WO2010029968A1

WO2010029968A1 - Hot-filled package and process for producing the package

Info

Publication number: WO2010029968A1
Application number: PCT/JP2009/065828
Authority: WO
Inventors: 洋介阿久津; 淳菊地
Original assignee: 東洋製罐株式会社
Priority date: 2008-09-12
Filing date: 2009-09-10
Publication date: 2010-03-18
Also published as: JP5343972B2; JPWO2010029968A1

Abstract

A hot-filled package is provided which contains a filling hot-packed therein and which, despite this, has been remarkably improved in such a property that the filling falls off the container in an upended state. The package comprises: a polyolefin container having, formed on the inner surface thereof, an olefin resin layer containing a lubricant ingredient comprising amphipathic molecules; and a filling hot-packed therein. The package is characterized in that when the hot-packed filling is taken out thereof and the inner surface of the container is examined by X-ray diffractometry by the reflection method, then the inner surface gives an X-ray profile which has a peak attributable to the multi-molecular layer structure of the lubricant formed on the inner surface of the container.

Description

Hot-filled package and method for producing the package

The present invention relates to a hot-filled package, and more particularly to a hot-filled package in which a non-oil content is hot-filled and a method for manufacturing the package.

Plastic containers are widely used for various applications because they are easy to mold and can be manufactured at low cost. For example, containers in which the inner surface of the container wall is formed of an olefin-based resin layer such as polyethylene are not suitable. It is also used as a container for containing a thick slurry-like or paste-like content.

By the way, in the plastic container for storing the viscous contents, in order to quickly discharge the viscous contents filled in the container, or to use it cleanly without remaining in the container. In many cases, the container is stored in an inverted state. Therefore, when the container is inverted, the contents do not remain attached to the inner wall surface of the container, and for example, a characteristic that the viscous contents quickly fall is desired.

Various proposals have been made for plastic containers in which the contents are prevented from adhering to the inner wall surface of the container. For example, Patent Document 1 uses shampoos and liquid detergents mainly composed of surfactants. It has been proposed that a multi-layer polyethylene container is blended with 4000 ppm or more of erucamide or 1 to 5% by weight of silicone oil as an anti-adhesion agent on the inner surface of the container.

As can be understood from the proposal by the above-mentioned Patent Document 1, many studies have been conducted on the shampoo and the liquid detergent so that the contents do not adhere to the container wall surface and almost the entire contents can be quickly discharged out of the container. For example, non-oily substances such as ketchup that are viscous but have no stickiness due to oil are not well studied. For example, Patent Document 2 proposes adding two or more fatty acid amides to a resin layer made of polyolefin for an olefin resin bottle filled with food such as ketchup or mayonnaise. By adding two types of fatty acid amide to the outer surface layer of the container, the bottle is made slippery to improve the blocking resistance of the bottle, and the bottle-to-bottle contact and other parts in the bottle production line It is intended to prevent inconvenience due to contact with the container, and not to prevent the contents from adhering to the inner wall surface of the container.

JP-A-6-99481 Japanese Patent No. 2627127

By the way, the applicant previously filed a patent application for a polyethylene container in which a polyethylene resin layer to which an aliphatic amide, in particular an unsaturated aliphatic amide such as oleic acid amide was added, was formed on the inner surface of the container. Has already been patented (Patent No. 4218729). This polyethylene container is superior in the inverted fall of the contents against non-oily viscous contents such as ketchup, but the contents are hot filled only by adding aliphatic amide. Inverted fallability of the contents will be reduced when added, and organic peroxides are added together to maintain the inverted fallability of the contents at a high level even when the contents are hot filled. That's it.

However, the use of unstable compounds such as organic peroxides is not only difficult to handle but also increases costs, so it is desirable to avoid using them if possible.

In addition, as a means for improving the inverted fallability of the contents, it is usually considered that a lubricant is blended into the olefin resin layer on the inner surface of the container. In the formulation of lubricant, even if the contents can be improved to some extent when the contents are filled in the container at room temperature, the contents are inverted when the contents are hot filled. It was found that the dropability could not be improved sufficiently.

Therefore, an object of the present invention is to provide a hot-filled package and a method of manufacturing the package, in which the inverted fallability of the contents is remarkably improved regardless of whether the contents are hot-filled.

