coated paper layers are adhesively bonded sealingly toward the bag interior, i.e., in the region of the overlapping parts, the layer of the inner layer facing the bag interior is adhesively bonded to the layer of the coated paper layer facing the bag exterior, and the bond is located toward the bag interior in the edge region of the overlapping parts.

The bonding is certainly advantageously placed directly at the edge of the overlap, but the bonding need not be located directly at the edge of the overlap towards the inside of the bag. The bonding can also be moved away from the edge of the overlap, since in this case the effect intended by the invention can still be achieved.

In the overlap region, the coated paper layer facing the bag interior has a permeable area or an area with higher permeability than the rest of the paper layer. This permeable area is covered by the overlap layer facing the bag exterior. This configuration allows gas to escape when the bag is filled with the filling material and to escape toward the outside of the overlap, since the gas flow-blocking bonds are positioned toward the bag interior. The bonds toward the bag interior thus serve to direct the gas flow and stabilize the coated paper layer in the overlap region—in other words, they help hold the ends of the material together in the overlap region. This ensures that gas that escapes through the permeable area during filling completely exits the overlap region to the outside. Furthermore, stability in the overlap region is increased, and the sealing properties of the filled state are enhanced.

Furthermore, the overlap prevents the filling material from escaping. A suitable configuration of the breathable areas ensures that the corresponding filling material is retained in the bag, while only or predominantly gas can escape through the breathable areas. When the bag is filled, the breathable areas are covered by the outer layer of the inner layer in the overlap area, thus preventing substances or liquids from penetrating from the outside.

Embodiments according to the invention achieve good ventilation during filling while at the same time achieving high product protection against external influences.The outer coating provides sufficient protection of the filling material against external influences such as moisture and water.

The aforementioned objectives are also achieved by a paper bag according to the present invention. The paper bag accordingly comprises at least one coated paper layer having an airtight coating facing the bag interior. Furthermore, the coated paper layers have an overlapping portion that is sealedly bonded toward the bag interior, and in the region of the overlapping portion, the layer of the coated paper layer facing the bag interior has an air-permeable area that is covered by the layer of the coated paper layer facing the bag exterior. The configuration of the overlapping portion thus corresponds to the aforementioned first embodiment of the paper bag according to the present invention. The difference from the first embodiment is that the paper layer with the overlapping portion does not necessarily have an outwardly disposed coating, but rather is provided with an inner airtight coating. Furthermore, according to the present invention, at least one conventional layer, in particular a conventional layer composed of paper or a paper composite material, is provided between the filler space and the at least one paper layer with the overlapping portion.

The hermetic coating therefore does not have to be in direct contact with the filler material, but can instead provide an intervening layer, in particular a paper layer. The hermetic coating prevents the penetration of significant quantities of air, oxygen, _CO₂ , or gaseous water from the outside, which could damage or destroy the filler material. It is precisely these gases that are primarily responsible for damage to sensitive materials or for the reduced storage stability of such fillers.

The paper bag embodiment according to the present invention also includes other advantageous configurations.

In advantageous embodiments, the coated paper layer can be coated on both sides. In this regard, the first embodiment also applies to the outer coated paper layer, which can additionally include an inwardly applied airtight coating. The second embodiment also applies to the outer coated paper layer, which can be provided with an outwardly applied water-repellent or waterproof coating in addition to the inwardly applied airtight coating. This embodiment, in which at least one paper layer is coated on both sides, is particularly suitable for single-layer paper bags consisting of only a single paper layer. Naturally, a double-layer coated paper layer is also conceivable for multi-layer paper bags.

As an alternative to double-sided coating, it is possible to provide, in addition to the paper layer with the coating on the outside, a further paper layer, which also includes the described overlapping portion with the air-permeable area and the one inwardly disposed coating. The same applies to a second embodiment variant of the invention, in which, in addition to the at least one paper layer with the inwardly disposed airtight coating, a further paper layer is arranged, which includes the described overlapping portion and an outwardly disposed coating, in particular a water-repellent or waterproof coating. These advantageous embodiments provide airtight paper bags that, on the one hand, prevent the ingress of considerable amounts of oxygen, _CO₂ , or gaseous water into the filling material from the outside, while at the same time providing a certain degree of weather resistance for outdoor storage.

