WO2020004287A1 - Direct-blow empty bottle with liquid lubricant layer on inner surface, and bottled oil-in-water type emulsified food - Google Patents

Abstract

The present invention provides a direct-blow empty bottle for storing a water-containing substance and having a liquid lubricant layer on the inner surface of the bottle, wherein a bottle wall has an oxygen barrier layer having a liquid diffusion prevention function. The direct-blow empty bottle is capable of effectively suppressing oxidative deterioration of the liquid lubricant layer formed on the inner surface of the bottle, and of stably improving the lubricity of the water-containing substance by the liquid lubricant layer over a long period of time together with suppression of permeation of the lubricant into the bottle. The present invention is characterized in that the direct-blow empty bottle to be used by being filled with a water-containing substance is produced by forming a liquid lubricant coating layer formed by a liquid lubricant for improved lubricity of the water-containing substance, an inner-surface resin layer serving as a base of the coating layer, a liquid diffusion prevention oxygen barrier layer for preventing diffusion of the lubricant, an oxygen absorption layer, an oxygen barrier layer, and an outer-surface resin layer in said order starting from the inner surface toward the outer surface, wherein the inner-surface resin layer is formed using a low-density polyethylene, and the inner-surface resin layer is formed to a thickness of 15 to 45 mass% with respect to the total mass of the bottle excluding the lubricant coating layer.

Description

Direct blow empty bottles with a lubricant coating layer on the inside and bottled oil-in-water emulsified foods

The present invention particularly relates to a direct blow empty bottle in which a viscous hydrated substance such as various dressings, mayonnaise, and mayonnaise-like foods is filled and used as a content.

Plastic is widely used in various applications because it is easy to mold and can be easily molded into various forms. In particular, a direct blow bottle in which the inner surface of the container wall is formed of an olefin resin such as low-density polyethylene is a container for accommodating viscous slurry-like or paste-like contents from the viewpoint that the contents are easily squeezed out. It is preferably used as

In the case of a bottle containing viscous contents, when the contents are stored in an inverted state in order to quickly discharge the contents or to completely use the contents without leaving them in the bottle. There are many. Therefore, when the bottle is inverted, it is desired that the viscous contents fall quickly without adhering and remaining on the inner wall surface of the bottle.

ボ ト ル As a bottle satisfying such a requirement, for example, Patent Documents 1 to 3 propose a plastic container having a liquid layer formed on an inner surface in contact with the contents. This container has succeeded in significantly improving the slipperiness with respect to the contents by forming a liquid layer (lubricating liquid layer) of a liquid immiscible with the contents as compared with the conventionally known ones. By inverting or tilting the container, the contents can be quickly discharged out of the container without adhering or remaining on the inner wall of the container.

However, in a structure having a lubricating liquid layer on the surface, properties such as excellent slipperiness due to the liquid layer are lost over time. For example, after several days from manufacture, the properties imparted by the liquid layer are significantly reduced. There is a problem of lowering.

As a multilayer structure container in which the above-mentioned problem has been solved, Patent Literature 4 has a lubricant layer on the surface of a plastic base layer and suppresses the diffusion of a lubricant under the base layer. Alternatively, there has been proposed a multilayer container provided with a liquid diffusion preventing layer for blocking.
However, such a multilayered container may not be able to obtain sufficient oxygen barrier properties. That is, since the liquid diffusion preventing layer can be formed of a typical ethylene-vinyl alcohol copolymer as an oxygen barrier resin, it is possible to originally secure sufficient oxygen barrier properties. Since such a liquid diffusion preventing layer is formed at a position close to the inner surface of the container, when the content is a water-containing substance, the water diffusion preventing layer depends on the ethylene content of the ethylene / vinyl alcohol copolymer in the liquid diffusion preventing layer. However, there is still room for improvement in that it may be deteriorated due to the influence of and may not be able to exhibit sufficient oxygen barrier properties. In addition, the decrease in the oxygen barrier property causes not only the oxidative deterioration of the contents but also the oxidative deterioration of the lubricating liquid layer formed on the inner surface of the container. There is also a problem that the effect cannot be sufficiently exhibited.

Therefore, as a result of research on a type of container in which a liquid layer is formed on the inner surface of the container, Patent Literature 5 discloses a container in which a liquid film (lubricating liquid layer) of an oily liquid is formed on the inner surface. It has been proposed to provide two oxygen barrier layers comprising ethylene vinyl alcohol having a certain density and a glass transition point at a certain distance from each other. That is, of the two oxygen barrier layers, the oxygen barrier layer (first oxygen barrier resin layer) provided on the side closer to the inner surface resin layer serving as the base of the liquid layer exhibits the oxygen barrier property and the liquid diffusion preventing function, The oxygen barrier layer (second oxygen barrier resin layer) located on the side away from the inner resin layer has a layer structure that mainly exhibits oxygen barrier properties. That is, the first oxygen barrier resin layer effectively prevents the liquid formed on the inner surface resin layer from permeating and diffusing, and at the same time, develops the oxygen barrier property. Even if the barrier property is deteriorated, a decrease in the oxygen barrier property can be effectively avoided because the second oxygen barrier resin layer is present.

However, even with such a layer configuration, there is a need to further suppress the oxidative deterioration of the lubricating liquid layer existing on the inner surface of the container and to further maintain the effect of improving the lubricating liquid layer's lubricity.

