Fluid material discharge method

Abstract

To provide a fluid material discharge method for discharging a fluid material from a package which comprises a container body storing the fluid material, has an inner surface of the container body coated with a lubricating liquid, has an extremely high discharge performance of the fluid material, and can be easily manufactured without increasing costs.SOLUTION: A fluid material discharge method for discharging a fluid material from a package consisting of a container body 1 storing the fluid material 3 so as to leave a head space 7, wherein a coating layer of a lubricating liquid 30 that is immiscible with the fluid material 3 is formed between an inner surface 1a of the container body 1 and the fluid material 3, and a liquid pool 31 made of the lubricating liquid 30 that forms the coating layer is formed on a peripheral edge part of an upper end surface of the fluid material 3 stored in the container body 1 while the container body 1 is held upright, and the liquid pool causes separation between the fluid material and the container body, thereby discharging the fluid material from the container body 1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for discharging a fluid from a package in which the inner surface of the container body is coated with a lubricating liquid to improve the slipperiness of the fluid. [Background technology]

[0002] Plastic containers are widely used for various purposes because they are easy to mold, can be produced at low cost, etc. In particular, bottle-shaped olefin resin containers, the inner surface of which is made of an olefin resin such as low-density polyethylene and which are formed by direct blow molding, are suitably used as containers for storing viscous slurry or paste-like contents such as ketchup, from the viewpoint of ease of squeezing out the contents.

[0003] Furthermore, in bottles containing viscous contents, the bottles are often stored in an inverted state in order to quickly drain the contents or to use up the contents completely without leaving any residue inside the bottle. Therefore, it is desirable for the viscous contents to quickly fall off the bottle when the bottle is inverted without remaining on the inner wall of the bottle.

[0004] As a bottle that satisfies such requirements, for example, Patent Document 1 proposes a container having hydrophobic oxide fine particles with an average primary particle diameter of 3 to 100 nm attached to the inner surface. Patent Document 2 proposes a lid having a water-repellent film formed on its surface, the water-repellent film having a structure in which oxide microparticles having an average particle size of 5 nm to 100 nm are dispersed and attached to the surface of a resin film formed from resin particles having an average particle size of 1 μm to 20 μm.

[0005] The technologies proposed in the above patent documents all form minute irregularities on the surface that comes into contact with the contents, and the minute irregularities provide water repellency (hydrophobicity). That is, in addition to the hydrophobicity of the material that forms the irregular surface, an air layer is formed in the voids present in the irregular surface, and this air layer is more water repellent than the material that forms the container, resulting in improved non-adhesion to aqueous contents. However, although the formation of such a finely uneven surface improves the non-adhesiveness of aqueous contents, when the contents are in constant contact with the finely uneven surface, moisture is very likely to condense in the recesses of the finely uneven surface, and the recesses become filled with condensed moisture, resulting in a deterioration in slipperiness, and there is a demand for further improvement in slipperiness.

[0006] Furthermore, Patent Document 3 proposes a container whose inner surface is uneven and in which a liquid is stably held. This container utilizes the capillary action of the unevenness to stably hold a layer of liquid on the inner surface of the container, and this liquid layer improves the slipperiness of the contents. However, this technology has difficulties in forming irregularities on the inner surface of the container. Specifically, because these irregularities retain liquid by capillary action, their pitch is extremely small and their height is significantly greater than the pitch. Without this configuration, capillary force would not be dominant, and liquid would fall due to gravity. However, these irregularities are formed by post-processing after molding the container body, such as by spraying a liquid containing dispersed microparticles for forming the irregularities or by etching. Therefore, for containers such as bottles, the process of forming the irregularities after molding the container becomes extremely complicated, inevitably resulting in significant increases in costs.

[0007] Meanwhile, the present inventors have proposed a container that solves the above problem in Patent Document 4. This container also has an uneven surface on the inner surface, and a liquid layer of lubricating liquid is formed on the uneven inner surface, and this liquid layer is used to improve the slipperiness of the contents of the container, which is the same as the technology of Patent Document 3. However, Patent Document 4 has an important feature in that locally protruding portions are formed on the surface of the liquid layer, specifically, the unevenness of the inner surface of the container is reflected on the surface of the liquid layer, and locally protruding portions are formed on the surface of the liquid layer corresponding to the protruding portions on the inner surface of the container. In other words, the liquid layer formed here is a thin layer that just wets the inner surface of the container, and when the contents of the container flow through a part where such a liquid layer is formed, the contents of the container flow in contact with the liquid layer (locally protruding portions) and the air layer present between the locally protruding liquid layers, thereby exhibiting superior slipperiness compared to when the contents of the container flow simply in contact with the liquid layer.