As a result of many experiments conducted on a polyolefin container having an olefin-based resin layer containing a lubricant component on the inner surface of the container, the present inventors have found that a lubricant component composed of an amphiphilic molecule is contained. X is obtained when X-ray diffraction measurement is performed by a reflection method on the inner surface of the container in a state in which the polyolefin container is hot-filled with the contents and the hot-filled contents are taken out. In the line profile, when a peak derived from the lubricant multi-layer structure formed on the inner surface of the container is expressed, the slipperiness by the lubricant can be secured stably, and the contents are hot-filled. In spite of this, the present inventors completed the present invention by obtaining a very interesting new finding that the inverted fallability of the contents is greatly improved.

That is, according to the present invention, there is provided a package in which contents are hot-filled in a polyolefin container in which an olefin resin layer containing a lubricant component composed of an amphiphilic molecule is formed on the inner surface. In a package in which the contents are hot-filled in a polyolefin container in which an olefin-based resin layer containing a lubricant component made of a functional molecule is formed on the inner surface, the container is in a state where the hot-filled contents are taken out. When X-ray diffraction measurement is performed on the inner surface by a reflection method, the resulting X-ray profile has a peak derived from a lubricant multi-layer structure formed on the inner surface of the container. A hot-filled polyolefin package is provided.

The hot-fill package of the present invention is particularly
(1) In the X-ray profile, a primary peak derived from a lubricant multilayer structure formed on the inner surface of the container and a secondary peak derived from the multilayer structure are expressed.
(2) The primary peak and the secondary peak expressed in the X-ray profile have a peak intensity ratio (secondary peak / primary peak) of 0.12 or more,
(3) The olefin resin layer formed on the inner surface of the container contains the lubricant component in an amount of 0.05 to 0.5 parts by weight with respect to 100 parts by weight of the olefin resin.
(4) The olefin-based resin layer contains a fatty acid amide having a melting point of 85 ° C. or higher as a lubricant component.
(5) the fatty acid amide is a saturated fatty acid amide;
(6) The olefin resin is a polyethylene resin,
(7) The polyolefin container has a multilayer structure having the olefin resin as an innermost layer,
(8) The hot-filled contents are non-oily substances,
Is preferred.

According to the present invention, there is also provided a method for producing a package in which the contents are hot-filled in a polyolefin container in which an olefin resin layer containing a lubricant component composed of amphiphilic molecules is formed on the inner surface. A method for producing a hot-filled package is provided, wherein after the container is formed, at least the inner surface of the container is subjected to heat treatment by non-contact heating, and then the contents are hot-filled.
Note that non-contact heating means heating without applying pressure to the inner surface of the container to be heated. For example, oven heating in which heating is performed by holding the container in a heated atmosphere under non-pressurization, or induction Means heating. For example, when the contents are hot-filled, the inner surface of the container is heated, but such heating is not included in the non-contact heating because the pressure by the contents is applied to the inner surface of the container.

In the production method of the present invention, in particular,
(1) performing the heat treatment at 70 to 110 ° C. for 1/6 to 10 minutes;
(2) When the temperature of the heat treatment is T ° C. and the heat treatment time is t minutes, the following formula:
45 ≦ T · t ≦ 1100
Heat treatment to satisfy the conditions of
(3) performing the hot filling at a temperature of 60 ° C. or higher;
Is preferred.

When the X-ray diffraction measurement by the reflection method is performed on the inner surface of the container with the hot-filled contents taken out, the obtained X-ray profile is obtained on the inner surface of the container. A peak derived from the lubricant multi-layer structure formed in FIG. The primary peak in this X-ray profile is derived from diffraction from the plane spacing of one layer of the lubricant multilayer structure.
As a result, when the contents fall along the inner surface of the container, even if some of the lubricant molecules in the upper layer fall off, there is an regularly arranged layer underneath, so that the excellent inverted fall continues. Showing gender.

In addition, it is preferable that the peak expresses a first order peak and a second order peak derived from high-order diffraction with a plane spacing of one layer of the multi-layer structure. The presence of the peak indicates that the multilayer structure is stably formed.

Further, it is most preferable that the primary peak and the secondary peak expressed in the X-ray profile have a peak intensity ratio (secondary peak / primary peak) of 0.12 or more, The strength ratio indicates that a large amount of lubricant molecules are regularly arranged on the inner surface of the container, and a more excellent inverted fall property is exhibited.

According to the method for producing a hot-filled package of the present invention, the inner surface of the polyolefin container is heat-treated by non-contact heating before hot filling, so that a multi-molecular layer of a lubricant regularly arranged on the inner surface of the container is formed. The content of the slipperiness imparting effect by the lubricant is stably exhibited, the inverted fallability to the hot-filled contents such as ketchup is remarkably improved, and when the packaging body is held upside down, the contents However, it is possible to manufacture a hot-filled packaging body that does not remain on the inner surface of the container and falls quickly.

