JP2018020849A - Packaging container with viscous content housed therein - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a content-containing packaging container having a multilayer structure and enabling a viscous content to be quickly discharged.SOLUTION: A plastic-made packaging container with a content including a viscous water component housed therein is provided. The liquid layer of an oily liquid of 0.2-50 g/mis formed on the face contacting with the content. The container wall of the packaging container has a ground layer, a liquid diffusion-preventive layer, a middle interposition layer and an oxygen barrier layer in this order. The ground layer is composed of an olefinic resin having a density less than 1.0 g/cm, and the oily liquid penetrates into the ground layer from the liquid layer. Each of the liquid diffusion-preventive layer and the oxygen barrier layer includes 60 mass% or more of ethylene-vinyl alcohol copolymer having a density of 1.0 g/cmor more and a glass transition point of 35°C or higher. A ratio d/D is 30 to 70% when the thickness of the middle interposition layer is represented as d, and the whole thickness of the container as D.SELECTED DRAWING: Figure 1

Description

The present invention relates to a packaging container in which viscous contents, particularly viscous contents such as sauce, mayonnaise, ketchup and the like are accommodated .

  Plastics are widely used for various applications because they are easy to mold and can be easily molded into various forms. In particular, bottle-shaped olefin-based resin containers whose inner walls are formed of olefin-based resins such as low-density polyethylene are easy to squeeze out the contents, so that the contents of viscous slurry or paste such as ketchup It is suitably used as a container for containing things.

  For bottles containing viscous contents, the bottles may be stored in an inverted state so that the contents can be discharged quickly or used up to the end without remaining in the bottle. There are many. Therefore, when the bottle is turned upside down, there is a demand for the characteristic that the viscous contents do not remain attached to the inner wall surface of the bottle and fall quickly.

As a bottle satisfying such requirements, for example, Patent Document 1 proposes a bottle having a multilayer structure in which an innermost layer is made of an olefin resin having an MFR (melt flow rate) of 10 g / 10 min or more.
In this multi-layered bottle, the innermost layer has excellent wettability to oily contents. As a result, when the bottle is inverted or tilted, the oily contents such as mayonnaise spread along the innermost surface. However, it can be discharged neatly without dropping and remaining attached to the inner wall surface of the bottle (the innermost layer surface).

  In addition, regarding a bottle for viscous non-oil content in which plant fibers such as ketchup are dispersed in water, Patent Document 2 or Patent Document 3 describes a saturated or unsaturated aliphatic amide as a lubricant in the innermost layer. There has been proposed a polyolefin resin bottle in which is blended.

  Patent Documents 1 to 3 mentioned above all improve the slipperiness with respect to the contents by the chemical composition of the thermoplastic resin composition forming the inner surface of the plastic container, and a certain degree of slipperiness improvement is achieved. However, since the types and additives of the thermoplastic resin to be used are limited, there is a limit in improving the slipperiness, and the fact is that a dramatic improvement has not been achieved.

From this point of view, the present inventor has proposed a plastic container in which a liquid layer is formed on the inner surface in contact with the contents (for example, Japanese Patent Application Nos. 2012-1992236, 2013-23468 and (Japanese Patent Application No. 2013-091244).
That is, all of these have succeeded in significantly improving the slipperiness with respect to the contents by forming a liquid layer that is immiscible with the contents as compared with the conventionally known ones. By inverting or tilting, the contents can be quickly discharged out of the container without adhering to or remaining on the inner wall of the container.
Thus, the molded body having a structure in which a liquid layer is formed on the surface is applicable not only to the shape of the container but also to a molded body having a form such as a film. These properties can be greatly modified.

However, in a structure having a liquid layer on the surface, properties such as excellent slipperiness due to the liquid layer are lost with time. For example, after a few days have passed after manufacturing, the properties imparted by the liquid layer are greatly reduced. There is a problem of end up.
As a multilayer structure container in which such problems have been solved, the applicant previously has a liquid layer on the surface of the plastic underlayer, and the liquid layer is formed under the underlayer. Proposed a multilayer structure container provided with a liquid diffusion preventing layer for suppressing or blocking the diffusion of the liquid to be transferred (Japanese Patent Laid-Open No. 2013-109059). Such a multilayer container has a problem that a sufficient oxygen barrier property cannot be obtained. That is, since the liquid diffusion prevention layer can be formed of a typical ethylene-vinyl alcohol copolymer as an oxygen barrier resin, a sufficient oxygen barrier property can be originally secured. According to experiments conducted by the present inventors, it has been found that in a mode in which a liquid layer is formed on the inner surface, when the container is filled with contents containing moisture, the oxygen barrier property is significantly reduced. It was.

JP 2007-284066 A JP 2008-222291 A JP 2009-214914 A JP-A-6-345903

  Therefore, an object of the present invention is to have a liquid layer on the surface, the surface characteristics of the liquid layer are stably maintained over a long period of time, and excellent slipperiness for viscous contents is exhibited over a long period of time. Another object is to provide a packaging container having a multilayer structure excellent in oxygen barrier properties.

That is, according to the present invention, a plastic packaging container in which a content containing moisture having viscosity is stored ,
A liquid layer of 0.2 to 50 g / m ^{2 of} an oily liquid is formed on the surface in contact with the contents,
The container wall of the packaging container functions as a base layer serving as a base of the liquid layer, a liquid diffusion preventing layer provided adjacent to the base layer and preventing permeation and diffusion of oily liquid from the liquid layer. The first oxygen barrier resin layer and the first oxygen barrier resin layer include a second oxygen barrier resin layer formed at an interval from the first oxygen barrier resin layer. Between the two oxygen barrier resin layers, an intermediate intervening layer is provided for defining the distance between the two layers.
The underlayer is made of an olefin resin having a density of less than 1.0 g / cm ^3, and the oil liquid penetrates from the liquid layer into the underlayer,
Each of the first and second oxygen barrier resin layers contains 60% by mass or more of an ethylene-vinyl alcohol copolymer having a density of 1.0 g / cm ³ or more and a glass transition point Tg of 35 ° C. or more. Layer,
Provided is a plastic packaging container characterized in that the ratio of d ₁ / D is 30 to 70%, where d _{1 is} the thickness of the intermediate intervening layer and D is the total thickness of the container.

In the plastic packaging container of the present invention,
(1) The thickness of the first oxygen barrier resin layer (hereinafter simply referred to as a liquid diffusion prevention layer) functioning as the liquid diffusion prevention layer is the same as that of the second oxygen barrier resin layer (hereinafter simply referred to as oxygen barrier property). In the range of 50 to 300% of the thickness of the resin layer)
(2) The liquid layer is formed in an amount of 0.2 to 10 g / m ² ,
(3) The intermediate intervening layer includes a polyolefin resin layer,
Is preferred.

  The plastic packaging container of the present invention includes a liquid layer on the inner surface, and this liquid layer can cause various surface characteristics to be expressed in the multilayer structure. For example, when this liquid layer is formed of an oleaginous liquid such as a fluorosurfactant or vegetable oil, it is possible to effectively prevent the adhesion of an aqueous substance such as water to the surface, and further, aqueous The slipperiness with respect to a substance is remarkably improved. Further, when the liquid layer is formed of an oil-repellent liquid, it is possible to prevent the oily substance from adhering to the surface and to further improve the slipperiness with respect to the oily substance.