[0008] The technology of Patent Document 4 can of course significantly improve the slipperiness of the container contents. However, what is noteworthy is that the unevenness of the inner surface of the container can be created by molding the container after mixing fine particles that act as a surface-roughening agent into the resin that forms the inner surface of the container, without requiring post-processing after molding the container. That is, the unevenness only needs to retain enough liquid to wet the inner surface of the container, and does not exert capillary forces that would hold the liquid between the unevennesses. Therefore, the pitch of the unevenness is large, for example, greater than the height of the unevenness. As a result, such unevenness can be formed by mixing a certain amount of surface-roughening fine particles into the resin that forms the inner surface of the container and then molding it, eliminating the need for tedious post-processing after molding the container, and offering significant advantages in terms of productivity, manufacturing costs, and the like.

[0009] However, even the technology of Patent Document 4 developed by the present inventors still has problems remaining. That is, in the technology of Patent Document 4, the liquid layer of the lubricating liquid on the inner surface of the container is extremely thin, so it is not suitable for forming a liquid layer by spraying the lubricating liquid onto the inner surface of the container, but the liquid layer is formed by an internal addition method in which the lubricating liquid is mixed with the resin that forms the inner surface of the container and then molded into the container. In other words, the liquid layer is formed by bleeding from the resin layer that forms the inner surface of the container. Such internal addition means is certainly advantageous for forming a thin liquid layer, but it is difficult to form a liquid layer of uniform thickness over the entire inner surface, and parts of the inner surface may be formed where no liquid layer is present, or in some cases, the unevenness of the inner surface may not have the ability to retain liquid, resulting in the formation of a liquid layer of excessive thickness in some parts.This tends to result in variations in the slipperiness of the contents, and further improvement is required.

[0010] Of course, it is possible to form the liquid layer by spraying the lubricating liquid onto the inner surface of the container, but in this case, the amount of liquid forming the liquid layer will be excessive, and after spraying, a process of inverting the container and draining the excess amount of lubricating liquid will be required before filling the contents. In other words, a method using spraying cannot be adopted in terms of wasting lubricating liquid and the existence of unnecessary processes.

[0011] The inventors previously proposed a package in which the entire inner surface of the container body is uneven, and the uneven surface is covered with a lubricating liquid (PCT / JP2016 / 076260). This package is characterized in that the lubricating liquid is retained by the uneven surface, and when the container is held upright, a pool of the lubricating liquid is formed around the periphery of the upper surface of the fluid contained in the container body. In this package, the lubricating liquid provides stable slippage for the fluid, allowing it to be quickly discharged, and it can be easily manufactured without increasing costs. As a result of further investigation into such packages, the inventors discovered the extremely surprising finding that, when there is a certain relationship between the wettability and other properties of the fluid contained within the container body and the wettability and other properties of the lubricating liquid coating the inner surface of the container body, the ease with which the fluid can be discharged from the container body can be significantly improved even if the inner surface of the container body is not roughened. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-254377 [Patent Document 2] Patent No. 4878650 [Patent Document 3] Special Publication No. 2015-510857 [Patent Document 4] Patent No. 5673870 Summary of the Invention [Problem to be solved by the invention]

[0013] Therefore, the object of the present invention is to provide a method for discharging a fluid from a package which comprises a container body containing a fluid, the inner surface of which is coated with a lubricating liquid, has extremely high fluid discharge properties, and can be easily manufactured without increasing costs. [Means for solving the problem]

[0014] That is, according to the present invention, there is provided a method for discharging a fluid from a package consisting of a container body in which the fluid is contained, so as to leave a head space, wherein a lubricant that is immiscible with the fluid is supplied to the inner surface of the container body, thereby forming a coating layer on the inner surface, and when the container body is held upright, the lubricant in the coating layer drips down from the part corresponding to the head space, thereby forming a pool of lubricating liquid around the periphery of the upper end of the fluid, and this pool causes the fluid to separate from the container body, thereby discharging the fluid from the container body.