Explanatory drawing for demonstrating the presence form of the lubricant (amphiphilic molecule) bleeding on the container inner surface. The figure which shows the X-ray profile about the package manufactured in Example 6. FIG. The figure which shows the X-ray profile about the package body manufactured by the comparative example 2. FIG.

<Hot-fill packaging>
The hot-filled package according to the present invention exhibits a specific X-ray profile because a multi-molecular multilayer structure in which the lubricant components bleeding on the inner surface of the container are arranged in a highly ordered and orderly manner is formed.
That is, when the X-ray diffraction measurement by the reflection method is performed on the inner surface of the container in which no lubricant component is blended, no peak appears in the X-ray profile. The peak expressed in the X-ray profile is considered to be due to the lubricant multi-molecular layer bleeding on the inner surface of the container. In addition, the high-intensity primary peak is derived from diffraction from the plane spacing of one layer of the multi-layer structure that is present in the largest amount, and the secondary peak is a high-order next time plane spacing of one layer of the multi-layer structure. It is presumed that the highly ordered polymolecular multilayer structure as shown in FIG. 1 (a) is formed.

As understood from the experimental results of Examples described later, the contents were taken out from the hot-filled package, and the inner surface of the container was washed with water, and then the X-ray diffraction measurement was performed on the inner surface of the container by a reflection method. In the X-ray profile sometimes obtained, a peak derived from a lubricant multi-layer structure formed on the inner surface of the container appears (for example, see FIG. 2).

That is, this peak is a large peak (primary peak) that appears around 2.6 °. From the Bragg equation (nλ = 2dsinθ), this peak indicates that a structure of about 3.4 nm exists in the direction perpendicular to the inner surface of the container. Here, considering that the size of one molecule of stearamide is about 2.2 nm, it can be said that stearamide forms a bilayer membrane structure with adjacent amide molecules. That is, this peak is derived from diffraction from the plane spacing of one layer of the lubricant multilayer structure formed on the inner surface of the container. The presence of such a primary peak indicates that a multi-molecular layer of lubricant is present on the inner surface of the container.

In the X-ray profile, a small secondary peak appears around 7.6 °. This peak corresponds to d = 1.1 nm, and can be said to be derived from high-order diffraction that is an integral multiple (here, 3 times) of d = 3.4 nm, which is the first-order peak. This secondary peak is manifested by sufficiently performing the heat treatment described later, and as shown in FIG. 1 (a), the bimolecular film-like structure formed on the inner surface of the container is formed on the inner surface of the container. This shows that a large number of multi-molecular layer structures that are widely distributed and stacked in a direction perpendicular to the inner surface, that is, regularly arranged multi-molecular layers, are formed. It is preferred that it is expressed.

In the present invention, in particular, the primary peak and the secondary peak have a peak intensity ratio (secondary peak / primary peak) of 0.10 or more, most preferably 0.12 or more. preferable. That is, the larger the peak intensity ratio, the more regularly arranged multilayer structures are formed on the inner surface of the container.

The X-ray profile as described above is unique to the hot-filled package of the present invention. In the X-ray profile of a commercially available package, the secondary peak as well as the primary peak is also included. Not expressed. That is, since the hot-filled package of the present invention exhibits such an X-ray profile, for example, a highly ordered and regularly arranged multi-layered multilayer structure of lubricant is stable as shown in FIG. As a result, it exhibits excellent inverted fallability.

Such a hot-filled packaging body of the present invention is suitable as a bottle-shaped packaging container for use in viscous non-oil content that requires inverted fall of the contents, but in a cup shape. Even in this case, there is an advantage that the container contents can be taken out without remaining on the inner surface of the container, and the present invention can be applied to forms other than the bottle.
In addition, in a package that is hot-filled with non-oil content, the inner layer of the container is made of olefin resin, so it can be held stably for a long period of time so that moisture contained in the non-oil content is not released. Thus, it is possible not only to prevent the quality of the non-oil content from being degraded, but also to effectively avoid the performance degradation of the container due to swelling due to moisture, etc., and this is advantageous in terms of cost.