WO2014 / 010534 WO2014 / 123217 Patent No. 622022 WO2014 / 188883 Patent No. 6237154

Therefore, an object of the present invention is to provide a direct blow bottle containing a water-containing substance and having a lubricating liquid layer on the inner surface of the bottle, wherein the bottle wall has an oxygen barrier layer having a liquid diffusion preventing function, and Oxidative degradation of the lubricating liquid layer provided on the inner surface of the bottle is effectively suppressed, and in combination with suppression of the penetration of the lubricating liquid into the bottle, the lubricating liquid layer stably improves the lubricity of water-containing substances over a long period of time. An object of the present invention is to provide a direct blow empty bottle that can be developed.

That is, according to the present invention, in a direct blow empty bottle used by being filled with a water-containing substance,
A lubricating liquid coating layer formed of a lubricating liquid for improving lubricity with respect to the water-containing substance, an inner resin layer serving as a base of the coating layer, and a liquid diffusion preventing oxygen for preventing diffusion of the lubricating liquid The barrier layer, the oxygen absorption layer, the oxygen barrier layer and the outer resin layer are formed in this order from the inner surface to the outer surface,
The water-containing substance is an oil-in-water emulsified food having a viscosity of 30 Pa · s or more,
The inner resin layer is formed of low-density polyethylene, and the inner resin layer is formed to have a thickness of 15 to 45% by mass relative to the total mass of the bottle excluding the lubricant coating layer. A direct blow empty bottle is provided.
According to the present invention, there is also provided a bottled oil-in-water type emulsified food filled in a direct blow empty bottle.

In the direct blow empty bottle of the present invention, the following aspects are suitably adopted.
(1) The liquid diffusion preventing oxygen barrier layer is made of an ethylene / vinyl alcohol copolymer.
(2) The liquid diffusion preventing oxygen barrier layer contains an ethylene / vinyl alcohol copolymer, low density polyethylene, and a compatibilizer.
(3) The lubricant coating layer is formed with a thickness of 1.0 to 35.0 g / m ² .
(4) An oily liquid is used as the lubricating liquid.
(5) Edible oil is used as the oily liquid.
(6) The vegetable oil contained in the emulsified food is selected as the edible oil.
(7) The inner resin layer is free of a lubricant, or the amount of the lubricant added is smaller than that of the outer resin layer.
(8) Part of the lubricating liquid has penetrated into the inner resin layer.

The direct blow empty bottle of the present invention is used for an application in which a hydrated substance is filled as a content, and a lubricant coating layer formed by a lubricant for improving lubricity with respect to the hydrated substance has a bottle. The bottle wall, which is provided on the inner surface and has such a lubricating liquid coating layer on the inner surface, has an inner resin layer, a liquid diffusion preventing oxygen barrier layer, an oxygen absorption layer, an oxygen barrier And an outer resin layer.
As understood from such a basic layer structure, in the direct blow empty bottle of the present invention, the liquid diffusion preventing oxygen barrier layer is disposed below the inner resin layer which is the base of the lubricating liquid coating layer. . Therefore, the penetration and diffusion of the lubricating liquid forming the lubricating liquid coating layer into the bottle are effectively suppressed, and the temporal disappearance of the lubricating liquid coating layer is effectively avoided.

The liquid diffusion preventing oxygen barrier layer contains an ethylene / vinyl alcohol copolymer exhibiting oxygen barrier properties, and the outer surface side of the liquid diffusion preventing oxygen barrier layer has a function of preventing permeation of oxygen. Having two layers, namely, an oxygen absorbing layer and an oxygen barrier layer. Therefore, even when the oxygen barrier property of the liquid diffusion preventing oxygen barrier layer disposed at a position close to the content that is a water-containing substance is reduced by moisture, the above-described oxygen absorption layer and oxygen barrier layer are present. Therefore, sufficient oxygen barrier properties are maintained. As a result, oxidation degradation of not only the contents but also the lubricating liquid forming the lubricating liquid coating layer is effectively prevented, and as a result, the lubricity with respect to the contents (water-containing substance) is stably exhibited for a long period of time.
Further, since the inner resin layer is formed of low-density polyethylene, it exhibits appropriate permeability and wettability to a lubricating liquid. Such an inner resin layer is formed to have a thickness of 15 to 45% by mass with respect to the total mass of the bottle excluding the lubricant coating layer. Therefore, the lubricating liquid coating layer is widely distributed so as to cover the entire inner resin layer, and the lubricating liquid permeates into the inner resin layer in an appropriate amount. It does not fall off and is kept stable.

As described above, in the present invention, the loss of the lubricating liquid coating layer due to permeation into the bottle, the deterioration of the properties due to oxidative deterioration are effectively prevented, and the falling off from the inner surface of the bottle is also effectively prevented. In this way, the lubricating liquid coating layer stably exhibits a decrease in lubricity, and the viscous hydrated substance can always be smoothly discharged.

The direct-blow empty bottle of the present invention, which is used by being filled with a hydrated substance, has a lubricating liquid coating layer, an inner resin layer, a liquid diffusion preventing oxygen barrier layer, a regrind layer, from the inner surface side to the outer surface side of the bottle. It has an oxygen absorbing layer, an oxygen barrier layer and an outer resin layer.