In addition to the coated paper layers with overlapping sections, one or more conventional inner or outer layers can naturally be provided in the vertical paper or paper composite layers. Layers made of other materials or composite materials are also conceivable. These layers are to be understood as conventional layers that either do not have overlapping sections or, if they do, do not have any separate air-permeable areas.

The air-permeable area of the coated paper layer is ideally provided with one or more perforations, preferably formed by needle punching and/or by one or more slits. This ensures sufficient air exchange through the coated paper layer. In another variant, the perforations can be formed as microperforations, which are produced, for example, electrically or chemically and are known from cigarette paper.

The air-permeable areas of the coated paper layer can alternatively be provided by a highly porous material, ie the paper layer features different material properties in the air-permeable areas, which allow a gas exchange or a higher gas exchange compared to the air-impermeable areas.

Furthermore, it is conceivable to design the coated paper layer to be air-permeable in the air-permeable regions due to regional omissions of the coating.

A wide overlap allows for a larger surface area of breathable area in the overlapped area and thus better ventilation during filling. A disadvantage of a larger overlap is a higher material consumption for the inner layer. In this conflict of objectives, it has proven advantageous if the overlapped portion of the inner layer accounts for at least 3%, more advantageously at least 10%, and even more advantageously at least 17%, but not more than 25%, of the bag's circumference.

In another preferred embodiment, the inwardly disposed coating and/or the outwardly disposed coating, i.e., the airtight coating and/or the waterproof/watertight coating, is composed of multiple layers. The airtight coating preferably comprises a metallized film and/or a metal film. Such metallized films or metal films provide particularly good airtightness. Aluminum is a particularly suitable metallized material. Metallized gas barriers provide particularly good aroma protection in the food industry.

The use of at least one lacquer layer and/or at least one wax layer and/or at least one plastic layer and/or at least one oil layer and/or also a metal layer or metal film is particularly suitable for the provision of a waterproof or water-repellent coating. For multi-layer embodiments of the coating of the coated paper layer, additional layers can preferably be applied via a waterproof, water-repellent or airtight coating, which are intended to provide protection for the underlying coating. This can thus prevent, for example, damage to the metal film or wax layer.

The airtight coating advantageously also forms a liquid barrier, thereby also achieving a seal against the ingress of water.

In another preferred embodiment, additional bonds are additionally present in the middle region and/or in the edge regions of the overlapping portion, facing the outside of the bag. These bonds further stabilize the overlapping region. It is conceivable that at least one of these bonds is configured to be at least partially permeable, i.e., breathable, toward the outside of the bag, advantageously by intermittent bond lines along the edge of the overlapping portion, facing the outside of the bag.

In a particularly advantageous embodiment of the invention, in addition to the bond provided toward the bag interior, a central intermittent bond line can be provided, while the bond provided toward the bag exterior in the overlapped edge region is continuous and thus sealing. In this case, it is advantageous if the coated paper layer facing the bag exterior also has an air-permeable region in the overlapped region. This air-permeable region is then provided in the region between the bond provided at the outer edge and the central bond.

This breathable area can also be produced, for example, by omitting a coating and/or by configuring the paper layer with a high-porosity material in this area. The area can be equally completed by providing one or more perforations. The perforations are ideally designed in a manner similar to the perforations of the layer facing the inside of the bag. Advantageous embodiments ensure additional protection because they also ensure a hermetic seal of the outer overlapping portion relative to the outside. However, in order to allow for gas exchange with the outside, the outer overlapping portion must also be equipped with a corresponding breathable area. Gas exchange between the inwardly disposed breathable embodiment of the inner paper layer and the outer paper layer configured to be breathable on the outside occurs through an intermediate bond, which is breathable, that is, it is designed as a discontinuous adhesive strip. The breathable areas of the overlapping layers facing the inside of the bag and facing the outside of the bag are ideally not on top of each other or only slightly or partially overlap each other to create angled gas channels from the inside to the outside.