  Further, in the plastic packaging container of the present invention, a liquid diffusion preventing layer for preventing the permeation and diffusion of the liquid forming the liquid layer is formed below the base layer holding the liquid layer. For example, the surface characteristics expressed by the liquid layer are stably maintained over about one month or more. That is, the liquid diffusion preventing layer is a dense resin layer containing an ethylene-vinyl alcohol copolymer, and the liquid layer formed on the surface penetrates and diffuses into the container wall. As a result, the amount of liquid forming the liquid layer on the surface is always kept above a certain level, thus effectively avoiding the deterioration of the surface characteristics over time due to the decrease in the liquid layer. Yes.

  Furthermore, in the packaging container of this invention, the oxygen barrier property resin layer containing an ethylene-vinyl alcohol copolymer is provided in the further outer side of the liquid diffusion prevention layer containing an ethylene-vinyl alcohol copolymer.

  That is, since the liquid diffusion preventing layer contains the ethylene-vinyl alcohol copolymer having the most excellent oxygen barrier properties, the oxygen diffusion preventing layer should originally exhibit excellent oxygen barrier properties only with this liquid diffusion preventing layer. As is apparent from the experimental results (Experimental Example 8) described later, the oxygen barrier property is not sufficiently exhibited in the embodiment using only the liquid diffusion prevention layer. When compared with the same thickness, it is about 1/6 of the oxygen barrier property of a normal ethylene-vinyl alcohol copolymer layer. The ethylene-vinyl alcohol copolymer does not sufficiently exhibit oxygen barrier properties in the presence of moisture, and the liquid diffusion prevention layer is located near the inner surface of the container in which the liquid layer is formed (i.e., water vapor). Formed at a high pressure position). For this reason, it is presumed that the oxygen barrier property of the ethylene-vinyl alcohol copolymer is not sufficiently exhibited only by means of forming the ethylene-vinyl alcohol copolymer as a liquid diffusion preventing layer.

  However, in the present invention, an oxygen barrier resin layer (hereinafter simply referred to as an oxygen barrier layer) containing an ethylene-vinyl alcohol copolymer is formed on the outer side of the liquid diffusion preventing layer. This oxygen barrier layer is formed at a position far from the inner surface of the container having a high water vapor pressure. For this reason, it is hardly influenced by moisture, and therefore the ethylene-vinyl alcohol copolymer forming this oxygen barrier layer exhibits a sufficient oxygen barrier property.

  Thus, according to the plastic packaging container of the present invention, excellent slipperiness for viscous contents is exhibited over a long period of time, and a liquid layer is formed on the inner surface to exhibit such slipperiness. Therefore, it is possible to effectively avoid the deterioration of the oxygen barrier property, and to exhibit the excellent oxygen barrier property stably over a long period of time.

The schematic sectional drawing which shows an example of the layer structure of the packaging container of this invention.

<Layer structure of packaging container>
Referring to FIG. 1 showing an example of the layer structure of the packaging container of the present invention, the container wall indicated by 20 as a whole has a liquid diffusion preventing layer 1 and an oxygen barrier layer 3 as intermediate layers. 3 is located on the outer surface side of the liquid diffusion preventing layer 1, and the liquid layer 5 is formed on the inner surface of the container wall 20.
Further, in this layer structure, the liquid layer 5 is formed on the base layer 7, and the base layer 7 exists between the liquid layer 5 and the liquid diffusion preventing layer 1. An intermediate intervening layer 9 exists between the liquid diffusion preventing layer 1 and the oxygen barrier layer 3, and an outer surface layer 11 made of a predetermined container base resin is provided outside the oxygen barrier layer 3. ing.

Liquid diffusion prevention layer 1;
The liquid diffusion preventing layer 1 blocks the penetration and diffusion of the liquid that forms the liquid layer 5, and by forming such a layer, the surface characteristics imparted by the liquid layer 5 can be stabilized over a long period of time. Will be maintained.
That is, although the liquid layer 5 is formed by various means (this means will be described later), no matter what means is used to form the liquid layer 5, the liquid that forms the liquid layer 5 is the underlayer. 7 penetrates and diffuses inside the container wall 20. That is, even if the liquid layer 5 is formed with a certain amount of liquid, the liquid gradually moves into the container wall 20, so that the liquid amount decreases with time. As a result, the liquid layer The surface properties imparted by 5 will be lost over time. However, in the present invention, since the permeation and diffusion of the liquid from the liquid layer 5 is blocked by the presence of the liquid diffusion preventing layer 1, the decrease in the liquid volume of the liquid layer 5 is effectively suppressed, and the surface characteristics are lost over time. It can be avoided.

The liquid diffusion preventing layer 1 is made of a dense thermoplastic resin (for example, a density of 1.00 g / cm ³ or more and a glass transition point Tg of 35 so as to prevent permeation and diffusion of the liquid from the liquid layer 5. Resin) at a temperature higher than or equal to 0 ° C., particularly including an ethylene-vinyl alcohol copolymer (saponified ethylene / vinyl acetate copolymer). For example, the liquid diffusion preventing layer 1 is formed only by the ethylene-vinyl alcohol copolymer. It may be formed, or may be a blend with another thermoplastic resin as long as the permeation diffusion preventing ability is not impaired. For example, the liquid diffusion preventing layer 1 can be formed from a blend containing an ethylene-vinyl alcohol copolymer in an amount of 60% by mass or more. The liquid diffusion preventing layer 1 formed of such a blend has good adhesion to the underlayer 7 or the intermediate intervening layer 9 of the liquid layer 5, and the liquid diffusion preventing layer 1 is exceptionally disposed between these layers. There is an advantage that it is not necessary to provide an adhesive layer (hereinafter also referred to as an adhesive layer).

  In the present invention, from the viewpoint of preventing the permeation and diffusion of the liquid, the liquid diffusion preventing layer 1 may be formed from a metal foil, a metal vapor deposition film, or an inorganic material such as glass or ceramics. In the liquid diffusion preventing layer 1 with such an inorganic material, the forming means is limited, and the form of the multilayer structure is limited to a film or the like, which makes it difficult to form into a container form. However, when the liquid diffusion preventing layer 1 is formed of a thermoplastic resin containing an ethylene-vinyl alcohol copolymer as described above, it can be formed into a container by various molding means, such as a blow molded container. The form of can also be taken.

  The ethylene-vinyl alcohol copolymer (hereinafter sometimes abbreviated as EVOH) is generally an ethylene-vinyl acetate copolymer having an ethylene content of 20 to 60 mol%, particularly 25 to 50 mol%. Is preferably a saponified copolymer obtained by saponification such that the saponification degree is 96 mol% or more, particularly 99 mol% or more, and among these, the density and the glass transition point (Tg) are as described above. Those within the specified range should be used selectively.

  The liquid diffusion preventing layer 1 described above is a layer for preventing the permeation and diffusion of the liquid from the liquid layer 5 into the container wall 20, but in the present invention, an oxygen barrier due to moisture in the oxygen barrier layer 3 described later. It also has a function of preventing the deterioration of sex. That is, the presence of the liquid diffusion preventing layer 1 can increase the interval between the oxygen barrier layer 3 and the inner surface of the container, which will be described later, and can reduce the influence on moisture in the container. EVOH that forms water absorbs moisture and functions as a moisture barrier layer.