<Hydrous substances>
The water-containing substance to be filled as the content is not particularly limited as long as it contains water, and may be various foods, cosmetics, pharmaceuticals, and the like. For example, oil-in-water emulsified foods such as various dressings, mayonnaise or mayonnaise-like foods, and oil-in-water emulsified foods containing ingredients are suitable.
The hydrous substance in which the effect of the present invention is maximized is, of course, a viscous substance. For example, the viscosity at 25 ° C. of the above-mentioned various hydrous substances is 30 Pa · s or more. Is a substance.
In particular, in the present invention, in order to be able to most effectively avoid the deterioration of food quality due to the lubricating liquid described below, mayonnaise, mayonnaise-like food, oil-in-water emulsion such as oil-in-water emulsion food containing ingredients. Food is most suitable as a hydrated substance to be filled into empty bottles.

<Lubricant coating layer>
The lubricating liquid coating layer provided on the inner surface of the above-described empty bottle of the present invention is a lubricating liquid that improves lubricity with respect to the above-mentioned hydrated substance, that is, a liquid that exhibits water repellency with respect to the hydrated substance. This is a layer formed by applying to a layer (that is, the inner surface of an empty bottle).

Such lubricating liquids are typically fluorinated surfactants, silicone oils, or various oily liquids, such as fatty acid triglycerides, edible oils, etc., provided that they are high boiling liquids (for example, having a boiling point of 200 ° C. or higher). It is a target. In particular, when food is used as the water-containing substance to be filled in the bottle, an oily liquid that does not adversely affect the human body or the flavor of the food, particularly an edible oil, is preferably used.
The above-mentioned edible oils include soybean oil, rapeseed oil, olive oil, rice oil, corn oil, rapeseed oil, sesame oil, palm oil, castor oil, avocado oil, coconut oil, almond oil, walnut oil, maize oil, etc. Edible vegetable oils and fats, and MCT (medium chain fatty acid triglyceride). In particular, when the oil-in-water emulsified food is filled as the content, the edible vegetable oils and fats contained in such an oil-in-water emulsified food, even when discharged together with such an emulsified food, its flavor, etc. It is optimal in that it does not impair the quality. For example, it is preferable to use edible vegetable oils and fats contained in mayonnaise and mayonnaise-like foods as the lubricating liquid.

In the present invention, the application of the lubricating liquid to the inner resin layer surface is performed by spraying the lubricating liquid supply nozzle inserted into the empty bottle after the direct blow molding.
Thus, the lubricating liquid coating layer usually has a liquid amount of 1.0 to 35.0 g / m ² , preferably 1.5 to 25.0 g / m ² , and more preferably 5 to 20.0 g / m ^2. Is formed in a thickness falling within the range. That is, if the amount of the liquid is small, sufficient lubricity cannot be imparted to the hydrated substance as the content, while if the amount of the liquid is excessively large, the liquid easily falls off and the like. This is because there is a possibility that the fluctuation of the diameter becomes large, and it becomes impossible to secure stable lubrication.

In addition, as described later, since a part of the lubricating liquid coated on the surface of the inner resin layer permeates into the inner resin layer with the passage of time, a lab test is performed in advance, and such a lubricating liquid is used. In consideration of penetration, the amount of the lubricating liquid applied by spraying is adjusted so as to obtain a coating layer having the above thickness.

Incidentally, there is also known a method in which a lubricating liquid is blended in a resin composition for forming an inner resin layer, and a lubricating liquid layer is formed by bleeding the lubricating liquid from the inner resin layer. It is difficult to adjust the thickness of the lubricating liquid layer on the surface (the amount of the lubricating liquid). For this reason, in the present invention, means for coating a lubricating liquid on the inner resin layer by spraying is adopted.

<Inner resin layer>
As understood from the above description, the inner resin layer that forms the inner surface of the direct blow empty bottle of the present invention is a layer serving as a base of the above-mentioned lubricating liquid coating layer, and therefore has a high lubricating liquid. It is necessary that the lubricating liquid has a property of adequately penetrating while exhibiting wettability.
From such a viewpoint, in the present invention, the inner resin layer is formed of low-density polyethylene.

That is, low-density polyethylene (LDPE) is a polyethylene having a density of 0.91 to 0.93 g / cm ³ , and the inner resin layer formed using such low-density polyethylene has the above-described properties. This is a layer suitable as a base for the lubricating liquid coating layer.
For example, in a medium-density or high-density polyethylene whose density is larger than the above range, since the lubricating liquid does not sufficiently penetrate into the inner resin layer, for example, the anchor effect is low, and the lubricating liquid coating layer having a certain thickness may be retained. It will be difficult. Further, when the inner resin layer is formed by using an ultra-low density polyethylene having a density lower than the above range, a large amount of the lubricating liquid penetrates, and as a result, a large amount of the lubricating liquid needs to be sprayed. The liquid may fall off, or the thickness of the lubricating liquid coating layer may decrease with time, making it difficult to form a lubricating liquid coating layer having a stable thickness.
When an olefin resin other than polyethylene, such as polypropylene, is used, the wettability to a lubricating liquid, such as vegetable oil, is poorer than that of polyethylene, and a certain thickness so as to cover the entire surface of the inner resin layer. This makes it difficult to form a lubricant coating layer.

As the above LDPE, naturally, an extruded grade is used, and its melt flow rate (MFR) at 190 ° C. is generally in the range of 0.3 to 1.0 g / 10 min.