1. Polyolefin container The olefin-based resin forming the container inner surface in the hot-filled package of the present invention is not particularly limited, and examples thereof include low-density polyethylene, linear low-density polyethylene, medium- or high-density polyethylene, polypropylene, Examples thereof include poly 1-butene and poly 4-methyl-1-pentene. Of course, it may be a random or block copolymer of α-olefins such as ethylene, propylene, 1-butene and 4-methyl-1-pentene. Further, the melt flow rate (MFR, JIS K-6728) of such an olefin resin is generally in the range of about 0.1 to 3 g / 10 min.
In the present invention, particularly preferred olefin-based resins are polyethylene and polypropylene, and polyethylene is most suitable. In particular, to give squeeze property to a container and to squeeze out the contents of the container from the container. It is preferable to use low density polyethylene or linear low density polyethylene.

In the present invention, as long as the olefin resin layer containing the lubricant component as described above is formed on the inner surface of the container, the container wall may be formed by using the olefin resin layer as a single layer. The container wall may be formed by a multilayer structure in which the olefin-based resin layer is an inner surface layer and another resin layer is laminated thereon. In particular, in the case of a multilayer structure, the lubricant component blended in the olefin resin layer does not bleed on the outer surface of the container, but selectively bleeds on the inner surface of the container. There is an advantage that a sufficient multi-molecular multilayer structure can be formed on the inner surface of the container to exhibit a sufficient inverted fallability.

As an example of the multilayer structure as described above,
A five-layer structure of an inner surface layer (olefin resin layer) / adhesive layer / oxygen barrier layer / adhesive layer / outer surface layer is representative.
In such a layer structure, the adhesive layer is formed from an adhesive resin such as an acid-modified olefin resin, and the oxygen barrier layer is formed from an oxygen barrier resin such as an ethylene vinyl alcohol copolymer. Is done. In addition, a resin layer in which an oxygen absorbent such as iron powder is dispersed in an olefin resin or an oxygen barrier resin can be used as an oxygen barrier layer, or an oxidative resin component such as polybutadiene having an unsaturated double bond can be transitioned. An oxygen barrier layer can be prepared by blending with an oxygen barrier resin together with a metal catalyst. The outer surface layer is generally formed of the same olefin resin as the inner surface layer, but may be formed of other thermoplastic resin layers, for example, a polyester resin such as polyethylene terephthalate.

In such a multilayer structure, the lubricant component need only be provided on the inner surface layer, and basically does not need to be provided on other layers. Only the lubricant component blended in the inner surface layer contributes to the improvement in inverted fallability, and the ingredients blended in the other layers do not contribute to the improvement in fall fallability and only increase the cost. It is.

The multilayer structure is not limited to the five-layer structure described above. For example, the outer surface layer can be further formed into a multilayer structure using an oxygen barrier layer and an adhesive layer. Furthermore, an olefin-based resin layer containing no lubricant component may be provided adjacent to the inner layer, and this layer may have a multilayer structure in which an oxygen barrier layer is formed via an adhesive layer. Furthermore, without providing an oxygen barrier layer, it is possible to form a two-layer structure in which the inner surface layer is formed from low-density polyethylene, linear low-density polyethylene, or the like, and a high-density polyethylene layer with high printability is provided on the outer surface side.

In the present invention, the thickness of the olefin-based resin layer forming the inner surface of the container is not particularly limited, but it is usually preferable to set the thickness to at least 50 μm or more. If this thickness is too thin, a sufficient amount of the lubricant component for forming a multi-layer structure will not bleed, and as a result, the inverted fallability may be unsatisfactory. In the case of a multilayer structure, the various layers laminated on the inner surface layer may have a thickness according to the function. For example, the adhesive layer has a thickness that can secure a sufficient adhesive force. The oxygen barrier layer may have a thickness that exhibits good oxygen barrier properties and can effectively prevent deterioration of the contents due to oxygen permeation.

The polyolefin-based container as described above uses a resin (or resin composition) constituting each layer according to the layer structure of the container wall. For example, the molten parison is extruded from the die head by extrusion molding or coextrusion molding. It can also be manufactured by performing a known direct blow molding, or a preform for forming a test tube container is prepared by injection molding or co-injection molding, and this preform is transformed into a blow molding known per se. It is manufactured by attaching. Furthermore, a sheet-like preform can be molded and subjected to secondary molding such as plug-assist molding to form a cup-shaped container, or a film can be heat sealed to form a pouch-shaped container. You can also

2. Lubricant Component The polyolefin container in the hot-filled polyolefin package of the present invention has an olefin resin layer at least on the inner surface of the container, and a lubricant component is blended in the olefin resin layer on the inner surface of the container. As such a lubricant component, since it can form a multi-molecular multilayer structure as shown in FIG. 1 (a) in particular, it is composed of amphiphilic molecules such as behenic acid amide, stearic acid amide, palmitic acid amide. , Fatty acid amides such as lauric acid amide, capric acid amide, caproic acid amide, butyric acid amide, oleic acid amide, erucic acid amide, methylene bis-sulamide, methylene bissulamide, ethylene bis-oleic acid amide; stearic acid, lauric acid, Fatty acids such as palmitic acid, aliphatic alcohols such as cetyl alcohol, stearyl alcohol and cetyl alcohol, metal soaps such as zinc stearate and calcium stearate are used.

