JP2017159927A - Laminate tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate tube comprising oxygen barrier property, solvent barrier property and strong connectivity.SOLUTION: There is provided a laminate tube 10 in which, a shoulder part 13 and a mouth 12 are molded by a compression molding method on one opening end of a trunk 11 having barrier property and formed into a cylindrical shape, in which a resin forming the shoulder part and the mouth comprises a resin composition formed of 60-90 mass% of polyolefin, 2-35 mass% of a meta-xylilene group containing polyamide, and 5-30 mass% of modified polyolefin, and in the polyolefin 21, meta-xylilene group containing polyamide 22B is dispersed in an island-state, and when a vertical dimension and a lateral dimension of the meta-xylilene group containing polyamide in an initial state are 1, respectively, a vertical dimension of the meta-xylilene group containing polyamide and a lateral dimension of the meta-xylilene group containing polyamide after compression molding, are 3.0-4.5, and 0.5-0.6, respectively.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laminate tube, and more particularly to a technique suitable for use in a laminate tube excellent in various barrier properties.

  As a laminated tube for protecting food, pharmaceuticals, etc., an oxygen barrier material is used in order to prevent the contents from being oxidized and deteriorated by oxygen in the outside air. As a conventional oxygen barrier material, a general plastic film coated with a substance having oxygen barrier performance is known. Furthermore, an oxygen barrier material in which aluminum, silica, alumina, or the like is vapor-deposited on a film in order to exhibit a high degree of oxygen barrier properties is also known.

On the other hand, aesthetics, ease of handling, manufacturing cost, etc. are also very important for laminated tubes. As the laminate tube, polyolefins such as polyethylene (PE) and polypropylene (PP) are often used as the material.
However, since polyolefins such as polyethylene (PE) and polypropylene (PP) have poor oxygen barrier properties, there is a problem that they cannot be used alone to prevent oxidative degradation.

  On the other hand, as plastics having oxygen barrier properties, nylon (Ny), polyvinyl alcohol (PVA), ethylene vinyl alcohol copolymer resin (EVOH), polyvinylidene chloride (PVDC), and the like are known. . Among nylons, nylon 6 is the most frequently used for oxygen barrier applications. In particular, so-called MX nylon composed of meta-xylenediamine / adipic acid is known to have a higher oxygen barrier property among Ny-based films.

  By the way, Patent Document 1 discloses a hollow container made of a resin composition obtained by melt-mixing a polyolefin, a metaxylylene group-containing polyamide, and a modified polyolefin, and a method for producing the same. Specifically, Patent Document 1 discloses that the above-mentioned resin composition is molded by a direct blow method so that the metaxylylene group-containing polyamide can be dispersed in a flaky shape in the resin composition. However, it is disclosed that a hollow container having excellent barrier properties can be obtained.

Furthermore, regarding the body portion of the laminate tube, it was possible to impart barrier properties by using a metal foil or a film having excellent barrier properties, but it was difficult to impart barrier properties to the shoulder portions. . For this reason, as shown in Patent Document 2, a metal foil or a film excellent in barrier properties is inserted in order to give the shoulder portion a barrier property, molded separately, and the side body film is joined together to form a barrier property. Those that give are known.
Also, a resin as disclosed in Patent Document 3 is known as a tube resin.

JP 2011-162684 A Japanese Patent No. 2886966 International Publication No. 2008/047902

However, even when the resin composition disclosed in Patent Document 1 is used as a raw material, if the required oxygen barrier property is severe, it may be difficult to satisfy the condition with a single layer. It was.
In particular, a laminate tube for storing contents containing solvents such as agricultural chemicals and printing inks is required to have a solvent barrier property. However, even when the resin composition disclosed in Patent Document 1 is used as a raw material, a molding method other than the direct blow method has a problem that it is a single layer and the required barrier property cannot be obtained. It was. That is, in order to obtain a single-layer laminate tube having excellent barrier properties, it is necessary to form the above-mentioned resin composition by the direct blow method, but there is a problem that it cannot be applied to the production of a laminate tube.

Furthermore, in the technique of Patent Document 2, since the shoulder portion and the trunk portion of the laminate tube are joined again, there is a problem that the joint strength is deteriorated depending on the contents and the barrier performance is lowered. Furthermore, since shoulder molding is performed in a separate process, there is a problem that the number of processes increases and the manufacturing cost increases.
Further, the technique of Patent Document 3 has a problem that the barrier property at the shoulder is not sufficient.

The present invention has been made in view of the above circumstances, and intends to achieve the following object.
1. To provide a laminated tube having excellent oxygen barrier property and solvent barrier property.
2. Provided is a laminated tube having an oxygen barrier property and a solvent barrier property in a shoulder portion formed as a single layer.
3. In the shoulder, the joint strength is prevented from being deteriorated by the contents.
4). Reduce the number of manufacturing processes and reduce manufacturing costs.