In another preferred embodiment, the paper bag or the individual paper layers have a plurality of overlapping sections according to the invention, particularly preferably an overlapping section according to the invention on the front side of the bag and a further overlapping section according to the invention on the back side of the bag. This improves the ventilation of the bag during filling and allows the ventilation of the bag to be distributed on both sides.

In other preferred embodiments, the paper bag according to the present invention has an additional paper layer or a layer made of another material suitable for bag manufacture outside the coated paper layer. These layers must also be configured to allow gas to escape to the outside during filling. Suitable materials, preferably paper, coated paper, film, and/or coated film, are contemplated for bag manufacture. This is particularly useful for paper bags coated on the outside. This covering provides, for example, additional protection for transport. To achieve weather resistance, this additional covering is removed, and the at least one paper layer with an outwardly applied waterproof coating then forms the outermost surface of the paper bag.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present invention will be explained in more detail with reference to the following drawings. The drawings show:

FIG1 is a schematic plan view of a valve bag having a base and an upper portion according to the present invention;

FIG2 a is a schematic cross-sectional view through a paper bag according to the present invention, taken along line A-A according to FIG1 ;

Figures 2b and 2c are two other cross-sectional views taken along line A-A according to alternative embodiments;

FIG3 is a coated paper layer according to one of the embodiments of FIG2a, 2b, 2c, with an enlarged section of the overlapping portion, the overlapping portion having a bond;

FIG4 is an enlarged view of the layer design of a coating according to the present invention; and

5 is a tubular section of a coated paper layer of a valve bag according to the embodiment of FIG. 2 a .

DETAILED DESCRIPTION

FIG1 shows a paper bag 10 according to the invention having a crossed bottom part 2 and an upper part 3, wherein the bottom part 2 and the upper part 3 are folded onto the front side 5 of the paper bag 10. The rear side of the bag is located below the front side 5 and is not visible here. A valve tube 4 is inserted into the upper part 2.

The basic principle of the paper bag according to the invention shown in Figure 1 is that it can have a single-layer or multi-layer design. In the case of Figure 1, the paper bag comprises two layers, which can be easily identified in the cross-sectional view of Figure 2a taken along line A-A.

Figure 2a shows a preferred embodiment of a paper bag according to the present invention, which is a multi-layer bag. The paper bag comprises an outwardly disposed coated paper layer 20, which has an overlap 22 with adhesive points 24. The sealing bond 24 is formed toward the interior of the bag. The paper layer 20 also has an outwardly disposed coating having waterproof material properties. The coating is particularly watertight or water-repellent. Furthermore, the embodiment according to Figure 2a includes an inwardly disposed layer 18, which is composed, for example, of paper or a paper composite material. This paper layer also has an overlap 19 with adhesive points 25. A comparison of the two overlaps 19 and 22 shows that the overlap 22 is significantly wider. The two paper layers 20 form the tubular section of the paper bag of Figure 1 between the base 2 and the upper part 3. The wider overlap 22 ensures sufficient ventilation of the paper bag during filling.

Figure 2b shows an alternative variation of the paper bag as an inlaid bag. In this respect, the outer paper layer 20 is designed similarly to the embodiment of Figure 2a.

FIG2 c shows a variant with a coated paper layer 20, which is embedded between two further layers 18 and 21. The overlapping portions of the outwardly and inwardly arranged layers 18 and 21 are likewise formed to be significantly narrower than the overlapping portion 22 of the coated paper layer 20. In this respect, the paper layer 20 can likewise be designed similarly to the paper layers of FIG2 a, 2 b.