That is, an amphiphilic molecule has a nonpolar group such as a hydrocarbon group and a polar group such as an amide group or a carboxyl group, and has an affinity between polar groups due to formation of hydrogen bonds. For this reason, the lubricant molecules bleeding on the inner surface of the container are polymolecules as shown in FIG. 1 (a) due to the attraction between polar groups and the attraction by van der Waals forces acting between nonpolar groups. Easy to form a layer. For this reason, when the container is held upside down, it will fall down on such a multi-molecular layer, and for example, excellent inverted fallability will be developed even for viscous contents.

In the present invention, among the amphiphilic molecules as described above, fatty acid amides are most preferable from the viewpoint of easily forming a multimolecular multilayer structure as described above.
Of the fatty acid amides, fatty acid amides having a melting point of 85 ° C. or higher are particularly preferable, and saturated fatty acid amides are more preferable. That is, low melting point fatty acid amides and unsaturated fatty acid amides have high molecular thermal motility during the heat treatment described later. Therefore, in order to form a stable multi-molecular multilayer structure, heat treatment for a long time at a low temperature is required. However, a saturated fatty acid amide having a high melting point has low thermal mobility, and therefore, a stable multi-molecular multilayer structure can be formed by heat treatment at a high temperature in a short time. is there. Therefore, the saturated fatty acid amide having the above-mentioned melting point is most preferably used in the present invention, and particularly those having a carbon number in the range of 8 to 24, such as stearic acid amide and behenic acid amide are optimal. is there. In particular, such saturated aliphatic amides can be used alone, but other lubricant components (for example, oleic acid) may be used as long as a regularly arranged multi-molecular multilayer structure is formed by heat treatment in a short time. For example, other lubricants may be used on the condition that at least 20% by weight or more of the saturated fatty acid amide is contained in the lubricant component.

In the present invention, the above-mentioned lubricant component composed of amphiphilic molecules may be blended in an amount of 500 to 5000 ppm, particularly 700 to 5000 ppm, in the olefin resin layer forming the inner surface of the container. When this amount is small, a sufficient amount of the lubricant component does not bleed on the inner surface of the container, and as a result, it becomes difficult to form a well-ordered highly ordered multi-molecular layer in a sufficient amount, and the inverted fallability of the contents This is because, even if a lubricant component is added in excess of the above range, the inverted fallability of the contents will not be further improved, and it will be economically disadvantageous. .

<Manufacture of hot-fill packaging>
In the method for producing a hot-filled package of the present invention, a polyolefin container containing a pre-formed lubricant component is heat-treated, and the contents are hot-filled after the heat-treatment, thereby achieving the desired heat. An intermediate filling package can be obtained.

1. Heat treatment In the present invention, it is important to heat-treat before hot-filling the contents into the polyolefin container as described above. That is, by such heat treatment, the lubricant molecules bleeding on the inner layer of the bottle form a regular multi-molecular multilayer structure, and the slipperiness imparting effect by the lubricant is stably exhibited, as shown in the examples described later. In addition, the inverted fallability is remarkably improved with respect to the hot-filled contents such as ketchup, and when the packaging body is held upside down, the contents do not remain attached to the inner surface of the container and fall quickly.

In the package of the present invention in which the contents are hot-filled after the heat treatment as described above, the X-ray profile obtained when X-ray diffraction measurement is performed on the inner surface of the container by the reflection method Has a peak derived from the multi-layer structure of the lubricant formed on the inner surface of the container, and this is applied to a commercially available package (for example, a package in which ketchup is hot-filled). Such a peak is not shown.