Further, in the present invention, it is possible to add a known additive (for example, a bleeding additive such as a lubricant) to the above LDPE, but such an additive is added to the lubricating liquid. The wettability may be impaired. Therefore, in the present invention, it is possible to form the inner resin layer using LDPE, in which the amount of such a bleeding additive that reduces the wettability is small (for example, the amount of the additive is 500 ppm or less), in particular, a lubricant-free LDPE. Optimal.
However, commercially available LDPE may contain a lubricant typified by a fatty acid amide for the purpose of ensuring releasability. Even in such a lubricant LDPE, if the compounding amount is 500 ppm or less, particularly less than 300 ppm, it can be used as it is as an LDPE for forming the inner resin layer, and if the compounding amount is large, for example, a lubricant-free It can be blended with LDPE and used for forming the inner resin layer.
By the way, LDPE which is commercially available without a lubricant is expensive and is suitable for applications such as pharmaceuticals, but is not suitable for food applications containing mayonnaise or mayonnaise-like food in terms of cost. Therefore, as described above, the inner resin layer may be formed of LDPE in which a small amount of lubricant is compounded, and the amount of the lubricant in such an inner resin layer is compounded in the outer resin layer described later. Less than the amount of lubricant.

Further, in the present invention, the inner resin layer is formed to have a thickness of 15 to 45% by mass, preferably 20 to 40% by mass, based on the total weight of the bottle excluding the lubricant coating layer.
That is, when the thickness of the inner resin layer is smaller than the above range, during direct blow molding, disadvantages such as breakage are likely to occur at the pinch-off at the end of the melt-extruded cylindrical preform, and Also, the drop strength of the bottle to be dropped is reduced.
Further, when the thickness of the inner resin layer is larger than the above range, the amount of the lubricating liquid that permeates the inner resin layer becomes excessively large, and it is difficult to maintain the thickness of the lubricating liquid coating layer in a predetermined range. turn into.

<Liquid diffusion preventing oxygen barrier layer>
In the present invention, the liquid-diffusion-preventing oxygen barrier layer provided below (on the outer surface side of) the inner resin layer ensures the oxygen barrier property and at the same time prevents the lubricating liquid from penetrating from the lubricating liquid coating layer into the inner resin layer. This layer is provided to prevent further diffusion and penetration.

Such a liquid diffusion preventing oxygen barrier layer is made of an ethylene / vinyl alcohol copolymer (EVOH) known as an oxygen barrier resin, and may further contain low density polyethylene (LDPE).

Such EVOH is a saponified product of an ethylene / vinyl acetate copolymer, and is used to convert an ethylene / vinyl acetate copolymer having an ethylene content of 20 to 60 mol% to a saponification degree of 96 mol% or more, particularly 99 mol% or more. It is obtained by saponification so that In particular, it is known that the smaller the ethylene content, the higher the oxygen barrier property is exhibited. From such a viewpoint, EVOH having an ethylene content of 20 to 60 mol%, particularly 25 to 50 mol%, is suitably used.
Further, such an EVOH has a high density of 1.00 g / cm ³ or more, and a high glass transition point (Tg) of 35 ° C. or more. Therefore, it is possible to effectively prevent the penetration and diffusion of the lubricating liquid. . By using EVOH alone for the liquid diffusion preventing oxygen barrier layer, high oxygen barrier properties can be imparted. In this case, the inner resin layer and the regrind layer adjacent to the EVOH layer have poor adhesion to EVOH, and an adhesive layer is used to prevent delamination.

LDPE is also used for the above-mentioned inner resin layer. By using such LDPE, the liquid diffusion preventing oxygen barrier layer containing EVOH having poor adhesion to the inner resin layer and the inner resin layer are used. The adhesion to the layer is enhanced, and further, the adhesion to the regrind layer described later is also enhanced, and high adhesion strength can be secured. LDPE also has a high moisture resistance (for example, a water absorption of 0.1% or less as measured by ASTM D570), and has a function of suppressing contact between EVOH and moisture and suppressing deterioration of EVOH due to moisture. ing.

When the liquid diffusion preventing oxygen barrier layer contains EVOH and LDPE, it is preferable to use EVOH: LDPE at a mass ratio of 95: 5 to 50:50, particularly 90:10 to 60:40. . That is, by setting the amount of EVOH to be equal to or more than that of LDPE, the oxygen barrier property and the liquid diffusion preventing property of EVOH can be effectively exhibited. For example, when the amount of LDPE is larger than the above range, the oxygen barrier property and the liquid diffusion preventing property are reduced. When the amount of LDPE is in the above range, excellent oxygen barrier properties can be secured by utilizing the oxygen barrier properties of EVOH. On the other hand, if the amount of LDPE used is less than the above range, the adhesiveness between the inner resin layer or the regrind layer is reduced, and between the inner resin layer or the regrind layer and the liquid barrier oxygen barrier layer. Delamination tends to occur easily.

It is more preferable that such a liquid diffusion preventing oxygen barrier layer contains a compatibilizer in addition to EVOH and LDPE.
This compatibilizer is used for compatibilizing EVOH and LDPE, which have poor adhesion to each other, and preventing phase separation between the two.
Examples of the compatibilizer include carboxylic acids such as maleic acid, itaconic acid and fumaric acid or anhydrides thereof, maleic acid-polyethylene copolymer, maleic anhydride-polyethylene copolymer, amide, ester and the like. Graft-modified olefin resin; ethylene- (meth) acrylic acid copolymer; ethylene-vinyl acetate copolymer, saponified ethylene-vinyl acetate copolymer having a saponification degree of 20 to 100%, ethylene content of 85% or more Ethylene-vinyl alcohol copolymer, hydrotalcite compound; ionomer (ion-crosslinked olefin copolymer); and the like. In the present invention, an ionomer is particularly preferably used.

Such an ionomer, that is, an ion-crosslinked olefin copolymer is an ionic salt in which a part or all of the carboxyl groups in a copolymer of ethylene and an α, β-unsaturated carboxylic acid is neutralized with a metal cation. It is.