  Such a liquid diffusion preventing layer 1 needs to be relatively thick in order to surely prevent the penetration of liquid from the liquid layer 5 and to prevent the oxygen barrier layer 3 from being deteriorated by moisture. The thickness varies depending on the period in which liquid penetration needs to be prevented, but is at least 2 μm or more, and in particular, the thickness of the container wall 20 needs to be about 50 to 300% of the thickness of the oxygen barrier layer 3 described later. This is preferable in that it is not thickened.

Oxygen barrier layer 3;
The oxygen barrier layer 3 blocks the permeation of oxygen into the container, thereby preventing oxidative deterioration of the contents.
Such an oxygen barrier layer 3 is formed from an ethylene-vinyl alcohol copolymer (EVOH) exhibiting particularly excellent oxygen barrier properties among oxygen barrier resins. This EVOH is the same as the EVOH used for forming the liquid diffusion preventing layer 1 described above. For example, an ethylene-vinyl acetate copolymer having an ethylene content of 20 to 60 mol%, particularly 25 to 50 mol%, is obtained by saponification so that the saponification degree is 96 mol% or more, particularly 99 mol% or more. The saponified copolymer obtained is preferably used.

  In the oxygen barrier layer 3, even if other resins are blended in such an amount that the excellent oxygen barrier property of EVOH is not impaired, for example, in a range where EVOH is 60% by mass or more. Good. That is, like the liquid diffusion prevention layer 1 described above, by blending the oxygen barrier layer 3 with a resin (for example, a container base resin) that forms the intermediate intervening layer 9 and the outer surface layer 11 adjacent thereto, The adhesion between these adjacent layers 9 and 11 and the oxygen barrier layer 3 can be enhanced.

  In the present invention, the thickness of the oxygen barrier layer 3 usually needs to be 4 μm or more, preferably 10 μm to 40 μm, and more preferably 10 μm to 30 μm.

In the present invention, the oxygen barrier layer 3 is preferably separated from the liquid diffusion preventing layer 1 as much as possible. For example, the total thickness of the container is D (excluding the thickness of the liquid layer), oxygen When the distance d ₁ between the barrier layer 3 and the liquid diffusion preventing layer 1 is set, it is desirable that the ratio d ₁ / D of these values be 30% or more, particularly 35 to 70%. That is, setting d ₁ and D so as to be in such a range separates the oxygen barrier layer 3 from the liquid diffusion preventing layer 1 that forms the liquid layer 5 and blocks the liquid that easily absorbs moisture. By disposing the oxygen barrier layer 3 at a position closer to the outer surface side than the inner surface side, the influence of moisture is suppressed, and the gas barrier property deterioration due to the moisture of EVOH forming the oxygen barrier layer 3 is more effectively prevented. It becomes possible to prevent.

Liquid layer 5;
The liquid layer 5 formed on the inner surface of the container wall 20 is formed of an appropriate liquid so that slipperiness and water repellency are imparted according to the type of the container contents. The liquid layer 5 is formed by a non-volatile liquid having a low vapor pressure under atmospheric pressure, for example, a high boiling point liquid having a boiling point of 200 ° C. or higher. When the liquid layer 5 is formed of a volatile liquid, the liquid layer 5 is easily volatilized and disappears with time, or it is difficult to form the liquid layer 5, depending on the usage form. Because.

  Specific examples of the liquid forming the liquid layer 5 include various liquids provided that the liquid layer 5 is a high-boiling liquid as described above. In order to impart aqueous properties and slipperiness, fluorine surfactants, silicone oils, fatty acid triglycerides, various vegetable oils and the like are representative. Examples of vegetable oils include soybean oil, rapeseed oil, olive oil, rice oil, corn oil, ben flower oil, sesame oil, palm oil, castor oil, avocado oil, coconut oil, almond oil, walnut oil, sandwich oil, salad oil, etc. It is done.

The liquid layer 5 formed from such a liquid generally has a liquid amount of 0.2 to 50 g / m ² , preferably 0.2 to 30 g / m, although it varies depending on the target surface characteristics and the type of liquid. ^2, more preferably 0.5 to 30 g / ^{m 2,} dramatically preferably it is formed to be in the range of 0.5 to 10 g / ^{m 2.} That is, if the amount of liquid is small, sufficient surface properties cannot be imparted. On the other hand, if the amount of liquid is excessively large, the liquid tends to drop off, resulting in large fluctuations in the amount of liquid and a stable surface. This is because the characteristics may not be ensured.

Further, in the present invention, such a liquid layer 5 is provided with the following formula (1) in order to stably and uniformly impart surface characteristics due to the liquid:
F = (cos θ−cos θ _B ) / (cos θ _A −cos θ _B ) (1)
Where
θ is a water contact angle on the inner surface of the container wall 20,
θ _A is a water contact angle on the liquid forming the liquid layer 5;
θ _B is a water contact angle on a single plastic that forms a layer (underlayer 7 described later) that supports the liquid layer 5.
It should be formed so that the coverage F of the liquid layer calculated in (1) is 0.5 or more, preferably 0.6 or more. That is, when the water contact angle θ on the inner surface of the container wall 20 and the water contact angle water θ _A on the liquid layer 5 are the same, the coverage F is 1.0, and the underlayer 7 The whole is covered with the liquid layer 5.
For example, when the coverage F is smaller than the above range, the liquid layer 5 is formed in such a form that the liquid is scattered on the surface even if the liquid amount is large, and it is difficult to exhibit sufficient surface characteristics. End up.

Here, when the surface is a composite surface formed from two types of components (A, B), the above equation (1) is obtained by modifying the Cassie-Baxter equation that expresses the apparent contact angle θ. can get. This is expressed by the following equation.
cos θ = F _A cos θ _A + F _B cos θ _B
= F _A cos θ _A + (1−F _A ) cos θ _B
Where
The proportion of the A component is F _A , the proportion of the B component is F _B , F _A + F _B = 1
The contact angle on the A component alone is θ _A , and the contact angle on the B component alone is θ _B.

Underlayer 7;
The base layer 7 that supports the liquid layer 5 described above is adjacent to the inner surface side of the liquid diffusion preventing layer 1 and is a layer for holding the liquid layer 5 formed on the surface so as not to drop off. That is, if the liquid layer 5 is formed directly on the liquid diffusion preventing layer 1, the liquid forming the liquid layer 5 does not permeate. It becomes difficult to form the liquid layer 5 stably. For this reason, it is desirable to provide the base layer 7 and form the liquid layer 5 thereon.

Thus, the base layer 7 allows the liquid to penetrate from the liquid layer 5 to some extent, and exhibits an anchor effect with respect to the liquid layer 5. Therefore, compared with the liquid diffusion preventing layer 1, it is formed of a relatively loose resin, for example, a thermoplastic resin having a density of less than 1.0 g / cm ³ .

  The thermoplastic resin for forming such an underlayer 7 is not particularly limited as long as it has a molecular weight sufficient to form a layer and the density is within the above range, but in general, an olefin resin. , Low density polyethylene, linear low density polyethylene, medium or high density polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, and the like. Of course, it may be a random or block copolymer of α-olefins such as ethylene, propylene, 1-butene and 4-methyl-1-pentene. In addition, other resins may be blended with these olefin resins as long as the penetration of the liquid from the liquid layer 5 can be allowed to some extent. In the present invention, the olefin-based resin for forming the underlayer 7 which is particularly preferably used is polyethylene or polypropylene, and polyethylene is most suitable. In particular, when the container having the container wall 20 is used as a squeeze container for squeezing the contents, it is preferable to form the underlayer 7 using low-density polyethylene or linear low-density polyethylene.