The laminated tube of the present invention is a laminated tube in which a shoulder portion and a mouth portion are formed at one opening end of a barrel portion having a barrier property formed in a cylindrical shape.
The resin forming at least the shoulder and the mouth has a resin composition composed of 60 to 90% by mass of polyolefin, 2 to 35% by mass of polyamide containing metaxylylene group, and 5 to 30% by mass of modified polyolefin. ,
In the polyolefin, the metaxylylene group-containing polyamide is dispersed in an island shape, and when the vertical dimension and the horizontal dimension of the initial metaxylylene group-containing polyamide are set to 1, respectively, after the shoulder portion and the mouth portion are molded The said subject was solved by the vertical dimension of the said metaxylylene group containing polyamide being 3.0-4.5, and a horizontal dimension being 0.5-0.6.
In the laminated tube of the present invention, when the thickness dimension of the metaxylylene group-containing polyamide in the initial state is 1, the thickness dimension of the metaxylylene group-containing polyamide after molding the shoulder portion and the mouth portion is 0.5. It can be ~ 0.6.
In the laminated tube of the present invention, the polyolefin may be high density polyethylene.
In the laminated tube of the present invention, the surface of the body portion can be made of the polyolefin.
In the laminated tube of the present invention, the body portion may have a layer made of aluminum as a barrier layer.
In the laminate tube of the present invention, the body portion may have a PET layer.
The laminate tube production method of the present invention is a laminate tube production method in which a shoulder portion and a mouth portion are formed by a compression molding method at one opening end of a barrel portion having a barrier property formed in a cylindrical shape.
Preparing a resin composition obtained by melting and mixing 60 to 90% by mass of a polyolefin, 2 to 35% by mass of a metaxylylene group-containing polyamide, and 5 to 30% by mass of a modified polyolefin;
The shoulder portion and the mouth portion can be formed by compression molding the resin composition.

The laminated tube of the present invention is a laminated tube in which a shoulder portion and a mouth portion are formed at one opening end of a barrel portion having a barrier property formed in a cylindrical shape.
The resin forming at least the shoulder and the mouth has a resin composition composed of 60 to 90% by mass of polyolefin, 2 to 35% by mass of polyamide containing metaxylylene group, and 5 to 30% by mass of modified polyolefin. ,
In the polyolefin, the metaxylylene group-containing polyamide is dispersed in an island shape, and when the vertical dimension and the horizontal dimension of the initial metaxylylene group-containing polyamide are set to 1, respectively, after the shoulder portion and the mouth portion are molded When the longitudinal dimension of the metaxylylene group-containing polyamide is 3.0 to 4.5 and the lateral dimension is 0.5 to 0.6, the mouth part and shoulder part of the single layer and the trunk part are continuously provided. At the same time, it can have oxygen barrier properties and solvent barrier properties in the vicinity of the shoulder portion formed as a single layer. This makes it possible to prevent the joint strength from being deteriorated by the contents at the shoulder, reducing the number of manufacturing steps, reducing the manufacturing cost, and having a superior oxygen barrier property and solvent barrier property. A tube can be provided.

  In the laminated tube of the present invention, when the thickness dimension of the metaxylylene group-containing polyamide in the initial state is 1, the thickness dimension of the metaxylylene group-containing polyamide after molding the shoulder portion and the mouth portion is 0.5. By being -0.6, the outstanding solvent barrier property by the said metaxylylene group containing polyamide can be exhibited.

  In the laminate tube of the present invention, since the polyolefin is high-density polyethylene, it is possible to exhibit properties such as solvent barrier properties while maintaining the moldability as a laminate tube.

  In the laminated tube of the present invention, the surface of the body portion is made of the polyolefin, so that the solvent barrier property and the strength at the joint are maintained, and the mouth portion and the shoulder portion of the single layer and the body portion are continuously formed. It can be formed integrally.

  The laminate tube of the present invention can exhibit a sufficient barrier property in the body portion when the body portion has a layer made of aluminum as a barrier layer.

  The laminate tube of the present invention can exhibit a sufficient strength in the body part because the body part has a PET layer.

The laminate tube production method of the present invention is a laminate tube production method in which a shoulder portion and a mouth portion are formed by a compression molding method at one opening end of a barrel portion having a barrier property formed in a cylindrical shape.
Preparing a resin composition obtained by melting and mixing 60 to 90% by mass of a polyolefin, 2 to 35% by mass of a metaxylylene group-containing polyamide, and 5 to 30% by mass of a modified polyolefin;
By forming the shoulder portion and the mouth portion by compression molding the resin composition, characteristics such as solvent barrier properties can be exhibited while maintaining ease of molding as a laminate tube.

  According to the present invention, it is possible to continuously form the mouth portion and shoulder portion of the single layer and the trunk portion, and at the same time have oxygen barrier property and solvent barrier property in the vicinity of the shoulder portion formed as a single layer. This makes it possible to prevent the joint strength from being deteriorated by the contents at the shoulder, reduce the number of manufacturing steps, reduce the manufacturing cost, and have excellent oxygen barrier properties and solvent barrier properties. The effect that it becomes possible to provide a laminate tube can be produced.

It is a perspective view which shows 1st Embodiment of the laminate tube which concerns on this invention. It is a schematic cross section which shows the manufacturing process in 1st Embodiment of the laminated tube which concerns on this invention. It is a schematic cross section which shows the manufacturing process in 1st Embodiment of the laminated tube which concerns on this invention. It is a model expanded sectional view which shows the resin plastic material in FIG. It is arrow sectional drawing along the AA 'line in FIG. It is a model expanded sectional view which shows the laminate tube in FIG. It is arrow sectional drawing along BB 'in FIG.

Hereinafter, a first embodiment of a laminated tube according to the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing a laminated tube according to the present embodiment. In the figure, reference numeral 10 denotes a laminated tube.