[0015] In the method for discharging a fluid of the present invention, the fluid is preferably a viscous substance having a viscosity of 100 mPa·s (25° C.) or more. [Effects of the Invention]

[0016] The first feature of the package of the present invention is that, when the container body is in an upright position, a pool of lubricating liquid is formed around the periphery of the upper surface of the fluid contained in the container body. In other words, because this pool of lubricating liquid is formed around the upper periphery of the fluid, when the container body is tilted to dispense the fluid, the fluid is always in contact with the lubricating liquid when dispensed. Moreover, in the present invention, a coating layer of lubricating liquid is formed on the inner surface of the container body. As a result, in the package of the present invention, the lubricating liquid in contact with the fluid behaves as one with the fluid, and when the container body is returned to its upright position, the lubricating liquid flows back along the inner surface of the container body together with the fluid, remaining in the container body in contact with the fluid that has not been dispensed. Thus, according to the present invention, stable slipperiness is always exhibited even when the fluid (contents) is repeatedly discharged.

[0017] Furthermore, the above-mentioned pool of lubricating liquid is formed by the lubricating liquid that covers the inner surface (smooth surface) of the headspace portion falling down. As can be understood from this, the layer of lubricating liquid that covers the inner surface of the container body can be formed by spraying an excess amount of lubricating liquid onto the inner surface of the container body after the contents have been filled. That is, there is no need to employ a method such as adding a surface-roughening agent to a resin to form irregularities on the inner surface of the container, or forming irregularities on the inner surface of the container by post-processing. A coating layer of lubricating liquid can be formed by the simple method of spraying lubricating liquid onto the inner surface of the container body. This allows a package to be obtained that stably exhibits the properties of the lubricating liquid without using complicated and costly methods such as uniforming the degree of irregularities.

[0018] Furthermore, a second feature of the present invention is that the contact angle of the lubricating liquid with respect to the inner surface is smaller than the contact angle of the fluid with respect to the inner surface. That is, in the present invention, the liquid pool as described above is formed, and at the same time, the fluid contained in the container body and the lubricating liquid coating the inner surface of the container body are selected so as to satisfy the above-mentioned relationship, so that when the container body is tilted to discharge the fluid, the fluid quickly peels off and falls from the inner surface located at the upper side of the tilted container body. In other words, the peelability of the fluid is improved, and, combined with the above-mentioned slipperiness, it is possible to achieve significantly excellent dischargeability.

[0019] The package of the present invention can stably improve the slipperiness of fluids by selecting and using an appropriate lubricating liquid that satisfies the above relationship depending on the type of fluid contained in the container body, and is therefore particularly suitable for containing viscous liquids, such as viscous substances with a viscosity of 100 mPa·s (25°C) or more (ketchup, mayonnaise, dressing, etc.). [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a schematic cross-sectional view (bottom (sliding side)) showing the main parts of the package of the present invention and the state when discharging a fluid. [Figure 2] 1 is a schematic cross-sectional view (upper portion (peeling side)) showing the main parts of the package of the present invention and the state when discharging a fluid material. [Figure 3] FIG. 1 is a diagram showing the overall shape of a direct-blow bottle, which is the most suitable shape of the container body in the package of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] <Package structure and function> Referring to Figures 1 and 2, the package of the present invention consists of a container body 1 containing a fluid 3 inside, and as shown in Figures 1(A) and 2(A) in particular, when in an upright position, the upper end of the container body 1 is sealed with a sealing foil 5 and is appropriately closed with a lid (not shown), and a headspace 7 is formed between the upper surface of the fluid 3 and the upper end of the container body 1 (sealing foil 5).

[0022] A suitable example of the container body 1 as described above is a direct blown bottle, the configuration of which is shown in FIG. In Figure 3, the direct-blow bottle (corresponding to the container body 1 in Figures 1 and 2) generally designated 10 has a neck 11 equipped with a thread, a body wall 15 connected to the neck 11 via a shoulder 13, and a bottom wall 17 closing the lower end of the body wall 15. After filling the bottle with the fluid 3 (not shown in Figure 3), the opening at the upper end is closed with a sealing member 19 (corresponding to the sealing foil 5 in Figure 1) such as aluminum foil, and a cap 20 is screwed on to ensure sealing. The bottle 10 is suitable for use in containing viscous fluids, and the viscous substance contained therein is expelled by squeezing the body wall 15.

[0023] 1 and 2, the inner surface 1a of the container body 1 (for example, the direct-blow bottle 10 in FIG. 3) may be a rough surface or a smooth surface. In the example shown in the figure, it is shown as a smooth surface. Such a smooth surface 1a is coated with a lubricating liquid 30 that improves the slipperiness of the fluid 3, and the lubricating liquid 30 is interposed between the fluid 3 and the inner surface 1a of the container body 1. In the present invention, the lubricating liquid 30 and the fluid 3 are selected so that the contact angle of the lubricating liquid 30 with the inner surface 1a is smaller than the contact angle of the fluid 3 with the inner surface 1a.