The thickness _{d 2} of the base layer 7, 5 to 200 [mu] m, preferably it is preferred that 10 to 150 [mu] m, more preferably in the range of 20 to 100 [mu] m. That is, when the thickness d ₂ is too thin, the anchor effect is insufficient for the liquid layer 5, is likely to occur falling off of the liquid from the liquid layer 5. On the other hand, if the thickness d ₂ is excessively thick, even if the liquid diffusion preventing layer 1 prevents the liquid from penetrating and spreading, the amount of liquid that can penetrate into the underlayer 7 increases, and the liquid layer 5 changes over time. There is a risk that it is difficult to suppress disappearance.

  Although the surface of the underlayer 7 (interface with the liquid layer 5) varies depending on the forming means of the liquid layer 5, the liquid layer 5 is effectively prevented from falling off and the liquid layer 5 is stably held. In addition, the surface of the liquid layer 5 can be appropriately uneven so that the liquid can penetrate effectively. That is, the uneven surface on which the liquid can effectively permeate the surface of the underlayer 7 is a surface in which the contact angle θ of the liquid is less than 90 degrees and the capillary phenomenon is dominant as compared with gravity.

The range where the capillary phenomenon is dominant is called the capillary length (τ ⁻¹ ) and is expressed by the following formula.
τ ⁻¹ = (γa / ρg) ^1/2
Where γa is the interfacial tension between the liquid and gas (air),
ρ is the density of the liquid,
g is a gravitational acceleration.
That is, in the range below the capillary length (τ ⁻¹ ), capillary action (capillary force) becomes dominant as compared to gravity. As can be understood from the above formula, the capillary length is constant depending on the liquid regardless of the material of the base layer 7, and is about 2.7 mm for water, for example. Therefore, for example, in order to obtain a liquid-permeable uneven surface, the inner diameter of the recess may be set to a capillary length (τ ⁻¹ ) or less. Although this capillary length varies depending on the type of liquid forming the liquid layer 5, it is in the range exceeding 1 mm for many liquids, so if the concave portions having an inner diameter of 1 mm or less are distributed over the entire surface of the underlayer 7. Good. In this case, the depth and pitch of the recesses and the density of the recesses (the number of recesses per unit area) vary depending on the type of liquid that forms the liquid layer 5, but usually the liquid that forms the liquid layer 5 the amount of 0.2 to 50 g / ^{m 2,} preferably maintained 0.2 to 30 g / ^{m 2,} more preferably 0.5 to 30 g / ^{m 2,} much preferably in the range of 0.5 to 10 g / ^{m 2} It should be set so that.
In particular, when the liquid layer 5 is formed by spraying or applying a liquid after forming the base layer 7, the formation of the uneven surface as described above is particularly effective.

  Typical means for forming the uneven surface as described above are mechanical means such as a mold, roll transfer, embossing, and optical means such as etching using photolithography or laser light. In addition, the surface of the underlayer 7 can be coated with fine particles (metal oxide fine particles or polymer fine particles), a porous body, a crystalline additive, etc. to form an uneven surface. An uneven surface can also be formed by molding the base layer 7 by mixing with a resin forming the base layer 7 by kneading or the like.

Furthermore, in the present invention, the liquid for forming the liquid layer 5 can be blended with the base layer 7 as described above, and the base layer 7 can be used as a liquid supply source for forming the liquid layer 5. That is, the liquid layer 5 can be formed by blending with the base layer 7 formed of the above-described low-density resin having a high liquid permeation diffusibility. Since the liquid diffusion prevention layer 1 is formed on the other side of the underlayer 7, the liquid blended with the underlayer 7 oozes onto the surface of the underlayer 7, thereby forming the liquid layer 5. Can do. The amount of liquid blended into the underlayer 7 is also described above, but generally the amount of liquid that oozes onto the surface to form the liquid layer 5 is 0.2 to 50 g / m ² , preferably 0.2 to 30 g. / ^{m 2,} more preferably 0.5 to 30 g / ^{m 2,} much preferably may be set so as to be maintained in the range of 0.5 to 10 g / ^{m 2.}

Intermediate intervening layer 9;
The intermediate intervening layer 9 is provided between the liquid diffusion preventing layer 1 and the oxygen barrier layer 3, and by separating the oxygen barrier layer 3 from the inner surface of the container wall 20 (or the liquid diffusion preventing layer 1) as much as possible, This is for more effectively suppressing the decrease in the oxygen barrier property of EVOH due to moisture.
That is, the thickness of the intermediate intervening layer 9 corresponds to the distance d ₁ between the liquid diffusion preventing layer 1 and the oxygen barrier layer 3 described above. Therefore, as can be understood from the above description, it is desirable that the thickness ratio d ₁ / D is in the range of 30% or more, particularly 35 to 70% with respect to the total thickness D of the container.

Such an intermediate intervening layer 9 is provided in order to form an appropriate distance d ₁ between the liquid diffusion preventing layer 1 and the oxygen barrier layer 3, and the material thereof is not particularly limited, and is molded. It may be formed of any possible resin, and is not limited to a single layer structure, and the intermediate intervening layer 9 may be a multilayer of two or more layers.

In general, from the viewpoint of moldability and the like, a container base resin used for forming the outer surface layer 11 described later and an olefin resin (for example, polyethylene or polypropylene) used for forming the base layer 7 described above are used. The intermediate intervening layer 9 is preferably formed. Furthermore, it is more preferable in terms of cost reduction that the intermediate intervening layer 9 is formed by regrind in which scrap resin such as burrs generated when the container is molded is blended. Such regrind usually contains the scrap resin in an amount of 60% by mass or less.
Further, the intermediate intervening layer 9 may have a multilayer structure including a known oxygen-absorbing resin layer. This oxygen-absorbing resin layer supplements oxygen barrier properties, and is a layer containing an oxidizing polymer and a transition metal catalyst, as described in JP-A No. 2002-240813, etc. The oxidizing polymer is oxidized by oxygen by the action of the system catalyst, thereby absorbing oxygen and blocking the permeation of oxygen. Such an oxidizable polymer and a transition metal catalyst are described in detail in the above-mentioned JP-A-2002-240813 and the like. Olefin resins having tertiary carbon atoms (eg, polypropylene, polybutene-1, etc., or copolymers thereof), thermoplastic polyesters or aliphatic polyamides; xylylene group-containing polyamide resins; ethylenically unsaturated group-containing polymers ( For example, a polymer derived from a polyene such as butadiene). Moreover, as a transition metal type catalyst, the inorganic salt, organic acid salt, or complex salt of transition metals, such as iron, cobalt, and nickel, are typical. Such an oxygen-absorbing resin layer has a thickness of 25% or less of the thickness d ₁ of the intermediate intervening layer 9, and the intermediate intervening layer 9 is formed by the oxygen-absorbing resin layer and the regrind layer described above. The formation is more preferable in terms of cost and oxygen barrier properties.

Outer surface layer 11;
The outer surface layer 11 is formed of various thermoplastic resins for forming such a container, for example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene isophthalate or these depending on the form and use of the container. Typical examples are polyesters such as copolymers, and olefin-based resins that are also used for the formation of the above-described underlayer 7, and the container characteristics that viscous contents are contained and such contents are discharged. In view of the above, an olefin resin is optimal.