  As shown in FIG. 1, the laminated tube 10 according to the present embodiment has a shoulder 12 and a shoulder 12 formed on one open end (upper open end in the figure) of a cylindrical body 11 having heat resistance by a compression molding method. The mouth portion 13 is attached by heat welding at the same time as molding, and the outer peripheral surface of the mouth portion 13 is provided with a screw thread 14 for mounting a cap 15 as a separate body. The shoulder 12 and the mouth 13 are formed using a single layer resin as will be described later.

  In addition, it is also possible to seal the upper end of the mouth portion 13 with a thin body having a barrier property such as aluminum foil without providing the cap 15. As an example of this seal, a sealing material having a structure in which a biaxially stretched polyethylene terephthalate film, an aluminum foil, and a polypropylene resin sealant layer are sequentially laminated from the outside can be thermally bonded to improve the sealing performance.

Further, since the bottom portion 16 of the laminate tube 10 is used as a filling port for the contents, it is an unsealed opening before filling the contents, and is sealed by thermal bonding after filling the contents.
When the cap 15 is provided, it can be produced by injection molding using the same resin as the shoulder portion 12 and the mouth portion 13. A thread groove 17 can be provided to be screwed into the mountain 14.

The trunk portion 11 is formed into a cylindrical shape made of a laminate (film) having a barrier property, and has, for example, an aluminum layer. It is supposed to be. The laminated body having a barrier property of the body portion 11 is a layer made of aluminum as a barrier layer, a PET layer, an inorganic vapor deposition barrier layer (alumina, silicon oxide, etc.) or a metal thin film on a base film (PET, nylon, etc.) It can have a deposited film on which the layers are deposited.
The inner surface of the body portion 11 is preferably made of a polyethylene resin in consideration of adhesiveness with the shoulder portion 12.

  The shoulder part 12 and the mouth part 13 have a resin composition composed of 60 to 90% by mass of polyolefin, 2 to 35% by mass of a metaxylylene group-containing polyamide, and 5 to 30% by mass of a modified polyolefin. When the above-mentioned metaxylylene group-containing polyamide is dispersed in an island shape, and the initial dimension and the horizontal dimension of the metaxylylene group-containing polyamide are 1, respectively, the metaxylylene group-containing polyamide after compression molding as described later Are formed of a single layer resin having a vertical dimension of 3.0 to 4.5 and a horizontal dimension of 0.5 to 0.6.

  In the shoulder portion 12 and the mouth portion 13, when the thickness dimension of the initial metaxylylene group-containing polyamide is 1, the thickness dimension of the metaxylylene group-containing polyamide after compression molding is 0.5, as will be described later. Can be -0.6, and the polyolefin is a high density polyethylene.

  First, the manufacturing method of the laminate tube 10 which is one Embodiment which concerns on this invention is demonstrated.

The manufacturing method of the laminated tube 10 of this embodiment is as follows. As the trunk portion 11, the front and back surfaces are made of the same polyolefin as the shoulder portion 13, and have an aluminum layer for exhibiting a barrier property, and PET for exhibiting sufficient strength. A film having a layer formed into a cylindrical shape is prepared, and the shoulder portion 12 and the mouth portion 13 are integrally formed thereon.
As the trunk | drum 11, it can be set as the laminated film which the surface consists of polyethylene.

<Manufacturing method of shoulder and mouth>
The manufacturing method of the laminate tube 10 of this embodiment uses the resin composition obtained by melt-mixing polyolefin, metaxylylene group containing polyamide, and modified polyolefin as a raw material of the shoulder part 12 and the mouth part 13 in the laminate tube 10. Use.

"Polyolefin"
The polyolefin is not particularly limited, and materials having a wide range of melt viscosities can be used. Specifically, for example, selected from linear low density polyethylene resin, low density polyethylene resin, medium density polyethylene resin, high density polyethylene resin, ultra high molecular weight high density polyethylene resin, polypropylene resin, ethylene, propylene, butene, etc. A resin composed of a copolymer of two or more types of olefins, and a mixture thereof can be used.

"Metaxylene group-containing polyamide"
The metaxylylene group-containing polyamide has a diamine unit and a dicarboxylic acid unit, and can be imparted with an effect of improving the barrier performance of the molded laminate tube by being included in the resin composition.

  The diamine unit constituting the metaxylylene group-containing polyamide is not particularly limited. Specifically, for example, metaxylenediamine, paraxylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (Aminomethyl) cyclohexane, tetramethylenediamine, hexamethylenediamine, nonanemethylenediamine, 2-methyl-1,5-pentanediamine and the like can be used.

  In the production method of the present embodiment, as the metaxylene group-containing polyimide, for example, those containing 70 mol% or more of metaxylylenediamine units are preferable, those containing 80 mol% or more are more preferable, and those containing 90 mol% or more are further included. preferable. By using a metaxylene group-containing polyimide containing a metaxylenediamine unit in an amount of 70 mol% or more for the resin composition, the gas barrier property at the molded shoulder portion 13 and the mouth portion 12 and the joint portion between the shoulder portion 13 and the trunk portion 11 can be efficiently obtained. Can be increased.

  The dicarboxylic acid unit constituting the metaxylene group-containing polyimide is not particularly limited. Specifically, for example, α, ω-aliphatic dicarboxylic acid, 1,3-cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid are used. An aromatic dicarboxylic acid such as alicyclic dicarboxylic acid such as terephthalic acid, isophthalic acid, orthophthalic acid, xylylene dicarboxylic acid, and naphthalenedicarboxylic acid can be used. Among these, isophthalic acid, 2,6-naphthalenedicarboxylic acid, and the like are preferable because a polyamide having excellent barrier properties can be easily obtained without inhibiting the polycondensation reaction in producing a metaxylylene group-containing polyamide. .