It is common practice for the paper layer 20 of Figures 2a, 2b, and 2c to also be coated only inwardly and arranged in a waterproof/water-repellent or airtight manner. It is also conceivable for the paper layer 20 to be coated on both sides, for example, with an airtight coating arranged inwardly and a waterproof/water-repellent coating arranged outwardly. This embodiment is particularly useful for the inlaid bag according to Figure 2b. Generally, the paper layer 20 can naturally also be designed to be uncoated, thereby achieving better air permeability by virtue of the increased overlap 22 relative to the non-overlapping area of the paper layer 20. It is also conceivable to provide additional paper layers with increased overlap in the example of Figures 2a, 2b, and 2c, for example, to provide sufficient ventilation for at least two sides of the bag. It is also conceivable to provide more conventional layers 18, 21.

3 shows the coated paper layer 20 with an enlarged detail of the overlap 22. The pouch interior-facing layer 31 of the coated paper layer 20 overlaps the exterior-facing layer 32 of the coated layer 20 in the overlap region 22. The overlap 22 is sealingly adhesively bonded at its edges facing the pouch interior by means of adhesive 24.

In addition to the adhesive 24, the overlapping portion 22 also includes adhesive points 33, 34, wherein the adhesive points 33 are designed as intermittent adhesive strips in the longitudinal direction of the bag of Figure 1, and the adhesive 34 is a continuous adhesive strip extending in the longitudinal direction. The advantages of the additional adhesives 33, 34 will be considered later with reference to Figure 5.

FIG4 shows, by way of example, the layer design of the coated layer 20. In the case of an inwardly disposed coating, the paper layer has a paper carrier layer 41 on its outer side. The next layer inward is a metallized layer, preferably made of aluminum. The metallized layer 42 is protected by a plastic coating whose core 43 comprises PET (polyethylene terephthalate) or a comparable plastic. Surface layers or surface treatments 44 are provided on both sides of the core 43. A lacquer layer 45 is located between the metallized layer 42 and the surface treatment 44. The corona pretreatment layer 44 then forms the innermost layer facing the bag interior and is applied to the outer surface treatment 44. The plastic coating applied to the metal gas barrier protects the metal layer from damage during bag manufacturing.

The paper layer 20 has a paper carrier layer 41 on its inner side for the coating applied outward. The subsequent outward layer 42a then comprises a waterproof or water-repellent material, preferably a lacquer, oil, wax, plastic, or metal layer (the metal layer is particularly preferably composed of aluminum). Similar to the inner coating, layer 42a is protected by a plastic coating whose core 43 comprises PET (polyethylene terephthalate) or a comparable plastic. Surface layers or surface treatment layers 44 are applied on both sides of core 43. A lacquer layer 45 is located between metallized layer 42 and surface treatment layer 44. A corona pretreatment layer 44 then forms the outermost layer facing the bag exterior and is applied over outer surface treatment layer 44. The plastic coating applied to waterproof or water-repellent layer 42a protects this layer from damage during bag manufacturing. The described layer design can be applied to both sides of carrier material 41 for double-sided coating.

FIG5 now shows a specific embodiment of the overlapping area 22 of the paper layer 20 according to the present invention. The total overlapping area 22 of the layer 31 facing the inside of the bag and the layer 32 facing the outside of the bag are adhesively bonded in an airtight and watertight manner by means of a continuous adhesive strip 24. In addition to the existing bond 34, there is a parallel adhesive strip 33 extending in the middle section of the overlapping portion 22. This adhesive strip 33 is discontinuous, thereby allowing gas to escape to the outside, i.e., from the inside of the bag to the outside.

Perforations 37 in the form of needle punches are provided on the inner layer 31 between the two bonds 24, 33 and form a breathable region in the overlap 22. Consequently, despite the presence of the sealed bonds 24 and the coating of the paper layer 20, gas can escape to the outside during the filling process via the perforations 37 and the intermittent bonds 33. Naturally, breathability can also be achieved by utilizing a highly porous material in this region of the paper layer 20. Furthermore, the applied coating of the paper layer 20 in this region can be omitted in order to thereby provide the desired breathability.