  Further, the thickness of the outer surface layer 11 is not particularly limited, but the thickness is 20 μm or more from the viewpoint of suppressing the oxygen barrier property of the oxygen barrier layer (EVOH) from being reduced by moisture from the outer surface side. Further, from the viewpoint of avoiding the problem that the thickness of the container wall 20 becomes excessively thick and the cost, lightness, etc. are unsatisfactory, the thickness is a position where the oxygen barrier layer 3 is closer to the outer surface than the inner surface. It is desirable to have a thickness of 10 to 80 μm on the condition that it is disposed on the surface.

Other layers;
In the packaging container of the present invention, the container wall 20 is formed by a multilayer structure having each layer described above as a basic layer, but improves the adhesion to the adjacent layers of the liquid diffusion prevention layer 1 and the oxygen barrier layer 3 described above, From the viewpoint of preventing delamination, it is desirable to provide adhesive resin layers (adhesive layers) on both sides of these layers 1 and 3, respectively. That is, the ethylene-vinyl alcohol copolymer (EVOH) used for forming these layers 1 and 3 has poor adhesion to other thermoplastic resins (for example, olefinic resins and polyester resins). Therefore, by providing the adhesive resin layer, interlayer adhesion can be improved and delamination can be prevented. In particular, when the liquid diffusion preventing layer 1 and the oxygen barrier layer 3 are formed of EVOH alone, it is necessary to provide an adhesive resin layer.

Adhesive resins used for forming such an adhesive resin layer are known per se. For example, a carbonyl group (> C═O) is 1 to 100 meq / 100 g resin in the main chain or side chain, particularly 10 to 100 meq / 100 g. Resin contained in the amount of resin, specifically, olefin resin graft-modified with carboxylic acid such as maleic acid, itaconic acid, fumaric acid or its anhydride, amide, ester, etc .; ethylene-acrylic acid copolymer; An ion-crosslinked olefin copolymer; an ethylene-vinyl acetate copolymer; and the like are used as the adhesive resin. The thickness of such an adhesive resin layer may be such that an appropriate adhesive force can be obtained, and is generally 0.5 to 20 μm, preferably about 1 to 8 μm.
In addition, when this packaging container has a bag-like form in which a film is bonded, an adhesive resin, for example, those generally used for dry lamination, anchor coating, and primer may be used. it can. For example, a urethane resin, a phenol resin, an epoxy resin, an alkyd resin, a melamine resin, an acrylic resin, a polyester resin, an amino resin, a fluororesin, a cellulose resin, an isocyanate resin, and the like that are known per se can be used. These adhesive resins may be used alone or may be blended if necessary. Moreover, as long as adhesion and wettability with a base material can be ensured, either water-based or solvent-based can be used. In addition to the above components, as long as the performance as an adhesive is not impaired, a curing acceleration catalyst, a filler, a softening agent, an anti-aging agent, a silane coupling agent, a stabilizer, an adhesion promoter, and leveling are known per se. An agent, an antifoaming agent, a plasticizer, an inorganic filler, a tackifying resin, or the like may be blended.

In the packaging container having such a bag-like form, the thickness of the adhesive resin layer may be usually as thin as 0.01 to 10 μm, particularly 0.1 to 5.0 μm. It is dense and has a function as the liquid diffusion preventing layer 1. Therefore, when the adhesive resin layers are provided on both sides of the liquid diffusion preventing layer 1, 70% or more of the total thickness of the adhesive resin layers on both sides and the liquid diffusion preventing layer 1 is the thickness of the liquid diffusion preventing layer 1. It is desirable to set the thickness so that the total thickness is within the range of the thickness of the liquid diffusion prevention layer 1 described above (2 μm or more, especially about 5 to 80 μm). Furthermore, when an adhesive resin layer is provided on the outer surface side of the liquid diffusion preventing layer 1 and on the inner side of the oxygen barrier layer 3, these adhesive resin layers also function as the intermediate intervening layer 9, and these adhesive resin layers taking into account the thickness, setting the thickness d ₁ of the intermediate intervening layer 9 described above.

  Furthermore, in the packaging container of the present invention comprising the above-described layers, it goes without saying that various compounding agents known per se, for example, colorants such as pigments, may be blended depending on the application.

<Characteristics, form and production of packaging container>
In the packaging container of the present invention, since the liquid diffusion preventing layer 1 is provided below the base layer 7 holding the liquid layer 5, such disappearance of the liquid layer 5 with time is effectively prevented. When the liquid layer 5 was formed and the liquid layer continuation test was performed while maintaining the atmospheric pressure, the following formula (2):
ΔF = 100 × (F ₀ −F ₁ ) / F ₀ (2)
Where
F ₀ is the coverage F of the liquid layer 5 one day after the start of the test,
F ₁ is the coverage F of the liquid layer 5 after 14 days from the start of the test.
Is reduced to 40% or less, particularly 20% or less, and further 10% or less. That is, not only immediately after the liquid layer 5 is formed, but also when the liquid layer continuity test is performed after a long time has elapsed since the liquid layer 5 was formed, the coating reduction rate ΔF suppressed as described above is obtained. Show.
Therefore, in the present invention, it is possible to stably exhibit surface characteristics by the liquid layer 5 over a long period of time, and slipperiness with respect to various viscous contents described later is maintained over a long period of time. It can be discharged quickly.

  Further, the liquid diffusion preventing layer 1 contains an ethylene-vinyl alcohol copolymer (EVOH), and further, an oxygen barrier layer 3 containing EVOH is formed apart from the liquid diffusion preventing layer 1. Therefore, the oxygen barrier property of the oxygen barrier layer 3 (EVOH) due to the influence of moisture can be effectively avoided, and the container is filled with a viscous content liquid containing moisture as well as the state of the empty container. Even after this, excellent oxygen barrier properties are stably exhibited over a long period of time, and it is possible to effectively avoid the oxidative deterioration of the viscous contents and the decrease in the flavor of the contents due to the oxidative deterioration.

The packaging container of the present invention can have various forms, and a liquid that forms the liquid layer 5 can be selected according to the form to exhibit desired surface characteristics.
For example, the shape of the container is not particularly limited, and may have a shape corresponding to the container material, such as a cup or cup shape, a bottle shape, a bag shape (pouch), a syringe shape, an acupoint shape, or a tray shape, and is stretch-molded. May be.
Such a container is formed by a method known per se in the form of a layered structure including the above-mentioned layers, and this is applied to a film by heat sealing, vacuum forming such as plug assist molding, blow molding or the like. By applying the post-processing to the form of a container and further applying the liquid for forming the liquid layer 5 to the surface of the underlayer 7 on the inner surface by means of spraying, dipping or the like according to the form, the liquid layer 5 may be in the form of a multi-layered container having an inner surface.
Of course, if the liquid for forming the liquid layer 5 is internally added to the resin for forming the base layer 7, the operation of applying the liquid can be omitted. In the blow container, a thin film of the liquid layer 5 can be formed evenly over the entire surface of the foundation layer 7 (inner surface of the container) by supplying the liquid simultaneously with the blow.