  In the production method of this embodiment, as the metaxylene group-containing polyimide, for example, those containing 50 mol% or more of dicarboxylic acid units such as α, ω-aliphatic dicarboxylic acid are preferable, and those containing 60 mol% or more are more preferable. Those containing 70 mol% or more are more preferable. By making a dicarboxylic acid unit 70 mol% or more, it can suppress that the crystallinity of a metaxylene group containing polyimide falls excessively.

  Specific examples of the α, ω-aliphatic dicarboxylic acid include suberic acid, adipic acid, azelaic acid, sebacic acid, and dodecanoic acid. Among these, it is preferable to use adipic acid or sebacic acid from the viewpoint of excellent performance for maintaining good gas barrier properties and crystallinity.

  The metaxylene group-containing polyimide is a copolymer unit other than the diamine unit and the dicarboxylic acid unit as long as it does not impair the effects of the present invention. It may contain aliphatic aminocarboxylic acids, aromatic aminocarboxylic acids such as para-aminomethylbenzoic acid, and the like.

  The metaxylylene group-containing polyamide can be produced using a melt polycondensation (melt polymerization) method. Specifically, for example, a method may be mentioned in which a nylon salt composed of diamine and dicarboxylic acid is heated in the presence of water and under pressure, and polymerized in a molten state while removing added water and condensed water.

  Moreover, it can manufacture also by the method of adding a diamine directly to dicarboxylic acid of a molten state, and performing polycondensation. In this case, it is preferable to keep the reaction system in a uniform liquid state. Specifically, it is preferable to carry out the polycondensation reaction while raising the temperature of the reaction system so that the reaction temperature does not fall below the melting point of the resulting oligoamide and polyamide during the continuous addition of diamine to the dicarboxylic acid.

  A phosphorus atom-containing compound may be contained in the polycondensation system of the metaxylene group-containing polyimide. By including a phosphorus atom-containing compound in the polycondensation system of the metaxylene group-containing polyimide, an effect of promoting an amidation reaction and an effect of preventing coloring during polycondensation can be obtained.

  The phosphorus atom-containing compound is not particularly limited. Specifically, for example, dimethylphosphinic acid, phenylmethylphosphinic acid, hypophosphorous acid, sodium hypophosphite, potassium hypophosphite, hypophosphorous acid. Lithium, ethyl hypophosphite, phenylphosphonic acid, sodium phenylphosphonite, potassium phenylphosphonite, lithium phenylphosphonite, ethyl phenylphosphonite, phenylphosphonic acid, ethylphosphonic acid, sodium phenylphosphonate, Potassium phenylphosphonate, lithium phenylphosphonate, diethyl phenylphosphonate, sodium ethylphosphonate, potassium ethylphosphonate, phosphorous acid, sodium hydrogen phosphite, sodium phosphite, triethyl phosphite, triphenyl phosphite , Pyrophosphorus Or the like can be used. Among these, because hypophosphite metal salts such as sodium hypophosphite, potassium hypophosphite, and lithium hypophosphite are highly effective in promoting the amidation reaction and are excellent in anti-coloring effects. Sodium hypophosphite is preferred and particularly preferred.

  The addition amount of the phosphorus atom-containing compound added to the metaxylene group-containing polyimide is preferably 1 to 500 ppm, more preferably 5 to 450 ppm in terms of phosphorus atom concentration in the metaxylylene group-containing polyamide. More preferably, it is 400 ppm. By setting the addition amount of the phosphorus atom compound within the above range, coloring of the xylylene group-containing polyamide during polycondensation can be prevented.

  The polycondensation system of the metaxylene group-containing polyimide preferably contains an alkali metal compound or an alkaline earth metal compound together with the phosphorus atom-containing compound. By allowing an alkali metal compound or an alkaline earth metal compound to coexist with the phosphorus atom-containing compound, the amidation reaction rate can be adjusted.

The alkali metal compound and the alkaline earth metal compound are not particularly limited. Specifically, for example, lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, magnesium hydroxide, water Alkali metal and alkaline earth metal hydroxides such as calcium oxide and barium hydroxide, and alkali metals and alkalis such as lithium acetate, sodium acetate, potassium acetate, rubidium acetate, cesium acetate, magnesium acetate, calcium acetate, and barium acetate Examples include earth metal acetates.

  When an alkali metal compound or an alkaline earth metal compound is added to the metaxylene group-containing polyimide, a value obtained by dividing the number of moles of the alkali metal compound or alkaline earth metal compound by the number of moles of the phosphorus atom-containing compound is 0.5 to The range is preferably 2.0, more preferably in the range of 0.6 to 1.8, and still more preferably in the range of 0.7 to 1.5. By setting the addition amount of the alkali metal compound or alkaline earth metal compound in the above range, gel formation can be suppressed while obtaining the amidation reaction promoting effect by the phosphorus atom-containing compound.