Typically, the outer layer 32 can be cut after the adhesive 33. However, better protection for the filler material is achieved when the outer layer 32 (as shown in FIG5 ) protrudes beyond the adhesive 33 and is adhesively bonded to the inner layer 31 at the edges via a continuous adhesive strip 34. This adhesive strip 34 is also preferably airtight. However, to provide adequate gas egress, the outer-facing overlap region 36 of the outer-facing layer 32 (shown by hatching in FIG5 ) must also be breathable. This can be achieved similarly to the inner layer 31, for example by omitting the coating in region 36 or by using a highly porous paper or having perforations. The venting region 36 and the perforated region 37 are therefore not positioned above each other but are laterally displaced relative to each other.

The gas generated during filling of the bag 10 and escaping through the perforations 37 of the layer 31 facing the bag interior can now escape to the outside through the overlap region 36 facing the bag exterior.

Many advantages are achieved with the present invention. In particular, due to the configuration of the overlapping portion 22, the paper bag can be well ventilated during filling and a high product protection of the filling material or a weather-resistant design of the paper bag 10 can be achieved by means of an airtight coating on the inside or a waterproof coating on the outside of the bag.

For example, the design of the overlap 22 is not only used on the coated layers of the paper bag, but is also provided for layers that do not have a corresponding coating on the inside or outside and generally have breathable properties. The configuration of corresponding overlaps with breathable areas is particularly desirable if the overall material properties of the layer do not have sufficient breathability. In this case, the overlap and the formation of breathable areas with higher breathability relative to the remaining material areas of the layer can achieve better ventilation when filling the paper bag. Against this background, embodiments of the paper bag are advantageous in which at least any layer of any design, such as the inner layer, outer layer, or middle layer, is provided with corresponding overlaps. The bag does not necessarily have to include a coated paper layer or a coated paper layer with overlaps 22.

In another possible embodiment, a layer other than paper can be provided as an additional barrier layer, said layer also being provided with the correspondingly described overlap 22. This barrier layer can be, for example, a plastic film intended to protect the inserted filling material from ingress of liquids or gases. To ensure adequate ventilation during filling of the paper bag, this plastic film or another airtight layer can be provided with a corresponding overlap. The bag need not necessarily include a coated paper layer or a coated paper layer with an overlap 22. Furthermore, additional perforations or air-permeable areas of various designs can be provided in the material area of the plastic film outside the overlap 22.

Claims (34)