In the present invention, the reason why the inverted fall property for the hot-filled contents is remarkably improved by the heat treatment as described above is not clearly elucidated, but the present inventors, From the above X-ray profile, the heat treatment before hot filling promotes the bleeding of the lubricant component on the inner surface of the container, and at the same time, the multilayer structure of the lubricant in which the lubricant molecules (amphiphilic molecules) that are bleeding on the inner surface of the container are regularly arranged. Is considered to be formed.
That is, in a container in which an olefin resin layer containing an amphiphilic molecule-containing lubricant is formed on the inner surface, the lubricant is bleeding on the inner surface, but the presence of the bleeding lubricant (amphiphilic molecule) is present. As shown in FIG. 1, as shown in FIG. 1, a highly ordered multi-layer structure in which lubricant molecules are arranged in a highly ordered and orderly manner (see FIG. 1A), and a multilayer structure in which lubricant molecules are arranged in a low order (see FIG. 1). 1 (b)) and a case where lubricant molecules are present randomly and a multilayer structure is not formed (see FIG. 1 (c)).

Then, it is considered that the above-described multi-molecular multilayer structure is formed on the inner surface of the container by performing the heat treatment prior to hot filling, and the heat treatment is sufficiently performed so that the above-described primary peak and secondary peak are expressed. When this is done, it is presumed that a highly ordered multi-molecular multilayer structure as shown in FIG. 1 (a) is formed.

As described above, in the present invention, a multilayered structure of the lubricant regularly arranged on the inner surface of the container is formed by the heat treatment before hot filling, and such a regularly arranged lubricant multilayer is stably and highly slippery. As a result, it is possible to obtain a hot-filled packaging body in which excellent inverted fallability is imparted to the hot-filled contents.

It is important to perform such heat treatment by non-contact heating at least on the inner surface of the container. This non-contact heating is not performed by contacting a heating member that applies pressure to the inner surface of the container, but is performed by holding at least the inner surface of the container in a free state. Generally, it is performed by oven heating or the like, but heat treatment can also be performed by induction heating or the like, and heat treatment can be performed by bringing a heating member into contact with the outer surface of the container unless pressure is applied to the inner surface of the container. it can. That is, by non-contact heating to the inner surface of the container, moderate kinetic energy is applied to the lubricant component (amphiphilic molecule) bleeding on the inner surface of the container, and the bleeding lubricant molecules are regularly arranged to provide a stable highly ordered polymolecule. A structure can be formed. For example, when the contents are hot-filled in the next step, a heat history is added to the inner surface of the container, but if heat treatment is not performed in advance, bleeding of the lubricant component is promoted, but the contents Since the objects come into contact with the inner surface of the container, the pressure of the container contents hinders the ordered arrangement of the lubricant molecules that bleed on the surface, and as a result, it is difficult to improve the inverted fallability of the contents. Because it becomes.

In the present invention, such heat treatment is performed such that the temperature of the inner surface of the container is maintained in the range of 50 to 110 ° C., particularly 70 to 110 ° C. That is, when the heat treatment temperature is less than 50 ° C., a regularly arranged multi-molecular multilayer structure cannot be formed, and therefore the inverted fallability of the contents becomes unsatisfactory. Moreover, if it is less than 70 degreeC, compared with the case where it is 70 degreeC or more, a process for a long time will be required, and productivity may be inferior and there exists a possibility of causing an increase in cost. In addition, when the heat treatment temperature is set higher than 110 ° C., the thermal movement of the lubricant molecules bleeding on the surface becomes intense, and it tends to be difficult to form a regularly arranged multimolecular multilayer structure. There is also a risk of causing thermal deformation of the container.

In general, the heat treatment time is preferably in the range of 1/6 to 10 minutes. In particular, when the heat treatment temperature is T ° C. and the heat treatment time is t minutes, the following formula:
45 ≦ T · t ≦ 1100
It is preferable to set the heat treatment time so as to satisfy the above condition. That is, when the heat treatment temperature is set high, a highly ordered multi-molecular multilayer structure as shown in FIG. 1 (a), for example, is developed by heat treatment in a short time, and the best inverted fall property is exhibited. Can be expressed. If the heat treatment time is set low, it takes a long time to obtain a highly ordered polymolecular structure.

In the present invention, particularly when a saturated aliphatic amide having a melting point of 85 ° C. or higher (for example, stearamide) is used as the above-mentioned lubricant component, it is shown in FIG. Such a highly ordered multi-molecular multilayer structure can be formed. Specifically, when such a lubricant component is used, a highly ordered multi-layer structure is formed in a heat treatment time of 2 to 10 minutes by setting the heat treatment temperature in the range of 80 to 110 ° C. It is possible to develop the best inverted fallability.

2. Hot filling of contents;
In the present invention, hot filling of the contents is performed after the heat treatment as described above.
The hot-filled contents are not particularly limited, but the hot-filling is for the purpose of sterilizing the contents and the container, and in particular, non-oily contents are applied. This is because the non-oil content tends to cause bacterial growth and requires heat sterilization.

