JP7139607B2 - LAMINATED TUBE CONTAINER AND MANUFACTURING METHOD THEREOF - Google Patents

Description

TECHNICAL FIELD 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.

A laminate tube container has a cylindrically rolled body and a resin shoulder and mouth attached to one open end of the body.

BACKGROUND ART Laminated tube containers for protecting foods, medicines, etc. are known to have an oxygen barrier material in the body in order to prevent the contents from being oxidized and deteriorated by oxygen in the outside air. For example, a plastic film coated with a substance having oxygen barrier properties is known. Further, in order to exhibit a high degree of oxygen barrier properties, an oxygen barrier material is also known in which aluminum, silica, alumina, or the like is vapor-deposited on a film.

Thus, although an oxygen barrier material can be used for the body of a laminate tube container, it has been difficult to impart barrier properties to the mouth and shoulders. Therefore, in Patent Document 1, a resin composition containing three components, a polyolefin, a modified polyolefin, and a metaxylylene group-containing polyamide, is used as the resin composition constituting the mouth portion and the shoulder portion, and this resin composition is compression molded. proposed a laminated tube container with a mouth and a shoulder. According to this technique, the meta-xylylene group-containing polyamide is phase-separated from the polyolefin and the modified polyolefin into spheres, and the spherical meta-xylylene group-containing polyamide is compressed and flattened. Since the metaxylylene group-containing polyamide is a resin with excellent oxygen barrier performance, the flattened metaxylylene group-containing polyamide blocks the permeation of oxygen, thereby increasing the barrier properties of the mouth and shoulders.

JP 2017-159927 A

As described above, at the mouth and shoulder of the laminate tube container described in Patent Document 1, the meta-xylylene group-containing polyamide is phase-separated from other resins to form a flat shape, and this flat meta-xylylene group-containing polyamide is dispersed. It is in a state of However, when the flat meta-xylylene group-containing polyamide is dispersed, there are many gaps between the meta-xylylene group-containing polyamide and the meta-xylylene group-containing polyamide, and these gaps are composed of polyolefin and modified polyolefin having poor oxygen barrier properties. Oxygen gas flows through this gap. For this reason, the laminate tube container described in Patent Document 1 could not achieve high oxygen barrier properties.

The present invention has been made based on such circumstances, and provides a laminate tube container using a metaxylylene group-containing polyamide and polyolefin, and having a mouth portion and a shoulder portion with high oxygen barrier properties, and a method for producing the same. intended to provide

That is, the invention according to claim 1 is a laminate tube container in which a shoulder portion and a mouth portion are formed at one open end of a body portion formed in a cylindrical shape, wherein the shoulder portion and the mouth portion are formed. In a laminated tube container composed of a resin composition containing polyolefin and metaxylylene group-containing polyamide,
The polyamide is phase-separated to form a planar shape that spreads over the entire range of the shoulder and mouth in a direction that hinders permeation of oxygen from the outside to the inside of the laminate tube container. It is a laminated tube container.

Next, the invention according to claim 2 is the laminated tube container according to claim 1, wherein the resin composition contains a modified polyolefin in addition to the polyolefin and the metaxylylene group-containing polyamide.

Next, the invention according to claim 3 is the laminate tube container according to claim 1 or 2, wherein the polyolefin has a melt flow rate (MFR) of 3 to 7 g/10 min.

Next, the invention according to claim 4 is a method of manufacturing a laminated tube container by forming a shoulder portion and a mouth portion on one open end of a cylindrical body portion by compression molding. In the method for manufacturing a laminated tube container, wherein the shoulder portion and mouth portion are made of a resin composition containing polyolefin and metaxylylene group-containing polyamide,
A step of kneading the resin composition with a screw in a cylinder while heating and supplying it to one open end of the body through an adapter; and a step of molding the part and the mouth part,
The method for producing a laminated tube container is characterized in that the heating temperature in the cylinder is set to the melting start temperature of the metaxylylene group-containing polyamide or less.

Next, the invention according to claim 5 is the method for producing a laminated tube container according to claim 4, wherein the polyolefin has a melt flow rate (MFR) of 3 to 7 g/10 min.

In the laminated tube container of the present invention, the shoulder portion and the mouth portion are made of a resin composition containing a polyolefin and a metaxylylene group-containing polyamide having a high oxygen barrier property. Since the planar polyamide is spread in the direction of blocking oxygen permeation from the outside to the inside of the laminate tube container, the planar polyamide and the planar polyamide block the permeation of oxygen, exhibiting high oxygen barrier properties.