Since the above-described packaging container of the present invention can sufficiently exhibit the surface characteristics of the liquid layer 5, in particular, a viscous content having a viscosity (25 ° C.) of 100 mPa · s or more, for example, ketchup, aqueous paste Most suitable as a container filled with viscous contents such as honey, various sauces, mayonnaise, mustard, dressing, jam, chocolate syrup, milky lotion, liquid detergent, shampoo, rinse and the like. That is, by forming the liquid layer 5 with an appropriate liquid according to the type of contents, the contents can be quickly discharged without being attached to the inner wall of the container by inclining or inverting the container. .
For example, ketchup, various sauces, honey, mayonnaise, mustard, jam, chocolate syrup, milky lotion, etc. are hydrophilic substances that contain moisture. Oily liquids approved as food additives such as oil are preferably used.
Furthermore, the above-described oxidative deterioration of the contents can be effectively prevented.

The present invention will be described in the following experimental examples.
In addition, the various measurement methods performed in the following experimental examples and the like, measurement methods for physical properties, etc., and resins used for molding the packaging container (bottle) are as follows.

1. Measurement of the layer structure of the container;
The layer structure in the horizontal section of the trunk at a position 50 mm from the bottom of the packaging container (bottle) formed by the method described later was observed with a polarizing microscope, and the thickness of each layer was determined. The configurations at 0 °, 90 °, 180 °, and 270 ° with respect to the cross section were observed, and the average value in the four directions was taken as the layer configuration of the container. From the obtained value, the ratio (d ₁ / D) of the distance d ₁ between the liquid diffusion preventing layer (A) and the oxygen barrier resin layer (B) with respect to the total thickness D, and the oxygen barrier resin layer (B The thickness ratio of the liquid diffusion preventing layer (A) relative to) was calculated.

2. Oxygen permeability measurement;
In order to evaluate the oxygen permeability of the packaging container (bottle) molded by the method described later, 2 mL of distilled water was put into the bottle, and the polyethylene (inner layer) / It was heat-sealed with a lid made of aluminum foil / polyester (outer layer), sealed, and stored at 30 ° C.-80% RH for 14 days. The oxygen concentration in the container after 14 days was measured using gas chromatography (GC-14A, manufactured by Shimadzu Corporation). The smaller the oxygen concentration in the container, the better the oxygen barrier property.

3. Measurement of liquid layer coverage;
Using a packaging container (bottle) produced by the method described later, the liquid layer formed on the inner surface of the container is recovered with 30 mL of a solvent (heptane) miscible with the liquid layer, concentrated using an evaporator, and then the residue Was transferred to an evaporating dish and the weight of the liquid layer components was determined. The obtained weight was divided by the area of the inner surface of the container to obtain the liquid layer coating amount (g / m ² ) on the inner surface of the bottle. The smaller this value is, the thinner the liquid layer is formed on the inner surface of the container.

4). Measurement of the coverage of the liquid layer;
A test piece of 10 mm × 60 mm was cut out from the body of a packaging container (bottle) produced by the method described later. Using a solid-liquid interface analysis system DropMaster700 (manufactured by Kyowa Interface Chemical Co., Ltd.) under the condition of 23 ° C. and 50% RH, the test sample was fixed so that the inner layer was on top, and 3 μL of pure water was placed on the test piece. The water contact angle θ was measured. Using the obtained water contact angle, the coverage F of the liquid layer on the inner surface of the container wall was determined from the following formula (1).
F = (cos θ−cos θ _B ) / (cos θ _A −cos θ _B ) (1)
Where θ is the water contact angle at the bottle inner surface,
θ _A is the water contact angle on the liquid forming the liquid layer,
θ _B is a water contact angle on a single plastic forming the bottle inner surface underlayer.
In obtaining the liquid layer coverage F, the following water contact angle values were used as the values of θ _A and θ _B.
θ _B : 100.1 °
(Value in the high pressure method low density polyethylene (MFR = 0.3) simple substance)
θ _A : 80.3 °
(Value on medium chain fatty acid triglyceride (liquid))
In addition, when the liquid layer coverage F is 0, it indicates that no liquid layer is formed, and when it is 1, it indicates that the resin is completely covered with the liquid without being exposed on the surface. Yes.
In order to maximize the performance of the liquid layer, the liquid layer coverage F is preferably close to 1.

5. Liquid layer continuity test and calculation of liquid layer coating reduction rate ΔF;
A packaging container (bottle) produced by the method described later was stored at 22 ° C. and 60% RH (under atmospheric pressure) for a predetermined period. Using the container after a predetermined time, the above-described liquid layer coverage was measured.
In particular, the coating reduction rate ΔF was determined from the following formula (2) from the coverage F of the liquid layer after 1 day and after 14 days.
ΔF = 100 × (F ₀ −F ₁ ) / F ₀ (2)
Where
F ₀ is the coverage F of the liquid layer one day after the start of the test,
F ₁ is the coverage F of the liquid layer after 14 days from the start of the test.
Here, the smaller the coating reduction rate ΔF, the higher the sustainability of the liquid layer.

6). Measurement of sliding speed of contents having viscosity (sliding speed measurement);
A test piece of 20 mm × 70 mm was cut out from the trunk of a packaging container (bottle) produced by the method described later. Using a solid-liquid interface analysis system DropMaster700 (manufactured by Kyowa Interface Chemical Co., Ltd.) under the condition of 23 ° C. and 50% RH, the test sample was fixed so that the inner layer was on top, and the content having a consistency of 70 mg was obtained. The specimen was placed on a test piece, and the sliding behavior at an inclination angle of 45 ° was photographed with a camera, the sliding behavior was analyzed, and the sliding speed was calculated from a moving distance-time plot. This sliding speed was used as an index of sliding ability. The larger the value of the sliding speed, the better the sliding characteristics of the viscous content. The contents used are as follows. In addition, as a viscosity of the contents, a value measured at 25 ° C. using a tuning fork type vibration viscosity system SV-10 (manufactured by A & D Co., Ltd.) is also shown.
The viscous content used;
QP half (manufactured by QP Corporation, viscosity = 1260 mPa · s)
Favorite sauce (Otafuku Sauce Co., Ltd., viscosity = 560 mPa · s)

<Liquid for forming a liquid layer>
Medium chain fatty acid triglyceride (MCT)
Surface tension: 28.8 mN / m (23 ° C.)
Viscosity: 33.8 mPa · s (23 ° C)
Boiling point: 210 ° C or higher Flash point: 242 ° C (reference value)
In addition, the surface tension of the liquid used the value measured at 23 degreeC using the solid-liquid interface analysis system DropMaster700 (made by Kyowa Interface Science Co., Ltd.). In addition, the density of the liquid required for the liquid surface tension measurement used the value measured at 23 degreeC using the density specific gravity meter DA-130 (made by Kyoto Electronics Industry Co., Ltd.). Further, the viscosity of the lubricating liquid showed a value measured at 23 ° C. using a tuning fork type vibration viscometer SV-10 (manufactured by A & D Co., Ltd.).