1. A paper bag (10) for loose materials, the paper bag having a base (2) and an upper portion (3) disposed opposite to the base, wherein a valve tube (4) for filling the paper bag (10) is arranged in the upper portion, wherein: The paper bag (10) has at least one coated paper layer (20) having overlapping portions (22). The inner layer (31) of the at least one coated paper layer (20) facing the inside of the bag has a breathable area (37) in the region of the overlapping portion (22), wherein the breathable area is covered by the outer layer (32) of the at least one coated paper layer (20) facing the outside of the bag. The at least one coated paper layer (20) has at least regionally a water-repellent/watertight coating (42a) facing the outside of the bag. The first adhesive (24) extends continuously without interruption along the line between the inner layer (31) and the outer layer (32) between the inside of the bag and the breathable area (37). The second adhesive (33) extends discontinuously along the line between the inner layer (31) and the outer layer (32) on opposite sides of the breathable area (37). The third bond (34) extends continuously without interruption along the line between the inner layer (31) and the outer layer (32) on the side of the second bond (33) opposite to the breathable area (37), and The outer layer (32) of the overlapping portion (22) includes a breathable region (36) which is formed with an omitted water-repellent/watertight coating and is located between the second adhesive (33) and the third adhesive (34), such that the breathable region (37) of the inner layer (31) and the breathable region (36) of the outer layer (32) are circumferentially displaced from each other. 2. The paper bag (10) as claimed in claim 1, characterized in that the coated paper layer (20) is coated on both sides with an inwardly disposed airtight coating (42) and an outwardly disposed water-repellent/watertight coating (42a). 3. The paper bag (10) as claimed in claim 1, characterized in that the water-repellent/watertight coating (42a) of the coated paper layer (20) facing the outside of the bag forms the outer surface of the paper bag (10). 4. The paper bag (10) as claimed in claim 1, characterized in that the paper bag (10) has an additional paper layer (20) having an overlapping portion (22), the overlapping portion (22) of the additional paper layer (20) being sealed and bonded towards the inside of the bag, and the inner layer (31) of the additional paper layer (20) facing the inside of the bag having a breathable area (37) in the region of the overlapping portion (22) of the additional paper layer (20), the breathable area (37) of the additional paper layer (20) being covered by the outer layer (32) of the additional paper layer (20) facing the outside of the bag, and the additional paper layer (20) being coated in an airtight manner on the inside and/or in a water-repellent or watertight manner on the outside. 5. The paper bag (10) as claimed in claim 1, wherein the paper bag (10) comprises one or more conventional inner and/or outer layers (18, 21). 6. The paper bag (10) as claimed in claim 5, wherein the one or more conventional inner and/or outer layers are paper layers. 7. The paper bag (10) as claimed in claim 1, wherein the breathable area (37) of the coated paper layer comprises an uncoated area and/or a highly porous material and/or perforations (37), and the perforations are formed by needle punching and/or one or more slits. 8. The paper bag (10) as claimed in claim 1, wherein the overlapping portion (22) of the coated paper layer (20) occupies at least 3% to a maximum of 25% of the outer perimeter of the bag. 9. The paper bag (10) as claimed in claim 1, wherein the overlapping portion (22) of the coated paper layer (20) occupies at least 10% to a maximum of 25% of the outer perimeter of the bag. 10. The paper bag (10) as claimed in claim 1, wherein the overlapping portion (22) of the coated paper layer (20) occupies at least 17% to a maximum of 25% of the outer perimeter of the bag. 11. The paper bag (10) as claimed in claim 1, characterized in that the coating (42, 42a) of the coated paper layer has a multi-layer design. 12. The paper bag (10) as claimed in claim 1, wherein the coating (42, 42a) of the coated paper layer (22) comprises at least one metal layer (42) and/or at least one paint layer (45) and/or at least one oil layer and/or at least one wax layer and/or at least one plastic layer. 13. The paper bag (10) as claimed in claim 1, characterized in that the at least one coated paper layer (20) has an additional overlapping portion (22) configured according to any of the preceding claims, one overlapping portion being formed on the front side (5) of the bag and the additional overlapping portion being formed on the rear side. 14. The paper bag (10) as claimed in claim 1, characterized in that one or more additional material layers (21) appear as a cover over the coated paper layer (20), the additional material layers allowing gas to escape to the outside when the paper bag (10) is filled, and the additional material layers are formed of a material suitable for making bags. 15. The paper bag (10) as claimed in claim 14, wherein the material suitable for making the bag is paper, coated paper, film and/or coated film. 16. The paper bag (10) as claimed in claim 1, wherein the loose material is cement, gypsum, granules or animal feed. 17. The paper bag (10) as claimed in claim 1, wherein the base is a cross bottom or a stacked bottom. 