In addition, this laminate tube container can be manufactured by the method according to claim 4 or 5. That is, a resin composition containing a polyolefin and a metaxylylene group-containing polyamide is put into a cylinder, kneaded with a screw while being heated to a temperature below the melting start temperature of the taxylylene group-containing polyamide, and then passed through an adapter to one side of the body. The phase-separated polyamide can be formed into a planar shape extending in the direction of impeding oxygen permeation.

When the heating temperature in the cylinder is higher than the melting point of the polyamide, the phase-separated polyamide becomes spherical, and even if it is compressed, it only becomes a flat shape, and high oxygen barrier properties are obtained. It is not possible.

Further, even if the heating temperature in the cylinder is lower than the melting point of the polyamide, if the temperature exceeds the melting initiation temperature, the phase-separated polyamide is a mixture of spherical polyamide and planar polyamide. Although the oxygen barrier property is improved compared to the case of heating to a temperature equal to or higher than the melting point, a sufficiently high oxygen barrier property cannot be exhibited.

When the melt flow rate (MFR) of the polyolefin is outside the range of 3 to 7 g/10 min, most of the phase-separated polyamide spreads in a plane, but the spherical polyamide is also mixed. . Therefore, it is preferable to set the melt flow rate (MFR) of the polyolefin in the range of 3 to 7 g/10 min.

FIG. 1 is a perspective view showing a specific example of a laminated tube container according to the present invention. FIG. 2 is a schematic cross-sectional view showing a manufacturing process in a concrete example of the laminate tube according to the present invention. FIG. 3 is a schematic cross-sectional view showing the cross section of the mouth of the laminate tube, FIG. 3(a) shows the cross section of the mouth of a specific example of the laminate tube according to the present invention, and FIGS. shows a cross section of the opening of a concrete example of a laminate tube according to a conventional example.

Hereinafter, specific examples of the laminate tube according to the present invention will be described based on the drawings.

FIG. 1 is a perspective view showing a laminate tube, in which reference numeral 10 denotes the laminate tube.

As shown in FIG. 1, the laminated tube 10 is formed by forming a shoulder portion 12 and a mouth portion 13 at one open end (upper open end in the drawing) of a heat-resistant cylindrical body portion 11 by compression molding. At the same time, it is attached by thermal welding, and a screw thread 14 for attaching a separate cap 15 is provided on the outer peripheral surface of the mouth portion 13 . Moreover, the shoulder portion 12 and the mouth portion 13 are molded using a single layer of resin as will be described later.

It is also possible to seal the upper end of the opening 13 with a thin body having a barrier property such as aluminum foil without providing the cap 15 . As an example of this seal, it is also possible to thermally adhere a sealing material having a configuration in which a biaxially oriented polyethylene terephthalate film, an aluminum foil, and a polypropylene resin sealant layer are laminated in order from the outside to improve the sealing performance.

Further, since the bottom portion 16 of the laminate tube 10 is used as a filling port for the content, it is an unsealed opening before filling with the content, and is sealed by thermal bonding after filling with the content.

When the cap 15 is provided, it can be produced by injection molding with the same resin as the shoulder portion 12 and the mouth portion 13, and the inner peripheral surface of the side wall is threaded with the screw provided on the outer peripheral surface of the mouth portion 13. Threads 17 may be provided for screwing into thread 14 .

The body portion 11 has a tubular shape made of a laminated body having a barrier property, and has, for example, an aluminum layer, the inner surface of which is made of the resin contained in the shoulder portion 12 and the mouth portion 13, and is made of polyolefin. ing. The laminate having a barrier property of the trunk portion 11 is composed of a layer made of aluminum as a barrier layer, a PET layer, and an inorganic deposition barrier layer (alumina, silicon oxide, etc.) or a metal thin film on a base film (PET, nylon, etc.). It can have a vapor-deposited film on which layers are vapor-deposited.

The inner surface of the trunk portion 11 is preferably made of polyethylene resin in consideration of the adhesiveness with the shoulder portion 12 .