Examples of the α, β-unsaturated carboxylic acid include unsaturated carboxylic acids having 3 to 8 carbon atoms, such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, maleic anhydride, maleic acid monomethyl ester, and maleic acid. Acid monomethyl ester and the like can be mentioned. In particular, for compatibilization of EVOH and LDPE, an ethylene- (meth) acrylic acid copolymer or an ethylene- (meth) acrylate- (meth) acrylic acid copolymer is preferable.

に お い て In the present invention, the above-mentioned compatibilizer is preferably used in an amount of 1 to 49 parts by mass, particularly 5 to 30 parts by mass per 100 parts by mass of the total amount of EVOH and LDPE. If the ionomer is used in excess, not only the properties required for EVOH and LDPE will be impaired, but also the cost will increase and there is no merit. If the amount of the ionomer is too small, the phase separation between EVOH and LDPE is likely to occur, and the oxygen barrier property, liquid permeation prevention property and adhesiveness may be unstable.

In the present invention, the above-mentioned liquid diffusion preventing oxygen barrier layer usually has a thickness of about 1 μm or more, or about 3 to 80 μm, particularly about 7 to 50 μm in order to sufficiently exhibit the liquid barrier property and the oxygen barrier property. Preferably, it is formed.

混合 In addition, mixing of the above EVOH with LDPE and further with a compatibilizer can be easily performed by, for example, melt-kneading in a kneading section provided in an extruder.

<Regrind layer>
The regrind layer is provided in order to recycle scraps such as burrs and blanks generated during the molding of the bottle, and therefore is derived from the LDPE derived from the inner resin layer and the liquid diffusion preventing oxygen barrier layer. EVOH further contains an oxygen absorbent derived from an oxygen absorbing layer described later. However, since such a scrap has undergone a heat history, various physical properties are deteriorated. For this reason, such scrap is usually used in a mixture with virgin LDPE used for forming the inner resin layer or olefin-based resin used for forming the outer resin layer.
For example, from the viewpoint of reusing resources while maintaining moldability, scrap is blended in an amount of about 10 to 60 parts by weight per 100 parts by weight of olefin resin of virgin.

Such a regrind layer preferably has a thickness of 60% by mass or less of the thickness of the bottle wall (total thickness of each layer excluding the lubricating liquid coating layer) in order to avoid performance degradation due to the regrind layer. In particular, it is preferable to set the thickness to 40 to 50% by mass.

<Oxygen absorption layer>
In the present invention, the oxygen absorbing layer is made of an oxygen absorbing agent, and the oxygen absorbing agent is dispersed in a matrix resin to form the oxygen absorbing layer as needed. By providing such an oxygen absorbing layer, even when the oxygen barrier property of EVOH in the liquid diffusion preventing oxygen barrier layer described above is deteriorated by moisture, the oxygen absorbing property is supplemented by the oxygen absorbing layer. It is possible to minimize a decrease in barrier properties.

The above-mentioned oxygen absorbent is usually composed of an oxidizing organic component, and a transition metal catalyst component is used in combination as necessary. That is, the oxidizing organic component exhibits a function of blocking oxygen by absorbing and oxidizing the oxygen (oxygen absorbing ability), and the transition metal catalyst component is appropriately blended to promote the oxidation of the oxidizing organic component. Things. Such an oxygen absorbent is known, for example, from JP-A-2002-240813.

For example, the oxidizing organic component includes, for example, a polymer containing an ethylenically unsaturated group. This polymer has a carbon-carbon double bond, and this double bond portion is easily oxidized by oxygen, whereby oxygen is absorbed and trapped.

Such an ethylenically unsaturated group-containing polymer is, for example, one derived from a polyene as a monomer, and suitable examples of the polyene used as the monomer are not limited thereto. However, the following can be exemplified.
Conjugated dienes such as butadiene and isoprene;
1,4-hexadiene, 3-methyl-1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 4,5-dimethyl-1,4-hexadiene, 7- Linear non-conjugated dienes such as methyl-1,6-octadiene;
Methyltetrahydroindene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-norbornene, 5-vinylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene And cyclic non-conjugated dienes such as dicyclopentadiene;
Trienes such as 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,2-norbornadiene, chloroprene;

That is, a homopolymer of the above-mentioned polyene, or a random copolymer or a block copolymer obtained by combining two or more kinds of the above-mentioned polyenes or other monomers can be used as the oxidizing polymer.
Examples of other monomers to be copolymerized with the polyene include α-olefins having 2 to 20 carbon atoms, specifically, ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1- Nonadecene, 1-eicosene, 9-methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1-tetradecene and the like can be exemplified. In addition, styrene, vinyltriene, acrylonitrile , Methacrylonitrile, vinyl acetate, methyl methacrylate, ethyl acrylate and the like can also be used.

In the present invention, among the polymers derived from the above-mentioned polyenes, polybutadiene (BR), polyisoprene (IR), natural rubber (NR), nitrile-butadiene rubber (NBR), styrene- Butadiene rubber (SBR), chloroprene rubber, ethylene-propylene-diene rubber (EPDM) and the like are suitable, but of course, are not limited thereto. Further, the iodine value is preferably 100 or more, particularly about 120 to 196.

The above-mentioned oxidizing polymer and its copolymer preferably have a viscosity at 40 ° C. in the range of 1 to 200 Pa · s from the viewpoint of moldability.