In addition, the content to which the present invention is most preferably applied is ketchup, but other examples include sauce and liquid paste. Among such non-oil contents, a particularly viscous paste or slurry (for example, a viscosity at 25 ° C. of 100 cps or more) is preferable. This is because such a viscous content is desired to be able to be discharged out of the container without remaining attached to the container wall. Moreover, since it is hot-filled, foods such as ketchup and sauce are suitable.

The temperature of hot filling is usually 60 ° C. or higher, particularly in the range of 60 to 90 ° C. This is because when the temperature is too low, sterilization by hot filling becomes insufficient, and when the temperature is higher than necessary, the content is altered (moisture volatilization).

In addition, when the contents are hot-filled, a heat history is generated on the inner surface of the container, and as in the case of performing the heat treatment before the contents are hot-filled, a regularly arranged lubricant multi-molecular layer may be formed. Conceivable. However, the hot filling does not form a regularly arranged lubricant multilayer structure, for example, a layer as shown in FIG. That is, in the heat history due to hot filling of the contents, the pressure by the contents is applied to the inner surface of the container, and as a result, the thermal motion of the lubricant molecules is suppressed and the regular arrangement is inhibited.

On the other hand, in the heat treatment before hot filling of the contents of the present invention, the inner surface of the container is heat treated by non-contact heating, so that the thermal motion of the lubricant molecules is not suppressed during the heat treatment, and the multilayer structure in which the lubricant molecules are regularly arranged. In addition, the multilayer structure is not destroyed by hot filling of the contents because the lubricant molecules are regularly arranged.

The present invention will be described in the following experimental examples.
In addition, the content sliding property and X-ray-diffraction measurement about the package manufactured by each experiment were performed with the following method.

1. Content sliding test At room temperature, 50 g of the contents were taken out from the cap attached to the container, and then inverted and left for 10 minutes to confirm the state of adhesion of the contents on the inner surface of the container. Thereafter, the bottle was stored upright at 5 ° C. for 24 to 72 hours, and then the container containing the contents was taken out again, and the sliding test was repeated until the contents disappeared by the above method. The contents of the contents of the inner surface of each container after standing for 10 minutes in an inverted state are visually confirmed. The best sliding property is marked with ◎, the worst is marked with ×, and the best to worst In order, the sliding property of the contents was evaluated in four stages of ◎, ○, Δ, and ×.

2. X-ray diffraction measurement After the content sliding test, cut out a 25 mm x 20 mm test piece from the cleaned container body, attach it to the measurement cell, attach it to the sample table so that the inner surface of the container is the measurement surface, and use Cu as the target Then, X-ray diffraction measurement (manufactured by Rigaku Corporation) was performed by the reflection method in the range of 2θ = 1.7 to 10 ° under the conditions of an acceleration voltage of 40 KV and an acceleration current of 200 mA. Air scattering correction was performed on the obtained measurement data, and this was used as sample data.

(Examples 1 to 11)
Melting and kneading using a twin-screw extruder so that the innermost layer is a mixed resin layer of low-density polyethylene resin and various fatty acid amides, melt-extrusion with other resins to form a parison, and blow-molding the resulting parison Then, a multilayer container (capacity: 500 mL) having the following layer configuration was produced. A low density polyethylene resin was used as the outermost layer resin, and a maleic anhydride-modified polyethylene resin was used as the adhesive. Table 1 shows the types and amounts of various fatty acids used for the innermost layer.
Outermost layer / adhesive layer / barrier layer (EVOH) / adhesive layer / LDPE layer / innermost layer)
Thickness of each layer of container body Outermost layer thickness: 25 μm
Adhesive layer thickness: 10 μm for both the outermost layer and the innermost layer
Barrier layer thickness: 20 μm
LDPE layer thickness: 180 μm
Innermost layer thickness: 180 μm

After the container was formed, heat treatment was performed under the treatment conditions shown in Table 1 using a blower constant temperature dryer (Windy Oven WFO-450SD, manufactured by Tokyo Rika Kikai Co., Ltd.).
After the heat treatment, the container was taken out and stored overnight at 22 ° C. and 60% RH. About 500 g of tomato ketchup (manufactured by Kagome Co., Ltd.) was hot-filled (80 to 85 ° C.) in the stored container, and the mouth was sealed with a sealing material, and then the container was cooled in water. After cooling, it was stored for 1 week in an environment of 22 ° C. and 60% RH, and then the sealing material was peeled off and a cap was attached. About the obtained container, the above-mentioned content sliding test and X-ray-diffraction measurement were done. The results are shown in Table 1. Moreover, the X-ray-diffraction measurement result of Example 6 is shown in FIG.