18. A paper bag (10) for loose material, the paper bag having a base (2) and an upper portion (3) disposed opposite to the base, wherein a valve tube (4) for filling the paper bag (10) is arranged in the upper portion, wherein: The paper bag (10) has at least one coated paper layer (20) having an airtight coating (42) facing the inside of the bag. The at least one coated paper layer (20) has an overlapping portion (22). The inner layer (31) of the at least one coated paper layer (20) facing the inside of the bag has a breathable area (37) in the region of the overlapping portion (22), wherein the breathable area is covered by the outer layer (32) of the at least one coated paper layer (20) facing the outside of the bag. The paper bag (10) has a multi-layer design, and the paper layer (18) is arranged between the filling material and at least one coated paper layer (20). The first adhesive (24) extends continuously without interruption along the line between the inner layer (31) and the outer layer (32) between the inside of the bag and the breathable area (37). The second adhesive (33) extends discontinuously along the line between the inner layer (31) and the outer layer (32) on opposite sides of the breathable area (37). The third adhesive (34) extends continuously without interruption along the line between the inner layer (31) and the outer layer (32) on the side of the second adhesive (33) opposite to the breathable area (37). The breathable area (37) of the inner layer (31) is located between the first adhesive (24) and the second adhesive (33), and The outer layer (32) of the overlapping portion (22) includes a breathable region (36) which is formed with an omission of the airtight coating and is located between the second adhesive (33) and the third adhesive (34), such that the breathable region (37) of the inner layer (31) and the breathable region (36) of the outer layer (32) are circumferentially displaced from each other. 19. The paper bag (10) as claimed in claim 18, characterized in that the coated paper layer (20) is coated on both sides with an inwardly disposed airtight coating (42) and an outwardly disposed water-repellent/watertight coating (42a). 20. The paper bag (10) as claimed in claim 18, characterized in that the water-repellent/watertight coating (42a) of the coated paper layer (20) facing the outside of the bag forms the outer surface of the paper bag (10). 21. The paper bag (10) as claimed in claim 18, characterized in that the paper bag (10) has an additional paper layer (20) having an overlapping portion (22) the overlapping portion (22) of the additional paper layer (20) being sealed and bonded toward the inside of the bag, and the inner layer (31) of the additional paper layer (20) facing the inside of the bag having a breathable area (37) in the region of the overlapping portion (22) of the additional paper layer (20), the breathable area (37) of the additional paper layer (20) being covered by the outer layer (32) of the additional paper layer (20) facing the outside of the bag, and the additional paper layer (20) being coated in an airtight manner on the inside and/or in a water-repellent or watertight manner on the outside. 22. The paper bag (10) as claimed in claim 18, wherein the paper bag (10) comprises one or more conventional inner and/or outer layers (18, 21). 23. The paper bag (10) as claimed in claim 22, wherein the one or more conventional inner and/or outer layers are paper layers. 24. The paper bag (10) as claimed in claim 18, wherein the breathable area (37) of the coated paper layer comprises an uncoated area and/or a highly porous material and/or perforations (37), and the perforations are formed by needle punching and/or one or more slits. 25. The paper bag (10) as claimed in claim 18, wherein the overlapping portion (22) of the coated paper layer (20) occupies at least 3% to a maximum of 25% of the outer perimeter of the bag. 26. The paper bag (10) as claimed in claim 18, wherein the overlapping portion (22) of the coated paper layer (20) occupies at least 10% to a maximum of 25% of the outer perimeter of the bag. 27. The paper bag (10) as claimed in claim 18, wherein the overlapping portion (22) of the coated paper layer (20) occupies at least 17% to a maximum of 25% of the outer perimeter of the bag. 28. The paper bag (10) as claimed in claim 18, characterized in that the coating (42, 42a) of the coated paper layer has a multi-layer design. 29. The paper bag (10) as claimed in claim 18, characterized in that the coating (42, 42a) of the coated paper layer (22) comprises at least one metal layer (42) and/or at least one paint layer (45) and/or at least one oil layer and/or at least one wax layer and/or at least one plastic layer. 30. The paper bag (10) as claimed in claim 18, characterized in that the at least one coated paper layer (20) has an additional overlapping portion (22) configured according to any one of claims 18 to 29, one overlapping portion being formed on the front side (5) of the bag and the other overlapping portion being formed on the rear side. 31. The paper bag (10) as claimed in claim 18, characterized in that one or more additional material layers (21) appear as a cover over the coated paper layer (20), the additional material layers allowing gas to escape to the outside when the paper bag (10) is filled, and the additional material layers are formed of a material suitable for making bags. 32. The paper bag (10) as claimed in claim 31, wherein the material suitable for making the bag is paper, coated paper, film and/or coated film. 33. The paper bag (10) as claimed in claim 18, wherein the loose material is cement, gypsum, granules or animal feed. 34. The paper bag (10) as claimed in claim 18, wherein the base is a cross bottom or a stacked bottom.