Furthermore, a cyclized product of an oxidative polymer obtained by cyclizing a polymer derived from the above-mentioned polyene in the presence of an acid catalyst can also be used as an oxidizable organic component.
As the acid catalyst used in the cyclization reaction, conventionally known acid catalysts can be used. Examples thereof include sulfuric acid, fluoromethanesulfonic acid, difluoromethanesulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid, and an alkyl group having 2 to 18 carbon atoms. Or an organic sulfonic acid compound such as an anhydride or an alkyl ester thereof.
As the cyclized oxidizing polymer described above, a cyclized product of polybutadiene, a cyclized product of polyisoprene, a cyclized product of natural rubber, and the like are preferable, but are not limited thereto.
From the viewpoint of moldability, the weight average molecular weight (Mw) is preferably in the range of 10,000 to 500,000 in terms of polystyrene.

The transition metal catalyst appropriately used is used to promote the oxidation of the oxidizable organic component, as described above, and is generally expressed in terms of transition metal per oxidizable organic component. In a range of 0 to 10000 ppm, and is used in the form of a low-valent inorganic, organic or complex salt of a transition metal.

In such a transition metal catalyst, the transition metal is preferably a Group VIII metal of the periodic table such as iron, cobalt, and nickel. In addition, copper, a Group I metal such as silver, tin, titanium, and zirconium. It may be a Group IV metal, a Group V metal such as vanadium, a Group VI metal such as chromium, or a Group VII metal such as manganese. Among these, cobalt is particularly preferable because it remarkably promotes oxygen absorption (oxidation of the oxidizing organic component).

Examples of the inorganic salts of the transition metal include halides such as chlorides, sulfur oxysalts such as sulfates, nitrogen oxysalts such as nitrates, phosphorus oxysalts such as phosphates, and silicates. .

Examples of the organic salt of the transition metal include a carboxylate, a sulfonate, and a phosphonate, and the carboxylate is preferable for the purpose of the present invention. Specific examples thereof include acetic acid, propionic acid, isopropionic acid, butanoic acid, isobutanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, isoheptanoic acid, octanoic acid, 2-ethylhexanoic acid, nonanoic acid, 3,5,5 -Trimethylhexanoic acid, decanoic acid, neodecanoic acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, arachidic acid, lindelic acid, tuzunic acid, petroselinic acid, oleic acid, linoleic acid, linolenic acid And transition metal salts such as arachidonic acid, formic acid, oxalic acid, sulfamic acid and naphthenic acid.

Transition metal complexes include complexes with β-diketones or β-keto acid esters. Examples of β-diketones and β-keto acid esters include the following.
Acetylacetone,
Ethyl acetoacetate,
1,3-cyclohexadione,
Methylenebis-1,3-cyclohexadione,
2-benzyl-1,3-cyclohexadione,
Acetyltetralone,
Palmitoyltetralone,
Stearoyltetralone,
Benzoyltetralone,
2-acetylcyclohexanone,
2-benzoylcyclohexanone,
2-acetyl-1,3-cyclohexadione,
Benzoyl-p-chlorobenzoylmethane,
Bis (4-methylbenzoyl) methane,
Bis (2-hydroxybenzoyl) methane,
Benzoyl acetone,
Tribenzoylmethane,
Diacetylbenzoylmethane,
Stearoylbenzoylmethane,
Palmitoylbenzoylmethane,
Lauroylbenzoylmethane,
Dibenzoylmethane,
Bis (4-chlorobenzoyl) methane,
Benzoylacetylphenylmethane,
Stearoyl (4-methoxybenzoyl) methane,
Butanoyl acetone,
Distearoylmethane,
Stearoyl acetone,
Bis (cyclohexanoyl) methane,
Dipivaloyl methane and the like.

In the present invention, such an oxygen-absorbing layer is generally set to a thickness of 1 to 10% by mass, especially 3 to 8% by mass of the thickness of the bottle wall (total thickness of each layer excluding the lubricant coating layer). It is suitable.

<Oxygen barrier layer>
In the present invention, an oxygen barrier layer is provided on the outer surface side of the oxygen absorbing layer.
That is, in the present invention, since the oxygen absorption layer and the oxygen barrier layer are provided on the outer surface side of the liquid diffusion preventing oxygen barrier layer, it is possible to more reliably prevent the permeation of oxygen. Even when the oxygen barrier property of the preventive oxygen barrier layer is reduced by moisture in the hydrated substance as the content, the oxidation of the lubricating liquid coating layer due to the permeation of oxygen from the outer surface can be effectively prevented. Further, since the oxygen barrier layer is located at a position distant from the inner surface of the bottle, a decrease in the oxygen barrier property due to the water-containing substance as the content is effectively avoided.

Such an oxygen barrier layer is formed of an oxygen barrier resin known per se.
As such an oxygen barrier resin, EVOH and polyamide used for the liquid diffusion preventing oxygen barrier layer described above are representative.

As described above, EVOH is a saponified product of an ethylene-vinyl acetate copolymer, and is obtained by converting an ethylene-vinyl acetate copolymer having an ethylene content of 20 to 60 mol% to a saponification degree of 96 mol. %, Especially 99 mol% or more. In particular, from the viewpoint of ensuring high oxygen barrier properties, EVOH having an ethylene content of 20 to 60 mol%, particularly 25 to 50 mol%, is preferably used similarly to the liquid diffusion preventing oxygen barrier layer.