[0024] In the package of the present invention having the basic structure described above, as shown in Figures 1(A) and 2(A), when the container body 1 is in an upright position, a pool 31 of lubricating liquid 30 is formed around the periphery of the upper surface of the fluid 3. That is, in the upright position, the lubricating liquid 30 covering the inner surface 1a of the head space 7 portion located above the fluid 3 flows down, forming the pool 31 of lubricating liquid 30. Therefore, the thickness of the lubricating liquid 30 covering the inner surface 1a' located in the head space 7 portion is thinner than the thickness of the lubricating liquid 30 in the portion sandwiched between the fluid 30 and the container inner surface 1a. In the present invention, the liquid pool 31 formed as described above provides stable and excellent slipperiness when the fluid 3 is discharged.

[0025] For example, to discharge the fluid 3, as shown in Fig. 1(B), after peeling off the sealing foil 5, the container body 1 is tilted, causing the lubricating liquid 30 forming the liquid pool 31 to flow down along the inner surface 1a (1a') of the head space 7 portion to the upper end portion of the container body 1. When the fluid 3 is discharged in this state, as shown in Fig. 1(C), the lubricating liquid 30 forming the liquid pool 31 flows down, forming a thin film 30a of the lubricating liquid 30 on the inner surface 1a' of the portion corresponding to the head space 7. The fluid 3 is discharged together with part of the lubricating liquid 30 while in contact with this thin film 30a of the lubricating liquid 30, or slides on the thin film 30a of the lubricating liquid 30, thereby exhibiting stable and excellent slipperiness. Furthermore, when the container body 1 is returned to an upright position after a certain amount of fluid 3 has been discharged, the lubricating liquid 30 experiences small flow resistance, so it quickly flows down into the container body 1, and the fluid 3 that has not been discharged quickly falls into the container body 1 together with the lubricating liquid 30. Furthermore, if the container body 1 is kept upright after the fluid 3 has been discharged, the lubricating liquid 30 in the head space 7 will gradually fall over time, and a liquid pool 31 will again form around the periphery of the upper end surface of the fluid 3, as shown in Figure 1(A).The next time the fluid 3 is discharged, it can be discharged as quickly as it was initially.

[0026] In such a package of the present invention, the contact angle of the lubricating liquid 30 with the inner surface 1a of the container body 1, which serves as the base, is smaller than the contact angle of the fluid with the inner surface 1a, and the flow resistance of the lubricating liquid 30 is extremely small. Therefore, the fluid 3 contained in the container body 1 can be quickly discharged from the container body 1 together with the lubricating liquid 30, and even if the fluid is a viscous substance, it can be discharged without remaining in the container body 1.

[0027] On the other hand, when the container body 1 is tilted to dispense the fluid 3, the behavior of the side where the fluid 3 and the container body 1 separate (i.e., the upper side of the inner surface 1a of the container body 1) is examined. As shown in FIG. 2(B), gravity acts first in a direction that moves the fluid 3 away from the container body 1. At this time, the liquid pool 31 acts as a force that causes it to flow down along the inner surface 1a toward the upper end of the container body 1 due to the tilt. At the same time, the liquid pool 31 also tries to flow onto the inner surface 1a to fill the gap created by the movement of the fluid 3. As a result, as shown in FIG. 2(C), the lubricating liquid 30 penetrates between the fluid 3 and the container body 1, and the fluid 3 and the container body 1 easily separate. When the liquid pool 31 is small or absent, the fluid 3 does not flow between the container body 1 and the fluid 3 as described above, and the separation ability is significantly reduced.

[0028] As explained in Figs. 1 and 2, the formation of a lubricating liquid pool results in a synergistic effect of improved slipperiness and releasability, enabling stable and excellent discharge.

[0029] <Container body 1> In the present invention, the inner surface 1a of the container body 1 described above is shown as a smooth surface, but it may be a rough surface as long as the above-mentioned behavior is not hindered.

[0030] The material for forming the inner surface 1a of the container body 1 is not particularly limited, and can be selected and used depending on the application and contents, such as thermoplastic resin, thermosetting resin, glass, metal, etc., but it is preferable that it be formed from a thermoplastic resin in order to prevent excessive consumption of the lubricating liquid 30. The thermoplastic resin is not particularly limited as long as it can be molded into the shape of a container, but generally, olefin resins such as low-density polyethylene, linear low-density polyethylene, medium- or high-density polyethylene, polypropylene, poly-1-butene, and poly-4-methyl-1-pentene, copolymer resins of these olefins, and polyester resins such as polyethylene terephthalate, polyethylene naphthalate, and polyethylene terephthalate / isophthalate are preferred, and these are also suitable for forming the outer surface of a container. In particular, when this container body 1 is used as a direct blow bottle as shown in Figure 3, it is preferable to use an olefin-based resin such as low-density polyethylene or linear low-density polyethylene, as these resins are suitable for squeezing out the contents.