  The metaxylylene group-containing polyamide obtained by melt polycondensation is once taken out, pelletized, and dried before use. Further, in order to further increase the degree of polymerization, solid phase polymerization may be performed. The heating apparatus used for drying or solid phase polymerization is not particularly limited, and a known method and apparatus can be used. Specifically, as such a heating device, for example, a continuous heating drying device, a tumble dryer, a conical dryer, a rotary dryer called a rotary dryer or the like, and an inside called a Nauta mixer are used. Examples thereof include a conical heating device provided with a rotary blade. Among these, the batch-type heating apparatus is useful particularly when solid-phase polymerization of polyamide is performed because the inside of the system can be sealed and the polycondensation can easily proceed in a state where oxygen that causes coloring is removed.

  In addition, metaxylylene group-containing polyamides are antioxidants, matting agents, heat stabilizers, weathering stabilizers, ultraviolet absorbers, nucleating agents, plasticizers, flame retardants, electrification, as long as the effects of this embodiment are not impaired. Additives such as inhibitors, anti-coloring agents, lubricants, anti-gelling agents, clays such as layered silicates, nanofillers, and the like may be included. Further, for the purpose of modifying the xylylene group-containing polyamide, various polyamides such as amorphous nylon using nylon 6 and nylon 66 and aromatic dicarboxylic acid as a monomer, modified resins thereof, polyolefins and modified resins thereof, if necessary, An elastomer having styrene in the skeleton may be added.

"Modified polyolefin"
The modified polyolefin used in the production method of the present embodiment is obtained by graft-modifying the above-described polyolefin with an unsaturated carboxylic acid or an anhydride thereof. This modified polyolefin is generally widely used as an adhesive resin.

  Specific examples of the unsaturated carboxylic acid or anhydride thereof include acrylic acid, methacrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, and chloromaleic acid. , Butenyl succinic acid and the like, and their acid anhydrides. Of these, maleic acid and maleic anhydride are preferably used.

  The method for obtaining the modified polyolefin by graft copolymerization of the unsaturated carboxylic acid or anhydride thereof with the polyolefin is not particularly limited, and various conventionally known methods can be used. Specifically, for example, a method of melting a polyolefin using an extruder or the like, adding a graft monomer and copolymerizing, a method of dissolving a polyolefin in a solvent and adding a graft monomer, and copolymerizing the polyolefin, Examples thereof include a method of copolymerization by adding a graft monomer after making an aqueous suspension.

"Resin composition"
In the production method of the present embodiment, the polyolefin content in the resin composition is 60 to 100 mass% (that is, 100 mass% of the resin composition) with respect to a total of 100 mass% of the polyolefin, the metaxylene group-containing polyamide, and the modified polyolefin. It is preferable to set it as 90 mass%. By setting the content of the polyolefin in the resin composition within the above range, the strength reduction of the container blended with the metaxylylene group-containing polyamide can be minimized.

  The content of the metaxylylene group-containing polyamide in the resin composition is 2 to 35% by mass with respect to 100% by mass in total of the polyolefin, the metaxylylene group-containing polyamide, and the modified polyolefin (that is, 100% by mass of the resin composition). It is preferable that By setting the metaxylylene group-containing polyamide in the resin composition within the above range, the barrier performance of the shoulder portion 13 and the mouth portion 12 can be efficiently increased, and the strength reduction of the shoulder portion 13 and the mouth portion 12 can be practically used. In addition, the adhesiveness between the shoulder portion 13 and the trunk portion 11 and the barrier performance can be reliably maintained.

  Further, the content of the modified polyolefin in the resin composition is 5 to 30% by mass with respect to 100% by mass in total of the polyolefin, the hydroxylene group-containing polyamide, and the modified polyolefin (that is, 100% by mass of the resin composition). It is preferable. By setting the modified polyolefin in the resin composition within the above range, the adhesion between the non-adhesive polyolefin and the metaxylylene group-containing polyamide is improved, the strength of the shoulder 13 and the mouth 12 is increased, and the shoulder 13 It is possible to reliably maintain the adhesiveness between the body 11 and the barrier 11 and the barrier performance.

  Further, the content of the modified polyolefin relative to the metaxylylene group-containing polyamide in the resin composition is preferably 0.8 to 5.0 times by mass ratio, more preferably 1.0 to 4.5 times. More preferably, the ratio is 1.0 to 4.0 times. By setting the content of the modified polyolefin within the above range, the strength of the shoulder portion 13 and the mouth portion 12 can be increased, and the adhesion between the shoulder portion 13 and the trunk portion 11 and the barrier performance can be reliably maintained.

The laminated tube 10 obtained by the manufacturing method of the present embodiment includes a thermoplastic elastomer for modification purposes in addition to the above-mentioned three components of the polyolefin, metaxylylene group-containing polyamide, and modified polyolefin at the shoulder portion 13 and the mouth portion 12. In addition, various copolymerized polyolefins such as EEA (ethylene-ethyl acrylate) and EMA (ethylene-methyl acrylate), ionomers, and the like may be included.
Furthermore, as will be described later, burrs generated in the manufacturing process of the shoulder portion 13 and the mouth portion 12 and a material obtained by pulverizing defective products that have not become products may be mixed.

  The manufacturing method of this embodiment manufactures the laminated tube 10 which is a molded article by the compression molding method using the resin composition described above as a raw material. FIG. 2 FIG. 3 shows a schematic cross-sectional view in the manufacturing process by the compression molding method.

"Compression molding method"
As shown in FIGS. 2 to 3, the compression molding method is roughly configured including a step of forming a shoulder portion and a mouth portion by compression molding. Moreover, as a device applied to the compression molding method, for example, a known device can be used.