Examples of the polyamide include polyamides such as nylon 6, nylon 6.6, nylon 6 / 6,6 copolymer, meta-xylylene diadipamide (MXD6), nylon 6,10, nylon 11, nylon 12, nylon 13, and the like. Can be mentioned. Among these polyamides, those having an amide group number of 5 to 50, particularly 6 to 20 per 100 carbon atoms are preferable in that they have high oxygen barrier properties. For example, these polyamides preferably have a relative viscosity of 1.1 or more, particularly 1.5 or more, measured at 30 ° C. in concentrated sulfuric acid (concentration: 1.0 g / dl).

酸 素 Generally, the oxygen barrier layer is preferably set to a thickness of 1 to 10% by mass, particularly 3 to 8% by mass of the thickness of the bottle (total thickness of each layer excluding the lubricant coating layer).

<Outer resin layer>
In the present invention, the outer resin layer located on the outer surface of the bottle can be formed of various thermoplastic resins, but generally has properties such as flexibility and squeeze properties required for a direct blow bottle. In terms of securing, olefin resins such as low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium or high density polyethylene, polypropylene, poly 1-butene, poly 4-methyl-1-pentene, etc. It is preferable to be formed by Of course, a random or block copolymer of α-olefins such as ethylene, propylene, 1-butene and 4-methyl-1-pentene may be used. Further, polyester resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polyethylene isophthalate can also be used.

Further, it is preferable that a lubricant is blended in the outer resin layer in order to prevent the bottles from being transported and the bottles from sticking to each other.
Typical examples of such a lubricant include fatty acid amides such as stearic acid amide, oleic acid amide, erucic acid amide, and behenic acid amide, liquid paraffin, and organopolysiloxane. Usually, 100 to 1000 ppm in the outer resin layer. It is blended in a ratio of about.
If necessary, known additives such as a pigment, a colorant, and an ultraviolet absorber may be added to the outer resin layer.

厚 み The thickness of such an outer resin layer is usually set appropriately according to the thickness of each layer so that the thickness of the bottle wall (total thickness of each layer excluding the lubricant coating layer) is 10 to 200 μm.

<Other layers>
In the direct blow empty bottle of the present invention, in order to increase the adhesion between the oxygen absorption layer and the adjacent regrind layer or oxygen barrier layer, or to increase the adhesion between the oxygen barrier layer and the outer resin layer. , An adhesive layer can be provided.
The adhesive resin used for forming such an adhesive layer is known per se, and for example, has a carbonyl group (> C） O) in a main chain or a side chain of 1 to 100 meq / 100 g, particularly 10 to 100 meq / 100 g. Resins contained in the amount of resin, specifically, olefin resins graft-modified with carboxylic acids such as maleic acid, itaconic acid, fumaric acid or anhydrides, amides, esters, etc .; ethylene-acrylic acid copolymers; 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 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.
Further, a liquid diffusion preventing oxygen barrier layer may be provided as the above-mentioned adhesive layer. That is, in this layer, LDPE having a function of improving the adhesion between EVOH and the olefin-based resin is compounded, and further, by the addition of an ionomer that functions as a compatibilizer, such adhesion is further enhanced. Because there is. In particular, by providing this liquid diffusion preventing oxygen barrier layer as an adhesive layer, the oxygen barrier properties can be further improved.

<Layer composition of bottle and production of bottle>
In the direct blow empty bottle of the present invention, the lubricating liquid coating layer described above is LB, the inner resin layer is INR, the liquid diffusion preventing oxygen barrier layer is LQBA, the regrind layer is RG, the oxygen absorbing layer is AbO, and the oxygen barrier layer is When BO, the outer resin layer is OR, and the adhesive layer is AD, the present invention is not limited thereto, but may have the following basic layer configuration and other layer configurations.

Basic layer configuration;
(Inner) LB / INR / LQBA / RG / AbO / BO / OR (Outer)
Other layer configurations;
(Inner) LB / INR / LQBA / RG / AbO / AD / BO / AD / OR (Outer)
(Inner) LB / INR / LQBA / RG / AbO / LQBA / BO / LQBA / OR (Outer)
(Inner) LB / INR / AD / LQBA / AD / RG / AbO / AD / BO / AD / OR (Outer)

The direct blow empty bottle of the present invention having such a layer configuration is formed by forming a tube-shaped preform by co-extrusion using the resin or the resin composition forming each layer described above, and forming one end of the preform. Is closed by pinch-off, and in this state, a blow fluid such as air is supplied into the preform to shape the bottle, and finally, a predetermined lubricant is sprayed and sprayed into the bottle to coat the inside of the bottle with the lubricant. It can be manufactured by forming a layer.

ダ イ レ ク ト The thus-obtained direct-blow empty bottle is filled with a predetermined hydrated substance as a content, its mouth is sealed with aluminum foil or the like, and finally a cap is attached to the bottle for sale.

Such a direct-blow empty bottle of the present invention exhibits excellent lubricity with respect to a hydrated substance for a long period of time, and even if this hydrated substance is viscous, it can be quickly discharged and the content in the bottle is reduced. It is also possible to effectively prevent the remaining of the contents, and to use up all the contents.
In addition, while the contents contain moisture, the oxygen barrier property is maintained for a long time, and the contents and the lubricating liquid coating layer (lubricating liquid) can be effectively prevented from being oxidized and deteriorated. Can be maintained for a long time.

優 れ The excellent effects of the present invention will be described with reference to the following experimental examples. The containers obtained in Examples and Comparative Examples were measured and evaluated by the following methods.