[0031] Furthermore, since the inner surface 1a of the container body 1 formed from the above-mentioned thermoplastic resin does not need to be a rough surface, this thermoplastic resin does not need to contain inorganic materials that function as roughening agents, but this inner surface 1a may be formed from a rough surface and a smooth surface. When tilting the container to discharge the fluid, in order to encourage the fluid to start moving, the surface that exhibits slipperiness can be made rough and the surface that exhibits release properties can be made smooth, i.e., the lower surface can be made rough and the surface opposite the lower can be made smooth, The roughened surface may be formed by blending inorganic materials such as silica, which function as a roughening agent, into the inner resin. The particles to be blended are not particularly limited as long as their average particle size is within the above-mentioned range. Typical examples include metal oxide particles such as titanium oxide, alumina, and silica; carbonates such as calcium carbonate; carbon-based particles such as carbon black; and organic particles such as polymethyl (meth)acrylate, polyethylene, and silicone particles typified by polyorganosilsesquioxane. These may be hydrophobized with a silane coupling agent or silicone oil. Since the present invention can also be carried out by extrusion molding, typified by direct blow molding, any particles that maintain their particle size after melt molding are suitable. For example, hydrophobized fine particles, particularly hydrophobic silica, cured polymethyl methacrylate, ultrahigh molecular weight polyethylene, polyorganosilsesquioxane, and silicone particles are suitable.

[0032] Furthermore, in the present invention, the container body 1 may have a single layer structure of the above-mentioned thermoplastic resin, or may have a multi-layer structure.

[0033] For example, a gas barrier resin layer may be formed as an intermediate layer between the inner and outer layers of the container body 1, thereby preventing deterioration of the contents 3 due to permeation of gases such as oxygen.

[0034] Representative examples of the gas barrier resins mentioned above include ethylene-vinyl alcohol copolymers (saponified ethylene-vinyl acetate copolymers), aromatic polyamides, and cyclic polyolefins, of which ethylene-vinyl alcohol copolymers are the most suitable because they exhibit particularly excellent oxygen barrier properties. As the ethylene-vinyl alcohol copolymer, a saponified copolymer obtained by saponifying an ethylene-vinyl acetate copolymer having an ethylene content of 20 to 60 mol %, particularly 25 to 50 mol %, to a degree of saponification of 96 mol % or more, particularly 99 mol % or more is generally suitable. The above-mentioned gas barrier resins may be used alone or in a blend of two or more. Furthermore, in order to improve adhesion to the inner and outer layers, a polyolefin such as polyethylene may be blended into the gas barrier resin, as long as the gas barrier properties are not impaired.

[0035] Furthermore, when the gas barrier resin layer as described above is provided as an intermediate layer, it is preferable to provide an adhesive resin layer between the inner or outer layer and the gas barrier resin layer in order to improve adhesion to these layers and prevent delamination. The adhesive resins used to form such adhesive resin layers are known per se, and examples of adhesive resins that can be used include resins containing carbonyl groups (>C=O) in the main chain or side chain in an amount of 1 to 100 meq / 100 g of resin, particularly 10 to 100 meq / 100 g of resin, specifically olefin resins graft-modified with carboxylic acids such as maleic acid, itaconic acid, and fumaric acid, or their anhydrides, amides, and esters; ethylene-acrylic acid copolymers; ionically cross-linked olefin copolymers; and ethylene-vinyl acetate copolymers.

[0036] Furthermore, in the multi-layer structure as described above, scrap resin such as burrs generated when molding the container body 1 can be mixed with virgin resin for forming the inner or outer layer to form a repro layer.

[0037] Each of the above-mentioned layers is set to a known thickness so that the layer exhibits the required properties. The resin for forming each layer may also contain additives such as antioxidants, surfactants, and colorants, as long as the additives do not impair the properties of the layer.

[0038] The container body 1 may have various shapes, for example, a bottle or a cup, as long as it can form a liquid pool 31 when the inner surface 1a is covered with the lubricating liquid 30. Such a container body 1 is manufactured by forming a preform by extrusion molding using the resins that form each of the layers described above, and then shaping it into the desired container shape by post-processing such as blow molding, plug-assist molding, vacuum molding, etc. In particular, in the present invention, it is optimal for this container body 1 to have the form of a direct blown bottle suitable for discharging viscous fluids, as shown in Fig. 3. Such a direct blown bottle is produced by molding a tubular preform by extrusion molding, pinching off one end of this preform to close it, and then blowing a blowing fluid such as air into the preform to shape it into a bottle.