(Compression molding process)
Specifically, in the manufacturing method of this embodiment, first, as shown in FIG. 2, a cylindrical laminate film that becomes the body portion 11 is cut into a predetermined length, and an opening at one end projects as a connection region. Thus, it sets as the state wound around the cylindrical metal mold | die 2B formed in convex shape.
In this state, for example, a resin composition (melting temperature 238 ° C.) 10A obtained by melting and kneading the above-described polyolefin, metaxylylene group-containing polyamide, and modified polyolefin with an extruder (not shown) having a set temperature of 240 ° C. is connected to an adapter ( Via a not-shown), the mold 2B and the periphery of the mold 2B are covered, and the shoulder portion 13 is inserted into a position that becomes a molding space formed by the female molds 2A and 2C.

  Here, FIG. 4 shows a schematic enlarged cross-sectional view of the resin composition 10A put into the molds 2A to 2C. As shown in FIG. 4, in the resin composition 10A melt-kneaded by an extruder, the dispersed state of the metaxylylene group-containing polyamide 12A in the polyolefin 11 is a large sea-island shape. In other words, in the resin composition 10 </ b> A, the metaxylylene group-containing polyamide 12 </ b> A is coarsely dispersed in the polyolefin 11.

  FIG. 5 shows a cross section taken along line A-A ′ shown in FIG. 4. As shown in FIGS. 4 and 5, the metaxylylene group-containing polyamide 12A in the resin composition 10A has a shape close to a circle regardless of any cross section, and a shape close to a sphere as a whole.

  Next, as shown in FIG. 3, the molds 2A and 2B are closed at a low pressure (for example, about 784 kPa), the resin composition is heated (mold temperature: about 80 ° C.), and degassing is performed. The mold 2A, 2B is closed at a high pressure (clamping pressure: about 1960 kPa), and the resin is fluidized and solidified by the heat of the mold, so that the laminated tube 10B in which the shoulder portion 13 and the mouth portion 12 and the body portion 11 are integrated. Form.

  Here, FIG. 6 shows a schematic enlarged cross-sectional view of the formed laminate tube 10B. As shown in FIG. 6, in the laminate tube 10B, the dispersion state of the metaxylylene group-containing polyamide 12B in the polyolefin 11 is a small sea-island shape. In other words, in the laminate tube 10 </ b> B, the metaxylylene group-containing polyamide 12 </ b> B is densely dispersed in the polyolefin 11.

  FIG. 7 shows a cross section along the line B-B ′ shown in FIG. 6. As shown in FIG. 6 and FIG. 7, the metaxylylene group-containing polyamide 12B in the laminate tube 10B has an elliptical shape having a major axis in a direction parallel to the extrusion direction regardless of any cross section. It is deformed into a shape that is crushed to a state close to a (spheroid).

  Thereafter, the mouth portion 12 is closed by a cap 15 formed in the same manner as the laminated tube 10B having a finish such as deburring, and the bottom portion 16 can be sealed by filling the contents therein.

  By the way, in the manufacturing method of the present embodiment, in order to obtain a laminated tube having excellent barrier properties, it is important to disperse the metaxylylene group-containing polyamide in a thin single-sided shape in the resin composition. Further, in order to always form a laminated tube with stable performance, it is necessary that the dispersion state of the metaxylylene group-containing polyamide in the resin composition does not vary even if the molding conditions slightly vary.

  In the production method of the present embodiment, in the compression molding described above, it is important to deform the metaxylylene group-containing polyamide in the resin composition into a thin piece surface. Therefore, it is necessary to set the mold temperature in the compression molding process in consideration of the temperature at which the softening of the metaxylylene group-containing polyamide starts, and to heat and extrude the resin composition 10A before the compression molding process.

  As described above, the laminate tube 10 according to this embodiment is formed by molding a resin composition by a compression molding method. Therefore, the metaxylylene group-containing polyamide is dispersed in a thin single-sided form in the resin composition to form an oxygen barrier layer. Thereby, it becomes the laminated tube 10 which has the single layer shoulder part 13 and mouth part 12 which have the outstanding oxygen barrier property and solvent barrier property.

Specifically, as the oxygen barrier property of the laminated tube 10 according to the present embodiment, for example, when the average thickness of the shoulder 13 and the mouth 12 is 1.0 mm, the oxygen of the container measured by the Mocon method is used. The permeability is 0.04 or less (ml / line / day). Further, as the solvent barrier property of the laminated tube 10 according to the present embodiment, specifically, for example, when the average thickness of the shoulder portion 13 and the mouth portion 12 of the container is 1.0 mm, the toluene permeation amount is 0. .01 (g / line / day).
In addition, the laminate structure and film thickness of the laminated film of the trunk | drum 11 can be set so that it may have a barrier property equivalent to or higher than these shoulder part 13 and mouth part 12.

Then, the detail of the structure of the laminate tube produced by the compression molding method is demonstrated.
As shown in FIGS. 4 and 6, the metaxylylene group-containing polyamide 22 is dispersed in an island shape in the polyolefin 21, and the island-like metaxylylene group-containing polyamide 22 is stretched into a single-sided shape through a compression stretch blow process. Is done.

  In the present embodiment, the longitudinal dimension (in the X direction in FIGS. 1 to 7) of the metaxylylene group-containing polyamide 22 dispersed in the polyolefin 21 in a melt-kneaded state (hereinafter referred to as an initial state) in an extruder. When the maximum dimension), the horizontal dimension (the maximum dimension in the Y direction), and the thickness dimension (the maximum dimension in the Z direction) are each 1, the shape of the metaxylylene group-containing polyamide 22 changes as follows.