The shoulder portion 12 and the mouth portion 13 can be made of a resin composition containing polyolefin and the polyamide. In addition to these polyolefins and the polyamide, a resin composition containing modified polyolefin may be used as the material for the shoulder portion 12 and the mouth portion 13 . In addition, for the purpose of modification, thermoplastic elastomers, various copolymerized polyolefins such as EEA (ethylene-ethyl acrylate) and EMA (ethylene-methyl acrylate), ionomers, etc. may be blended. A material obtained by pulverizing burrs generated in the manufacturing process of the mouth portion 12 and defective products that did not become products may be mixed.

Next, each of these materials will be described, and then a method of manufacturing the laminate tube container of the present invention using these materials will be described.

(Meta-xylene group-containing polyamide)
The meta-xylylene group-containing polyamide has a diamine unit and a dicarboxylic acid unit, and by including it in the resin composition, it is possible to impart the effect of enhancing the oxygen barrier performance of the molded laminate tube.

The diamine unit constituting the meta-xylylene group-containing polyamide is not particularly limited, and specific examples include meta-xylylenediamine, paraxylylenediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis (Aminomethyl)cyclohexane, tetramethylenediamine, hexamethylenediamine, nonamethylenediamine, 2-methyl-1,5-pentanediamine and the like can be used.

As the meta-xylene group-containing polyimide, for example, those containing 70 mol % or more of meta-xylylenediamine units are preferable, those containing 80 mol % or more are more preferable, and those containing 90 mol % or more are even more preferable. By using a meta-xylene group-containing polyimide containing 70 mol % or more of meta-xylene diamine units in the resin composition, the gas barrier properties of the molded shoulder portion 13 and the mouth portion 12 and the joint portion between these and the body portion 11 can be efficiently improved. can be enhanced.

The dicarboxylic acid unit constituting the meta-xylene group-containing polyimide is not particularly limited, and specific examples include α,ω-aliphatic dicarboxylic acid, 1,3-cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid. Alicyclic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, xylylene dicarboxylic acid, and aromatic dicarboxylic acids such as naphthalenedicarboxylic acid can be used. Among these, isophthalic acid and 2,6-naphthalenedicarboxylic acid are preferable because they can easily obtain a polyamide having excellent barrier properties without inhibiting the polycondensation reaction in producing a metaxylylene group-containing polyamide. .

Further, the meta-xylene group-containing polyimide preferably contains 50 mol% or more of a dicarboxylic acid unit such as α,ω-aliphatic dicarboxylic acid, more preferably 60 mol% or more, and more preferably 70 mol% or more. is more preferred. By setting the dicarboxylic acid unit to 70 mol % or more, it is possible to suppress excessive deterioration in the crystallinity of the meta-xylene group-containing polyimide.

Specific examples of α,ω-aliphatic dicarboxylic acids include suberic acid, adipic acid, azelaic acid, sebacic acid, and dodecanoic acid. Among these, it is preferable to use adipic acid and sebacic acid because they are excellent in the ability to maintain good gas barrier properties and crystallinity.

In the meta-xylene group-containing polyimide, lactams such as ε-caprolactam and laurolactam, aminocaproic acid, aminoundecanoic acid, etc., as copolymer units other than the diamine unit and the dicarboxylic acid unit, within a range that does not impair the effects of the present invention. aliphatic aminocarboxylic acids,
Aromatic aminocarboxylic acids such as para-aminomethylbenzoic acid may also be included.

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

It can also be produced by directly adding a diamine to a molten dicarboxylic acid and polycondensing it. In this case, it is preferable to keep the reaction system in a uniform liquid state. Specifically, while the diamine is continuously added to the dicarboxylic acid, 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 oligoamide and polyamide to be produced.

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

The phosphorus atom-containing compound is not particularly limited, but specific examples include dimethylphosphinic acid, phenylmethylphosphinic acid, hypophosphorous acid, sodium hypophosphite, potassium hypophosphite, and hypophosphorous acid. lithium, ethyl hypophosphite, phenylphosphonous 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 , pyrophosphorous acid and the like can be used. Among these, hypophosphite metal salts such as sodium hypophosphite, potassium hypophosphite, lithium hypophosphite, etc. are highly effective in promoting the amidation reaction and are also excellent in preventing coloring. Preferred, sodium hypophosphite being particularly preferred.