<Inner surface underlayer forming resin>
Low density polyethylene (LDPE)
MFR; 0.3 g / 10 min (190 ° C., 2.16 Kg)
Density: 0.922 g / cm ³
<Liquid diffusion prevention layer forming resin>
Ethylene-vinyl alcohol copolymer (EVOH)
Density: 1.20 g / cm ³
Tg = 60 ° C
Blend of ethylene-vinyl alcohol copolymer and polyolefin (composition comprising EVOH / PO blend, EVOH / modified polyolefin = 7/3 (weight ratio))
<Adhesive layer forming resin>
Acid anhydride-modified polyethylene <Oxygen barrier layer forming resin>
Ethylene-vinyl alcohol copolymer (EVOH)
Density 1.20 g / cm ³
Tg = 60 ° C
Blend of ethylene-vinyl alcohol copolymer and polyolefin (composition comprising EVOH / PO blend, EVOH / modified polyolefin = 7/3 (weight ratio))
<Polyolefin resin layer forming resin>
Low density polyethylene (LDPE)
MFR; 0.3 g / 10 min (190 ° C., 2.16 Kg)
Density: 0.922 g / cm ³
<Resin for forming outer layer>
Low density polyethylene (LDPE)
MFR; 0.3 g / 10 min (190 ° C., 2.16 Kg)
Density: 0.922 g / cm ³

<Experimental example 1>
Low density polyethylene (LDPE) as the inner surface underlayer forming resin, ethylene-vinyl alcohol copolymer (EVOH) as the liquid diffusion preventing layer forming resin, anhydride-modified polyethylene as the adhesive layer forming resin, and oxygen barrier layer forming Ethylene-vinyl alcohol copolymer (EVOH) as the resin, low density polyethylene (LDPE) as the resin for forming the polyolefin resin layer existing between the liquid diffusion preventing layer and the oxygen barrier layer, and low density polyethylene as the resin for forming the outer surface layer (LDPE), respectively, are supplied to an extruder, and medium chain fatty acid triglyceride (MCT) is supplied by a pump as a liquid layer forming material for coating the innermost resin layer of the packaging container. Extrusion of molten parison with multi-layer die head at ℃ By blow molding, to produce inner volume 500 g, the multilayer bottle of weight 20g. The layer configuration of this bottle (configuration of the resin layer) was measured by the method described above. The layer configuration and the ratio of each layer thickness are as follows.
Layer structure;
Inner surface underlayer (24) / Adhesive layer (3) / Liquid diffusion prevention layer (4) / Adhesive layer (2) / Polyolefin resin layer (50) / Adhesive layer (3) / Oxygen barrier layer (4) / Adhesive Layer (2) /
External layer (8)
Overall thickness: 510 μm
Here, the value in parentheses is the thickness ratio (%) of each layer to the total thickness.
Using the produced bottle, oxygen permeability measurement, liquid layer coating amount measurement, liquid layer continuity test, and sliding speed measurement were performed. The results are summarized in Table 1.

<Experimental example 2>
Resin composition comprising 95/5 weight ratio of low density polyethylene (LDPE) and medium chain fatty acid triglyceride (MCT) as inner surface underlayer forming resin, ethylene-vinyl alcohol copolymer as liquid diffusion preventing layer forming resin (EVOH), an acid-modified polyethylene as an adhesive layer forming resin, an ethylene-vinyl alcohol copolymer (EVOH) as an oxygen barrier layer forming resin, and a polyolefin resin present between the liquid diffusion preventing layer and the oxygen barrier layer Pellets of low density polyethylene (LDPE) as the layer forming resin and low density polyethylene (LDPE) as the outer surface layer forming resin are respectively supplied to the extruder, and the molten parison is extruded by a multilayer die head at a temperature of 210 ° C., mold temperature Internal capacity 500 g, weight 20 by a known direct blow molding method at 22 ° C. The multi-layer bottle was produced. The layer structure of this bottle and the ratio of the thickness of each layer are as follows.
Layer structure;
Inner surface underlayer (23) / adhesive layer (3) / liquid diffusion preventing layer (4) / adhesive layer (2) / polyolefin resin layer (48) / adhesive layer (3) / oxygen barrier layer (6) / adhesive Layer (3) /
External layer (8)
Overall thickness: 515 μm
Here, the value in parentheses is the thickness ratio (%) of each layer to the total thickness.
Using the produced bottle, oxygen permeability measurement, liquid layer coating amount measurement, liquid layer continuity test, and sliding speed measurement were performed. The results are summarized in Table 1.

<Experimental example 3>
A multilayer bottle was produced in the same manner as in Experimental Example 1 except that the composition ratio of each layer was changed. The layer structure of this bottle and the ratio of the thickness of each layer are as follows.
Layer structure;
Inner surface underlayer (15) / adhesive layer (3) / liquid diffusion preventing layer (6) / adhesive layer (2) / polyolefin resin layer (62) / adhesive layer (2) / oxygen barrier layer (3) / adhesive Layer (1) /
External layer (6)
Overall thickness: 550 μm
Here, the value in parentheses is the thickness ratio (%) of each layer to the total thickness.
Using the produced bottle, oxygen permeability measurement, liquid layer coating amount measurement, liquid layer continuity test, and sliding speed measurement were performed. The results are summarized in Table 1.

<Experimental example 4>
A multilayer bottle was produced in the same manner as in Experimental Example 1, except that the resin for forming the liquid diffusion preventing layer was changed to a blend of ethylene-vinyl alcohol copolymer and polyolefin (EVOH / PO blend) and the composition ratio of each layer was changed. . The layer structure of this bottle and the ratio of the thickness of each layer are as follows.
Layer structure;
Inner surface underlayer (34) / adhesive layer (3) / liquid diffusion preventing layer (10) / adhesive layer (3) / polyolefin resin layer (31) / adhesive layer (3) / oxygen barrier layer (4) / adhesive Layer (4)
/ Outer surface layer (8)
Overall thickness: 585 μm
Here, the value in parentheses is the thickness ratio (%) of each layer to the total thickness.
Using the produced bottle, oxygen permeability measurement, liquid layer coating amount measurement, liquid layer continuity test, and sliding speed measurement were performed. The results are summarized in Table 1.

<Experimental example 5>
Low density polyethylene (LDPE) as the inner surface underlayer forming resin, ethylene-vinyl alcohol copolymer / polyolefin blend (EVOH / PO blend) as the liquid diffusion prevention layer forming resin, and ethylene as the oxygen barrier layer forming resin -Blend of vinyl alcohol copolymer and polyolefin (EVOH / PO blend), Low density polyethylene (LDPE) as a resin for forming polyolefin resin layer existing between liquid diffusion preventing layer and oxygen barrier layer, forming outer layer Low density polyethylene (LDPE) pellets are supplied to the extruder as resin for use, and medium-chain fatty acid triglyceride (MCT) is used as a liquid layer forming material for coating the innermost resin layer of the packaging container. And a parison melted by a multilayer die head with a temperature of 210 ° C. Extrusion, by a known direct blow molding method at a die temperature of 22 ° C., to produce inner volume 500 g, the multilayer bottle of weight 20g. The layer structure of this bottle and the ratio of the thickness of each layer are as follows.
Layer structure;
Inner surface underlayer (26) / Liquid diffusion prevention layer (10) / Polyolefin resin layer (52) /
Oxygen barrier layer (8) / outer surface layer (4)
Overall thickness: 520 μm
Here, the value in parentheses is the thickness ratio (%) of each layer to the total thickness.
Using the produced bottle, oxygen permeability measurement, liquid layer coating amount measurement, liquid layer continuity test, and sliding speed measurement were performed. The results are summarized in Table 1.

<Experimental example 6>
A multilayer bottle was produced in the same manner as in Experimental Example 5 except that the composition ratio of each layer was changed. The layer structure of this bottle and the ratio of the thickness of each layer are as follows.
Layer structure;
Inner surface underlayer (27) / Liquid diffusion prevention layer (6) / Polyolefin resin layer (58) / Oxygen barrier layer (4) / Outer surface layer (5)
Overall thickness: 510 μm
Here, the value in parentheses is the thickness ratio (%) of each layer to the total thickness.
Using the produced bottle, oxygen permeability measurement, liquid layer coating amount measurement, liquid layer continuity test, and sliding speed measurement were performed. The results are summarized in Table 1.