  First, when the resin composition is extruded from an extruder, the metaxylylene group-containing polyamide 22A is deformed to a longitudinal dimension of 1.5, a lateral dimension, and a thickness dimension of about 0.8 with respect to the initial state (FIG. 2, 4 and 5).

  Subsequently, by allowing the extruded resin composition to flow and solidify using a mold, the metaxylylene group-containing polyamide 12B has a longitudinal dimension of 3.0 to 4.5, a lateral dimension and a thickness with respect to the initial state. The dimension is deformed to 0.5 to 0.6 (FIGS. 3, 6 and 7).

When the initial state is 1, the area of the metaxylylene group-containing polyamide 12B in the plane direction parallel to the vertical direction and the horizontal direction is 1.5 to 2.7.
In the following description, each dimension ratio of the metaxylylene group-containing polyamide in the finally obtained laminate tube when the initial state is 1 may be referred to as “stretching degree”.

  Note that the metaxylylene group-containing polyamide in the initial state has a shape close to a sphere as a whole, and the vertical dimension, the horizontal dimension, and the thickness dimension are substantially equal. Therefore, the dimensional ratio of the metaxylylene group-containing polyamide dispersed in the polyolefin of the laminated tube obtained after molding is expressed as follows: longitudinal dimension: transverse dimension: thickness dimension = 3.0 to 4.5: 0.5 to 0.6: 0. It may be expressed as .5 to 0.6.

  That is, in this embodiment, by using the compression molding method, the area occupied exclusively by the metaxylylene group-containing polyamide 22 in the polyolefin 21 in the direction parallel to the vertical direction and the horizontal direction (direction perpendicular to the thickness direction Z) is large. Become. Thereby, permeation | transmission of oxygen, a solvent, etc. to the thickness direction in the shoulder part 13 and the opening | mouth part 12 of the laminate tube 10 can be suppressed, Therefore, the laminate tube 10 which has the outstanding oxygen barrier property and solvent barrier property can be obtained. it can.

  In addition, from the viewpoint of obtaining higher oxygen barrier properties and solvent barrier properties, the longitudinal dimension of each metaxylylene group-containing polyamide 22B dispersed in the finally obtained laminate tube 10 is 4.5 to 15.8 with respect to the initial state. The compression molding conditions are preferably adjusted so that the lateral dimension is 1.0 to 2.0 and the thickness dimension is 0.03 to 0.25, and the longitudinal dimension of the metaxylylene group-containing polyamide 22B is 9.0. More preferably, the compression molding blow conditions are adjusted so that the width dimension is 1.5 to 2.0 and the thickness dimension is 0.03 to 0.1.

  In the laminated tube 10 of this embodiment, it is not necessary for all the metaxylylene group-containing polyamides 22 dispersed in the shoulder portion 13 and the mouth portion 12 to satisfy the above conditions. It is sufficient that 50% or more of the metaxylylene group-containing polyamide 22 satisfying the above conditions among the metaxylylene group-containing polyamide 22 present in the shoulder portion 13 and the mouth portion 12, thereby providing good oxygen barrier properties, solvent barrier properties, and trunk portions. 11 can be obtained.

  As described above, according to the laminated tube 10 according to the present embodiment, the resin composition obtained by melt mixing the polyolefin, the metaxylylene group-containing polyamide, and the modified polyolefin is molded by the compression molding method. A laminated tube 10 having a single shoulder portion 13 and a mouth portion 12 having an oxygen barrier property, a solvent barrier property, and an adhesive firmness with the body portion 11 can be provided.

  In addition, the method for producing a laminated tube according to the present embodiment compresses and molds a resin composition obtained by melting and mixing polyolefin, a metaxylylene group-containing polyamide and a modified polyolefin into a body portion 11 made of a laminate film, It is a compression molding method including the process of forming the shoulder part 13 and the opening part 12. Therefore, the number of manufacturing steps of the laminate tube 10 having excellent oxygen barrier properties, solvent barrier properties, and sealing resistance can be reduced, and productivity can be improved. Further, the dimensional accuracy in the shoulder 13 and the mouth 12 can be improved (accuracy level of 0.01 mm).

  According to the method for manufacturing the laminate tube 10 according to the present embodiment, when the resin composition described above is extruded into a forming mold, in the preform state, the metaxylylene group-containing polyamide in the resin composition (particularly, polyolefin) is added. It becomes possible to disperse in a relatively layered manner to exhibit barrier properties.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  Examples according to the present invention will be described below.

<Preparation of laminate film>
In Examples and Comparative Examples described below, a film having the following layer structure was used as a laminate film serving as a body portion.
In order from the contents side,
PE / AL / PET / PE
It is. Each film thickness is
100 μm / 20 μm / 12 μm / 280 μm
It is.

<Production of shoulder and mouth>
In the examples and comparative examples described below, high-density polyethylene is used as the polyolefin, MX nylon is used as the metaxylylene group-containing polyamide, and an adhesive resin is used as the modified polyolefin.