[0039] <Lubricant 30 and Fluid 3> In the package of the present invention, which consists of a container body 1 containing a fluid 3 as described above, the inner surface 1a of the container body 1 obtained as described above is coated with lubricating liquid 30, and then the fluid 3 is filled so that a headspace 7 is formed.

[0040] The lubricating liquid 30 used has appropriate surface properties depending on the type of fluid 3 filled in the container body 1, but it is of course necessary for the lubricating liquid 30 to be immiscible with the fluid 3. In the present invention, being immiscible with the fluid 3 means that the lubricating liquid 30 does not immediately undergo molecular dispersion upon contact with the fluid 3 but remains as the lubricating liquid 30. Furthermore, the lubricating liquid must be a non-volatile liquid with a low vapor pressure under atmospheric pressure, for example, a high-boiling liquid with a boiling point of 200°C or higher. If a volatile liquid is used, it will easily volatilize and disappear over time, making it difficult to improve the lubricity of the fluid 3.

[0041] Specific examples of such lubricating liquid 30 include various types, provided that they are high-boiling point liquids as described above and that their contact angle with the inner surface 1a is smaller than the contact angle with the inner surface 1a of the fluid 3. In particular, the more the surface tension of the lubricating liquid is different from that of the fluid 3 that is the target for slipperiness, the higher the lubricating effect and the more suitable it is for the present invention. For example, when the fluid 3 is water or a hydrophilic substance containing water, it is preferable to use a liquid having a surface tension in the range of 10 to 40 mN / m, particularly 16 to 35 mN / m, as the lubricating liquid 30. Representative examples of such liquids include fluorine-based liquids, fluorine-based surfactants, silicone oils, fatty acid triglycerides, and various vegetable oils. Suitable vegetable oils include soybean oil, rapeseed oil, olive oil, rice bran oil, corn oil, safflower oil, sesame oil, palm oil, castor oil, avocado oil, coconut oil, almond oil, walnut oil, hazelnut oil, and salad oil. Blends of the above liquids may also be used. Furthermore, it is preferable that the lubricating liquid selected from the above has high wettability with respect to the inner surface 1a (has a small contact angle with respect to the inner surface 1a), and the lubricating liquid that forms the liquid reservoir 31 may be different from the lubricating liquid that coats the inner surface 1a. The term "contact angle" as used herein refers to the angle formed by the liquid surface and the solid surface at the boundary line where the three phases contact when the inner surface of the solid is in contact with the liquid and gas.

[0042] In the present invention, it is important that a certain amount of excess lubricating liquid 30 is contained in order to form a coating layer of lubricating liquid 30 on the inner surface 1a and to form the liquid pool 31. The excess lubricating liquid may be added after or before filling the container with the fluid. Methods for adding the lubricating liquid include spraying, extruding simultaneously with the molten resin, ejecting simultaneously with the contents, and bleeding by adding the lubricating liquid into the resin. In particular, when the type of lubricating liquid coating the inner surface 1a of the container body 1 and the type of lubricating liquid forming the liquid pool 31 are different, the lubricating liquid forming the liquid pool 31 will be applied later as an excess. That is, in the present invention, the inner surface 1a of the container body 1 is coated with the above-mentioned lubricating liquid 30, and such coating is achieved by applying an excess amount of lubricating liquid 30 to the inner surface 11a of the container body 1 so that when the fluid 3 is filled, a liquid pool 31 is formed on the peripheral portion of the fluid 3 facing the head space 7 (see Figure 1 (A)). That is, as shown in FIG. 1(A), when the container body 1 filled with the fluid 3 is held upright, the entire inner surface 1a is covered with excess lubricating liquid 30 so that the lubricating liquid 30 drips from the inner surface 1a (1a') facing the head space 7, or in some cases, excess lubricating liquid is supplied after filling with the fluid.

[0043] For this purpose, it is necessary to apply the lubricating liquid 30 to the entire inner surface of the container body 1 by spraying. For example, the amount of application, including excess, is 0.1 g / m on average. 2 Above 0.1 to 10 g / m 2 By applying such an amount, the smooth surface 1 a is completely covered with the lubricating liquid 30. Therefore, as long as the liquid pool 31 is formed, the inner surface 1a may be a rough surface.