<Experimental example 7>
A multilayer bottle was produced in the same manner as in Experimental Example 5 except that the composition ratio of each layer was changed. The layer structure of this bottle and the ratio of the thickness of each layer are as follows.
Layer structure;
Inner surface underlayer (21) / Liquid diffusion prevention layer (6) / Polyolefin resin layer (14) / Oxygen barrier layer (5) / Outer surface layer (54)
Overall thickness: 535 μm
Here, the value in parentheses is the thickness ratio (%) of each layer to the total thickness.
Using the produced bottle, oxygen permeability measurement, liquid layer coating amount measurement, liquid layer continuity test, and sliding speed measurement were performed. The results are summarized in Table 1.

<Experimental Example 8>
A resin composition comprising a weight ratio of low-density polyethylene (LDPE) and medium chain fatty acid triglyceride (MCT) of 97/3 as an inner surface underlayer forming resin, and an ethylene-vinyl alcohol copolymer as a liquid diffusion preventing layer forming resin (EVOH), an anhydride-modified polyethylene as an adhesive layer forming resin, and a low-density polyethylene (LDPE) pellet as an outer surface layer forming resin are each fed to an extruder, and a molten parison is extruded by a multilayer die head at a temperature of 210 ° C. A multilayer bottle having an internal volume of 500 g and a weight of 20 g was produced by a known direct blow molding method at a mold temperature of 22 ° C. The layer structure of this bottle and the ratio of the thickness of each layer are as follows.
Layer structure;
Inner surface underlayer (15) / Adhesive layer (2) / Liquid diffusion prevention layer (5) / Adhesive layer (2) / Outer surface layer (76)
Overall thickness: 420 μm
Here, the value in parentheses is the thickness ratio (%) of each layer to the total thickness.
Using the produced bottle, oxygen permeability measurement, liquid layer coating amount measurement, liquid layer continuity test, and sliding speed measurement were performed. The results are summarized in Table 1.

<Experimental Example 9>
As a resin for forming an inner surface underlayer, a resin composition having a weight ratio of low-density polyethylene (LDPE) and medium-chain fatty acid triglyceride (MCT) of 97/3, low-density polyethylene (LDPE) as a resin for forming a polyolefin-based resin layer, Pellets of acid anhydride-modified polyethylene as the adhesive layer forming resin, ethylene-vinyl alcohol copolymer (EVOH) as the oxygen barrier layer forming resin, and low density polyethylene (LDPE) as the outer surface layer forming resin are respectively fed to the extruder. The melted parison was extruded by a multilayer die head having a temperature of 210 ° C., and a multilayer bottle having an internal volume of 500 g and a weight of 20 g was produced by a known direct blow molding method at a mold temperature of 22 ° C. The layer structure of this bottle and the ratio of the thickness of each layer are as follows.
Layer structure;
Inner surface underlayer (15) / Polyolefin resin layer (60) / Adhesive layer (2) / Oxygen barrier layer (5) / Adhesive layer (3) / Outer surface layer (15)
Overall thickness: 400 μm
Here, the value in parentheses is the thickness ratio (%) of each layer to the total thickness.
Using the produced bottle, oxygen permeability measurement, liquid layer coating amount measurement, liquid layer continuity test, and sliding speed measurement were performed. The results are summarized in Table 1.

From the results of the measurement of the liquid layer coating amount and the sliding test in Table 1, in Experimental Examples 1 to 8 provided with the liquid diffusion preventing layer, it can be confirmed that the liquid layer is coated at 0.5 g / m ² or more. It can be seen that the value of the sliding speed of the half is 4 mm / min or higher, and the value of the otafuku favorite sauce is 9 mm / min or higher, indicating high sliding performance. On the other hand, in Experimental Example 9 in which no liquid diffusion preventing layer is provided, the liquid layer has a coating amount of 0.2 g / m ² or less, the value of the sliding speed of the QP half is 0.2 mm / min, It can be seen that the sliding property is low at 0.1 mm / min.
Also, from the results of the liquid layer continuity test, in Experimental Examples 1 to 8 in which the liquid diffusion preventing layer was provided, the coverage after 14 days was 0.6 or more and the coating reduction rate ΔF was 20% or less. I understand. On the other hand, in Experimental Example 9 in which the liquid diffusion preventing layer is not provided, it can be seen that the coverage ratio is rapidly reduced to 0.34 at the stage one day after the test.
Further, from the results of the oxygen permeability measurement, in Experimental Example 8 in which the oxygen barrier resin layer is not provided, the oxygen concentration is very high as 1% or more and the oxygen barrier property is very poor. In the provided experimental examples 1 to 7 and 9, it can be seen that the barrier property is improved when the oxygen concentration is less than 1%. Among them, in Experimental Examples 1 to 6 in which the ratio d ₁ / D of the distance d ₁ between the oxygen barrier resin layer and the liquid diffusion preventing layer to the total thickness D of the container is 30% or more, the oxygen concentration is 0 It can be confirmed that it shows a very good value of .4% or less.
From these facts, the liquid layer is formed on the surface, and the liquid diffusion preventing layer is arranged on the inner surface side of the oxygen barrier resin layer, so that it is excellent in the sliding property of the viscous contents and the durability of the liquid layer. It can be seen that a high oxygen barrier property can be simultaneously imparted to the packaging container.

1: Liquid diffusion prevention layer 3: Oxygen barrier layer 5: Liquid layer 7: Underlayer 9: Intermediate intervening layer 11: Outer surface layer

Claims (4)

A plastic packaging container in which a content containing moisture having viscosity is stored ,
A liquid layer of 0.2 to 50 g / m ^{2 of} an oily liquid is formed on the surface in contact with the contents,
The container wall of the packaging container functions as a base layer serving as a base of the liquid layer, a liquid diffusion preventing layer provided adjacent to the base layer and preventing permeation and diffusion of oily liquid from the liquid layer. The first oxygen barrier resin layer and the first oxygen barrier resin layer include a second oxygen barrier resin layer formed at an interval from the first oxygen barrier resin layer. Between the two oxygen barrier resin layers, an intermediate intervening layer is provided for defining the distance between the two layers.
The underlayer is made of an olefin resin having a density of less than 1.0 g / cm ^3, and the oil liquid penetrates from the liquid layer into the underlayer,
Each of the first and second oxygen barrier resin layers contains 60% by mass or more of an ethylene-vinyl alcohol copolymer having a density of 1.0 g / cm ³ or more and a glass transition point Tg of 35 ° C. or more. Layer,
A plastic packaging container having a ratio of d ₁ / D of 30 to 70%, where d _{1 is} the thickness of the intermediate intervening layer and D is the total thickness of the container.   2. The plastic packaging container according to claim 1, wherein the thickness of the first oxygen barrier resin layer functioning as the liquid diffusion preventing layer is in the range of 50 to 300% of the thickness of the second oxygen barrier resin layer. . The liquid layer is a plastic packaging container according to claim 1 or 2 is formed in an amount of 0.2 to 10 g / ^{m 2.}   The plastic packaging container according to claim 1, wherein the intermediate intermediate layer includes a polyolefin resin layer.

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