The amount of the phosphorus atom-containing compound added to the meta-xylylene group-containing polyimide is preferably 1 to 500 ppm, more preferably 5 to 450 ppm in terms of phosphorus atom concentration in the meta-xylylene group-containing polyamide, and 10 to More preferably 400 ppm. Coloring of the xylylene group-containing polyamide during polycondensation can be prevented by setting the addition amount of the phosphorus atom compound within the above range.

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

Alkali metal compounds and alkaline earth metal compounds are not particularly limited, but specific examples include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, magnesium hydroxide, water Hydroxides of alkali metals and alkaline earth metals such as calcium oxide and barium hydroxide, alkali metals and alkalis such as lithium acetate, sodium acetate, potassium acetate, rubidium acetate, cesium acetate, magnesium acetate, calcium acetate and barium acetate Acetates of earth metals and the like are included.

When an alkali metal compound or alkaline earth metal compound is added to the meta-xylene group-containing polyimide, the 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 It is preferably in the range of 2.0, more preferably in the range of 0.6 to 1.8, even more preferably in the range of 0.7 to 1.5. By setting the amount of the alkali metal compound or the alkaline earth metal compound to be within the above range, it is possible to suppress the formation of gel while obtaining the amidation reaction promoting effect of the phosphorus atom-containing compound.

The meta-xylylene group-containing polyamide obtained by melt polycondensation is once taken out, pelletized, and dried before use. Moreover, in order to further increase the degree of polymerization, solid phase polymerization may be performed. A heating device used in drying or solid-phase polymerization is not particularly limited, and known methods and devices can be used. Specific examples of such a heating device include, for example, a continuous heating drying device, a rotating drum type heating device called a tumble dryer, a conical dryer, a rotary dryer, etc., and an internal heating device called a Nauta mixer. A conical heating device equipped with rotary blades and the like can be mentioned. Among these, the batch-type heating apparatus can seal the inside of the system and facilitate polycondensation in a state in which oxygen that causes coloration is removed, so it is particularly useful for solid-phase polymerization of polyamide.

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

(polyolefin)
Polyolefins having a melt flow rate (MFR) in the range of 3 to 7 g/10 min can be preferably used as polyolefins. Specifically, for example, 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, or ethylene, propylene, butene, etc. A resin composed of a copolymer of two or more kinds of olefins and a mixture thereof can be used.

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

Specific examples of unsaturated carboxylic acids or anhydrides 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, etc., and anhydrides thereof. Among these, maleic acid, maleic anhydride, and the like are preferably used.

The method for graft-copolymerizing the unsaturated carboxylic acid or its anhydride with the polyolefin to obtain the modified polyolefin is not particularly limited, and conventionally known various methods can be used. Specifically, for example, a method of melting polyolefin using an extruder or the like, adding a graft monomer and copolymerizing it, a method of dissolving polyolefin in a solvent and adding a graft monomer and copolymerizing it, and a method of copolymerizing polyolefin For example, a method of adding a graft monomer after forming an aqueous suspension and carrying out copolymerization may be mentioned.

(resin composition)
The content of the metaxylylene group-containing polyamide in the resin composition constituting the shoulder portion 12 and the mouth portion 13 is 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). On the other hand, it is preferable to make it 2 to 35% by mass. By setting the meta-xylylene group-containing polyamide in the resin composition to the above range, the barrier performance of the shoulder portion 13 and the mouth portion 12 can be efficiently improved, and the decrease in the strength of the shoulder portion 13 and the mouth portion 12 can be prevented from practical use. can be suppressed within a certain range, and the adhesiveness and barrier performance between the shoulder portion 13 and the trunk portion 11 can be reliably maintained.

In addition, the content of polyolefin in this resin composition is 60 to 90% by mass with respect to a total of 100% by mass of polyolefin, metaxylylene group-containing polyamide, and modified polyolefin (that is, 100% by mass of the resin composition). is preferred. By setting the content of the polyolefin in the resin composition within the above range, it is possible to minimize the decrease in strength of the container blended with the meta-xylylene group-containing polyamide.

In addition, the content of the modified polyolefin in the resin composition is 5 to 30% by mass with respect to the total 100% by mass of the polyolefin, the metaxylylene group-containing polyamide, and the modified polyolefin (that is, 100% by mass of the resin composition). is preferred. By setting the modified polyolefin in the resin composition to the above range, the adhesiveness between the non-adhesive polyolefin and the metaxylylene group-containing polyamide is improved, the strength of the shoulder portion 13 and the mouth portion 12 is increased, and the shoulder portion 13 is improved. and the trunk portion 11 and the barrier performance can be reliably maintained.