(Example 12)
Except that the innermost layer is a mixed resin layer of a blend of low density polyethylene resin and various fatty acid amides (where the weight ratio of oleic amide, erucic acid amide, stearic acid amide is 2: 1: 7). Multilayer containers were produced in the same manner as in Examples 1-11. The obtained container was subjected to the above-described content sliding test and X-ray diffraction measurement. The results are shown in Table 1.

(Comparative Examples 1 and 2)
Except that the innermost layer is a mixed resin layer in which 0.03 part by weight (Comparative Example 1) or 0.1 part by weight (Comparative Example 2) of oleic amide is mixed with 100 parts by weight of the low-density polyethylene resin. A multilayer container was produced in the same manner as in Examples 1-12. The obtained container was subjected to the above-described content sliding test and X-ray diffraction measurement. The results are shown in Table 1. Moreover, the X-ray-diffraction measurement result of the comparative example 2 is shown in FIG.

(Comparative Examples 3 to 7)
The above-mentioned content sliding test and X-ray diffraction measurement were performed on a commercially available viscous food container. The results are shown in Table 1.

From the experimental results in Table 1, it can be seen from the X-ray diffraction measurement from the inner surface of the container that the sliding property is improved in the multilayer container having a peak derived from the lubricant multilayer structure.
It can also be seen that the sliding property is further improved as the ratio of the primary peak to the secondary peak (secondary peak / primary peak) in the X-ray diffraction measurement is larger. In addition, it can be seen that even if the fatty acid amide is not a stearic acid amide alone, which is a saturated fatty acid amide, but also a blend of a saturated fatty acid amide and an unsaturated fatty acid amide, the sliding property is improved by heat treatment. On the other hand, as shown in FIG. 3, it can be seen that those in which no peak is observed in the X-ray diffraction measurement have no sliding property and no multi-molecular layer structure is formed on the inner surface of the container.

Claims

In a package in which the contents are hot-filled in a polyolefin container in which an olefin-based resin layer containing an amphiphilic molecule containing a lubricant component is formed on the inner surface, the hot-filled contents are taken out. When the X-ray diffraction measurement by the reflection method is performed on the inner surface of the container, the resulting X-ray profile expresses a peak derived from the lubricant multi-layer structure formed on the inner surface of the container A hot-filled package.
The heat according to claim 1, wherein the X-ray profile expresses a primary peak derived from a lubricant multilayer structure formed on the inner surface of the container and a secondary peak derived from the multilayer structure. Inter-packaging package.
The hot filling according to claim 2, wherein the primary peak and the secondary peak expressed in the X-ray profile have a peak intensity ratio (secondary peak / primary peak) of 0.12 or more. Packaging body.
The olefin resin layer formed on the inner surface of the container contains the lubricant component in an amount of 0.05 to 0.5 parts by weight with respect to 100 parts by weight of the olefin resin. Hot-packed packaging body.
The hot-filled package according to claim 1, wherein the olefin-based resin layer contains a fatty acid amide having a melting point of 85 ° C or higher as a lubricant component.
The hot-filled package according to claim 5, wherein the fatty acid amide is a saturated fatty acid amide.
The hot-filled package according to claim 1, wherein the olefin-based resin is a polyethylene resin.
The hot-filled package according to claim 1, wherein the polyolefin container has a multilayer structure having the olefin-based resin as an innermost layer.
The hot-filled package according to claim 1, wherein the hot-filled contents are non-oily substances.
A method for producing a package in which a polyolefin container in which an olefin-based resin layer containing an amphiphilic molecule containing a lubricant component is formed on the inner surface is hot-filled with the contents, and at least the inner surface of the container after the container is molded A method for producing a hot-filled package, characterized in that a heat treatment is performed by non-contact heating and then the contents are hot-filled.
The method for manufacturing a hot-filled package according to claim 10, wherein the heat treatment is performed at 70 to 110 ° C for 1/6 to 10 minutes.
When the heat treatment temperature is T ° C. and the heat treatment time is t minutes, the following formula:
45 ≦ T · t ≦ 1100
The manufacturing method of the hot filling package body of Claim 11 which heat-processes so that these conditions may be satisfied.
The method for producing a hot-filled package according to claim 10, wherein the hot-filling is performed at a temperature of 60 ° C or higher.