[0044] Furthermore, as long as an excess amount of lubricating liquid 30 can cover the entire inner surface 1a, the spraying of lubricating liquid 30 may be performed while the container body 1 is held upright or inverted.

[0045] After the lubricating liquid 30 has been applied as described above, the fluid 3 is supplied from a predetermined filling pipe into the container body 1, which is held upright and whose entire inner surface is covered with excess lubricating liquid 30, so as to leave a head space 7. (In some cases, excess lubricating liquid 3 is supplied after filling the container body with the fluid 3.)

[0046] That is, when the fluid 3 is filled as described above, the lubricating liquid 30 covering the inner surface 1a (1a') of the portion corresponding to the head space 7 drips down, and a liquid pool 31 can be formed on the peripheral portion of the upper end surface of the fluid 3. Therefore, as shown in Figure 1(A), the thickness of the lubricating liquid 30 above the liquid pool 31 is thinner than the thickness of the lubricating liquid 30 existing between the side surface of the fluid 3 and the smooth surface 1a, as described above.

[0047] As mentioned above, the fluid 3 filled as described above has a surface tension significantly different from that of the lubricating liquid 30 (its contact angle with the inner surface 1a is larger than that of the lubricating liquid 30), and is particularly a viscous fluid with a viscosity (25°C) of 100 mPa·s or more, specifically ketchup, water-based glue, honey, various sauces, mayonnaise, mustard, dressing, jam, chocolate syrup, cosmetic liquids such as lotion, liquid detergent, shampoo, conditioner, etc. In other words, by forming a liquid pool 31 using an appropriate lubricating liquid 30 depending on the type of fluid 3, these viscous fluids 3 can be quickly discharged by tilting or turning the container upside down. For example, ketchup, various sauces, honey, mayonnaise, mustard, jam, chocolate syrup, and emulsion are hydrophilic substances that contain water, and the lubricating liquid 30 is preferably selected from oily liquids approved as food additives, such as silicone oil, glycerin fatty acid esters, and edible oils.

[0048] After filling the container with the fluid 3 while leaving the head space 7 and forming the reservoir 31 of the lubricating liquid 30 as described above, the sealing foil 5 is applied by heat sealing, and a lid is attached as appropriate to obtain the package of the present invention. [Example]

[0049] The invention is illustrated in the following examples. The methods for measuring various characteristics and physical properties and the container body (bottle) used in the following examples are as follows:

[0050] <Container body> A multi-layered direct blown bottle having the following layer structure and a capacity of approximately 500 mL was molded by a known method and used in the following experiments. Bottle A: 5 types, 9 layers, direct blown multi-layer bottle Layer composition: Inner layer / adhesive layer / liquid diffusion suppression layer / adhesive layer / main layer / adhesive layer / oxygen barrier layer / adhesive layer / outer layer Inner layer: low density polyethylene Adhesive layer: Acid-modified polyethylene Liquid diffusion suppression layer: Ethylene-vinyl alcohol copolymer (EVOH) Main layer: Low-density polyethylene (LDPE) Oxygen barrier layer: Ethylene-vinyl alcohol copolymer (EVOH) Outer layer: Low-density polyethylene (LDPE) Bottle B: 5 types, 9 layers, direct blown multi-layer bottle B Layer composition: Inner layer / adhesive layer / liquid diffusion suppression layer / adhesive layer / main layer / adhesive layer / oxygen barrier layer / adhesive layer / outer layer Inner layer: Low-density polyethylene containing 5% by weight of silica with an average particle size of 5 μm Adhesive layer: Acid-modified polyethylene Liquid diffusion suppression layer: Ethylene-vinyl alcohol copolymer (EVOH) Main layer: Low-density polyethylene (LDPE) Oxygen barrier layer: Ethylene-vinyl alcohol copolymer (EVOH) Outer layer: Low-density polyethylene (LDPE)

[0051] <Lubricant> Medium Chain Triglycerides (MCTs) Surface tension: 28.8mN / m (23℃) Viscosity: 33.8mPa·s (23℃) Boiling point: 210°C or higher Flash point: 242°C (reference value) The surface tension of the liquid was measured at 23°C using a solid-liquid interface analysis system, DropMaster 700 (Kyowa Interface Science Co., Ltd.). The density of the liquid, required for measuring the surface tension, was measured at 23°C using a density and specific gravity meter, DA-130 (Kyoto Electronics Manufacturing Co., Ltd.). The viscosity of the lubricating liquid was measured at 23°C using a tuning fork vibration viscometer, SV-10 (A&D Co., Ltd.).