[Evaluation of residual content]
After spraying a predetermined amount of a lubricating liquid onto a multilayer bottle having a capacity of 300 g prepared by a method described later, 300 g of the content was filled. Then, a cap was attached to the mouth of the bottle and stored in a constant temperature room at 23 ° C. for 2 weeks. After storage, squeezing was repeated until the contents were no longer discharged, and the remaining amount was determined. The smaller the residual amount, the more excellent the slip property on the inner surface of the container, and the evaluation was performed based on the following criteria.
：: The residual amount of the content is less than 15 g. Δ: The residual amount of the content is 15 g or more and less than 30 g.

[Measurement of lubricating liquid penetration amount]
In a multilayer bottle having a capacity of 300 g produced by a method described later, the inner resin layer was separated, and the mass was measured. The separated sample was immersed in a lubricating liquid and stored in a 45 ° C. constant temperature room for one week. After storage, the removed sample was washed with a neutral detergent and water to remove water, and then weighed. The table below shows the amount of lubricant permeated per unit area.

The materials used to make the bottle are as follows.
Lubricating liquid: Cooking oil (rapeseed oil manufactured by Nisshin Oillio Co., Ltd.)
Inner surface resin layer: Low-density polyethylene without lubricant (density 0.922 g / cm ³ )
Liquid diffusion preventing oxygen barrier layer: Ethylene / vinyl alcohol copolymer (density 1.20 g / cm ³ ), low density polyethylene (density 0.922 g / cm ³ ) and ionomer are melted in a weight ratio of 7: 3: 1. After kneading, a pelletized product was used.
Regrind layer: A dry blend of 50 parts by weight of scrap at the time of bottle production and 50 parts by weight of low-density polyethylene used for the outer resin layer was used.
Oxygen absorbing layer: 100 parts by weight of low-density polyethylene, 5 parts by weight of a styrene resin, and 350 ppm of cobalt neodecanoate as a transition metal catalyst in terms of cobalt were blended, melt-kneaded, and pelletized.
Oxygen barrier layer: same as liquid diffusion preventing oxygen barrier layer
Outer surface resin layer: low-density polyethylene (density 0.922 g / cm ³ , lubricant addition amount 300 ppm)

The following were used as contents to be filled in the bottle.
Kewpie half viscosity manufactured by Kewpie Co., Ltd. (using a BH type viscometer, rotation speed: 2 rpm, rotor: No.
6, the viscosity was converted from the reading after two rotations under the measurement conditions of room temperature of 25 ° C.): 125 Pa · s

[Example 1]
Using the five extruders, a multilayer parison of the following five types and six layers was molded, and a multilayer bottle having an internal capacity of 300 g and a total mass of 15 g was obtained by direct blow molding using the multilayer parison.
(Inside) Inner surface resin layer (15) / Liquid diffusion preventing oxygen barrier layer (5) / Regrind layer (57.5) / Oxygen absorption layer (2.5) / Oxygen barrier layer (5) / Outer surface resin layer ( 15) (outside) (unit: mass%)
The above multi-layer bottle was coated with a lubricating liquid and further filled with contents, and various tests were performed. The results are shown in Table 1 together with the inner resin layer ratio and the amount of lubricating liquid applied.

[Examples 2 to 7 and Comparative Examples 1 and 2]
A multilayer bottle was molded and subjected to various tests in the same manner as in Example 1, except that the inner surface resin layer ratio and the amount of the lubricating liquid applied were changed as shown in Table 1, and the results are also shown in Table 1. .
The ratio of the inner resin layer was changed by changing the thickness (% by mass) of the regrind layer so as not to change the total mass.

Claims (10)

1. In direct blow empty bottles filled with hydrated substances and used,
   A lubricating liquid coating layer formed of a lubricating liquid for improving lubricity with respect to the water-containing substance, an inner resin layer serving as a base of the coating layer, and a liquid diffusion preventing oxygen for preventing diffusion of the lubricating liquid The barrier layer, the oxygen absorption layer, the oxygen barrier layer and the outer resin layer are formed in this order from the inner surface to the outer surface,
   The water-containing substance is an oil-in-water emulsified food having a viscosity of 30 Pa · s or more,
   The inner resin layer is formed of low-density polyethylene, and the inner resin layer is formed to have a thickness of 15 to 45% by mass relative to the total mass of the bottle excluding the lubricant coating layer. Direct blow empty bottle.
2. 2. The direct blow empty bottle according to claim 1, wherein the liquid diffusion preventing oxygen barrier layer comprises an ethylene / vinyl alcohol copolymer.
3. The direct blow empty bottle according to claim 1, wherein the liquid diffusion preventing oxygen barrier layer contains an ethylene / vinyl alcohol copolymer, low-density polyethylene, and a compatibilizer.
4. ^2. The direct blow empty bottle according to claim 1, wherein the lubricant coating layer is formed with a thickness of 1.0 to 35.0 g / m ² .
5. ダ イ レ ク ト The direct blow empty bottle according to claim 1, wherein an oily liquid is used as the lubricating liquid.
6. The direct blow empty bottle according to claim 5, wherein an edible oil is used as the oily liquid.
7. The direct-blow empty bottle according to claim 6, wherein vegetable oil contained in the oil-in-water emulsified food is selected as the edible oil.
8. The direct-blow empty bottle according to claim 1, wherein the inner resin layer is free of a lubricant or has a smaller amount of a lubricant added than the outer resin layer.
9. The direct blow empty bottle according to claim 1, wherein a part of the lubricating liquid permeates into the inner resin layer.
10. A bottled oil-in-water emulsified food filled in the direct blow empty bottle according to claim 1.