Further, the content of the modified polyolefin relative to the meta-xylylene group-containing polyamide in the resin composition is preferably 0.8 to 5.0 times, more preferably 1.0 to 4.5 times by mass. , 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 adhesiveness and barrier performance between the shoulder portion 13 and the body portion 11 can be reliably maintained.

(Manufacturing method of laminated tube container)
Next, this laminate tube 10 can be manufactured by a compression molding method. 2(a) to 2(c) show schematic cross-sectional views in the manufacturing process by the compression molding method.

That is, first, as the body portion 11, a tubular barrier laminate having front and back surfaces made of the same polyolefin as the shoulder portion 12 and the mouth portion 13 is prepared, and the opening at one end projects as a connection area. It is set in a state in which it is wound around a cylindrical mold 2B formed in a convex shape (see FIG. 2(b)).

Next, as shown in FIG. 2(a), the resin composition A is supplied to the extruder. The extruder is composed of three parts, a feeding part, a compression part and a metering part, and an adapter 23 is connected to the tip of the extruder.

The feeding section, compression section and metering section of the extruder are provided with a cylinder 21 and a screw 22 arranged inside the cylinder 21, and the cylinder 21 is provided with a heating device (not shown).

The supply portion is provided with a supply port 21a, and the resin composition A is supplied by charging the respective materials through the supply port 21a. The resin composition A is heated in the compressing section and kneaded and compressed by the rotation of the screw 22 . In addition, as the screw 22 rotates, it is transferred to the weighing section (the Z direction in the drawing).

It is important that the heating temperature is lower than the melting initiation temperature of the metaxylylene group-containing polyamide. When the heating temperature is higher than its melting point, the meta-xylylene group-containing polyamide melts, so that the phase-separated polyamide becomes spherical, and as described later, even if it is compressed, it only becomes a flat shape. , high oxygen barrier properties cannot be obtained.

Further, even if the heating temperature is lower than the melting point, if the temperature exceeds the melting start temperature, the phase-separated polyamide will be in a state in which spherical polyamide and planar polyamide are mixed. Although the oxygen barrier property is improved as compared with the case of heating to the above temperature, a sufficiently high oxygen barrier property cannot be exhibited.

On the other hand, when the heating temperature is lower than the melting initiation temperature of the metaxylylene group-containing polyamide, the phase-separated polyamide spreads in a plane extending in the flow direction of the resin composition A and intersects this. impede oxygen permeation in directions. In FIG. 2A, the resin composition A flows in the cylinder 21 in the Z direction, and the resin composition A in the adapter 23 flows in the A2 direction.

The metering section is a section that controls the discharge amount of the resin composition A according to the tip position of the screw 22 . That is, by bringing the tip position of the screw 22 closer to the adapter 23, the discharge amount of the resin composition A can be decreased, and by moving it away from the adapter 23, the discharge amount can be increased.

Next, the resin composition A discharged from the cylinder 21 is passed through the adapter 23 and formed in the mold 2B and the mold 2A1C which covers the mold 2B and has a female shape of the shoulder portion 13. It is put into a position that becomes a molding space (see FIG. 2(b)).

Next, as shown in FIG. 2(c), the mold 2A1B is closed at a low pressure (for example, about 784 kPa), and the resin composition is heated (mold temperature: about 80° C.) to degas. The mold 2A1B is closed at high pressure (mold clamping pressure: about 1960 kPa), the heat of the mold is used to flow and solidify the resin, and the laminate tube container 10 in which the shoulder portion 13, the mouth portion 12, and the body portion 11 are integrated. to manufacture.

(laminated tube container)
In the mouth portion 13 of the laminated tube container manufactured in this way, as shown in FIG. Shows a planar shape. Although this surface has some undulations, it is along the flow direction of the resin composition A, and therefore spreads in the direction of hindering oxygen permeation from the outside to the inside of the laminate tube container 10. This surface generally has a shape that is continuously connected from the tip of the mouth to the body, and the length of the short side is usually 50 times or more the thickness. Similarly, in the shoulder portion 12, the metaxylylene group-containing polyamide A1 is phase-separated to form a surface that expands in a direction that hinders permeation of oxygen from the outside to the inside of the laminate tube container.