[0052] <Flowing object> Mayonnaise-like consistency food Viscosity: 499Pa·s(0.1sec -1 ), 94 Pa·s (1 sec -1 ), 0.30 Pa·s (1000 sec -1 ). The viscosity was measured using a rheometer (ARES, manufactured by TA Instruments) with a parallel plate geometry and a gap of 0.5 mm using the steady flow method.

[0053] <Creating a lubricant pool> 200 g of the fluid was filled into the bottle, and a few drops of lubricating liquid (MCT) were dropped on the periphery of the upper surface of the fluid to create a liquid pool. In addition, for the peelability test described later, lubricating liquid (MCT) was dropped only on a part of the periphery (approximately 1 / 4 of the periphery) to create a localized liquid pool.

[0054] <Slipperiness test for fluids> After creating a puddle of lubricating liquid, the bottle was tilted at an angle of approximately 45° from an upright position at room temperature (25°C), and the slipperiness of the contents was evaluated based on the time it took for the contents to completely slide down the neck of the bottle. The evaluation criteria were as follows: ○: Time to slide down is less than 5 minutes. △: Time to slide down is between 5 and 10 minutes. ×: It takes more than 10 minutes to slide down the slope. <Removal test for fluids> Using a bottle with a localized liquid pool created using the method described above, the bottle was tilted at about 45° from an upright position at room temperature (25°C) so that the liquid pool was on top, and the degree of peeling of the contents was evaluated. The evaluation criteria were as follows: ○: Peels off instantly. ×: No peeling or peeling time is 10 minutes or more.

[0055] <Experimental Example 1> Bottle A (a 5-type, 9-layer, direct-blown multilayer bottle) was prepared as the container body. A lubricating liquid, medium-chain triglyceride, was applied to the inner surface of Bottle A using an airbrush by air spraying in the amount shown in Table 1. Using the bottle with the lubricating liquid applied to the inner surface, the aforementioned puddles of lubricating liquid were created, and the fluid slipperiness test and the fluid peelability test were carried out. The results are summarized in Table 1. The contact angle of the lubricating liquid with the low-density polyethylene surface was smaller than that of the fluid.

[0056] <Experimental Example 2> Except for not creating a puddle of lubricating liquid, the fluid slippage test and fluid peeling test were carried out in the same manner as in Experimental Example 1. The results are shown in Table 1.

[0057] <Experimental Example 3> Bottle B (a 5-type, 9-layer, direct-blown multilayer bottle) was prepared in the same manner as in Experimental Example 1, except that low-density polyethylene containing 5% by weight of silica with an average particle size of 5 μm was used as the resin for the inner layer. The bottle was evaluated in the same manner as above, and the results are shown in Table 1.

[0058] <Experimental Example 4> The fluid slipperiness test and fluid peelability test were conducted in the same manner as in Experimental Example 1, except that no medium-chain fatty acid triglyceride was applied as a lubricant to the inner surface of Bottle A by air spraying using an airbrush, and no puddle of lubricant was created. The results are summarized in Table 1.

[0059] [Table 1]

[0060] Table 1 shows that in Experimental Examples 1 to 3, in which the inner surface of the bottle was coated with lubricating liquid, Experimental Examples 1 and 3, in which a puddle of lubricating liquid was created, had good slip properties and releasability, while Experimental Example 2, in which a puddle of lubricating liquid was not created, had poor properties. Moreover, in Experimental Example 4, in which no liquid film was applied and no liquid pool was created, both the slipperiness and peelability were poor. From the above, by coating the container with a liquid film and creating a liquid pool, both the slipperiness and peelability are improved, and the synergistic effect makes it possible to easily discharge the contents. [Explanation of symbols]

[0061] 1: Container body 1a: inner surface of container body 1 3: Flowing animal 5: Seal foil 7. Headspace 30: Lubricant 31: Liquid puddle

Claims

1. A method for discharging a fluid from a package comprising a container body containing the fluid so as to leave a head space, comprising: A lubricant that is immiscible with the fluid is supplied to the inner surface of the container body to form a coating layer on the inner surface, and When the container body is held upright, the lubricant in the coating layer drips down from the portion corresponding to the head space, forming a pool of lubricating liquid around the periphery of the upper end of the fluid; A method for discharging a fluid, comprising: causing the fluid to separate from the container body by the liquid pool, thereby discharging the fluid from the container body.

2. 2. A method for discharging a fluid according to claim 1, wherein the fluid is a viscous substance having a viscosity of 100 mPa·s (25° C.) or more.

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