Example 1
High density polyethylene (Made by Keiyo Polyethylene, MFR0.3, density 0.957), MX nylon (Mitsubishi Gas Chemical Co., MFR0.5), and adhesive resin (Mitsui Chemicals, MFR2.1, density 0. 927) and a resin composition having a blending ratio of high-density polyethylene, MX nylon, and adhesive resin of 80:10:10 (mass%)), and an average wall thickness of 1.0 mm by a compression molding method. The shoulder part which becomes is connected to the laminate film, a laminate tube having a total length of 120 mm and a body diameter of 45 mm is produced, and the mouth part is sealed with an aluminum film.

(Comparative Example 1)
Using high-density polyethylene (same as in Example 1), by compression molding, the shoulder with an average thickness of 1.0 mm is connected to the laminate film to produce a laminate tube with a total length of 120 mm and a body diameter of 45 mm. (The same shape as in Example 1), and the mouth was sealed with an aluminum film.

<Evaluation test 1>
About the laminated tube of Example 1 and Comparative Example 1, oxygen permeability (JIS K7126 conformity, mocon method, temperature 30 ° C., humidity 70% RH) was measured.
The results are shown in Table 1 below.

<Evaluation Test 2>
About the laminated tube of Example 1 and Comparative Example 1, the solvent permeability was measured. As an evaluation procedure, the laminate tube of Example 1 and Comparative Example 1 was filled with 100 ml of toluene, and the mouth was sealed with an aluminum film seal. And after storing these laminated tubes for 14 days in a 40 degreeC thermostat, the permeation | transmission amount of toluene was computed by measuring the weight change of a laminated tube.
The results are shown in Table 2 below.

  As shown in Table 1, it can be seen that the laminated tube of Example 1 is superior to the laminated tube not containing MX nylon of Comparative Example 1 (HDPE single layer) by about 2.5 times and has excellent oxygen barrier properties. It was. This is because the laminate tube of Example 1 is stretched in the axial direction (X direction) of the laminate tube by a compression molding method, and MX nylon in high-density polyethylene is thinner than the initial state and distributed in layers. Because it is.

  Further, as shown in Table 1, it was found that the laminate tube of Example 1 was excellent in solvent barrier properties by about 50 times compared to the laminate tube of Comparative Example 1 (HDPE single layer). This is because the laminate tube of Example 1 is stretched in the axial direction (X direction) of the laminate tube by a compression molding method, and MX nylon in high-density polyethylene is thinner than the initial state and distributed in layers. Because it is.

<Evaluation Test 3>
The laminated tube of Example 1 and Comparative Example 1 was subjected to content resistance evaluation. As an evaluation procedure, the laminate tube of Example 1 and Comparative Example 1 was filled with 100 ml of toluene, and the mouth was sealed with an aluminum film seal. And after storing those laminated tubes for 72 hours in a 60 degreeC thermostat, the external shape of the laminated tube was confirmed visually.
The results are shown in Table 2 below.

  As shown in Table 2, the laminate tube of Example 1 had no appearance, but the laminate tube (HDPE single layer) of Comparative Example 1 which does not contain MX nylon is a connection portion between the shoulder portion and the trunk portion. In the vicinity, leakage of contents occurred. This is because the laminated tube of Example 1 is connected to the laminated film with sufficient resistance.

  Examples of utilization of the present invention include contents containing solvents such as agricultural chemicals and printing inks.

2A, 2B, 2C ... mold 10A ... resin composition 10, 10B ... laminate tube 11 ... body 12 ... mouth 13 ... shoulder 14 ... thread 15 ... cap 16 ... bottom 17 ... screw groove 21 ... polyolefin 22A, 22B ... Metaxylene group-containing polyamide

Claims (7)

In the laminated tube in which the shoulder portion and the mouth portion are formed at one opening end of the barrel portion having a barrier property formed in a cylindrical shape,
The resin forming at least the shoulder and the mouth has a resin composition composed of 60 to 90% by mass of polyolefin, 2 to 35% by mass of polyamide containing metaxylylene group, and 5 to 30% by mass of modified polyolefin. ,
In the polyolefin, the metaxylylene group-containing polyamide is dispersed in an island shape, and when the vertical dimension and the horizontal dimension of the initial metaxylylene group-containing polyamide are set to 1, respectively, after the shoulder portion and the mouth portion are molded A laminate tube, wherein the metaxylylene group-containing polyamide has a longitudinal dimension of 3.0 to 4.5 and a lateral dimension of 0.5 to 0.6.   When the thickness dimension of the initial metaxylylene group-containing polyamide is 1, the thickness dimension of the metaxylylene group-containing polyamide after molding of the shoulder and the mouth is 0.5 to 0.6. The laminate tube according to claim 1.   The laminated tube according to claim 1 or 2, wherein the polyolefin is high-density polyethylene.   The laminate tube according to any one of claims 1 to 3, wherein a surface of the body portion is made of the polyolefin.   The laminate tube according to any one of claims 1 to 4, wherein the body portion has a layer made of aluminum as a barrier layer.   The laminate tube according to any one of claims 1 to 5, wherein the trunk portion has a PET layer. In the manufacturing method of the laminated tube in which the shoulder portion and the mouth portion are formed by a compression molding method on one opening end of the barrel portion having a barrier property formed in a cylindrical shape,
Preparing a resin composition obtained by melting and mixing 60 to 90% by mass of a polyolefin, 2 to 35% by mass of a metaxylylene group-containing polyamide, and 5 to 30% by mass of a modified polyolefin;
A method of manufacturing a laminated tube, comprising compression molding the resin composition to form the shoulder and the mouth.

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