A polyolefin having an MFR of 5 g/10 min is used as the polyolefin, a metaxylylene group-containing polyamide having a melting point of 230 to 240 ° C. and a melting start temperature of 210 ° C. is used as the metaxylylene group-containing polyamide A1, and the heating temperature in the cylinder 21 is set to When the laminated tube container 10 is manufactured at a temperature not higher than the melting initiation temperature of the contained polyamide, the metaxylylene group-containing polyamide A1 separates from the other resin A2 in the shoulder portion 12 and the mouth portion 13 as shown in FIG. Separately, shoulder 12 and mouth 1
A planar shape spread over the entire range of 3 was obtained. The oxygen permeability at this time was 0.0009 to 0.0014 cc/pkg·day.

On the other hand, even if the same polyolefin and metaxylylene group-containing polyamide A1 are used, when the heating temperature in the cylinder 21 is set to the melting point of the metaxylylene group-containing polyamide or higher, phase separation occurs as shown in FIG. The polyamide A1 was merely dispersed as flat dots, and the oxygen permeability of the shoulder portion 12 and mouth portion 13 was 0.0137 cc/pkg·day.

Further, when the same polyolefin and the metaxylylene group-containing polyamide A1 are used, and the heating temperature in the cylinder 21 is set to the melting point or lower and the melting start temperature or higher, the polyamide undergoes phase separation as shown in FIG. A1 shows a state in which spherical polyamide and planar polyamide are mixed, and the oxygen permeability of the shoulder portion 12 and mouth portion 13 is 0.0066 cc/pkg·day.

From this result, by setting the heating temperature in the cylinder 21 to the melting start temperature or lower of the metaxylylene group-containing polyamide, the phase-separated metaxylylene group-containing polyamide spreads in a planar manner, and as a result, remarkably high oxygen barrier properties are exhibited. is understandable.

In addition, when polyolefin with MFR 10 g/10 min is used instead of polyolefin with MFR 5 g/10 min, the same metaxylylene group-containing polyamide (melting point 230 to 240 ° C., melting start temperature 210 ° C.) A1 is used, and in cylinder 21 When the heating temperature of is below the melting initiation temperature of the metaxylylene group-containing polyamide, the phase-separated polyamide A1 in the shoulder portion 12 and the mouth portion 13 is in a state in which spherical polyamide and planarly spread polyamide are mixed. became. Its oxygen permeability was 0.0042 cc/pkg·day. From this result, it can be understood that high oxygen barrier properties are exhibited even when the MFR of polyolefin is higher than 7 g/10 min, but higher oxygen barrier properties are exhibited by using polyolefins with MFR lower than 7 g/10 min.

10: Laminated tube 11: Body 12: Shoulder 13: Mouth 14: Thread 15: Cap 16: Bottom 17: Screw groove A: Resin composition A1: Metaxylylene group-containing polyamide A2: Other resins 2A1B, 2C: Mold

Claims (5)

A laminate tube container having a shoulder and mouth formed at one open end of a body formed in a cylindrical shape, wherein the shoulder and mouth contain polyolefin and metaxylylene group-containing polyamide. In a laminate tube container composed of the composition,
The polyamide is phase-separated to form a planar shape that spreads over the entire range of the shoulder and mouth in a direction that hinders permeation of oxygen from the outside to the inside of the laminate tube container. Laminated tube container . 2. The laminated tube container according to claim 1, wherein the resin composition contains modified polyolefin in addition to polyolefin and meta-xylylene group-containing polyamide. 3. The laminated tube container according to claim 1, wherein the polyolefin has a melt flow rate (MFR) of 3 to 7 g/10 min. A method for manufacturing a laminated tube container by forming a shoulder and mouth portion on one open end of a cylindrical body portion by compression molding, wherein the shoulder portion and mouth portion are made of polyolefin and In a method for producing a laminated tube container composed of a resin composition containing a meta-xylylene group-containing polyamide,
A step of kneading the resin composition with a screw in a cylinder while heating and supplying it to one open end of the body through an adapter; and a step of molding the part and the mouth part,
A method for producing a laminated tube container, wherein the heating temperature in the cylinder is set to a melting initiation temperature or lower of the metaxylylene group-containing polyamide. 5. The method for producing a laminated tube container according to claim 4, wherein the polyolefin has a melt flow rate (MFR) of 3 to 7 g/10 min.

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